虚拟车间异地制造资源集成方法

集成异地制造资源是虚拟车间的基本要求,需要解决资源模型标准化、克服硬软件平台异构性和制造资源评价与选择三个方面的问题。建立了用于一个制造执行系统的制造资源数据模型,采用了CORBA技术解决异地、异种数据库读写问题,应用了模糊层次分析方法进行制造资源评价与选择。     

Stigmergic cooperation mechanism for shop floor control system

Inspired by the collective behaviour of ant colonies, a stigmergic cooperation mechanism for shop floor control is proposed. In stigmergic shop floor control systems, one piece agent takes charges of one work piece and chooses a manufacturing resource for it in the light of pheromones stored in information environment. Piece agents also update these pheromones to guide subsequent agents routing. Experiments confirm that a stigmergic cooperation mechanism has an excellent scheduling performance in a static environment, good suitability for the stochastic machining-time problem and good adaptability to shop floor changes.     

一种基于 RFID的制造车间实时定位算法研究

针对LANDMARC系统在制造车间定位应用中存在的问题,提出一种基于RFID的制造车间实时定位改进算法。从研究基于LANDMARC系统的制造车间定位技术入手,深入分析了系统在实施过程中存在的问题,重点阐述了改进最佳邻居算法的定位流程及关键模块设计,最后在搭建的实验室模拟环境中进行了定位测试。测试结果表明,改进算法的平均定位误差可以达到0．5m,定位精度对比LANDMARC算法提高了20％,能够很好地适应实验室模拟环境。     

多主体信息系统集成关键成功因素的实证研究

在分析一般IS/IT项目关键成功因素的基础上,结合多主体信息系统集成项目的特点,提出项目管理、知识管理、项目环境是多主体信息系统集成项目的关键成功因素.通过对238份有效问卷的实证研究发现,项目管理有项目控制和项目协调两个维度,知识管理有知识共享与扩散、知识重用两个维度,项目环境有IT规划、管理基础和IT技术三个维度.路径分析结果表明,知识管理对系统集成项目的时间、费用和质量目标的实现均有显著影响;项目管理对时间、费用目标的实现也有显著影响,但对质量目标的实现影响不显著;项目环境对质量目标的实现影响显著,但对时间、费用目标的实现影响不显著.     

基于知识域依赖的系统集成知识扩散路径优化

将产品设计结构矩阵引入信息系统集成知识扩散中,构建了知识域依赖矩阵模型,提出以依赖关系知识扩散路径替代全领域知识扩散路径的优化策略,并结合知识域的静态特征（共享程度）与动态特征（变动幅度）对依赖关系进行修正,以实现扩散路径的进一步取舍优化。     

Interpolating model identification for SISO linear parameter-varying systems

This paper presents a new method to estimate linear parameter-varying (LPV) state-space models for single-input single-output systems whose dynamics depend on one or more time-varying parameters, called scheduling parameters. The method is based on the interpolation of linear time-invariant models that are identified for fixed operating conditions of the system, that is, for constant values of the scheduling parameters. The proposed method can account for multiple scheduling parameters and yields either a polynomial or an affine LPV model that is numerically well-conditioned and therefore suitable for LPV control synthesis. The underlying interpolation technique is formulated as a nonlinear least-squares optimization problem that can be solved efficiently by standard solvers. The new interpolation method is applied to an electromechanical system that depends on two scheduling parameters. The numerical results are compared to existing techniques in the literature, demonstrating the potential and advantages of the proposed method.     

基于演示与讨论方法的企业信息化实施过程模型

为了提高企业信息化实施的成功率和效益,提出了一种基于演示与讨论方法的实施过程模型。将企业信息化实施过程分为规划和实施两个主要的阶段,并用IDEF0方法详细描述了每一个阶段包含的过程以及过程之间的关系。该模型以企业为实施主体、面向信息化全过程,可以为实施过程管理和导航提供有效的支持。     

A framework for capacity planning and machine configuration in flexible assembly systems

We consider the problem of simultaneously determining the number of machines (and/or workers), the assignment of tasks (and related tools and components) to these machines, and the number of jobs circulating in a flexible assembly system (FAS), to satisfy steady-state throughput requirements for a family of similar products at minimum cost. We focus on situations where there are precedence relations among the various tasks, as is common in assembly systems. We present a framework for solving this problem based on a heuristic decomposition approach which involves the solution of only a few types of sub-problems. We demonstrate the efficiency and effectiveness of the overall procedure using a number of example problems.     

基于XML和Agent的流程工业系统信息集成框架

为了实现流程工业系统的有效集成,提出了一种基于可扩展标记语言和Agent的系统信息集成模型。首先,用可扩展标记语言和Agent技术把各个过程运行子系统包装成为Agent;然后,根据过程运行系统的集成目标集成这些分布在不同区域的Agent。该模型利用Agent技术来实现过程运行子系统的包装,保证了这些子系统在集成平台中仍能保持原先的安全稳定性;同时,使用可扩展标记语言来表达不同系统之间的交互信息,保证了集成模型具有良好的跨平台特性。最后,通过在建立Tennessee Eastman过程多任务信息集成平台上的实际应用,验证了该集成技术的有效性及实用性。     

A practical taxonomy of methods and literature for managing uncertain spatial data in geographic information systems

Perfect information is seldom available to man or machines due to uncertainties inherent in real world problems. Uncertainties in geographic information systems (GIS) stem from either vague/ambiguous or imprecise/inaccurate/incomplete information and it is necessary for GIS to develop tools and techniques to manage these uncertainties. There is a widespread agreement in the GIS community that although GIS has the potential to support a wide range of spatial data analysis problems, this potential is often hindered by the lack of consistency and uniformity. Uncertainties come in many shapes and forms, and processing uncertain spatial data requires a practical taxonomy to aid decision makers in choosing the most suitable data modeling and analysis method. In this paper, we: (1) review important developments in handling uncertainties when working with spatial data and GIS applications; (2) propose a taxonomy of models for dealing with uncertainties in GIS; and (3) identify current challenges and future research directions in spatial data analysis and GIS for managing uncertainties.     

Simulation of flexible automated systems for the discrete production of metal components by forging and machining

The integration of metal forming and metal removal operations in a single flexible manufacturing cell will advance further the area of application of the flexible manufacturing system and will contribute to the flexible automation of traditionally high volume applications. Forming operations will first be employed to achieve a near net shape of the components, so that only a minimum of subsequent machining operations will be required to manufacture the final forms. The efficient use of these systems depends considerably on the proper design of the system. A simulation model written in the PASCAL language is presented, capable of simulating a mixed type FMC. With the aid of this model the effect of the batch size and the carrying capacity of the pallets on utilisation of the machine tool and the throughput times of the orders is examined.     

基于粗糙集的不完备信息系统空值估算方法

针对基于相似关系模型的空值估算方法存在的不足,从群体决策的角度提出了一种改进方法.通过定义属性的向域和对象的简单多数规则率,将其结合用于空值估算,从而无需原方法的投票策略就能实现不完备信息系统的完备化,并消除了原方法可能出现的对象无相容类问题和投票策略潜在的多众数、无众数问题,得到的估算结果在覆盖率和准确率两方面均优于原方法.通过算例及应用示例表明了本文方法的有效性.     

产品设计与仿真的集成信息模型与异构信息转化技术研究

针对目前产品设计与仿真分析系统之间的信息难以共享与重用,影响仿真效率等问题,提出了产品设计与仿真的集成信息模型与异构信息转化技术.分析了产品设计与仿真集成信息模型的结构组成,研究了三维几何建模系统、多体动力学系统、有限元分析系统,以及知识管理各系统之间的信息集成和数据转化技术,实现了产品设计与仿真分析的综合信息的集成.该方法已在产品开发中得到应用.     

A methodology for investigating effects of cell size on operational flexibility in flexible manufacturing systems

There are two aspects to cell formation in flexible manufacturing systems, cell sizing or deciding on the optimum number of machines to be allocated to each cell, and then allocation of specific machines to each cell. Although the latter problem has been investigated extensively there is a paucity of published work on the former. This paper discusses the effects of cell sizing on operational flexibility.Operational flexibility is that aspect of flexibility that enables manufacturing systems to respond with speed and efficiency to changes in the manufacturing environment while maintaining an effective level of control.     

A systematic approach for the sequence controller design in manufacturing systems

This paper presents a systematic approach for the design and implementation of the sequence controller in manufacturing systems. By employing the IDEF0, we construct the simplified Petri net controller (SPNC) through the material flow diagram and the information flow diagram. Then, the ladder logic diagram (LLD) can be transformed from the SPNC through the token passing logic (TPL). The proposed approach, including the IDEF0, SPNC, and TPL tools, leads to the standard IEC1131-3 LLD for PLC implementation. Finally, an application of a stamping process is provided to illustrate the design procedure of the developed approach .     

A super-efficiency model for measuring aggregative efficiency of multi-period production systems

This paper proposes a super-efficiency model for measuring aggregative efficiency of multi-period production systems. The proposed model does not require any information on price data or preferential weighings of inputs and outputs over multiple periods and able to measure aggregative efficiency of multi-period production systems. The model computes efficiency score of each decision making unit (DMU) in each period. At the same time, the model classifies DMUs and ranks the fully efficient ones. Besides, the model provides a new technique for reducing the computational complexity of a recently introduced model. The proposed method is illustrated with a numerical example and proves to be effective and practical.     

A fast iterative recursive least squares algorithm for Wiener model identification of highly nonlinear systems

In this paper, an online identification algorithm is presented for nonlinear systems in the presence of output colored noise. The proposed method is based on extended recursive least squares (ERLS) algorithm, where the identified system is in polynomial Wiener form. To this end, an unknown intermediate signal is estimated by using an inner iterative algorithm. The iterative recursive algorithm adaptively modifies the vector of parameters of the presented Wiener model when the system parameters vary. In addition, to increase the robustness of the proposed method against variations, a robust RLS algorithm is applied to the model. Simulation results are provided to show the effectiveness of the proposed approach. Results confirm that the proposed method has fast convergence rate with robust characteristics, which increases the efficiency of the proposed model and identification approach. For instance, the FIT criterion will be achieved 92% in CSTR process where about 400 data is used.