基于Virtools的减速器虚拟装配系统研究

对虚拟装配的模型结构、虚拟装配的干涉检查技术进行研究,利用UG完成了减速器的三维建模及装配模型,创建了模型的空间约束、装配路径及装配序列,通过CAD系统与虚拟装配系统之间的模型数据转换方法获取装配模型信息,最后利用Virtools软件完成减速器的虚拟装配系统开发。     

基于造型与装配过程的CAD逆向设计方法

提出基于造型与装配过程为一体的CAD逆向设计方法，介绍CAD逆向造型设计和装配过程的基本概念和原理，在小型三维机械设计CAD软件环境下，应用Visual Basic开发了三维实体参数化虚拟造型设计系统和逆向装配系统。通过建立齿轮和轴的逆向装配系统的实例，说明了应用该方法开发CAD逆向装配系统的全过程。结果表明该方法适合于形状复杂的三维实体造型和复杂系统的装配设计。     

三维CAD技术研究进展及其发展趋势综述

三维CAD软件是整个工业软件体系的核心与基础,但目前中国高端三维CAD软件市场被国外工业巨头所垄断,国产三维CAD软件在中端市场的占有率也很低,严重威胁我国工业系统的安全。为探明三维CAD发展方向,给出国产三维CAD软件高质量发展的可行路径,系统梳理了三维几何建模引擎、几何约束求解、CAD数据交换、CAD接口与二次开发、产品信息集成、设计知识处理、大规模装配、基于模型的定义等三维CAD关键技术的研究进展,探讨了其技术难点及发展方向;在深入调研国内外三维CAD软件发展现状的基础上,分析了国产三维CAD软件存在的差距及其根源;阐述了三维CAD软件集成化、智能化、云端化、专业化、一体化等发展趋势,并给出了国产三维CAD软件实现高质量发展的若干建议。     

基于逆向CAD技术实现并联机构自动化装配研究

提出了装配过程逆向CAD方法,结合Visual Basic 6.0高级语言,基于SolidWorks软件API对象及其函数,开发了并联平台自动装配系统。以线条的方式建立了各种运动副零部件的三维实体模型,并在不使用数据库技术及其相关软件的情况下,利用CAD软件自带的系列零件设计表功能,建立了一个广义上的动态数据库,在运动副杆件结构尺寸方面实现了更进一步的参数化。实践证明,对三维机械设计软件的装配建模进行二次开发,装配过程逆向CAD方法是一种行之有效的解决途径,利用该方法可以研发大型、系列化装配体建模的参数化设计系统。     

面向三维CAD的装配顺序建模系统研究

研究了面向三维CAD模型的装配顺序建模的原理、步骤和方法,先归纳出常见子装配体特征,再根据这些特征进行人机交互分析以划分装配顺序;开发了基于开目三维CAD的几何模型信息和三维CAD装配仿真模块的装配顺序建模系统;给出了使用该系统实现装配顺序规划的实例。     

CAD模型约束向多体动力学模型运动副的转换

CAD系统在动力学仿真功能上较为薄弱,而动力学仿真软件在造型方面的功能较为薄弱,因此在三维软件下建模再导入到仿真软件中进行运动学和动力学分析成为一项研究课题,而装配模型的部件在两种系统中的限制关系成为转换的难题。以挖掘机模型为研究对象,以约束和运动副为理论基础开发了转换模块,实现了模型从Pro/E系统向ADAMS系统的转换,该转换实现了约束向运动副的转换。     

变型设计中语义建模与推理方法研究

为了能够充分利用企业现有的CAD模型,提出了一种基于语义推理的变型设计方法。首先,对三维CAD信息模型和装配语义信息模型进行了研究,给出了两种模型的构建方法。在此基础上,对语义推理方法进行研究,结合相似性算法实现了CAD信息模型至装配语义信息模型的自动映射。并进一步实现了尺寸约束方程式在一定程度上的自动生成及尺寸约束传递解算。最后,以SolidWorks为三维CAD模型平台,以VC++6.0为编程语言开发出语义映射系统,并以某企业的龙门铣床的主轴箱作为例子,对该系统进行了验证。     

基于自顶向下的三维CAD特征建模及其应用

现有三维CAD工具基于自底向上建模存在不足.本文提出了自顶向下设计的概念.给出了自顶向 下的装配设计系统开发程序,提供了一个面向装配的设计环境,通过层次化的装配模型和参数化的建模技术.由产品的关键零件约束产生其它的零、部件,支持了产品从概念设计到详细设计,以Pro/ENGINEER软件为平台,减速器产品为对象进行了实际应用.     

液压集成块CAD系统的设计与实现

遵循基于阀件装配关系的设计思想，在AutoCAD 2004平台上用VBA设计开发了液压集成块三维CAD系统。软件能在三维可视环境下完成集成块的装配设计，根据生成的装配关系及连通信息自动实现集成块三维零件设计，同时可方便地生成三维零件剖切图及剖面图，使液压集成块设计更为直观、准确和快捷。     

三维CAD装配新方法探索

三维CAD软件SolidEdge通过贴合、对齐等装配关系实现各种零部件的装配,但是对于较为复杂的机构仅使用这些装配关系装配起来较为繁琐,特别是根据二次开发的特殊零件很难实现装配.三维数字装配新模式可以实现各种零部件的装配,不仅是对原装配模式的一种补充,而且还开辟了三维CAD软件装配新模式.     

计算机辅助装配工艺设计集成化系统

阐述了发展装配CAPP集成化系统的意义 ,提出了产品装配模型结构 ,讨论了装配CAPP集成化系统的原理、结构和主要技术 ,建立了DFA与装配CAD/CAPP的集成化系统框架。     

机构运动仿真的逆向设计

提出CAD逆向设计的概念，并通过建立铰链四杆机构仿真系统的实例，详细介绍了应用该方法开发仿真系统的全过程。旨在提供一种对三维CAD软件开发的新方法，从而提高自身开发三维CAD软件的能力。同时铰链四杆机构仿真系统的建立在工程机械设计中具有重要的应用价值。     

A pragmatic system to support interactive assembly planning and training in an immersive virtual environment (I-VAPTS)

Assembly planning for complex products is a difficult task requiring both intensive knowledge and experience. Computer aided assembly planning (CAAP) systems have been the subject of considerable research in recent years without achieving a wide application in manufacturing industry. In this paper an alternative approach to the generation of an optimal assembly planning scheme is presented based on the adoption of immersive virtual reality. A product is assembled from CAD models by providing a CAD interface to transfer assembly constraint information from the CAD system to a virtual environment. In the virtual environment an efficient dynamic recognition and management method based on surface geometry is employed, and a process-oriented assembly task model is established to support interactive assembly planning and evaluation. The system is implemented using an object oriented methodology, and has been successfully applied to train and guide the assembly workers in a pump assembly process.     

Computer aided geometric feasible assembly sequence planning and optimizing

Assembly sequence planning (ASP) is the foundation of the assembly process planning and design for assembly (DFA). In ASP, geometric feasibility is the prerequisite in the valid assembly sequences searching. The assembly precedence relations’ (APRs) deriving and fulfilling are the essential tasks in the geometric feasible assembly sequence planning. In this paper, a systematical approach called geometric constraint analysis (GCA) is proposed and the corresponding software system is developed and integrated with CAD system. Using this system, only with a few mouse clicks on CAD draft, assembly precedence relations (APRs) can be derived correctly and completely. Then, all the geometric feasible assembly sequences can be inferred out automatically. Moreover, an optimal algorithm is designed and realized in the GCA method, by which, the most optimal assembly sequence in terms of the operation convenience can be found out from the immense geometric feasible sequences. An erratum to this article can be found at     

面向大型复杂产品的虚拟装配技术研究

针对大型复杂产品在装配生产组织形式、人的参与程度、装配工艺流程的优化、装配人员培训和示教等方面的特点,分别进行了虚拟装配关键技术的研究。重点探讨了考虑人体活动的新型虚拟环境技术、CAD系统和虚拟装配系统的数据集成技术、装配工艺的生成及其优化技术、工艺文件生成和现场示教技术等4个方面。最后给出了开发的虚拟装配原型系统在某型号复杂产品中的应用实例。     

An effective integration approach toward assembly sequence planning and evaluation

An integration strategy for assembly sequence planning and sequence scheme evaluation is proposed. This strategy can be used to plan a reasonable assembly sequence, to optimize a sequence scheme, and to predict whether a collision will occur between the assembly tool and assembled components by considering factors like target components and assembly resources. A hybrid method is presented for assembly sequence modeling that combines human-computer interactive operations to manually build a hierarchical assembly sequence main model and a hybrid graph method to automatically generate sub-assembly sequence schemes of the main model. An optimization algorithm based on time-cost is introduced to handle a best candidate components selection. This relieves the problem of limited capability found when handling large size assembly models with traditional methods. The essential issues involved in system implementation are discussed as well; these include a representation method for the assembly consequence model, an optimization model of assembly sequence planning, and an object-oriented system architecture model employed with multi-agent technology for visually evaluating the assembling process. This system, KM computer-aided assembly process planning, KMCAAPP, has been developed on the basis of our previous work, KMCAD3; KMCAAPP uses the presented approach. KMCAAPP can be integrated with CAD model from KMCAD3D. A case study shows that the presented approach can use large CAD assembly models and delivers a feasible and effective way to integrate the assembly sequence planning process with scheme evaluation by visually evaluating the assembling process. This allows the identification of design errors in a timely manner and mitigates economic loss.     

齿轮实体参数化逆向虚拟造型设计的方法

提出实体参数化逆向虚拟造型设计的方法，介绍应用该方法开发齿轮3维实体参数化虚拟造型设计系统的过程。旨在提供一种对CAD软件开发的新方法，使设计者掌握运用该方法进行实际开发，从而提高开发CAD软件的能力。     

Three dimensional modeling of the working linkage of load-haul-dump loader

3-dimensional (3D) modeling approach of the working linkage of load-haul-dump (LHD) loader has been presented to implement 3D computer aided design (CAD) and manufacture. The modeling approach is described in detail with application examples. The major issues in implementing modeling are discussed. Research work is focused on integration of basic modeling operations in the HELIX design system with modeling methods proposed in this work to achieve part modeling, assembly modeling, and assembly analysis of the working linkage. Part modeling operations in the HELIX design system and proposed compound modeling method are used together to design the parts in 3-dimensions. Assembly modeling operations in the HELIX design system and proposed feature-based modeling and assembly method from top to bottom have been integrated to assembly parts into an assembly tree structure in 3-dimensions. Assembly analysis operations in the HELIX design system have been proposed to find out the geometric connection, express the spatial dimension and make the interference check in the assembly model. This approach can be used for all kinds of 3D modeling of the working linkage of LHD loader.     

装配CAD/CAPP集成方法与系统实现

本文提出了基于 Ｓ Ｔ Ｅ Ｐ 的产品装配数据模型和装配 Ｃ Ａ Ｄ／ Ｃ Ａ Ｐ Ｐ 集成系统框架,并研究了 Ｅ Ｘ Ｐ Ｒ Ｅ Ｓ Ｓ数据模式和集成系统在关系数据库上的实现方法,最后,给出了应用实例。