Robust H_∞Fault-tolerant Control For Nonlinear Time-Delay Systems

With the progress of science and technology, the scale of modern engineering is being gradually expanded and technology is also more and more complex. Once a fault will cause great loss of property and personnel, it has importantly significance to provide system security and reliability. Fault-tolerant control technology provides an effective way for it. However, in the real system often exists the phenomenon of time delay and nonlinear factors, which makes it difficulty research the system fault-tolerant control.In this paper, Fault-tolerant Control of nonlinear time-delay systems which based on the Lyapunov stability theory and linear matrix inequality (LMI) method is investigated with actuator failures. Actuator failures are introduced with fault matrix and relevant results are given in the way of LMI. The mainly content includes the following three aspects:(1) We investigate robust H∞fault-tolerant control problem for a class of nonlinear time-varying delay systems. First, we analyze robust stability and H∞, performance for the system. Then a state feedback controller is designed not only to makes the closed-loop system be robust stability but also to make H∞norm for the transfer function matrix for the system be less than a given level of attenuation in the case of actuator failure and this conclusion is relevant to time delay. Finally, a numerical example is give to illustrate the validity of proposed method.(2) We study with a nonlinear time delay system. An output feedback controller based on a dynamic compensator is designed to makes the closed-loop system be robust stability and have a H∞. performance in the case of actuator failure. First, a sufficient condition which the system exists an output feedback robust H∞fault-tolerant controller is given. Then gives design method. Finally, a numerical example is give to illustrate the validity of proposed method.(3) We investigate robust H∞fault-tolerant control problem for a class of nonlinear time-varying delay switched systems in the case of actuator failure.First, we give a sufficient condition and the switching rules which make autonomous system be robust stability and have a H∞performance.Then, under actuator fault conditions, the memory delay-independent state feedback controller and switching rules which make the closed-loop system stable and satisfies the given performanceγare designed. Finally, a numerical example is give to illustrate the validity of proposed method.