Study On Stabilization Control Design For Switched Systems:A Bumpless Transfer Control Method

Being a class of important and special hybrid systems,switched systems have attracted lots of attention due to their great significance in theory and wide backgrounds in practice.In recent years,switched systems have gained numerous results which find many applications.Most of the theoretical results for switched systems focus on steady-steady properties of systems,paying less attention to transient performances,especially those caused by switchings.Switchings bring both advantages and disadvantages for the study of switched systems.The advantages of switchings mainly lie in the design of switching laws by which switched systems can satisfy the properties which are not shared by subsystems.Transient behaviors resulting from switchings are the main disadvantages of switchings.Bumps in the system signals may arise whenever a switching happens,which may bring unfavorable consequences,such as the performance degradation and even instability.Therefore,it is essential to suppress the bumps in the signals at switching instants.Bumpless transfer control is an effective control strategy to suppress the chattering in the signals caused by switchings.Recently,however,in the study of switched systems,the results on the control problems for switched systems solved by bumpless transfer control schemes are quite limited.Many problems are far from being understood and thus deserve investigations.Based on the bumpless transfer control method,this dissertation studies stabilization problems for switched systems including the output regulation,tracking,filtering,event triggering,fault estimation,tolerant and so on.The main results of this dissertation are summarized as follows:(1)The output bumpless transfer control problem for a class of switched controller systems is studied.By modifying the pre-designed controllers and designing a switching law,the result on the output bumpless transfer control for the switched controller systems with one switching is generalized to the general switched controller systems with multiple and even infinite switchings,while maintaining the almost output regulation property of the switched controller systems,solving the conflict in the requirements on the almost output regulation property and the output bumpless transfer performance.(2)The input bumpless transfer control problem for switched linear systems to achieve output tracking is investigated.Based on the multiple Lyapunov functions approach,three sufficient conditions for the H? output tracking property and the input bumpless transfer performance,the H? state tracking property and the input bumpless transfer performance and the almost output regulation property and the input bumpless transfer performance are established,respectively.Under these conditions,the conflict in the requirements on each output tracking property and the bumpless transfer performance is solved,and the assumptions on the positiveness of the Lyapunov functions and the solvability on the almost output regulation problem for subsystems are relaxed.(3)The input bumpless transfer control issue for a class of switched linear systems with the H? filtering property is studied.First,a new description on the input bumpless transfer performance is proposed,limiting the magnitude of the control bumps only at switching instants.This description improves the existing ones which require the limitation on the control signal during the active time interval of subsystems.Then,by virtue of the multiple Lyapunov functions method,a set of filters,filtering-based controllers and a switching law are jointly designed to solve the problem of the input bumpless transfer control for the switched linear systems with the H? filtering property.(4)The problem of the input bumpless transfer control for two classes of constrained switched systems is investigated.First,for switched positive linear systems,two different input bumpless transfer control strategies with the L1-gain property are proposed.Second,for the switched systems with state and rate constraints,a definition on the bumpless transfer performance for the actuator with possible failures is given,an analysis on the disturbance tolerance ability with the bumpless transfer performance ensured is made,and a H? reliable input bumpless transfer control scheme is established.(5)The input bumpless transfer control issue for a class of switched T-S fuzzy systems is studied.A description on the bumpless transfer performance under the T-S fuzzy reasoning rules is given.A solvability condition on the bumpless transfer control problem for the switched T-S fuzzy systems with the L2-gain property is developed via the design of a set of controllers and a switching law.The established condition includes that obtained by the classical multiple Lyapunov functions method as a special case.(6)The issue of the event-triggered input bumpless transfer control for a class of switched linear systems is investigated.By joint-design of an event-triggered mechanism,a group of event-driven controllers and a switching law,the control bumps at switching instants and triggering instants are suppressed,the stability of the system is ensured,and the Zeno behavior is excluded.What should be highlighted is that with the designed switching law,not only a minimal dwell time of subsystems is guaranteed,but also the increase of the Lyapunov function of each subsystem during its minimal dwell time interval is allowed,which reduces the conservativeness of the condition on the switching law.(7)The fault estimation and tolerant bumpless transfer control problem for a class of switched linear systems is studied.A solvability condition on the problem is given by design of a switched intermediate estimator,a switched bumpless tolerant controller and a switching law.The designed estimator is an improvement of that in non-switched systems.Under the designed estimator,the assumption on the observer matching condition in the fault estimation problem of switched systems is relaxed.Also,the condition on the switching law is less conservative than the traditional ones.(8)The problem of the rate bumpless transfer control for a class of switched linear systems is proposed.A description on the rate bumpless transfer performance is proposed.By the multiple Lyapunov functions approach,a control strategy ensuring the rate bumpless transfer performance and the stability of the systems is established,solving the conflict requirements on the rate bumpless transfer performance and the stability.An experiment study on the aero-engine is implemented,showing the effectiveness and applicability of the established rate control scheme.