高精度なオフセット面の生成手法

抄録

Sculptured surface on large-scale dies with complex curved surface such as automobile body parts is usually fabricated by ball-end-mill using 3-axis NC milling machines. Normally, toolpath for machining products is generated by geometric calculation between product model and tool. However, if the product has a large and complex surface, number of polyhedrons approximating the product increases, so a calculation time becomes enormous. In past research, methods of geometric calculation using offset surface generation and the parallel processing function of GPU were proposed to solve this problem. However, these methods didn't consider error due to the approximation process and increase in memory usage. To reduce this geometric error and memory usage, we propose a new method for accurate offset surface generation. In this method, the offset surface is generated by vertices of the polyhedron constituting the product and the tool radius. This approach enables accurately calculating a height of the offset surface of the area approximated by the fine polygon shape while suppressing an increase in memory usage.