Please use this identifier to cite or link to this item: `http://hdl.handle.net/11455/2007`
 標題: 圓弧嵌合B-Spline曲線產生不干涉之近似曲線Interference-free Curve Fitting with Arcs for B-Spline Curves 作者: 高家榮Kao, C.Z. 關鍵字: 刀具路徑產生;干涉;雙圓弧嵌合法;單圓弧嵌合法;B-Spline曲線;G1連續;B-Spline curve;G1 continuity;tool path generation;interference;Biarcs fitting;Circular single-arc fitting 出版社: 機械工程學系 摘要: 本論文的研究目的，是對於B-Spline曲線提出一個有效且快速的近似方法 ．此方法產生的近似曲線，不僅能不干涉原曲線，而且具有G1連續的特性 ．本文所提的方法，是先利用節點插入演繹法，將B-Spline曲線方解成片 段的Bezier曲線，再利用Bezier曲線，再利用Bezier曲線的凸殼特性，以 凸殼上的部份直線段邊界來近似Bezier曲線，進而使產生的近似直線段全 部位於曲線的同一側；再合併各別Bezier曲線的近似直線段，即是不干涉 到原B-Spline曲線的近似直線段；再將此近似直線段，以雙圓弧嵌合法與 單圓弧嵌合法，來產生一條由圓弧與直線段所構成的圓滑曲線，如此曲線 不僅能不干涉原曲線，而且還會具有G1連續的特性；若將其用於數控切削 的路徑產生上，則可完全消除一般近似法之過切問題，且模穴邊界表面稜 紋的問題便能加以改善．The object of this paper is to develop a efficinet algorithm to approximatea B-Spline curve. The algorithm is applied to construct a smooth curve withG1 continuity and without causing any interference.A B-Spline curve is decomposed into piecewise Bezier curves. Using convexhulls of the Bezier curves to protect the original curve from interferencethe line segments on the same side consist the approximating curve. Basedon the obtained approximating line segments, Biarcs fitting and Circularsingle- arc fitting methods are applied to construct a smooth curve with G1continuity and without causing any interference. If the resulting curve isapplied to generate tool paths for pocketing boundaries with B-Splinecurve, the overcutting problem can be eliminated completely and abruptdirection changes on tool paths can be greatly improved. URI: http://hdl.handle.net/11455/2007 Appears in Collections: 機械工程學系所