Measurement Method Of Guideway Motion Error And Analysis Of Equipment Space Error

The guide rail is an indispensable part of the CNC machine tool.It has six motion errors(horizontal straightness,vertical straightness,positioning,yaw angle,pitch angle and roll angle errors),which will directly affect the machining accuracy of the machine tool.The traditional guide rail motion error detection method usually can only detect one kind of error,and the efficiency is low.Therefore,a five-degree-of-freedom motion error optical measurement system is proposed in this paper,which has the advantages of simple optical path,low cost,high measurement accuracy and short measurement time.Firstly,this paper introduces the method of measuring the multi degree of freedom motion error of the guide rail,and analyzes the factors that affect the accuracy of each motion error measurement;Then,according to the measurement method,the light path structure and the overall structure of the system are designed and built,which effectively reduces the cost of the instrument,improves the degree of integration,and makes the instrument easier to be used for machine tool guide rail measurement;At the same time,the measurement software is designed and written to realize the functions of data acquisition,filter processing,error compensation,data display and storage.Sensitivity calibration experiments,stability experiments,repeatability experiments and precision comparison experiments were carried out on the instrument.The experimental results show that within 30 minutes,the error stability of the straightness and angle errors of the measurement system are within 0.7 μm and 1″;The comparison residuals of pitch angle,yaw angle and pitch angle,roll angle errors are within ±0.9 ″ and ±1.5 ″.At the same time,the measurement system also solves the problem that the measurement accuracy is greatly affected by the parallelism error when using two parallel beams to measure the rolling angle error.The experiment shows that when there is a parallelism error of 15.4 " between the two beams,the comparison residual of the rolling angle can be reduced from 44 " to-2.7 ".Finally,an error model that conforms to the Abbe-Bryan principle is also established for the two-dimensional linear motion platform.The motion error of the platform guide rail is measured by the measuring system,and then the diagonal positioning error is calculated according to the error model.The diagonal positioning error obtained by the instrument is compared,and the comparison residual is within ±4 μm.