Parallel Contour Path Planning for Complicated Cavity Part Fabrication using Voronoi-based Distance Map

To generate parallel contour path for direct production of complicated cavity component, a novel path planning based on Voronoi-based distance map is presented in this paper. Firstly, the grid representation of polygonal slice is produced by hierarchical rasterization using graphics hardware acceleration and divided into Voronoi cells of contour by an exact EDT (Euclidean distance transformation). Then, each VCI (Voronoi cell of inner contour) is further subdivided into CLRI (closed loop region of inner contour) and OLRI (open loop region of inner contour). Closed paths for each CLRI and the block merging VCO (Voronoi cell of outer contour) and all OLRIs are generated by local and global isoline extraction, respectively. The final path ordered in circumferential and radial directions is obtained by sorting and connecting all individual paths. In comparison with conventional methods such as pair-wise intersection and Voronoi diagram, the proposed algorithm is numerically robust, can avoid null path and self-intersection because of the application of distance map and discrete Voronoi diagram. It is especially used for FGM (Functionally Graded Material) design and fabrication.