05861366

j

05861366 Yang, Xujing Chen, Zezhong C. A practicable approach to $G^{1}$ biarc approximations for making accurate, smooth and non-gouged profile features in CNC contouring. Comput.-Aided Des. 38, No. 11, 1205-1213 (2006). 2006 Elsevier Science, Oxford EN $G^{1}$ biarc approximation gouging prevention CNC contouring high precision machining dies/mold machining

doi:10.1016/j.cad.2006.07.006

Summary: Extensive research on $G^{1}$ biarc approximations to free-form curves has been conducted for the production of accurate, smooth and non-gouged profile features in CNC contouring. However, all the published work has only focused on improving the fitting accuracy between the biarc curve and the nominal free-form curve of a profile and minimizing the biarc number; as a result, the radii of the concave arcs of some biarcs could be less than the pre-determined tool radius, and the tool would overcut these arcs in machining, eventually gouging the profile. In this work, a new, practicable approach is proposed to completely solve this problem. The main feature of this approach is to find the gouging-free parameter interval of a biarc family, among which the radii of all the concave arcs are larger than the tool radius, and then to search in this interval for a best fitting biarc so that its approximation accuracy is within the tolerance. This approach is robust and easy to implement and can substantially promote the use of $G^{1}$ biarc curves for CNC machining.