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基于逆向工程的混合建模是目前应用较为广泛的逆向建模方法。简要介绍了以软件Geomagic Studio和SolidWorks为平台的混合建模的一般流程,通过对由不同几何特征曲面组成的模型进行混合建模为例,详细介绍了基于点云的逆向建模,并对逆向建模得到的NURBS曲面进行正向建模最终得到产品的CAD实体模型。实例表明混合建模能融合正向设计与逆向建模的优势,具有较高的建模效率以及参数化修改功能,为复杂模型的逆向设计提供了一种新的解决方法。 相似文献
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针对端盖外形特征及逆向重构中误差的主要来源进行了分析,为了获取较为精确的端盖实体模型并提高多孔类零件的建模效率,采用正逆向混合建模技术完成端盖的模型重构。重构中对端盖边界及深孔位置运用二次正向设计的方法修正了端盖在逆向建模中的误差,通过对重构后点云模型的精度校验验证了该方法的有效性,并借由3D打印技术得到了端盖的实物模型。 相似文献
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面向复杂结构零件的逆向测量规划技术 总被引:1,自引:0,他引:1
提出了一种复杂结构零件的逆向测量规划技术.基于功能-结构的层次映射,研究了复杂结构零件的元特征解耦机理,提取基本测量单元.构建包含精度特性、特征复杂度等元特征属性的信息模型及包含测量精度等的测量方法信息模型.建立元特征和测量方法匹配评价影响因素集,研究特征属性的关系模型.在此基础上,通过定性评价和模糊定量评价两个步骤得到匹配优度量化值,实现了测量方法的定量化最优选择.然后,对分散的元特征进行组合,优化整个测量过程.最后,采用此方法对汽车发动机气缸盖进行了快速逆向测量,并重构了计算机辅助设计模型.实验结果表明,该方法可以提高复杂结构零件的逆向设计效率与质量. 相似文献
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在产品设计生产过程中,有些零件无法在设计阶段直接进行理论模型设计,需要根据现场实际情况先加工多件零件,并应用于产品装配,再按照加工实物开展三维模型设计,然后进行零件批量生产。经过测量方式设计的三维模型通常与实物误差较大。但是通过逆向技术能够获得精度很高的实物的三维模型。在飞机生产过程中,通过研究逆向建模技术,对实物进行逆向扫描,采集点云数据,并基于零件特征分析进行三维模型设计,这样既提升了三维模型的设计效率,又可以很高的精度保证三维模型与实物的一致性。该文在研究过程中,选取具有一定通用特征的钣金零件和机加零件作为实验对象,应用逆向扫描技术获得点云数据,基于零件特征进行三维模型设计,通过验证两类零件均满足设计和生产需求。逆向建模技术能够应用于飞机生产过程中的模型设计和零件制造。 相似文献
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在产品的设计过程中,正向设计和逆向设计的方法在建模领域各有其特点。面对已有模型复杂的轮廓曲线及外形曲面,为了提高建模效率,根据正逆向设计的特点,吸取了正向设计和逆向设计的双重优势,提出了基于Artec Studio、Geomagic Studio和CATIA软件相结合的正逆向混合设计建模方法。此方法探索了零件的建模新途径,极大地提高模型数据的处理精度和准确性,减小了与实际物体的尺寸误差,保证了模型的精确度,为正向设计提供了前提基础。对扩展到其他工程领域具有现实意义。 相似文献
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本文围绕汽车的内饰逆向设计方法展开论述,针对在Imageware软件基础上进行设计的汽车逆向内饰方法,通过对内饰产品点云的处理,曲面的构建,曲面的质量检测等方面对逆向设计的方法和软件运用进行阐述。 相似文献
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JK—1型建筑卷扬机是一种广泛使用于建筑行业的提升设备.作者运用现代设计思想和方法对此进行了改进设计.本文着重介绍了功能分析、形态分析以及技术—经济评价法在改进设计方案制定、筛选和确定中的应用.最后给出了最佳方案与结论. 相似文献
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逆向工程(反求工程)是利用对实物测量的数据重新构造实物的计算机模型,然后利用CAD/CAE/CAM等计算机辅助技术进行分析、再设计、再加工的过程。针对汽车后视镜实施逆向工程,在给出其具体过程的同时,给出了自动、手动两种曲线(曲面)拟合的方法与过程,在产品设计与改进中具有极强的借鉴意义。 相似文献
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Hesam Samarghandy Ye Li 《The International Journal of Advanced Manufacturing Technology》2013,69(1-4):337-349
The intensive competition has forced the manufacturing industry to improve product quality and production efficiency, and meanwhile reduce production cost. Detecting potential manufacturability problems in early design stages would prevent unnecessary cost involved in re-work and/or re-design activities at later manufacturing stages. This paper presents an algorithm for determining re-design areas to feedback the designer when the design model involves machining holes and pockets using a three-axis computer numerical control machine. The algorithm takes into account the various sizes of tools and tool holders, and therefore allows a designer to test the manufacturability of their available cutters on their design models. A color-based obstacle-detecting method, based on layer-slicing of re-design areas, helps a designer to re-evaluate a design model for increasing manufacturability. Practical examples are provided as the output of the process. 相似文献
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机械运动方案相似设计研究 总被引:4,自引:1,他引:3
概念设计是产品开发过程中的决定性阶段 ,机械运动方案设计是机械产品概念设计的关键内容。本文提出了机械运动方案相似设计理论和方法 ,并对构造相似元、计算相似度、实例再设计等关键技术进行了研究 ,给出了相应的解决方法 相似文献
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A knowledge-based manufacturing and cost evaluation system for product design/re-design 总被引:1,自引:1,他引:1
R. Sharma J. X. Gao 《The International Journal of Advanced Manufacturing Technology》2007,33(9-10):856-865
Various research studies have concluded that most new design projects are actually re-design activities. This re-design may be for improvement or for reprovision of existing products. Most research efforts for providing computer tools for supporting conceptual or early design mainly concentrated on the design of new products. In practice manufacturing plans generated when an order was placed may quickly become out-dated as the manufacturing environment and constraints often change. It is therefore equally important to regenerate manufacturing plans and re-evaluate design every time a product is changed, re-designed or reordered. This project focuses on manufacturability analysis and provides re-design support for conceptual design of discrete single-piece mechanical parts with emphasis on machined processes. This limitation of implementing the prototype system for re-design activities is not a system design or methodology restriction. The condition has been imposed by the authors as a prelude to validating the system and its results. A novel hybrid approach using a combination of sequential flowchart logic and an expert system has been developed which uses a user-defined feature tree as the input for its analysis. The system allows the designer to estimate manufacturability according to criteria of time and cost, and also to explore different scenarios of parametric variation in the design. A case study has been presented to validate the system’s practicality and usefulness. 相似文献
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Developing a PDM/MRP integration framework to evaluate the influence of engineering change on inventory scrap cost 总被引:4,自引:1,他引:3
C. Ou-Yang M. C. Cheng 《The International Journal of Advanced Manufacturing Technology》2003,22(3-4):161-174
Quick response to market change has become a critical strategy for businesses in the global competitive environment. Since product design usually occupies a major time period of the product development process, shortening the time spent in the re-design stage has become an important issue for businesses. In this research, an environment integrating a PDM and an MRP application was proposed. By applying the concepts of Activity Based Costing (ABC), this environment can be used to support designers in a part re-design project to analyze inventory scrap costs. Using ARIS software, an eEPC model describing the re-design process in PDM, as well as the scrap cost analysis process, was developed. The major function of this integrated environment is to support the designer in making quick and proper decisions to reduce the inventory scrap cost of existing parts during the product re-design project. 相似文献
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分析了逆向设计与正向设计的差异,给出了逆向设计的一般流程,并结合汽车设计特点,论述了汽车逆向设计对于企业积累设计知识、明确产品定位、实现快速开发的重要性,在此基础上,将汽车逆向设计工作按内容不同细分为几个阶段,并概括总结了汽车逆向设计各阶段的主要内容。分析指出了如果汽车设计开发中逆向和正向设计之间流程设置不当,将不可避免地会给汽车正向设计带来隐患,并给出了融合汽车正向设计与标杆车逆向设计的流程建议。 相似文献