Effect analysis of dynamic characteristics of a parallel machine tool on machining accuracy
XU Zhao-tang1, 2, LIU Yuan-wei1, WANG Tong-yue1, WU Hai-bing1
1. Key Laboratory of Digital Manufacturing Technology, Huaiyin Institute of Technology, Huaian, Jiangsu, 223003；2. Department of Traffic Engineering, Huaiyin Institute of Technology, Huaian, Jiangsu, 223003
Abstract：In order to improve machining accuracy of a parallel machine tool, effect of dynamic characteristics of a parallel machine tool on machining accuracy is analysed. Dynamic equation of a parallel machine tool can be obtained by Newton-Euler approach. Drive force of a leg is solved from the dynamic equation. According to relation between axial extension length and drive force of a leg, length error of a leg is calculated. With a leg length of length error-free used as optimization objective, position and pose of a moving platform are got by optimization method. Position error and pose error of a moving platform is obtained by a comparison between the position and pose with length error of a leg and the one without length error of a leg. According to position of a tool in a coordinate system of a moving platform, error of machining position is calculated, effect on accuracy of machined parts is obtained. The result shows that error of machining position of a tool is caused by length error of a leg in a parallel machine tool, which produces form and position and dimension error in a machined part. Disturbed error of machining position of a tool is caused by disturbance of length error of a leg from rotor eccentricity of a parallel machine tool, which effects surface roughness of a machined part.
2013, Vol. 32 
