Cyrille Pach

ORCA-FMS: a dynamic architecture for the optimized and reactive control of flexible manufacturing scheduling

Abstract Reactive and effective hybrid manufacturing control architectures, combining hierarchy and heterarchy adapted to the current constraints of the industrial market and its environment were created. In this article, a new generic hybrid control architecture called ORCA (dynamic Architecture for an Optimized and Reactive Control) is first proposed. This hybrid architecture is able to dynamically and partially switch between a hierarchical predictive architecture and a heterarchical reactive architecture, if an event forbidding the planned behavior to be followed occurs. In this article, this architecture was applied to a Flexible Manufacturing System (FMS) problem and denoted ORCA-FMS. ORCA-FMS was tested on an existing manufacturing cell with simulations and real experiments to prove the applicability and the effectiveness of this kind of hybrid architecture in an industrial environment.

Reactive and energy-aware scheduling of flexible manufacturing systems using potential fields

This paper presents a reactive scheduling approach for flexible manufacturing systems, which integrates the overall energy consumption of the production. This work is justified by the growing needs of manufacturers for energy-aware control, due to new important environmental criteria, which holds true in the context of high reactivity. It makes production hard to predict. The proposed reactive scheduling model is based on potential fields. In this model, resources that sense the intentions from products are able to switch to standby mode to avoid useless energy consumption and emit fields to attract products. Simulations are provided, featuring three indicators: makespan, overall energy consumption and the number of resource switches. Real experiments were carried out to illustrate the feasibility of the approach on a real system and validate the simulation results.

The control of myopic behavior in semi-heterarchical production systems: A holonic framework

Heterarchical control architectures are essentially founded on cooperation and full local autonomy, resulting in high reactivity, no master/slave relationships and local information retention. Consequently, these architectures experience myopic decision-making, bringing entities towards local optimality rather than the systems overall performance. Although this issue has been identified as an important problem within heterarchical control architectures, it has not been formally studied. The aim of this paper is to identify the dimensions of myopic behavior and propose mechanisms to control this behavior. This study focuses on myopic behavior found in manufacturing control. For this particular study, we propose a holonic framework and a holonic organization that integrates specific mechanisms to control the temporal and social myopia. Our proposal was validated using simulations designed for solving the allocation problem in flexible manufacturing systems. These simulations were conducted to show the improvement by integrating the new mechanisms. These simulation results indicate that the myopic control mechanisms achieve better performance than the reactive strategies, because not only they introduce a planning horizon, but also because they balance local and global objectives, seeking a consensus.

An approach for temporal myopia reduction in Heterarchical Control Architectures

This paper presents a model that aims at diminishing the impact of temporal myopia in Heterarchical Control Architectures (HeCA) of Flexible Manufacturing System (FMS). This model is based on a “switching architecture”, based upon the concept of intelligent reactive products. A virtual layer hosts Product Agents having the objective of preserving global performance, while a physical layer congregates physical products trying to follow the prescribed behavior, unless they sense a change of conditions. The idea is to empower autonomy while achieving an overall good global performance. For experimental purposes, this approach has been deployed at the AIP-PRIMECA center at University of Valenciennes, France and some results are presented.

Myopic Behaviour in Holonic Multiagent Systems for Distributed Control of FMS

Multi-Agent Systems (MAS) are particularly adapted to deal with dynamic distributed environments and are typically used to manage business workflows or data flows in manufacturing systems. But, the lack of a global view and reference of the whole system by the low-level and physical parts, to actually guarantee optimal decision-making had been labelled by some researchers as ‘Myopia’. Thus, this paper intents to identify some Myopias, involved in a decentralised management of production systems. A HoloMAS (HolonicMultiAgent System), whose elementary parts show signs of myopia, is defined; and we validated our HoloMAS proposal using simulations and through a real implementation on a flexible assembly cell in our university lab.

Routing Management in Physical Internet Crossdocking Hubs: Study of Grouping Strategies for Truck Loading

The aim of the innovative Physical Internet (PI) paradigm-shifting initiative is to reverse the unsustainability situation existing in current logistic systems. In the Physical Internet, the efficient management of crossdocking hubs is a key enabler of quick and synchronized transfer of containers across interconnected logistics networks. The paper focuses on the distributed control of truck loading protocols in a rail-road crossdocking hub. It proposes grouping strategies for truck loading based on the exploitation of active containers. The grouping approach, the simulation platform and the obtained results are successively detailed.

Roles-based MAS applied to the control of intelligent products in FMS

This paper presents a formalization of a solution to control the myopia and its impact on performances of Flexible Manufacturing Systems (FMS) controlled by intelligent products. The model is based on the concept of the functional roles in Multi-Agent Systems which is described through a brief state of the art. Then this concept is applied to the control of a FMS. Entities, their roles, their knowledge and behaviors are explained in details. Finally, the proposed solution is implemented at the AIP-PRIMECA FMS of Valenciennes and some experimental results are given.

Effective, Energy-Aware Control of a Production System: A Potential Fields Approach

This paper presents a potential fields-based approach for the efficient and effective control of Flexible Manufacturing Systems using intelligent products. This reactive approach solves the scheduling problem in a dynamic context whilst taking into consideration energy consumption. A real case study simulation is provided, looking at indicators related to effectiveness such as makespan, and efficiency such as overall energy consumption. The implementation of the intelligent products in real conditions is also proposed to validate the simulations.

Instantiation of the Open-Control concept in FMS based on potential fields

Flexible Manufacturing Systems (FMS) must continually deal with the increasing complexity of product requirements as well as mounting pressure to decrease costs and increase control system adaptability to environmental changes. In this context, we have proposed the “Open-Control” concept. This generic concept includes both the traditional explicit control and an innovative type of control, called implicit control, which allows system entities to be controlled indirectly via an Optimization Mechanism (OM). An implementation was carried out on a real FMS using potential fields (PF). This implementation is presented, and our initial results are reported and discussed, pointing out the advantages of considering implicit control, in addition to traditional explicit control.