Creo产品装配成功率预测系统开发

为了解决在产品设计阶段对产品装配精度与装配成功率进行预测的问题,针对装配体模型,基于公差分析理论,运用VS2010与Matlab混合编程技术,开发了Creo环境下的装配成功率预测系统。该系统可以对装配体约束信息、材料特征、形状特征、精度信息(包括尺寸精度、几何精度、表面精度)等进行自动提取,基于极值法、概率法和蒙特卡罗法等对装配体进行公差分析,基于蒙特卡罗法进行装配体模型装配精度的自动计算和装配成功率预测,最后以某齿轮装配件为研究对象对系统进行了测试应用。结果表明,该系统可以便捷、准确地实现产品装配成功率的预测。     

基于本体的概念设计产品信息模型研究

分析了基于本体的概念设计功能-行为-结构框架,对概念设计产品信息模型进行了研究,提出了在结构层引入装配特征描述机构间装配设计信息,为概念设计阶段的产品结构信息传递到后续的设计阶段提供有效支持;并以提高概念设计与后续设计阶段的产品信息共享与重用为目的,构建基于本体的概念设计产品信息模型。最后以机械手的概念设计为例,验证基于本体的概念设计产品信息模型的有效性。     

基于知识规则与几何推理的非单调装配序列规划方法

针对传统装配序列规划不考虑非单调因素的问题,提出一种基于知识规则与几何推理的非单调装配序列规划方法。首先,对非单调装配过程及其特点进行了分析,并采用包含状态信息的层次关联图及装配知识规则两种方式对非单调装配过程信息进行表达。最后依据所建立的装配信息模型,采用基于知识规则与几何推理相结合的非单调装配序列生成方法,实现非单调装配序列的规划。     

基于三维模型的装配工艺规划技术研究

对三维装配工艺规划关键技术和解决方案进行了研究,包括：层次模型和关系模型相结合的产品装配信息建模、基于仿真拆卸的装配工艺规划及装配工艺文件自动生成等问题,并基于CATIA平台开发出装配工艺规划原型系统,实现了交互式装配序列、路径规划,生成了装配工艺文件,验证了技术的可行性。     

基于装配的产品信息模型研究

本文提出了一种基于装配信息的产品概念设计建模方法。该模型采用了面向对象技术,将概念设计中的物理元素及其它实体用对象表达,通过对象间关系的建立来描述产品的装配信息。为了适应设计过程中频繁修改装配模型。用基本类构成装配模型的特点,用散列表生成结点的索引项,并利用实例推理技术,实现实例对象的快速查询。     

基于功能和装配关系的装配单元规划北大核心

装配单元规划是在一定的产品功能和装配关系下,将产品划分为若干个零部件的集合。首先分解产品功能,构建功能单元模型,然后将产品零部件分为功能件和连接件,基于功能件间装配关系信息,构建装配语义信息表和装配关系模型。选定装配基础件,综合功能单元模型和装配语义模型,通过模糊聚类完成装配单元划分。     

支持产品工程分析的集成产品模型

本文分析了基于产品几何模型、装配信息，支持产品工程分析的集成产品模型描述。该模型在产品几何模型和装配模型的基础上集成了零部件设计参数、参数之间的约束关系、受力状况、力学性能。阐述了Pro/Engineer平台应用系统原理。     

基于Web的卧式柱塞泵虚拟装配系统的研究

基于网络的虚拟装配为传统装配技术提供了新的思路。文章提出了虚拟装配仿磁心定位概念，应用虚拟现实建模语言（VRML）和动态服务器页面（ASP）技术，从产品的拆卸／装配分析角度出发，以卧式柱塞泵为例实现了网络环境下虚拟装配系统的动态仿真，装配信息实时反馈以及虚拟环境下对数据库的快速查询方法，并研究了实时动画和交互的关键技术，     

Assembly support using AR technology based on automatic sequence generation

This paper addresses the challenge of integrating simulation and augmented reality tools into final assembly operations. The study presented, comprises an assembly sequence generation algorithm, for the creation of assembly sequences and steps, carried out by engineers with the use of CAD data and any additional input concerning the product. This information is then delivered to the AR (Augmented Reality) module, which is responsible for the visual instructions of the assembly task. The AR module is based on an algorithm that creates the virtual instructions, having as basis the assembly sequence of the specific product. The instructions are stored in the form of a template.     

Co-Evolution of Product Families and Assembly Systems

To cope with the intense global competition that is characterized by high product variety and short life cycles, manufacturers need to share manufacturing systems across products and product generations. Co-evolution of product families and assembly systems is proposed as a novel methodology for the joint design and reconfiguration of product families and assembly systems over several product generations. The co-evolution methodology capitalizes on the opportunities for design and assembly system reuse that are offered by modular product architectures and reconfigurable assembly systems. As a result, co-evolution can lead to reduced product development costs and increased responsiveness to market changes.     

Product analysis automation for digital MRO based on intelligent 3D data acquisition

3D data acquisition technologies are increasingly used in the area of maintenance, repair and overhaul (MRO) of long-life technical systems and industrial plants. Application fields are measuring, reengineering and reproduction of disassembled parts. Fraunhofer IPK is developing a reverse engineering process for provision of 3D product models based on 3D scans of complete assemblies to save disassembly time and to support change management and reengineering tasks. This paper depicts results of IPK's data processing approaches for automated separation and identification of single parts in 3D assembly scans as well as for mapping of assembly structures in product data management systems.     

Determination of extended availability and productivity for assembly systems using existing data base

Reliable information about the operational availability of assembly or production systems is of great importance for the users of complex production facilities, especially when such facilities operate at their capacity limit. Nowadays, in most cases, the availability of assembly systems is monitored and evaluated using collected status data. This paper presents a new approach for permanent productivity determination of assembly systems based on the usage of in-process acquired product data. This approach is especially applicable for manufacturing systems that produce goods for which complete product traceability is required.     

Integration of Product Design and Assembly Planning in the Digital Factory

As assembly process planning fulfils the main function of connecting product design to production simulation and thus, the production system itself, a feasible software solution is needed to support this process. Thus, a novel concept is presented that aims at improving the integration of digital product design and assembly planning by introducing a consistent data structuring. This approach helps to reduce redundant tasks and supports the continuous data exchange. It is based on the use of assembly features, i.e. pre-defined geometry elements that contain additional technological information.The prototypical implementation of the concept focuses on the use of commercially available software tools, expanding them with additional functionality for the application of assembly features. The feature-based concept has been tested with a scenario from the automotive supplier industry. For the considered assembly, a comparison between the conventional and the feature-based planning approach is presented in the paper. It points out that the major advantages of the developed concept can be seen in an improved data consistency as well as a higher level of efficiency within the planning activities.     

Open-architecture products

This paper defines open-architecture products (OAPs), a new class of products comprising a fixed platform and modules that can be added and swapped. Customers can adapt OAPs to their needs by integrating modules into the platform. Manufacturers will produce these platforms, while new small companies and customers will develop the modules, thus increasing employment and causing the economy to flourish. At the same time OAPs will provide consumers with the product they desire. Challenges include developing new OAP design software for non-professional designers and new assembly systems to facilitate economical assembly of a large number of product variants.     

Consensus tree method for generating master assembly sequence

An assembly process plan for a given product provides the sequence of assembly operations, their times as well as the required tools and fixtures for each operation. Much research has been done on automating and optimizing assembly sequence generation as the most important part of an assembly process plan. A novel method for generating the assembly sequence of a given product based on available assembly sequence data of similar products is presented. The proposed method uses a binary tree form to represent the assembly sequences of an existing family of products. A Genetic Algorithm is employed to find the consensus tree that represents the set of all assembly sequence trees with minimum total dissimilarity distance. This is similar to defining Generic Bill-of-Material. The generated consensus tree serves as a master assembly sequence for the product family. The assembly sequence for a new product variant that falls within, or significantly overlaps with, the scope of the considered family of products can be directly extracted from the derived master assembly sequence tree. The developed method is demonstrated using a family of three control valves. This novel method greatly simplifies and enhances automatic assembly sequence generation and minimizes subsequent modifications, hence, reduces assembly planning cost and improves productivity.     

Assembly system design and operations for product variety

Assembly is the capstone process for product realization where component parts and subassemblies are integrated together to form the final products. As product variety increases due to the shift from mass production to mass customization, assembly systems must be designed and operated to handle such high variety. In this paper we first review the state of the art research in the areas of assembly system design, planning and operations in the presence of product variety. Methods for assembly representation, sequence generation and assembly line balancing are reviewed and summarized. Operational complexity and the role of human operators in assembly systems are then discussed in the context of product variety. Challenges in disassembly and remanufacturing in the presence of high variety are presented. We then conjecture a future manufacturing paradigm of personalized products and production and discuss the assembly challenge for such a paradigm. Opportunities for assembly system research are summarized at the end of the paper.     

支持自顶向下设计的产品装配模型研究

产品的设计过程是一种自顶向下的设计过程,而产品装配模型是实现Top-Down设计的关键.论文在基于装配语义的装配特征的基础上提出了支持top-down设计的产品装配模型,讨论了模型的结构和采用多细节层次模型法建立产品装配模型的实现方法,提出了采用基于装配和加工特征统一的建模方法建立包含装配语义关系的零件模型,并在Pro/E软件平台上,开发了原型设计系统.