Two-dimensional thermal error compensation modeling for worktable of CNC machine tools

The conventional thermal error compensation for computer numerical control machine tools in ISO 230-3:2007 is based on a single positioned point on a worktable; this guideline ignores the thermal error differences of different locations across an entire worktable. As a result, a reduced compensation effect is achieved for the whole worktable, although the single-point compensation model generally provides high prediction accuracy. The 2D thermal error compensation method, which can greatly improve the compensation effect of the worktable, is proposed in this study. This method builds a 2D thermal error map model parallel to the worktable at each time point. The thermal error at any position on the workbench can be predicted accurately. Thus, this compensation method can significantly reduce the influence of thermal error differences on the compensation effect across the whole worktable. The thermal error prediction results and compensated experimental results show that the compensation effect of this new method is better than that of the conventional single-point method for the whole worktable.