Condition Monitoring And Fault Diagnosis Of Reliability Test Process Of Raster Line Displacement Sensor

The grating line displacement sensor is used for the position feedback link in the closed-loop control of CNC machine tools.It is the key component of the position measurement of CNC machine tools.However,domestic CNC machine tool manufacturers use imported products because of the lack of reliability of domestic grating line displacement sensors when manufacturing CNC machine tools.Based on this,the subject research on the reliability of domestic grating line displacement sensors.This paper focuses on the reliability test state monitoring and fault diagnosis technology of grating line displacement sensor,which is helpful to grasp the state change trend of grating line displacement sensor,provide reference for the maintenance of grating line displacement sensor,and the reliability test of grating line displacement sensor.The improvement of the level of system automation is of great significance.In this paper,the incremental closed grating line displacement sensor is taken as the research object.Firstly,the fault tree is analyzed and its common fault and fault characterization signals are found.Based on this,the software and hardware environment is built and the raster line displacement sensor based on Lab VIEW is developed.The reliability test condition monitoring system is proposed.The method of feature value extraction for fault characterization signal is proposed.The GA-SVM algorithm is used to realize fault diagnosis.The feasibility of the proposed method is verified by experimental data.The main research contents of this paper are as follows:1.Failure mechanism analysis of grating line displacement sensor.The working principle and mechanical structure of the grating line displacement sensor are introduced.Based on this,the fault tree analysis method is used to find the fault cause of the common fault mode of the grating line displacement sensor,which lays a foundation for constructing the grating line displacement sensor condition monitoring system.2.The grating line displacement sensor condition monitoring system is established.Determine the monitoring signal of the grating line displacement sensor condition monitoring system.On this basis,complete the hardware configuration and sensor configuration of the acquisition system;briefly introduce the virtual instrument technology,and select Lab VIEW as the software development environment to complete the signal display,analysis,and the software program is stored and queried,and each module is introduced in detail.3.Research on fault diagnosis method of grating line displacement sensor.The signal eigenvalue extraction method of the grating line displacement sensor is introduced.Firstly,the wavelet threshold denoising is introduced.Then the CEEMD algorithm is used to modally decompose the vibration signal,and then the signal eigenvalues are extracted from the time domain,the frequency domain and the information entropy respectively.Finally,the GA-SVM algorithm is introduced,and the GA-SVM algorithm is used to complete the fault diagnosis.4.Experimental application of grating line displacement sensor fault diagnosis technology.Using the fault diagnosis method proposed above,the experimental data is used for verification.Firstly determine the five most common states of the grating line displacement sensor-normal state,chip contamination state,spring off state,loose bearing state,cutting fluid contamination state,experiment with each state and collect 60 sets of data,vibration signal Wavelet threshold denoising and CEEMD decomposition are performed,and effective IMF components are extracted.The time domain eigenvalues,frequency domain eigenvalues and information entropy values of effective IMF components and voltage signals are extracted and the eigenvectors are constructed.The GA-SVM algorithm is used to construct the diagnostic model.75% of the data is used for training models and 25% is used for training models.Test,get Accuracy to 100%,verify the feasibility of the troubleshooting method proposed in this paper.