Current-based feed axis condition monitoring and fault diagnosis

Abstract

A kind of numerical control machine tool feed axis condition monitoring system based on AC servo motor current is proposed. Firstly, the mathematical model between motor current and the fault is established. Then the test principle is profoundly investigated. And the frequency response between the disturbance torque from the fault and motor current is analyzed based on Matlab/SIMULINK. To obtain the motor current information, some different measured methods are suggested. In addition, the wavelet transform technology is proposed to detect the fault. The analysis results of the simulation and experiments show that it is feasible and reliable to use the motor current for monitoring the mechanical parts state, which puts basis for online feed axis condition monitoring and localizing the fault source rapidly. © 2009 IEEE.