A compensation method for the geometric errors of five-axis machine tools based on the topology relation between axes

This paper proposed a new compensation method of geometric errors for five-axis machine tools. First, the principle of time-consuming traditional compensation method based on iteration of forward and inverse kinematic solution is analyzed. According to the analysis, the essential cause of this iteration is considered as the synchronous solving of compensated numerical control (NC) code of each axis. This iteration process can be avoided by the algorithm proposed in this paper. This new algorithm compensates NC code in a new order based on the topology relation between each axis in kinematic chain of machine tools. Based on this new order, the universal compensation process for three typical configurations of five-axis machine tools is also established. This new compensation method not only decouples the compensation process between linear and rotary axes as traditional method does, but also decouples the compensation process among each rotary axis and linear axis. Therefore, different with traditional method, there is no need to use time-consuming iteration process to calculate compensated position command of each axis. Also, it contains no complex computation such as derivation or evaluation of high order pseudo-inverse matrix which exist in traditional methods. Therefore, the compensation efficiency is significantly improved. Finally, the accuracy and efficiency of this new method is simulated and verified experimentally on a five-axis machine tool.