Douglas H. Norrie

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.

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

Abstract 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.

Multi-agent Mediator architecture for distributed manufacturing

A generic Mediator architecture for distributed task planning and coordination has been developed using multi-agent paradigms. In this approach, agents function autonomously as independent computing processes, and dynamic virtual clusters coordinate the agents activities and decision making. This coordination involves dynamically created coordination agents and resource agents concurrently. The Mediator architecture contains three levels of these coordination agents: the template mediator, the data-agent manager, and the active mediator. The template mediator is the top-level global coordinator. This agent contains both the templates and the cloning mechanism to create the successively lower-level agents. Task plans are decomposed successively into subtasks, which are allocated to dynamically created agent clusters coordinated through data-agent managers and active mediators. Coordination of agent activity takes place both among the clusters and within each cluster. The system dynamically adapts to evolving manufacturing tasks, with virtual agent clusters being created as needed, and destroyed when their tasks are completed. The mediator architecture and related mechanisms are demonstrated using an intelligent manufacturing scheduling application. Both the machines and the parts involved in this production system are considered as intelligent agents. These agents use a common language protocol based on the Knowledge Query Manipulation Language (KQML). The generic Mediator approach can be used for other distributed organizational systems beyond the intelligent manufacturing application it was originally developed for.

MetaMorph: An adaptive agent-based architecture for intelligent manufacturing

Global competition and rapidly changing customer requirements are forcing major changes in the production styles and configuration of manufacturing organizations. Traditional centralized manufacturing systems are not able to meet such requirements. This paper proposes an agent-based approach for dynamically creating and managing agent communities in such widely distributed and everchanging manufacturing environments. After reviewing the research literature, an adaptive multi-agent manufacturing system architecture called MetaMorph is presented and its main features are described. Such architecture facilitates multi-agent coordination by minimizing communication and processing overheads. Adaptation is facilitated through organizational structural change and two learning mechanisms: learning from past experiences and learning future agent interactions by simulating future dynamic, emergent behaviours. The MetaMorph architecture also addresses other specific requirements for next generation manufacturing sys...

An agent-based approach to reconfiguration of real-time distributed control systems

We describe a general approach for dynamic and intelligent reconfiguration of real-time distributed control systems that utilizes the IEC 61499 function block model. This work is central to the development of distributed intelligent control systems that are inherently adaptable and dynamically reconfigurable. The approach that is used takes advantage of distributed artificial intelligence at the planning and control levels to achieve significantly shorter up-front commissioning times as well as significantly more responsiveness to change. This approach is based on object-oriented and agent-based methods, and aims at overcoming the difficulties associated with managing real-time reconfiguration of an intelligent manufacturing system.

Bidding-based process planning and scheduling in a multi-agent system

Abstract Effective and efficient implementation of intelligent and/or agile manufacturing systems requires an enterprise level integration. The first step in this direction is to integrate design, process planning and and scheduling. This paper describes a bidding-based approach to the integration of computer-aided design, process planning and real time scheduling. The product is represented in a STEP model with detailed design and administrative information including design specifications, batch size, and due dates. Upon arrival at the manufacturing facility, the product is registered in the shop floor manager which is essentially a coordinating agent. The shop floor manager broadcasts the products requirements to the machines. The shop contains autonomous machines that have knowledge about their functionality, capabilities, tooling and schedules. Each machine has its own process planner and responds to the products request in a way that is consistent with its capabilities and capacities. When more than one machine offers certain process(es) for the same requirements, they enter into negotiation. Based on processing time, due date and cost, one of the machines wins the contract. The successful machine updates its schedule and advises the product to request raw material for processing. The concept was implemented using a multi-agent system in an object-oriented programming language. The task decomposition and planning are achieved through contract nets. Examples are included to illustrate the approach.

MetaMorph II: an agent-based architecture for distributed intelligent design and manufacturing

Agent technology derived from Distributed Artificial Intelligence is increasingly being considered for next generation computer-integrated manufacturing systems, to satisfy new requirements for increased integrability, configurability, adaptability, extendibility, agility, and reliability. This paper reviews our previous research on the application of the agent-based technology to intelligent design and manufacturing and describes the current research project MetaMorph II (an agent-based architecture for distributed intelligent design and manufacturing).

An architecture for metamorphic control of holonic manufacturing systems

Abstract Conventional centralised scan-based control systems are not suited to the evolutionary nature of holonic manufacturing systems, i.e. the form and substance of holonic systems undergo constant transformation (metamorphosis) throughout their lifetime. As a result, real-time control of such holonic systems requires a radically different approach from that of traditional unit level regulatory control systems necessitating a new system-level distributed control approach. Control systems based on this approach can termed as metamorphic control systems. The engineering of such software-centric metamorphic control systems for dynamically reconfigurable distributed multi-sensor-based holonic systems is addressed in this paper. An integrated and uniform event-driven control architecture is specified for various functional levels of the metamorphic control system. This architecture utilises the emerging International Electrotechnical Commission function block standard (IEC 61499) for industrial process measurement and control systems to specify the requisite behaviour of distributed control software components (agents).

Distributed decision-making using the contract net within a mediator architecture

Abstract Manufacturing industries are facing increasing competitive challenges in both maintaining their existing markets and improving their capability to respond efficiently to marketplace needs. New architectures are required for next generation of manufacturing systems which must be developed to meet these challenges. This paper introduces a novel approach for dynamically creating and managing agent communities or virtual clusters. These virtual clusters use Contract Net bidding for multi-agent negotiation and Mediator agents to co-ordinate their actions. The manufacturing system is thus populated by heterogeneous agents and structures of control which operate autonomously during the planning and execution periods of the manufacturing tasks.

Mediator: an intelligent information system supporting the virtual manufacturing enterprise

Mediator is an open architecture information and knowledge management system designed to provide a flexible technology to support the management of complex manufacturing activities throughout the product life cycle. A heterogeneous environment is assumed in which the sub-systems are geographically dispersed and involve different application packages, not necessarily designed to work together, multiple platforms, protocols and forms of user interface. The function of Mediator is to provide a knowledge support system for all those involved in the manufacturing process from requirements through design, engineering, production, to maintenance and recycling. It is designed to facilitate communication, compliance with constraints including physical restrictions and legal obligations, and to generally represent knowledge about any activity or subsystem relevant to the manufacturing process. This paper reports on a second-generation Mediator implementation based on World-Wide-Web protocols and browsers augmented by specialist helper and server applications.