Research On Robust Control And Filtering Methods For Neutral Switched Systems

Neutral switching systems represent a widely existing system in practical engineering,such as lossless power transmission systems,ship balance control systems,aircraft power systems,etc.Due to its important theoretical research value and extensive engineering application background,it has received widespread attention from experts and scholars.However,due to the existence of neutral delay and the switching characteristics of the system,the stability analysis and controller/filter design of the system become more difficult.Therefore,it is of great significance to study stability analysis methods for neutral switching systems,weaken the constraints of related results,and seek less conservative stabilization results.This article uses time-dependent Lyapunov functionals and modal dependent Lyapunov functionals,combined with ADT and MDADT methods,to study the analysis and synthesis problems of systems under different switching rules.At the same time,it considers various interval time-varying delays,system uncertainty,system state unmeasurable,asynchronous switching,and other issues.The main research content includes the following aspects:First,for a switched neutral system with interval time-varying,the design problems of non-fragile robust H∞ feedback controllers and dynamic output feedback controllers are studied.Among them,Chapter 2 describes the system uncertainty and the controller with gain perturbation by introducing norm-bounded uncertainty.Based on the Lyapunov stability theory and combined with the average dwell time switching method(ADT),the robust nonfragile controller design approach under H∞ performance constraints are studied.Chapter 3considers that in the actual controller design process,it is usually impossible to obtain the complete information of state variables for feedback control,and proposes a dynamic output feedback controller design method.By selecting the delay-dependent Lyapunov functional and introducing the relaxation matrix,the closed-loop system exponential stability condition and controller gain expression are obtained.The effectiveness and low conservatism of the design method are verified in the simulation example.Secondly,further considering the mismatch between the controller/filter mode and the system mode in the actual switching,that is,the asynchronous switching phenomenon.Therefore,the robust H∞ control/filtering problem based on mode-dependent average dwell time(MDADT)switching rule is studied for switched neutral systems.Chapter 4 presents a design method of robust H∞ controller for an uncertain neutral switching system in the case of asynchronous switching.Based on the Lyapunov stability theory,a modal-dependent Lyapunov-Krasovskii functional is constructed for the asynchronous phase and the synchronous phase,combined with the MDADT method to study the stability analysis of the system,and a set of LMIs are obtained to ensure that the closed-loop system is exponentially stable and sufficient conditions with H∞ performance criteria.Chapter 5 is aimed at the filtering error system under the asynchronous stage,using the MDADT method and the piecewise Lyapunov function technology,applying the projection theorem to deal with the product term between the Lyapunov-Krasovskii functional and the system matrix.The explicit expression of the filter in the asynchronous stage is given,and the parallel result under the synchronous switching is also obtained.Finally,the effectiveness of the method is verified by a simulation example.Finally,Chapter 6 proposes an event-triggered communication mechanism and investigates observer-based output feedback control for neutral switched systems with mixed time-varying delays.It is worth noting that under the proposed event-triggered mechanism,asynchronous switching problems may arise between the subsystem and its matched subcontroller.By analyzing the relationship between system switching time and event triggering time,based on the Lyapunov stability theory and related lemmas,sufficient condition to ensure the exponential stability of the closed-loop system is obtained.Further,the controller solving problem is transformed into a convex optimization problem by congruent change and variable substitution.The validity of the method is illustrated by an example.