基于SLP和Em-plant的变速器装配线规划研究

以汽车变速器装配线为研究对象,用SLP理论和Em-plant仿真相结合的方法进行变速器装配线规划,以缩短设计周期,提高设计质量.以长城汽车变速器装配线的设计规划过程为例,首先用SLP理论对装配线的主线体以及外围物流通道进行规划,然后用Em-plant仿真软件对规划的线体进行仿真验证,进一步平衡各工位.结果显示装配线的线体布置和物流通道合理,工位之间的平衡性高.由此可以得出,用SLP理论和Em-plant仿真相结合的方法进行变速器装备线的设计规划,条理性强,能够兼顾线体物流和平衡性两方面的要求,能够提高我国变速器装配线的设计水平.     

装配线仿真流程及其案例研究

针对目前装配线仿真研究缺少模型检验步骤而导致仿真结果不可信的问题,在总结目前装配线仿真研究的基础上,引入两次仿真模型有效性的检验过程,提出完整的装配线仿真流程。为验证该流程的有效性,以实际装配线为例,在分析布局与工艺流程的基础上,考虑物流线布局、瓶颈机器数量、AGV数量和AGV速度对产能的影响,设计并基于Plant Simulation软件建立24种方案。所有方案仿真模型有效性的检验通过后,通过比较各方案的产能与机器利用率得到最佳方案。仿真结果表明,优化后的产能较初始方案提升约227%,瓶颈机器利用率提升约51%,平均机器利用率提升约121%。所提仿真优化流程可行且有效,可为装配线仿真研究与应用提供指导,对其他生产领域的仿真研究也具有借鉴意义。     

基于仿真优化方法的混合装配线平衡

针对混合装配线平衡问题传统求解方法的局限性,提出采用仿真优化方法求解该问题。基于最小化工作站和仿真优化方法,分别建立以均匀化各个工作站平均负荷和瞬时负荷为目标的数学模型和仿真模型,并设计了遗传算法作为优化算法。根据仿真优化的原理构建了仿真优化系统并针对系统运行费时的特点,提出了相应的改进方法。通过实际例子验证了方法的可行性。     

基于eM-Plant软件的液压支架装配线物流仿真与优化

以eM-Plant软件为平台,对混流装配线进行仿真建模.在某液压支架项目建成之前,对订单所包含的产品种类、型号规格、需求数量、交货期及物流配送情况进行仿真,并合理优化小车数量、速度和装载量等参数.认为AGV小车为5台,运行速度为1.2m/s,运载量为20件的方案较优.     

动态参数摄动系统可视化建模及群仿真研究

研究了动态参数摄动系统的可视化群仿真环境的软件实现问题，研究表明，应用先进仿真技术，采用面向结构化设计方法，即可实现参数摄动条件下的交互式可视群仿真。     

基于C＋＋的排队系统仿真研究

排队论已经广泛的应用于各种管理系统。在系统仿真应用中，又以排队系统的离散型仿真最为普遍。本文首先对排队系统及其仿真进行概述，接着通过c＋＋语言实现火车票代售票点排队过程的仿真，该仿真的数学模型是m/m/1，最后对仿真结果进行了验证，证明该仿真的真实性。     

装配线平衡系统研究与开发

装配线的平衡问题已有大量理论研究,但缺乏应用工具.为了消除该问题理论与实际应用之间的鸿沟,利用有效的算法,开发了一个装配线平衡的系统.简要介绍了装配线平衡问题及其求解算法,阐述了系统的功能及其实现过程.企业界的工程技术人员利用该系统可以有效地解决装配线平衡问题,从而提高装配线的生产效率.     

基于标准作业时间和仿真的装配线规划

在分析装配线规划内容的基础上,提出了基于标准作业时间及系统仿真的装配线规划方法并开发了相应的原型系统。通过建立装配操作树,定义装配操作约束,规划合理平衡的装配工位,同时生成装配作业表。以此作业表为输入,建立装配线的仿真模型,为装配线系统布置中的流参数等优化提供环境。通过这些工作,为企业制定工时定额合理的装配线,提高自主规划生产系统的能力提供途径。     

制造系统面向营销的三维可视化仿真

针对制造系统提出了推广实施先进可视化仿真技术的方法。即面向市场，客户驱动的策略，它把设备布局，工艺仿真和快速报价集成起来，快速，有效地对客户需求做出反应。从而抓住市场时机，这一策略已成功地应用于啤酒灌装生产线的三维可视化仿真项目中。     

批量独立可修件的备件需求预测仿真算法

利用Monte Carlo随机仿真技术，采用事件调度法的仿真策略对可修件的使用与维修过程进行仿真，给出了在给定备件和维修分队数量下批量独立可修件的备件保障概率仿真算法，并用一系列计算实倒证明了算法的可行性和正确性，该算法能有效解决安装在不同装备上，具有不同已工作时间、不同故障间隔时间分布、不同修复时间分布的可修件的备件保障概率计算问题，为备件的科学储备提供7有力的决策依据。     

Modelling and simulation of automated manufacturing systems for evaluation of complex schedules

Automated manufacturing systems have been studied widely in terms of scheduling. As technology evolves, the behaviour of tools in automated manufacturing systems has become complicated. Therefore, mathematical approaches to the analysis of complex schedules no longer reflect reality. In this paper, we propose a systematic way of conducting simulation experiments to evaluate the complex operating schedules of automated manufacturing systems. A simulation model is based on a timed Petri net to take advantage of its mathematical strength. Since a Petri net cannot itself have token firing rules, we introduce additional states called operational states. Operational states are not directly related to a Petri net, and are only used for decision making. In addition, a decision function that is responsible for the conflict resolution of a Petri net model and an operational state transition function are introduced. The parallel simulation concept is also suggested by dividing a Petri net into several independent decision sub-nets. A multi-cluster tool system for semiconductor manufacturing is analysed as an application.     

ProModel的服装缝制流水线仿真及应用

对S公司的服装缝制流水线编排情况进行研究,建立了基于ProModel的仿真模型.将仿真模型运行情况与实际情况进行对比,确定模型的有效性,并运用该模型运行结果分析实际流水线生产情况,有针对性地提出改进措施并仿真,根据仿真结果对流水线进行了优化.结果表明,在考虑和处理诸如回修、搬运等因素的影响时,仿真方法相比手工编制方法具有明显的优势,有利于企业更有效地提高流水线的生产效率和实现对生产进度的准确把握.     

Agent-based manufacturing control based on distributed bid selection and publish-subscribe messaging: a simulation case study

Bidding-based negotiation schemes play a major role in multi-agent manufacturing systems research. Despite some concerns with message congestion, researchers have been proposing and studying negotiation schemes based on the contract net protocol (CNP). On the other hand, research in robotics has considered a variant of CNP based on publish-subscribe messaging designed for multi-robot coordination. A distinct feature of this variant involves distributing the bid evaluation and selection functions among robot agents. This paper discusses our adaptation of this design variant for multi-agent manufacturing systems and examines its performance implications. Using discrete-event simulation, we study how the adapted CNP design can help address the message congestion problem by cutting down on negotiation slack time. Our case study results show that it can enhance the resilience of the agent negotiation process to message congestion, thereby contributing to the overall performance of a multi-agent manufacturing system.     

Workshop Scheduling Based on a Rule-restrained Colored Petri Net and the Development of a Scheduling System on the Internet／Intranet

In the paper, the gap between theoretical research and practical applications of workshop scheduling is analyzed. According to practical application requirements, the traditional Petri net is expanded and a Rule-restrained Colored Petri Net(RCPN) is put forward to model workshop activities. Then, the architecture of the workshop scheduling system based on RCPN is presented. Finally, the scheduling system that adopts a 3-layer B/S/D mode is developed on the Internet/Intranet by using the Web database and lava.     

An overview of discrete event simulation methodologies and implementation

Discrete event simulation has been widely used to model and evaluate computer and engineering systems and has been an on-going area of research and development. This paper presents an overview of the field. It covers specifications of discrete event systems, simulation methodology, simulation languages, data structures for event management, and front and backend support in simulation packages including random number generation and resource management. The emphasis of the survey is on simulation methodology and event scheduling, which forms the core of any simulation package or environment.     

基于虚拟现实的截流施工动态可视化仿真研究

利用虚拟现实和3dsmax技术进行了截流施工场景三维仿真建模,并在此基础上,结合龙口水力指标的动态计算,提出了基于虚拟现实的截流施工三维动态可视化仿真技术,实现了截流过程的逼真预演和多方案的比较分析,从而为截流组织设计与决策提供了强有力的可视化分析手段。     

Capacity planning through queueing analysis and simulation-based statistical methods: a case study for semiconductor wafer fabs

This paper presents a comprehensive framework for the strategic capacity expansion of production equipment in semiconductor manufacturing, and the proposed approach is applied to a model of an actual wafer fabrication facility. It is the intention of this work to show that, once intelligently integrated, an analytical queueing model and a numeric computer simulation model can be used synergistically and can lead to a better alternative method than methods restricted to only one of them. The outcome of our methods is a number of good system configurations, each of which is characterised by its cycle time (CT)–throughput (TH) profile. Such profiles fully describe the system's comprehensive performance over a wide range of demand scenarios (involving varying product mix), and hence can be used to thoroughly evaluate alternative configurations in capacity expansion decisions.     

Scheduling a dynamic flexible flow line with sequence-dependent setup times: a simulation analysis

This paper presents a simulation-based experimental study of scheduling rules for scheduling a dynamic flexible flow line problem considering sequence-dependent setup times. A discrete-event simulation model is presented as well as eight adapted heuristic algorithms, including seven dispatching rules and one constructive heuristic, from the literature. In addition, six new proposed heuristics are implemented in the simulation model. Simulation experiments are conducted under various conditions such as setup time ratio and shop utilisation percentage. One of the proposed rules performs better for the mean flow time measure and another one performs better for the mean tardiness measure. Finally, multiple linear regression based meta-models are developed for the best performing scheduling rules.     

Loading and sequencing heuristics for job scheduling on two unrelated parallel machines with long,sequence-dependent set-up times

The purpose of this paper is to develop and test intelligible heuristics for the scheduling of production orders that can easily be used in practice. Grounded in a case study, this paper examines the combined effects of assignment and sequencing heuristics on commonly used performance indicators. Discrete event simulation is used in the analysis to adequately capture the complexity found in the case study: production orders differing in many aspects, two unrelated parallel machines with varying and product-specific speed, and set-up times that depend on the (dis)similarity of successive orders. Evaluating 108 strategy–scenario combinations including the base case derived from the case study, it is found that a loading heuristic based on order quantity and scheduled capacity in combination with the shortest set-up heuristic performs best. When compared to the heuristic approach used by the case company, this strategy saves about 13.9% of total machine busy time and increases service level by 10.2%. In addition, using a reduced set of 40 production orders we are able to demonstrate that the best heuristic strategies comes close to results generated in a two-stage optimisation. The gap to optimality is only 3.1% in total busy time on average over all scenarios.