On Stability Of Switched Systems In The Presence Of Actuator Saturation

Switched systems are important hybrid systems which are composed of a family of continuous-time or discrete-time subsystems and a rule orchestrating the switches among them.Switched systems have wide application in complex industrial processes that contain multiple motion modes.Switched systems possess significant theoretical value and practical meaning.Actuator saturation is an inevitable phenomenon in many practical switched control systems.This nonlinearity may cause performance degradation and sometimes even instability of a control system.The stabilization problem for a class of switched systems with actuator saturation is investigated in this thesis.The main contents are listed below:First,an observer-based feedback stabilization of switched systems with actuator saturation is studied.When the state of the system is not available for measurement,the Luenberger type state observer is designed.Then we can obtain a new closed-loop system under an estimated state feedback.By employing the sector bound nonlinearity to handle the saturation effect,the average dwell time approach is utilized to derive the stability criteria of the closed-loop system.Second,a novel approach to the estimation of domain of attraction for switched systems with actuator saturation is presented.Due to the increase of the number of decision variables,a sufficient condition is provided with less conservativeness comparing with those obtained by linear differential inclusion.We propose the average dwell time approach to guarantee the exponential stability of the closed-loop system.Thus the estimation of the domain of attraction is enlarged.Finally,for switched systems with actuator saturation,we make a co-design methodology of event-triggered mechanism and the switching law with average dwell time.The result can guarantee the stability of the closed-loop system,and reduce the transmission of information.The communication resources can be saved.At the same time,in order to avoid Zeno phenomenon,the minimum triggering interval is calculated.