熔融沉积三维打印体外支撑设计理论与方法

Three dimensional printing, growing up very fast, makes a common person be able to carry out the manufacturing at home, and is bringing great change to the economy and the daily life. This project aims at a key bottleneck problem of the three-dimensional printing of the fused deposition, and will do research on the theories and the methods of supporting design from outside models for the fused deposition three-dimensional printing. First, this project will do research on the theories and the methods of analyzing supporting regions from outside models and calculating the reasonable printing directions so that all the necessary supporting regions can be found, and no unnecessary regions will be included. Then, the project plans to do research on the theories and the methods of self-supporting design of two categories. One is based on model segmentation, and the other one is based on model deformation. Thus, we hope the theories and the methods can satisfy different application requirements. The former one based on model segmentation with less material requires assembly, and has worse physical properties. The latter one based on model deformation has better appearance, but changes the shape of the given model. Finally, the project will focus on the theories and the methods of the supporting design from outside models to reduce the cost of the supporting material, to make it less difficult while removing the supporting model from the printed object, and to improve the success rate, the stability, and the quality of three-dimensional printing. In summary, the project aims to make contributions to improve the international competitiveness for the fused deposition three-dimensional printing.

熔融沉积三维打印让普通大众在家中就可以完成制造，其增长速度非常迅猛，正在给人类经济与生活带来巨大变革。本项目旨在针对熔融沉积三维打印的关键性瓶颈问题，研究体外支撑设计理论与方法。首先，本项目将研究外部支撑区域分析理论与方法，计算出更加合理的三维打印方向，同时希望既能够找到所有的外部支撑区域，又不把不需要支撑的区域纳入进来。然后，本项目计划从基于模型分割和基于模型变形两方面展开自支撑模型设计理论与方法的研究，从而让自支撑模型设计适应不同的应用需求。基于模型分割的自支撑模型设计最省材料，但需要组装，其物理性能相对最差；基于模型变形的自支撑模型设计的打印结果的外观最好，但改变了打印结果的形状。最后，本项目将重点研究外部支撑体设计理论与方法，减少支撑材料代价，降低支撑体的剥离难度，提高三维打印成功率、稳定性与质量。总之，本项目希望能为提高熔融沉积三维打印机的国际竞争力作出贡献。

本项目旨在针对熔融沉积三维打印的关键性瓶颈问题，研究体外支撑设计理论与方法。本项目的研究内容共分成为外部支撑区域分析理论与方法、自支撑模型设计理论与方法以及外部支撑体设计理论与方法三部分。其中第一部分外部支撑区域分析理论与方法是后两部分的基础，各研究内容的具体情况如下：.外部支撑区域分析理论与方法。本项目构建了基于中轴变换（Medial Axis Transform，MAT）的支撑区域分析理论与方法，该方法基于MAT理论，以三维模型的形体分布为主要分析依据，在原有方法的基础上，构建了快速MAT算法，可以快速获得模型的MAT分布，并在此基础上构建了深度学习网络用于对模型的外部支撑区域进行分析，为后续的支撑设计理论与方法研究提供了支持。.自支撑模型设计理论与方法。本项目从基于替换的子支撑模型设计理论与方法、基于区域扩散的和N边孔洞填充的自支撑模型设计方法两部分着手。前者是通过对模型外部支撑区域的分析结果，将需要支撑的部分通过模型替换转变为自支撑结构，本项目重点解决了替换区域与原区域间的网格质量问题。后者通过对元模型进行扩展或填充以生成相应的支撑结构，这两者在部分变更原模型形状的基础上，将模型转变为自支撑结构。.外部支撑体设计理论与方法。基于外部支撑区域的分析结果，本项目重点研发了多种外部支撑体设计方法，从图论、拓扑优化、最短路径、树链剖分等多个角度构建了相应的外部支撑体设计方法。.在技术研发的基础上，依托于实际应用需求，本项目还实现了针对熔融沉积三维打印体外支撑设计软件工具集，该工具集分为模型转化、分层与支撑3个主要部分，集成了上述研发内容成果，并封装了模型转换、分层、支撑算法，并通过北京清软海芯科技有限公司等单位生产的三维打印机为普通大众服务，成为公司旗下三维打印设计软件LogoUp 3D的依托工具集。