单向循环搬运系统交叉环布局优化问题研究

目的为了提高单环单向循环搬运系统的搬运量和系统效率,在单环单向循环搬运系统中增加交叉环且优化交叉环的布局(设置位置及数量)可以避免小车间不必要的等待时间,为搬运系统提供捷径,且提高搬运效率。方法构建系统的数学模型并对不同交叉环布局(设置位置及数量)进行理论分析,在2种基本调度算法下进行仿真实验优化。结果通过理论和仿真实验分析得出,2种基本调度算法下,交叉环设置为布局1时的系统干涉情况最小,但系统单位时间搬运量较少;交叉环设置为布局4时系统单位时间搬运量最大,但系统干涉增加。结论从减少能源消耗(干涉)的角度优化,交叉环应设置1条且设置在系统正中间位置,系统干涉时间最小,单位时间搬运量也最少;从单位时间搬运量最大的角度优化,应在每2个处理站点中间设置多条交叉环,单位时间搬运量最多,但系统干涉时间最大。     

Advances in discrete material handling system design

The paper presents an outline of the research done in the area of facility layout and discrete material handling system design. The objective of this paper is to observe the trend in the literature in the area of manufacturing system design and predict the direction of future research in this area. The paper attempts to link the areas of facility layout design and material flow network design. A methodology for solving the integrated design problem is presented. An algorithm which aids in solving the combined pick-up/drop-off point location and material handling flowpath problem is outlined.     

一种新型物料装置在汽车零部件生产中的应用研究

介绍一种由新型材料制作适用于中小型零件加工、装配和搬运的组合式物料装置及其在汽车零部件生产中的应用。用该材料设计制作的组合式物为装置具有轻便、灵活、可重复使用等特点,能够有效地提高生产率和降低工人的劳动强度。     

Assignment rules in robotic mobile fulfilment systems for online retailers

We study robotic mobile fulfilment systems for online retailers, where products are stored in movable shelves and robots transport shelves. While previous studies assume random assignment rule of workstations to robots, we propose an assignment rule based on handling speeds of workstations and design a neighbourhood search algorithm to find a near optimal assignment rule. We build semi-open queueing networks and use a two-phase approximate approach for performance estimation. We first replace workstation service processes by a composite service node and then solve the model by the matrix-geometric method. Simulations are used to validate the analytical models. Numerical experiments are conducted to compare random, handling-speeds-based, near optimal and optimal assignment rules, in terms of retrieval throughput time. The results show that the random assignment rule is not a good choice, the handling-speeds-based assignment rule significantly outperforms the random assignment rule when the workers have large handling time difference, and the neighbourhood search approach can provide an assignment rule that is very close to the optimal one, using a much shorter time. Moreover, we design the shelf blocks under the examined assignment rules, and find that the optimal width of shelf block decreases with the width to length ratio.     

Development of the Swedish bridge management system by introducing a LMS concept

The Swedish Road Administration (SRA) has developed an information technology (IT) based bridge and tunnel management system (BaTMan) that is widely implemented by the organisation. The system is a tool for operational, tactical and strategic management. However, this system does not include systems and tools for managing optimisation and long-term planning of␣Maintenance, Repair and Rehabilitation (MR&R) actions due to service life performance aspects. This paper discusses the need of service life performance analysis for sound optimisation and long-term planning of MR&R actions in the bridge management. The paper presents a service life performance analysis model that is based on a Markov chain model and the MEDIC method. The model is developed to manage different kinds of degradation characteristic and yet present a uniform result expressed in conditional probabilities. The paper discusses also the need of systems and tools for describing objects on both an overall level and on a component level.     

基于仿真的半导体自动物料搬运系统调度优化

利用Arena仿真软件对半导体制造中的Intrabay系统进行了仿真建模,根据关键因子和等待比例两个变量将系统状态分为三种情况,利用遗传算法与仿真模型结合来确定两个变量的阈值和三种系统状态下各自采用的调度规则,实现系统的动态调度。仿真实验表明,所确定的调度规则比使用静态调度最长等待时间规则获得了更好的性能指标。     

An integrated scheduling and material-handling approach for complex job shops: a computational study

We suggest an extension of the shifting bottleneck heuristic for complex job shops that takes the operations of automated material-handling systems (AMHS) into account. The heuristic is used within a rolling horizon approach. The job-shop environment contains parallel batching machines, machines with sequence-dependent setup times, and re-entrant process flows. Jobs are transported by an AMHS. Semiconductor wafer fabrication facilities (wafer fabs) are typical examples for manufacturing systems with these characteristics. Our primary performance measure is total weighted tardiness (TWT). The shifting bottleneck heuristic (SBH) uses a disjunctive graph to decompose the overall scheduling problem into scheduling problems for single machine groups and for transport operations. The scheduling algorithms for these scheduling problems are called subproblem solution procedures (SSPs). We consider SSPs based on dispatching rules. In this paper, we are also interested in how much we can gain in terms of TWT if we apply more sophisticated SSPs for scheduling the transport operations. We suggest a Variable Neighbourhood Search (VNS) based SSP for this situation. We conduct simulation experiments in a dynamic job-shop environment in order to assess the performance of the suggested algorithms. The integrated SBH outperforms common dispatching rules in many situations. Using near to optimal SSPs leads to improved results compared with dispatching based SSPs for the transport operations.     

激光导引AGV的自动引导系统设计

 激光导引技术是目前AGV系统普遍采用的引导方法,柔性好和精确高是其突出特点．介绍了AGV的基本概念、导引方式、车体结构和运动控制方式,重点介绍了激光扫描车体方位计算原理并结合路径轨迹推算导向法,设计了激光导引AGV的自动引导系统的结构和软件功能。     

半导体晶圆制造中组合设备运行和控制综述

作为半导体制造中单晶圆加工技术的可重构集成设备,组合设备在半导体产业得到越来越广泛的应用.使用组合设备使得半导体制造产出更高、生产周期更短、空间利用率更高以及生产成本更低.由于组合设备的运行受限于诸多约束条件,有效运行一台组合设备相当困难.目前已有大量的有关组合设备建模、性能分析及调度等相关研究工作.本文回顾了这些研究工作的进展及其使用的研究方法,探讨了现有的方法的优缺点.基于这些分析,指出了进一步的研究方向.     

具有自动装卸搬运机器人的制造单元建模与分析

针对具有自动装卸搬运机器人的制造单元,着重考虑其双重资源约束的特点,提出了该系统的有限缓冲开排队网的建模方法。根据工件的加工、装卸与搬运等工艺流程,定义该系统的排队网模型的各种状态,基于连续时间马尔可夫链,采用精确解法对该模型进行分析求解,获得系统一系列的稳态性能指标。为了验证排队网建模方法的有效性,建立其对应的仿真模型,分别采用排队网模型的数值计算与仿真模型的仿真统计2种方法求出系统的性能指标进行对比,并基于排队网模型对该制造单元的系统性能进行分析,为该类制造单元的资源配置优化和设施布局优化等问题提供重要的理论支撑。