Sensor Fault Diagnosis And Fault-tolerant Control Of First-order Servo System Based On Dynamic Trend

The application space of servo control system in industrial automation is more and more extensive,and the research of sensor fault diagnosis technology is an important demand in practical engineering.In this paper,a static model of fault diagnosis and a fault-tolerant control algorithm based on dynamic trend are constructed,and the validity and high accuracy of the method are verified by experiments.The main work is as follows:(1)This paper summarizes the existing research methods in this field at home and abroad,including three kinds of fault diagnosis technology and two kinds of fault-tolerant control technology;analyze the advantages and disadvantages of the existing methods in different angles,put forward the problems still to be solved,and the advantages of sensor fault diagnosis and fault-tolerant control based on dynamic trend are expounded..(2)Based on PLC and MATLAB/Simulink technology,a first-order liquid level object experiment platform is built,and the data acquisition method for normal system and sensor fault system under the condition of servo signal input is determined.(3)The sensor fault diagnosis model and fault-tolerant control algorithm of the first-order servo system are proposed.A data processing model based on sliding window is designed.The fault is isolated in the window,and the fault size is calculated by the adaptive threshold binarization method.Next,the analytical model of fault characterization is obtained by the linear regression method;according to the analysis of fault diagnosis results,a fault-tolerant control algorithm based on dynamic trend is proposed to counteract the influence of fault.(4)The diagnosis method and fault-tolerant control method for on-line application are proposed.Based on the "innovation platform of fault diagnosis and fault-tolerant control" of OPC communication technology,the static model of sensor fault diagnosis of first-order servo system based on dynamic trend is calibrated.The high accuracy of fault diagnosis and the effectiveness of fault-tolerant control method are verified by on-line simulation.