Efficient Toolpath Generation Method for High-Quality and High-Accuracy Machining of Curved Surfaces

Currently, there is no function in commercial CAM systems to generate optimal quality machining for curved surfaces. In computer-aided manufacturing (CAM) systems, the toolpath (cutter location data) is derived as an approximately straight-line segment based on a plane approximation surface instead of a free-form surface from the designed shape. Due to this approximation, machining accuracy and quality are decreased, especially in the region with characteristic lines like in an outer automobile covering part. This paper presents an algorithm procedure for toolpath generation to process complex parts with characteristic curves with high-quality and high-accuracy machining by dividing the surface into different regions, the region where machining accuracy is not required as a plane approximation surface and the remaining region where accuracy is required as free-form surfaces. The proposed method was confirmed by machining experiments that actual machining realized high machining quality and accuracy compared to the conventional CAM system.