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Real-Time Tool-Path Generation for 3-Axis CNC Machining of NURBS Surfaces

NURBS 곡면의 3축 CNC 가공을 위한 실시간 공구경로 생성

  • 구태훈 (단국대학교 대학원 기계공학과) ;
  • 지성철 (단국대학교 기계공학과)
  • Published : 2003.08.01

Abstract

In CAD systems, a surface to be machined is expressed by a series of curves, such as B-spline, Bezier and NURBS curves, which compose the surface and then in CAM systems the curves are divided into a large number of line or arc segments. These divided movement commands, however, cause many problems including their excessive size of NC data that makes almost impossible local adjustment or modification of the surface. To cope with those problems, the necessity of real-time curve or surface interpolators was embossed. This paper presents an efficient real-time tool-path generation method fur interpolation of NURBS surfaces in CNC machining. The proposed tool-path generation method is based on an improved iso-scallop strategy and can provide better precision than the existing methods. The proposed method is designed such that tool-path planning is easily managed in real-time. It proposed a new algorithm for regulation of a scallop height, which can efficiently generate tool-paths and can save machining time compared with the existing method. Through computer simulations, the performance of the proposed method is analyzed and compared with the existing method in terms of federate, total machining time and a degree of constraint on the scallop height.

Keywords

Tool-Path Planning;Iso-Scallop Method;CNC;Surface Machining;NURBS;Interpolator

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