Adaptive Fuzzy Output Feedback FTC For Uncertain Nonstrict-Feedback Nonlinear System

In this thesis,several typical uncertain nonlinear systems are considered,and the design problem of fault-tolerant control is studied by introducing the method of compensating different faults and the method of finite time control.In the framework of Backstepping,the control algorithm for sensor fault processing and the finite time control algorithm for actuator fault processing are designed respectively by using fuzzy logic system theory,Nussbaum technology and projection operator technology,and the stability of the system is proved.The main work of this paper is as follows:For a class of non-strict feedback nonlinear systems with unknown control direction and actuator failure and stuck fault,a finite-time output feedback fault-tolerant control algorithm is designed under the condition that the system is required to be stable in finite time.In the process of control design,the problem that the system state cannot be measured is dealt with by designing the observer,and the "algebraic loop" problem and the actuator failure jail-death problem are dealt with respectively by introducing the characteristics of fuzzy basis function and Nussbaum gain function.In the framework of Backstepping,a finite time controller for compensating actuator failure and dead-stuck fault is designed successfully.The stability and feasibility of the system are analyzed by the finite time Lyapunov stability theory.An output feedback fault-tolerant control algorithm is designed for a class of non-strict feedback nonlinear systems with actuator dead zone and sensor failure.In the process of control design,the problem that the system state cannot be measured is solved by designing the observer,the cubic absolute value Lyapunov function is constructed,and the projection technology and the dead zone inverse technology are introduced to deal with the sensor failure and dead zone problems successfully.In the framework of Backstepping,the controller for compensating sensor failure is designed successfully.The stability and feasibility of the system are analyzed by Lyapunov stability theory.A finite time output feedback fault-tolerant control algorithm was designed for a class of nonlinear large scale systems with non-strict feedback when the actuator failure deviation fault and output constraint existed simultaneously.In the process of control design,the problem that the system state can not be measured is solved by the design observer.Based on the decentralized control method,the actuator fault processing method and the obstacle Lyapunov function,the centralized control of the system,the compensation of the actuator failure deviation fault and the constraint of the system output are realized respectively.Under the framework of Backstepping,a finite time decentralized controller for compensating actuator failure deviation fault is designed successfully.The stability and feasibility of the system are analyzed by the finite time Lyapunov stability theory.A finite time output feedback fault-tolerant control algorithm is proposed for a class of non-strict feedback nonlinear systems with actuator failure deviation fault and random disturbance,and the system is required to be stable in finite time.In the process of control design,the problem that the system state cannot be measured is solved by the design observer.Based on Ito's Lemma and the projection method,the differential problem of the stochastic process and the failure deviation fault of the actuator are solved respectively.Under the framework of Backstepping,a stochastic finite time controller for compensating actuator failure deviation fault is designed successfully.The stability and feasibility of the system are analyzed by means of stochastic finite time Lyapunov stability theory.In order to further verify the effectiveness and feasibility of the proposed control method and theory,the corresponding numerical simulation examples are given respectively.