批量客户化生产模式下的模块划分方法研究

在批量客户化生产模式下,不仅要考虑客户对产品的多品种小批量的功能需求,又要满足客户对产品的大批量生产的低成本的要求,合理有效的模块划分是解决上述矛盾的关键。在模糊聚类分析及信息熵理论的基础上,提出了考虑客户需求、产品的装配、成本和维修等综合因素的模块划分方法和策略,分析了模块聚类的相关准则和基于信息熵的量化评价方法,建立了相应的数学评价模型,并以电钻为例,利用提出的方法得出了用模块化方法进行产品再设计时模块划分的初始方案。     

可重构制造系统布局规划方案的灰色模糊综合评价方法

针对可重构制造系统布局规划方案的决策问题，提出了面向可重构制造系统布局规划方案的灰色模糊综合评价方法。首先对影响制造系统性能的因素进行分析，建立层次化的综合评价指标体系；然后建立布局方案的仿真模型，利用商业仿真软件获取制造系统动态运行时的定量评价指标数据，并通过专家打分法对制造系统的定性评价指标进行量化，在此基础上，利用灰色关联分析法，确定评价指标的权重；最后采用模糊综合评价法，实现了布局规划方案的综合评价，提高了布局规划方案选择的决策水平。以某研究所机械加工车间为研究对象，验证了该方法的可行性和有效性。     

飞机总体外形设计中的模糊知识处理方法研究

飞机总体外形设计中存在着大量的模糊因素,讨论模糊知识的处理方法－ＣＦ方法,主观Ｂａｙｅｓ方法,隶属函数方法,模糊变换方法,ＦＰｅｔｒｉ网等。这些方法在飞机总体外形模糊设计专家系统中都得到应用。     

基于Web的智能CAPP系统的研究

从CAPP系统结构研究出发，利用特征技术，建立便于知识处理和规则学习的模糊神经网络工艺知识表达与生成模型，实现了CAPP系统结构的可迭加性和方法与数据的分离。应用特征技术表示产品的几何信息和工艺信息，实现了零件特征级工艺知识和工艺规程的组合与重用。在此基础上，采用异地分布式结构，便于网络模式下CAPP功能的实现，使CAPP能满足网络环境下快捷有效的信息传输和资源利用，是基于Web的CAPP系统有利于智能化与通用化实现的结构模式。给出了应用实例。     

航空遥感惯性稳定平台模糊/PID复合控制

为提高航空遥感惯性稳定平台控制系统稳定精度和扰动抑制能力,在常规PID控制的基础上设计了一种模糊控制与PID相结合的复合控制算法,分别应用于稳定平台横滚框及俯仰框系统进行实验验证。在三环控制系统位置环中将模糊控制与PID控制方法结合使用,并引入变论域思想,建立模糊/PID复合控制器,满足输出偏差变化不同时刻对PID参数整定的要求。通过模糊控制器实时调整PID参数,使系统具有良好的动、静态特性,实现多源扰动下惯性稳定平台的高稳定精度控制。分别通过仿真和静动态实验对方法进行分析和验证。实验结果表明:与常规PID控制及单纯模糊控制相比,模糊/PID复合控制器具有优越的扰动抑制能力和高稳定精度。相对传统PID控制,横滚框和俯仰框的静态均方根误差(RMS)值分别下降51%和73%、动态RMS值分别下降约20%和30%。     

Application of a hybrid simulated annealing-mutation operator to solve fuzzy capacitated location-routing problem

In the field of supply chain management and logistics, using vehicles to deliver products from depots to customers is one of the major operations. Before using vehicles, optimizing the location of depots is necessary in a location-routing problem (LRP). Also, before transportation products, optimizing the routing of vehicles is required so as to provide a low-cost and efficient service for customers. In this paper, the mathematical modelling of LRP is developed according to the existing condition and constraint in the real world. Maximum travelling time constraint is added, and we apply fuzzy numbers to determine customer demands, travelling time and drop time. The objective is to open a subset of depots to assign customers to these depots and to design vehicle routes, in order to minimize both the cost of open depots and the total cost of the routes. The proposed problem is modelled as a fuzzy linear programming (FLP), by applying the fuzzy ranking function method; the proposed FLP is converted to an exact linear programming (LP). A Lingo solver is used to solve this LP model in very small size. LRP is an non-deterministic polynomial-time hard (NP-Hard) problem, and because of the limitation of Lingo solver in solving medium, and large-size numerical examples, a hybrid algorithm including simulated annealing and mutation operator is proposed to solve these numerical examples. Also, a heuristic algorithm is proposed to find a suitable initial solution which is used in hybrid algorithm. At the end, a different analysis of the applied algorithm and a proposed model are introduced.     

以成本优化为平台的混流装配线排序

随着客户需求的日益多样化,混流装配线在工业生产中得到越来越多的应用.为了降低混流装配线的闲置和超载现象带来的成本浪费,在分析混流装配线的闲置和超载成本的基础上,提出一种最小化闲置和超载成本的排序模型,并应用粒子群算法来进行优化.优化综合考虑了粒子群算法中惯性权值的关键作用,给出了一种模糊自适应的惯性权值调整方法.最后将优化模型及算法应用到具体的混流装配线,验证了该方法的有效性.这种排序方法可以降低企业的生产成本,从而提高企业的效益,在企业内具有实际的应用价值.     

Reconfigurations of manufacturing systems—an empirical study on concepts, research, and applications

It is well known that the performance of a manufacturing system is susceptible to sudden changes in demand, either in terms of the quantity of products concerned or the product mix. Traditional manufacturing managers have been dealing with such situations by resorting to outsourcing of products; employing additional resources in terms of overtime, extra shifts, etc.; and adopting back logging policies using the goodwill of customers or making use of effective scheduling and inventory policies. However, in the recent times, they are also presented with the option of reconfiguring the manufacturing system (RMS), which offers a number of benefits. There are several keys enabling technologies to realize these benefits. The review of related literature helped in realizing that there are a number of alternative ways of resorting to reconfiguration. In this paper, the views and experiences of various researchers and practitioners as reported in literature are presented in an encapsulated manner bringing forth the multidimensional aspects of the subject area RMS. From various accounts reported in the international and Indian media, it is evident that the Indian manufacturing sector is performing well and is trying out various innovative practices; interestingly, many of which are related to RMS. A survey of Indian industries was carried out with the help of a survey using questionnaire as an instrument. The survey revealed various interesting facts about various RMS practices followed by the Indian manufacturing sector and the impact of reconfiguration on various performance measures of these organizations. The details of the survey and the findings of the same are also presented in this paper.     

An intelligent estimation method for product design time

The planning and control of product development is based on the pre-estimation of product design time (PDT). In order to optimize the product development process (PDP), it is necessary for managers and designers to evaluate design time/effort at the early stage of product development. However, in systemic analytical methods for PDT this is somewhat lacking. This paper explores an intelligent method to evaluate the PDT regarding this problem. At the early development stage, designers lack sufficient product information and have difficulty in determining PDT via subjective evaluation. Thus, a fuzzy measurable house of quality (FM-HOQ) model is proposed to provide measurable engineering information. Quality function deployment (QFD) is combined with a mapping pattern of “function→principle→structure” to extract product characteristics from customer demands. Then, a fuzzy neural network (FNN) model is built to fuse data and realize the estimation of PDT, which makes use of fuzzy comprehensive evaluation to simplify structure. In a word, the whole estimation method consists of four steps: time factors identification, product characteristics extraction by QFD and function mapping pattern, FNN learning, and PDT estimation. Finally, to illustrate the procedure of the estimation method, the case of injection mold design is studied. The results of experiments show that the intelligent estimation method is feasible and effective. This paper is developed to provide designers with PDT information to help them in optimizing PDP.     

Intranet/Extranet/Internet-Based Quality Information Management System in Expanded Enterprises

Because of e-commerce and the global economy, industries are challenged by world markets and modern enterprise morphologies, such as agile supply chains, expanded companies and virtual enterprises. Enterprises are thinking more and more about the market, customers and suppliers. Product quality is judged by the global market and the customers in the world village, and not only by the domestic market and customers. Enterprise quality assurance systems not only cover internal functional departments in an enterprise, but are expanding to external parties, such as customers, partners and suppliers, so, an expanded enterprise’s core competencies or leadership capabilities in quality assurance have to be strengthened by the complementary capabilities of partners. The traditional quality assurance technologies have to be innovated. It is reasonable that "customer focus" and "mutually beneficialsupplier relationships" blend into the core concepts of a quality management philosophy. As tools used by enterprises to support quality management, quality information management systems (QIMS) have to capture quality information from both internal and external parties, and to facilitate the communication environment, in order to share quality information among enterprises, customers and suppliers. Because of this, it is impossible for a traditional quality information management system based on the Intranet to meet these needs. In this paper, a model of the expanded enterprise is extended. A concept model and a functional model of the quality information management system based on Internet/Extranet/Intranet (IEI-QIS) are proposed. The system is able to integrate quality information from the enterprise, product customers and suppliers, and serves as a powerful tool to benefit the quality management of modern enterprises. A browser/server-based and the three-layer system architecture of IEI-QIS are also investigated. ID="A1"Correspondance and offprint requests to: Tang Xiaoqing, School of Mechanical Engineering and Automation, Beijing University of Aeronautics and Astronautics, Beijing 100083, PR China. E-mail: tanghuan@public.fhnet.cn.net     

基于DS444总线协议的吊具控制系统构建

用户因为互换性的要求,对采购上海振华重工(集团)股份有限公司的吊具提出特殊要求。为了满足用户的要求,根据当时市场上所能采购到的控制产品,构建该项目的吊具控制系统。文中介绍如何在硬件和软件上构建该吊具控制系统,以满足用户的要求。     

An ant colony system approach for fuzzy traveling salesman problem with time windows

Traveling salesman problem with time windows (TSPTW) is a well-known problem in logistics management. It seeks to find a minimum cost tour among customers while all customers are visited at their time windows. To better reflect the real situations of logistics management, this paper concentrates on customers’ satisfaction aspect of TSPTW, extends the basic mathematical modeling of the problem to fuzzy traveling salesman problem with time windows (FTSPTW), and presents an ant colony system algorithm to solve the problem. One advantage of this new modeling is its flexibility which enables us to optimize the delivery process in the network of customers with different satisfaction patterns and different priorities. The other advantage is that by the use of fuzzy time windows, not only customers’ preference for tolerable interval of time for service but also desirable time for service can be considered. Numerical results for a well-known benchmark problem and a real case study both confirm that optimization of the customers’ satisfaction is completely different from traditionally minimizing the total traveling time as well as the proposed algorithm which considers that customers’ favorites is completely superior to the algorithm that only pays attention to minimizing total travel time. These results provide an opportunity for future comparisons of different solution methods for the FTSPTW.     

一种新的机电设备状态趋势智能混合预测模型

针对机电设备运行状态受多因素影响,变化趋势复杂,难以用单一预测方法进行有效预测的问题,提出一种新的基于改进灰色系统一支持向量机一神经模糊系统的智能混合预测模型。该模型首先利用改进灰色系统弱化数据序列波动性、支持向量机处理小样本和模糊神经系统处理非线性模糊信息的优点,分别进行趋势预测,然后通过改进遗传算法对这三者的预测结果进行自适应加权组合。将该模型应用于信号随机波动性较强、趋势变化复杂的标准算例和某机组振动趋势的预测中,研究结果表明,该模型的预测性能均优于上述三种单一预测方法。     

Production planning and performance optimization of reconfigurable manufacturing systems using genetic algorithm

To stay competitive in the new dynamic market having large fluctuations in product demand, manufacturing companies must use systems that not only produce their goods with high productivity but also allow for rapid response to market changes. Reconfigurable manufacturing system (RMS) is a new paradigm that enables manufacturing systems to respond quickly and cost effectively to market demand. In other words, RMS is a system designed from the outset, for rapid changes in both hardware and software components, in order to quickly adjust its production capacity to fluctuations in market demand and adapt its functionality to new products. The effectiveness of an RMS depends on implementing its key characteristics and capabilities in the design as well as utilization stage. This paper focuses on the utilization stage of an RMS and introduces a methodology to effectively adjust scalable production capacities and the system functionalities to market demands. It is supposed that arrival orders of product families follow the Poisson distribution. The orders are lost if they are not met immediately. Considering these assumptions, a mixed integer nonlinear programming model is developed to determine optimum sequence of production tasks, corresponding configurations, and batch sizes. A genetic algorithm-based procedure is used to solve the model. The model is also applied to make decision on how to improve the performance of an RMS. Since there is no practical RMS, a numerical example is used to validate the results of the proposed model and its solution procedure.     

分布式信息共享平台框架体系和关键技术

为集成分散的铁路信息系统,实现信息共享,建立了分布式信息共享平台。设计了一个分层次、多要素综合的网络信息系统架构,并根据信息与应用的异域、异构、分布等特征,分别从事务完整性、网络交互协议、元数据动态导航、标准体系和管理体系等方面进行重点研究。该平台在现有交易中间件、Web中间件技术和应用服务器内部系统控制技术的基础上引入ODBC标准,以简单对象访问协议作为客户/服务器之间的交互方法。大量的实际应用表明,分布式信息共享平台可大大简化应用实现的复杂性,增强系统的模块化,提高应用的可靠性,具有较好的社会和商业应用价值。     

Effect of reconfiguration costs on planning for capacity scalability in reconfigurable manufacturing systems

In a globally competitive market for products, manufacturers are faced with an increasing need to improve their flexibility, reliability, and responsiveness to meet the demands of their customers. Reconfigurable manufacturing systems (RMS) have become an important manufacturing paradigm, because they broadly encompass the ability to react efficiently to this environment by providing the exact capacity and functionality needed when needed. This paper studies how such new systems can manage their capacity scalability planning in a cost effective manner. An approach for modeling capacity scalability planning is proposed. The development of the model is based on set theory and the regeneration point theorem which is mapped to the reconfigurable manufacturing paradigm as the capacity scalability points of that system. The cost function of the model incorporates both the physical capacity cost based on capacity size and costs associated with the reconfiguration process which referred to as the scalability penalty cost and scalability effort cost. A dynamic programming (DP) approach is manipulated for the development of optimal capacity scalability plans. The effect of the reconfiguration costs on the capacity scalability planning horizon and overall cost is investigated. The results showed the relation between deciding on the optimal capacity scalability planning horizon and the different reconfiguration costs. Results also highlighted the fact that decreasing costs of reconfiguration will lead to cost effective implementation of reconfigurable manufacturing systems.     

Variable-order fuzzy fractional PID controller

In this paper, a new tuning method of variable-order fractional fuzzy PID controller (VOFFLC) is proposed for a class of fractional-order and integer-order control plants. Fuzzy logic control (FLC) could easily deal with parameter variations of control system, but the fractional-order parameters are unable to change through this way and it has confined the effectiveness of FLC. Therefore, an attempt is made in this paper to allow all the five parameters of fractional-order PID controller vary along with the transformation of system structure as the outputs of FLC, and the influence of fractional orders λ and μ on control systems has been investigated to make the fuzzy rules for VOFFLC. Four simulation results of different plants are shown to verify the availability of the proposed control strategy.     

Roughness and Lubricant Effect on 3D Atomic Asperity Contact

Large-scale molecular dynamics simulations were performed to study the sliding process of rough surfaces with and without lubricant. In the dry contact, a linear relationship has been observed between the load and the contact area for surfaces with large root mean square (RMS) roughness. However, it becomes nonlinear when the RMS is small. In the presence of adhesion, small roughness results in a large friction force when the surfaces are flattened and the contact area reaches 60 %. In order to confirm this observation, nonadhesive models have been established with an observation that under the combined influence from roughness and adhesion, the contact area plays a crucial role to determine whether the dry sliding is under the domination of roughness or adhesion. In the lubricated sliding, an increase in friction force has been found for the partially lubricated condition because the asperity contact still accounts for a great deal of resisting force. Besides, the lubricant exerts a comparable resisting force to the sliding.     

[服务型制造规划和实施]基于服务蓝图的服务型制造系统流程改善研究

针对产品制造和服务提供相融合的服务型制造系统流程改善问题,在服务型制造和服务蓝图耦合的基础上,构建了基于服务蓝图的服务型制造系统,并依据系统特征,给出了基于模糊树图的系统流程改善方法,实例分析验证了该系统流程改善方法的有效性。研究表明：基于服务蓝图的服务型制造系统能够快速响应客户的异质化需求,且系统流程改善的结果在时间、柔性、成本和质量等指标方面均能得以体现,这有助于制造企业服务价值创造的实现,以及客户通过参与获取差异化的高品质服务。     

汽车主减速器轴承失效征兆早期识别的评价法

对汽车主减速器主齿轴承进行寿命预估,开展了主齿轴承失效的试验研究.为了对轴承失效征兆早期识别进行评价和判断,提出了运用模糊理论和Dempster-Shafer证据理论相结合的信息融合的评估方法,以处理信息的不确定性.试验中模拟汽车的运行状态,使用振动加速度传感器、噪声传感器和红外温度传感器,对同一测试区内的多传感器进行分析融合.试验结果表明,从冗余的信息中可以得到轴承的运行状态隶属于单一的征兆之内,产生比单一信息源更精确、更完全的识别和判断,同时避免了未知先验概率的缺乏,又达到了失效征兆识别的目的.这说明证据理论与模糊推理相结合的信息融合方法在进行轴承失效试验时,对征兆早期识别具有更高的可信度和良好的早期故障识别能力.