Determination method and application of instantaneous rotation center of CNC machine tool XY worktable

The XY worktable is a critical component of CNC machine tools and a significant source of measurement errors in on-machine measurement systems. To accurately compensate for these errors, this study proposes a compensation method based on the instantaneous rotation center of the worktable. First, the definition of the yaw, pitch, and roll instantaneous rotation centers of the machine tool XY worktable is proposed, and the determination model of the instantaneous rotation center is established. A simplified model of the XY worktable is established by using three-dimensional software. The existence of the yaw instantaneous center, pitch instantaneous center, and roll instantaneous center is verified by automatic dynamic analysis of the mechanical system’s dynamic simulation analysis method. The coordinate positions of each instantaneous center during the movement of the worktable along the X and Y directions are plotted. At the same time, the three-axis velocity sensors are used to build the experimental device for the actual experiment. According to the measured three-dimensional velocity data and the established instantaneous rotation center determination model, the actual location of the instantaneous rotation center is calculated, and the correctness of the established determination model is verified. On this basis, the influence of the yaw instantaneous center, pitch instantaneous center, and roll instantaneous center on the positioning error of the X and Y guide systems of the worktable is analyzed, and the positioning compensation model of the guide systems by using the instantaneous center is established. Meanwhile, the experimental devices for measuring the positioning error, yaw angle motion error, and pitch angle motion error of the worktable guide systems are established using a laser interferometer. The traditional positioning error compensation model and the above-mentioned positioning error compensation model of guide systems using the instantaneous center are used to compensate. From the compensation results, the positioning error compensation model based on the instantaneous center of the guide systems is better, and it can improve the measurement accuracy of the CNC machine tool on-machine measurement system more effectively.