This paper addresses the adaptive tracking control scheme for switched nonlinear systems with unknown control gain sign. The approach relaxes the hypothesis that the upper bound of function control gain is known const...This paper addresses the adaptive tracking control scheme for switched nonlinear systems with unknown control gain sign. The approach relaxes the hypothesis that the upper bound of function control gain is known constant and the bounds of external disturbance and approximation errors of neural＇networks are known. RBF neural networks （NNs） are used to approximate unknown functions and an H-infinity controller is introduced to enhance robustness. The adaptive updating laws and the admissible switching signals have been derived from switched multiple Lyapunov function method. It＇s proved that the resulting closed loop system is asymptotically Lyapunov stable such that the output tracking error performance and H-infinity disturbance attenuation level are well obtained. Finally, a simulation example of Forced Duffing systems is given to illustrate the effectiveness of the proposed control scheme and improve significantly the transient performance.展开更多
This study deals with the robust H-infinity filtering for a class of Delta operator systems with polytopic uncertainties. By the aid of introducing two slack matrices to eliminate the coupling between systems matrices...This study deals with the robust H-infinity filtering for a class of Delta operator systems with polytopic uncertainties. By the aid of introducing two slack matrices to eliminate the coupling between systems matrices and Lya- punov matrices, an improved version of the bounded real lemma is given via linear matrix inequality formulation, which shows a close correspondence between the continuous- and discrete-time H-infinity performance criterion. Based on it, the existence condition of the desired filter is obtained such that the corresponding filtering error system is asymptotically stable with a guaranteed performance index. A numerical example is employed to illustrate the feasibility and advantages of the orooosed design.展开更多
This paper presents the design of a robust control system for a high-purity distillation column. It is concerned with the design of a two degree-of-freedom (2DOF) product-composition controller for a high-purity disti...This paper presents the design of a robust control system for a high-purity distillation column. It is concerned with the design of a two degree-of-freedom (2DOF) product-composition controller for a high-purity distillation column. The H<sub>∞</sub> optimization problem is set up to ensure a guaranteed level of robust stability, robust disturbance attenuation and robust reference tracking performance.展开更多
This paper presents an LMI based robust H-infinity control scheme for constrained systems with norm- bounded uncertainties. The uncertainties are incorporated in the evaluation of the H-infinity norm and the time-doma...This paper presents an LMI based robust H-infinity control scheme for constrained systems with norm- bounded uncertainties. The uncertainties are incorporated in the evaluation of the H-infinity norm and the time-domain constraints. The robust closed-loop properties inclusive of stability, H-infinity performance and the satisfaction of the time- domain constraints are discussed. Analysis and simulation results for a 2 DOF quarter-car model show possible improve- ments on ride comfort, while robustly respecting safety related constraints such as good road holding, limited suspension strokes and actuator saturation.展开更多
For a class of switched nonlinear systems, the BIBO stable domain is introduced in this paper. The robust H - infinity control problem for switched nonlinear systems with parameter uncertainty is investigated using th...For a class of switched nonlinear systems, the BIBO stable domain is introduced in this paper. The robust H - infinity control problem for switched nonlinear systems with parameter uncertainty is investigated using the BIBO stable domain.Aiming at the effect of parameter uncertainties,a switching strategy and each state feedback sub - controller design are stated to guarantee the H - infinity performance of the whole switched system based on La Salle invariant principle.展开更多
Robust fault diagnosis based on adaptive observer is studied for a class of nonlinear systems up to output injection. Adaptive fault updating laws are designed to guarantee the stability of the diagnosis system. The u...Robust fault diagnosis based on adaptive observer is studied for a class of nonlinear systems up to output injection. Adaptive fault updating laws are designed to guarantee the stability of the diagnosis system. The upper bounds of the state estimation error and fault estimation error of the adaptive observer are given respectively and the effects of parameter in the adaptive updating laws on fault estimation accuracy are also discussed. Simulation example demonstrates the effectiveness of the proposed methods and the analysis results.展开更多
An approach for adaptive observer-based fault estimate for nonlinear system is proposed.H-infinity theory is applied to analyzing the design method and stable conditions of the adaptive observer, from which both syste...An approach for adaptive observer-based fault estimate for nonlinear system is proposed.H-infinity theory is applied to analyzing the design method and stable conditions of the adaptive observer, from which both system state and fault can be estimated. It is proved that the fault estimate error is related to the given H-infinity track performance indexes,as well as to the changing rate of the fault and the Lipschitz constant of the nonlinear item.The design steps of the adaptive observer are proposed.The simulation results show that the observer has good performance for fault estimate even when the system includes nonlinear terms, which confirms the effectiveness of the method.展开更多
This paper focuses on the robust H-infinity reliable control for a class of nonlinear neutral delay systems with uncertainties and actuator failures. We design a state feedback controller in terms of linear matrix ine...This paper focuses on the robust H-infinity reliable control for a class of nonlinear neutral delay systems with uncertainties and actuator failures. We design a state feedback controller in terms of linear matrix inequality(LMI)such that the plant satisfies robust H-infinity performance for all admissible uncertainties, and actuator failures among a prespecified subset of actuators. An example is also given to illustrate the effectiveness of the proposed approach.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 60835001, 60804017)the Application Research Programs of Nantong City ( No. K2010057)the Open Project from digital manufacture technology Key Laboratory of Jiangsu Province (No. HGDML-0908)
文摘This paper addresses the adaptive tracking control scheme for switched nonlinear systems with unknown control gain sign. The approach relaxes the hypothesis that the upper bound of function control gain is known constant and the bounds of external disturbance and approximation errors of neural＇networks are known. RBF neural networks （NNs） are used to approximate unknown functions and an H-infinity controller is introduced to enhance robustness. The adaptive updating laws and the admissible switching signals have been derived from switched multiple Lyapunov function method. It＇s proved that the resulting closed loop system is asymptotically Lyapunov stable such that the output tracking error performance and H-infinity disturbance attenuation level are well obtained. Finally, a simulation example of Forced Duffing systems is given to illustrate the effectiveness of the proposed control scheme and improve significantly the transient performance.
基金supported by National Nature Science Foundation of China(No.60904031)the Specialized Research Fund for the Doctoral Program of Higher Education(No.0122302120069)+3 种基金the Basic Research Plan in Shenzhen City(No.JC201105160564A)the Project for Distinguished Young Scholars of the Basic Research Plan in Shenzhen City(No.JC201105160583A)the Fundamental Research Funds for the Central Universities(No.HIT.NSRIF.2011129)the Key Lab of Wind Power and Smart Grid in Shenzhen City(No.CXB201005250025A)
文摘This study deals with the robust H-infinity filtering for a class of Delta operator systems with polytopic uncertainties. By the aid of introducing two slack matrices to eliminate the coupling between systems matrices and Lya- punov matrices, an improved version of the bounded real lemma is given via linear matrix inequality formulation, which shows a close correspondence between the continuous- and discrete-time H-infinity performance criterion. Based on it, the existence condition of the desired filter is obtained such that the corresponding filtering error system is asymptotically stable with a guaranteed performance index. A numerical example is employed to illustrate the feasibility and advantages of the orooosed design.
文摘This paper presents the design of a robust control system for a high-purity distillation column. It is concerned with the design of a two degree-of-freedom (2DOF) product-composition controller for a high-purity distillation column. The H<sub>∞</sub> optimization problem is set up to ensure a guaranteed level of robust stability, robust disturbance attenuation and robust reference tracking performance.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.12MS49)the Program for Excellent Talents of Beijing(No.2011A009005000001)the Overseas Training Project for Young Key Teachers(No.[2011]3022)
文摘This paper presents an LMI based robust H-infinity control scheme for constrained systems with norm- bounded uncertainties. The uncertainties are incorporated in the evaluation of the H-infinity norm and the time-domain constraints. The robust closed-loop properties inclusive of stability, H-infinity performance and the satisfaction of the time- domain constraints are discussed. Analysis and simulation results for a 2 DOF quarter-car model show possible improve- ments on ride comfort, while robustly respecting safety related constraints such as good road holding, limited suspension strokes and actuator saturation.
基金partially supported by the Natural Science Foundation of China under Grant No. 60764001the West Light Talent Project of The Chinese Academy of Sciences(2007414)the Indraught Talents Foundation of Guizhou University(2007)
文摘For a class of switched nonlinear systems, the BIBO stable domain is introduced in this paper. The robust H - infinity control problem for switched nonlinear systems with parameter uncertainty is investigated using the BIBO stable domain.Aiming at the effect of parameter uncertainties,a switching strategy and each state feedback sub - controller design are stated to guarantee the H - infinity performance of the whole switched system based on La Salle invariant principle.
基金This work was supported by the National Natural Science Foundation of China (No. 60534010,60572070, 60521003) and the Program for Changjiang Scholars and Innovative Research Team in University.
文摘Robust fault diagnosis based on adaptive observer is studied for a class of nonlinear systems up to output injection. Adaptive fault updating laws are designed to guarantee the stability of the diagnosis system. The upper bounds of the state estimation error and fault estimation error of the adaptive observer are given respectively and the effects of parameter in the adaptive updating laws on fault estimation accuracy are also discussed. Simulation example demonstrates the effectiveness of the proposed methods and the analysis results.
文摘An approach for adaptive observer-based fault estimate for nonlinear system is proposed.H-infinity theory is applied to analyzing the design method and stable conditions of the adaptive observer, from which both system state and fault can be estimated. It is proved that the fault estimate error is related to the given H-infinity track performance indexes,as well as to the changing rate of the fault and the Lipschitz constant of the nonlinear item.The design steps of the adaptive observer are proposed.The simulation results show that the observer has good performance for fault estimate even when the system includes nonlinear terms, which confirms the effectiveness of the method.
基金This work was supported by the National Natural Science Foundation of China (No. 60274009)the SRFDP (No. 20020145007)the Natural Science Foundation of Liaoning Province (No.20032020).
文摘This paper focuses on the robust H-infinity reliable control for a class of nonlinear neutral delay systems with uncertainties and actuator failures. We design a state feedback controller in terms of linear matrix inequality(LMI)such that the plant satisfies robust H-infinity performance for all admissible uncertainties, and actuator failures among a prespecified subset of actuators. An example is also given to illustrate the effectiveness of the proposed approach.
