使用平面结构光扫描仪对自由曲面检验的视点规划(中文5000字,英文6000字)
摘要
本文提出了一种基于模型的视点自动规划方法，该方法通过使用平面结构光扫描仪可以实现自由曲面检测的高精度和高效率。立体光刻格式是一种广泛应用的工业标准。该方法包括4个步骤：拓扑重建、网格重建、确定扫描方向和视点生成。第一步，根据设计的数据结构重构曲面模型的拓扑结构，在此基础上开发了一种邻域搜索算法。在第二步中，将曲面模型中的大面分割成若干小面，以便于进行视点规划。第三步，结合总面积和法向量约束，采用邻域搜索算法对视点初始扫描区域进行分组。相应地，扫描方向由初始扫描区域内小平面的法向矢量决定。在第四步中，视点的位置、方向和最终扫描区域由4个扫描约束确定，即视野、工作距离范围、视角和重叠。实验结果验证了该方法的有效性和优越性。
关键词：自由曲面；三维测量；结构光扫描仪；立体光刻；视点规划
Viewpoint Planning for Freeform Surface Inspection Using Plane Structured Light Scanners
Abstract: This paper proposes an automatic model-based viewpoint planning method, which can achieve high precision and high efficiency for freeform surfaces inspection using plane structured light scanners. The surface model is utilized in stereolithography format, which is widely used as an industrial standard. The proposed method consists of 4 steps: topology reconstruction, mesh refinement, scan direction determination and viewpoint generation. In the first step, the topology structure of the surface model is reconstructed according to a designed data structure, based on which a neighborhood search algorithm is developed. In the second step, big facets in the surface model are segmented into several small ones, which are suitable for viewpoint planning. In the third step, an initial scan region of a viewpoint is grouped by the neighborhood search algorithm combining with total area and normal vector restrictions. Accordingly, the scan direction is determined by the normal vectors of facets in the initial scan region. In the fourth step, the position, the orientation, and the final scan region of the viewpoint are determined by 4 scan constraints, i.e., field of view, working distance range, view angle and overlap. Experimental results verify the effectiveness and advantages of the proposed method.
Keywords: Freeform surface, 3D measurement, structured light scanner, stereolithography (STL), viewpoint planning. |
