关 键 词：

酸奶 逆向 造型 研究

资源描述：

购买设计请充值后下载，，资源目录下的文件所见即所得，都可以点开预览，，资料完整，充值下载可得到资源目录里的所有文件。。。【注】：dwg后缀为CAD图纸，doc,docx为WORD文档，原稿无水印，可编辑。。。具体请见文件预览，有不明白之处，可咨询QQ:12401814

内容简介：

Reverse Engineering in the application of product designThe application that is in expatiate contrary engineering in the product design with develop the term, effectively of solution shape design with follow-up engineering design, manufacturing link mutually the problem that become disjointed, put forward on sowing in adopt in the product design process the Pro/Designer have no with Pro/Engineer to sew to connect method, design for the industry product shape with the in the late engineering makes of linking up and developing a new path, the process of its design process is a line of for valid measure that product design systematize to provide, from but shortened the product design development, period, realizes the product shape design of systematize.1 reverse engineering of the content and scope of applicationWith the development of computer technology, CAD technology has become a product design staff an important tool for research and development, of which three-dimensional modeling technology has been widely used in manufacturing products and mould design, program evaluation, automated processing and management of all aspects of maintenance. In the actual development of the manufacturing process, design staff to receive technical information may be all kinds of data types of three-dimensional model, but a lot of time, it is from the upstream manufacturers have the physical product model. Designers need to adopt a certain way, this kind of information into the CAD model, which applied to reverse engineering (Reverse Engineering). The so-called reverse engineering, refers to a means of measuring the physical model or measured, according to survey data 3D modeling methods through physical reconstruction of the CAD model of the process.Reverse engineering technology and traditional design is very positive difference. And reverse engineering is starting from a prototype and then obtain three-dimensional digital model of the product, make it possible to further use of CAD / ACE / CAM and CIMS and other advanced technology to process.In general, reverse engineering products, including the shape reverse, the summation of the anti-reverse, and several other materials, in the industrial field in the practical application, including the following: (1) the design of new parts, mainly for the product imitation or modified design. (2) Have been parts of the copy, reproduce the original intent of the design of the products. (3) damaged or worn parts of the reduction. (4) digital model of detection, for example, the deformation of product testing, welding quality, as well as a model for comparison. Reverse engineering technology for the rapid design and manufacturing provided a good technical support ，it has become an important manufacturing information transmission and concise way. And the traditional product design, market research in general, the development requirements table after the plane started to sketch the idea of forming a little integrity of the program, started drawing three-dimensional map, then completely stereotyped as required draw results map, three view or create a simple model. In the process of design, engineering and technical personnel needs, product modeling staff and workers work together, using samples physical model to express the idea of designers, but for every kind of a program have produced samples, to pay a lot of labor, There is a low accuracy, modify adjustment difficulties, the design cycle length and cost of higher issue.2 CAD technology in product design issues.The development of computer technology, brought about the third wave of technological revolution, computer-aided design (computer aided design, referred to CAD) technology is the computer industry in the area of application of the most active one. It sets numerical simulation, geometric model of processing, graphics, database management systems, and other aspects of technology integration, the abstract, flat, separation of the specific object of design, visualization, it can through the virtual reality technology The product of the shape, texture, color, and even brought process demonstrated, and can product design process, through data management, and systematic, standardized, and this is industrial design and integration of CAD technology will inevitably the basis.Reverse engineering software implementation of the conditionsAt present, relatively commonly used generic reverse engineering software Surfacer, Delcam. Cimatron to Strim. The specific application of reverse engineering system is mainly the following: Evans for the development of machine parts to identify the reverse engineering system; Dvorak development of the imitation parts of the old reverse engineering system: HHDanzdeCNC CMM system. These systems to reverse the practical problems in the design process, greatly facilitate the design staff. Besides, Some large CAD software is gradually provided for reverse engineering design module. Such as Pro / E and the ICEM Surf Pro / SCANTOOLS module can accept and orderly points (measurement line), can also accept the point cloud data. UG as other software, with versions of the increase, reverse engineering module is gradually enriched up. These software reverse engineering for the development of the implementation of the software conditions. These software and despite some relatively high-end design software, already the product of complex design and modeling exaggerated features, but the art designers to master and use of such software, so far is not an easy task. So in the structural design of the major designers who are mechanical engineers, design and way of thinking completely different from the modeling designer, their thinking is a fully consistent with the design of mechanical design standard way of thinking. So, how will the two designs in the design of the products are in combination, and receive better integrate and better processing from design to completion of the conversion process of our product design to consider the issue.3 product design - CAD reverse engineering technology(1) Pre / E of the design parameters of the projectParametric Design (Parametric) (also known as drive size Dimension-Driven) is in the practical application of CAD technology in the subject, it will not only CAD system is an interactive graphics capabilities, but also with automatic mapping capabilities. Currently, it is the application of CAD technology in the field of a major, Judai further study the issue. Use of the design parameters of the development of the means for product design system will enable designers from the large number of heavy and trivial mapping out relief work, can greatly improve the design speed, and reduce the storage of information. Parametric design, the key is to extract the geometric constraints and expression, and the parameters of constraint solving geometric model of the structure. 1988, the United States launched the first technology companies parameters of the design parameters of CAD system Pre / Engineer (referred to Pre / E) to give full expression to their common in many parts, components, the simple design of the advantages. Its main features are: Feature-based, full-size constraints, all data related to the size of drive to amend the design. So that we can use PTC: the companys industrial design software Pre / Designer (referred to Pre / D) of surface design, the Pre / D and Pre / E is using the same database, is the seamless connection between the two, thus Design modeling designers and structural engineers can better collaboration(2) Pre / D surface design capabilities for industrial designers and those who want to build surface model for the engineering staff, Pre / I is precisely the tools they need, Pre / D can build high-quality free surface model, and Can easily switch to the other based on the manufacturing engineering CAD system. Pre / D to create a true and accurate geometry, the use of the more easily it can create a model to shorten the design cycle. Pre able to use visual aesthetic requirements and die manufacturing process in the engineering requirements combined with a very good, this point in the creation of free surface model now in the process was particularly notable.(3) Pre / D and Pre / E of the rumored pumped Pre / Designer and Pre / Engineer data exchange between There are two ways: one is with the Pre / Engineer direct exchange of data and another is a way to document and the Pre / Engineer data exchange. (4) three-dimensional modeling complex product design for the CAD application form decorative strong, especially products containing complex surface, you can use the Pre / D and Pre / E combination, modeling designer in the Pre / D inside do ID, so Surface modeling, directly from the Pre / I started in the Pre / E, the data lead to the Pre / E designers from the structural design of the structure of the entire design process of structural design or even all done, the customers request or designer Local to the program to make changes, then only in the Pre / D changes inside, to better keep good again after the original name given to Pre / E, then Pre / E has also been changed, but do not have to redo the structure (of course, to amend For structural conditions for the existence of, the father of characteristics that it will not be a problem).Over the years, the development of the traditional industrial products are to follow strict form of research and development process: from the idea of demand for products, features and specifications of the expected target identification, then to the various components for the design, manufacture, assembly, testing performance. Each component is retaining the original design, the design usually to CA in the form of documents to save. This development model known as scheduled mode (Pre-scriptive Model), the development of such projects also known as positive work (Forward Engineering). However, with the level of industrial technology upgrading and improving the standard of living, Any GM products in the consumer demand for high-quality, functional needs of the market has ceased to be competitive to win the only condition. Products not only to advanced features, and more focused on modeling the appearance of products, this is not the traditional mechanical engineers to the competent. Designers to shape the way through the manual model, for example: wax model, wood model, cast, clay model, engineering plastics, etc.-and then three-dimensional measurement methods generate free surface of the CAD file, which is the so-called Reverse engineering (Reverse Engineering, RE). Then put in front of the designer and manufacturer of the physical kind, will need physical model into a CAD model, as product information model is the realization of CAD / CAM technology seamlessly create the key.Reverse Engineering (Reverse Engineering) in the absence of design drawings or design drawings incomplete and not the CAD model and in accordance with the existing parts of the model (or sludge prototype model), the use of digital technology and CAD technology re-structure the CAD model And cloning to create physical products or processes. Project is positive from the CAD model to the physical model into the process, and reverse engineering is from the physical model to the CAD model of the transformation process, both the design process just the opposite, reverse engineering and forward the application of different areas, with the Digital measurement of the rapid development of technology, reverse engineering in the manufacturing sector of the increasingly widespread and mature, on the reverse engineering of CAD has also become one of the hot areas of research.4 modeling technology, including reverse engineering from the measurement data to the CAD model of a set of technical steps can be summed up in the following several aspects of key technologies: (1) measurement data processing - As the number of measurement equipment by the wider use of massive data point (in millions of orders of magnitude) access to a very easy matter. 1000000 data regardless of the person or read data, and other aspects of reconstruction model for us is very inconvenient, and in need of reconstruction CAD model before the measurement data pretreatment. (2) grid model construction three grid model of reverse engineering is commonly used in the model that way. three grid model can easily express complex shape of the objects surface, while grid model for the reconstruction surface model is a very good foundation model. (3) basic model surface structure - reverse engineering modeling is the ultimate goal of universal CAD system to provide a valuable basic surface model, in the final completion of GM products in the CAD system model of reconstruction. So reverse engineering of the basic surface model for the Reconstruction of high-quality reconstruction of the CAD model is very important. (4) model of quality - reverse engineering model is based on measurement data in the reconstruction CAD model. In the reconstruction process because of the various data (such as compression) so that data back to the inevitable errors. The ultimate CAI model is in error to allow the evaluation of the accuracy of reconstruction is an important indicator of the quality of model one. Following this will be a few aspects of the systems described.4.1 Data pretreatment technology Now with three-dimensional scanning equipment development, the measurement data are also increasing the number of points, with millions of data points measured in the paper is already very common. So many data points, the benefits are obvious, able to model all the characteristics of the small acquisition, but processing system, it is a lot of obstacles. This will not only greatly increase the systems capacity, but also reduces efficiency, which will affect the whole process of reverse engineering modeling. Therefore, the measurement data pretreatment reverse engineering modeling now become an important aspect of technology. Survey data preprocessing, in addition to the large amounts of data compression, but also to remove the noise generated in the scan data. No matter how advanced measuring equipment, the impact of noise is always inevitable. Although not much noise points, but the impact of noise or great, the work of removing the noise generated model can greatly improve the quality. Because the shape of certain models more complicated, often unable to get a scan all the data. In this way, a model of the measurement data have many pieces, so in model building, must be multi-block data connection, integration into a model. The process works in reverse as in the Register, that is re-positioning data.4.2 grid model construction Grid model in the reverse engineering of a wide range of applications. Measured data points we generally referred to as point cloud. Point cloud data does not include any topology information, in order to reconstruction surface model and rapid prototyping (Rapid Prototype Manufacture, RPM), and other processing needs we need to point cloud data constructed on the basis of triangular grid model. 1.30 Mesh topology contains a wealth of information that can be used, such as special Reconstruction of the levy, such as surface divided post-processing Club. grid can also show a real model of the shape, can achieve good visual effects. In addition, the triangle enough detailed grid can be directly used for processing parts. According to deal with the object and the use of different measuring techniques and tools, reverse engineering CAI modeling content can be divided into two aspects: one is to examine the entire body of CAD modeling, the other to deal with a complex of the main characteristics of CAD surface modeling. It also determines the triangular grid model of the construction method has two main categories. The whole body of the CAI) modeling, mainly in the field of medical image visualization applications. This kind of research more and relatively deep, is generally used CI, access to facilities such as the organ section contour, and then from these contour triangular grid structure, and its main difficulty is the handling of the bifurcation and Holes The model. According outline cross-section of this structure of the triangular grid model algorithm is now very mature and can achieve high efficiency. Modeling a large number of mechanical parts, are generally dealt with rehabilitation of the surface of the CAD modeling. Many aspects of this method, but the effect is not very satisfactory, algorithms are from a seed triangle, traverse around the point, to build triangular grid. Now is the algorithm needs to be raised the efficiency and quality of the grid. Most of the triangulation method is not the original data points of the interpolation algorithm, which caused a triangular grid model with the original data points of error, this error will be accumulated up to the surface reconstruction.4.3 Surface ReconstructionFree surface model in reverse engineering products play an important role modeling, because of free-form shape of a flexible, in aviation, aerospace, automotive, mould and other industries a large number of applications, at the same time, these industries are also reverse engineering applications in important areas, based on free Surface Reconstruction has been a model of reverse engineering CAD important area of research. Surface Reconstruction (also known as surface modeling) through modeling can be separated from the measurement data for changes in the reconstruction surface, surface fitting interpolation, including surface and surface approximation, surface Interpolation demands Interpolation the surface strictly Through the data points; surface approximation is based on the data structure of a discrete surface, so that these points in some sense the most close to the surface by the structure. Based on different forms of surface topology, the common surface reconstruction in two ways. Bezier surface to 1.30 based on the tripartite domain surface construction method, and B-spline 101 NURBS surface and based on the four sides domain surface constructed. Based on the 1.30 Bezier surface of the triangular domain surface constructed. Dealing with the basic idea is to be dealt with the original number considered as a whole. First constructed in accordance with point cloud summer triangular grid and building a triangular grid, the use of 1.30 Bezier surface in the grid on the basis of constructing smooth surface 121. 1.30 Bezier surface interpolation in the triangular grid of each triangle on the initial structure of the three variables 1.30 Bezier patch, and then each triangle patch up to four bands, and then each patch for CT (clough - tocher) segmentation, and then adjust each patch of the control points, so that the entire surface to a combination of geometric order (GCI) a row.4.4 Based on the characteristics of the model reconstructionSince reverse engineering is the subject of dealing with three-dimensional space data, how the reconstruction process in the surface model and accurately reproduce the characteristics of products, reverse engineering is the product model can comprehensively CAD system in general an important symbol. Now the reverse engineering, especially in the Reconstruction of general machinery parts, one after another to automatically extract model characteristics. Not only automatically extracted from the characteristics of products, such as bevel, the transition surface, Geng Shiba based on the characteristics of the thinking of food to the various aspects of reverse engineering, reverse engineering feature extraction as a supplementary means of modeling. In the reconstruction of the main features of the redevelopment There are two ways: First, based on the characteristics of point cloud data from the second grid model is based on the feature extraction. Based on the point cloud feature extraction algorithms based on point cloud data partial differential geometry of the feature extraction of its characteristics, and these characteristics based on the triangular grid construction, according to the data points measured in accordance with geometric features plug into triangular grid in the realization of grid breakdown, so are the grid in the dramatic changes in the local collection, changes in the local gentle sparse. Can greatly improve the structure of the triangular grid efficiency and quality. Based on the triangulation from characteristics. With a mesh topology, can be more than the point cloud data features. 1.30 grid model of feature extraction can greatly improve the process of reverse engineering products in the shape of the surface area of automatic level. Because under normal circumstances, a complete product surface with a surface model can not fully express the need for a combination of multiple surface expression, according to separate characteristics, can make a more rational division of the surface, a higher quality of the surface.Reverse engineering is a pioneering, practical, comprehensive and highly technical, reverse engineering technology has been widely applied to the development of new products and old parts of the reduction and product testing, it not only to digest and absorb the physical prototype, and can Laws designed to re-create new products. This CAD technology product design, means not only means that the design changes, and changes in the industrial design way of thinking. Promote the manufacturing industry from product design, manufacturing technology management to a series of deep, comprehensive and far-reaching changes, this is product design, manufacturing products of a technological revolution, the systematic design of products, shorten product development cycle, So as to create a practical, economic, aesthetic and pleasant products.逆向工程在产品设计中的应用本文在阐述了逆向工程在产品设计中的应用范围和发展条件，有效的解决造型设计与后续的工程设计、制造环节相脱节的问题，提出了一种在产品设计过程中采用Pro/Designer与Pro/Engineer无缝连接的方法，为工业产品造型设计与后期的工程制造的连贯开辟了一个新的途径，其设计流程的过程为产品设计系统化提供行之有效的措施，从而缩短了产品设计开发周期，实现了产品造型设计的系统化。1 逆向工程的内容及其应用范围随着计算机技术的发展，CAD技术已成为产品设计人员进行研究开发的重要工具，其中的三维造型技术已被制造业广泛应用于产品及模具设计、方案评审、自动化加工制造及管理维护各个方面。在实际开发制造过程中，设计人员接收的技术资料可能是各种数据类型的三维模型，但很多时候，却是从上游厂家得到产品的实物模型。设计人员需要通过一定的途径，将这些实物信息转化为CAD模型，这就应用到了逆向工程(Reverse Engineering).所谓逆向工程技术，是指用一定的测量手段对实物或模型进行测量，根据测量数据通过三维几何建模方法重构实物的CAD模型的过程。逆向工程技术与传统的正向设计存在很大差别。而逆向工程则是从产品原型出发，进而获取产品的三维数字模型，使得能够进一步利用CAD/ACE/CAM以及CIMS等先进技术对其进行处理。一般来说，产品逆向工程包括形状反求、工艺反求和材料反求等几个方面，在工业领域的实际应用中，主要包括以下几个内容:(1)新零件的设计，主要用于产品的改型或仿型设计。(2)已有零件的复制，再现原产品的设计意图。(3)损坏或磨损零件的还原。(4)数字化模型的检测，例如检验产品的变形分析、焊接质量等，以及进行模型的比较。逆向工程技术为快速设计和制造提供了很好的技术支持，它已经成为制造业信息传递的重要而简洁途径之一。而传统的产品造型设计，一般是在市场调研，制定需求表之后，先展开平面简图的构思，形成稍微完整的方案之后，开始绘制三维简图，完全定型后再根据需要绘制效果图、三视图或制作简易的模型。在造型设计的过程中，需要工程技术人员、产品造型人员与工人的通力合作，用样品实物模型来表达设计者的构思，但对每一种方案都制作实物样品，要付出大量的劳动，还存在着精度低、修改调整困难、设计周期长及成本费用高等问题。2 CAD技术应用于产品设计计算机技术的发展，带来第三次技术革命浪潮，计算机辅助设计(computer aided design,简称CAD)技术则是计算机在工业领域应用中最为活跃的一支。它集数值计算、仿真模拟、几何模型处理、图形学、数据库管理系统等方面的技术为一体，把抽象的、平面的、分离的设计对象具体化、形象化，它能够通过“虚拟现实”技术把产品的形状、材质、色彩，甚至加工过程淋漓尽致地表现出来，并能把产品的设计过程，通过数据管理，实现系统化、规范化，这正是工业设计与CAD技术必然结合的基础所在。逆向工程技术实施的软件条件目前，比较常用的通用逆向工程软件有Surfacer, Delcam. Cimatron以Strim。具体应用的反向工程系统主要有以下几个:Evans开发的针对机械零件识别的逆向工程系统;Dvorak开发的仿制旧零件的逆向工程系统:H.H.DanzdeCNC CMM系统。这些系统对逆向设计中的实际问题进行处理，极大地方便了设计人员。此外，一些大型CAD软件也逐渐为逆向工程提供了设计模块。例如Pro/E 的ICEM Surf和Pro/SCANTOOLS模块，可以接受有序点(测量线)，也可以接受点云数据。其它的象UG软件，随着版本的提高，逆向工程模块也逐渐丰富起来。这些软件的发展为逆向工程的实施提供了软件条件。而这些软件相对与尽管目前一些高端的设计软件，已经具备了产品复杂造型的设计与渲染功能，但要艺术类的设计师掌握并运用这类软件，至今还不是一件容易的事。所以从事结构设计的设计师们大都是机械工程师出身，设计的思维与方式完全不同于造型设计师，他们思维是一种完全符合机械设计标准的设计思维方式。那么,两种设计将如何在产品的设计中得到结合，且得到较好的结合，并且更好地完成从设计到加工程序的转换?成为我们进行产品设计所要考虑的问题。3 产品设计-逆向工程CAD技术(1) Pre/E参数化设计在工程中的应用参数化设计(Parametric)(也叫尺寸驱动Dimension-Driven)是CAD技术在实际应用中提出的课题，它不仅可使CAD系统具有交互式绘图功能，还具有自动绘图的功能。目前它是CAD技术应用领域内的一个重要的、且待进一步研究的课题。利用参数化设计手段开发的专用产品设计系统，可使设计人员从大量繁重而琐碎的绘图工作中解脱出来，可以大大提高设计速度，并减少信息的存储量。参数化设计的关键是几何约束关系的提取和表达、约束求解以及参数化几何模型的构造。1988年，美国参数技术公司首先推出参数化设计CAD系统Pre/Engineer(简称Pre/E)充分体现出其在许多通用件、零部件设计上存在的简便易行的优势。它的主要特点就是:基于特征、全尺寸约束、全数据相关、尺寸驱动设计修改。这样我们可以采用PTC:公司的工业设计软件Pre/Designer(简称Pre/D)进行曲面设计，由于Pre/D与Pre/E采用的是同一数据库，两者之间是无缝连接的，因而在设计中造型设计师和结构工程师可以更好的协作(2) Pre /D的曲面设计能力对于工业设计人员和那些想构建曲面模型的工程人员来说，Pre/I正是他们需要的工具，Pre/D可以构建高质量的自由曲面模型，并且可以很容易的转换到其它基于制造工程的CAD系统中。Pre/D能够创建真实而精确的几何体，利用它可以更加容易的创建模型，缩短设计周期。利用Pre可以把视觉上的美学要求和模具制造过程中的工程要求很好的结合起来，这一点在创建自由曲面模型的过程中现得尤其显著。(3) Pre /D与Pre/E之间的致据传抽Pre /Designer与Pre/Engineer之间交换数据有两种方式:一种是与Pre/Engineer直接交换数据，另外还有一种就是以文件的方式与Pre/Engineer交换数据。(4) 造型复杂产品三维设计的CAD应用对于造型装饰性强，特别是包含复杂曲面的产品，可以使用Pre/D与Pre/E组合起来进行，造型设计师在Pre/D里面做ID、做曲面建模，直接从Pre/I里启动Pre/E，把数据导到Pre/E由结构设计师进行结构设计，在整个设计过程中甚至结构设计全部做完了，由于客户的要求或设计师对方案的局部要进行更改，这时只须在Pre/D里面改动，改好后存好再原名称送给Pre/E，那么Pre/E里也得到改变，而结构不用重做(当然修改要使结构有存在的条件，即它的父特征不会有问题)。长久以来，工业产品的传统开发方式均是遵循严谨的研发流程:从产品需求的构思、功能与规格预期指标的确定，进而到各个组件的设计、制造、组装、性能测试等。每个组件都保留有原始的设计图，此设计图目前通常以CA文件的形式来保存。这种开发模式被称为“预定模式”(Pre-scriptive Model)，此类开发工程亦通称为“正向工程”(Forward Engineering).然而 ，随着工业技术水平的提升以及生活水准的提高，任何通用性产品在消费者对于高品质的要求下，功能上的需求已不再是赢得市场竞争力的唯一条件。产品不单单是功能要先进，而且更多着重于产品的外观造型，这已不是传统的机械工程师们所能胜任了。设计师们先通过手工方式塑造出模型，例如:蜡模、木模、石膏模、粘土模、工程塑料模等等，然后再以三维尺寸测量的方式生成自由曲面的CAD文件，这就是所谓的“逆向工程”(Reverse Engineering,RE)。这时摆在设计者和制造者面前的是实物样件，需要将实物模型转化为CAD模型，因为产品信息模型是实现CAD/CAM无缝制造技术的关键。逆向工程 (ReverseE ngineering)是在没有设计图纸或者设计图纸不完整以及没有CAD模型的情况下，按照现有零件的模型(产品原型或油泥模型)，利用各种数字化技术及CAD技术重新构造CAD模型而克隆或创造实物产品的过程。正向工程是从CAD模型向实物模型转化的过程，而逆向工程则是从实物模型向CAD模型的转化过程，两者的设计流程正好相反，逆向工程和正向工程有不同的应用领域，随着数字化测量技术的飞速发展，逆向工程技术在制造业中的应用日益广泛、成熟，关于逆向工程的