Research On Optimization Design Of Contact R-test And Measurement Technology Of Rotating Axis Structural Error

The geometric errors of a five-axis machine tool’s rotating axis include structural errors and motion errors.Among them,structural errors have a significant impact on the machining accuracy of the machine tool,but there are few studies on their measurement methods.To this end,this paper studies the methods of structural optimization,on-machine calibration,spherical center coordinate solution and rotating axis structural error identification of the spherical probe contact R-test,and the development and application verification of the prototype are carried out.This research further expands the relevant measurement and application technology of the R-test measuring instrument,and realizes the convenient measurement of the rotating axis structural error of five-axis machine tool.The main tasks are as follows:Firstly,two types of contact R-test structural design schemes using inclined probes and spherical probes are proposed.By analyzing and comparing the measurement principles and accuracy of the two,the spherical probe contact R-test scheme is selected.With the objective of maximizing measurement stability and maximizing measurement space,the structural parameter optimization method of the spherical probe contact R-test is studied.Secondly,the on-machine calibration method of measuring coordinate system and sensor position of a spherical probe contact R-test measuring instrument is studied,and a sensor position calibration model is established;According to the calibrated sensor position,a spherical center coordinate solution model in the measuring coordinate system is established.Both the sensor position calibration model and the spherical center coordinate solution model are optimized using the self-adaptive differential evolution algorithm(Sa DE).Then,the spherical center coordinates are converted into the displacement error data under the ideal measuring coordinate system,and the rotating axis structural error is identified by the least square circle fitting method and the straight line fitting method according to a set of displacement error data.On this basis,the identification method of rotating axis dynamic geometric error is further discussed;Finally,a prototype of the spherical probe contact R-test measuring instrument and its supporting rotating axis structural error measurement software are developed.Simultaneously,the spherical center coordinate solution accuracy and the structural error identification effect of the R-test measuring instrument are verified on a DMU100 mono BLOCK~?five-axis machine tool.The experimental results show that the spherical probe contact R-test measuring instrument has high spherical center coordinate resolution accuracy and good structural error identification effect,which can provide an effective reference for industrial measurement and improve the machining accuracy of five-axis machine tools.