Research On Measurement System Of Ultra Precision Lathe Spindle Rotation Error

The rotation error of ultra precision spindle is the main factor to surface quality of machined workpiece. Furthermore, it is very important to study the accuracy of rotation error of ultra precision spindle, evaluate the ro tary precision of the spindle, predict surface shape error of workpiece,compensate machining error and improve processing accuracy.The spindle rotation error contains spindle radial motion error, tilt error and axial error. In the test, the measurement data is mixed with shape error which can’t be negligibled. Therefore, the core problem of extracting the rotation error of the spindle is error separation.In this paper, based on the three point method in frequency domain technique, the radial motion error of the spindle is separated and the tilt error mathematical model is setted up and separate the tilt error from the data of double cross sectiones. Establish the actual model of the sensor’s measurement values and prove that eccentric motion of least squares can’t be separated from the spindle radial motion in the aspect of the analytical composing. A quantitative analysis is given about the influence of in stallation angle deviation and coordinate system location to the accuracy of the error separation to offer the theory assurance of nanometer order accuracy of the measurement data of spindle rotation error of the ultra precision lathe. Analyse the basis of removing the first order harmonic component in terms of the workpiece surface forming. Signal denoising, filtering, extraction of synchronous motion error and the three point method of error separation are done continuously in the frequency domain. Establish the tilt error separation algorithm of the spindle, and separate the tilt motion error from the measurement datas.Design the experiment scheme of measuring radial motion error and tilt motion error and build test system for the spindle rotation error of the ultra precision lathe. Three point method error separation is carried out to obtain the radial motion error of the spindle. On the basis of the radial error separation, the tilt motion error is carried to abtain the tilt motion error using the tilt error seperation algorithm established in this paper. The variation of the radial motion error and the tilt motion error at different revolution is analyzed. Evaluate the rotaty accuracy of the spindle using least square method and analys the influence of spindle rotation error on machining workpiece surface. The upper computer software is designed for the test system of the spindle rotation error of the ultra precision lathe, which contains data acquisition, data processing, error separatio n and evaluation.The research results of this paper is to establish a spindle rotation error testing system, including the hardware and software. Quantitative analysis of the reliability of the hardware of the test system to ensure the reliability of the measurement data. The tilt error seperation algorithm and the actual measurement scheme are established. The radial motion error of the different section can be calculated by the tilt error.