Unified error model based spatial error compensation for four types of CNC machining center: Part II—unified model based spatial error compensation

•The spatial error which is relative to each axis is non-linear and there is no regularity.•An orthogonal polynomials-based automatic error modeling application was designed.•A multi-thread parallel processing based error compensation controller was designed.

In this paper, a spatial error compensation method was proposed for CNC machining center based on the unified error model. The spatial error distribution was analyzed in this research. The result shows that the spatial error is relative to each axis of a CNC machine tool. Moreover, the spatial error distribution is non-linear and there is no regularity. In order to improve the modeling accuracy and efficiency, an automatic error modeling application was designed based on the orthogonal polynomials. To realize the spatial error compensation, a multi-thread parallel processing mode based error compensation controller was designed. Using the spatial error compensation method, the machine tools' accuracy is greatly improved compared to that with no compensation.