Research Of Fault-tolerant Control For The Complex Control Systems

The reliability of control systems is the key to operate normally for the systems. It has very important signification to ensure the reliability and the security of modern complex systems. The coming of the fault-diagnosis and fault-tolerant control technology provides a new method to improve the reliability of modern complex systems. Because of the common existence of time-delay, the study of the fault-tolerant control problem of time-delay systems has an important value in theory and practice. Robust fault-tolerant control is the focus in the research of fault-tolerant control (FTC) recently. It is to design a robust controller in advance to ensure the system possessing integrity against sensor or actuator failures. In this paper, based on a general representation of sensor and actuator failures, we study some kinds of robust fault-tolerant control problems for uncertain systems and uncertain time-delay systems. The contributions of this paper are as follows:First, the robust fault-tolerant control problem of time-delay uncertain system is studied. Using the linear matrix inequality (LMI) method, concern the linear systems with norm-bounded uncertainties, the design methods of robust fault-tolerant controller and the design of controller that guarantee certain robust performance by state feedback are investigated. The sufficient condition is given to maintain the asymptotic stability of the time-delay uncertain system with actuator failures, and the design method of the controller is also provided. Then, the robust fault-tolerant control problem of time-delay uncertain system with sensor failures is studied. The proposed of the memory controller diminished the effects of the time-delay of the system to the control of the system effectively.Second, the fault-tolerant control problem of discrete time-delay uncertain system is studied. The sufficient condition of the existence of the fault-tolerant controller is derived to keep the asymptotically stability of the discrete time-delay uncertain system with actuator failures via LMI method, and the design method of the memory controller is also given, so that ,diminished the effect of the state time-delay to the control of the system. Then, the robust fault-tolerant control problem of discrete time-delay uncertain system with sensor failures is considered. At last, we solved the controller parameters via the LMI toolbox in the Matlab. The effectiveness of the proposed design method is illustrated through simulation results.Third, the fault-tolerant control problem of multiple time-delay uncertain system is studied. First, we analyzed the stabilization of the system, then the sufficient condition of the existence of the fault-tolerant controller is derived to keep the asymptotically stability of the multiple time-delay uncertain system with actuator failures, and the design method of the controller is also given. The LMI method we used in this paper can avoid the parameters made up when used the parameter-space design method and Riccati design method, so that we made the conservative property reduced.