Automatic generation of control solution for resource allocation using Petri net model

Abstract

Geração automática da solução de controle para alocação de recursos utilizando redes de Petri RESUMO O sistema fl exível de manufatura (FMS fl exible manufacturing system) executa múltiplos processos simultaneamente que utilizam um conjunto limitado de recursos. Estes processos podem fi car permanentemente bloqueados em função da seqüência de atividades, isto é, o compartilhamento de um conjunto fi nito de recursos pode levar o sistema a um estado de autotravamento. O FMS pode ser visto como pertencente a uma classe de sistema a eventos discretos, onde não é possível determinar quando um evento ocorre e com isto a seqüência de eventos fi ca indefi nida. Este tipo de sistema pode ser modelado através de rede de Petri e assim explora-se esta técnica para desenvolver uma solução para o problema de autotravamento considerando o indeterminismo do FMS. O objetivo é introduzir uma abordagem algorítmica para a implementação de uma ferramenta computacional baseada na especifi cação funcional do FMS e que automatize a geração de uma estratégia de controle para a utilização de recursos e de regras para evitar o autotravamento. PALAVRAS-CHAVESistema fl exível de produção, autotravamento de processos, rede de Petri, controle de sistemas de produção, alocação de recursos. ABSTRACT The fl exible manufacturing system (FMS) executes multiple processes simultaneously using a limited set of resources. These processes can be blocked permanently due to the sequence of the activities, i.e., the processes sharing a fi nite set of resources may eventually lead to a deadlock state. The FMS belongs to the class of discrete event systems where it is not possible to determine when an event will occur and the sequence of events becomes undefi ned. Such systems can be modeled using Petri net, and this work presents a method that solves the deadlock problem considering the indeterminism of FMSs. The goal of this work is to introduce an algorithmic approach, which allows the implementation of a computer program based on FMS functional specifi cation. The proposal is to automate the generation of the control strategy for resource utilization and the rules to avoid the deadlock situation. KEY WORDSFlexible manufacturing system, deadlock avoidance, Petri net, production system control, resource allocation. Automatic generation of control solution for resource allocation using Petri net modelFrancisco Yastami Nakamoto Centro Universitário Fundação Santo André Paulo Eigi Miyagi EPUSP Diolino José dos Santos Filho EPUSP 9 Nakamoto, F. Y.; Miyagi, P. E.; Filho, D. J. S. Automatic generation of control solution for resource allocation using Petri Net Model.

Modelling and Control of Resource Allocation Systems within Discrete Event Systems by Means of Petri Nets -- Part 1: Invariants, Siphons and Traps in Deadlock Avoidance

“…Of course, since that time the deadlock theory, and especially the deadlock avoidance one, has been intensively developed -see e.g. [46,78,79,80,81,75,74,73,82,86,87] and especially [63,8,25,55,56,57,59,62,64,28,29,30,31,32,33,34,35,36,37,38,39,40,92,93,94,91,88,89,65,66,67,68,69,58,60,61,47,48,49,50,51,…”

Manufacturing operational management modeling using interpreted Petri nets

“…The greatest challenge is the planning and control that guarantee of process flows and results in production established by production planning (Santos, 2000). Another important aspect is the productivity of Flexible Productive Systems it is related to the efficient use of available resources (Nakamoto et al, 2009;Asato, 2015;Kubo et al, 2016). According to Nakamoto et al (2009), the imposition of a desired dynamic behavior to the system requires, from the point of view of control a single process, the guarantee of the sequential execution of all the activities of the controlled process, being this sufficient.…”

“…Another important aspect is the productivity of Flexible Productive Systems it is related to the efficient use of available resources (Nakamoto et al, 2009;Asato, 2015;Kubo et al, 2016). According to Nakamoto et al (2009), the imposition of a desired dynamic behavior to the system requires, from the point of view of control a single process, the guarantee of the sequential execution of all the activities of the controlled process, being this sufficient. But when viewed from the perspective of the overall process of the system, that is, when there are multiple processes in execution, the sequencing of process activities is lost for sharing of resources and / or process information.…”

“…The objective of the present work is to present a proposal for modeling the objects in level 3 of the ANSI / ISA S95 standard (ISA, 2013) using a methodology of control systems applied in the modeling of control of flexible productive systems (Miyagi, 1996;Santos, 2000;Matsusaki, 2004;Nakamoto et al, 2009;Asato, 2015;Kubo et al, 2016), which results in the modeling in interpreted Petri nets (Peterson, 1981;Reisig, 1985;Murata, 1989).…”

Simulations and fuzzy systems for resource reallocation

“…Once these results are available, the patient must undergo a follow-up consultation, with a service time that follows a Normal (15,5) for gynecology and Normal(10,5) for traumatology. The resources needed to carry out each consultation are an examination room and a doctor in each specialty.…”