Tool paths generation strategy for polishing of freeform surface with physically uniform coverage

The tool path used for polishing applications with characteristic of physically uniform coverage, which is similar to the iso-scallop path in milling operations, is significantly important to facilitate uniform material removal and acquire low surface roughness and consistent surface quality. In this paper, tool path planning method for physically uniform coverage instead of traditional geometrically uniform coverage of polishing path based on scanning mode is further investigated and an efficient iterative approximation algorithm is proposed. Then a complete spiral path generation strategy for small tool polishing of freeform surface is presented, which uses a cyclic iteration correction and driving method to produce spiral path with physically uniform coverage. At the same time, this strategy uses surface expansion and re-parameterization techniques to avoid edge effect in polishing. The effectiveness and robustness of the developed polishing path generation technique are proved by case studies. And the superiority of the planned polishing path over the traditional path in promoting uniformity of material removal is examined through the practical application of polishing.