Approximate tool posture collision-free area generation for five-axis CNC finishing process using admissible area interpolation

摘要

This paper proposes an efficient algorithm to generate tool posture collision-free area for the whole free-form surface during five-axis CNC finishing period. The algorithm is consisted of two phases: sampling and interpolation. In the first phase, a few points are picked on the surface and the admissible area of tool posture is calculated at each point. The admissible area is a two-dimensional figure on the plane. Base on the assumption that the admissible area of adjacent surface points should transform continuously, so in the second phase, the admissible area of the sampling points are interpolated with cubic B-surface interpolation technique, forming an expression as Q(u, v), through which when the parameters u and v are assigned, the global collision-free area for the corresponding surface point can be easily calculated. The proposed algorithm is efficient because only a few surface points are needed to get the expression. The proposed algorithm is programmed and tested. Results show that the algorithm is relatively precise and efficient while considering the whole surface.