基于Zmap网格三轴加工无干涉刀具轨迹的加速算法

介绍和扩大了数控加工中的刀位面和保护面的概念,研究和实现了一种基于曲面离散生成三轴加工无干涉刀具轨迹的算法。通过Zmap网格节点的竖直线与三角片的刀位面和保护面求交并取z值最大的交点即为无干涉刀位点,采用双节点插值方法解决了生成刀具轨迹时因参考走刀步长不合适而产生的运动过切问题。该算法完全采用几何求交运算,过程简洁且精确度高,但需处理的数据点较多、运算量大,为此提出了几种生成轨迹的加速方法。

An Algorithm of Interference-Free Tool Path Based on Zmap Model

An algorithm of 3-axis interference-free tool path is researched and realized by cutter location surface and protection surface of discrete triangular facets of machined surface. Par surface under machining is first subdivided into triangular facets and the corresponding Zmap showing the projection of each step of cutter movement is constructed. Interference-free cutter location point (CLP) is found by intersecting vertical lines originating from each cross point of Zmap with the cutter location surface and protection surface of relevant triangular facets. CLP is the one with maximum Z-coordinate. This algorithm is simple but high precision because it only makes use of geometry intersecting computation. Some measures are taken to avoid duplicated computation of facets and cutter collision within each step of movement.