逆向工程中曲面重构算法研究与实现

RESEARCH ON THE ALGORITHM OF SURFACE RECONSTRUCTION IN REVERSE ENGINEERING

给出了基于坐标测量机测得的海量数据重新构造样板物体的数字化表面模型的算法流程。该算法首先利用部分测量数据构造张量积的Ｂ样条网格曲面，通过确定适当的检查点，并计算检查点到所构造的Ｂ样条网格曲面间的距离，从而控制重构曲面的构造精度。讨论了与文中算法相关的空间点到ＮＵＲＢＳ曲面间的距离计算等问题。给出了１个工程应用实例，表明该算法稳定可靠、效率较高。

Surface reconstruction is the key algorithm of reverse engineering. An effective reverse engineering algorithm should not only be able to model complex object shapes and convert the models to other CAD systems, but also be able to control the accuracy of the models generated. This paper addresses a surface reconstruction algorithm, which reconstructs the digital surface model of sample objects based on the cloud points. In the algorithm, part of the inspection points is first used to construct a tensor product B spline mesh surface, which roughly fits the sample object. An accurate control algorithm is then introduced to improve the generated B spline surface till it is within the given tolerance. The calculation of the distance between a 3D point and a B spline surface, which is related with the algorithm, is also discussed. A practical application instance, which demonstrates the high stability and efficiency of the proposed algorithm, is given at the end of the paper.