【摘要】 阐明了用有理参数形式表示圆弧的充要条件。在此基础上建立了由三点确定的双圆弧的有理参数方程。提出了有理双圆弧插值的算法，其中包括建立连续性方程，计算弦切角以及构造样条曲线。此外，构造了一类以双圆弧样条为横向截线的直纹曲面更多还原

【Abstract】 The necessary and sufficient conditions for representing circular arc by rational parameter form are explained. On the base, the rational parameter equation of the bicircular arc determined by three points is established. The interpolation of rational bicircular arcs is provided, that contains the establishing equation of continuity, calculating the angles between chords and cutting lines, and constructing the spline curves. Besides a class of surfaces with line segments are constructed and it’s cross setions are bicircular arc splines.更多还原