Point cloud based design and manufacturing

基于点云的设计和制造

• 批准号: 170374-2007
• 负责人: Spence, Allan
• 金额: $ 1.42万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=361779
• 关键词: Point; cloud; based; design; manufacturing

Conventional CAD/CAM software uses simple "CSG" block, etc. primitives combined with Boolean intersect, etc. operations to create 3-D models.  Sculptured B-spline curves and surfaces can be added, and "evaluated" to yield a topological set of "B-rep" bounded, volume enclosing surfaces.  In practice, the CSG to B-rep evaluation process involves inexact surface/surface intersections, and floating point round-off based exchange reliability problems remain.  Concurrently, stereo vision and laser triangulation systems, used to digitize design concept models, etc. into dense point clouds, have grown in acceptance.  These point clouds are converted to fitted B-spline surfaces and "faired" to smooth out curvature "bumps".  Use of B-splines reduces data storage requirements, and is compatible with the existing IGES/STEP exchange standards.     Ultimately, however, CAD models are converted back to point style representations.  Graphics hardware is based on rapid display of polygons that are created by "tesselating" from the B-rep model.  For manufacturing, Rapid Prototyping machines require STL triangle based file representations.  Ultimately, Computer Numerical Control (CNC) machining requires creation of tool paths that consist of (short) linear motions.  Their inherent reliability, combined with ever increasing computer speed and memory availability, has created a CAD research community trend away from CSG/B-rep and B-spline models to wholly point cloud representations.  The proposed research will harness this emerging trend, and extend early but successful applicant research from stereo vision and laser triagulation based sheet metal strain analysis to more general surface gray level and color measurement, point cloud based collision detection, and rapid prototype surface coloring using a 3-D Coordinate Measuring Machine (CMM) mounted inkjet printer head.  Additional potential applications include electrochemical etching for sheet metal and copper printed circuit boards, Computer Aided Tissue Engineering (CATE) by inkjet cell deposition, and haptic surgery planned using medical Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scan data.

常规的CAD/CAM软件使用简单的“ CSG”块等。原始块与布尔相互作用等组合使用。创建3-D模型。可以添加雕刻的B-Spline曲线和表面，并进行“评估”以产生拓扑组的“ B-REP”有界的体积封闭表面。在实践中，CSG到B-REP评估过程涉及不精确的表面/表面交集，并且基于浮点圆形的交换可靠性问题仍然存在。同时，用于将设计概念模型等数字化成密度点云数字化的立体视觉和激光三角剖分系统已成长。这些点云被转换为拟合的b-spline表面，并“盖好”以平滑曲率“颠簸”。 B-Splines的使用会降低数据存储要求，并且与现有的IGES/Step Exchange标准兼容。但是，最终，CAD模型转换回点样式表示。 Graphics硬件基于通过B-REP模型“镶嵌”创建的多边形的快速显示。对于制造，快速原型制造机需要基于STL三角形的文件表示。最终，计算机数值控制（CNC）机械需要创建由（短）线性运动组成的工具路径。它们固有的可靠性，加上不断提高的计算机速度和内存可用性，从CSG/B-REP和B-Spline模型到完全点云表示，就创造了CAD研究社区的趋势。拟议的研究将利用这一新兴趋势，并扩展了早期但成功的应用研究，从立体视觉和激光三体金属应变分析到更通用的表面灰度和颜色测量，基于点云的碰撞检测以及使用3-D坐标测量机（CMM）安装的Inkjet Printer Printer Printer Head的快速原型表面着色。其他潜在的应用包括用于钣金和铜印刷电路板的电化学蚀刻，通过喷墨细胞沉积进行的计算机辅助组织工程（CATE）以及使用医学计算机断层扫描（CT）和磁共振成像（MRI）扫描计划计划的触觉手术。