中文摘要：

曲线和曲线求交计算是CAGD领域的一个基本问题，但现有的求交算法都无法处理曲线重合的情况．在2条三次Bezier曲线重合判断条件的基础上，提出一种判断2条三次B样条曲线是否重合的算法．对于每条B样条曲线，首先将其分割成若干Bezier曲线段，然后判断2条Bezier曲线段是否可以合并为一段；通过合并Bezier曲线段，将2条三次B样条曲线的重合判断问题转化为2组三次Bezier曲线段的重合判断问题．文中在理论上证明了该算法的正确性，并通过若干实例验证了其有效性．

英文摘要：

The computation of curve-curve intersection is aproblem important issue in computer aided geometric design. However, the existing curve-curve intersection algorithms cannot deal with the coincident curves. Based on the coincident conditions of two cubic Bezier curves, in this paper a new algorithm presented to judge whether two cubic B-spline curves are coincident. For each B-spline curve, the algorithm first subdivides it into B6zier segments, and then determines whether two Bezier segments can be merged. By merging the adjacent or overlapping Bezier segments, the problem is converted into the coincident judgment of two sets of cubic Bezier curves. The correctness of the proposed algorithm is proved in this paper. Several experimental results demonstrate the effectiveness of the proposed algorithm.