Fast Computation of Collision-Free Cutter Postures Using Discrete Representation of Workpiece Shape

Abstract In the manufacturing of complex-shaped parts, particularly using simultaneous 5-axis machining technology, as machining progresses, excess material is removed, and the workpiece shape becomes smaller. Therefore, the holder and workpiece are less likely to collide, and the range of possible tool postures increases. However, in the quest for automation, incorporating such a tool posture “margin” into calculating machining commands has not yet been possible. The final goal of this research is to realize a software system that can automatically generate commands for the 5-axis machining considering the shape change of the workpiece. The workpiece shape in the machining process can be computed using a geometric machining simulation. In the simulation, discrete methods, such as voxel or dexel models, are commonly used to represent the workpiece shape. This study developed a fast method to calculate a safe tool posture for such a discrete workpiece model without holder collisions. Our method uses the parallel processing function of the graphics processing unit to accelerate the computation. The software was successfully developed and its effectiveness was verified through several computational experiments.