基于FMS技术模块化的机电一体化教学探讨

基于FMS技术的模块化机电一体化教学方法的探讨,有助于加深学生对机电一体化系统概念的理解,掌握柔性制造的内涵,把握未来制造业的方向,特别有助对学生培养学习的兴趣和专业技能的提高,培养机电一体化行业急需的复合型高级人才。     

基于FMS的自动化立体仓库监控系统开发与应用术

为了实现对基于柔性制造系统（FMS）的自动化立体仓库（AS／RS）的监控与管理,以浙江机电职业技术学院示范院校建设FMS项目为背景,根据具体实验教学的要求,进行了自动化立体仓库集成监控系统设计,实现了一套功能完备、规范化、工程化的集成监控软件。研究结果表明,该系统的运行效果令人满意。     

基于可复用调度策略的FMS刀具控制与仿真

刀具在现代生产中占据重要地位。在分析刀具流的基础上,提出可复用调度策略,即建立以中央刀库为平台的刀具信息管理系统,对系统使用的每把刀具主要信息如:编号、位置、使用情况、当前状态等进行实时监控及异常情况报告,并在该调度中制订了在多刀具或多任务时的优先机制。根据该调度策略思想进行了建模与仿真,仿真结果明了该刀具管理系统的实时性和有效性,并对不同刀具配置数量下的系统运行结果进行了比较分析。     

板材FMS的作业管理系统研究

论述板材加工柔性制造系统中作业管理系统的需求特点、数据模型及设计思路。对如何在管理流程中综合材料成本、计划交货期及资源利用等因素，实现板材加工自动化提出了较为合理的系统框架和实现方案。     

A Look-Ahead Routing Procedure for Machine Selection in a Highly Informative Manufacturing System

Many dispatching rules have been developed for the on-line control of product flow in a job shop. The introduction of a highly informative manufacturing system (HIMS) has added a new requirement to a classical job-shop control problem: the selection of machines by parts of different types. An HIMS can keep a great deal of information on the status of the system, such as information on what is scheduled in the near future with great accuracy, which can be used for shop floor control. For example, the knowledge of the time when the next parts arrive at the machines can be used for better routing. This article tests the effect of the use of this knowledge for part routing on the part's flow time and tardiness under a look-ahead routing procedure (LARP). LARP assigns a new part to a machine so that the assignment minimizes the flow time or tardiness of the current part and the next N parts arriving after the current part. A test shows that the reduction of part flow time is up to 11% and the reduction of tardiness is up to 21% for the cases with this procedure.     

Average-Cost Optimal Policies for an Unreliable Flexible Multiproduct Machine

This paper is concerned with optimal production planning on a single failure-prone flexible machine that produces N distinct part types. The machine is flexible in the sense that no setup is required for switching from production of one part type to another. We consider the problem of controlling production rates to minimize the expected long-run average cost of product surpluses over time. We assume constant unit holding and shortage costs and constant demand rates for the part types. Moreover, the costs are assumed to be the same for all products. We provide an explicit optimal solution for the problem.     

New Algorithm for FMS Scheduling Based on Multiagent System Architecture

Redefined benefit-driven function is used to study the dynamic scheduling of FMS based on multiagent architecture. Each agent is dedicated to a work center, i.e. a set of the manufacturing system. In one hand, each agent selects locally and dynamically the dispatching rule(DR) that seems to be most suited to the operating conditions, production objectives and current shop status. On the other hand, each task should bring certain amount of benefit for the manufacturer. So, it is reasonable to have the dynamic scheduling of FMS relying upon multiagent architecture using the benefit-driven function as a strategy. Well, today's manufacturing corporation, especially the high & new technology one and deep machining one, the cost of their products is mainly determined by how much the knowledge is input From this viewpoint, we redefined the benefit-driven function, hi the end, this approach is compared with other existing DRs on a job-shop problem, already used in other research works.     

一种基于组态有色Petri网的FMS建模方法

针对FMS物流过程的具体行为特性,提出了一种基于组件对象模型思想的有色Petri网建模方法,该方法具有模块化和层次化思想,最直接的好处就是可以简化FMS系统的建模过程。文中以一个具体的FMS物流系统的例子来说明如何使用组件对象模型以及有色Petri网对FMS物流过程建模。实际上该建模方法为离散动态事件系统的建模与分析提供了一个很好的解决途径。     

Revision on ‘Maximally permissive deadlock prevention via an Invariant Controlled Method’

All current design approaches of maximally permissive supervisors assume that forbidden and legal markings are linearly separable. Based on that implicit assumption, Liu et al. propose a novel method of optimal control of a problematic siphon to synthesise maximally permissive controllers. However, there are counter examples for which we could not produce optimal solutions. This occurs when forbidden and legal markings are not linearly separable even though it rarely happens. Verifying linear separability involves solving a large set of linear inequalities and is quite time consuming. This paper aims to relieve this problem via enhancing our critical-siphon approach. Specifically, we propose to: (1) find an efficient method to detect linear inseparability; (2) construct best suboptimal control models; (3) find all lost legal markings; and (4) identify the linear equations that violate linear separability. Each above contribution is unique and pioneering.     

Minimal strict siphons extraction for S3PMR

Abstract

A siphon is an important structure object for deadlock control. Insufficiently marked siphons lead to deadlocks. Deadlock occurs due to inappropriate resource sharing. Hence most of the research focuses on the minimal siphon extraction problem covering a set of places representing resources, which, for general Petri Nets is known to be an NP‐Complete problem. Control places and arcs are often added to the original net to prevent a siphon from becoming insufficiently marked. The number of siphons grows rapidly with the size of the net leading to very complicated control nets. Efficient enumeration of problematic siphons is an urgent research topic. Earlier, we proposed fast algorithms to find all such siphons for both S³PR and S²CPR (System of Synchronized Choice Processes with Resources). However, it was assumed that siphons occur between adjacent processes. This paper removes this assumption and develops an algorithm for S³PMR which is more powerful than S³PR by allowing a state to use more than one resource and than S²CPR by allowing more than one state to use the same resources. Comparisons with previously published work have been made.