【作者】 黄志华；

【导师】 陆国栋；

【作者基本信息】 浙江大学 ， 机械设计及理论， 2008， 硕士

【摘要】 鞋楦是整个制鞋过程中必不可少的模具,优化鞋楦的设计对整个制鞋过程有着重要意义。为了满足鞋楦设计,本文提出通过对三维扫描鞋楦数据的预处理,得到数字化三维鞋楦模型,对该模型进行曲面生成和变形等设计,将处理完成后的鞋楦数据输出到快速成型机生产出鞋楦,从而实现了不同需求的定制。三维鞋楦模型数字化是实现三维鞋楦建模的第一步。本文第二章描述了鞋楦数字化模型获取、模型表示及特征识别。通过三维扫描获取点云数据,利用Geomagic工具将点云数据转化为三角网格模型,并以指定的文件格式保存。鞋楦CAD系统读入扫描鞋楦数据文件,通过特征识别,得到具有正确特征信息的扫描鞋楦模型。三维鞋楦模型建构是鞋楦设计的基础。预处理得到的鞋楦模型是以三角网格形式连接的散乱数据点集,不利于鞋楦变形等处理,需要将其转换为具有规则网格结构的三维鞋楦模型。论文第三章提出一种基于截面环的三维鞋楦建模技术,并详细阐述了模型曲面生成的整个过程,包括三维鞋楦模型曲面的分片生成、曲面拼接、表面光顺处理、表面误差控制等环节。建模后的鞋楦既保持了原始模型的表面特征,又能够极大地提高鞋楦变形处理的算法效率。三维鞋楦模型的变形处理是鞋楦设计的关键。第四章论述了基于特征尺寸、模板和草图三种驱动方式的鞋楦变形技术。基于特征尺寸驱动的鞋楦曲面变形以提取的特征尺寸驱动模型进行参数化变形。基于模板驱动的鞋楦曲面变形利用标准模型进行插值而进行变形。基于草图驱动的鞋楦曲面变形是以约束关系为基础,通过拖动草图上的控制点来驱动鞋楦模型变形。基于上述研究内容,本文开发了一个鞋楦CAD系统。论文第五章介绍了该系统的开发环境、工作流程,同时给出了上述研究工作的实例。最后,对项目课题研究的发展前景从技术上和应用上作了展望。更多还原

【Abstract】 Shoe-last is the essential mold in the entire shoe-making process, so to optimize the design of shoe-last for the entire shoe-making process is of great significance. In order to meet the needs of the shoe-last design, the paper has proposed that obtaining the digitized three dimensional model of shoe-last by the preprocessing for three-dimensional scan data of shoe-last, carrying on designs such as surfaces generated and deformation for the model, the data of shoe-last after the completion is exported to the rapid prototyping machine, and customizations of the shoe-last according to different needs are realized.The digitization of three-dimensional shoe-last model is the first step to achieve the three-dimensional shoe-last modeling. In this paper, the second chapter describes the capture, the model expression and the feature recognition of the shoe-last digitization model. Cloud data are obtained by three-dimensional scanning, and then the cloud data are converted into the triangle grid model using the Geomagic tool, and the datum are preserved in some format. Shoe-last CAD system gets the data file of scanning shoe-last, and obtains the scanning shoe-last model, which has the correct characteristic information through the feature recognition.The construction of three-dimensional model for shoe-last is the basis of designing shoe-last. The model of shoe-last being preprocessed, is made up of disordered data set of points that are connected by triangular mesh, which is not in favor of processing for shoe-last such as deforming and so on, so it is necessary to transform it into the three-dimensional model of shoe-last that is made up of regular mesh. In Chapter 3 of the paper, a modeling technology of three-dimensional shoe-last based on the section link is presented, and the entire process of model surface production is elaborated in detail, including the processes of the sub-surface-generation of three-dimensional shoe-last model, surface splicing, smoothing the surface, controlling the surface errors and so on. After modeling of shoe-last, not only the surface features of the original model can be maintained, but also the algorithm efficiency of shoe-last distortion processing can be enormously enhanced.Deformation of three-dimensional shoe-last model is crucial to the design of shoe-last. The fourth chapter elaborates three kinds of driving deformation technology for shoe-last that are separately based on the characteristic size, the template, and the sketch. The deformation of surface for shoe-last based on feature size driving is a method that carries on the parameterizations of the model-driven deformation by the extracted feature size. The shoe-last deformation of surface which is based on the template-driven carries on deformation by using the interpolation of the standard models. Deformation of the shoe-last surface based on the draft-drive is based on the constrain solution, and actuates the model deformation of shoe-last through dragging the control point.Based on the research content above, we have developed a Shoe-last CAD system. Chapter 5 of the paper introduces the development environment and the work flow of this system. The example of the research work above is given simultaneously.Finally, the prospect of the project research is forecast from the aspects of technology and application.更多还原