Dissipativity Theory-based Output Regulation And Robust Control For Switched Nonlinear Systems

As an important and special class of hybrid systems,switched control systems have been attracting much attention in the control area,due to many engineering applications of switched systems.On the other hand,dissipativity,especially passivity,is a very useful system property which offers an effective tool for the analysis and design of non-switched systems.For switched systems,the dissipativity property is still expected to be useful.For switched nonlinear systems,the study on dissipativity is just at the early stage.Especially for uncertain switched nonlinear systems,many problems have not been solved and thus deserve investigation.This dissertation studies the dissipativity property,stability property and a few synthesis issues including stabilization,disturbance rejection,output regulation for several classes of switched nonlinear systems by using multiple storage functions.The main contributions are as follows.1.The issues of robust passivity,feedback passification and global stabilization are studied for a class of switched nonlinear systems with structural uncertainty.Firstly,a concept of robust passivity is proposed for uncertain switched nonlinear systems.Secondly,a sufficient condition for such a system to be robust passive without the requirement of robust passivity property of subsystems is obtained by the design of a state-dependent switching law.Secondly,a state-dependent switching law and state feedback controllers are designed to render the resulting closed-loop system robust passive.Finally,a robust strictly passive system is shown to be stabilized.Then,a recursive feedback passification design technique is developed to achieve the global stabilization problem when the subsystems have any uniform vector relative degree.2.The adaptive passification,global stabilization and disturbance attenuation problems for a class of switched nonlinearly parameterized systems are investigated.The first part studies the issues of adaptive passification and global stabilization.Firstly,a passivity concept for switched nonlinear systems is proposed.In particular,the change of storage functions of an inactive subsystem is described.An adaptively feedback passive switched nonlinear system is shown to be stabilized under the partly asymptotic zero-state detectability assumption.Secondly,the adaptive feedback controller for each subsystem and a state-dependent switching law are designed to render the resulting closed-loop system passive.Finally,a new switched adaptive control technique is developed to solve the adaptive stabilization problem by exploiting the recursive feedback passification design technique and parameter separation technique when all subsystems have any same relative degree.The second part investigates the adaptive feedback passification and disturbance attenuation problems.First,a state-dependent switching law and a set of adaptive feedback controllers with new control inputs are designed to render the resulting closed-loop system passive for a class of switched nonlinearly parameterized systems without external disturbance.Then,the new control inputs are designed to solve the disturbance attenuation problem.Second,a set of adaptive feedback controllers and a composite state-dependent switching law are designed to solve the adaptive feedback passivity-based disturbance attenuation problem for a class of cascaded switched nonlinearly parameterized systems.3.The adaptive quasi-passification-based stabilization problem for a class of switched nonlinearly parameterized systems is investigated via average dwell time method.Firstly,a notion of global practical stability of a switched nonlinear system is proposed.At least a subsystem is required to be quasi-passive,the global practical stability of the resulting closed-loop system is obtained by the design of the controller for each subsystem under the average dwell time.Secondly,when the subsystems have any relative degree,a new switched adaptive control technique for stabilization problem is developed to achieve global practical stability by exploiting the recursive feedback passification design technique and parameter separation technique.The states and parameter estimation errors converge to the ball whose sizes can be reduced by choosing appropriate design parameter.Finnally,when the system states are not measurable,the adaptive output feedback quasi-passivity-based stabilization problem is solved.The proposed output feedback controllers do not dependent on any state observer.4.The incremental(Q,S,R)-dissipativity and incremental stability for switched nonlinear systems are considered without the requirement of incremental(Q,S,R)-dissipativity of subsystems.Firstly,an incremental(Q,S,R)-dissipativity concept is proposed for switched nonlinear systems.We show that an incrementally(Q,S,R)-dissipative switched nonlinear system is incrementally stable.Secondly,the sufficient conditions to be incrementally(Q,S,R)-dissipative for switched nonlinear systems are given by the design of the state-dependent switching laws.Finally,this incremental(Q,S,R)-dissipativity property is shown to be invariant under compatible feedback interconnection by the design of a composite state-dependent switching law.5.Incremental passivity and the incremental passivity-based output regulation problem of switched nonlinear systems are addressed.The first part solves the output regulation problem using incremental passivity concept via average dwell time method.At least a subsystem of such a switched system is required to be feedback incrementally passive.First of all,we solve the output regulation problem via full information feedback.Then,the dynamic error-feedback controllers and a switched internal model whose subsystems are incrementally passive are designed to solve the error feedback output regulation problem.The second part studies the problems of incremental passivity,feedback incremental passification and global output regulation for a class of switched nonlinear systems without the requirement of incremental passivity of subsystems.A more general concept of incremental passivity for switched systems is proposed.Firstly,a sufficient condition for switched nonlinear systems to be incrementally passive is given by the design of a state-dependent switching law.Secondly,a state-dependent switching law and a set of state feedback controllers are designed to render the resulting closed-loop system incrementally passive.Finally,we show that once the incremental passivity is assured for switched nonlinear system,the output regulation problem is solvable,even though the problem for none of subsystems is solvable.The conclusions and perspectives are presented in the end of the thesis.