Research On Optimal Configuration Methods Of Contact R-test Based On Performance Requirements

R-test is a special precision instrument for measuring the structural error and dynamic error of the rotary axis of five-axis machine tools.It is widely used in the field of error measurement of machine tool axis due to its high precision and convenient operation.To further improve the measuring performance optimization method of the R-test,the measuring model of the Rtest,analysis of the factors affecting performance,hardware configuration and performance evaluation method for the contact R-test are studied in this thesis.Based on the certain measuring performance requirements,the hardware parameter configuration of the contact Rtest and the design and development of the prototype are realized respectively,the measuring performance evaluation of the prototype is completed and the on-machine error measurement experiment verifications are completed.The main research works are as follows:(1)According to the structure and measuring principle of the contact R-test measuring instrument,the point vector theoretical measuring model is established and the calibration and solution method are determined,and the main influence error factors of the measuring instrument’s measuring performance are analyzed to establish the actual measuring model.(2)The performance indicators of the R-test are defined and the corresponding performance evaluation models are established.And the sensitivity analysis and uncertainty evaluation of the error source in the calibration process is completed respectively and based on the Guide to the Expression Uncertainty in Measurement and the Monte Carlo Method to accomplish precise prediction and evaluation of the measuring space of the R-test.(3)Based on the measuring performance evaluation models,the methods for the optimal configuration of the hardware parameters of the measuring instrument are proposed.The hardware geometric parameters and accuracy parameters of the measuring instrument are configured according to specific measuring requirements,to realize a customized design of the R-test.(4)The type of hardware of the R-test is determined based on the above hardware configuration methods.The measuring performance indexes of the prototype are evaluated based on the performance evaluation methods,and the evaluation results are compared with the actual calibration results on the Coordinate Measuring Machine(CMM).The experimental comparison results show that the planar contact R-test measuring instrument developed based on the above hardware parameter optimal configuration method meets the proposed measuring requirements,and the performance evaluation method is effective.(5)The developed R-test prototype is used to complete the error measurement and compensation for the rotary axes on different types of five-axis machine tools.The experimental results show that the error identification and compensation effect is remarkable and once again show that the hardware parameter configuration method is feasible.