Research On Delay-dependent Robust Fault-Tolerant Control For Networked Control System Based On The Model With Multiple Successive Delays In The State

Networked control system(NCS) is a kind of feedback control systems where the control loops are closed through real-time control network.In engineering practice,As networked control systems become more scatter, complexity and huge , it becom more vulnerable to faults. The damage will be immeasurable and irreplaceable to personnel or the environment if the faults happen . A cost effective way to obtain increased availability and reliability in networked control systems is to introduce fault-tolerant control. Therefore, the research on fault-tolerant control of networked control system has theoretical and applied significance.In recent years, the research on fault-tolerant control of networked control systems has made some preliminary results. In genaral, on performance, scholars mostly study the robust integrity and robust H_∞integrity problem of NCS, but in engineering practice, people not only hope to stabilize the closed loop system when failure occurs, but also want to have certain properties; On modeling, scholars mostly use the single delay model, and the lower bound of time-delay is restricted to be 0, that makes the result has a large conservative; On the law of control, scholars all use state feedback control law. Based on this, for reducing conservative, this paper uses state feedback control law and dynamic output feedback respectively, based on the model with multiple successive delays in the state, and focus on the time delay and the data packet dropout of NCS, the robust fault-tolerant control of uncertain networked control systems (NCS) is studied in this dissertation.Firstly, using state feedback control law, based on the Lyapunov stability theory and the technique of Linear Matrix inequalities(LMIs), considering with and without limited outside disturbances respectively, the robust integrity , robust H_∞integrity , robust guaranteed cost control and robust H_∞guaranteed cost control of NCS with time-varying delay and packet dropout delay are studied. A stability delay-depandent criterion for the closed-loop system with robust integrity , robust H_∞integrity , robust guaranteed cost integrity and robust H_∞guaranteed cost integrity against actuator or sensor failures are given through the structure of the appropriate lyapunov– krasovskii, moreover, a method of the robust fault-tolerant controller design is given, and the design problems of the optimal fault-tolerant H_∞, robust guaranteed cost and robust H_∞guaranteed cost fault-tolerant controllers are given via LMIs constraints respectively.Secondly, using dynamic output feedback control law, considering with and without outside limited disturbances respectively, the robust integrity and robust H_∞integrity of NCS with time-varying delay and packet dropout delay are studied. Without using the augmented state-space method to rebuild system model, and by using Lyapunov-Krasovskii functional , the sufficient conditions for closed-loop networked control system with uncertain time-varying delay and packet dropout possessing robust integrity and robust H_∞integrity against actuator failures are given by adopting dynamic output feedback control law, and by using an improved separation lemma, the design problems of the robust fault-tolerant and robust H_∞fault-tolerant controllers are given via liner matrix inequalities respectively.Finally, Based on the above conclusions, using simulation examples of all simulation results. The results show that paper concluded that the correct and effective. The less conservative results is obtained since the lower bound of the time-delay and appropriate free-weighting matrices being introduced, moreover without model transfirmation , scaling-up of cross terms and merging delays during the proof.