Analysis and modeling of dynamic positioning error of CNC machine tool XY worktable

In order to compensate the measurement errors of the on-machine measurement system caused by the XY worktable error accurately under the influence of multiple factors, the structural characteristics of the XY worktable are analyzed in detail. The dynamic positioning error model of the XY worktable motion components such as the grating measurement systems, the ball screw assemblies, the guide rail system manufacturing errors and the friction forces under the influence of the above factors are established, and the theoretical model of the dynamic positioning error of the XY worktable is derived. It can be seen from the analysis process that the main factors affecting the dynamic positioning error are the movement speed of the worktable, the weight of the workpiece to be measured, the installation position of the workpiece and the friction force. The actual model parameters are substituted into the theoretical model to calculate the dynamic positioning error of the worktable under different influencing factors by using the technical indicators of the experimental platform. From the analysis of calculation results, it can be seen that the dynamic positioning error is the smallest when the moving speed of the worktable is 12 mm/s, and this velocity is defined as the best measuring speed，which lays a good theoretical foundation for improving the dynamic machining accuracy of machine tools and the measurement accuracy of on-line measurement system.