Research on positioning error compensation for micro milling machine tool

Micro milling has many advantages in fabricating three-dimensional (3D) structure in micrometer scale. The micro milling machine tool with high positioning accuracy is of great importance for getting micro structure with high profile precision and good surface quality. Meanwhile, the method of position error compensation is a good way to improve the accuracy of the micro milling machine tools. In this paper, a software method is adopted to compensate the positioning error and improve the positioning accuracy. According to error cancellation theory, the compensation values are generated and compensation tables are built to adjust the positioning error in the NC system based on Industrial Motion and Automation Control (IMAC). The positioning accuracy of linear motor is ±0.3 μm without backlash after compensation. In order to verify the effectiveness of compensation on the machining performance, concave spherical surfaces are processed on the micro milling machine tool. The experimental results show that the profile radius error of the spherical surface machined with compensation decreases more than 60%.