SBIR Phase I: Creating Functionally Decomposed Surface Models from Measured Data

这个小型企业创新研究(SBIR)第一阶段项目涉及从测量数据重建复杂的自由形状的问题。最感兴趣的是创建结构良好、高质量的CAD模型。有几种技术可以实现这一目标。遗憾的是，自动堆焊系统只提供粗略的近似，没有捕捉到最初的设计意图，而手动分割方法不是非常稳定，需要繁琐的工作。使用功能分解范例，对象被构建为由较小的从属特征曲面连接的大型独立主曲面的集合，例如圆角或扫掠曲面。这个项目的目的是详细阐述半自动的方法来建立对象的拓扑结构，并为各个点区域计算最佳的表面表示。重点介绍了不同的光顺方法来重新定位分段曲线网络，以及不同的约束曲面拟合算法以确保与现有曲面几何的平滑连接。该研究从几何造型的理论基础入手，通过原型实现来验证算法的可行性和有效性，该技术将显著缩短相关工业设计和制造过程的提前期，并产生更多美观的对象。主要应用将是产品设计，包括汽车、航空航天、消费品和医疗器械。改进后的产品将提供一种引入按需设计和按需工程服务的方式，从而帮助美国制造业在世界市场上更具竞争力。它还将帮助美国公司增加以客户为中心的生产，并减少产品迭代之间的时间。

This Small Business Innovation Research (SBIR) Phase I project deals with the problems of reconstructing complex freeform shapes from measured data. Of primary interest is the creation of well-structured, high- quality CAD models. Several techniques exist to reach this goal. Unfortunately, automatic surfacing systems provide only rough approximations and do not capture the original design intent, while manual segmentation methods are not very stable and require tedious work. Using the functional decomposition paradigm, objects are built up as a collection of large, independent primary surfaces being connected by smaller, dependent feature surfaces, such as fillets or swept surfaces. This project aims to elaborate semi-automatic methods to build up the topology of the object and compute optimal surface representations for the individual point regions. Emphasis is put on different fairing methods to relocate the segmenting curve network and different constrained surface fitting algorithms to assure smooth connections to existing surface geometry. The proposed research starts with theoretical ground work in geometric modeling, followed by a prototype implementation to prove the feasibility and efficiency of the algorithms.This technology should significantly shorten lead-time in related industrial design and manufacturing processes and produce more aesthetic objects. The main applications will be product design, including automotive, aerospace, consumer products, and medical devices. The improved product will help US manufacturing industry to be more competitive in the world market by providing a way to introduce design on demand and engineering on demand services. It will also help US companies increase customer-focused production and reduce the time between product iterations.