Publisher: Scientific Research Publishing   (Total: 230 journals)

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Showing 1 - 200 of 243 Journals sorted alphabetically
Advances in Aerospace Science and Technology     Open Access   (Followers: 16)
Advances in Alzheimer's Disease     Open Access   (Followers: 8)
Advances in Anthropology     Open Access   (Followers: 19)
Advances in Applied Sociology     Open Access   (Followers: 16)
Advances in Biological Chemistry     Open Access   (Followers: 9)
Advances in Bioscience and Biotechnology     Open Access   (Followers: 21)
Advances in Breast Cancer Research     Open Access   (Followers: 18)
Advances in Chemical Engineering and Science     Open Access   (Followers: 111)
Advances in Computed Tomography     Open Access   (Followers: 2)
Advances in Entomology     Open Access   (Followers: 3)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Historical Studies     Open Access   (Followers: 10)
Advances in Infectious Diseases     Open Access   (Followers: 9)
Advances in Internet of Things     Open Access   (Followers: 18)
Advances in J.ism and Communication     Open Access   (Followers: 27)
Advances in Linear Algebra & Matrix Theory     Open Access   (Followers: 5)
Advances in Literary Study     Open Access   (Followers: 1)
Advances in Lung Cancer     Open Access   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 32)
Advances in Microbiology     Open Access   (Followers: 24)
Advances in Molecular Imaging     Open Access   (Followers: 1)
Advances in Nanoparticles     Open Access   (Followers: 17)
Advances in Parkinson's Disease     Open Access   (Followers: 2)
Advances in Physical Education     Open Access   (Followers: 11)
Advances in Pure Mathematics     Open Access   (Followers: 9)
Advances in Remote Sensing     Open Access   (Followers: 53)
Advances in Reproductive Sciences     Open Access   (Followers: 1)
Advances in Sexual Medicine     Open Access   (Followers: 3)
Agricultural Sciences     Open Access   (Followers: 5)
American J. of Analytical Chemistry     Open Access   (Followers: 27)
American J. of Climate Change     Open Access   (Followers: 41)
American J. of Computational Mathematics     Open Access   (Followers: 4)
American J. of Industrial and Business Management     Open Access   (Followers: 24)
American J. of Molecular Biology     Open Access   (Followers: 4)
American J. of Operations Research     Open Access   (Followers: 6)
American J. of Plant Sciences     Open Access   (Followers: 20)
Applied Mathematics     Open Access   (Followers: 6)
Archaeological Discovery     Open Access   (Followers: 3)
Art and Design Review     Open Access   (Followers: 13)
Atmospheric and Climate Sciences     Open Access   (Followers: 32)
Beijing Law Review     Open Access   (Followers: 4)
Case Reports in Clinical Medicine     Open Access   (Followers: 3)
CellBio     Open Access  
Chinese Medicine     Open Access   (Followers: 3)
Chinese Studies     Open Access   (Followers: 4)
Circuits and Systems     Open Access   (Followers: 16)
Communications and Network     Open Access   (Followers: 13)
Computational Chemistry     Open Access   (Followers: 3)
Computational Molecular Bioscience     Open Access   (Followers: 1)
Computational Water, Energy, and Environmental Engineering     Open Access   (Followers: 5)
Creative Education     Open Access   (Followers: 14)
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
Current Urban Studies     Open Access   (Followers: 15)
Detection     Open Access   (Followers: 3)
E-Health Telecommunication Systems and Networks     Open Access   (Followers: 3)
Energy and Power Engineering     Open Access   (Followers: 23)
Engineering     Open Access   (Followers: 2)
Food and Nutrition Sciences     Open Access   (Followers: 24)
Forensic Medicine and Anatomy Research     Open Access   (Followers: 7)
Geomaterials     Open Access   (Followers: 2)
Graphene     Open Access   (Followers: 7)
Green and Sustainable Chemistry     Open Access   (Followers: 4)
Health     Open Access   (Followers: 4)
iBusiness     Open Access   (Followers: 2)
InfraMatics     Open Access  
Intelligent Control and Automation     Open Access   (Followers: 6)
Intelligent Information Management     Open Access   (Followers: 7)
Intl. J. of Analytical Mass Spectrometry and Chromatography     Open Access   (Followers: 7)
Intl. J. of Astronomy and Astrophysics     Open Access   (Followers: 34)
Intl. J. of Clean Coal and Energy     Open Access   (Followers: 2)
Intl. J. of Clinical Medicine     Open Access   (Followers: 2)
Intl. J. of Communications, Network and System Sciences     Open Access   (Followers: 9)
Intl. J. of Geosciences     Open Access   (Followers: 10)
Intl. J. of Intelligence Science     Open Access   (Followers: 3)
Intl. J. of Internet and Distributed Systems     Open Access   (Followers: 2)
Intl. J. of Medical Physics, Clinical Engineering and Radiation Oncology     Open Access   (Followers: 11)
Intl. J. of Modern Nonlinear Theory and Application     Open Access   (Followers: 2)
Intl. J. of Nonferrous Metallurgy     Open Access   (Followers: 5)
Intl. J. of Organic Chemistry     Open Access   (Followers: 9)
Intl. J. of Otolaryngology and Head & Neck Surgery     Open Access   (Followers: 5)
J. of Agricultural Chemistry and Environment     Open Access   (Followers: 3)
J. of Analytical Sciences, Methods and Instrumentation     Open Access   (Followers: 5)
J. of Applied Mathematics and Physics     Open Access   (Followers: 9)
J. of Behavioral and Brain Science     Open Access   (Followers: 7)
J. of Biomaterials and Nanobiotechnology     Open Access   (Followers: 6)
J. of Biomedical Science and Engineering     Open Access   (Followers: 1)
J. of Biophysical Chemistry     Open Access   (Followers: 3)
J. of Biosciences and Medicines     Open Access  
J. of Building Construction and Planning Research     Open Access   (Followers: 10)
J. of Cancer Therapy     Open Access   (Followers: 1)
J. of Computer and Communications     Open Access   (Followers: 1)
J. of Cosmetics, Dermatological Sciences and Applications     Open Access   (Followers: 2)
J. of Crystallization Process and Technology     Open Access   (Followers: 7)
J. of Data Analysis and Information Processing     Open Access   (Followers: 2)
J. of Diabetes Mellitus     Open Access   (Followers: 5)
J. of Electromagnetic Analysis and Applications     Open Access   (Followers: 5)
J. of Electronics Cooling and Thermal Control     Open Access   (Followers: 9)
J. of Encapsulation and Adsorption Sciences     Open Access   (Followers: 1)
J. of Environmental Protection     Open Access   (Followers: 1)
J. of Financial Risk Management     Open Access   (Followers: 7)
J. of Flow Control, Measurement & Visualization     Open Access   (Followers: 1)
J. of Geographic Information System     Open Access   (Followers: 6)
J. of Geoscience and Environment Protection     Open Access  
J. of High Energy Physics, Gravitation and Cosmology     Open Access   (Followers: 2)
J. of Human Resource and Sustainability Studies     Open Access   (Followers: 1)
J. of Immune Based Therapies, Vaccines and Antimicrobials     Open Access   (Followers: 2)
J. of Information Security     Open Access   (Followers: 11)
J. of Intelligent Learning Systems and Applications     Open Access   (Followers: 4)
J. of Materials Science and Chemical Engineering     Open Access   (Followers: 1)
J. of Mathematical Finance     Open Access   (Followers: 6)
J. of Minerals and Materials Characterization and Engineering     Open Access   (Followers: 3)
J. of Modern Physics     Open Access   (Followers: 8)
J. of Power and Energy Engineering     Open Access   (Followers: 2)
J. of Quantum Information Science     Open Access   (Followers: 4)
J. of Sensor Technology     Open Access   (Followers: 3)
J. of Service Science and Management     Open Access  
J. of Signal and Information Processing     Open Access   (Followers: 9)
J. of Software Engineering and Applications     Open Access   (Followers: 12)
J. of Surface Engineered Materials and Advanced Technology     Open Access   (Followers: 3)
J. of Sustainable Bioenergy Systems     Full-text available via subscription  
J. of Transportation Technologies     Open Access   (Followers: 13)
J. of Tuberculosis Research     Open Access   (Followers: 1)
J. of Water Resource and Protection     Open Access   (Followers: 6)
Low Carbon Economy     Open Access   (Followers: 4)
Materials Sciences and Applications     Open Access   (Followers: 2)
Microscopy Research     Open Access   (Followers: 2)
Modeling and Numerical Simulation of Material Science     Open Access   (Followers: 12)
Modern Chemotherapy     Open Access  
Modern Economy     Open Access   (Followers: 3)
Modern Instrumentation     Open Access   (Followers: 58)
Modern Mechanical Engineering     Open Access   (Followers: 66)
Modern Plastic Surgery     Open Access   (Followers: 6)
Modern Research in Catalysis     Open Access  
Modern Research in Inflammation     Open Access  
Natural Resources     Open Access  
Natural Science     Open Access   (Followers: 8)
Neuroscience & Medicine     Open Access   (Followers: 2)
New J. of Glass and Ceramics     Open Access   (Followers: 6)
Occupational Diseases and Environmental Medicine     Open Access   (Followers: 3)
Open J. of Accounting     Open Access   (Followers: 2)
Open J. of Acoustics     Open Access   (Followers: 23)
Open J. of Air Pollution     Open Access   (Followers: 4)
Open J. of Anesthesiology     Open Access   (Followers: 9)
Open J. of Animal Sciences     Open Access   (Followers: 4)
Open J. of Antennas and Propagation     Open Access   (Followers: 8)
Open J. of Apoptosis     Open Access  
Open J. of Applied Biosensor     Open Access  
Open J. of Applied Sciences     Open Access  
Open J. of Biophysics     Open Access  
Open J. of Blood Diseases     Open Access  
Open J. of Business and Management     Open Access   (Followers: 3)
Open J. of Cell Biology     Open Access   (Followers: 1)
Open J. of Civil Engineering     Open Access   (Followers: 7)
Open J. of Clinical Diagnostics     Open Access   (Followers: 1)
Open J. of Composite Materials     Open Access   (Followers: 22)
Open J. of Depression     Open Access   (Followers: 2)
Open J. of Discrete Mathematics     Open Access   (Followers: 3)
Open J. of Earthquake Research     Open Access   (Followers: 3)
Open J. of Ecology     Open Access   (Followers: 8)
Open J. of Emergency Medicine     Open Access   (Followers: 2)
Open J. of Endocrine and Metabolic Diseases     Open Access   (Followers: 1)
Open J. of Energy Efficiency     Open Access   (Followers: 1)
Open J. of Epidemiology     Open Access   (Followers: 2)
Open J. of Fluid Dynamics     Open Access   (Followers: 33)
Open J. of Forestry     Open Access   (Followers: 1)
Open J. of Gastroenterology     Open Access   (Followers: 1)
Open J. of Genetics     Open Access  
Open J. of Geology     Open Access   (Followers: 14)
Open J. of Immunology     Open Access   (Followers: 4)
Open J. of Inorganic Chemistry     Open Access   (Followers: 1)
Open J. of Inorganic Non-metallic Materials     Open Access   (Followers: 2)
Open J. of Internal Medicine     Open Access  
Open J. of Leadership     Open Access   (Followers: 18)
Open J. of Marine Science     Open Access   (Followers: 6)
Open J. of Medical Imaging     Open Access   (Followers: 2)
Open J. of Medical Microbiology     Open Access   (Followers: 4)
Open J. of Medical Psychology     Open Access  
Open J. of Medicinal Chemistry     Open Access   (Followers: 4)
Open J. of Metal     Open Access   (Followers: 1)
Open J. of Microphysics     Open Access  
Open J. of Modelling and Simulation     Open Access   (Followers: 2)
Open J. of Modern Hydrology     Open Access   (Followers: 5)
Open J. of Modern Linguistics     Open Access   (Followers: 5)
Open J. of Modern Neurosurgery     Open Access   (Followers: 2)
Open J. of Molecular and Integrative Physiology     Open Access  
Open J. of Nephrology     Open Access   (Followers: 4)
Open J. of Nursing     Open Access   (Followers: 4)
Open J. of Obstetrics and Gynecology     Open Access   (Followers: 5)
Open J. of Ophthalmology     Open Access   (Followers: 3)
Open J. of Optimization     Open Access  
Open J. of Organ Transplant Surgery     Open Access   (Followers: 1)
Open J. of Organic Polymer Materials     Open Access   (Followers: 1)
Open J. of Orthopedics     Open Access   (Followers: 3)
Open J. of Pathology     Open Access   (Followers: 2)
Open J. of Pediatrics     Open Access   (Followers: 4)
Open J. of Philosophy     Open Access   (Followers: 11)
Open J. of Physical Chemistry     Open Access  
Open J. of Political Science     Open Access   (Followers: 5)
Open J. of Polymer Chemistry     Open Access   (Followers: 12)
Open J. of Preventive Medicine     Open Access  

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Advances in Computed Tomography
Number of Followers: 2  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2169-2475 - ISSN (Online) 2169-2483
Published by Scientific Research Publishing Homepage  [230 journals]
  • Robotics, Vol. 10, Pages 109: A Single-Actuated, Cable-Driven, and
           Self-Contained Robotic Hand Designed for Adaptive Grasps

    • Authors: Negin Nikafrooz, Alexander Leonessa
      First page: 109
      Abstract: Developing a dexterous robotic hand that mimics natural human hand movements is challenging due to complicated hand anatomy. Such a practical design should address several requirements, which are often conflicting and force the designer to prioritize the main design characteristics for a given application. Therefore, in the existing designs the requirements are only partially satisfied, leading to complicated and bulky solutions. To address this gap, a novel single-actuated, cable-driven, and self-contained robotic hand is presented in this work. This five-fingered robotic hand supports 19 degrees of freedom (DOFs) and can perform a wide range of precision and power grasps. The external structure of fingers and the thumb is inspired by Pisa/IIT SoftHand, while major modifications are implemented to significantly decrease the number of parts and the effect of friction. The cable configuration is inspired by the tendon structure of the hand anatomy. Furthermore, a novel power transmission system is presented in this work. This mechanism addresses compactness and underactuation, while ensuring proper force distribution through the fingers and the thumb. Moreover, this power transmission system can achieve adaptive grasps of objects with unknown geometries, which significantly simplifies the sensory and control systems. A 3D-printed prototype of the proposed design is fabricated and its base functionality is evaluated through simulations and experiments.
      Citation: Robotics
      PubDate: 2021-09-23
      DOI: 10.3390/robotics10040109
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 110: A Robot Architecture Using ContextSLAM to
           Find Products in Unknown Crowded Retail Environments

    • Authors: Daniel Dworakowski, Christopher Thompson, Michael Pham-Hung, Goldie Nejat
      First page: 110
      Abstract: Grocery shoppers must negotiate cluttered, crowded, and complex store layouts containing a vast variety of products to make their intended purchases. This complexity may prevent even experienced shoppers from finding their grocery items, consuming a lot of their time and resulting in monetary loss for the store. To address these issues, we present a generic grocery robot architecture for the autonomous search and localization of products in crowded dynamic unknown grocery store environments using a unique context Simultaneous Localization and Mapping (contextSLAM) method. The contextSLAM method uniquely creates contextually rich maps through the online fusion of optical character recognition and occupancy grid information to locate products and aid in robot localization in an environment. The novelty of our robot architecture is in its ability to intelligently use geometric and contextual information within the context map to direct robot exploration in order to localize products in unknown environments in the presence of dynamic people. Extensive experiments were conducted with a mobile robot to validate the overall architecture and contextSLAM, including in a real grocery store. The results of the experiments showed that our architecture was capable of searching for and localizing all products in various grocery lists in different unknown environments.
      Citation: Robotics
      PubDate: 2021-09-26
      DOI: 10.3390/robotics10040110
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 111: A Simulation Study of a Planar Cable-Driven
           Parallel Robot to Transport Supplies for Patients with Contagious Diseases
           in Health Care Centers

    • Authors: Marco Carpio, Roque Saltaren, Julio Viola, Cecilia García, Juan Guerra, Juan Cely, Cristian Calderón
      First page: 111
      Abstract: Currently, a large number of investigations are being carried out in the area of robotics focused on proposing solutions in the field of health, and many of them have directed their efforts on issues related to the health emergency due to COVID-19. Considering that one of the ways to reduce the risk of contagion is by avoiding contact and closeness between people when exchanging supplies such as food, medicine, clothing, etc., this work proposes the use of a planar cable-driven parallel robot for the transport of supplies in hospitals whose room distribution has planar architecture. The robot acts in accordance with a procedure proposed for each task to be carried out, which includes the process of disinfection (based on Ultraviolet-C light) of the supplies transported inside the robot’s end effector. The study presents a design proposal for the geometry of the planar cable-driven parallel robots and its end effector, as well as the software simulations that allow evaluating the robot’s movement trajectories and the responses of the position control system based on Fuzzy-PID controllers.
      Citation: Robotics
      PubDate: 2021-09-30
      DOI: 10.3390/robotics10040111
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 112: A Suite of Robotic Solutions for Nuclear
           Waste Decommissioning

    • Authors: Ivan Vitanov, Ildar Farkhatdinov, Brice Denoun, Francesca Palermo, Ata Otaran, Joshua Brown, Bukeikhan Omarali, Taqi Abrar, Miles Hansard, Changjae Oh, Stefan Poslad, Chen Liu, Hareesh Godaba, Ketao Zhang, Lorenzo Jamone, Kaspar Althoefer
      First page: 112
      Abstract: Dealing safely with nuclear waste is an imperative for the nuclear industry. Increasingly, robots are being developed to carry out complex tasks such as perceiving, grasping, cutting, and manipulating waste. Radioactive material can be sorted, and either stored safely or disposed of appropriately, entirely through the actions of remotely controlled robots. Radiological characterisation is also critical during the decommissioning of nuclear facilities. It involves the detection and labelling of radiation levels, waste materials, and contaminants, as well as determining other related parameters (e.g., thermal and chemical), with the data visualised as 3D scene models. This paper overviews work by researchers at the QMUL Centre for Advanced Robotics (ARQ), a partner in the UK EPSRC National Centre for Nuclear Robotics (NCNR), a consortium working on the development of radiation-hardened robots fit to handle nuclear waste. Three areas of nuclear-related research are covered here: human–robot interfaces for remote operations, sensor delivery, and intelligent robotic manipulation.
      Citation: Robotics
      PubDate: 2021-10-07
      DOI: 10.3390/robotics10040112
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 113: Robot Anticipation Learning System for Ball

    • Authors: Diogo Carneiro, Filipe Silva, Petia Georgieva
      First page: 113
      Abstract: Catching flying objects is a challenging task in human–robot interaction. Traditional techniques predict the intersection position and time using the information obtained during the free-flying ball motion. A common pain point in these systems is the short ball flight time and uncertainties in the ball’s trajectory estimation. In this paper, we present the Robot Anticipation Learning System (RALS) that accounts for the information obtained from observation of the thrower’s hand motion before the ball is released. RALS takes extra time for the robot to start moving in the direction of the target before the opponent finishes throwing. To the best of our knowledge, this is the first robot control system for ball-catching with anticipation skills. Our results show that the information fused from both throwing and flying motions improves the ball-catching rate by up to 20% compared to the baseline approach, with the predictions relying only on the information acquired during the flight phase.
      Citation: Robotics
      PubDate: 2021-10-15
      DOI: 10.3390/robotics10040113
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 114: Reuleaux Triangle–Based Two Degrees of
           Freedom Bipedal Robot

    • Authors: Jiteng Yang, Wael Saab, Yujiong Liu, Pinhas Ben-Tzvi
      First page: 114
      Abstract: This paper presents the design, modeling, analysis, and experimental results of a novel bipedal robotic system that utilizes two interconnected single degree-of-freedom (DOF) leg mechanisms to produce stable forward locomotion and steering. The single DOF leg is actuated via a Reuleaux triangle cam-follower mechanism to produce a constant body height foot trajectory. Kinematic analysis and dimension selection of the Reuleaux triangle mechanism is conducted first to generate the desired step height and step length. Leg sequencing is then designed to allow the robot to maintain a constant body height and forward walking velocity. Dynamic simulations and experiments are conducted to evaluate the walking and steering performance. The results show that the robot is able to control its body orientation, maintain a constant body height, and achieve quasi-static locomotion stability.
      Citation: Robotics
      PubDate: 2021-10-16
      DOI: 10.3390/robotics10040114
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 115: Inverse Kinematic Control of a Delta Robot
           Using Neural Networks in Real-Time

    • Authors: Akram Gholami, Taymaz Homayouni, Reza Ehsani, Jian-Qiao Sun
      First page: 115
      Abstract: This paper presents an inverse kinematic controller using neural networks for trajectory controlling of a delta robot in real-time. The developed control scheme is purely data-driven and does not require prior knowledge of the delta robot kinematics. Moreover, it can adapt to the changes in the kinematics of the robot. For developing the controller, the kinematic model of the delta robot is estimated by using neural networks. Then, the trained neural networks are configured as a controller in the system. The parameters of the neural networks are updated while the robot follows a path to adaptively compensate for modeling uncertainties and external disturbances of the control system. One of the main contributions of this paper is to show that updating the parameters of neural networks offers a smaller tracking error in inverse kinematic control of a delta robot with consideration of joint backlash. Different simulations and experiments are conducted to verify the proposed controller. The results show that in the presence of external disturbance, the error in trajectory tracking is bounded, and the negative effect of joint backlash in trajectory tracking is reduced. The developed method provides a new approach to the inverse kinematic control of a delta robot.
      Citation: Robotics
      PubDate: 2021-10-16
      DOI: 10.3390/robotics10040115
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 116: A Mixed-Initiative Formation Control
           Strategy for Multiple Quadrotors

    • Authors: George C. Karras, Charalampos P. Bechlioulis, George K. Fourlas, Kostas J. Kyriakopoulos
      First page: 116
      Abstract: In this paper, we present a mixed-initiative motion control strategy for multiple quadrotor aerial vehicles. The proposed approach incorporates formation specifications and motion-planning commands as well as inputs by a human operator. More specifically, we consider a leader–follower aerial robotic system, which autonomously attains a specific geometrical formation, by regulating the distances among neighboring agents while avoiding inter-robot collisions. The desired formation is realized by a decentralized prescribed performance control strategy, resulting in a low computational complexity implementation with guaranteed robustness and accurate formation establishment. The multi-robot system is safely guided towards goal configurations, by employing a properly defined navigation function that provides appropriate motion commands to the leading vehicle, which is the only one that has knowledge of the workspace and the goal configurations. Additionally, the overall framework incorporates human commands that dictate the motion of the leader via a teleoperation interface. The resulting mixed-initiative control system has analytically guaranteed stability and convergence properties. A realistic simulation study, considering a team of five quadrotors operating in a cluttered environment, was carried out to demonstrate the performance of the proposed strategy.
      Citation: Robotics
      PubDate: 2021-10-26
      DOI: 10.3390/robotics10040116
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 117: Topological Analysis of a Novel Compact
           Omnidirectional Three-Legged Robot with Parallel Hip Structures Regarding
           Locomotion Capability and Load Distribution

    • Authors: David Feller, Christian Siemers
      First page: 117
      Abstract: In this study, a novel design for a compact, lightweight, agile, omnidirectional three-legged robot involving legs with four degrees of freedom, utilizing an spherical parallel mechanism with an additional non-redundant central support joint for the robot hip structure is proposed. The general design and conceptual ideas for the robot are presented, targeting a close match of the well-known SLIP-model. CAD models, 3d-printed prototypes, and proof-of-concept multi-body simulations are shown, investigating the feasibility to employ a geometrically dense spherical parallel manipulator with completely spherically shaped shell-type parts for the highly force-loaded application in the legged robot hip mechanism. Furthermore, in this study, an analytic expression is derived, yielding the calculation of stress forces acting inside the linkage structures, by directly constructing the manipulator hip Jacobian inside the force domain.
      Citation: Robotics
      PubDate: 2021-10-31
      DOI: 10.3390/robotics10040117
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 118: Untethered Origami Worm Robot with Diverse
           Multi-Leg Attachments and Responsive Motions under Magnetic Actuation

    • Authors: Manivannan Sivaperuman Kalairaj, Catherine Jiayi Cai, Pavitra S, Hongliang Ren
      First page: 118
      Abstract: Nowadays, origami folding in combination with actuation mechanisms can offer deployable structure design, yield compliance, and have several properties of soft material. An easy complex folding pattern can yield an array of functionalities in actuated hinges or active spring elements. This paper presents various cylinder origami robot designs that can be untethered magnetically actuated. The different designs are analyzed and compared to achieve the following three types of motion: Peristaltic, rolling, and turning in different environments, namely, board, sandpaper, and sand. The proposed origami robot is able translate 53 mm in peristaltic motion within 20 s and is able to roll one complete cycle in 1 s and can turn ≈180∘ in 1.5 s. The robot also demonstrated a peristaltic locomotion at a speed of ≈2.5 mm s−1, ≈1.9 mm s−1, and ≈1.3 mm s−1 in board, sandpaper, and sand respectively; rolling motion at a speed of 1 cycle s−1, ≈0.66 cycles s−1, and ≈0.33 cycles s−1 in board, sandpaper, and sand respectively; and turning motion of ≈180∘, ≈83∘, and ≈58∘ in board, sandpaper, and sand respectively. The evaluation of the robotic motion and actuation is discussed in detail in this paper.
      Citation: Robotics
      PubDate: 2021-11-01
      DOI: 10.3390/robotics10040118
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 119: A Low-Cost and Semi-Autonomous Robotic
           Scanning System for Characterising Radiological Waste

    • Authors: Stephen David Monk, Craig West, Manuel Bandala, Nile Dixon, Allahyar Montazeri, C. James Taylor, David Cheneler
      First page: 119
      Abstract: A novel, semi-autonomous radiological scanning system for inspecting irregularly shaped and radiologically uncharacterised objects in various orientations is presented. The system utilises relatively low cost, commercial-off-the-shelf (COTS) electronic components, and is intended for use within relatively low to medium radioactive dose environments. To illustrate the generic concepts, the combination of a low-cost COTS vision system, a six DoF manipulator and a gamma radiation spectrometer are investigated. Three modes of vision have been developed, allowing a remote operator to choose the most appropriate algorithm for the task. The robot arm subsequently scans autonomously across the selected object, determines the scan positions and enables the generation of radiological spectra using the gamma spectrometer. These data inform the operator of any likely radioisotopes present, where in the object they are located and thus whether the object should be treated as LLW, ILW or HLW.
      Citation: Robotics
      PubDate: 2021-11-02
      DOI: 10.3390/robotics10040119
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 120: Personalization and Localization in
           Human-Robot Interaction: A Review of Technical Methods

    • Authors: Mehdi Hellou, Norina Gasteiger, Jong Yoon Lim, Minsu Jang, Ho Seok Ahn
      First page: 120
      Abstract: Personalization and localization are important when developing social robots for different sectors, including education, industry, healthcare or restaurants. This allows for an adjustment of robot behaviors according to the needs, preferences or personality of an individual when referring to personalization or to the social conventions or the culture of a country when referring to localization. However, there are different models that enable personalization and localization presented in the current literature, each with their advantages and drawbacks. This work aims to help researchers in the field of social robotics by reviewing and analyzing different papers in this domain. We specifically focus our review by exploring different robots that employ distinct models for the adaptation of the robot to its environment. Additionally, we study an array of methods used to adapt the nonverbal and verbal skills of social robots, including state-of-the-art techniques in artificial intelligence.
      Citation: Robotics
      PubDate: 2021-11-03
      DOI: 10.3390/robotics10040120
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 121: Dynamically Balanced Pointing System for
           CubeSats: Study and 3D Printing Manufacturing

    • Authors: Nicholas Sesto Gorella, Matteo Caruso, Paolo Gallina, Stefano Seriani
      First page: 121
      Abstract: The increasing presence of additive manufacturing (AM) in the space sector prompted us to investigate the feasibility of a single degree of freedom (DoF) pointing system (PS) made by means of a compound planetary gear train system (C-PGTS) integrating a dynamic balancing system (DBS) and entirely realized in AM. We analyzed in detail the dynamics of the system dealing with the design and the realization of the prototype. Of fundamental importance for this paper is the careful selection of materials for AM suitable for the prohibitive conditions of space. The results, deriving from the comparison between the experimental part and the simulations, underline the correct dimensioning of the PS and the fundamental importance of DBS in maintaining the satellite attitude. The results also confirm the capabilities of AM in the production of complex mechanical systems, allowing high precision, combined with interesting mechanical properties and low weight.This suggests the potential of AM in the space domain, both for structural parts and active components, such as those listed in this work.
      Citation: Robotics
      PubDate: 2021-11-08
      DOI: 10.3390/robotics10040121
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 122: Multi-Robot Routing Problem with
           Min–Max Objective

    • Authors: Jennifer David, Thorsteinn Rögnvaldsson
      First page: 122
      Abstract: In this paper, we study the “Multi-Robot Routing problem” with min–max objective (MRR-MM) in detail. It involves the assignment of sequentially ordered tasks to robots such that the maximum cost of the slowest robot is minimized. The problem description, the different types of formulations, and the methods used across various research communities are discussed in this paper. We propose a new problem formulation by treating this problem as a permutation matrix. A comparative study is done between three methods: Stochastic simulated annealing, deterministic mean-field annealing, and a heuristic-based graph search method. Each method is investigated in detail with several data sets (simulation and real-world), and the results are analysed and compared with respect to scalability, computational complexity, optimality, and its application to real-world scenarios. The paper shows that the heuristic method produces results very quickly with good scalability. However, the solution quality is sub-optimal. On the other hand, when optimal or near-optimal results are required with considerable computational resources, the simulated annealing method proves to be more efficient. However, the results show that the optimal choice of algorithm depends on the dataset size and the available computational budget. The contribution of the paper is three-fold: We study the MRR-MM problem in detail across various research communities. This study also shows the lack of inter-research terminology that has led to different names for the same problem. Secondly, formulating the task allocation problem as a permutation matrix formulation has opened up new approaches to solve this problem. Thirdly, we applied our problem formulation to three different methods and conducted a detailed comparative study using real-world and simulation data.
      Citation: Robotics
      PubDate: 2021-11-09
      DOI: 10.3390/robotics10040122
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 123: Bio-Inspired Conceptual Mechanical Design
           and Control of a New Human Upper Limb Exoskeleton

    • Authors: Narek Zakaryan, Mikayel Harutyunyan, Yuri Sargsyan
      First page: 123
      Abstract: Safe operation, energy efficiency, versatility and kinematic compatibility are the most important aspects in the design of rehabilitation exoskeletons. This paper focuses on the conceptual bio-inspired mechanical design and equilibrium point control (EP) of a new human upper limb exoskeleton. Considering the upper limb as a multi-muscle redundant system, a similar over-actuated but cable-driven mechatronic system is developed to imitate upper limb motor functions. Additional torque adjusting systems at the joints allow users to lift light weights necessary for activities of daily living (ADL) without increasing electric motor powers of the device. A theoretical model of the “ideal” artificial muscle exoskeleton is also developed using Hill’s natural muscle model. Optimal design parameters of the exoskeleton are defined using the differential evolution (DE) method as a technique of a multi-objective optimization. The proposed cable-driven exoskeleton was then fabricated and tested on a healthy subject. Results showed that the proposed system fulfils the desired aim properly, so that it can be utilized in the design of rehabilitation robots. Further studies may include a spatial mechanism design, which is especially important for the shoulder rehabilitation, and development of reinforcement learning control algorithms to provide more efficient rehabilitation treatment.
      Citation: Robotics
      PubDate: 2021-11-12
      DOI: 10.3390/robotics10040123
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 124: Unified Parameterization and Calibration of
           Serial, Parallel, and Hybrid Manipulators

    • Authors: Benjamin L. Moser, Joshua A. Gordon, Andrew J. Petruska
      First page: 124
      Abstract: In this work, we present methods allowing parallel, hybrid, and serial manipulators to be analyzed, calibrated, and controlled with the same analytical tools. We introduce a general approach to describe any robotic manipulator using established serial-link representations. We use this framework to generate analytical kinematic and calibration Jacobians for general manipulator constructions using null space constraints and extend the methods to hybrid manipulator types with complex geometry. We leverage the analytical Jacobians to develop detailed expressions for post-calibration pose uncertainties that are applied to describe the relationship between data set size and post-calibration uncertainty. We demonstrate the calibration of a hybrid manipulator assembled from high precision calibrated industrial components resulting in 91.1 μm RMS position error and 71.2 μrad RMS rotation error, representing a 46.7% reduction compared to the baseline calibration of assembly offsets.
      Citation: Robotics
      PubDate: 2021-11-17
      DOI: 10.3390/robotics10040124
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 125: OntoSLAM: An Ontology for Representing
           Location and Simultaneous Mapping Information for Autonomous Robots

    • Authors: Maria A. Cornejo-Lupa, Yudith Cardinale, Regina Ticona-Herrera, Dennis Barrios-Aranibar, Manoel Andrade, Jose Diaz-Amado
      First page: 125
      Abstract: Autonomous robots are playing an important role to solve the Simultaneous Localization and Mapping (SLAM) problem in different domains. To generate flexible, intelligent, and interoperable solutions for SLAM, it is a must to model the complex knowledge managed in these scenarios (i.e., robots characteristics and capabilities, maps information, locations of robots and landmarks, etc.) with a standard and formal representation. Some studies have proposed ontologies as the standard representation of such knowledge; however, most of them only cover partial aspects of the information managed by SLAM solutions. In this context, the main contribution of this work is a complete ontology, called OntoSLAM, to model all aspects related to autonomous robots and the SLAM problem, towards the standardization needed in robotics, which is not reached until now with the existing SLAM ontologies. A comparative evaluation of OntoSLAM with state-of-the-art SLAM ontologies is performed, to show how OntoSLAM covers the gaps of the existing SLAM knowledge representation models. Results show the superiority of OntoSLAM at the Domain Knowledge level and similarities with other ontologies at Lexical and Structural levels. Additionally, OntoSLAM is integrated into the Robot Operating System (ROS) and Gazebo simulator to test it with Pepper robots and demonstrate its suitability, applicability, and flexibility. Experiments show how OntoSLAM provides semantic benefits to autonomous robots, such as the capability of inferring data from organized knowledge representation, without compromising the information for the application and becoming closer to the standardization needed in robotics.
      Citation: Robotics
      PubDate: 2021-11-21
      DOI: 10.3390/robotics10040125
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 126: A Laser Vision System for Relative 3-D
           Posture Estimation of an Underwater Vehicle with Hemispherical Optics

    • Authors: Christos C. Constantinou, George P. Georgiades, Savvas G. Loizou
      First page: 126
      Abstract: This paper describes the development and experimental validation of algorithms for a novel laser vision system (LVS), suitable for measuring the relative posture from both solid and mesh-like targets in underwater environments. The system was developed in the framework of the AQUABOT project, a research project dedicated to the development of an underwater robotic system for inspection of offshore aquaculture installations. In particular, an analytical model for three-medium refraction that takes into account the nonlinear hemispherical optics for image rectification has been developed. The analytical nature of the model allows the online estimation of the refractive index of the external medium. The proposed LVS consists of three line-lasers within the field of view of the underwater robot camera. The algorithms that have been developed in this work provide appropriately filtered point-cloud datasets from each laser, as well as high-level information such as distance and relative orientation of the target with respect to the ROV. In addition, an automatic calibration procedure, along with the accompanying hardware for the underwater laser vision system has been developed to reduce the calibration overhead required by regular maintenance operations for underwater robots operating in seawater. Furthermore, a spatial image filter was developed for discriminating between mesh and non-mesh-like targets in the LVS measurements. Finally, a set of experiments was carried out in a controlled laboratory environment, as well as in real conditions at offshore aquaculture installations demonstrating the performance of the system.
      Citation: Robotics
      PubDate: 2021-11-22
      DOI: 10.3390/robotics10040126
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 127: Multi-Objective Swarm Intelligence
           Trajectory Generation for a 7 Degree of Freedom Robotic Manipulator

    • Authors: Aryslan Malik, Troy Henderson, Richard Prazenica
      First page: 127
      Abstract: This work is aimed to demonstrate a multi-objective joint trajectory generation algorithm for a 7 degree of freedom (DoF) robotic manipulator using swarm intelligence (SI)—product of exponentials (PoE) combination. Given a priori knowledge of the end-effector Cartesian trajectory and obstacles in the workspace, the inverse kinematics problem is tackled by SI-PoE subject to multiple constraints. The algorithm is designed to satisfy finite jerk constraint on end-effector, avoid obstacles, and minimize control effort while tracking the Cartesian trajectory. The SI-PoE algorithm is compared with conventional inverse kinematics algorithms and standard particle swarm optimization (PSO). The joint trajectories produced by SI-PoE are experimentally tested on Sawyer 7 DoF robotic arm, and the resulting torque trajectories are compared.
      Citation: Robotics
      PubDate: 2021-11-27
      DOI: 10.3390/robotics10040127
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 128: A Novel, Oriented to Graphs Model of Robot
           Arm Dynamics

    • Authors: George Boiadjiev, Evgeniy Krastev, Ivan Chavdarov, Lyubomira Miteva
      First page: 128
      Abstract: Robotics is an interdisciplinary field and there exist several well-known approaches to represent the dynamics model of a robot arm. The robot arm is an open kinematic chain of links connected through rotational and translational joints. In the general case, it is very difficult to obtain explicit expressions for the forces and the torques in the equations where the driving torques of the actuators produce desired motion of the gripper. The robot arm control depends significantly on the accuracy of the dynamic model. In the existing literature, the complexity of the dynamic model is reduced by linearization techniques or techniques like machine learning for the identification of unmodelled dynamics. This paper proposes a novel approach for deriving the equations of motion and the actuator torques of a robot arm with an arbitrary number of joints. The proposed approach for obtaining the dynamic model in closed form employs graph theory and the orthogonality principle, a powerful concept that serves as a generalization for the law of conservation of energy. The application of this approach is demonstrated using a 3D-printed planar robot arm with three degrees of freedom. Computer experiments for this robot are executed to validate the dynamic characteristics of the mathematical model of motion obtained by the application of the proposed approach. The results from the experiments are visualized and discussed in detail.
      Citation: Robotics
      PubDate: 2021-11-28
      DOI: 10.3390/robotics10040128
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 129: Going Hands-Free: MagnetoSuture™ for
           Untethered Guided Needle Penetration of Human Tissue Ex Vivo

    • Authors: Lamar O. Mair, Sagar Chowdhury, Xiaolong Liu, Onder Erin, Oleg Udalov, Suraj Raval, Benjamin Johnson, Sahar Jafari, David J. Cappelleri, Yancy Diaz-Mercado, Axel Krieger, Irving N. Weinberg
      First page: 129
      Abstract: The application of force in surgical settings is typically accomplished via physical tethers to the surgical tool. While physical tethers are common and critical, some internal surgical procedures may benefit from a tetherless operation of needles, possibly reducing the number of ports in the patient or the amount of tissue damage caused by tools used to manipulate needles. Magnetic field gradients can dynamically apply kinetic forces to magnetizable objects free of such tethers, possibly enabling ultra-minimally invasive robotic surgical procedures. We demonstrate the untethered manipulation of a suture needle in vitro, exemplified by steering through narrow holes, as well as needle penetration through excised rat and human tissues. We present proof of principle manipulations for the fully untethered control of a minimally modified, standard stainless steel surgical suture needle.
      Citation: Robotics
      PubDate: 2021-12-01
      DOI: 10.3390/robotics10040129
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 130: Feasibility and Performance Validation of a
           Leap Motion Controller for Upper Limb Rehabilitation

    • Authors: Marcus R. S. B. de de Souza, Rogério S. Gonçalves, Giuseppe Carbone
      First page: 130
      Abstract: The leap motion controller is a commercial low-cost marker-less optical sensor that can track the motion of a human hand by recording various parameters. Upper limb rehabilitation therapy is the treatment of people having upper limb impairments, whose recovery is achieved through continuous motion exercises. However, the repetitive nature of these exercises can be interpreted as boring or discouraging while patient motivation plays a key role in their recovery. Thus, serious games have been widely used in therapies for motivating patients and making the therapeutic process more enjoyable. This paper explores the feasibility, accuracy, and repeatability of a leap motion controller (LMC) to be applied in combination with a serious game for upper limb rehabilitation. Experimental feasibility tests are carried out by using an industrial robot that replicates the upper limb motions and is tracked by using an LMC. The results suggest a satisfactory performance in terms of tracking accuracy although some limitations are identified and discussed in terms of measurable workspace.
      Citation: Robotics
      PubDate: 2021-12-04
      DOI: 10.3390/robotics10040130
      Issue No: Vol. 10, No. 4 (2021)
  • Robotics, Vol. 10, Pages 83: Effects of Temperature and Mounting
           Configuration on the Dynamic Parameters Identification of Industrial

    • Authors: Andrea Raviola, Roberto Guida, Andrea De Martin, Stefano Pastorelli, Stefano Mauro, Massimo Sorli
      First page: 83
      Abstract: Dynamic parameters are crucial for the definition of high-fidelity models of industrial manipulators. However, since they are often partially unknown, a mathematical model able to identify them is discussed and validated with the UR3 and the UR5 collaborative robots from Universal Robots. According to the acquired experimental data, this procedure allows for reducing the error on the estimated joint torques of about 90% with respect to the one obtained using only the information provided by the manufacturer. The present research also highlights how changes in the robot operating conditions affect its dynamic behavior. In particular, the identification process has been applied to a data set obtained commanding the same trajectory multiple times to both robots under rising joints temperatures. Average reductions of the viscous friction coefficients of about 20% and 17% for the UR3 and the UR5 robots, respectively, have been observed. Moreover, it is shown how the manipulator mounting configuration affects the number of the base dynamic parameters necessary to properly estimate the robots’ joints torques. The ability of the proposed model to take into account different mounting configurations is then verified by performing the identification procedure on a data set generated through a digital twin of a UR5 robot mounted on the ceiling.
      Citation: Robotics
      PubDate: 2021-06-29
      DOI: 10.3390/robotics10030083
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 84: Model Predictive Control for Cooperative
           Transportation with Feasibility-Aware Policy

    • Authors: Badr Elaamery, Massimo Pesavento, Teresa Aldovini, Nicola Lissandrini, Giulia Michieletto, Angelo Cenedese
      First page: 84
      Abstract: The transportation of large payloads can be made possible with Multi-Robot Systems (MRS) implementing cooperative strategies. In this work, we focus on the coordinated MRS trajectory planning task exploiting a Model Predictive Control (MPC) framework addressing both the acting robots and the transported load. In this context, the main challenge is the possible occurrence of a temporary mismatch among agents’ actions with consequent formation errors that can cause severe damage to the carried load. To mitigate this risk, the coordination scheme may leverage a leader–follower approach, in which a hierarchical strategy is in place to trade-off between the task accomplishment and the dynamics and environment constraints. Nonetheless, particularly in narrow spaces or cluttered environments, the leader’s optimal choice may lead to trajectories that are infeasible for the follower and the load. To this aim, we propose a feasibility-aware leader–follower strategy, where the leader computes a reference trajectory, and the follower accounts for its own and the load constraints; moreover, the follower is able to communicate the trajectory infeasibility to the leader, which reacts by temporarily switching to a conservative policy. The consistent MRS co-design is allowed by the MPC formulation, for both the leader and the follower: here, the prediction capability of MPC is key to guarantee a correct and efficient execution of the leader–follower coordinated action. The approach is formally stated and discussed, and a numerical campaign is conducted to validate and assess the proposed scheme, with respect to different scenarios with growing complexity.
      Citation: Robotics
      PubDate: 2021-06-30
      DOI: 10.3390/robotics10030084
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 85: Robot-Assisted Glovebox Teleoperation for
           Nuclear Industry

    • Authors: Ozan Tokatli, Pragna Das, Radhika Nath, Luigi Pangione, Alessandro Altobelli, Guy Burroughes, Emil T. Jonasson, Matthew F. Turner, Robert Skilton
      First page: 85
      Abstract: The nuclear industry has some of the most extreme environments in the world, with radiation levels and extremely harsh conditions restraining human access to many facilities. One method for enabling minimal human exposure to hazards under these conditions is through the use of gloveboxes that are sealed volumes with controlled access for performing handling. While gloveboxes allow operators to perform complex handling tasks, they put operators at considerable risk from breaking the confinement and, historically, serious examples including punctured gloves leading to lifetime doses have occurred. To date, robotic systems have had relatively little impact on the industry, even though it is clear that they offer major opportunities for improving productivity and significantly reducing risks to human health. This work presents the challenges of robotic and AI solutions for nuclear gloveboxes, and introduces a step forward for bringing cutting-edge technology to gloveboxes. The problem statement and challenges are highlighted and then an integrated demonstrator is proposed for robotic handling in nuclear gloveboxes for nuclear material handling. The proposed approach spans from tele-manipulation to shared autonomy, computer vision solutions for robotic manipulation to machine learning solutions for condition monitoring.
      Citation: Robotics
      PubDate: 2021-07-03
      DOI: 10.3390/robotics10030085
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 86: Simulating Ionising Radiation in Gazebo for
           Robotic Nuclear Inspection Challenges

    • Authors: Thomas Wright, Andrew West, Mauro Licata, Nick Hawes, Barry Lennox
      First page: 86
      Abstract: The utilisation of robots in hazardous nuclear environments has potential to reduce risk to humans. However, historical use has been largely limited to specific missions rather than broader industry-wide adoption. Testing and verification of robotics in realistic scenarios is key to gaining stakeholder confidence but hindered by limited access to facilities that contain radioactive materials. Simulations offer an alternative to testing with actual radioactive sources, provided they can readily describe the behaviour of robotic systems and ionising radiation within the same environment. This work presents a quick and easy way to generate simulated but realistic deployment scenarios and environments which include ionising radiation, developed to work within the popular robot operating system compatible Gazebo physics simulator. Generated environments can be evolved over time, randomly or user-defined, to simulate the effects of degradation, corrosion or to alter features of certain objects. Interaction of gamma radiation sources within the environment, as well as the response of simulated detectors attached to mobile robots, is verified against the MCNP6 Monte Carlo radiation transport code. The benefits these tools provide are highlighted by inclusion of three real-world nuclear sector environments, providing the robotics community with opportunities to assess the capabilities of robotic systems and autonomous functionalities.
      Citation: Robotics
      PubDate: 2021-07-07
      DOI: 10.3390/robotics10030086
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 87: Smart Cleaner: A New Autonomous Indoor
           Disinfection Robot for Combating the COVID-19 Pandemic

    • Authors: Kaicheng Ruan, Zehao Wu, Qingsong Xu
      First page: 87
      Abstract: The COVID-19 pandemic imposes an increasing demand for service robots as a substitute for humans to conduct various types of work in contaminated areas. Such work includes logistics, patient care, and disinfection, which can reduce the risk of human exposure to the highly contagious and deadly virus. This paper presents the design and development of Smart Cleaner, which is a new cost-effective autonomous indoor disinfection robot. It integrates a wheeled mobile robot platform and a hydrogen peroxide atomization device for automated disinfection operation in the complex indoor environment. Through the system integration of various hardware components and software programming, a prototype of the disinfection robot has been fabricated for experimental investigation. A simulation study of the drymist hydrogen peroxide disinfection model was carried out to understand the diffusion of disinfectant in a room environment. The effectiveness of the developed robot was verified in practical scenarios, such as hospital, hotel, office, and laboratory. The effect of disinfection was validated by a qualified third-party testing agency. Results demonstrate the high efficiency of the developed disinfection robot dedicated to autonomous indoor disinfection work.
      Citation: Robotics
      PubDate: 2021-07-12
      DOI: 10.3390/robotics10030087
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 88: Maxwell Points of Dynamical Control Systems
           Based on Vertical Rolling Disc—Numerical Solutions

    • Authors: Marek Stodola, Matej Rajchl, Martin Brablc, Stanislav Frolík, Václav Křivánek
      First page: 88
      Abstract: We study two nilpotent affine control systems derived from the dynamic and control of a vertical rolling disc that is a simplification of a differential drive wheeled mobile robot. For both systems, their controllable Lie algebras are calculated and optimal control problems are formulated, and their Hamiltonian systems of ODEs are derived using the Pontryagin maximum principle. These optimal control problems completely determine the energetically optimal trajectories between two states. Then, a novel numerical algorithm based on optimisation for finding the Maxwell points is presented and tested on these control systems. The results show that the use of such numerical methods can be beneficial in cases where common analytical approaches fail or are impractical.
      Citation: Robotics
      PubDate: 2021-07-12
      DOI: 10.3390/robotics10030088
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 89: A Multiple Level-of-Detail 3D Data
           Transmission Approach for Low-Latency Remote Visualisation in
           Teleoperation Tasks

    • Authors: Salvador Pacheco-Gutierrez, Hanlin Niu, Ipek Caliskanelli, Robert Skilton
      First page: 89
      Abstract: In robotic teleoperation, the knowledge of the state of the remote environment in real time is paramount. Advances in the development of highly accurate 3D cameras able to provide high-quality point clouds appear to be a feasible solution for generating live, up-to-date virtual environments. Unfortunately, the exceptional accuracy and high density of these data represent a burden for communications requiring a large bandwidth affecting setups where the local and remote systems are particularly geographically distant. This paper presents a multiple level-of-detail (LoD) compression strategy for 3D data based on tree-like codification structures capable of compressing a single data frame at multiple resolutions using dynamically configured parameters. The level of compression (resolution) of objects is prioritised based on: (i) placement on the scene; and (ii) the type of object. For the former, classical point cloud fitting and segmentation techniques are implemented; for the latter, user-defined prioritisation is considered. The results obtained are compared using a single LoD (whole-scene) compression technique previously proposed by the authors. Results showed a considerable improvement to the transmitted data size and updated frame rate while maintaining low distortion after decompression.
      Citation: Robotics
      PubDate: 2021-07-14
      DOI: 10.3390/robotics10030089
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 90: Nonlinear Model Predictive Horizon for
           Optimal Trajectory Generation

    • Authors: Younes Al Younes, Martin Barczyk
      First page: 90
      Abstract: This paper presents a trajectory generation method for a nonlinear system under closed-loop control (here a quadrotor drone) motivated by the Nonlinear Model Predictive Control (NMPC) method. Unlike NMPC, the proposed method employs a closed-loop system dynamics model within the optimization problem to efficiently generate reference trajectories in real time. We call this approach the Nonlinear Model Predictive Horizon (NMPH). The closed-loop model used within NMPH employs a feedback linearization control law design to decrease the nonconvexity of the optimization problem and thus achieve faster convergence. For robust trajectory planning in a dynamically changing environment, static and dynamic obstacle constraints are supported within the NMPH algorithm. Our algorithm is applied to a quadrotor system to generate optimal reference trajectories in 3D, and several simulation scenarios are provided to validate the features and evaluate the performance of the proposed methodology.
      Citation: Robotics
      PubDate: 2021-07-14
      DOI: 10.3390/robotics10030090
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 91: The Wearable Robotic Forearm: Design and
           Predictive Control of a Collaborative Supernumerary Robot

    • Authors: Vighnesh Vatsal, Guy Hoffman
      First page: 91
      Abstract: This article presents the design process of a supernumerary wearable robotic forearm (WRF), along with methods for stabilizing the robot’s end-effector using human motion prediction. The device acts as a lightweight “third arm” for the user, extending their reach during handovers and manipulation in close-range collaborative activities. It was developed iteratively, following a user-centered design process that included an online survey, contextual inquiry, and an in-person usability study. Simulations show that the WRF significantly enhances a wearer’s reachable workspace volume, while remaining within biomechanical ergonomic load limits during typical usage scenarios. While operating the device in such scenarios, the user introduces disturbances in its pose due to their body movements. We present two methods to overcome these disturbances: autoregressive (AR) time series and a recurrent neural network (RNN). These models were used for forecasting the wearer’s body movements to compensate for disturbances, with prediction horizons determined through linear system identification. The models were trained offline on a subset of the KIT Human Motion Database, and tested in five usage scenarios to keep the 3D pose of the WRF’s end-effector static. The addition of the predictive models reduced the end-effector position errors by up to 26% compared to direct feedback control.
      Citation: Robotics
      PubDate: 2021-07-16
      DOI: 10.3390/robotics10030091
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 92: Contextualizing Human—Automated Vehicle
           Interactions: A Socio-Ecological Framework

    • Authors: Lionel Peter Robert
      First page: 92
      Abstract: Automated vehicles (AVs) have given rise to a new field of study: human—automated vehicle interaction (H–AVI). Unfortunately, the H–AVI field has largely ignored the importance of context. To address this, this paper describes a socio-ecological view of H–AVI. Drawing on this view, the author briefly discusses and identifies unexplored areas. In doing so, the author draws attention to: (i) transportation infrastructure, (ii) national and regional differences, (iii) special and vulnerable populations and (iv) the impacts of multiple H–AVI types. This paper describes the challenges and opportunities in each of these areas.
      Citation: Robotics
      PubDate: 2021-07-20
      DOI: 10.3390/robotics10030092
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 93: Variational AutoEncoder to Identify Anomalous
           Data in Robots

    • Authors: Luigi Pangione, Guy Burroughes, Robert Skilton
      First page: 93
      Abstract: For robotic systems involved in challenging environments, it is crucial to be able to identify faults as early as possible. In challenging environments, it is not always possible to explore all of the fault space, thus anomalous data can act as a broader surrogate, where an anomaly may represent a fault or a predecessor to a fault. This paper proposes a method for identifying anomalous data from a robot, whilst using minimal nominal data for training. A Monte Carlo ensemble sampled Variational AutoEncoder was utilised to determine nominal and anomalous data through reconstructing live data. This was tested on simulated anomalies of real data, demonstrating that the technique is capable of reliably identifying an anomaly without any previous knowledge of the system. With the proposed system, we obtained an F1-score of 0.85 through testing.
      Citation: Robotics
      PubDate: 2021-07-21
      DOI: 10.3390/robotics10030093
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 94: A Study on the Feasibility of Robotic
           Harvesting for Chile Pepper

    • Authors: Muhammad Umar Masood, Mahdi Haghshenas-Jaryani
      First page: 94
      Abstract: This paper presents a study on the robotic harvesting of New Mexico type chile pepper, in a laboratory setting, using a five degrees of freedom (DoF) serial manipulator. The end-effector of the manipulator, a scissor-type cutting mechanism, was devised and experimentally tested in a lab setup which cuts the chile stem to detach the fruit. Through a MATLAB™-based program, the location of the chile pepper is estimated in the robot’s reference frame, using Intel RealSense Depth Camera. The accuracy of the 3D location estimation system matches the maximum accuracy claimed by the manufacturer of the hardware, with a maximum error to be in Y-axis, which is 5.7 mm. The forward and inverse kinematics are developed, and the reachable and dexterous workspaces of the robot are studied. An application-based path planning algorithm is developed to minimize the travel for a specified harvesting task. The robotic harvesting system was able to cut the chile pepper from the plant based on 3D location estimated by MATLAB™ program. On the basis of harvesting operation, on 77 chile peppers, the following harvesting indicators were achieved: localization success rate of 37.7%, detachment success rate of 65.5%, harvest success rate of 24.7%, damage rate of 6.9%, and cycle time of 7 s.
      Citation: Robotics
      PubDate: 2021-07-22
      DOI: 10.3390/robotics10030094
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 95: An Adaptive Assistance Controller to Optimize
           the Exoskeleton Contribution in Rehabilitation

    • Authors: Rezvan Nasiri, Mohammad Shushtari, Arash Arami
      First page: 95
      Abstract: In this paper, we present a novel adaptation rule to optimize the exoskeleton assistance in rehabilitation tasks. The proposed method adapts the exoskeleton contribution to user impairment severity without any prior knowledge about the user motor capacity. The proposed controller is a combination of an adaptive feedforward controller and a low gain adaptive PD controller. The PD controller guarantees the stability of the human-exoskeleton system during feedforward torque adaptation by utilizing only the human-exoskeleton joint positions as the sensory feedback for assistive torque optimization. In addition to providing a convergence proof, in order to study the performance of our method we applied it to a simplified 2-DOF model of human-arm and a generic 9-DOF model of lower limb to perform walking. In each simulated task, we implemented the impaired human torque to be insufficient for the task completion. Moreover, the scenarios that violate our convergence proof assumptions are considered. The simulation results show a converging behavior for the proposed controller; the maximum convergence time of 20 s is observed. In addition, a stable control performance that optimally supplements the remaining user motor contribution is observed; the joint angle tracking error in steady condition and its improvement compared to the start of adaptation are as follows: shoulder 0.96±2.53° (76%); elbow −0.35±0.81° (33%); hip 0.10±0.86° (38%); knee −0.19±0.67° (25%); and ankle −0.05±0.20° (60%). The presented simulation results verify the robustness of proposed adaptive method in cases that differ from our mathematical assumptions and indicate its potentials to be used in practice.
      Citation: Robotics
      PubDate: 2021-07-24
      DOI: 10.3390/robotics10030095
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 96: The WL_PCR: A Planning for Ground-to-Pole
           Transition of Wheeled-Legged Pole-Climbing Robots

    • Authors: Yankai Wang, Qiaoling Du, Tianhe Zhang, Chengze Xue
      First page: 96
      Abstract: Hybrid mobile robots with two motion modes of a wheeled vehicle and truss structure with the ability to climb poles have significant flexibility. The motion planning of this kind of robot on a pole has been widely studied, but few studies have focused on the transition of the robot from the ground to the pole. In this study, a locomotion strategy of wheeled-legged pole-climbing robots (the WL_PCR) is proposed to solve the problem of ground-to-pole transition. By analyzing the force of static and dynamic process in the ground-to-pole transition, the condition of torque provided by the gripper and moving joint is proposed. The mathematical expression of Centre of Mass (CoM) of the wheeled-legged pole-climbing robots is utilized, and the conditions for the robot to smoothly transition from the ground to the vertical pole are proposed. Finally, the feasibility of this method is proved by the simulation and experimentation of a locomotion strategy on wheeled-legged pole-climbing robots.
      Citation: Robotics
      PubDate: 2021-07-27
      DOI: 10.3390/robotics10030096
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 97: Towards the Determination of Safe Operating
           Envelopes for Autonomous UAS in Offshore Inspection Missions

    • Authors: Vincent Page, Christopher Dadswell, Matt Webster, Mike Jump, Michael Fisher
      First page: 97
      Abstract: A drive to reduce costs, carbon emissions, and the number of required personnel in the offshore energy industry has led to proposals for the increased use of autonomous/robotic systems for many maintenance tasks. There are questions over how such missions can be shown to be safe. A corollary exists in the manned aviation world for helicopter–ship operations where a test pilot attempts to operate from a ship under a range of wind conditions and provides subjective feedback on the level of difficulty encountered. This defines the ship–helicopter operating limit envelope (SHOL). Due to the cost of creating a SHOL there has been considerable research activity to demonstrate that much of this process can be performed virtually. Unmanned vehicles, however, have no test pilot to provide feedback. This paper therefore explores the possibility of adapting manned simulation techniques to the unmanned world to demonstrate that a mission is safe. Through flight modelling and simulation techniques it is shown that operating envelopes can be created for an oil rig inspection task and that, by using variable performance specifications, these can be tailored to suit the level of acceptable risk. The operating envelopes produced provide condensed and intelligible information regarding the environmental conditions under which the UAS can perform the task.
      Citation: Robotics
      PubDate: 2021-07-28
      DOI: 10.3390/robotics10030097
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 98: Self-Disclosure to a Robot: Only for Those
           Who Suffer the Most

    • Authors: Yunfei (Euphie) Duan, Myung (Ji) Yoon, Zhixuan (Edison) Liang, Johan Ferdinand Hoorn
      First page: 98
      Abstract: Social robots may become an innovative means to improve the well-being of individuals. Earlier research has shown that people easily self-disclose to a social robot, even in cases where it was unintended by the designers. We report on an experiment considering self-disclosing in a diary journal or to a social robot after negative mood induction. An off-the-shelf robot was complemented with our in-house developed AI chatbot, which could talk about ‘hot topics’ after training it with thousands of entries on a complaint website. We found that people who felt strongly negative after being exposed to shocking video footage benefited the most from talking to our robot, rather than writing down their feelings. For people less affected by the treatment, a confidential robot chat or writing a journal page did not differ significantly. We discuss emotion theory in relation to robotics and possibilities for an application in design (the emoji-enriched ‘talking stress ball’). We also underline the importance of otherwise disregarded outliers in a data set of therapeutic nature.
      Citation: Robotics
      PubDate: 2021-07-29
      DOI: 10.3390/robotics10030098
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 99: Kinematic Synthesis and Analysis of the
           RoboMech Class Parallel Manipulator with Two Grippers

    • Authors: Zhumadil Baigunchekov, Med Amine Laribi, Azamat Mustafa, Abzal Kassinov
      First page: 99
      Abstract: In this paper, methods of kinematic synthesis and analysis of the RoboMech class parallel manipulator (PM) with two grippers (end effectors) are presented. This PM is formed by connecting two output objects (grippers) with a base using two passive and one negative closing kinematic chains (CKCs). A PM with two end effectors can be used for reloading operations of stamped products between two adjacent main technologies in a cold stamping line. Passive CKCs represent two serial manipulators with two degrees of freedom, and negative CKC is a three-joined link with three negative degrees of freedom. A negative CKC imposes three geometric constraints on the movements of the two output objects. Geometric parameters of the negative CKC are determined on the basis of the problems of the Chebyshev and least-square approximations. Problems of positions and analogues of velocities and accelerations of the PM with two end effectors have been solved.
      Citation: Robotics
      PubDate: 2021-08-03
      DOI: 10.3390/robotics10030099
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 100: Trends in the Control of Hexapod Robots: A

    • Authors: Joana Coelho, Fernando Ribeiro, Bruno Dias, Gil Lopes, Paulo Flores
      First page: 100
      Abstract: The static stability of hexapods motivates their design for tasks in which stable locomotion is required, such as navigation across complex environments. This task is of high interest due to the possibility of replacing human beings in exploration, surveillance and rescue missions. For this application, the control system must adapt the actuation of the limbs according to their surroundings to ensure that the hexapod does not tumble during locomotion. The most traditional approach considers their limbs as robotic manipulators and relies on mechanical models to actuate them. However, the increasing interest in model-free models for the control of these systems has led to the design of novel solutions. Through a systematic literature review, this paper intends to overview the trends in this field of research and determine in which stage the design of autonomous and adaptable controllers for hexapods is.
      Citation: Robotics
      PubDate: 2021-08-04
      DOI: 10.3390/robotics10030100
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 101: Multidirectional Overground Robotic Training
           Leads to Improvements in Balance in Older Adults

    • Authors: Lara A. Thompson, Mehdi Badache, Joao Augusto Renno Brusamolin, Marzieh Savadkoohi, Jelani Guise, Gabriel Velluto de Paiva, Pius Suh, Pablo Sanchez Guerrero, Devdas Shetty
      First page: 101
      Abstract: For the rapidly growing aging demographic worldwide, robotic training methods could be impactful towards improving balance critical for everyday life. Here, we investigated the hypothesis that non-bodyweight supportive (nBWS) overground robotic balance training would lead to improvements in balance performance and balance confidence in older adults. Sixteen healthy older participants (69.7 ± 6.7 years old) were trained while donning a harness from a distinctive NaviGAITor robotic system. A control group of 11 healthy participants (68.7 ± 5.0 years old) underwent the same training but without the robotic system. Training included 6 weeks of standing and walking tasks while modifying: (1) sensory information (i.e., with and without vision (eyes-open/closed), with more and fewer support surface cues (hard or foam surfaces)) and (2) base-of-support (wide, tandem and single-leg standing exercises). Prior to and post-training, balance ability and balance confidence were assessed via the balance error scoring system (BESS) and the Activities specific Balance Confidence (ABC) scale, respectively. Encouragingly, results showed that balance ability improved (i.e., BESS errors significantly decreased), particularly in the nBWS group, across nearly all test conditions. This result serves as an indication that robotic training has an impact on improving balance for healthy aging individuals.
      Citation: Robotics
      PubDate: 2021-08-06
      DOI: 10.3390/robotics10030101
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 102: Paquitop.arm, a Mobile Manipulator for
           Assessing Emerging Challenges in the COVID-19 Pandemic Scenario

    • Authors: Giovanni Colucci, Luigi Tagliavini, Luca Carbonari, Paride Cavallone, Andrea Botta, Giuseppe Quaglia
      First page: 102
      Abstract: The use of automation and robotics technologies for caregiving and assistance has become a very interesting research topic in the field of robotics. The spread of COVID-19 has highlighted the importance of social distancing in hospitals and health centers, and collaborative robotics can bring substantial improvements in terms of sparing health workers basic operations. Thus, researchers from Politecnico di Torino are working on Paquitop.arm, a mobile robot for assistive tasks. The purpose of this paper is to present a system composed of an omnidirectional mobile platform, a 6 DOF robot arm, and a depth camera. Task-oriented considerations are made to estimate a set of mounting parameters that represents a trade-off between the exploitation of the robot arm workspace and the compactness of the entire system. To this end, dexterity and force transmission indexes are introduced to study both the kinematic and the static behavior of the manipulator as a function of the mounting parameters. Finally, to avoid singularities during the execution of the task, the platform approach to the task workspaces is studied.
      Citation: Robotics
      PubDate: 2021-08-14
      DOI: 10.3390/robotics10030102
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 103: A Case Study on Improving the Software
           Dependability of a ROS Path Planner for Steep Slope Vineyards

    • Authors: Luís Carlos Santos, André Santos, Filipe Neves Santos, António Valente
      First page: 103
      Abstract: Software for robotic systems is becoming progressively more complex despite the existence of established software ecosystems like ROS, as the problems we delegate to robots become more and more challenging. Ensuring that the software works as intended is a crucial (but not trivial) task, although proper quality assurance processes are rarely seen in the open-source robotics community. This paper explains how we analyzed and improved a specialized path planner for steep-slope vineyards regarding its software dependability. The analysis revealed previously unknown bugs in the system, with a relatively low property specification effort. We argue that the benefits of similar quality assurance processes far outweigh the costs and should be more widespread in the robotics domain.
      Citation: Robotics
      PubDate: 2021-08-26
      DOI: 10.3390/robotics10030103
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 104: Cylindabot: Transformable Wheg Robot
           Traversing Stepped and Sloped Environments

    • Authors: Robert Woolley, Jon Timmis, Andy M. Tyrrell
      First page: 104
      Abstract: The ability of an autonomous robot to adapt to different terrain affords the flexibility to move successfully in a range of environments. This paper proposes the Cylindabot, a transformable Wheg robot that can move with two large wheels, each of which can rotate out, producing three legs. This ability to change its mode of locomotion allows for specialised performance. The Cylindabot has been tested in simulation and on a physical robot on steps and slopes as an indication of its efficacy in different environments. These experiments show that such robots are capable of climbing up to a 32 degree slope and a step 1.43 times their initial height. Theoretical limits are devised that match the results, and a comparison with existing Wheg platforms is made.
      Citation: Robotics
      PubDate: 2021-08-30
      DOI: 10.3390/robotics10030104
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 105: Reinforcement Learning for Pick and Place
           Operations in Robotics: A Survey

    • Authors: Andrew Lobbezoo, Yanjun Qian, Hyock-Ju Kwon
      First page: 105
      Abstract: The field of robotics has been rapidly developing in recent years, and the work related to training robotic agents with reinforcement learning has been a major focus of research. This survey reviews the application of reinforcement learning for pick-and-place operations, a task that a logistics robot can be trained to complete without support from a robotics engineer. To introduce this topic, we first review the fundamentals of reinforcement learning and various methods of policy optimization, such as value iteration and policy search. Next, factors which have an impact on the pick-and-place task, such as reward shaping, imitation learning, pose estimation, and simulation environment are examined. Following the review of the fundamentals and key factors for reinforcement learning, we present an extensive review of all methods implemented by researchers in the field to date. The strengths and weaknesses of each method from literature are discussed, and details about the contribution of each manuscript to the field are reviewed. The concluding critical discussion of the available literature, and the summary of open problems indicates that experiment validation, model generalization, and grasp pose selection are topics that require additional research.
      Citation: Robotics
      PubDate: 2021-09-13
      DOI: 10.3390/robotics10030105
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 106: Socially Assistive Robots Helping Older
           Adults through the Pandemic and Life after COVID-19

    • Authors: Cristina Getson, Goldie Nejat
      First page: 106
      Abstract: The COVID-19 pandemic has critically impacted the health and safety of the population of the world, especially the health and well-being of older adults. Socially assistive robots (SARs) have been used to help to mitigate the effects of the pandemic including loneliness and isolation, and to alleviate the workload of both formal and informal caregivers. This paper presents the first extensive survey and discussion on just how socially assistive robots have specifically helped this population, as well as the overall impact on health and the acceptance of such robots during the pandemic. The goal of this review is to answer research questions with respect to which SARs were used during the pandemic and what specific tasks they were used for, and what the enablers and barriers were to the implementation of SARs during the pandemic. We will also discuss lessons learned from their use to inform future SAR design and applications, and increase their usefulness and adoption in a post-pandemic world. More research is still needed to investigate and appreciate the user experience of older adults with SARs during the pandemic, and we aim to provide a roadmap for researchers and stakeholders.
      Citation: Robotics
      PubDate: 2021-09-13
      DOI: 10.3390/robotics10030106
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 107: Nut Unfastening by Robotic Surface

    • Authors: Alireza Rastegarpanah, Rohit Ner, Rustam Stolkin, Naresh Marturi
      First page: 107
      Abstract: In this paper, we present a novel concept and primary investigations regarding automated unfastening of hexagonal nuts by means of surface exploration with a compliant robot. In contrast to the conventional industrial approaches that rely on custom-designed motorised tools and mechanical tool changers, we propose to use robot fingers to position, grasp and unfasten unknown random-sized hexagonal nuts, which are arbitrarily positioned in the robot’s task space. Inspired by how visually impaired people handle unknown objects, in this work, we use information observed from surface exploration to devise the unfastening strategy. It combines torque monitoring with active compliance for the robot fingers to smoothly explore the object’s surface. We implement a shape estimation technique combining scaled iterative closest point and hypotrochoid approximation to estimate the location as well as contour profile of the hexagonal nut so as to accurately position the gripper fingers. We demonstrate this work in the context of dismantling an electrically driven vehicle battery pack. The experiments are conducted using a seven degrees of freedom (DoF)–compliant robot fitted with a two-finger gripper to unfasten four different sized randomly positioned hexagonal nuts. The obtained results suggest an overall exploration and unfastening success rate of 95% over an average of ten trials for each nut.
      Citation: Robotics
      PubDate: 2021-09-14
      DOI: 10.3390/robotics10030107
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 108: Engineering Interoperable, Plug-and-Play,
           Distributed, Robotic Control Systems for Futureproof Fusion Power Plants

    • Authors: Ipek Caliskanelli, Matthew Goodliffe, Craig Whiffin, Michail Xymitoulias, Edward Whittaker, Swapnil Verma, Robert Skilton
      First page: 108
      Abstract: Maintenance and inspection systems for future fusion power plants (e.g., STEP and DEMO) are expected to require the integration of hundreds of systems from multiple suppliers, with lifetime expectancies of several decades, where requirements evolve over time and obsolescence management is required. There are significant challenges associated with the integration, deployment, and maintenance of very large-scale robotic systems incorporating devices from multiple suppliers, where each may utilise bespoke, non-standardised control systems and interfaces. Additionally, the unstructured, experimental, or unknown operational conditions frequently result in new or changing system requirements, meaning extension and adaptation are necessary. Whilst existing control frameworks (e.g., ROS, OPC-UA) allow for the robust integration of complex robotic systems, they are not compatible with highly efficient maintenance and extension in the face of changing requirements and obsolescence issues over decades-long periods. We present the CorteX software framework as well as results showing its effectiveness in addressing the above issues, whilst being demonstrated through hardware that is representative of real-world fusion applications.
      Citation: Robotics
      PubDate: 2021-09-16
      DOI: 10.3390/robotics10030108
      Issue No: Vol. 10, No. 3 (2021)
  • Robotics, Vol. 10, Pages 52: Advances in Agriculture Robotics: A
           State-of-the-Art Review and Challenges Ahead

    • Authors: Luiz F. P. Oliveira, António P. Moreira, Manuel F. Silva
      First page: 52
      Abstract: The constant advances in agricultural robotics aim to overcome the challenges imposed by population growth, accelerated urbanization, high competitiveness of high-quality products, environmental preservation and a lack of qualified labor. In this sense, this review paper surveys the main existing applications of agricultural robotic systems for the execution of land preparation before planting, sowing, planting, plant treatment, harvesting, yield estimation and phenotyping. In general, all robots were evaluated according to the following criteria: its locomotion system, what is the final application, if it has sensors, robotic arm and/or computer vision algorithm, what is its development stage and which country and continent they belong. After evaluating all similar characteristics, to expose the research trends, common pitfalls and the characteristics that hinder commercial development, and discover which countries are investing into Research and Development (R&D) in these technologies for the future, four major areas that need future research work for enhancing the state of the art in smart agriculture were highlighted: locomotion systems, sensors, computer vision algorithms and communication technologies. The results of this research suggest that the investment in agricultural robotic systems allows to achieve short—harvest monitoring—and long-term objectives—yield estimation.
      Citation: Robotics
      PubDate: 2021-03-24
      DOI: 10.3390/robotics10020052
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 53: Advances in Forest Robotics: A
           State-of-the-Art Survey

    • Authors: Luiz F. P. Oliveira, António P. Moreira, Manuel F. Silva
      First page: 53
      Abstract: The development of robotic systems to operate in forest environments is of great relevance for the public and private sectors. In this sense, this article reviews several scientific papers, research projects and commercial products related to robotic applications for environmental preservation, monitoring, wildfire firefighting, inventory operations, planting, pruning and harvesting. After conducting critical analysis, the main characteristics observed were: (a) the locomotion system is directly affected by the type of environmental monitoring to be performed; (b) different reasons for pruning result in different locomotion and cutting systems; (c) each type of forest, in each season and each type of soil can directly interfere with the navigation technique used; and (d) the integration of the concept of swarm of robots with robots of different types of locomotion systems (land, air or sea) can compensate for the time of executing tasks in unstructured environments. Two major areas are proposed for future research works: Internet of Things (IoT)-based smart forest and navigation systems. It is expected that, with the various characteristics exposed in this paper, the current robotic forest systems will be improved, so that forest exploitation becomes more efficient and sustainable.
      Citation: Robotics
      PubDate: 2021-03-24
      DOI: 10.3390/robotics10020053
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 54: Human–Robot Interaction through Eye
           Tracking for Artistic Drawing

    • Authors: Lorenzo Scalera, Stefano Seriani, Paolo Gallina, Mattia Lentini, Alessandro Gasparetto
      First page: 54
      Abstract: In this paper, authors present a novel architecture for controlling an industrial robot via an eye tracking interface for artistic purposes. Humans and robots interact thanks to an acquisition system based on an eye tracker device that allows the user to control the motion of a robotic manipulator with his gaze. The feasibility of the robotic system is evaluated with experimental tests in which the robot is teleoperated to draw artistic images. The tool can be used by artists to investigate novel forms of art and by amputees or people with movement disorders or muscular paralysis, as an assistive technology for artistic drawing and painting, since, in these cases, eye motion is usually preserved.
      Citation: Robotics
      PubDate: 2021-03-26
      DOI: 10.3390/robotics10020054
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 55: Multi AGV Coordination Tolerant to
           Communication Failures

    • Authors: Diogo Matos, Pedro Costa, José Lima, Paulo Costa
      First page: 55
      Abstract: Most path planning algorithms used presently in multi-robot systems are based on offline planning. The Timed Enhanced A* (TEA*) algorithm gives the possibility of planning in real time, rather than planning in advance, by using a temporal estimation of the robot’s positions at any given time. In this article, the implementation of a control system for multi-robot applications that operate in environments where communication faults can occur and where entire sections of the environment may not have any connection to the communication network will be presented. This system uses the TEA* to plan multiple robot paths and a supervision system to control communications. The supervision system supervises the communication with the robots and checks whether the robot’s movements are synchronized. The implemented system allowed the creation and execution of paths for the robots that were both safe and kept the temporal efficiency of the TEA* algorithm. Using the Simtwo2020 simulation software, capable of simulating movement dynamics and the Lazarus development environment, it was possible to simulate the execution of several different missions by the implemented system and analyze their results.
      Citation: Robotics
      PubDate: 2021-03-27
      DOI: 10.3390/robotics10020055
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 56: An Introduction to Patterns for the Internet
           of Robotic Things in the Ambient Assisted Living Scenario

    • Authors: Bruno Andò, Luciano Cantelli, Vincenzo Catania, Ruben Crispino, Dario Calogero Guastella, Salvatore Monteleone, Giovanni Muscato
      First page: 56
      Abstract: The Internet of Things paradigm envisions the interoperation among objects, people, and their surrounding environment. In the last decade, the spread of IoT-based solutions has been supported in various domains and scenarios by academia, industry, and standards-setting organizations. The wide variety of applications and the need for a higher level of autonomy and interaction with the environment have recently led to the rise of the Internet of Robotic Things (IoRT), where smart objects become autonomous robotic systems. As mentioned in the recent literature, many of the proposed solutions in the IoT field have to tackle similar challenges regarding the management of resources, interoperation among objects, and interaction with users and the environment. Given that, the concept of the IoT pattern has recently been introduced. In software engineering, a pattern is defined as a general solution that can be applied to a class of common problems. It is a template suggesting a solution for the same problem occurring in different contexts. Similarly, an IoT pattern provides a guide to design an IoT solution with the difference that the software is not the only element involved. Starting from this idea, we propose the novel concept of the IoRT pattern. To the authors’ knowledge, this is the first attempt at pattern authoring in the Internet of Robotic Things context. We focus on pattern identification by abstracting examples also in the Ambient Assisted Living (AAL) scenario. A case study providing an implementation of the proposed patterns in the AAL context is also presented and discussed.
      Citation: Robotics
      PubDate: 2021-04-04
      DOI: 10.3390/robotics10020056
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 57: Scheduling and Path-Planning for Operator
           Oversight of Multiple Robots

    • Authors: Sebastián A. Zanlongo, Peter Dirksmeier, Philip Long, Taskin Padir, Leonardo Bobadilla
      First page: 57
      Abstract: There is a need for semi-autonomous systems capable of performing both automated tasks and supervised maneuvers. When dealing with multiple robots or robots with high complexity (such as humanoids), we face the issue of effectively coordinating operators across robots. We build on our previous work to present a methodology for designing trajectories and policies for robots such that a few operators can supervise multiple robots. Specifically, we: (1) Analyze the complexity of the problem, (2) Design a procedure for generating policies allowing operators to oversee many robots, (3) Present a method for designing policies and robot trajectories to allow operators to oversee multiple robots, and (4) Include both simulation and hardware experiments demonstrating our methodologies.
      Citation: Robotics
      PubDate: 2021-04-06
      DOI: 10.3390/robotics10020057
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 58: Particle Swarm Optimization—An Adaptation
           for the Control of Robotic Swarms

    • Authors: George Rossides, Benjamin Metcalfe, Alan Hunter
      First page: 58
      Abstract: Particle Swarm Optimization (PSO) is a numerical optimization technique based on the motion of virtual particles within a multidimensional space. The particles explore the space in an attempt to find minima or maxima to the optimization problem. The motion of the particles is linked, and the overall behavior of the particle swarm is controlled by several parameters. PSO has been proposed as a control strategy for physical swarms of robots that are localizing a source; the robots are analogous to the virtual particles. However, previous attempts to achieve this have shown that there are inherent problems. This paper addresses these problems by introducing a modified version of PSO, as well as introducing new guidelines for parameter selection. The proposed algorithm links the parameters to the velocity and acceleration of each robot, and demonstrates obstacle avoidance. Simulation results from both MATLAB and Gazebo show close agreement and demonstrate that the proposed algorithm is capable of effective control of a robotic swarm and obstacle avoidance.
      Citation: Robotics
      PubDate: 2021-04-08
      DOI: 10.3390/robotics10020058
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 59: Software Sensors for Order Tracking Applied
           to Permanent Magnet Synchronous Generator Diagnostics: A Comparative Study

    • Authors: Laurent Rambault, Abdallah Allouche, Erik Etien, Anas Sakout, Thierry Doget, Sebastien Cauet
      First page: 59
      Abstract: The paper deals with software sensors which facilitates the diagnosis of electrical machines in non-stationary operating conditions. The technique targeted is order tracking for which different techniques exist to estimate the speed and angle of rotation. However, from a methodological point of view, this paper offers a comparison of several methods in order to evaluate their performance from tests on a test bench. In addition, to perform the tests, it is necessary to initialize the different methods to make them work correctly. In particular, an identification technique is proposed as well as a way to facilitate initialization. The example of this paper is that of a synchronous generator. Angular sampling allows the spectrum to be stationary and the interpretation of a possible defect. The realization of the angular sampling and the first diagnostic elements require the knowledge of two fundamental quantities: the speed of rotation and the angular position of the shaft. The estimation of the rotation speed as well as the estimation of the angular position of the shaft are carried out from the measurement of an electric current (or three electric currents and three voltages). Four methods are proposed and evaluated to realize software sensors: identification technique, PLL (Phase Locked Loop), Concordia transform and an observer. The four methods are evaluated on measurements carried out on a test bench. The results are discussed from the diagnosis of a mechanical fault.
      Citation: Robotics
      PubDate: 2021-04-08
      DOI: 10.3390/robotics10020059
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 60: A Laser-Based Direct Cable Length Measurement
           Sensor for CDPRs

    • Authors: Christoph Martin, Marc Fabritius, Johannes T. Stoll, Andreas Pott
      First page: 60
      Abstract: Accuracy improvement is an important research topic in the field of cable-driven parallel robots (CDPRs). One reason for inaccuracies of CDPRs are deviations in the cable lengths. Such deviations can be caused by the elongation of the cable due to its elasticity or creep behavior. For most common CDPRs, the cable lengths are controlled using motor encoders of the winches, without feedback about the actual elongation of the cables. To address this problem, this paper proposes a direct cable length measurement sensor based on a laser distance sensor. We present the mechanical design, the first prototype and an experimental evaluation. As a result, the measurement principle works well and the accuracy of the measured cable lengths is within −2.32 mm to +1.86 mm compared to a range from −5.19 mm to +6.02 mm of the cable length set with the motor encoders. The standard deviation of the cable length error of the direct cable length measurement sensor is 58% lower compared to the one set with the motor encoders. Equipping all cables of the cable robot with direct cable length measurement sensors results in the possibility to correct cable length deviations and thus increase the accuracy of CDPRs. Furthermore, it enables new possibilities like the automatic recalibration of the home pose.
      Citation: Robotics
      PubDate: 2021-04-21
      DOI: 10.3390/robotics10020060
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 61: FES Cycling and Closed-Loop Feedback Control
           for Rehabilitative Human–Robot Interaction

    • Authors: Christian Cousin, Victor Duenas, Warren Dixon
      First page: 61
      Abstract: For individuals with movement impairments due to neurological injuries, rehabilitative therapies such as functional electrical stimulation (FES) and rehabilitation robots hold vast potential to improve their mobility and activities of daily living. Combining FES with rehabilitation robots results in intimately coordinated human–robot interaction. An example of such interaction is FES cycling, where motorized assistance can provide high-intensity and repetitive practice of coordinated limb motion, resulting in physiological and functional benefits. In this paper, the development of multiple FES cycling testbeds and safeguards is described, along with the switched nonlinear dynamics of the cycle–rider system. Closed-loop FES cycling control designs are described for cadence and torque tracking. For each tracking objective, the authors’ past work on robust and adaptive controllers used to compute muscle stimulation and motor current inputs is presented and discussed. Experimental results involving both able-bodied individuals and participants with neurological injuries are provided for each combination of controller and tracking objective. Trade-offs for the control algorithms are discussed based on the requirements for implementation, desired rehabilitation outcomes and resulting rider performance. Lastly, future works and the applicability of the developed methods to additional technologies including teleoperated robotics are outlined.
      Citation: Robotics
      PubDate: 2021-04-22
      DOI: 10.3390/robotics10020061
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 62: Implementation and Evaluation of a
           Semi-Autonomous Hydraulic Dual Manipulator for Cutting Pipework in
           Radiologically Active Environments

    • Authors: Stephen D. Monk, Alex Grievson, Manuel Bandala, Craig West, Allahyar Montazeri, C. James Taylor
      First page: 62
      Abstract: We describe the implementation of a bespoke two arm hydraulically actuated robotic platform which is used to semi-autonomously cut approximately 50 mm diameter pipes of three different materials: cardboard, ABS plastic and aluminium. The system is designed to be utilised within radiologically active environments where human access is limited due to dose limits and thus remote operation is greatly beneficial. The remotely located operator selects the object from an image via a bespoke algorithm featuring a COTS 3D vision system, along with the desired positions for gripping with one manipulator, and cutting with the other. A pseudo-Jacobian inverse kinematic technique and a programmable automation controller are used to achieve the appropriate joint positions within the dual arm robotic platform. In this article, we present the latest developments to the system and the lessons learnt from the new cutting experiments with a reciprocating saw. A comparison to tele-operated control and manual cutting is also made, with this technique shown to be slower than manual cutting, but faster than pure tele-operational control, where the requirements for highly trained users and operator fatigue are further deleterious factors.
      Citation: Robotics
      PubDate: 2021-04-27
      DOI: 10.3390/robotics10020062
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 63: Prototype Development of Small Mobile Robots
           for Mallard Navigation in Paddy Fields: Toward Realizing Remote Farming

    • Authors: Hirokazu Madokoro, Satoshi Yamamoto, Yo Nishimura, Stephanie Nix, Hanwool Woo, Kazuhito Sato
      First page: 63
      Abstract: This study was conducted to develop robot prototypes of three models that navigate mallards to achieve high-efficiency rice-duck farming. We examined two robotics navigation approaches based on imprinting and feeding. As the first approach, we used imprinting applied to baby mallards. They exhibited follow behavior to our first prototype after imprinting. Experimentally obtained observation results revealed the importance of providing imprinting immediately up to one week after hatching. As another approach, we used feed placed on the top of our second prototype. Experimentally obtained results showed that adult mallards exhibited wariness not only against the robot, but also against the feeder. After relieving wariness with provision of more than one week time to become accustomed, adult mallards ate feed in the box on the robot. However, they ran away immediately at a slight movement. Based on this confirmation, we developed the third prototype as an autonomous mobile robot aimed for mallard navigation in a paddy field. The body width is less than the length between rice stalks. After checking the waterproof capability of a body waterproof box, we conducted an indoor driving test for manual operation. Moreover, we conducted outdoor evaluation tests to assess running on an actual paddy field. We developed indoor and outdoor image datasets using an onboard monocular camera. For the outdoor image datasets, our segmentation method based on SegNet achieved semantic segmentation for three semantic categories. For the indoor image datasets, our prediction method based on CNN and LSTM achieved visual prediction for three motion categories.
      Citation: Robotics
      PubDate: 2021-04-27
      DOI: 10.3390/robotics10020063
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 64: Condition Assessment for Concrete Sewer Pipes
           Using Displacement Probes: A Robotic Design Case Study

    • Authors: Robert Ross, Alex Stumpf, Dean Barnett, Richard Hall
      First page: 64
      Abstract: Worldwide, millions of kilometres of sewers are constructed from concrete pipes. Unfortunately, concrete sewers are susceptible to corrosion from biogenic hydrogen sulphide, and, though they may pass visual inspection, their ability to hold together under load may be degraded. This paper presents the design of a teleoperated robot with a protractible probe, that allows an operator to apply a localised load to selected points within a concrete sewer pipe. We report findings from laboratory and field trials of our prototype, with initial results suggesting that this approach has the potential to contribute useful information to sewer maintenance planning.
      Citation: Robotics
      PubDate: 2021-04-27
      DOI: 10.3390/robotics10020064
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 65: Validating Safety in Human–Robot
           Collaboration: Standards and New Perspectives

    • Authors: Marcello Valori, Adriano Scibilia, Irene Fassi, José Saenz, Roland Behrens, Sebastian Herbster, Catherine Bidard, Eric Lucet, Alice Magisson, Leendert Schaake, Jule Bessler, Gerdienke B. Prange-Lasonder, Morten Kühnrich, Aske B. Lassen, Kurt Nielsen
      First page: 65
      Abstract: Human–robot collaboration is currently one of the frontiers of industrial robot implementation. In parallel, the use of robots and robotic devices is increasing in several fields, substituting humans in “4D”—dull, dirty, dangerous, and delicate—tasks, and such a trend is boosted by the recent need for social distancing. New challenges in safety assessment and verification arise, due to both the closer and closer human–robot interaction, common for the different application domains, and the broadening of user audience, which is now very diverse. The present paper discusses a cross-domain approach towards the definition of step-by-step validation procedures for collaborative robotic applications. To outline the context, the standardization framework is analyzed, especially from the perspective of safety testing and assessment. Afterwards, some testing procedures based on safety skills, developed within the framework of the European project COVR, are discussed and exemplary presented.
      Citation: Robotics
      PubDate: 2021-04-29
      DOI: 10.3390/robotics10020065
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 66: Unsupervised Online Grounding for Social

    • Authors: Oliver Roesler, Elahe Bagheri
      First page: 66
      Abstract: Robots that incorporate social norms in their behaviors are seen as more supportive, friendly, and understanding. Since it is impossible to manually specify the most appropriate behavior for all possible situations, robots need to be able to learn it through trial and error, by observing interactions between humans, or by utilizing theoretical knowledge available in natural language. In contrast to the former two approaches, the latter has not received much attention because understanding natural language is non-trivial and requires proper grounding mechanisms to link words to corresponding perceptual information. Previous grounding studies have mostly focused on grounding of concepts relevant to object manipulation, while grounding of more abstract concepts relevant to the learning of social norms has so far not been investigated. Therefore, this paper presents an unsupervised cross-situational learning based online grounding framework to ground emotion types, emotion intensities and genders. The proposed framework is evaluated through a simulated human–agent interaction scenario and compared to an existing unsupervised Bayesian grounding framework. The obtained results show that the proposed framework is able to ground words, including synonyms, through their corresponding perceptual features in an unsupervised and open-ended manner, while outperfoming the baseline in terms of grounding accuracy, transparency, and deployability.
      Citation: Robotics
      PubDate: 2021-04-29
      DOI: 10.3390/robotics10020066
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 67: An Overview of Verification and Validation
           Challenges for Inspection Robots

    • Authors: Michael Fisher, Rafael C. Cardoso, Emily C. Collins, Christopher Dadswell, Louise A. Dennis, Clare Dixon, Marie Farrell, Angelo Ferrando, Xiaowei Huang, Mike Jump, Georgios Kourtis, Alexei Lisitsa, Matt Luckcuck, Shan Luo, Vincent Page, Fabio Papacchini, Matt Webster
      First page: 67
      Abstract: The advent of sophisticated robotics and AI technology makes sending humans into hazardous and distant environments to carry out inspections increasingly avoidable. Being able to send a robot, rather than a human, into a nuclear facility or deep space is very appealing. However, building these robotic systems is just the start and we still need to carry out a range of verification and validation tasks to ensure that the systems to be deployed are as safe and reliable as possible. Based on our experience across three research and innovation hubs within the UK’s “Robots for a Safer World” programme, we present an overview of the relevant techniques and challenges in this area. As the hubs are active across nuclear, offshore, and space environments, this gives a breadth of issues common to many inspection robots.
      Citation: Robotics
      PubDate: 2021-04-29
      DOI: 10.3390/robotics10020067
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 68: GazeEMD: Detecting Visual Intention in
           Gaze-Based Human-Robot Interaction

    • Authors: Lei Shi, Cosmin Copot, Steve Vanlanduit
      First page: 68
      Abstract: In gaze-based Human-Robot Interaction (HRI), it is important to determine human visual intention for interacting with robots. One typical HRI interaction scenario is that a human selects an object by gaze and a robotic manipulator will pick up the object. In this work, we propose an approach, GazeEMD, that can be used to detect whether a human is looking at an object for HRI application. We use Earth Mover’s Distance (EMD) to measure the similarity between the hypothetical gazes at objects and the actual gazes. Then, the similarity score is used to determine if the human visual intention is on the object. We compare our approach with a fixation-based method and HitScan with a run length in the scenario of selecting daily objects by gaze. Our experimental results indicate that the GazeEMD approach has higher accuracy and is more robust to noises than the other approaches. Hence, the users can lessen cognitive load by using our approach in the real-world HRI scenario.
      Citation: Robotics
      PubDate: 2021-04-30
      DOI: 10.3390/robotics10020068
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 69: Mechanical Behaviour of Large Strain
           Capacitive Sensor with Barium Titanate Ecoflex Composite Used to Detect
           Human Motion

    • Authors: Eshwar Reddy Cholleti, Jonathan Stringer, Piaras Kelly, Chris Bowen, Kean Aw
      First page: 69
      Abstract: In this paper, the effect of strain rate on the output signal of highly stretchable interdigitated capacitive (IDC) strain sensors is studied. IDC sensors fabricated with pristine Ecoflex and a composite based on 40 wt% of 200 nm barium titanate (BTO) dispersed in a silicone elastomer (Ecoflex 00-30TM) were subjected to 1000 stretch and relax cycles to study the effect of dynamic loading conditions on the output signal of the IDC sensor. It was observed that the strain rate has no effect on the output signal of IDC sensor. To study the non-linear elastic behaviour of pristine Ecoflex and composites based on 10, 20, 30, 40 wt% of 200 nm BTO filler dispersed in a silicone elastomer, we conducted uniaxial tensile testing to failure at strain rates of ~5, ~50, and ~500 mm/min. An Ogden second-order model was used to fit the uniaxial tensile test data to understand the non-linearity in the stress-strain responses of BTO-Ecoflex composite at different strain rates. The decrease in Ogden parameters (α1 and α2) indicates the decrease in non-linearity of the stress-strain response of the composite with an increase in filler loading. Scanning electronic microscopy analysis was performed on the cryo-fractured pristine Ecoflex and 10, 20, 30, and 40 wt% of BTO-Ecoflex composites, where it was found that 200 nm BTO is more uniformly distributed in Ecoflex at a higher filler loading levels (40 wt% 200 nm BTO). Therefore, an IDC sensor was fabricated based on a 40 wt% 200 nm BTO-Ecoflex composite and mounted on an elastic elbow sleeve with supporting electronics, and successfully functioned as a reliable and robust flexible sensor, demonstrating an application to measure the bending angle of an elbow at slow and fast movement of the arm. A linear relationship with respect to the elbow bending angle was observed between the IDC sensor output signal under a 50% strain and the deflection of the elbow of hand indicating its potential as a stretchable, flexible, and wearable sensor.
      Citation: Robotics
      PubDate: 2021-05-04
      DOI: 10.3390/robotics10020069
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 70: Dynamic Modeling of Planar Multi-Link
           Flexible Manipulators

    • Authors: Dipendra Subedi, Ilya Tyapin, Geir Hovland
      First page: 70
      Abstract: A closed-form dynamic model of the planar multi-link flexible manipulator is presented. The assumed modes method is used with the Lagrangian formulation to obtain the dynamic equations of motion. Explicit equations of motion are derived for a three-link case assuming two modes of vibration for each link. The eigenvalue problem associated with the mass boundary conditions, which changes with the robot configuration and payload, is discussed. The time-domain simulation results and frequency-domain analysis of the dynamic model are presented to show the validity of the theoretical derivation.
      Citation: Robotics
      PubDate: 2021-05-11
      DOI: 10.3390/robotics10020070
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 71: Multirobot Confidence and Behavior Modeling:
           An Evaluation of Semiautonomous Task Performance and Efficiency

    • Authors: Nathan Lucas, Abhilash Pandya
      First page: 71
      Abstract: There is considerable interest in multirobot systems capable of performing spatially distributed, hazardous, and complex tasks as a team leveraging the unique abilities of humans and automated machines working alongside each other. The limitations of human perception and cognition affect operators’ ability to integrate information from multiple mobile robots, switch between their spatial frames of reference, and divide attention among many sensory inputs and command outputs. Automation is necessary to help the operator manage increasing demands as the number of robots (and humans) scales up. However, more automation does not necessarily equate to better performance. A generalized robot confidence model was developed, which transforms key operator attention indicators to a robot confidence value for each robot to enable the robots’ adaptive behaviors. This model was implemented in a multirobot test platform with the operator commanding robot trajectories using a computer mouse and an eye tracker providing gaze data used to estimate dynamic operator attention. The human-attention-based robot confidence model dynamically adapted the behavior of individual robots in response to operator attention. The model was successfully evaluated to reveal evidence linking average robot confidence to multirobot search task performance and efficiency. The contributions of this work provide essential steps toward effective human operation of multiple unmanned vehicles to perform spatially distributed and hazardous tasks in complex environments for space exploration, defense, homeland security, search and rescue, and other real-world applications.
      Citation: Robotics
      PubDate: 2021-05-17
      DOI: 10.3390/robotics10020071
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 72: A* Based Routing and Scheduling Modules for
           Multiple AGVs in an Industrial Scenario

    • Authors: Joana Santos, Paulo M. Rebelo, Luis F. Rocha, Pedro Costa, Germano Veiga
      First page: 72
      Abstract: A multi-AGV based logistic system is typically associated with two fundamental problems, critical for its overall performance: the AGV’s route planning for collision and deadlock avoidance; and the task scheduling to determine which vehicle should transport which load. Several heuristic functions can be used according to the application. This paper proposes a time-based algorithm to dynamically control a fleet of Autonomous Guided Vehicles (AGVs) in an automatic warehouse scenario. Our approach includes a routing algorithm based on the A* heuristic search (TEA*—Time Enhanced A*) to generate free-collisions paths and a scheduling module to improve the results of the routing algorithm. These modules work cooperatively to provide an efficient task execution time considering as basis the routing algorithm information. Simulation experiments are presented using a typical industrial layout for 10 and 20 AGVs. Moreover, a comparison with an alternative approach from the state-of-the-art is also presented.
      Citation: Robotics
      PubDate: 2021-05-19
      DOI: 10.3390/robotics10020072
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 73: A Collision Avoidance Method Based on Deep
           Reinforcement Learning

    • Authors: Shumin Feng, Bijo Sebastian, Pinhas Ben-Tzvi
      First page: 73
      Abstract: This paper set out to investigate the usefulness of solving collision avoidance problems with the help of deep reinforcement learning in an unknown environment, especially in compact spaces, such as a narrow corridor. This research aims to determine whether a deep reinforcement learning-based collision avoidance method is superior to the traditional methods, such as potential field-based methods and dynamic window approach. Besides, the proposed obstacle avoidance method was developed as one of the capabilities to enable each robot in a novel robotic system, namely the Self-reconfigurable and Transformable Omni-Directional Robotic Modules (STORM), to navigate intelligently and safely in an unknown environment. A well-conceived hardware and software architecture with features that enable further expansion and parallel development designed for the ongoing STORM projects is also presented in this work. A virtual STORM module with skid-steer kinematics was simulated in Gazebo to reduce the gap between the simulations and the real-world implementations. Moreover, comparisons among multiple training runs of the neural networks with different parameters related to balance the exploitation and exploration during the training process, as well as tests and experiments conducted in both simulation and real-world, are presented in detail. Directions for future research are also provided in the paper.
      Citation: Robotics
      PubDate: 2021-05-19
      DOI: 10.3390/robotics10020073
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 74: Design of PEIS: A Low-Cost Pipe Inspector

    • Authors: Mario Salvatore, Alessio Galloro, Leonardo Muzzi, Giovanni Pullano, Péter Odry, Giuseppe Carbone
      First page: 74
      Abstract: This paper outlines the design of a novel mechatronic system for semi-automatic inspection and white-water in-pipe obstruction removals without the need for destructive methods or specialized manpower. The device is characterized by a lightweight structure and high transportability. It is composed by a front, a rear and a central module that realize the worm-like locomotion of the robot with a specifically designed driving mechanism for the straight motion of the robot along the pipeline. The proposed mechatronic system is easily adaptable to pipes of various sizes. Each module is equipped with a motor that actuates three slider-crank-based mechanisms. The central module incorporates a length-varying mechanism that allows forward and backward locomotion. The device is equipped with specific low-cost sensors that allow an operator to monitor the device and locate an obstruction in real time. The movement of the device can be automatic or controlled manually by using a specific user-friendly control board and a laptop. Preliminary laboratory tests are reported to demonstrate the engineering feasibility and effectiveness of the proposed design, which is currently under patenting.
      Citation: Robotics
      PubDate: 2021-05-19
      DOI: 10.3390/robotics10020074
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 75: Coordination of Multiple Robotic Vehicles in
           Obstacle-Cluttered Environments

    • Authors: Charalampos P. Bechlioulis, Panagiotis Vlantis, Kostas J. Kyriakopoulos
      First page: 75
      Abstract: In this work, we consider the motion control problem for a platoon of unicycle robots operating within an obstacle-cluttered workspace. Each robot is equipped with a proximity sensor that allows it to perceive nearby obstacles as well as a camera to obtain its relative position with respect to its preceding robot. Additionally, no robot other than the leader of the team is able to localize itself within the workspace and no centralized communication network exists, i.e., explicit information exchange between the agents is unavailable. To tackle this problem, we adopt a leader–follower architecture and propose a novel, decentralized control law for each robot-follower, based on the Prescribed Performance Control method, which guarantees collision-free tracking and visual connectivity maintenance by ensuring that each follower maintains its predecessor within its camera field of view while keeping static obstacles out of the line of sight for all time. Finally, we verify the efficacy of the proposed control scheme through extensive simulations.
      Citation: Robotics
      PubDate: 2021-05-22
      DOI: 10.3390/robotics10020075
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 76: Nonlinear Robust Control of a New
           Reconfigurable Unmanned Aerial Vehicle

    • Authors: Saddam Hocine Derrouaoui, Yasser Bouzid, Mohamed Guiatni
      First page: 76
      Abstract: In this paper, a nonlinear robust Fast Terminal Sliding Mode Controller (FTSMC) is designed to control and stabilize a new reconfigurable Unmanned Aerial Vehicle (UAV) in the presence of uncertain and variable parameters. The studied UAV is an over-actuated system due the number of actuator control inputs. It can modify the length and the angles between its four arms in different ways, which result an important variation in its Center of Gravity (CoG), inertia, and control matrix. The proposed FTSMC offers many advantages such as, reaching the desired states in a finite-time unlike the conventional sliding mode, robustness vis-a-vis uncertain and unknown parameters, fast convergence towards the sliding surface, high accuracy and reducing the chattering phenomena. Furthermore, the closed-loop stability of the this UAV is ensured by the Lyapunov theory. The eight actuators used to rotate and extend the UAV arms are controlled by simple Proportional Integral Derivative (PID) controllers. Lastly, the robustness and efficiency of the proposed controller are evaluated through a flight scenario, where the UAV geometric parameters are variable over time.
      Citation: Robotics
      PubDate: 2021-05-23
      DOI: 10.3390/robotics10020076
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 77: Trajectory Extrapolation for Manual Robot
           Remote Welding

    • Authors: Lucas Christoph Ebel, Jochen Maaß, Patrick Zuther, Shahram Sheikhi
      First page: 77
      Abstract: This article describes an algorithm for the online extrapolation of hand-motion during remote welding. The aim is to overcome the spatial limitations of the human welder’s arms in order to cover a larger workspace with a continuous weld seam and to substantially relieve the welder from strain and fatigue. Depending on the sampled hand-motion data, an extrapolation of the given motion patterns is achieved by decomposing the input signals in a linear direction and a periodic motion component. An approach to efficiently determine the periodicity using a sampled autocorrelation function and the subsequent application of parameter identification using a spline function are presented in this paper. The proposed approach is able to resemble all practically relevant motion patterns and has been validated successfully on a remote welding system with limited input space and audio-visual feedback by an experienced welder.
      Citation: Robotics
      PubDate: 2021-05-23
      DOI: 10.3390/robotics10020077
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 78: Robotic Exploration of an Unknown Nuclear
           Environment Using Radiation Informed Autonomous Navigation

    • Authors: Keir Groves, Emili Hernandez, Andrew West, Thomas Wright, Barry Lennox
      First page: 78
      Abstract: This paper describes a novel autonomous ground vehicle that is designed for exploring unknown environments which contain sources of ionising radiation, such as might be found in a nuclear disaster site or a legacy nuclear facility. While exploring the environment, it is important that the robot avoids radiation hot spots to minimise breakdowns. Broken down robots present a real problem: they not only cause the mission to fail but they can block access routes for future missions. Until now, such robots have had no autonomous gamma radiation avoidance capabilities. New software algorithms are presented that allow radiation measurements to be converted into a format in which they can be integrated into the robot’s navigation system so that it can actively avoid receiving a high radiation dose during a mission. An unmanned ground vehicle was fitted with a gamma radiation detector and an autonomous navigation package that included the new radiation avoidance software. The full system was evaluated experimentally in a complex semi-structured environment that contained two radiation sources. In the experiment, the robot successfully identified both sources and avoided areas that were found to have high levels of radiation while navigating between user defined waypoints. This advancement in the state-of-the-art has the potential to deliver real benefit to the nuclear industry, in terms of both increased chance of mission success and reduction of the reliance on human operatives to perform tasks in dangerous radiation environments.
      Citation: Robotics
      PubDate: 2021-05-24
      DOI: 10.3390/robotics10020078
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 79: The Operation of UAV Propulsion Motors in the
           Presence of High External Magnetic Fields

    • Authors: Mohammad Heggo, Anees Mohammed, Juan Melecio, Khristopher Kabbabe, Paul Tuohy, Simon Watson, Sinisa Durovic
      First page: 79
      Abstract: The operation and maintenance of converter stations (also known as valve halls) in high voltage DC (HVDC) grids is a key element in long-term, reliable and stable operation, especially in inherently adverse offshore environments. However, the nature of the electromagnetic field environment inside HVDC valve halls presents a challenge for the operation of traditional off-shelf inspection robots. In this paper, the impact of the external magnetic field on the operation of an inspection UAV’s propulsion motors is assessed. An experimental method is proposed to simulate the maximum magnetic field interference to off-shelf UAV motors, which can be used to identify their suitability for use in HVDC valve halls inspection robots. The paper’s experimental results compare the performance of direct torque control and field-oriented control algorithms for propulsion motors under the influence of external magnetic flux. Under the influence of a 177 mT external magnetic field, it was found that using direct torque control, the motor rotational velocity steady-state error was up to 55%. With field-oriented control, the steady-state error was 0%, however the peak-to-peak current draw increased by up to 567%.
      Citation: Robotics
      PubDate: 2021-06-09
      DOI: 10.3390/robotics10020079
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 80: A Method for Health Indicator Evaluation for
           Condition Monitoring of Industrial Robot Gears

    • Authors: Corbinian Nentwich, Gunther Reinhart
      First page: 80
      Abstract: Condition monitoring of industrial robots has the potential to decrease downtimes in highly automated production systems. In this context, we propose a new method to evaluate health indicators for this application and suggest a new health indicator (HI) based on vibration data measurements, Short-time Fourier transform and Z-scores. By executing the method, we find that the proposed health indicator can detect varying faults better, has lower temperature sensitivity and works better in instationary velocity regimes compared to several state-of-the-art HIs. A discussion of the validity of the results concludes our contribution.
      Citation: Robotics
      PubDate: 2021-06-09
      DOI: 10.3390/robotics10020080
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 81: On the Modelling of Tethered Mobile Robots as
           Redundant Manipulators

    • Authors: Matteo Caruso, Paolo Gallina, Stefano Seriani
      First page: 81
      Abstract: Controlling a chain of tethered mobile robots (TMRs) can be a challenging task. This kind of system can be considered kinematically as an open-chain robotic arm where the mobile robots are considered as a revolute joint and the tether is considered as a variable length link, using a prismatic joint. Thus, the TMRs problem is decoupled into two parallel problems: the equivalent robotic manipulator control and the tether shape computation. Kinematic redundancy is exploited in order to coordinate the motion of all mobile robots forming the chain, expressing the constraints acting on the mobile robots as secondary tasks for the equivalent robotic arm. Implementation in the Gazebo simulation environment shows that the methodology is capable of controlling the chain of TMRs in cluttered environments.
      Citation: Robotics
      PubDate: 2021-06-12
      DOI: 10.3390/robotics10020081
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 82: Semi-Autonomous Behaviour Tree-Based
           Framework for Sorting Electric Vehicle Batteries Components

    • Authors: Alireza Rastegarpanah, Hector Cruz Gonzalez, Rustam Stolkin
      First page: 82
      Abstract: The process of recycling electric vehicle (EV) batteries currently represents a significant challenge to the waste management automation industry. One example of it is the necessity of removing and sorting dismantled components from EV battery pack. This paper proposes a novel framework to semi-automate the process of removing and sorting different objects from an EV battery pack using a mobile manipulator. The work exploits the Behaviour Trees model for cognitive task execution and monitoring, which links different robot capabilities such as navigation, object tracking and motion planning in a modular fashion. The framework was tested in simulation, in both static and dynamic environments, and it was evaluated based on task time and the number of objects that the robot successfully placed in the respective containers. Results suggested that the robot’s success rate in accomplishing the task of sorting the battery components was 95% and 82% in static and dynamic environments, respectively.
      Citation: Robotics
      PubDate: 2021-06-17
      DOI: 10.3390/robotics10020082
      Issue No: Vol. 10, No. 2 (2021)
  • Robotics, Vol. 10, Pages 31: Inverse and Forward Kinematic Analysis of a
           6-DOF Parallel Manipulator Utilizing a Circular Guide

    • Authors: Alexey Fomin, Anton Antonov, Victor Glazunov, Yuri Rodionov
      First page: 31
      Abstract: The proposed study focuses on the inverse and forward kinematic analysis of a novel 6-DOF parallel manipulator with a circular guide. In comparison with the known schemes of such manipulators, the structure of the proposed one excludes the collision of carriages when they move along the circular guide. This is achieved by using cranks (links that provide an unlimited rotational angle) in the manipulator kinematic chains. In this case, all drives stay fixed on the base. The kinematic analysis provides analytical relationships between the end-effector coordinates and six controlled movements in drives (driven coordinates). Examples demonstrate the implementation of the suggested algorithms. For the inverse kinematics, the solution is found given the position and orientation of the end-effector. For the forward kinematics, various assembly modes of the manipulator are obtained for the same given values of the driven coordinates. The study also discusses how to choose the links lengths to maximize the rotational capabilities of the end-effector and provides a calculation of such capabilities for the chosen manipulator design.
      Citation: Robotics
      PubDate: 2021-02-07
      DOI: 10.3390/robotics10010031
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 32: Adaptive Position/Force Control of a Robotic
           Manipulator in Contact with a Flexible and Uncertain Environment

    • Authors: Piotr Gierlak
      First page: 32
      Abstract: The present paper concerns the synthesis of robot movement control systems in the cases of disturbances of natural position constraints, which are the result of surface susceptibility and inaccuracies in its description. The study contains the synthesis of control laws, in which the knowledge of parameters of the susceptible environment is not required, and which guarantee stability of the system in the case of an inaccurately described contact surface. The novelty of the presented solution is based on introducing an additional module to the control law in directions normal to the interaction surface, which allows for a fluent change of control strategy in the case of occurrence of distortions in the surface. An additional module in the control law is perceived as a virtual viscotic resistance force and resilient environment acting upon the robot. This interpretation facilitates intuitive selection of amplifications and allows for foreseeing the behavior of the system when disturbances occur. Introducing reactions of virtual constraints provides automatic adjustment of the robot interaction force with the susceptible environment, minimizing the impact of geometric inaccuracy of the environment.
      Citation: Robotics
      PubDate: 2021-02-12
      DOI: 10.3390/robotics10010032
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 33: Impact of Cycle Time and Payload of an
           Industrial Robot on Resource Efficiency

    • Authors: Florian Stuhlenmiller, Steffi Weyand, Jens Jungblut, Liselotte Schebek, Debora Clever, Stephan Rinderknecht
      First page: 33
      Abstract: Modern industry benefits from the automation capabilities and flexibility of robots. Consequently, the performance depends on the individual task, robot and trajectory, while application periods of several years lead to a significant impact of the use phase on the resource efficiency. In this work, simulation models predicting a robot’s energy consumption are extended by an estimation of the reliability, enabling the consideration of maintenance to enhance the assessment of the application’s life cycle costs. Furthermore, a life cycle assessment yields the greenhouse gas emissions for the individual application. Potential benefits of the combination of motion simulation and cost analysis are highlighted by the application to an exemplary system. For the selected application, the consumed energy has a distinct impact on greenhouse gas emissions, while acquisition costs govern life cycle costs. Low cycle times result in reduced costs per workpiece, however, for short cycle times and higher payloads, the probability of required spare parts distinctly increases for two critical robotic joints. Hence, the analysis of energy consumption and reliability, in combination with maintenance, life cycle costing and life cycle assessment, can provide additional information to improve the resource efficiency.
      Citation: Robotics
      PubDate: 2021-02-12
      DOI: 10.3390/robotics10010033
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 34: Time Coordination and Collision Avoidance
           Using Leader-Follower Strategies in Multi-Vehicle Missions

    • Authors: Camilla Tabasso, Venanzio Cichella, Syed Bilal Mehdi, Thiago Marinho, Naira Hovakimyan
      First page: 34
      Abstract: In recent years, the increasing popularity of multi-vehicle missions has been accompanied by a growing interest in the development of control strategies to ensure safety in these scenarios. In this work, we propose a control framework for coordination and collision avoidance in cooperative multi-vehicle missions based on a speed adjustment approach. The overall problem is decoupled in a coordination problem, in order to ensure coordination and inter-vehicle safety among the agents, and a collision-avoidance problem to guarantee the avoidance of non-cooperative moving obstacles. We model the network over which the cooperative vehicles communicate using tools from graph theory, and take communication losses and time delays into account. Finally, through a rigorous Lyapunov analysis, we provide performance bounds and demonstrate the efficacy of the algorithms with numerical and experimental results.
      Citation: Robotics
      PubDate: 2021-02-13
      DOI: 10.3390/robotics10010034
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 35: Experimental Investigation of a Cable Robot
           Recovery Strategy

    • Authors: Giovanni Boschetti, Riccardo Minto, Alberto Trevisani
      First page: 35
      Abstract: Developing an emergency procedure for cable-driven parallel robots is not a trivial process, since it is not possible to halt the end-effector by quickly braking the actuators as in rigid-link manipulators. For this reason, the cable robot recovery strategy is an important topic of research, and the literature provides several approaches. However, the computational efficiency of the recovery algorithm is fundamental for real-time applications. Thus, this paper presents a recovery strategy adopted in an experimental setup consisting of a three degrees-of-freedom (3-DOF) suspended cable robot controlled by an industrial PC. The presentation of the used control system lists the industrial-grade components installed, further highlighting the industrial implication of the work. Lastly, the experimental validation of the recovery strategy proves the effectiveness of the work.
      Citation: Robotics
      PubDate: 2021-02-16
      DOI: 10.3390/robotics10010035
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 36: Dynamic Parameter Identification of a
           Pointing Mechanism Considering the Joint Clearance

    • Authors: Jing Sun, Xueyan Han, Tong Li, Shihua Li
      First page: 36
      Abstract: The clearance of the revolute joint influences the accuracy of dynamic parameter identification. In order to address this problem, a method for dynamic parameter identification of an X–Y pointing mechanism while considering the clearance of the revolute joint is proposed in this paper. Firstly, the nonlinear dynamic model of the pointing mechanism was established based on a modified contact model, which took the effect of the asperity of contact surface on joint clearance into consideration. Secondly, with the aim of achieving the anti-interference incentive trajectory, the trajectory was optimized according to the condition number of the observation matrix and the driving functions of activate joints that could be obtained. Thirdly, dynamic simulation was conducted through Adams software, and clearance was involved in the simulation model. Finally, the dynamic parameter identification of the pointing mechanism was conducted based on an artificial bee colony (ABC) algorithm. The identification result that considered joint clearance was compared with that which did not consider joint clearance. The results showed that the accuracy of the dynamic parameter identification was improved when the clearance was taken into consideration. This study provides a theoretical basis for the improvement of dynamic parameter identification accuracy.
      Citation: Robotics
      PubDate: 2021-02-20
      DOI: 10.3390/robotics10010036
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 37: Visual Intelligence: Prediction of
           Unintentional Surgical-Tool-Induced Bleeding during Robotic and
           Laparoscopic Surgery

    • Authors: Mostafa Daneshgar Rahbar, Hao Ying, Abhilash Pandya
      First page: 37
      Abstract: Unintentional vascular damage can result from a surgical instrument’s abrupt movements during minimally invasive surgery (laparoscopic or robotic). A novel real-time image processing algorithm based on local entropy is proposed that can detect abrupt movements of surgical instruments and predict bleeding occurrence. The uniform nature of the texture of surgical tools is utilized to segment the tools from the background. By comparing changes in entropy over time, the algorithm determines when the surgical instruments are moved abruptly. We tested the algorithm using 17 videos of minimally invasive surgery, 11 of which had tool-induced bleeding. Our preliminary testing shows that the algorithm is 88% accurate and 90% precise in predicting bleeding. The average advance warning time for the 11 videos is 0.662 s, with the standard deviation being 0.427 s. The proposed approach has the potential to eventually lead to a surgical early warning system or even proactively attenuate tool movement (for robotic surgery) to avoid dangerous surgical outcomes.
      Citation: Robotics
      PubDate: 2021-02-21
      DOI: 10.3390/robotics10010037
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 38: Accessible Educational Resources for Teaching
           and Learning Robotics

    • Authors: Maria Pozzi, Domenico Prattichizzo, Monica Malvezzi
      First page: 38
      Abstract: Robotics is now facing the challenge of deploying newly developed devices into human environments, and for this process to be successful, societal acceptance and uptake of robots are crucial. Education is already playing a key role in raising awareness and spreading knowledge about robotic systems, and there is a growing need to create highly accessible resources to teach and learn robotics. In this paper, we revise online available educational material, including videos, podcasts, and coding tools, aimed at facilitating the learning of robotics related topics at different levels. The offer of such resources was recently boosted by the higher demand of distance learning tools due to the COVID-19 pandemic. The potential of e-learning for robotics is still under-exploited, and here we provide an updated list of resources that could help instructors and students to better navigate the large amount of information available online.
      Citation: Robotics
      PubDate: 2021-02-23
      DOI: 10.3390/robotics10010038
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 39: Model-Based Flow Rate Control with Online
           Model Parameters Identification in Automatic Pouring Machine

    • Authors: Nobutoshi Kabasawa, Yoshiyuki Noda
      First page: 39
      Abstract: In this study, we proposed an advanced control system for tilting-ladle-type automatic pouring machines in the casting industry. Automatic pouring machines have been introduced recently to improve the working environment of the pouring process. In the conventional study on pouring control, it has been confirmed that the pouring flow rate control contributes to improving the accuracy of the entire automatic pouring machine, such as the outflow liquid’s falling position from the ladle, the liquid’s weight filled in the mold, and the sprue cup’s liquid level. However, the conventional control system has problems: it is not easy to precisely pour the liquid in the ladle with a large tilting angle, and it takes time to adjust the control parameters. Therefore, we proposed the feedforward pouring flow rate control system, constructed by the pouring process’ inverse model with the online model parameters identification. In this approach, we derived the pouring process’ mathematical model, representing precisely the pouring process with the ladle’s large tilting angle. The model parameters in the pouring process’ inverse model in the controller are updated online via the model parameters identification. To verify the proposed pouring control system’s efficacy, we experimented using the tilting-ladle-type automatic pouring machine. In the experimental results, the mean absolute error between the outflow liquid’s weight and the reference weight was improved from 0.1346 at the first pouring to 0.0498 at the fifth pouring. Moreover, the model parameters were identified within 4 s. Therefore, it enables updating the controller’s parameters within each pouring motion interval by the proposed approach.
      Citation: Robotics
      PubDate: 2021-03-02
      DOI: 10.3390/robotics10010039
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 40: A Review of Active Hand Exoskeletons for
           Rehabilitation and Assistance

    • Authors: Tiaan du Plessis, Karim Djouani, Christiaan Oosthuizen
      First page: 40
      Abstract: Disabilities are a global issue due to the decrease in life quality and mobility of patients, especially people suffering from hand disabilities. This paper presents a review of active hand exoskeleton technologies, over the past decade, for rehabilitation, assistance, augmentation, and haptic devices. Hand exoskeletons are still an active research field due to challenges that engineers face and are trying to solve. Each hand exoskeleton has certain requirements to fulfil to achieve their aims. These requirements have been extracted and categorized into two sections: general and specific, to give a common platform for developing future devices. Since this is still a developing area, the requirements are also shaped according to the advances in the field. Technical challenges, such as size requirements, weight, ergonomics, rehabilitation, actuators, and sensors are all due to the complex anatomy and biomechanics of the hand. The hand is one of the most complex structures in the human body; therefore, to understand certain design approaches, the anatomy and biomechanics of the hand are addressed in this paper. The control of these devices is also an arising challenge due to the implementation of intelligent systems and new rehabilitation techniques. This includes intention detection techniques (electroencephalography (EEG), electromyography (EMG), admittance) and estimating applied assistance. Therefore, this paper summarizes the technology in a systematic approach and reviews the state of the art of active hand exoskeletons with a focus on rehabilitation and assistive devices.
      Citation: Robotics
      PubDate: 2021-03-03
      DOI: 10.3390/robotics10010040
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 41: Development of a High-Speed, Low-Latency
           Telemanipulated Robot Hand System

    • Authors: Yuji Yamakawa, Yugo Katsuki, Yoshihiro Watanabe, Masatoshi Ishikawa
      First page: 41
      Abstract: This paper focuses on development of a high-speed, low-latency telemanipulated robot hand system, evaluation of the system, and demonstration of the system. The characteristics of the developed system are the followings: non-contact, high-speed 3D visual sensing of the human hand, intuitive motion mapping between human hands and robot hands, and low-latency, fast responsiveness to human hand motion. Such a high-speed, low-latency telemanipulated robot hand system can be considered to be more effective from the viewpoint of usability. The developed system consists of a high-speed vision system, a high-speed robot hand, and a real-time controller. For the developed system, we propose new methods of 3D sensing, mapping between the human hand and the robot hand, and the robot hand control. We evaluated the performance (latency and responsiveness) of the developed system. As a result, the latency of the developed system is so small that humans cannot recognize the latency. In addition, we conducted experiments of opening/closing motion, object grasping, and moving object grasping as demonstrations. Finally, we confirmed the validity and effectiveness of the developed system and proposed method.
      Citation: Robotics
      PubDate: 2021-03-03
      DOI: 10.3390/robotics10010041
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 42: Globally Optimal Redundancy Resolution with
           Dynamic Programming for Robot Planning: A ROS Implementation

    • Authors: Enrico Ferrentino, Federico Salvioli, Pasquale Chiacchio
      First page: 42
      Abstract: Dynamic programming techniques have proven much more flexible than calculus of variations and other techniques in performing redundancy resolution through global optimization of performance indices. When the state and input spaces are discrete, and the time horizon is finite, they can easily accommodate generic constraints and objective functions and find Pareto-optimal sets. Several implementations have been proposed in previous works, but either they do not ensure the achievement of the globally optimal solution, or they have not been demonstrated on robots of practical relevance. In this communication, recent advances in dynamic programming redundancy resolution, so far only demonstrated on simple planar robots, are extended to be used with generic kinematic structures. This is done by expanding the Robot Operating System (ROS) and proposing a novel architecture meeting the requirements of maintainability, re-usability, modularity and flexibility that are usually required to robotic software libraries. The proposed ROS extension integrates seamlessly with the other software components of the ROS ecosystem, so as to encourage the reuse of the available visualization and analysis tools. The new architecture is demonstrated on a 7-DOF robot with a six-dimensional task, and topological analyses are carried out on both its state space and resulting joint-space solution.
      Citation: Robotics
      PubDate: 2021-03-04
      DOI: 10.3390/robotics10010042
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 43: Mechatronic Re-Design of a Manual Assembly
           Workstation into a Collaborative One for Wire Harness Assemblies

    • Authors: Ilaria Palomba, Luca Gualtieri, Rafael Rojas, Erwin Rauch, Renato Vidoni, Andrea Ghedin
      First page: 43
      Abstract: Nowadays, the wire harness assembly process is still manually performed due to the process complexity and product variability (e.g., wires of different kind, size and length). The Wire cobots project, in which this work was conceived, aims at improving the current state-of-art assembly process by introducing in it collaborative robotics. A shared workstation exploiting human abilities and machine strengths was developed to assembly automotive wire harness by means of insulated tape for a real industrial case. In the new workstation, the human deals with the complex task of wire handling, while the robot performs the repetitive and strenuous taping operations. Such a task allocation together with the workstation redesign allow for an improvement of the operator’s well-being in terms of postural conditions and for an increase of the production efficiency. In this paper, the mechanical and mechatronic design, as well as the realization and validation of this new collaborative workstation are presented and discussed.
      Citation: Robotics
      PubDate: 2021-03-05
      DOI: 10.3390/robotics10010043
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 44: Determining Robotic Assistance for Inclusive
           Workplaces for People with Disabilities

    • Authors: Elodie Hüsing, Carlo Weidemann, Michael Lorenz, Burkhard Corves, Mathias Hüsing
      First page: 44
      Abstract: Human–robot collaboration (HRC) provides the opportunity to enhance the physical abilities of severely and multiply disabled people thus allowing them to work in industrial workplaces on the primary labour market. In order to assist this target group optimally, the collaborative robot has to support them based on their individual capabilities. Therefore, the knowledge about the amount of required assistance is a central aspect for the design and programming of HRC workplaces. The paper introduces a new method that bases the task allocation on the individual capabilities of a person. The method obtains human capabilities on the one hand and the process requirements on the other. In the following step, these two profiles are compared and the workload of the human is acquired. This determines the amount of support or assistance, which should be provided by a robot capable of HRC. In the end, the profile comparison of an anonymized participant and the concept of the human–robot workplace is presented.
      Citation: Robotics
      PubDate: 2021-03-05
      DOI: 10.3390/robotics10010044
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 45: Cobot User Frame Calibration: Evaluation and
           Comparison between Positioning Repeatability Performances Achieved by
           Traditional and Vision-Based Methods

    • Authors: Roberto Pagani, Cristina Nuzzi, Marco Ghidelli, Alberto Borboni, Matteo Lancini, Giovanni Legnani
      First page: 45
      Abstract: Since cobots are designed to be flexible, they are frequently repositioned to change the production line according to the needs; hence, their working area (user frame) needs to be often calibrated. Therefore, it is important to adopt a fast and intuitive user frame calibration method that allows even non-expert users to perform the procedure effectively, reducing the possible mistakes that may arise in such contexts. The aim of this work was to quantitatively assess the performance of different user frame calibration procedures in terms of accuracy, complexity, and calibration time, to allow a reliable choice of which calibration method to adopt and the number of calibration points to use, given the requirements of the specific application. This has been done by first analyzing the performances of a Rethink Robotics Sawyer robot built-in user frame calibration method (Robot Positioning System, RPS) based on the analysis of a fiducial marker distortion obtained from the image acquired by the wrist camera. This resulted in a quantitative analysis of the limitations of this approach that only computes local calibration planes, highlighting the reduction of performances observed. Hence, the analysis focused on the comparison between two traditional calibration methods involving rigid markers to determine the best number of calibration points to adopt to achieve good repeatability performances. The analysis shows that, among the three methods, the RPS one resulted in very poor repeatability performances (1.42 mm), while the three and five points calibration methods achieve lower values (0.33 mm and 0.12 mm, respectively) which are closer to the reference repeatability (0.08 mm). Moreover, comparing the overall calibration times achieved by the three methods, it is shown that, incrementing the number of calibration points to more than five, it is not suggested since it could lead to a plateau in the performances, while increasing the overall calibration time.
      Citation: Robotics
      PubDate: 2021-03-08
      DOI: 10.3390/robotics10010045
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 46: On the Impact of Gravity Compensation on
           Reinforcement Learning in Goal-Reaching Tasks for Robotic Manipulators

    • Authors: Jonathan Fugal, Jihye Bae, Hasan A. Poonawala
      First page: 46
      Abstract: Advances in machine learning technologies in recent years have facilitated developments in autonomous robotic systems. Designing these autonomous systems typically requires manually specified models of the robotic system and world when using classical control-based strategies, or time consuming and computationally expensive data-driven training when using learning-based strategies. Combination of classical control and learning-based strategies may mitigate both requirements. However, the performance of the combined control system is not obvious given that there are two separate controllers. This paper focuses on one such combination, which uses gravity-compensation together with reinforcement learning (RL). We present a study of the effects of gravity compensation on the performance of two reinforcement learning algorithms when solving reaching tasks using a simulated seven-degree-of-freedom robotic arm. The results of our study demonstrate that gravity compensation coupled with RL can reduce the training required in reaching tasks involving elevated target locations, but not all target locations.
      Citation: Robotics
      PubDate: 2021-03-09
      DOI: 10.3390/robotics10010046
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 47: Service Robots in the Healthcare Sector

    • Authors: Jane Holland, Liz Kingston, Conor McCarthy, Eddie Armstrong, Peter O’Dwyer, Fionn Merz, Mark McConnell
      First page: 47
      Abstract: Traditionally, advances in robotic technology have been in the manufacturing industry due to the need for collaborative robots. However, this is not the case in the service sectors, especially in the healthcare sector. The lack of emphasis put on the healthcare sector has led to new opportunities in developing service robots that aid patients with illnesses, cognition challenges and disabilities. Furthermore, the COVID-19 pandemic has acted as a catalyst for the development of service robots in the healthcare sector in an attempt to overcome the difficulties and hardships caused by this virus. The use of service robots are advantageous as they not only prevent the spread of infection, and reduce human error but they also allow front-line staff to reduce direct contact, focusing their attention on higher priority tasks and creating separation from direct exposure to infection. This paper presents a review of various types of robotic technologies and their uses in the healthcare sector. The reviewed technologies are a collaboration between academia and the healthcare industry, demonstrating the research and testing needed in the creation of service robots before they can be deployed in real-world applications and use cases. We focus on how robots can provide benefits to patients, healthcare workers, customers, and organisations during the COVID-19 pandemic. Furthermore, we investigate the emerging focal issues of effective cleaning, logistics of patients and supplies, reduction of human errors, and remote monitoring of patients to increase system capacity, efficiency, resource equality in hospitals, and related healthcare environments.
      Citation: Robotics
      PubDate: 2021-03-11
      DOI: 10.3390/robotics10010047
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 48: Motion Planning and Control of an
           Omnidirectional Mobile Robot in Dynamic Environments

    • Authors: Mahmood Reza Azizi, Alireza Rastegarpanah, Rustam Stolkin
      First page: 48
      Abstract: Motion control in dynamic environments is one of the most important problems in using mobile robots in collaboration with humans and other robots. In this paper, the motion control of a four-Mecanum-wheeled omnidirectional mobile robot (OMR) in dynamic environments is studied. The robot’s differential equations of motion are extracted using Kane’s method and converted to discrete state space form. A nonlinear model predictive control (NMPC) strategy is designed based on the derived mathematical model to stabilize the robot in desired positions and orientations. As a main contribution of this work, the velocity obstacles (VO) approach is reformulated to be introduced in the NMPC system to avoid the robot from collision with moving and fixed obstacles online. Considering the robot’s physical restrictions, the parameters and functions used in the designed control system and collision avoidance strategy are determined through stability and performance analysis and some criteria are established for calculating the best values of these parameters. The effectiveness of the proposed controller and collision avoidance strategy is evaluated through a series of computer simulations. The simulation results show that the proposed strategy is efficient in stabilizing the robot in the desired configuration and in avoiding collision with obstacles, even in narrow spaces and with complicated arrangements of obstacles.
      Citation: Robotics
      PubDate: 2021-03-17
      DOI: 10.3390/robotics10010048
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 49: Dynamic and Friction Parameters of an
           Industrial Robot: Identification, Comparison and Repetitiveness Analysis

    • Authors: Lei Hao, Roberto Pagani, Manuel Beschi, Giovanni Legnani
      First page: 49
      Abstract: This paper describes the results of dynamic tests performed to study the robustness of a dynamics model of an industrial manipulator. The tests show that the joint friction changes during the robot operation. The variation can be identified in a double exponential law and thus the variation can be predicted. The variation is due to the heat generated by the friction. A model is used to estimate the temperature and related friction variation. Experimental data collected on two robots EFORT ER3A-C60 are presented and discussed. Repetitive tests performed on different days showed that the inertial and friction parameters can be robustly estimated and that the value of the measured joint friction can be used to estimate the unexpected conditions of the joints. Future applications may include sensorless identification of collisions, predictive maintenance programs, or human–robot interaction.
      Citation: Robotics
      PubDate: 2021-03-19
      DOI: 10.3390/robotics10010049
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 50: Industrial Robot Trajectory Tracking Control
           Using Multi-Layer Neural Networks Trained by Iterative Learning Control

    • Authors: Shuyang Chen, John T. Wen
      First page: 50
      Abstract: Fast and precise robot motion is needed in many industrial applications. Most industrial robot motion controllers allow externally commanded motion profiles, but the trajectory tracking performance is affected by the robot dynamics and joint servo controllers, to which users have no direct access and about which they have little information. The performance is further compromised by time delays in transmitting the external command as a setpoint to the inner control loop. This paper presents an approach for combining neural networks and iterative learning controls to improve the trajectory tracking performance for a multi-axis articulated industrial robot. For a given desired trajectory, the external command is iteratively refined using a high-fidelity dynamical simulator to compensate for the robot inner-loop dynamics. These desired trajectories and the corresponding refined input trajectories are then used to train multi-layer neural networks to emulate the dynamical inverse of the nonlinear inner-loop dynamics. We show that with a sufficiently rich training set, the trained neural networks generalize well to trajectories beyond the training set as tested in the simulator. In applying the trained neural networks to a physical robot, the tracking performance still improves but not as much as in the simulator. We show that transfer learning effectively bridges the gap between simulation and the physical robot. Finally, we test the trained neural networks on other robot models in simulation and demonstrate the possibility of a general purpose network. Development and evaluation of this methodology are based on the ABB IRB6640-180 industrial robot and ABB RobotStudio software packages.
      Citation: Robotics
      PubDate: 2021-03-21
      DOI: 10.3390/robotics10010050
      Issue No: Vol. 10, No. 1 (2021)
  • Robotics, Vol. 10, Pages 51: Explanations from a Robotic Partner Build
           Trust on the Robot’s Decisions for Collaborative Human-Humanoid

    • Authors: Misbah Javaid, Vladimir Estivill-Castro
      First page: 51
      Abstract: Typically, humans interact with a humanoid robot with apprehension. This lack of trust can seriously affect the effectiveness of a team of robots and humans. We can create effective interactions that generate trust by augmenting robots with an explanation capability. The explanations provide justification and transparency to the robot’s decisions. To demonstrate such effective interaction, we tested this with an interactive, game-playing environment with partial information that requires team collaboration, using a game called Spanish Domino. We partner a robot with a human to form a pair, and this team opposes a team of two humans. We performed a user study with sixty-three human participants in different settings, investigating the effect of the robot’s explanations on the humans’ trust and perception of the robot’s behaviour. Our explanation-generation mechanism produces natural-language sentences that translate the decision taken by the robot into human-understandable terms. We video-recorded all interactions to analyse factors such as the participants’ relational behaviours with the robot, and we also used questionnaires to measure the participants’ explicit trust in the robot. Overall, our main results demonstrate that explanations enhanced the participants’ understandability of the robot’s decisions, because we observed a significant increase in the participants’ level of trust in their robotic partner. These results suggest that explanations, stating the reason(s) for a decision, combined with the transparency of the decision-making process, facilitate collaborative human–humanoid interactions.
      Citation: Robotics
      PubDate: 2021-03-23
      DOI: 10.3390/robotics10010051
      Issue No: Vol. 10, No. 1 (2021)
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