基于自由曲面有向Voronoi区域划分算法的机器人加工刀轴低摆振路径规划

Low vibration tool path planning of machining robot based on free-form surface with directed Voronoi tessellation

针对自由曲面刀具路径规划中,刀轴摆动带来的振动影响加工质量的问题,提出有向Voronoi区域划分算法。基于该算法实现了刀轴运动优化的复杂自由曲面的区域划分,并光顺连接区域之间和区域内部的刀具路径,得到曲面整体实际可加工的刀具路径。应用该算法与UG不同路径规划的刀轴矢量变化进行了对比实验,结果显示刀轴矢量变化均值和累计值减少了30%,方差降低了近60,从而验证了该方法的刀轴矢量变化明显小于传统的对整个加工曲面的路径规划,可减小加工过程中的机械振动和冲击,保证加工刀轴姿态的稳定性,从而提高加工精度,减小对加工设备寿命的影响。利用工业机器人完成铣削实验,进一步验证了该方法的可行性和有效性。

To solve the problem of frequent large swing of tool axis in path planning of free-form surfaces, a Directed Voronoi Tessellation method (DVT) was proposed for dividing the surface. By connecting the outside and the inside of divided surface, the whole tool path which could really be machined was got. Compared with the control of UG with different path planning, the mean and cumulative variation of axis vector decreased around 30% and the variance was reduced by nearly 60%, which had verified the change of the tool axis vector of the proposed method was less than that of the traditional machining surface, and could reduce the mechanical vibration and impact in the process. Thus the stability of the shaft attitude was conducive to improving the processing accuracy and reduce the impact on the life of the processing equipment. The milling experiment was completed with the industrial robots, and the results further confirmed the feasibility and effectiveness of the method.