快速重组制造系统中的组态原理及其实现

在研究组态原理及其核心内容的基础上,提出了在快速重组制造系统（ＲＲＭＳ）中实现组态原理的方法,并详细讨论了其适应性,组态原理在北京机研究所的柔性制造系统ＪＣＳ－ＦＭＳ－１上得到了部分应用,证明利用组态原理建立的柔性制造具有较广的适应性和快速可调整的能力。     

数据赋能离散式制造的特定工件的质量符合率预测北大核心

物联网和5G技术的发展使得生产制造环节中产生的大量数据被收集变成可能。中国智能制造的创新和发展离不开数据驱动,基于数据驱动的离散式生产制造中特定工件的质量符合率,对制造企业的生产制造过程控制极为重要,是实现智能生产和智能决策的关键环节。通过对国内外关于质量符合率的研究进行文献综述,界定离散式制造、特定工件和质量符合率的概念,基于实际生产特定工件中收集的12 934笔数据建立质量符合率随机森林模型和Bagging模型,分别对包含20个变量的数据集进行学习。根据两个模型预测精度的对比分析,表明随机森林模型对质量符合率的预测更加有效,其预测精度达99.47%。此外,基于数据样本集,对影响特定工件质量水平的变量进行重要性分析,找出关键变量,提取不同质量水平的特定工件的重要特征,为提高特定工件质量符合率提供决策依据和指导。     

基于多功能机器与多能工的动态单元制造系统模型

为了成功地实施动态单元制造系统,同时考虑技术性问题（包括生产单元构建和设计、生产单元之间与生产单元内部的物料移动等）和人员问题（包括员工工资、员工雇佣和解雇等）,综合研究和分析了多功能机器和多操作技能员工的动态单元制造系统的生产单元构建、生产单元之间与生产单元内部物料移动、库存和延迟生产、员工分配和柔性生产路径,创新性地提出一个整合的混合整数规划模型。通过遗传算法对数值试验求解,结果验证了新模型的可行性和有效性。     

FMC的成组生产作业计划仿真与作业控制系统

本文介绍的是柔性制造单元(FMC)的生产作业计划仿真与作业控制系统。在这个系统中,生产作业计划及其仿真、生产控制和作业统计集为一体。该系统软件SSPCS已被用于柔性制造单元“S3—FMC—01”。该柔性制造单元是一个用于加工回转体零件的自动化加工系统。实际上,该系统软件可以被看作一个用于柔性制造单元的袖珍式生产管理信息系统。文中介绍了作业计划仿真的目标评价函数及其仿真原理,柔性制造单元具有反馈机制的生产控制模式,并论述了生产过程中的计划滚动、进度管理与作业统计、生产过程中的故障处理措施分析等问题。     

机械制造企业的成组技术改造

我国多品种小批量机械制造企业实施成组技术改造,既要立足于现实国情又要面向先进制造技术的应用。本文探讨了我国多品种少批量机械制造企业成组技术改造的技术规划问题,建立了企业模型,论述了成组单元建设、单元的柔性问题的解决方案、企业管理和计算机技术的应用等方面的问题,指出数控和建立虚拟成组单元是解决柔性问题的有效办法。     

采用基于拟阵的贪婪算法优化RRMS的布局

研究探索了快速可重组制造系统布局规划中的优化设计问题，建立了基于拟阵的数学规划模型，通过对比选取贪馋算示作为优化算法，并编制开发了此算法的应用程度，针对某工厂的重组实践，经与现场结查对比证明，在快速重组制造系统的布局规划优化设计中，基于拟阵的贪馋算法是一种快捷实用的算法。     

刍议汽车制造中柔性生产线的应用

随着我国汽车制造行业的快速发展,柔性生产线在汽车制造中得到了广泛应用,并且效果非常显著,柔性生产线涵盖了汽车生产的多个环节,在某种程度上提高汽车的生产效率。本文简要概述了柔性生产线的主要内容,分析了其在汽车生产中具体的实施步骤,最后探讨了柔性生产线未来发展趋势。     

GRMS——一种新的面向订单的制造系统模式

本文提出了一种新的面向订单的制造系统模式－广义随机制造系统模式－ＧＲＭＳＭ。ＧＲＭＳ采用协调分布式控制方式，通过自治单元自下而上的竞争、自上而下的协调改善系统的性能；采用基于工作地的自主式工艺设计和资源重用等策略，实现订单制造的优化目标；采用基于动态网筛的漏斗模型，实现面向订单的均衡生产。文章介绍了ＧＲＭＳ的基本原理、体系结构，运行机制和特点。     

基于快速重组制造系统的CAPP技术探讨

适用于快速重组制造系统中的ＣＡＰＰ技术是快速重组制造系统的重要技术基础，分析了此种技术与传统ＣＡＰＰ技术的区别，并在此基础上重点对其关键技术进行了探讨。     

基于OPC的柔性制造单元控制信息系统设计与实现

柔性制造单元的控制信息系统是整个柔性制造单元的核心,为使得该系统具有很好的开放性、柔性、和集成性,本文设计了基于OPC的柔性制造单元控制信息系统,最后对OPC服务器程序的开发做了具体介绍。     

基于公理设计的可重构制造系统设计

可重构制造系统是面向客户定制的一种新的制造模式.先阐述了可重构制造系统的概念及其特点,并对目前关于可重构制造系统的设计研究进行了总结.然后,以快速响应市场变化为目标,提出了基于公理设计理论的设计方法及设计步骤,对可重构制造系统进行设计,降低了设计的复杂性.层次化设计和分解方法保证了在设计过程中以适当的顺序做出合理决策.最后给出了可重构制造系统的工作流程图.     

Reconfigurability consideration and scheduling of products in a manufacturing industry

Reconfigurable manufacturing system is a new type of manufacturing system which can change its capacity and functionality very easily and quickly whenever required. RMS (reconfigurable manufacturing system) has capacity and functionality exactly what is required. RMS is adjustable to the fluctuating demands and it can be easily upgraded with new process technology. Reconfigurability of a manufacturing system is measured in terms of cost, effort and time. It is the ability of a manufacturing system to be reconfigured quickly with low reconfiguration effort at low cost. In the present work, reconfigurability has been considered in Continental Automotive Components Pvt. Ltd. on the basis of RMS principles. A modified reconfigurable layout has been proposed for an assembly line and scheduling of the products has been done for the criteria reconfiguration effort, profit over cost and due date. Scheduling of the products has been done using the integrated approach of Shannon entropy and RIM (Reference Ideal Method). R program has been written for scheduling. Sensitivity analysis has been conducted for the problem.     

Evaluation of the logistic model of the reconfigurable manufacturing system based on generalised stochastic Petri nets

To reveal the influence on system performance by the logistic model of reconfigurable manufacturing system (RMS), the generalised stochastic Petri nets (GSPN) modular modelling approach is presented in this paper. It is based upon the characteristics of a bottleneck service. According to this approach, the bottleneck service in the production process is found first. By corresponding different resources in the service to different modules of the GSPN, the module is reconfigured. The analysis of the model using the Markov chain is hereby presented, as is the average utilisation factor of RMS. Following this, the production capacity of different products and the average productivity of reconfigurable manufacturing cells (RMCs) are discussed.     

Cell design and multi-period machine loading in cellular reconfigurable manufacturing systems with alternative routing

This paper deals with the design and loading of Cellular Reconfigurable Manufacturing Systems in the presence of alternative routing and multiple time periods. These systems consist of multiple reconfigurable machining cells, each of which has Reconfigurable Machine Tools and Computer Numerical Control (CNC) machines. Each reconfigurable machine has a library of feasible auxiliary machine modules for achieving particular operational capabilities, while each CNC machine has an automatic tool changer and a tool magazine of a limited capacity. The proposed approach consists of two phases: the machine cell design phase which involves the grouping of machines into machine cells, and the cell loading phase that determines the routing mix and the tool and module allocation. In this paper, the cell design problem is modelled as an Integer Linear Programming formulation, considering the multiple process plans of each part type as if they were separate part types. Once the manufacturing cells are formed, a Mixed Integer Linear Programming model is developed for the cell loading problem, considering multi-period demands for the part types, and minimising transportation and holding costs while keeping the machine and cell utilisations in each period, and the system utilisation across periods, approximately balanced. An illustrative problem and experimental results are presented.     

Multi-objective multi-unit process plan generation in a reconfigurable manufacturing environment: a comparative study of three hybrid metaheuristics

Low costs, high reactivity and high quality products are necessary criteria for industries to achieve competitiveness in nowadays market. In this context, reconfigurable manufacturing systems (RMSs) have emerged to fulfil these requirements. RMS is one of the latest manufacturing paradigms, where machines components, software or material handling units can be added, removed, modified or interchanged as needed and when imposed by the necessity to react and respond rapidly and cost-effectively to changing. This research work addresses the multi-objective single-product multi-unit process plan generation problem in a reconfigurable manufacturing environment where three hybrid heuristics are proposed and compared namely: repetitive single-unit process plan heuristic (RSUPP), iterated local search on single-unit process plans heuristic (LSSUPP) and archive-based iterated local search heuristic (ABILS). Single-unit process plans are generated using the adapted non-dominated sorting genetic algorithm (NSGA-II). Moreover, in addition to the minimisation of the classical total production cost and the total completion time, the minimisation of the maximum machines exploitation time is considered as a novel optimisation criterion, in order to have high quality products. To illustrate the applicability of the three approaches, examples are presented and the obtained numerical results are analysed.     

Operator allocation planning for reconfigurable production line in one-of-a-kind production

In a one-of-a-kind production (OKP) company, the operation routing and processing time of an order are usually different from the others due to high customisation. As a result, an OKP company needs to dynamically adjust the production resources to keep the production lines reconfigurable. Through a proper assignment of operators in different sections of a production line, bottlenecks and operator re-allocation during production can be reduced effectively. In this paper, a mathematical model is introduced for optimal operator allocation planning on a reconfigurable production line in OKP. The optimisation objectives are to minimise the total number of the operators, total job earliness and tardiness, and the average work-in-process storage. A branch-and-bound algorithm with efficient pruning strategies is developed to solve this problem. The proposed model and the algorithm are empirically validated by using the data of a windows and doors manufacturing company. A software system based on the proposed approach has been implemented in the company.     

A stochastic model of a reconfigurable manufacturing system Part 3: Optimal selection policy

Products required by customers are classified into several product families, each of which is a set of similar products. A reconfigurable manufacturing system (RMS) satisfies customer requirements by ensuring that each family corresponds to one configuration of the RMS. Products belonging to the same family will be produced by the RMS under the corresponding configuration. The manufacturing system is reconfigurable for different families. To utilize the RMS, a selection policy that is an action rule is needed, by which the manufacturer selects a family to produce ordered products belonging to the selected family. Thus, an important issue for an RMS is the optimal selection policy. Based on a stochastic model, an optimization problem stemmed from the issue is formulated. Two solution procedures are devised to solve the optimization problem. Numerical examples are presented for evaluating the efficiency of the algorithms.     

A methodology for design and reconfiguration of reconfigurable bending press machines (RBPMs)

Customer requirements have become very dynamic and unprecedented. A manufacturing paradigm called reconfigurable manufacturing system was initiated to adjust the physical machine entities. The main enabler of a machine structure’s reconfigurability is a modular design approach. The paper explains a function-driven object-oriented methodology for the design and reconfiguration of RBPMs. The complete method aims to optimise initial design of RBPMs, followed by subsequent design of RPBM modules which are stored in a module library so as to enable full-automatic reconfiguration of the RBPMs. The methodology is implemented on a pilot project to design a 145 ton bending capacity RBPM, with a maximum reconfigured length of 5?m and total height of 3?m. In order to deduce the design for the reconfigurable bending press machine, the reconfigurability needs were identified first, followed by the construction of a function tree for the machine. The function tree identifies the primary function for the RBPM, which is to bend sheet metal. The primary function is further decomposed to lower level functions until terminal functions are arrived at. The terminal functions are then used to identify the modules for the machine. The modules implement specific brunches of the machine functions.     

Multi-objective sustainable process plan generation in a reconfigurable manufacturing environment: exact and adapted evolutionary approaches

Achieving competitiveness in nowadays manufacturing market goes through being cost and time-efficient as well as environmentally harmless. Reconfigurable manufacturing system (RMS) is a paradigm that is able to meet these challenges due to its scalability and integrability. In this paper, we aim to solve the multi-objective sustainable process plan generation problem in a reconfigurable environment. In addition to the total production cost and the completion time, we use the amount of greenhouse gases (GHG) emitted during the manufacturing process as a sustainability criterion. We propose an iterative multi-objective integer linear programming (I-MOILP) approach and its comparison with adapted versions of the two well-known evolutionary algorithms, respectively, the Archived Multi-Objective Simulated Annealing (AMOSA) and the Non-dominated Sorting Genetic Algorithm (NSGA-II). Moreover, we study the influence of the probabilities of genetic operators on the convergence of the adapted NSGA-II. To illustrate the applicability of the three approaches, an example is presented and obtained numerical results analysed.     

Reconfiguration: a key to handle exceptions and performance deteriorations in manufacturing operations

During a manufacturing operation, exceptions may occur dynamically and unpredictably. Their occurrence may lead to the degradation of system performance or, in the worst case scenario may interrupt the production process by causing errors in the schedule plan. This paper classifies three families of exceptions: (1) out-of-order events such as machine breakdowns, (2) operational out-of-ordinary events such as rush orders and (3) deteriorations of manufacturing resource performance such as reductions of machines’ utilization. In all cases, in order to maintain an adequate level of system performance, it is necessary to detect exceptions, to diagnose them quickly and to recover them by taking corrective actions to avoid fault propagations. Decisions concerning how to deal with exceptions, i.e. which strategy to implement, depend on the manufacturing environment (dedicated line, flexible system, reconfigurable system or a mix of them) and the advantages arising from using a certain exception handling policy vary from one production system to another. The activity of reconfiguring manufacturing resources has been demonstrated to be a powerful operation strategy to handle machine breakdowns. This paper extends the concept of ‘reconfiguration for exception handling’ to other families of exceptions and proposes reconfiguration for their recovery. The reconfiguration process is handled by an agent-based control system that implements four negotiation processes among manufacturing resource agents.