Generation of offset curve for pocket with islands based on offsetloop dissection method

Abstract

In pocket machining, an optimal offset curve generation has been a very difficult problem. In this study, we focus our attention on the dissection of intersecting offset loop. Then, we introduced offset loop entity (OLE) as a key concept. The conspicuous feature of OLE is the capability of enabling every offset curve to be generated without taking account of interfering/intersecting relationship with the pocket/island boundary curve after the first offsetting had performed. Moreover, the devised virtual OLE allows us to treat every kind of island offset loop as same as the pocket offset loop at once. Eventually, the offsetloop dissection method (ODM) is developed. To verify prominent features of ODM algorithm, such as simplicity, applicability, and even consistency, prototype systems are implemented and then examined with actual pocket machining. The results show that the use of OLE concept for offset curve generation is a reliable and proper approach, and ODM algorithm fulfils the requirements for pocketing.