Research On Sliding Mode Control And Application Of Uncertain Switching Systems Based On State Estimation

Switched systems,as a peculiar class of hybrid systems,are composed of different subsystems and the switching signal that stipulates which subsystem will be activated.In recent years,the switched systems have aroused wide attention,which can be attributed to two practical purposes: Firstly,switched systems provide a united framework for the mathematical modeling of physical systems such as aerospace control systems,manipulator control systems and networked control systems.Secondly,such plants with the switching between multiple controllers provide an efficient mechanism for dealing with systems with uncertainties and high complexities.However,the complexity of the switched systems is not merely the superposition of the properties of each subsystem,due to the existence of the switching signal,it may even have properties completely different from those subsystems.Sliding mode control(SMC)has been utilized to stochastic systems,time-delay systems and uncertain systems in view of its advantages of quick response,low sensitivity to parameter variations and perturbations.Moreover,SMC provides by itself discontinuous control laws and has been considered as an effective control strategy for regulating the switched systems.Up to now,although some works have applied SMC to the analysis and synthesis of switched systems,most of them are assumed that the state variables are available.However,due to the complexity of the actual systems,the limitation of the sensor measurement and the cost budget,the state variables may be difficult to be obtained.On the basis of the previous achievements,this paper is further focused on the problem of the adaptive SMC of the uncertain switched systems based on the state estimation.The details are listed as follows:1.A state-estimation-based adaptive sliding mode controller design scheme is proposed for a class of uncertain switched systems.A state observer is utilized to estimate the unknown state variables,from which a novel sliding surface scheme is presented.On the basis of linear matrix inequality technique,the average dwell time approach and Lyapunov stability theory,exponential stability of the overall switched system is ensured by virtue of the proposed control scheme.An adaptive reaching motion control law is then developed to ensure the state trajectory can be driven onto the designated sliding surface in finite time.At last,the validity of the proposed control strategy is demonstrated by simulation results.2.This part is devoted to the exponential stabilization problem of time-varying delay switched systems with nonlinear uncertainties via sliding mode technique.A non-fragile observer which can tolerate the existence of the uncertainties in state estimator is established to deal with the case that the partial or total measurement of the state variables is unavailable,from which a new integral sliding manifold scheme is provided.An exponential stability criteria of the dynamics in sliding mode phase is then devised in accordance with the Lyapunov stability theory,linear matrix inequality technique and average dwell time method,and then the arrival condition of the designated sliding manifold is satisfied by utilizing the developed adaptive sliding mode controller.At last,the feasibility of the proposed control scheme is confirmed through illustrative examples.3.For the uncertain switched system model which is considered in research content1,a non-fragile state observer is provided,and a new single linear sliding manifold scheme is proposed.A new technical approach of the underlying system analysis and realization during the sliding mode phase is exploited based on the designed sliding manifold.An associated adaptive switching controller synthesis is further presented,by which the arrival condition in finite-time of the designated sliding manifold is fulfilled.Ultimately,illustrative examples are conducted to confirm the superiority and feasibility of the proposed scheme.