由控制多边形构造的圆弧样条曲线

为CAD系统提出了一种由控制多边形构造的圆弧样条曲线。首先分别为C-型和S-型双圆弧各找到了一种比传统方式更优的缺省约束方式,简化了程序生成曲线的运算过程,并给出了生成算法。然后通过分析曲线的动态生成性能,对新控制顶点的落点区域进行了精确划分,并给出了对应的曲线生成形式,确保了曲线生成的动态连续性。最后还对曲线的局部支撑性、连续性、构造曲面等扩展性能做了一定的探讨,验证了将其应用于CAD系统的可行性。它的应用将为数控加工领域带来许多方便。图11参9

Arc Spline Constructed by the Control Polygon

A new kind of arc spline constructed by the control polygon is proposed for CAD system.Firstly,a better default constrained way was found for both C-type and S-type biarcs.The algorithm process was simplified and proposed and get the producing algorithm.Then,divided areas for the new control vertex position through the analysis of the dynamic generate property of this arc spline.The corresponding generate forms of different areas were presented to ensure the dynamic continuity of the curve.In order to make sure it is feasible to be used in CAD system,some extend properties of this arc spline,such as local support,continuity,build curve surface,etc.,were discussed at the end of this paper.The use of this arc spline in CAD system will make a lot of convenient for the CNC field.Ch,11 fig.9 ref.]