The Condition Detection And Fault Diagnosis Of Position And Speed Measurement System For High Speed Maglev Train

In this paper,the state detection and fault diagnosis of high-speed maglev train positioning and speed measuring system are studied,and the failure mechanism of the common faults of the positioning and speed measuring system is analyzed based on the working principle of the positioning and speed measuring system.Aiming at the problems of state detection and fault diagnosis of relative position sensor,absolute position sensor and signal processing cabinet,theoretical analysis and method verification are carried out,and the fault diagnosis function of positioning and velocity measurement system is realized.The main contents of the paper are as follows:1、Based on the analysis of signal processing flow of positioning and velocity measurement system,the failure mechanism of relative position sensor,absolute position sensor and signal processing cabinet is analyzed,and the parameter normalization standard is proposed according to the setting of absolute position sensor receiver circuit comparator.2、Aiming at the common faults of positioning and velocity measurement system,the state detection point is selected and the state detection circuit is designed,which made the extraction of the fault features is realized.According to the on-line operation condition of the positioning and velocity measurement system,a real-time diagnosis scheme for the transmitting circuit of absolute positioning sensor based on counter and a real-time detection scheme for leakage and error code faults are proposed.And a realtime detection scheme based on finite state machine for the leakage or error of absolute positioning sensor reading code is proposed.3、The fault characteristics of the relative position sensor are analyzed,and the arcsine method is proposed to extract the phase characteristics.The on-line condition monitoring method for relative position sensor and absolute position sensor is designed,and the real-time diagnosis circuit for relative position sensor is designed.4、The characteristic states of sensors in normal and fault states are acquired by simulating common faults of sensors.The fault diagnosis decision trees of relative positioning sensor and absolute positioning sensor are established by training the acquired data,and the diagnosis effect is verified by the test set.The combination of support vector machine and decision tree improves the accuracy of fault diagnosis,which makes up for the poor diagnosis effect of the relative positioning sensor decision tree5、The off-line diagnosis platform of high-speed maglev train positioning and speed measurement system is designed,and the on-line detection program of the system is realized.The hardware platform of the off-line detection platform of the positioning and speed measurement system is built.The state detection and fault diagnosis scheme proposed in this paper can provide a reference for engineering application to meet the requirements of engineering application of positioning and speed measurement system.