Fault Detection And Fault Tolerant Control In NCS Based On Delta Operator

Network Control Systems(NCS)work as the feedback control system to achieve information sharing and transferring through the medium—network.As the unified description form between discrete control systems and unified control systems,Delta operator method can be applied to NCS fault detection and fault-tolerant control.In comparison with the conventional discrete gression operator method,Delta operator method will better solve problems like numerical value's instability and augmentation of residual error caused by the conventional discrete gression operator in the situation of high frequent sampling.This thesis analyzed that the problems of fault detection and fault tolerant control occur in NCS based on Delta operator,which will make Delta operator become full of scientific and academic value in the research of fault detection and fault tolerant.Researches that this essay concentrates on are as follows:1)The fault diagnosis problem of NCS based on Delta operator was researched,the devise method of NCS fault detection filter based on Delta operator was provided.First of all,put all devise problems of NCS fault detection filter which is random time delay and norm bounded down to the problem of solve H? filter;second,get H? filter's optimum solution through building lyapunov function and converted by LMI(Linear Matrix Inequalities).This solution not only can guarantee the input of norm bounded and the robust time delay of network control system,also ensure the sensitivity of residual error to fault signals.Finally,prove this method is valid through data simulation.2)The problem of fault-tolerant control based on Delta operator's uncertain time delay was researched.Firstly,provide the model of NCS's uncertain time delay described by Delta operator.Secondly,assume in the situation of sensor or actuator partial failure,according to the design theory of fault-tolerant controller,this fault-tolerant controller can apply the combination of lyapunov function and LMI to design the fault-tolerant controller of this system.This research indicates this fault-tolerant controller can guarantee the stability of system operation.3)The problem of NCS's fault-tolerant control based on Delta operator's packet loss was researched.This thesis built the packet loss NCS based on Delta operator,and applied the combination of lyapunov function and LMI to devise the closed loop fault-tolerant controller in the situation of the sensor or actuator partial failure in this packet loss NCS,which will help to keep closed loop system operation stable.And the validity of this method has been proved through simulation experiment.