The Research On Fault Estimation For A Class Of Nonlinear Multi-agent Systems And Reliability Control For Active Suspension System In Finite Frequency Domain

The research on fault estimation and reliability control based on robust reliability algorithm has attracted wide attention in recent years.However,the existence of noise and disturbance may have a great impact on the fault estimation system and the reliability control system,and even lead to false alarms.In order to improve the stability and robustness of the system,it is also necessary to detect and estimate the failure of the system in time so as to make appropriate treatment and avoid the occurrence of accidents.This paper uses robust as the performance index to study the design method of fault estimation observer for nonlinear multi-agent in entire frequency domain and finite frequency domain,as well as the design method of reliability controller for active suspension linear variable parameter(LPV)system in finite frequency domain.The main contents are as follows:(1)In the case of a failure of a Lipschitz nonlinear multi-agent system,fault estimation observers are designed in the entire frequency domain and the finite frequency domain,respectively.First,according to the relationship of information transfer between agents in the directional communication topology,the relative output estimation error is defined,an adaptive fault estimation observer is designed and the observer error system is obtained by combining the state equation of the original system,the pole assignment method is used to configure the poles of the observer error system in a certain disk area.Then,in the process of using the Lyapunov method and the matrix inequality method to deduce theH_?performance index condition of the entire frequency fault estimation observer,the sufficient conditions for satisfying theH_?performance index are obtained by using the related properties of the Lipschitz function and combining with the Schur complement lemma.Secondly,considering that the external disturbance and fault signal is often in the finite frequency domain,the sufficient conditions for satisfying the robust performance index in the finite frequency domain are obtained according to the defined performance index of the finite frequency domainH_?and the correlation properties of the trace.Finally,the simulation results show that the finite frequency domain fault estimation observer has a better robust performance index than the entire frequency domain fault estimation observer,and the conservatism of the design can be reduced.(2)For the failure of the active suspension LPV system actuator,the problem of robust reliability state feedback controller design is studied in the finite frequency domain.First,the active suspension system model is established considering the change of damping coefficient.Then,according to generalized-Kalman-Yakubovich-Popov(GKYP)Lemma and Projection Lemma,stability conditions and robustness conditions of the state feedback controller are obtained.This condition can guarantee the active suspension system to meet the robust performance index in the finite frequency domain,and the system can run stably no matter whether the actuator fails or not.Finally,the effectiveness of the designed robust reliability state feedback controller is verified by Matlab simulation.