Study On Adaptive Control Of Switched Cyper-physical Systems Under Actuator Attacks

Switched cyper-physical system integrates computing,network,physical process and multi-mode integration.Due to the rapid development of computing and communication technology,cyper-physical system has been widely used in various engineering fields.Because of the openness of wireless communication,switched cyper-physical systems are vulnerable to network attacks,which will affect the data transmission between each subsystem,thereby affecting the operation and performance of switched cyber-physical system,even endanger the security of the switched cyber-physical system.Therefore,the security of switched cyper-physical systems have been paid much attention.When switched cyper-physical systems are attacked by the network,how to design the controller and the switched signal which still make the system stable is extremely important.In response to the above problems,this thesis mainly studies the stability of the switched cyper-physical system when the actuators are attacked by different forms of network attacks.In view of different forms of network attacks,setting up the mathematical modeling of attack signals,and designing corresponding adaptive controllers and switched signals to guarantee the stabilty of the switched cyper-physical systems.The main work is as follows:(1)According to the structure block diagram of the information about cyper-physical systems and attack signals,setting up the modles for the switched cyper-physical systems and attack signals respectively.Since the attack signals are unknown,it needs to be built as an attack signal with unknown constant parameter items and time-varying parameter items.(2)The stability of a single input switched cyper-physical system is studied under attack signals with unknown constant parameters.For the unknown constant parameter attack signal,Firstly,an adaptive controller is designed for each subsystem according to offset the impact of unknown attack signals on the system.And a switching signal with the average dwell time constraint is designed for the closed-loop multiple Lyapunov function methods.Then,proving the stability of the switched cyper-physical systems which used multiple Lyapunov function methods.Finally,a simulation example is presented to verify the validity of the proposed method.(3)The stability of a multi input switched cyper-physical system is investigated under attack signals with unknown time varing parameters.Firstly,according to the mathematical model of attack signals and switched cyper-physical system,designing an adaptive controller for each subsystem.And looking for a switching signals with the average dwell time constraint which can ensure the stability of the system.Then,giving the stability stability analysis with the help of the multi-Lyapunov function method for the uncertain multi input switched cyper-physical system.At last,the feasibility of the proposed method is iullstrated by a simulation example.