Kinematic Calibration of a Hybrid Machine Tool with Constrained Least Square Method

Kinematic calibration is an effective way to improve the kinematic accuracy of hybrid machine tools. Conventional calibration methods require position and attitude measurements for each measurement pose, and the measurement process, especially the attitude measurement, is extremely complicated. In this paper, a calibration method that only requires position measurement and alignment is proposed. Measurement process can be done using only three dial indicators. Based on this measurement method, a constrained least squares identification method based on the regularization solution is proposed to solve the ill-posed problem. The proposed calibration method is verified by simulation and experiment. The proposed method can complete the calibration with a small measurement cost, which greatly improves the calibration efficiency.