Research On The Measurement And Identification Method Of The Geometric Error For VMC650m Five-Axis CNC Machine Tool

The machining precision is one of the most important performance indexes for machine tool. With the extensive application of the high-precision parts, the requirements for the machining accuracy are increasing day by day. However, the further improvement of the five-axis CNC machine tool's accuracy is restricted by thermal deformation, vibration, friction, inertia and other factors from which manufacturing, assembly, control and movement. Therefore, the current study focuses on how to reduce the errors of five-axis CNC machining and improve its accuracy.This paper takes VMC650m five-axis high speed machining center of table-tilting as the studying object, to research the geometric error modeling, error measurement and identification the five-axis CNC machine tool and the processing verification of the cone. The following are the key contents:(1)Based on multi-body system theories, this paper uses the characteristic matrixes to describe the relative position and gestures between any two body in MBS. After that, the paper established the geometric error modeling for VMC650m five -axis CNC machine tool.(2)The geometric error measurement and parameter identification of translational axis and rotation axis for VMC650m five -axis CNC machine tool are researched. The measurement of translational axis was done by the laser interferometer. The positioning errors of twelve test lines are measured and all of 21 geometric error parameters for translational axis can be identified according to the twelve-line method. The measurement of rotation axis was done by the ball-bar. Using it to measure the displacement error of the 3 locations at the X, Y, Z three directions, when the rotation axis have rotated different angles, and finally to get the 6 geometric error parameters of rotation axis at any angle, according to identification method.(3) The measurement on the VMC650m machine tool was based on researching geometric error measurement and identification method, including the twelve-line measurement experiment in translational axis and the ball-bar measurement experiment in rotation axis. After data processing, all the geometric error parameters of five-axis CNC machine tool can be obtained.(4)This paper carried out the experiment verification based on the theoretical research of VMC650m five-axis CNC machine tool. And to use the pre and post error compensation to process the cone at the same location of machine tool respectively. Then using the five-coordinate measuring machine to measure and compare the contour error of the two cones. This paper proposes the geometric error measurement method of five -axis CNC machine tool's rotation axis.According to the experiment, the method is proved to be correct..It is very important for five -axis CNC machine tool to improve its processing performance.