HSM toolpath generation with capsule-based region subdivision

Abstract

High-speed machining (HSM) has become a research hotspot in the manufacturing field these years. In HSM, it requires the toolpath to be very smooth. Any sharp corners will cause decelerations of the feed axes. However, corners are inevitable in the toolpath generation process. This work focuses on smooth toolpath generation for HSM pocketing. The concept of region subdivision is proposed and implemented. With this concept, the input pocket is firstly subdivided into two classes of sub regions: the HSM regions and the low-speed machining (LSM) regions. For the HSM regions, very smooth path curves are filled and high machining speed is set. For the LSM regions, sharp corners are allowed and low machining speed is set. In this work, the HSM regions are extracted as capsule-shape regions inside the pocket. For these capsules, paperclip-shape curves are used as the HSM toolpath. These curves are smoothly connected by semicircles and line segments. The path intervals are strictly controlled so that constant radial cutting depth can be achieved. For the rest regions inside the pocket, conventional offset curves are filled as the LSM toolpaths. The proposed capsule-based HSM toolpath generation method is tested with several comparative examples. Results show that the proposed method could generate larger HSM regions and more efficient toolpaths than the maximum inscribed circle-based method from the authors’ previous work.