Research On The Rotational Error Measurement Of Spindle Based On Dynamic Interferometer

The spindle of machine tool is the basic structure unit of the machine tool, the spindle rotational error direct response the pros and cons of dynamic performance of machine. Accurate and effective test of the machine spindle rotational error is the important link of research on dynamic characteristics of machine tool and improve the machining accuracy of machine tool. Therefore, the establishment of spindle error test system with high accuracy and high reliability and based on the system to carry out the test and analysis of the spindle rotational error motion has important engineering application value and practical significance.Firstly, based on systematic analysis the test method and principle of existing spindle error, this paper proposes a new method of spindle rotational error detection base on dynamic interferometer. By comparing the working principle of the static interferometer and dynamic interferometer, demonstrates the dynamic interferometer as high-precision detection device to realize the possibility of spindle rotational error real-time test. Then, use high precision optical parallel as standard test pieces, set up based on dynamic interferometer with high precision servo motor spindle rotary error test experiment device. Through analyzing the characteristic of the optical flat surface morphology change can be concluded the error of spindle.Secondly, after analysis the main factors influencing the precision of optical parallel surface shape and the measure to restrain the deformation, i design a special clamping and adjusting device of optical parallel to test the spindle rotational error. Based on finite element analysis, detailed analysis the deformation of optical parallel surface with different clamping way, present reasonable way of clamping, Implement nanoscale precision clamping requirements.Thirdly, to test optical parallel surface which installed in servo motor spindle end by dynamic interferometer, get aberration image from laser beam interference. To correct the original aberration figure, get more precise aberration figure. Adopt the image processing technology method of the median filtering, gray threshold segmentation method, corrosion expansion processing to obtain edge features image of optical parallel surface feature circle, use the method of minimum circumscribed rectangle get features round centroid coordinates, comprehensive analysis the aberration figure processing results of different angles of spindle interferometer, to calculate the spindle rotation error.In the end, on the basis of systematic analysis the principle of dynamic test interferometer spindle error and establishment of spindle error test experimental system, carry on a preliminary experimental test spindle rotational error.Experimental results show the design of optical parallel special fixture has the feature of high precision micro adjustment, convenient operation and realize the optical parallel surface installation angle within 2 microns. The new test method proposed which can realize micron grade spindle rotation error test, and verify the validity of this test method.