An approach for characterizing the operating modes in dynamic hybrid control architectures

Nowadays, manufacturing control system faces the challenge of featuring optimal and reactive mechanisms to respond to volatile environments. In automation domain, hybrid control architectures solve these requirements as it allows coupling predictive/proactive and reactive techniques in manufacturing operations. However, to include dynamic coupling features, it is necessary to characterize the possible new operating modes and visualize its potential when a switching is needed. This paper presents an approach to characterize the operating modes of dynamic hybrid control architectures to support the dynamic switching process. The results, obtained through a simulation in a multi agent platform of flexible manufacturing systems, showed the interest of our approach in terms of including the characterization of operating modes as decisional criteria towards a system switching.info:eu-repo/semantics/publishedVersio

A switching mechanism framework for optimal coupling of predictive scheduling and reactive control in manufacturing hybrid control architectures

Nowadays, manufacturing systems are seeking control architectures that offer efficient production performance and reactivity to disruptive events. Dynamic hybrid control architectures are a promising approach as they are not only able to switch dynamically between hierarchical, heterarchical and semi-heterarchical structures, they can also switch the level of coupling between predictive scheduling and reactive control techniques. However, few approaches address an efficient switching process in terms of structure and coupling. This paper presents a switching mechanism framework in dynamic hybrid control architectures, which exploits the advantages of hierarchical manufacturing scheduling systems and heterarchical manufacturing execution systems, and also mitigates the respective reactivity and optimality drawbacks. The main feature in this framework is that it monitors the system dynamics online and shifts between different operating modes to attain the most suitable production control strategy. The experiments were carried out in an emulation of a real manufacturing system to illustrate the benefits of including a switching mechanism in simulated scenarios. The results show that the switching mechanism improves response to disruptions in a global performance indicator as it permits to select the best alternative from several operating modes.This article was supported by COLCIENCIAS Departamento Administrativo de Ciencia, Tecnología e Innovación 10.13039/100007637 [Grant Number Convocatoria 568 Doctorados en el exterior]; Pontificia Universidad Javeriana [Grant Number Programa de Formacion de posgrados].info:eu-repo/semantics/publishedVersio

A nervousness regulator framework for dynamic hybrid control architectures

Dynamic hybrid control architectures are a powerful paradigm that addresses the challenges of achieving both performance optimality and operations reactivity in discrete systems. This approach presents a dynamic mechanism that changes the control solution subject to continuous environment changes. However, these changes might cause nervousness behaviour and the system might fail to reach a stabilized-state. This paper proposes a framework of a nervousness regulator that handles the nervousness behaviour based on the defined nervousness-state. An example of this regulator mechanism is applied to an emulation of a flexible manufacturing system located at the University of Valenciennes. The results show the need for a nervousness mechanism in dynamic hybrid control architectures and explore the idea of setting the regulator mechanism according to the nervousness behaviour state.info:eu-repo/semantics/publishedVersio

EasySched : une architecture multi-agent pour l'ordonnancement prédictif et réactif de systèmes de production de biens en fonction de l'énergie renouvelable disponible dans un contexte industrie 4.0

International audienceIndustry 4.0 is concerned with sustainable development constraints. In this context, we propose a multi-agent architecture, named EasySched, aiming at elaborating predictive and reactive scheduling as the result of a coordination between systems producing goods and systems producing renewable energy. The validation of this architecture is original, and was conducted in a completely and physically distributed way, using networked embedded systems. This validation was done on a series of instances inspired by the literature. The results showed that EasySched succeeds in adapting the production of goods according to the available renewable energyL'industrie 4.0 s'accompagne de la prise en compte de contraintes de développement durable. Dans ce contexte, nous proposons une architecture multi-agent pour l'ordonnancement prédictif et réactif coordonné entre des systèmes de production de biens et des systèmes de production d'énergie renouvelable, appelée EasySched. La validation de cette architecture est originale, elle est menée de manière complètement et physiquement distribuée en utilisant des systèmes embarqués en réseau. Cette validation est menée sur une série d'instances inspirées de la littérature. Les résultats montrent que les mécanismes proposés permettent d'adapter la production selon l'énergie renouvelable disponible

Pollux: a dynamic hybrid control architecture for flexible job shop systems

Nowadays, manufacturing control systems can respond more effectively to exigent market requirements and real-time demands. Indeed, they take advantage of changing their structural and behavioural arrangements to tailor the control solution from a diverse set of feasible configurations. However, the challenge of this approach is to determine efficient mechanisms that dynamically optimise the configuration between different architectures. This paper presents a dynamic hybrid control architecture that integrates a switching mechanism to control changes at both structural and behavioural level. The switching mechanism is based on a genetic algorithm and strives to find the most suitable operating mode of the architecture with regard to optimality and reactivity. The proposed approach was tested in a real flexible job shop to demonstrate the applicability and efficiency of including an optimisation algorithm in the switching process of a dynamic hybrid control architecture.This work was supported by the Colombian scholarship programme of department of science – COLCIENCIAS under grant ‘Convocatoria 568 – Doctorados en el exterior’ and the Pontificia Universidad Javeriana under grant ‘Programa de Formacion de posgrados del Profesor Javeriano’.info:eu-repo/semantics/publishedVersio

Governance mechanism in control architectures for Flexible Manufacturing Systems

Manufacturing systems, and specifically Flexible Manufacturing Systems (FMS), face the challenge of accomplish global optimal performance and reactiveness at dynamic manufacturing environments. For this reason, manufacturing control systems must incorporate mechanisms that support dynamic custom-build responses. This paper introduces a framework that includes a governance mechanism in control system architectures that dynamically steers the autonomy of decision-making between predictive and reactive approaches. Results from experiments led in simulation show that it is worth studying in depth a governance mechanism that tailors the structure and/or behaviour of a manufacturing control system and, at the same time, potentiate the reactivity required in manufacturing operations.info:eu-repo/semantics/publishedVersio

Benchmarking flexible job-shop scheduling and control systems

Benchmarking is comparing the output of different systems for a given set of input data in order to improve the system’s performance. Faced with the lack of realistic and operational benchmarks that can be used for testing optimization methods and control systems in flexible systems, this paper proposes a benchmark system based on a real production cell. A three-step method is presented: data preparation, experimentation, and reporting. This benchmark allows the evaluation of static optimization performances using traditional operation research tools and the evaluation of control system's robustness faced with unexpected events

A comparison study of heuristics for solving the 2D guillotine strip and bin packing problems

International audienceIn this paper we consider the two dimensional strip and bin packing problem with guillotine cuts. The problem consists in packing a set of rectangular items on one strip of width W and infinite height or in bins of width W and height H. The items packed without overlapping, must be extracted by a series of cuts that go from one edge to the opposite edge (guillotine constraint). To solve this problem, we proposed tow heuristics, BSHF (best shelf heuristic filling) and NSHF (non-shelf heuristic filling). We compare the two heuristics with other heuristics from the literature. Computational results show that the two algorithms are complementary and they outperform the other algorithms in most of the instances

An Exact Method for the 2D Guillotine Strip Packing Problem

We consider the two-dimensional strip packing problem with guillotine cuts. The problem consists in packing a set of rectangular items on one strip of width W and infinite height. The items packed without overlapping must be extracted by a series of cuts that go from one edge to the opposite edge (guillotine constraint). To solve this problem, we use a dichotomic algorithm that uses a lower bound, an upper bound, and a feasibility test algorithm. The lower bound is based on solving a linear program by introducing new valid inequalities. A new heuristic is used to compute the upper bound. Computational results show that the dichotomic algorithm, using the new bounds, gives good results compared to existing methods