Abstract: To increase the NC machining efficiency of the complex triangular mesh model, a new method of tool combination optimization is developed on the premise of demanded accuracy. Aiming at minimum tool-path length, the effects of the model differential geometry information on the machining efficiency and accuracy are taken into account. Firstly, the model is segmented into several feature sub-regions, and different tool path planning methods are adopted for different feature sub-regions. Then the more precise tool-path length estimation model is established. After selecting suitable standard tool combinations and estimating their path lengths, the cubic B-spline curve is fitted, and the minimum value is obtained by calculating the first derivative vector of the curve. Finally, the standard tool corresponded to the minimum value is selected as the optimal tool. The proposed method is programmed in the VC++ environment and is experimented, and the experimental results demonstrate the feasibility and validity of the method.

Key words: triangular mesh, tool combination, estimated tool-path length, region segmentation, interference detection

摘要： 在满足复杂三角网格模型数控加工的精度要求下，为提高加工效率，提出了刀具组合优化方法。该方法以刀具轨迹长度最短为目标，并综合考虑模型微分几何信息对加工效率和精度的影响。首先根据面片法矢和曲率将模型分割为多个特征子区域，不同类型的特征子区域采用不同的刀具轨迹生成策略；建立各类型子区域的精确轨迹长度估算模型；选取合适的标准刀具组合并估算轨迹长度，拟合三次B样条曲线，求取曲线一阶导矢得到最小值，选择对应的标准刀具尺寸作为最优刀具尺寸。算法在VC++环境下进行了编程实现和算例验证，结果表明该方法是可行有效的。

关键词: 三角网格, 刀具组合, 刀轨长度估算, 区域分割, 干涉查找