Research On Non-fragile Fault Tolerant Control For Networked Control Systems

The closed-loop control system formed by the communication network is called Networked control systems(NCSs).The NCSs have the advantages of easy installation and maintenance,high flexibility and easy reconstruction.However,the introduction of the communication network leads to problems such as network-induced delay,data packet loss and network congestion,and the external uncertainties may cause the system performance degradation or even instability.Therefore,it is necessary to make NCSs have fault-tolerant capability.For the NCSs with time delay,it is important to study the problems such that the uncertainties of the system parameters,the perturbation of the controller parameters,the anti-jamming performance of the system and the stability of the system with unknown failure or stochastic fault of the actuator.It has great theoretical value and far-reaching practical significance.The main contents of this course are:The problem is concerned with the unknown fault of the actuator and the non-fragile fault-tolerant stabilization for networked control system(NCS)with uncertain parameters,the perturbation of the controller parameters and time delays.A class of uncertain parameters is introduced to model the time-varying of the uncertain parameters.The mathematical model of the unknown failure of the actuator is established.By utilizing Lyapunov stability theory and linear matrix inequality(LMI)methods,a sufficient condition for the existence of the fault-tolerant controller is derived,and then the desired non-fragile controller gain is obtained by solving the LMIs.The non-fragile H_? fault-tolerant control problem is studied for a class of nonlinear NCSs with time delays and packet dropouts.The system parameters are allowed to have time-varying uncertainties and the controller exists perturbation.The actuator faults are assumed to occur in a random way satisfying Bernoulli distribution.NCSs are modeled as Markov jump systems.By utilizing Lyapunov stability theory and linear matrix inequality(LMI)methods,a sufficient condition for the existence of the H_? fault-tolerant controller is derived,and then the desired non-fragile controller gain is obtained by solving the LMIs.The designed controller ensures that the closed-loop NCSs are asymptotically stable and have good H_? performance.The problem of non-fragile robust H_? control for nonlinear NCSs with time-varying delay,the perturbation of the controller parameters,external disturbance and the unknown and random actuator faults is addressed.The system parameters are allowed to have time-varying uncertainties and a delay nonlinear system model is constructed.Construct the appropriate Lyapunov-Krasovskii function.Based on Lyapunov stability theory,linear matrix inequalities and free weighting matrix methods,the sufficient conditions for the existence of the non-fragile robust H_? controller gain are derived and which can be obtained by solving the LMIs.The designed controller ensures that the closed-loop NCSs are asymptotically stable and have good H_? performance.Finally,in order to illustrate the effectiveness of the proposed methods,specific numerical simulations are provided after the corresponding chapters.