Didier Anciaux

Shop-floor control: A multi-agents approach

This paper proposes a novel approach to shop-floor control. In particular, its aim is to solve dynamic production control problems in real-time (due to workstation breakdowns, urgent orders, etc), to automate as much as possible the control process in order to adapt the system to production plan modifications and to rationalize decision-making by a means of strong hierarchical structure. To achieve this, the system is based on a twofold hybrid multi-agent platform. First, control is hierarchically distributed and decision-making is centralized, thus this type of system mediates between centralized and hierarchical architecture types. Centralization allows us to avoid the competition between agents to solve a problem, and hierarchical distribution allows each agent to take care of only one product. Thus, significant gains in terms of response times and reactivity capabilities are obtained thanks to this hybrid approach.

SYROCO: A novel multi-agent shop-floor control system

Shop-floor control is known to be a hard problem because it must supervise manufacturing operations execution according to plans, respect delays and deal with real-time system perturbations. Modern shop-floor control systems must be reactive, i.e., be able to quickly and timely react to perturbations, be they external or internal perturbations to the system to be controlled.This paper proposes a novel approach to shop-floor control. Especially, its aim is to solve dynamic production control problems in real-time (due to workstation breakdowns, urgent orders...), to automate as much as possible the control process in order to adapt the system to production plan modifications and to rationalize decision-making by a means of strong hierarchical structure.To achieve this, the system is based on a two-fold hybrid multi-agent platform. First, control is hierarchically distributed and decision-making is centralized, thus this type of system mediates between centralized and hierarchical architecture types. Centralization allows to avoid the competition between agents for solving a problem while hierarchical distribution allows each agent to take care of only one product. Second, a complete schedule is completed at the beginning of the process, but it can be partially (or totally) modified during the process. Thus, significant gains in terms of response times and reactivity capabilities are obtained thanks to this hybrid approach.

Reactive Shop-Floor Control with a Multi-Agent System

Abstract The paper presents a reactive shop-floor control strategy. It is based on a hierarchical and multi-agent approach. Agents do not cooperate directly but communicate to one another only via a supervisor. The supervisor is a high granularity agent. Communications between the different agents is implemented by means of the Berkeley sockets on the TCP/lP protocol. The control system is called SYROCO.