Hybrid journal (It can contain Open Access articles) ISSN (Print) 1755-9340 - ISSN (Online) 1755-9359 Published by Inderscience Publishers[447 journals]
Authors:Abderrahim El-Amrani, Ahmed El Hajjaji, Ismail Boumhidi, Abdelaziz Hmamed Pages: 1 - 24 Abstract: This paper investigates the design problem of <i>H</i><SUB align="right">∞ filtering for discrete nonlinear systems in the Takagi-Sugeno (T-S) form. Our aim is to design a new filter guaranteeing an <i>H</i><SUB align="right">∞ performance level in specific finite frequency (FF) ranges. Using the well-known generalised Kalman Yakubovich Popov lemma, Finsler's lemma, sufficient conditions for the existence of <i>H</i><SUB align="right">∞ filters for different FF ranges are proposed and then unified in terms of solving a set of linear matrix inequalities (LMIs). Two examples are given to illustrate the effectiveness and the less conservatism of the proposed approach in comparison with the existing methods. Keywords: finite frequency; H∞ filtering; Takagi-Sugeno; fuzzy systems Citation: International Journal of Systems, Control and Communications, Vol. 11, No. 1 (2020) pp. 1 - 24 PubDate: 2020-02-27T23:20:50-05:00 DOI: 10.1504/IJSCC.2020.105391 Issue No:Vol. 11, No. 1 (2020)
Authors:Wesam Jasim, Dongbing Gu Pages: 25 - 51 Abstract: In this work, a leader-follower formation control problem of quadrotors is investigated. The quadrotor dynamic model is represented by unit quaternion with the consideration of external disturbance. Nonlinear <i>H</i><SUB align="right">∞ design approach is introduced and robust controllers for both leader and follower robots are derived by solving a Hamilton-Jacobi inequality following from a result for general nonlinear affine systems. Then some robustness conditions of the proposed controllers are obtained by selecting appropriate parametrised Lyapunov functions. The resultant state feedback controllers establish the asymptotically stability of the closed-loop nonlinear system. In addition, integral backstepping (IB) controllers are also derived for the leader-follower formation control problem. The purpose of designing IB controllers is to evaluate the robustness of <i>H</i><SUB align="right">∞ controllers by comparison. The simulation results from both types of controllers are compared and robustness performance of the <i>H</i><SUB align="right">∞ controllers over the IB controllers are demonstrated. Keywords: leader-follower formation; nonlinear H∞ control; integral backstepping control; unit quaternion; external disturbances Citation: International Journal of Systems, Control and Communications, Vol. 11, No. 1 (2020) pp. 25 - 51 PubDate: 2020-02-27T23:20:50-05:00 DOI: 10.1504/IJSCC.2020.105392 Issue No:Vol. 11, No. 1 (2020)
Authors:Tapan Prakash, S.P. Singh, V.P. Singh Pages: 52 - 67 Abstract: The analysis of higher order systems is tedious and cumbersome task. This motivated analysts to reduce higher order systems into lower order models using mathematical approaches. In this paper, an analytic hierarchy process (AHP)-based approximation of stable higher order systems to stable lower order models using sine cosine algorithm (SCA) is presented. The stable approximant is deduced by minimising the relative errors in between time moments and Markov parameters of the system and its approximant. In order to match the steady states of the system and its approximant, the first time moment of the system is retained in the approximant. AHP is utilised to convert multi-objective problem of minimisation of errors in between time moments and Markov parameters into a single objective problem by proper assignment of weights. To ensure the stability of the approximant, Hurwitz criterion is utilised. The systematic nature and efficacy of the proposed technique is validated by deriving approximants for three different test systems. Keywords: model reduction; Padé approximation; Routh approximation; sine cosine algorithm; SCA; analytic hierarchy process; AHP Citation: International Journal of Systems, Control and Communications, Vol. 11, No. 1 (2020) pp. 52 - 67 PubDate: 2020-02-27T23:20:50-05:00 DOI: 10.1504/IJSCC.2020.105393 Issue No:Vol. 11, No. 1 (2020)
Authors:Chirine Benzazah, Loubna Lazrak, Soukaina El Daoudi, Mustapha Ait Lafkih Pages: 68 - 91 Abstract: This paper deals with a part implementation of the distributed generation chain system based on hydraulic power source operated in low power and controlled by DSP F2812. The experimental part of the chain includes a controlled two-level three-phase inverter connected, via an LC filter, to a load. This latter consists of a balanced three-phase resistive without neutral point joint, for this reason, the implementation requires fewer sensors as measuring devices. The proposed control strategy uses just two regulation loops; one of them is for the AC output voltages and the other one is for the input inductor currents of LC filter. This strategy was developed on Matlab-Simulink and implemented in eZdsp TMS320F2812 DSP board from spectrum digital. To confirm the efficiency and robustness of the chain part implementation, the experimental results using the implemented inverter was compared with a compact industrial module 7MBR15SA120 inverter mounting with the same control interface and measurement cards. The experimental waveforms comparison prove that there is a good match between the two practice prototypes, validate the theoretical study as well as the simulation results obtained and confirm the effectiveness of the proposed control strategy. Keywords: three-phase inverter; DSP F2812 controller; CCS; MATLAB interface; digital model; power integrated module 7MBR15SA120; IRGPS60B120KDP Citation: International Journal of Systems, Control and Communications, Vol. 11, No. 1 (2020) pp. 68 - 91 PubDate: 2020-02-27T23:20:50-05:00 DOI: 10.1504/IJSCC.2020.105394 Issue No:Vol. 11, No. 1 (2020)
Authors:Chirine Benzazah, Loubna Lazrak, Soukaina El Daoudi, Mustapha Ait Lafkih Pages: 92 - 118 Abstract: Constant false alarm rate (CFAR) processors play a vital role in organising the heterogeneous detection of fluctuating targets. Specifically, the popular cell-averaging (CA) processor is incapable of maintaining its design false alarm rate when facing clutter with statistical variations. Order-statistics (OS) and trimmed-mean (TM) algorithms have been suggested to robustly estimate the heterogeneous threshold. They have, however, degraded homogeneous performance. For simultaneously exploiting the merits of CA, and OS or TM processors, a hybrid combination of them have been recently proposed. This paper deals with the analysis of these models. Closed-form expression is derived for their detection performance. The primary and outlying targets follow χ<SUP align="right">2</SUP>-distribution with four-degrees of freedom in their fluctuation. Our simulation results reveal that the new version CA_TM exhibits a homogeneous performance that outweighs that of Neyman-Pearson (N-P) detector which is employed as a baseline comparison for other techniques in the CFAR world. Keywords: adaptive processors; clutter and interference; derived detectors; χ2-distribution; SWIII and SWIV fluctuation models; post-detection integration; multi-target environments Citation: International Journal of Systems, Control and Communications, Vol. 11, No. 1 (2020) pp. 92 - 118 PubDate: 2020-02-27T23:20:50-05:00 DOI: 10.1504/IJSCC.2020.105395 Issue No:Vol. 11, No. 1 (2020)
Hybrid journal (It can contain Open Access articles)
