Fault-Tolerant Control For Semi-Markovian Jump Systems With Multiple Inputs

In recent years,with the rapid development of technology,the requirements of control system performance have become more stringent.In the practical industrial processes,the structure and parameters of the system will change due to changes in random parameters.The Markovian jump system(MJS)has powerful modeling capability for complex systems because of its own system characteristics.Therefore,it has received extensive attention from the control and engineering scholars,and its research results are increasingly applied to the practical system.However,because its transition rates are constant and many practical systems usually fail to meet this condition,which limits the application of its related results.Besides,the semi-Markovian jump system(S-MJS)has more widely applications due to relaxed conditions on the transition probability.Moreover,with the complexity of the system structure and the variability of the environment as well as widespread unmodelled dynamics,information channel noise,actuator faults and external disturbances in the practical industrial process,the study of such complex systems with multiple unknown inputs can improve the performance of control system.Therefore,it is of great theoretical and practical value to study the fault-tolerant control problem for the S-MJS with multiple inputs.In this paper,the composite hierarchical fault-tolerant control problem for S-MJS with multiple disturbances and time-varying fault is studied.When the modeling disturbance is mismatched,the disturbance-observer based integral sliding mode control problem for S-MJS with mismatched disturbance and time-varying fault is investigated.Besides,the event-triggered composite integral sliding mode control problem for S-MJS with mismatched disturbance and time-varying fault is presented.The main contributions of this thesis are listed as follows:(1)The composite hierarchical fault-tolerant control problem for the S-MJS with multiple disturbances and time-varying fault is investigated.Three types of faults(constant fault,sinusoidal fault,ramp fault)are considered and the multiple disturbances include the modeling disturbance and norm-bounded disturbance.By designing the reduce-order observer and combining H? control method,a composite hierarchical fault-tolerant control scheme is proposed.A special form of the composite hierarchical fault-tolerant controller incorporates one feedback control and two feedforward control.A simulation example is illustrated to verify the effectiveness of the proposed composite hierarchical fault-tolerant control scheme under three types of fault cases.(2)The integral sliding mode control problem for S-MJS with the modeling disturbance as mismatched disturbance is presented.First,by designing the disturbance observer and the fault diagnosis observer,the error system of disturbance and fault is obtained,the stability of the error system is analyzed,and the gain matrices of the observers is solved.Then,the disturbance-observer-based integral sliding mode control method is proposed to ensure the stochastic stability of the system and to compensate for the disturbance and fault.Furthermore,in order to reduce the calculation times of the controller,event-triggering control strategy is introduced.By designing an appropriate event-triggered mechanism,an event-triggered composite integral sliding mode control scheme is proposed to reduce the waster of communication resources based upon the premise of the stability of the system is guaranteed.Finally,the effectiveness of the proposed controllers under three types of faults are verified by simulations.