Variable structure optimal fault-tolerant control based on internal model principle

A physically realizable variable structure dynamic optimal fault-tolerant control approach is proposed for systems with actuator and/or sensor faults,which considers the influence of the faults on inner states and outer outputs of systems at the same time.Firstly,a fault compensator is designed to compensate the influence of faults on the outputs of systems by utilizing internal model principle.Then,a dynamic optimal fault-tolerant control law for faulty systems is designed by utilizing Riccati matrix equation.To solve the physically unrealizable problem of the optimal fault-tolerant control,a new reduced-order fault diagnosor is employed which realizes the fault diagnosis and the state observation of systems.Finally,the design steps are given for the dynamic optimal fault-tolerant control which can regulate with the variable structure according to the occurrence of faults.A simulation example shows the effectiveness and reliability of the proposed approach.