适用于自由曲面高速高精加工的旋转轴位置优化算法

Algorithm of Optimization of Rotation Axes in Free-form Surface Machining

针对自由曲面加工中机床旋转轴角度变化过大导致刀具姿态误差较大和旋转轴频繁加减速问题,在分析刀具姿态误差与旋转轴转动幅度间关系的基础上,提出一种适用于自由曲面高速高精加工的旋转轴位置优化算法。在根据旋转轴转动幅度条件确定初始修正区域后,采用递归扩充原则确定待修正区域,并在保证工件坐标系下刀具切触点坐标不变的情况下,采用等幅旋转法则对各待修正区域的旋转轴坐标值进行优化。仿真和实际加工结果表明,本算法能够对加工中旋转轴角度进行修正,避免大幅旋转轴转动,减少加工中的刀具姿态误差,在提高加工精度的同时缩短了加工时间。

Currently existing tool path planning algorithms may result in large variations of tool rotation axes in five-axis machining of free-form surfaces, leading to problems of non-linear errors and acceleration and deceleration of rotation axes. Aiming at solving these problems, an algorithm of optimization of rotation axes is proposed after analyzing the relationship between values of rotation angles and non-linear errors. Values of rotation angles can therefore be taken as the criteria for determination of areas that should be optimized and the corresponding regions are defined by regional recursive extended principle. While the positions of tool tips are still maintained, rotation axes are changed according to the principle of equal rotating amount. Results show that the algorithm has advantages of less machining errors, shorter machining time, and higher machining efficiency.