Expert system to match robots and to synchronize their operations to pick and place large parts

The operation of pick and place large parts is a very common operation on the manufacturing floor. The efficiency of the pick and place operation affects the efficiency of the entire manufacturing floor. Large parts in terms of this research are parts which must be transported by two robots.This paper concludes the development of an expert system and a numerical simulation to assign two available robots to perform the pick and place operations of large parts.The developed expert system consists of a knowledge-base structured in interrelated frames to define large manufacturing systems and an inference-engine to perform the robots matching and their performances monitoring. Matching robots considerations can not be performed by numerical algorithms in real time systems, because they are major computation time consumers. Therefore, unmatched robots can be assigned by the numerical algorithms to perform inefficient pick and place operations. The expert system and the numerical simulation were programmed, and many computer runs were performed to explore the efficiency of the two systems in a large variety of manufacturing systems.The achieved results show that the expert system has no advantage in assigning matched robots to perform the pick and place operations in systems characterized by very short machine process times (0.5 moment to 1 moment). If such short machine process times are relevant, the knowledge-base is updated very frequently, and the inference-engine reasoning processes can not be initiated. For longer machine process times, the frequency of knowledge-base changes is reduced, and the inference-engine reasoning processes can be initiated without delays. Therefore, the advantages of the expert system become significant if machine process times are extended.     

Electromagnetic modular Smart Surface architecture and control in a microfactory context

This paper presents an electromagnetic conveyance system called electromagnetic modular Smart Surface (emSS) permitting to move pallets on a planar surface in a microfactory context. The proposed surface concept allows flexibility in reconfiguring the system layout along with product routing. The possibilities of accurate positioning of the moving pallet and controlling multiple pallets on the surface make the emSS suitable for reconfigurable and flexible manufacturing systems. However, the emSS control needs to be robust and scalable to adapt the changes in manufacturing systems. A framework is therefore defined to monitor and control the emSS by simulation or in-line. It allows to define product routing on the emSS by satisfying numerous requirements such as reduction in energy consumption, collision avoidance, etc., and to minimize the human interventions by changing product routing when emSS component failures occur. A first experiment realized on an emSS prototype, allowed to compare two paths strategies regarding cost function linked to energy consumption and velocities. Two other studies exploit the emSS modeling in terms of pallet path generation and simulation of collision avoidance.     

面向对象Petri网在柔性贴装系统仿真中的应用

Petri网十分适合分析、设计柔性制造系统。在Petri网基础上引入面向对象(OO)技术,采用面向对象Petri网(OPN),建立了一个PCB元件柔性贴装系统的完整的OPN模型。并利用对象之间的消息传递技术实现了两个共享工作区和物料区的机械手的无冲突工作,为其它复杂的多机械手柔性装配系统的建模提供了数学和图形工具。     

A foundation for a knowledge-base computer integrated manufacturing system

The true potential of a CIM system cannot as yet be fully realised. A further requirement is for a device which can extract manufacturing information from the outset. The main aim of the research described in this paper is to develop a knowledge-base system for extracting such information and to promote a coming together of design and manufacture. The major goal must be to enable industry to manufacture without manual intervention. A prototype knowledge-base system called HOLDEX described in this paper is an implementation that relies on combining the advantages of existing technology such as AI, CAD representation schemes, advanced manufacturing systems, man-machine interface and most importantly the encapsulated knowledge of a manufacturing engineer. The aim of the prototype system is to encourage a workpiece designer towards manufacturing standards and to assist him in the use of a general purpose CAD package. One benefit to be obtained from providing such assistance is to facilitate the ease of extracting manufacturing information. The scope of the extracted information includes the detailed specification of a set of cutting tools, the recognition of a list of required activities prior to a machining operation, the recommendation of the appropriate machine tool and the automated design of fixtures.     

An agent-based approach for e-manufacturing and supply chain integration

A major problem facing manufacturing organisations is how to provide efficient and cost-effective responses to the unpredictable changes taking place in a global market. This problem is made difficult by the complexity of supply chain networks coupled with the complexity of individual manufacturing systems within supply chains. Current systems such as manufacturing execution systems (MES), supply chain management (SCM) systems and enterprise resource planning (ERP) systems do not provide adequate facilities for addressing this problem. This paper presents an approach that would enable manufacturing organisations to dynamically and cost-effectively integrate, optimise, configure, simulate, restructure and control not only their own manufacturing systems but also their supply networks, in a co-ordinated manner to cope with the dynamic changes occurring in a global market. This is realised by a synergy of two emerging manufacturing concepts: Agent-based agile manufacturing systems and e-manufacturing. The concept is to represent a complex manufacturing system and its supply network with an agent-based modelling and simulation architecture and to dynamically generate alternative scenarios with respect to planning, scheduling, configuration and restructure of both the manufacturing system and its supply network based on the coordinated interactions amongst agents.     

A stochastic model for the analysis of a two-machine flexible manufacturing cell

This paper presents a stochastic model to determine the performance of a flexible manufacturing cell (FMC) under variable operational conditions, including random machining times, random loading and unloading times, and random pallet transfer times. The FMC under study consists of two machines, pallet handling system, and a loading/unloading robot. After delivering the blanks by the pallet to the cell, the robot loads the first machine followed by the second. Unloading of a part starts with the machine that finishes its part first, followed by the next machine. When the machining of all parts on the pallet is completed, the handling system moves the pallet with finished parts out and brings in a new pallet with blanks. A model with these characteristics turns out to be a Markov chain with a transition matrix of size 5n+3, where n is the number of parts on the pallet. In this paper, we present exact numerical solutions and economic analysis to evaluate FMC systems, to determine optimal pallet capacity and robot speed that minimize total FMC cost per unit of production.     

Applications of agent-based systems in intelligent manufacturing: An updated review

Agent technology has been recognized as a promising paradigm for next generation manufacturing systems. Researchers have attempted to apply agent technology to manufacturing enterprise integration, enterprise collaboration (including supply chain management and virtual enterprises), manufacturing process planning and scheduling, shop floor control, and to holonic manufacturing as an implementation methodology. This paper provides an update review on the recent achievements in these areas, and discusses some key issues in implementing agent-based manufacturing systems such as agent encapsulation, agent organization, agent coordination and negotiation, system dynamics, learning, optimization, security and privacy, tools and standards.     

柔性制造系统的托盘优化

本文讨论Job-shop型柔性制造系统的托盘优化问题,给出了求最小托盘数的算法,把托 盘优化问题化成了求解线性整数规划问题.     

基于混杂系统理论的制造系统仿真

根据制造系统连续事件与离散事件并存的特点,提出一种制造系统半实物仿真方法,设计连续事件和离散事件并存时仿真系统的时间推进机制。在Arena环境中实现对离散事件系统的建模,在Labview环境中实现特定连续变量事件的半实物仿真。设计并实现离散事件系统与连续事件的接口连接。仿真实验结果表明,该系统能较好地反映出整个制造系统的混杂特性,为混杂制造系统的仿真提供一种新的思路。     

Agent-Based Systems for Intelligent Manufacturing: A State-of-the-Art Survey

Agent technology has been considered as an important approach for developing distributed intelligent manufacturing systems. A number of researchers have attempted to apply agent technology to manufacturing enterprise integration, supply chain management, manufacturing planning, scheduling and control, materials handling, and holonic manufacturing systems. This paper gives a brief survey of some related projects in this area, and discusses some key issues in developing agent-based manufacturing systems such as agent technology for enterprise integration and supply chain management, agent encapsulation, system architectures, dynamic system reconfiguration, learning, design and manufacturability assessments, distributed dynamic scheduling, integration of planning and scheduling, concurrent scheduling and execution, factory control structures, potential tools and standards for developing agent-based manufacturing systems. An extensive annotated bibliography is provided.     

An intelligent simulation environment for manufacturing systems

The manufacturing field is an area where the application of simulation is an essential tool for validating methods and architectures before applying them on the factory floor. Despite the fact that there are a great number of simulation tools, most of them do not take into account the specific requirements of the “new manufacturing era” such as distributed organization, interoperability, cooperation, scalability, fault tolerance and agility. On the other hand, Multiagent System technology has demonstrated its utility in manufacturing system modeling and implementation. Agenthood features such as proactivity, reactivity, and sociability may also be useful for associating them with the specific simulation needs of the new changing requirements for manufacturing systems. In this paper, an Agent-supported Simulation Environment for intelligent manufacturing systems is presented. The different roles that are played by the agents of the simulation environment are defined taking into account the specific dynamic features in manufacturing simulation and the requirements of the new manufacturing era. Moreover, the interaction and cooperation scenarios among these agents are specified to facilitate manufacturing simulation in an appropriate and flexible way. A detailed evaluation study, with regards to the new manufacturing era requirements, demonstrates the advantages of the proposed approach over current state-of-the-art proposals.     

Maintenance scheduling and production control of multiple-machine manufacturing systems

This paper deals with the production and preventive maintenance control problem for a multiple-machine manufacturing system. The objective of such a problem is to find the production and preventive maintenance rates for the machines so as to minimize the total cost of inventory/backlog, repair and preventive maintenance. A two-level hierarchical control model is presented, and the structure of the control policy for both identical and non-identical manufacturing systems is described using parameters, referred to here as input factors. By combining analytical formalism with simulation-based statistical tools such as experimental design and response surface methodology, an approximation of the optimal control policies and values of input factors are determined. The results obtained extend those available in existing literature to cover non-identical machine manufacturing systems. A numerical example and a sensitivity analysis are presented in order to illustrate the robustness of the proposed approach. The extension of the proposed production and preventive maintenance policies to cover large systems (multiple machines, multiple products) is discussed.     

PCAAD—an object-oriented expert system for assembly of printed circuit boards

Abstract: Electronics manufacturing is the fastest growing segment of the manufacturing domain today. The rapid change in printed circuit board manufacturing has been possible with the induction of surface-mounted components and robotic assembly. The high density packaging capability of surface-mounted technology has contributed enormously to the development of new trends in printed circuit board manufacturing.
PCAAD—Printed Circuit Board Assembly Advisor—is an expert system developed to capture this new technology and its interaction with the existing through-hole-mounting technology. In building the system, rules and guidelines pertaining to assembly are formulated and incorporated into the knowledge-base. The system is built on an object-oriented paradigm. The object-oriented approach, Smalltalk-80, the object-oriented language and the hierarchical rule structure paradigm are briefly discussed. A rating system is also introduced to rank various assembly designs. PCAAD can advise whether or not to proceed with assembly with a particular assembly design, and suggests assembly modification at the early stage of design to eliminate the assembly problems in the later phase of board production.     

网络化制造集成平台服务导航系统研究与实现

提出了一种基于网络化制造集成平台，以流程为中心的服务导航系统框架，设计并实现了系统主要组件，包括事务过程分析处理器、工作流执行处理器、结果文件管理器的核心算法。克服了传统紧密耦合软件开发模式、点对点集成模式和以程序为中心的导航系统的缺陷。解决了网络化制造中制造资源信息和潜在合作伙伴的搜寻问题，增强了网络化制造系统的柔性和敏捷响应能力。     

基于TMS320DM6446的数字电影放映系统设计

在以数字多媒体处理器TMS320DM6446为核心的硬件平台上,采用达芬奇技术提出了一种新型数字电影放映系统的设计方案,并提出了应用达芬奇处理器开发数字视频产品的一般方法。该方案充分利用了达芬奇处理器高效性与编程灵活性的特点,通过使用达芬奇技术提供的系统组件和开发工具,极大地简化了数字电影放映系统软件开发的复杂性。     

Development and Applications of Holonic Manufacturing Systems: A Survey

This paper surveys the literature in the holonic manufacturing systems area in an attempt to bring together the key issues in the development and applications of holonic systems. A brief introduction presents the characteristics of today’s manufacturing environment and the requirements for next generation manufacturing systems. Then, starting with considerations about the origins of the holonic concept and its first applications in manufacturing, the paper presents the advances made in applying the holonic concept to manufacturing systems area. Several considerations for the development of holonic manufacturing systems and specific holonic system requirements are discussed. As holonic concept is considered a solution for next generation manufacturing systems, there is a significant number of applications and implementations of the holonic concept in manufacturing systems domain. The most important and relevant approaches developed so far are presented. Finally, a short conclusion and future research directions in the area are provided     

A conceptual framework for agent-based agile manufacturing cells

Abstract. Agile manufacturing techniques are perceived as the manufacturing systems of the future. Agile manufacturing cells are dynamic and reconfigurable and the modelling of the manufacturing cells and its interaction mechanism is critical to its successful use. This paper deals with the architecture and cooperation mechanism of web‐based agile manufacturing cells. Based on an analysis of structure and organization requirements of agile manufacturing cells and a comparison of three basic architectures of manufacturing systems, the quasi‐heterarchical architecture is used for the agile manufacturing cell. Functional layers are defined in this architecture to make the cell's control system reconfigurable and reusable. Agent technology is adopted for implementation of each layer's functions to establish an agent‐based model of agile manufacturing cells. Four types of agents including cooperation agent, job management agent, resource broker agent, and resource control agent are defined, and their functions discussed. Finally, a real time interaction mechanism of the agents is presented by considering the activities during the agents’ cooperation in an agile manufacturing cell.     

Intelligent Control Paradigm for Dynamic Discrete Event System Simulation

Simulation based control of discrete event systems has been a potential approach to support decision-making in the manufacturing scenario. In this paper, a knowledge intensive simulation modelling approach for a discrete even system is investigated. Based on the proposed simulation model, a robust control mechanism is presented that is believed to add significant value to discrete event dynamic system. The algorithm utilises neural network feedforward control plus robust proportional derivative feedback control to achieve control performance and output stability. The novel simulation approach, as well as the proposed controller, is implemented in an Extend TM environment and the effectiveness and usefulness of the proposed controller are verified, industrially, in the hard disk drive assembly process, a significant component of the Singapore manufacturing economy.     

可重构制造系统的可重构控制器

可重构控制器是可重构制造系统的重要组成部分之一。该文提出了可重构控制器的体系结构。分析了实现可重构制造系统的可重构控制的方法。仿真研究表明可重构控制是实现可重构制造系统控制系统可重构的有效方法。