Fault-tolerant control method for networked control system with time-varying delay

Abstract

The invention discloses a fault-tolerant control method for a networked control system with time-varying delay. In view of conditions of parameter perturbation, time-varying delay, external disturbance and random failure happening to an actuator, a discrete time closed-loop nonlinear networked control system model is firstly built, a Lyapunov-Krasovskii function with the delay information is then built, a Lyapunov stability theory and a linear matrix inequality analysis method are used, sufficient condition for asymptotic stability of the nonlinear networked control system and existence of an H-infinity fault-tolerant controller are obtained, a Matlab LMI toolbox is used for solution, and a gain matrix for a non-fragile fault-tolerant controller is: K=K<->P; and conditions for optimizing the minimum disturbance rejection rate gamma is given, and the controller gain matrix K<*> optimized under the minimum disturbance rejection rate gammamin= square root of e is acquired. The condition of time-varying delay existing in the system is considered, the time-varying delay is analyzed and processed based on a free-weighting matrix method, and the conservation is reduced.

Description

technical field [0001] The invention relates to networked control systems and fault-tolerant control, in particular to a non-fragile H ∞ fault-tolerant control method. Background technique [0002] In the past two decades, many experts and scholars have conducted a lot of research on networked control systems (NCSs for short), seeking new design methods to deal with actuator failures and maintain system stability and Make the system have acceptable performance. In related studies, the models of actuator faults are generally divided into three types: 1) the fault parameters of the actuator are known constants, and there are only two cases of complete normal or complete failure; 2) the fault parameters of the actuator are unknown, the lower limit and upper limit of the fault parameter are known; 3) the actuator fault parameter is an unknown random variable, and the expectation and variance of the fault parameter are known. Most studies focus on the first and second types, w...

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Problems solved by technology

[0004] Currently non-fragile robust H ∞ Although the problem of fault-tolerant control has been studied a lot, there are relatively few studies on the problem of external disturbances in nonlinear systems and random faults of actuators, especially the research on random faults of actuators

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