再制造工艺过程二阶优化决策方法

为形式化描述再制造工艺过程优化决策目标属性,从制造系统工程的角度建立了一种决策问题框架模型;为克服决策过程中存在的不确定性和信息不完整性,提出了一种基于专家评判及模糊回归理论的二阶段再制造工艺过程优化决策方法。其中决策方法第一阶段为工艺控制参量分析、专家方案制订、方案满意度评价阶段;第二阶段以控制参量值及满意度评价值为输入,进行模糊回归分析及优化决策计算,得出工艺控制参量方案的理论最优值及其决策目标满意度值。最后,通过某废旧机床导轨再制造工艺方案的决策案例,对该方法的具体应用和计算过程进行了验证说明。     

A robot fuzzy motion planning approach in unknown environments

A fuzzy robot motion planning approach is proposed in unknown environments for three-degree industrial robots. The proposed planning system is composed of several separate fuzzy units, which control individually each manipulator joint. Each unit combines a repelling influence, which is related to the nearby obstacle, with the attracting influence produced by the final manipulator configuration, to generate actuating command for each link. Effectiveness of the proposed approach is verified through simulation. __________ Translated from Journal of Harbin Institute of Technology, 2005, 37(10) (in Chinese)     

基于GERT图的废旧零部件不确定性再制造工艺路线模型

针对再制造系统工艺路线不确定性问题,建立一种基于图形评审技术的再制造工艺路线模型。首先对再制造工艺路线的不确定性进行分析,对参数进行描述,阐述四种典型再制造工艺路线,然后建立基于图形评审技术的某废旧零部件路线模型,该模型描绘了各废旧零部件的所有可能工艺路线;建立工艺的概率分支与各工序加工时间分布函数。通过信号流图和矩母函数对模型进行求解,得到废旧零部件到达某一节点的概率与期望时间。将该模型应用到废旧车床主轴再制造实践中,运用Arena仿真软件验证了结果的合理性。     

再制造/制造系统集成物流网络及信息网络研究

在再制造与制造集成系统中,传统的物流网络不再适用。为了解决该问题,研究了再制造／制造系统物流网络的结构,给出了其物流网络的混合整数规划模型,并通过案例进行了分析。该模型特点是：网络结构为闭环网络;正向物流中统筹考虑再生品和新产品的物流分配,再生品和新产品可以相互替代。同时,基于Internet／Intranet／Extranet技术,探讨了对再制造／制造系统物流网络的运行具有重要作用的信息系统的组成。     

Identification of uncertain nonlinear systems for robust fuzzy control

In this paper, we consider fuzzy identification of uncertain nonlinear systems in Takagi-Sugeno (T-S) form for the purpose of robust fuzzy control design. The uncertain nonlinear system is represented using a fuzzy function having constant matrices and time varying uncertain matrices that describe the nominal model and the uncertainty in the nonlinear system respectively. The suggested method is based on linear programming approach and it comprises the identification of the nominal model and the bounds of the uncertain matrices and then expressing the uncertain matrices into uncertain norm bounded matrices accompanied by constant matrices. It has been observed that our method yields less conservative results than the other existing method proposed by S?krjanc et al. (2005) [11] and [12]. With the obtained fuzzy model, we showed the robust stability condition which provides a basis for different robust fuzzy control design. Finally, different simulation examples are presented for identification and control of uncertain nonlinear systems to illustrate the utility of our proposed identification method for robust fuzzy control.     

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     

基于网络层次分析的企业再制造产品评估模型

分析了企业面临再制造产品选择的复杂决策问题,通过改进层次分析法建立了基于依存和反馈的网络层次分析评估模型,对存在多个评价标准、控制维度、评价因素的再制造产品选择进行了综合评估。通过实例构造系统超矩阵,运用SD软件求关联超矩阵的收敛状态,得到稳定的极限超矩阵,计算出备选项权重,解决了再制造的产品选择问题。     

制造/再制造集成物流网络模糊优化设计方法

为提高制造/再制造物流管理绩效,提出了合理设计制造/再制造闭环物流网络结构.将废旧产品回收量、新产品或再生品需求量、物流设施的生产或处理能力等看成三角或容差模糊参数,建立了单周期、单回收产品、有能力限制、同一物流设施备选地点对应多种可选物流设施类型的集成物流网络设计的模糊混合整数线性规划模型.为求解该模型,利用模糊机会约束规划方法将其转换成等价清晰模型.介绍了模糊混合整数线性规划模型针对同类型不同规模的物流设施选择的扩展应用,阐述了置信水平重要程度的分析方法,通过算例验证了模糊优化设计方法的有效性.     

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.     

不确定需求和能力约束下的多目标多工厂生产计划

针对多个具有供需关系的制造工厂和多个地域分散的客户组成的供需网络,研究了不确定需求、生产能力和运输能力条件下的多周期多目标生产计划方法,决策变量为每个周期上工厂的生产计划及工厂间的运输计划,优化目标为最大化总利润与最大化任意客户的平均客户满意度.利用模糊数描述不确定参数,在建立问题的混合整数规划模型后,将此模糊数学模型转化为最大化满意度的加权和模型,并提出了禁忌搜索与后向启发式方法相融合的B-TS算法.计算实例证明,B-TS算法能够有效获得多目标多工厂生产计划.     

A hybrid approach for set-up planning

In this paper, various constraints on set-up planning are identified and discussed. Rules and heuristics are created based on these constraints to determine the bilateral precedence relationships between the machining process of features and tool approach directions. By looking at the problem caused by the conflict between the feature precedence relationships and set-up precedence relationships, an optimisation approach is developed to find the optimal plan(s) from all the feasible set-up candidates. The criterion used is the minimum number of set-ups. As a result, alternative set-up plans are generated with a certain number of set-ups required. This research is limited to machining prismatic components only.     

随机和模糊约束下的扩展型集约生产计划方法

针对不确定环境下具有模糊需求量、随机加工能力约束的多阶段多品种集约生产计划问题进行了研究。在考虑生产任务跨阶段性的基础上,建立扩展型随机模糊混合优化模型,并运用随机模糊机会约束规划理论、不确定等价方法和Lingo软件对模型进行转化和求解。通过案例分析,证明了该模型和方法的有效性,为决策者在不确定环境下的生产计划决策提供了依据。     

Determining dimensions for process planning: A backward derivation approach

Computer-aided process planning has shown its great importance in computer integrated manufacturing systems. Dimensioning and tolerancing plays a key role in process planning since the final workpiece must ensure conformance with the dimensions in its blueprint. This paper proposes a simple, efficient approach to derive working dimensions for process planning, based on the tolerance chart technique. The paper first reviews briefly some approaches previously presented, such as the mathematical linear equation approach and the graph tracing approach, it then proposes the backward derivation approach. By setting up the origin of a coordinate system at the left-most surface in a blueprint (B/P), the approach first determines the distances from all the B/P surfaces to the origin by use of the B/P dimensions. Then by updating these dimensions, the final working dimensions are calculated backwards by a simple arithmetical equation.     

A tool planning approach considering cycle time constraints and demand uncertainty

The tool planning problem is to determine how many tools should be allocated to each tool group to meet some objectives. Recent studies aim to solve the problem for the cases of uncertain demand. Yet, most of them do not involve cycle time constraints. Cycle time, a key performance index in particular in semiconductor foundry, should not be ignored. The uncertain demand is modeled as a collection of scenarios. Each scenario, with an occurrence probability, represents the aggregate demand volume under a given product mix ratio. A genetic algorithm embedded with a queuing analysis is developed to solve the problem. Experiments indicate that the proposed solution outperforms that obtained by considering only a particular scenario.     

基于模型定义的工艺信息建模及应用

为实现基于模型定义技术在工艺设计中的应用,考虑零件制造的中间状态,以工序MBD模型为基本单位,通过加工特征将几何信息与工艺信息相结合,建立了面向工艺的MBD模型。然后以工序模型为载体,建立MBD的零件工艺信息模型。采用多视图方法,分别将三维标注信息按照专业类型和工艺规划过程进行划分和管理,并将工序模型进一步划分为实体层、扩展层和应用层。以一个工艺信息实例说明了基于模型定义的工艺信息建模在三维工艺规划系统中的应用。     

Algorithms for computer-aided generative process planning

Process planning is the function within a manufacturing facility that establishes the machining processes and parameters to be used so as to convert a piece-part from its initial form to the final form predetermined on an engineering drawing. Computer-aided process planning (CAPP) has become a major focus of manufacturing automation as it forms the interface between computer-aided design (CAD) and computer-aided manufacturing (CAM). Issues in CAPP include part representation, process selection, alternative process-plan generation, intermediate surface and tolerance determination, and operation sequencing. This paper focuses on quantitative models for determining cutting dimensions and tolerances for intermediate surfaces, and on a heuristic for sequencing cutting operations.     

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.     

模拟退火粒子群优化算法在工艺规划决策中的应用

为了实现面向精益生产的制造系统中的工艺与调度并行设计,在工艺规划决策中,建立了面向精益生产的工艺规划与调度集成模型.在考虑设备负载平衡以及完成加工任务时间最短的条件下,设计了一种离散模拟退火粒子群优化(Particle Swarm Optimization based on Simulated Annealing,SAPSO)算法,并行设计及优化零件的工艺方案和调度方案,并最终获得其最优工艺方案及与之相对应的优化调度方案.通过对10台设备10种零件的示例仿真验证了算法的有效性.     

An agent-based collaborative assembly process planning system

In recent years, the competition among manufacturers to reduce the development time of new products has been quite fierce. At the same time, customers’ needs have become relatively diverse. Considering these facts, it is essential for manufacturers to build an assembly line in the shortest time possible. Because an assembly line for varied and complex products involves numerous workstations, assembly operations and resources, it is extremely difficult for assembly process planners to develop an efficient assembly sequence and position. Thus, in order to overcome such complications, the best alternative is for a number of process planners to develop a process plan synchronously . This paper introduces a new process planning method for assembly lines based on a collaborative system. In it we propose an agent-based collaborative process planning system, and to verify it, we implement the system in an Internet environment and apply it to some practical case studies.     

A geometrical approach to computer-aided process planning for computer-controlled machine tools

This paper documents part of a research program which has been under way at the CIM Centre at Swinburne University of Technology since 1989. The purpose of the research program was to develop an open-architecture machine tool control system and then to see how that system could be used to change the distribution of traditional manufacturing design, planning and control functions. This paper examines one part of that research program and focuses on a methodology which could prove to be useful in the machine tool selection, cutter selection and cutter path generation phases of process planning for cutting operations on workpieces in computer-controlled machine tools.It is suggested that a configuration space transform be used for each cutter/machine tool combination to find the volume that the combination could remove from the uncut workpiece without removing any of the material that will form the final workpiece. A method of comparing these volumes from different combinations is then outlined. The output of this method is a reasonable sequence of machine tools and cutters. Path planning can then be carried out for each of the chosen combinations using a method similar to the one used to find the possible volume to be removed.Possible implementation techniques, and their limitations on existing computer hardware, are discussed and the most promising of these are identified, based upon some properties of configuration space transforms.