模糊柔性制造系统的混杂Petri网建模与调度

对模糊柔性制造系统的建模和调度进行了研究.定义了一种具有模糊区间速率的混杂Petri网模型,提出了模型的迁移使能和迁移引发语义,定义了弱使能迁移的模糊使能规则,给出了模型动态演变算法.建立了模糊柔性制造系统调度的模糊线性规划模型,并对典型的工业实例进行了分析.研究结果表明,基于所定义的混杂Petri模型能够有效地描述和分析模糊柔性制造系统.     

Impact of operation flexibility and dispatching rules on the performance of a flexible manufacturing system

Operation flexibility is one of the eight common types of flexibility that exist in flexible manufacturing systems. Dispatching rules are commonly used in loading the machines. This paper studies the effects of different levels of operation flexibility and various dispatching rules on the performance of a flexible manufacturing system. The system performance considered is mean flow time. Simulation results indicate that the mean flow time cannot be always improved by increasing the level of operation flexibility. Altering the dispatching rules seems to have a more significant effect on the mean flow time performance than changing the level of operation flexibility.     

基于数字化人的柔性制造系统的研究

基于人机一体化思想,在计算机技术和无线移动通信技术的支持下,将“数字化人”的概念引入柔性制造系统车间中,在此基础上构建了数字化人-机协同柔性制造系统,给出了整体结构图,并详细研究了数字化人-机协同柔性制造系统中的关键技术:基于Web服务技术和移动技术的新型数控系统、蓝牙移动自组网技术、基于多Agent移动计算的人机协同管理调度技术.最后,通过一个实例实现了基于数字化人的人机协同柔性制造过程.     

基于模糊逻辑的立体仓库入库货位指派系统的研究

入库货位分配系统是影响自动化立体仓库运行效率的关键因素之一。针对制造业立体仓库的特点,提出了基于模糊逻辑的方法对入库货位进行分配,选取货品重量、货品周转率和货位的仓库空闲状态作为模糊逻辑的输入变量,通过模糊推理,得到货品的入库货位。在数字化车问的运行验证了该入库货位分配方法的有效性和先进性。     

Dynamic load control policies for a flexible manufacturing system with stochastic processing rates

Real-time scheduling and load controls of FMSs are complex processes in which the control logic must consider a broad spectrum of instantaneous state variables while taking into account the probabilistic future impact of each decision at each time epoch. These processes are particularly important in the management of modern FMS environment, since they are known to have a significant impact on the FMS productive capacity and economic viability. In this article we outline the approach developed for dynamic load controls within an FMS producing a variety of glass lenses. Two revenue-influencing objective functions are evaluated for this capital-intensive facility. It is shown that by using Semi-Markovian modeling concepts, the FMS states need to be observed only at certain decision epochs. The mean holding time in each state is then obtained using the probability distribution function of the conditional state occupancy times. Several key performance measures are then derived by means of the value equations. In addition, the structure of the optimal policies are exemplified for a variety of operational parameters. It is shown that the optimal policies tend to generate higher buffer stocks of parts in those work centers having the highest revenue-generation rates. These buffer stocks get smaller and smaller as the relative processing capacity of the centers increases. Similar observations lead us to the introduction of several promising heuristics that capture the structural properties of the optimal policies with a significantly smaller computational effort. Results of the empirical evaluation of these heuristics are also analyzed here.     

基于模糊神经网络的电网调度自动化控制系统

为了提高电网的调度效果,解决当前电网调度自动化控制系统存在的控制功能不佳的问题,利用模糊神经网络算法,从硬件、数据库和软件功能三个方面,实现控制系统的优化设计。改装数据采集器、控制器等设备元件,通过改装供电电路的连接,完成硬件系统的优化。从逻辑和物理两个方面,构建系统数据库,存储电网调度相关信息。在硬件设备和数据库的支持下,收集电网实时运行数据,利用模糊神经网络算法预测电网调度负荷,结合电网理想调度数据,度量调度控制量,进而完成系统的电网调度自动控制功能。通过系统测试实验得出结论:设计系统的IAE指标和容载平衡指数均低于预设值,即设计系统具有良好的控制效果。     

基于Arena RT的柔性制造单元控制系统仿真

从物理仿真模型型的控制逻辑和模型中资源的组织形式出发,提出了一种基于Arena RT的柔性制造单元仿真控制模型.采用Web服务技术设计了柔性制造单元控制实体之间的通讯模型,结合Arena RT模犁实时控制外部应用程序的特性,构建了基于Web服务和Arena RT的仿真控制软件体系结构.在此基础上,设计并实现了一种开放式、可视化,以及对柔性制造单元实时控制的仿真集成系统.以某军工单位的机加车间为例,验证了该仿真系统的实时控制性.     

Anti-lock brake system control for buses based on fuzzy logic and a sliding-mode observer

In this paper, an anti-lock brake system (ABS) for commercial buses is proposed based on a fuzzy-logic controller and a sliding-mode observer of the vehicle speed. The brake controller generates pulse width modulated (PWM) control inputs to the solenoid valve of each brake, as a function of the estimated wheel slip ratio. PWM control inputs at the brakes significantly reduce chattering in the brake system compared with conventional on-off control inputs. The sliding-mode observer estimates the vehicle speed with measurements of wheel speed, which is then used to compute the wheel slip ratio. The effectiveness of the proposed control algorithm is validated by a series of computer simulations of bus driving, where the 14-DOF bus model is used.     

基于信息流的医疗设备柔性智能制造研究

目的 对定制化的医疗设备制造过程的特殊要点进行总结,得出医疗设备柔性智能制造过程的设计和适用于质量控制的关键要点。方法 以医疗设备的生产流程为基础,结合医疗设备行业的特点,梳理医疗设备柔性制造中的关键问题和生产控制要点,提出适用于医疗设备柔性制造的改造思路。结果 理想的柔性制造应该依托数据流互通与溯源,进而实现建模、仿真、优化与预警的智能化应用。本文得出了三个建设要点：以“机器换人”为主要内容的技术改造形成了质量控制最基本的信息流;数字化引导,实现数据的分析利用及溯源,物料的可溯源检测实现加工工艺的调整和优化;大数据系统支持,帮助缩短制造流程,避免产品缺陷和错误。结论 医疗设备的智能制造可以依托生产执行系统制造执行系统(Manufacturing Execution System, MES),从工业机器人-数据流-仿真建模的递进思路进行改造,实现柔性制造的订单可变、产能可用、物料可得的运作体系,实现产品生产全周期质量可控。     

Scheduling algorithms for a two-machine flexible manufacturing system

The flexible manufacturing system (FMS) considered in this paper is composed of two CNC machines working in series—a punching machine and a bending machine connected through rollers acting as a buffer system of finite capacity. The main difference between the present problem and the standard two-machine flow shop problem with finite intermediate capacity is precisely the buffer system, which in our problem consists of two stacks of parts supported by rollers: the first stack contains the output of the punching machine, while the second stack contains the input for the bending machine. When the second stack is empty, the first stack may be moved over. Furthermore, the capacity of each stack depends on the particular part type being processed.The FMS can manufacture a wide range of parts of different types. Processing times on the two machines are usually different so that an unbalance results in their total workload. Furthermore, whenever there is a change of the part type in production, the machines must be properly reset—that is, some tools need to be changed or repositioned.A second important difference between the present problem and the usual two-machine flow shop problem is the objective. Given a list ofp part types to be produced in known quantities, the problem considered here is how to sequence or alternate the production of the required part types so as to achieve various hierarchical targets: minimize the makespan (the total time needed to complete production) and, for instance, compress the idle periods of the machine with less workload into a few long enough intervals that could be utilized for maintenance or other reasons.Although Johnson's rule is optimal in some particular cases, the problem addressed in the paper isNP-hard in general: heuristic procedures are therefore provided.     

基于 Petri网的柔性制造系统动态优化模型

为解决柔性制造系统的动态优化调度问题,在基于扩展高级全局决策Petri网的柔性制造系统优化模型的基础上,提出了实时一优化切换控制Petri网模型。该模型在柔性制造系统发生加工设备故障、急件插入等异常情况时,自动切换并运行全局优化调度算法,并在系统允许的时间范围内,再切换返回到原有系统状态,按照新的优化结果运行。最后,以实时一优化切换控制Petri网模型与基于遗传的最小平衡算法结合为例,证实了该模型是有效的。     

基于FROFINET工业以太网的柔性制造系统的研究

柔性制造系统做为一种先进的生产方式,目前正得到越来越广泛的应用,柔性制造系统的控制网络结构及通信方式是柔性制造系统的关键技术,针对传统基于串口的网络通信方式速度慢、难于满足实时运行控制要求,而基于现场总线的柔性制造系统难于同企业的管理层集成的不足,提出了一种基于FROFINET工业以太网的网络控制结构,探讨了柔性制造系统各站点之间的通信关系以及FROFINET组件的通信,同时介绍了其组态方法。     

基于OPC技术的柔性制造系统集成平台研究

提出一种基于OPC技术的柔性制造系统集成平台,该平台利用MCGS作为OPC服务器,包括若干数控加工单元以及机械手、物料传送装置.平台集成了车间调度算法,可根据遗传算法优化出来的调度方案运行.利用ASP.NET编写平台的WEB服务器程序以实现对该平台的远程监控.该柔性制造系统平台具备较强的开放性和灵活性,能够实现可靠的信息传输.     

The adaptive Kalman filter based on fuzzy logic for inertial motion capture system

In the inertial motion capture system, the model complexity and the large amount of computation make the completion of the orientation estimation algorithm rely solely on PC. Because the data processing speed is slow, it is difficult to realize high-speed motion tracking in the embedded system. In order to further expand the application of the motion tracking technology, this paper introduces a two-step Kalman filter, which is suitable for the embedded system. The filter is composed of two sub filters, and is adaptively adjusted based on the variance matching of fuzzy logic. IMU orientation is calculated based on the filtered acceleration vector and the estimated yaw. This approach simplifies the mathematical model, reduces the matrix operations and improves the speed of computation.     

A flexible microassembly system based on hybrid manipulation scheme for manufacturing photonics components

In this paper, a flexible microassembly system based on hybrid manipulation scheme is proposed to apply to the assembly of photonics components such as lensed optical fiber ferrules and laser diode (LD) pumps. In order to achieve both high precision and dexterity in microassembly, we propose a hybrid microassembly system with sensory feedbacks of vision and force. This system consists of the distributed six degrees of freedom (DOF) micromanipulation units, the stereomicroscope, and haptic interface for the force feedback-based microassembly. A hybrid assembly method, which combines the vision-based microassembly and the scaled teleoperated microassembly with force feedback, is proposed. The feasibility of the proposed method is investigated via experimental studies for assembling micro-optoelectrical components. Experimental results show that the hybrid microassembly system is feasible for applications to the assembly of photonic components in the commercial market with better flexibility and efficiency.     

Developing a computer control system for a flexible manufacturing cell

This article focuses on the development of a computer control system for a flexible manufacturing cell. The paper outlines the various modules that are required for a computer control system and elaborates on the development of some of these modules. This is part of an ongoing research project at the University of the Witwatersrand. The aim of the project is to demonstrate the viability of flexible manufacturing systems to South African industry. Thus the main constraints of the project were cost, ease of implementation, and ease of maintainability. This necessitated the use of existing machinery and of computer systems and software that were readily available and already familiar to industry.     

基于极限学习机的复杂制造系统动态调度

为提高复杂制造系统动态调度的有效性,提出一种数据驱动的动态调度方法.采用组合式调度规则作为调度策略,通过试验设计方法对调度样本数据进行优化;采用模糊C均值聚类算法和极限学习机算法对最优样本集进行聚类和学习,得到调度模型供动态调度使用,有效地提高动态调度的精度和效率.所提方法在半导体制造Benchmark模型M IM A...     

基于GSM网络的柔性制造车间安防报警系统设计

基于GSM网络平台的柔性制造车间报警系统,集计算机技术、无线网络通信技术和测控技术于一体,实现了报警联网和远程监控管理功能[1].该系统可以实时接收远端现场情况的最新资料和报警信息,安防管理人员可以通过收到的信息及时了解前端现场的情况并进行处理.该系统结构简单、实施灵活,并节省了大量的人力和物力,提高了安全生产防范的监管力度和效率.因此研究及应用基于GSM网络平台的柔性制造车间报警系统具有非常重要的现实意义.     

Dynamic control of flexible manufacturing systems

Flexible manufacturing systems (FMSs) are a relatively new technological and organisational approach to helping companies respond to real-time marketing conditions for their production. Under a proposal of the National Bureau of Standards the FMSs are subdivided into virtual manufacturing cells in a dynamic manner, on the basis of group technology.A method of dynamic optimisation for the design of manufacturing processes, capacity balancing and checking, and also production scheduling or rescheduling in virtual manufacturing cells is described. It can be used during real-time production control in FMSs.