Concurrent and collaborative process planning for automotive general assembly

To ensure competitiveness in today’s automotive market, process planning should be performed concurrently with other engineering activities during new car development. In this paper, new business workflows and the support system for process planning of an automotive general assembly are proposed and presented. Since process planning for a whole general assembly shop is a huge and complex job, several process planners should execute planning together. Therefore, planners should consult with one another regarding his/her results through continuous online communication and cooperation. Process planning based on computers, database and Internet is inevitable for reducing manufacturing preparation time and costs through concurrent and collaborative engineering. In this research, the Web-based process planning system for general assembly shops using the bound operation method is implemented and proven. By using this system, savings in time and cost of assembly process planning are possible, and the reliability of the planning results is greatly improved.     

装配工艺规划后处理的研究与应用

装配工艺规划是产品装配活动中的一个关键环节 ,直接影响着产品的质量和装配费用。计算机辅助装配工艺规划 (CAAPP ,ComputerAidedAssemblyProcessPlanning)在一定程度上提高了装配工艺规划的效率 ,然而它并不能完成装配工艺规划中的所有活动。装配工艺规划后处理是装配工艺规划的重要组成部分 ,它作为CAAPP的有效补充 ,利用计算机辅助手段进一步提高了装配工艺规划的自动化水平。本文提出了装配工艺规划后处理的体系结构 ,并从装配信息建模、装配工艺文件的生成和装配资源共享与信息转换三个方面对其关键技术进行了较为系统的研究     

Agent technology for collaborative process planning: a review

Agent technology has been considered as a promising approach for developing process planning systems and optimizing process plans in a distributed environment. A number of researchers have attempted to use agent technology in process planning for the purpose of integrating systems, tools and algorithms which are geographically distributed. In this paper, the historical background of agent technology is systematically reviewed. A comprehensive review of agent technology and its applications in manufacturing is presented including the applications of agent in scheduling, control, and enterprise integration and supply chain management. The focus of the paper is on how agent technology can be further developed in the support of collaborative process planning as well as its future research issues and directions in process planning. The current research directions in computer aided process planning (CAPP) and issues in traditional CAPP approaches are also discussed. Three agent-based approaches for process planning are presented. Finally, the key issues in developing agent-based collaborative process planning systems are summarized.     

面向装配工艺规划与仿真的装配工具信息模型的研究

详细论述了装配工具信息模型建立的方法,研究了建立装配工具信息模型的相应策略,并以Pro/E为平台建立了相应的装配工具库系统并给出了搜索工具的算法流程.     

计算机辅助飞机装配协调工艺设计系统研究

为了解决飞机装配协调工艺手工编制所存在的工作量大,效率低等问题,本文提出了计算机辅助飞机装配协调工艺设计系统,分析了装配协调工艺设计的流程,采用基于规则的推理技术进行标准工艺装备的选择,并通过建立工装协调关系模型和绘图算法完成互换协调图表的自动绘制。     

Web环境下基于知识的协同式CAPP系统

简介了一个Web环境下基于知识的协同式计算机辅助工艺设计系统。包括：系统结构、主要功能模块和信息流程、工艺知识表达及函数的功能、采用递归算法的推理机制、协同工艺设计机制和一个应甩实例。该系统利用java语言编程。可以生成满足企业生产要求的工艺过程文件。     

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.     

基于I-DEAS平台的产品装配仿真系统的开发

对于尚处在设计阶段的产品来说,可装配性好坏最直观的效果是在计算机上仿真产品的实际装配过程。为此提出并实现了一种基于I-DEAS平台的装配仿真系统,该系统可有效地对产品的可装配性进行评价,并验证装配工艺规划结果,并在此基础上生动直观地进行产品的预装配,以检测与装配有关的问题而无需实物模型。     

一种基于遗传算法的装配序列优化方法

基于遗传算法建立了装配序列生成模型,对装配序列进行优化生成。为提高优化效率,该算法将装配方向作为已知数据给出,并引入子装配体进行分层规划。最后,以蜗轮减速器装拆序列规划为实例验证该方法的有效性。     

Decentralised production-distribution planning system using collaborative agents in supply chain network

With the fast development of information technology and the global market, collaboration between different functional units in a supply chain becomes one of the most critical factors for global companies to respond to rapid changes in customer needs and increase the efficiency of the whole supply chain. This supply chain environment requires a production-distribution planning system to enable the collaboration between production and distribution units more quickly and orderly. Generally, collaboration in a supply chain needs to resolve conflicts between two decentralised functional units, because each unit tries to locally minimise its own costs, not the overall supply chain costs. Also, there exists incomplete information sharing according to the information privacy of each functional unit. This paper proposes a decentralised production-distribution planning system using collaborative agents that can efficiently mediate the planning gaps between two decentralised planning functions: production and distribution. The validity of collaborative-agent model has been shown using some lemmas and numerical examples.     

基于零件约束的装配规划技术研究

装配规划是虚拟装配中的关键技术。这里将装配序列的分层规划方法和拆卸法求解装配序列的方法相结合，在研究产品装配层次结构的基础上，以子装配体为研究对象，利用零件之间的装配约束信息求解零件的拆卸方向和顺序，进而实现产品的装配顺序和路径规划。     

Integrated knowledge-based assembly sequence planning

This paper presents a novel approach and system for the automatic generation, selection and evaluation, optimisation, and simulation of assembly plans. The information and knowledge about a product and its assembly (e.g. assembly constraints, solid model and CAD database, heuristic rules) are described using a hybrid approach and model with numeric and symbolic representation. A new methodology is presented to generate all feasible assembly sequences of the product by reasoning and decomposing the feasible subassemblies, and representing them by the assembly Petri net modelling. Qualitative strategic constraints are then used to evaluate the feasible assembly sequences. In order to obtain a good assembly sequence, some quantitative criteria such as assembly time and cost, workstation number, operator number, and part priority index are applied to select the optimal assembly sequence. Based on DFA analysis, MTM time analysis, and assemblability analysis, estimates are made of the assembly time and cost of the product when each of these sequences is used. A knowledge-based system KAPSS has been developed to achieve the integration of generation, selection evaluation, and visualisation of the assembly sequences.     

汽车总装配工艺的快速自动规划研究

为实现汽车装配工艺的快速规划,提出将汽车装配工艺规划的区域层次法与任务分配的最大集算法相接合的方法。首先,对汽车零部件装配关系进行分析,并据此进行整车区域层次建模,形成“零部件∈层次∈区域∈整车”的树状结构,在此基础上对零部件进行检索,生成装配任务,确定各任务之间的优先关系;然后运用最大集算法确定各区域内装配任务的先后顺序,将各任务分配到区域子工位;最后,结合生产线实际资源约束情况,对各区域子工位之间的作业顺序进行调整,从而完成规划。应用这种规划方法,开发了一套面向汽车总装的计算机辅助i艺规划系统,实现了装配任务的快速自动规划。     

面向工艺设计的制造过程建模

基于工艺设计对产品制造成本、质量和效率的重要影响,提出了一种基于工艺设计的制造过程建模方法,以通过对过程模型的仿真,预测、分析和优化工艺设计效果。基于对制造过程的特征分析,采用面向对象的方法,首先将制造过程定义为一组成对象,并划分为制造活动、过程控制和制造资源3类成分对象,建立了制造过程类结构模型和动态过程模型。分别定义了工序类、制造资源类和过程控制类的类结构模型,以及各类对象的方法和属性。基于这些模型开发了一种计算机辅助工艺设计系统,可快速、自动地构建工艺设计定义的制造过程模型,并对过程参数（成本、时间）、切削加工、工件物流进行计算和仿真。     

Distributed planning of collaborative production

Collaborative production is viewed in two related dimensions: collaboration among machines to achieve increased reliability, quality and productivity; and collaboration between machines and human supervisors to combine internal and global control information. A structure, combining centralised planning and human-machine integration, is developed for distributed planning of such collaborative production. The centralised planning relies on game-theoretic optimisation techniques supported by knowledge-based rules for coalition formation of cooperating production operations. The product of the centralised planner is a general, common production plan. The feasibility of this model is demonstrated mathematically. If the centralised planner cannot reach a solution, then human input is sought. For integrating the human and machine knowledge to reach effective solutions, a neural network model is demonstrated. A simulation demonstrates that the distributed human and machine inputs can be combined under this framework. Such a distributed planning structure can overcome the major difficulties encountered in computerised production systems that seek full automation.     

可靠性驱动的装配工艺方案研究

为了提高产品整机可靠性,将可靠性控制措施引入到装配工艺方案中.由于产品的可靠性主要体现在功能失效上,因此利用结构分析和设计技术(Structured Analysis and Design Technique,SADT)对产品进行功能分析并建立完善的SADT模型,然后采用失效模式与影响分析(Failure Modes and Effects Analysis,FMEA)方法对“元动作”和相应功能需求进行故障分析得到可能的故障模式和故障原因,针对故障原因分析可靠性控制措施,最后,将该分析方法应用到某加工中心分度工作台的装配工艺方案制定的过程中.结果表明,可靠性驱动的装配工艺方案较传统的装配工艺方案具有更强的逻辑性和目的性,对于提高产品可靠性具有重要作用.     

面向生产现场的虚拟装配工艺规划技术

针对生产现场的需求和虚拟装配技术的发展,阐述了虚拟装配技术在装配工艺规划、装配精度预分析、管路与线缆装配及装配现场管理等方面的应用和发展.提出了半沉浸式虚拟装配工艺规划系统的整体思路及实现方法;虚拟环境下的线缆和管路的离散控制点建模及动态布局技术;虚拟环境下的带公差的产品建模方法和装配精度预分析技术.指出虚拟装配工艺规划技术能充分利用人的经验和感知,通过模拟真实装配过程,不仅可实现产品的装配顺序和路径规划,而且也是提高装配精度和装配可靠性问题的有效手段,为提高装配现场现代化管理水平提供了有效途径.     

水平井牵引机器人虚拟装配规划研究

快捷的装配工艺是水平井牵引机器人使用与维护的有力保障.结合机器人的结构特点,研究装配顺序与装配路径规划方法,并针对自主研制的水平井牵引机器人,开发虚拟装配规划系统,验证规划算法的有效性.     

Constraint ratio in product assembly planning

Assembly planning considers the product, process, and production system. The existence of constraints makes the assembly planning process difficult and time consuming. The planning degree of freedom (PDOF) for designers will be increased if the number of constraints is decreased on either the product or the other sides. A higher PDOF means that companies can be more flexible in responding rapidly to the assembly of parts. In this paper, a constraint ratio (C_R) has been defined to measure the influence of the product constraints on assembly planning. Some rules have been established to simplify the evaluation procedures of the constraint ratio of the product. Examples are illustrated and explained.     

面向协同装配规划的信息模型研究

为解决复杂产品的装配设计团队和装配规划团队间的协同工作,提出了装配结点概念,用以集成描述产品装配信息,利用装配结建立了产品的装配联系图模型,通过图模型中顶点和边的属性,分别独立描述零件和装配信息.给出了一个基于割顶点的装配联系图层次分解算法,构建了基于共享零件的产品结构层次树模型.基于结构层次树模型,描述了协同装配规划中的协同工作信息.利用实例说明了面向协同装配规划的信息建模过程及模型的有效性.