Research On Delay-dependent Robust Fault-tolerant Control For Networked Control System With Quantizing Error

Networked control system(NCS) is a kind of closed loop control system which is based oncommunication network in place of the traditional point-to-point connections. With the highdevelopment of NCS and the high demand of reliability, safety, NCS fault-tolerant control get highattention. In the research of the fault-tolerant control of NCS, the network bring many newproblems and challenges to the modeling, analysis and design of NCS, such as network inducedtime-delay, data packet loss, information quantification, and so on. Review the achievements on thefault-tolerant control of NCS in recent years, there is few paper studying the robust fault-tolerantcontrol of NCS with parameter uncertainties in the way of time-delay dependent, for consideringthe time-varying delay, packet loss and quantization error at a time.Based on this, this paper first considering the whole state of the controlled plant can bemeasured completely, using the state feedback strategy, with the uncertain NCS as the researchobject, considering the influence of network induced time-delay, data packet loss and informationquantification error, through the construction of delay and quantizing error dependent Lyapunov-Krasovskii functional, the problems of robust integrity, robust H_∞integrity of NCS with parameteruncertainties are studyed based on the Lyapunov stability theory and the technique of Linear Matrixinequalities(LMIs). A stability delay-depandent criterion for the closed-loop system with robustintegrity, robust H_∞integrity against actuator or sensor failures are given and the method of therobust fault-tolerant controller design are also given. Also to actuators failures, for example,discusses the maximum allowed time-delay and the maximum allowed quantizing error when theNCS operate stably, and on the basis of this, the optimized H_∞performance indexe and the methodof the optimal robust fault-tolerant controller design are given.Secondly, considering the whole state of the controlled object not complete measurement,using dynamic output feedback control law, taking the unascertain NCS as the research object,considering the influence of the network induced time-delay, data packet loss and informationquantification error, based on the model of state multi-delay time, with construction time-delay andquantizing error dependent Lyapunov-Krasovskii functional, using Lyapunov stability theory andLMI method, in the cases of sensors or actuators failures, the robust integrity and robustH_∞integrity of NCS are studied. The corresponding decision rules are inferred out. Thecorresponding robust fault-tolerant controller design method is given with the nonlinear termseparation effectively by using matrix separation lemma. And then discusses the maximum allowedtime-delay and the maximum allowed quantizing error when the NCS operate stably, and on thebasis of this, the optimized H_∞performance index and the method of the optimal robustfault-tolerant controller design are given.Finally, based on the above conclusions, using simulation examples show that paper concluded that the correct and effective. The less conservative results is obtained since the lowerbound of the time-delay and appropriate free-weighting matrices being introduced, moreoverwithout model transformation, scaling-up of cross terms during the proof. Analysising themaximum allowable delay and the maximum allowed quantizing error can proceed the optimizationscheduling control of NCS while the system is stable, can analysis the conservative of the resultsaccording to the above analysis, and also can improve the feasibility and satisfaction of the faulttolerance of NCS further with less conservative.