The Fault-Tolerant Control And The Pole Assignment For Uncertain Switched Systems Based On LMI Approach

As an important type of the hybrid systems,uncertain switched systems have extensive applicability.When the large complex equipment is running,multiple subsystems are frequently switched in this equipment.If some sensors or actuators of subsystems in aging or failure may cause the whole system cannot work normally or even damage,resulting in huge economic losses.If the fault-tolerant control technique is introduced to the uncertain switched system,it can help to improve the stability and reliability of uncertain switched systems and assurance the system even under the condition of normal operation of.Based on Lyapunov stability theory and linear matrix inequality(LMI),the problem of stability,the pole assignment and disturbance attenuation level for three classes of uncertain nonlinear switched systems by state feedback are studied.The uncertain nonlinear switched systems include with state uncertainty and nonlinear term,with input uncertainty and nonlinear term,with state uncertainty and input uncertainty and nonlinear term.The main contributions of this thesis are listed as follows:(1)The problems of stability,the pole assignment and disturbance attenuation level for several classes of uncertain switched systems are studied.Respectively considering the uncertain nonlinear switched systems include with state uncertainty and nonlinear term,with input uncertainty and nonlinear term,with state uncertainty and input uncertainty and nonlinear term.When all the subsystems are not exponentially stable,based on common Lyapunov function approach and linear matrix inequality(LMI).By memory less state feedback control law,and the sufficient conditions of the designed controller can make the states of the uncertain switched systems asymptotically stable under the arbitrary switching strategy,each subsystem's eigenvalues are inside a chosen circle on the open left-half complex plane and minimum disturbance attenution level.Finally the simulation shows that the conclusion is correct and effective.(2)The problem of fault-tolerant control for several classes of uncertain switched linear systems are studied.Respectively considering the uncertain nonlinear switched systems include with input uncertainty and nonlinear term,with state uncertainty and input uncertainty and nonlinear term.When all the subsystems are not exponentially stable,based on common Lyapunov function approach and linear matrix inequality(LMI),a method of robust fault-tolerant control against sensor and actuator failures at the same time for uncertain systems is presented via memoryless state feedback control law.And the sufficient conditions of the designed controller can make the states of the uncertain switched systems asymptotically stable,each subsystem's eigenvalues are inside a chosen circle on the open left-half complex plane and minimum disturbance attenution level.Finally the simulation shows that the conclusion is correct and effective.