Optimization of measuring points based on the grey system theory for spindle of CNC machine tool

To analyze the thermal error of spindle, the grey correlation analysis method is used to optimize the thermal key points to build the model of temperature field on the basis of temperature measurement experiment. By optimizing, the number of temperature measuring points sinks from 8 to 3. It greatly reduces the time for variable searching and modeling and meanwhile it eliminates the coupling problems among temperature variables. In this way, the precision of thermal error model and thermal error prediction can be improved.