Fault-tolerant Control Of Networked Control Systems With Delay And Packet Loss

NCSs are widely used in many fields,such as remote surgery,unmanned aerial vehicle and automated highway system.However,compared with the traditional control system,the network will inevitably bring some problems,such as signal transmission delay and packet loss,etc.At the same time,the actuator and sensor nodes need deal with many complex control tasks,which can cause failure easily,so that it will affect the stability of system.Therefore,fault-tolerant control of NCSs has strong theoretical research value and realistic background.(1)The research background,purpose and significance of this article are introduced.At the same time,this chapter briefly introduced several basic problems and some related knowledge of NCSs.(2)The fault-tolerant control problem of long delay NCSs with packet loss sensorcontroller is studied.In the conditions of having external disturbance vector or not,the fault-tolerant controllers of NCSs are designed respectively when the actuators are failed.NCSs By introducing a class of random switching matrix,an augmented model of long delay NCSs with packet loss and stochastic external disturbance vector is established.Next,combined with?H control theory,the appropriate Lyapunov function is constructed.The state feedback controller can be solved by matrix inequality and the sufficient conditions for asymptotic stability of the system are given.Finally,the feasibility and effectiveness of the conclusion are verified by simulation results.(3)The fault-tolerant control problem for long delays NCSs with bilateral arbitrarily packet loss or bilateral random packet loss is studied,respectively.The packet loss process between the sensor-controller link and the controller-actuator link is modeled as two random switches and a homogeneous Markov chain with two states,respectively.By constructing an appropriate Lyapunov function,the state feedback controller can be designed and the sufficient conditions for stability of the closed-loop system are given,whether the actuator is abnormal or not.The simulation examples are given to illustrate the feasibility of the proposed method.(4)The fault-tolerant control problem of long delay NCSs with uncertain modeling factors is studied.With the effect of packet loss between sensor-controller,the uncertain augmented model of NCSs with uncertain state is established by introducing the matrices of sensor arbitrary fault.Based on Lyapunov method and H?control theory,the sufficient conditions for the system with integrity against sensor fault and robustness against uncertain factors are given.The proposed approach efficiency are verified by simulation results.(5)The work of this paper is summarized and the prospect of future research is made.