基于偏置点寻优的弧面凸轮侧铣加工刀轨算法

Side milling cutter path algorithm of globoidal cam machining based on optimization of bias point

针对弧面凸轮的非等径侧铣加工存在法矢异向误差的问题,为寻求加工误差最小的刀具位置,分析了理论非等径刀轴曲线的性质,根据等距曲面的误差传递关系,结合偏置点寻优算法进行刀位优化,提出了一种以非等径刀轨曲面与拟合直纹面误差最小为目标的双向搜索刀轴优化算法.在此基础上,通过遗传算法得到较高精度的优化数值解,并将解算出的刀轴端点作为初始数据,利用NURBS(非均匀有理B样条)插值反算重构侧铣加工刀轨直纹面.数值计算和仿真结果验证了该算法的有效性.

Machining error caused by different directions of normal vector along the contact were una- voidable when using the cutter with the smaller diameter. Based on the analysis of geometric proper- ties of the curve of theoretical tool axis generated by the above method and the transitive relations of deviation between equidistant surfaces, a method was proposed to reduce the errors between the theo- retical tool axis trajectory surface and reconstructed NURBS （non-uniform rational B-spline） ruled surface by bidirectional searching on the theoretical tool axis surface. The theory of the points offset algorithm was applied to build the optimization model and it was resolved by the genetic algorithm. The result was used to reconstruct the NURBS ruled surface. Numerical calculation and simulation examples were described to verify the effectiveness of the algorithm proposed.