Adaptive Fault Tolerant Control Based On Sliding Mode For Two Class Of Stochastic Systems

With the progress of the times and the improvement of automation,stochastic systems are more and more widely used in the production activities of human society.They involve fire control system,industrial process control,economic model control and biomedical field-s.In stochastic control systems,continuous-time stochastic systems are one of the most im-portant branches,which can be described by a stochastic differential equation.Accurate modeling of the actual system,and then formulating appropriate control strategies to make the system stable has been the focus of scholars.With the deepening of research,the mod-eled systems become more and more complex,which usually include time delay,uncertain parameters,non-linearity and external interference.Especially when sudden actuator or sen-sor faults occur in the system,how to adopt the corresponding fault-tolerant control strategy according to the fault information to ensure the stability of the system and meet the expected performance indicators poses a higher challenge to us.Based on the sliding mode control theory,the fault-tolerant control of two kinds of stochastic systems in the event of failure is studied by fully utilizing Lyapunov function,adaptive control and linear matrix inequality.The main contributions of this paper are as follows:Firstly,a non-fragile sliding mode observer is designed for a nonlinear uncertain time-varying delay Markov jump system with actuator additive faults.An adaptive compensation control law is designed according to the fault estimation,which makes the system stable and passive.Secondly,an augmented sliding mode observer is designed for a Markov jump system with actuator and sensor faults simultaneously.In this paper,a fault estimation strategy is presented,which makes the additive faults of system actuators more accurately estimated,whether constant or time-varying.On this basis,the sliding mode control law is designed to make the system stable and has H? performance.Finally,the problem of fault-tolerant control for semi-Markov jump systems with Weibul-1 distribution of dwell time is considered.In the case of actuator failure and actuator jam,column full rank factorization method and adaptive technique are introduced,and fuzzy logic system is used to approximate the nonlinear function with unknown upper bound.Based on sliding mode control method,sufficient conditions for asymptotic stability of semi-Markov jumping system are obtained.