Fault-tolerant Controller Design For A Class Of Discrete Time-delay Systems

As an important type of control systems,discrete time delay systems possess a wide background of practical applications.They have attracted much attention of research.On the other hand,with the development and modernization of our industry,people become increasingly concerned about the security and reliability other than the high-speed and high-performance of the products.The fault-tolerant control,as an important measure to improve the reliability of the control systems,has been paid more and more attention recently. Therefore,research on the discrete time delay system with fault-tolerant control is full of theoretical sense and application value,and now,it is a hot issue in control field.Based on Lyapunov stability theory together with linear matrix inequality(LMI) technique,this thesis investigates the discrete time delay systems.The main work is as follows:Firstly,the discrete time delay system with uncertain parameters and controller failure is studied and modeled as a switched time delay system.Based on average dwell time scheme and piecewise Lyapunov function,a sufficient condition on the existence of the state feedback controllers is obtained,and the gain of the controllers is given in terms of LMI s.Moreover, an estimate of state decay can be easily calculated by the corresponding linear matrix inequalities.A numerical example is given to illustrate the design procedure and its effectiveness.Then,the discrete time delay system with both state and input delay is studied.The considered system is represented in terms of switched time delay system including unstable subsystems.Using average dwell time method and piecewise Lyapunov function,the design method for the closed-loop system stable is obtained in terms of LMI s.A simulation result illustrates the effectiveness of the proposed method.Finally,the results of the thesis are summarized and the further research problems are pointed out.