A NEW APPROACH TO DETERMINING OPTIMUM TOOL SIZE FOR FINISH MILLING OF NURBS PROFILES

摘要

A curve model of non-uniform rational B-spline (NURBS) has been widely adopted in mainstream CAD/CAM software systems to design complicated geometries of mechanical parts, for example, the curved profiles of pockets, sides, and islands. To accurately produce these geometries in finish milling, the size of the cutting tool should be optimized in order to attain high machining efficiency. Although this has been a research focus for a decade, optimal tool size determination still remains as a technical challenge. This work proposes a new approach to addressing this challenge so that the cutting tool of the largest allowable size is selected for finish machining without global and local gouge on the part. In this approach, a global optimization problem is formulated for the optimum tool size, and particle swarm optimization (PSO) method is employed to solve this problem. As a result, this approach can efficiently optimize the tool size for finish machining of the NURBS profiles; on the other hand, it can be more accurately and efficiently to detect global and local gouge on the profiles. Since it is easy to implement, this approach can be directly used in the manufacturing industry.