Output Feedback Control Of A Class Of Nonlinear Switched Systems Based On Incomplete Measurement

In recent years,switched systems have been used more and more widely in real life,so experts are more interested in switched systems.A switched system is composed of different subsystems and a set of switching rules that determine how subsystems switch.It can be seen that the switched system is not only related to different subsystems,but also restricted by the switched rules.At present,the stability of switched systems is still a hot research direction.In the process of data transmission,there will be packet loss,channel or device saturation and other abnormal conditions,which will affect the stability of the switched system.In this thesis,the controller is designed by using backstepping method based on the design of appropriate state observer under abnormal conditions such as data packet loss,channel or device saturation,so that the system can also be probabilistic stable under abnormal conditions.Firstly,the research background and significance of switched systems are introduced,including the definition and basic model of switched systems.Some preliminary knowledge,such as backstepping,neural network,Lyapunov stability and other theoretical knowledge applied in the following analysis are briefly introduced.Secondly,the output feedback control of nonlinear switched strict feedback systems based on incomplete measurement is studied.Under normal data transmission conditions and abnormal conditions such as data packet loss,channel or device saturation during data transmission,the analysis shall be carried out respectively.Since the state of the system is unknown,the state observer is designed first,and then the control law is designed by using the backstepping method,which can ensure that all closed-loop signals remain bounded under a class of switching signals with average dwell time.Probabilistic stability analysis is carried out to ensure that all signals in the system can be uniformly ultimately bounded.Finally,a simulation example is used to prove the effectiveness of the design.Finally,the output feedback control of nonlinear switched pure feedback systems based on incomplete measurement is studied.First,the mean value theorem is used to transform the pure feedback system.Secondly,when the data transmission is normal and the data transmission is abnormal,the state observer is designed respectively,and then the control law is designed using the backstepping method,so that all closed-loop signals can be kept bounded under a class of switching signals with average dwell time.With the help of Shure complement theorem,the difficult nonlinear matrix inequality problem can be transformed into a linear matrix inequality problem,and then the conditions for the probabilistic stability of the state observer and the closed loop system are obtained to ensure that the designed control method can make all signals in the system uniformly ultimately bounded.In the end,a simulation example shows that the designed control method is effective.