Task Control of Intelligent Transportation Vehicles in Manufacturing Systems

Manufacturing Systems (MS) can be identified with discrete-item production. Actually, many of these systems conciliate high-volume production with crescent level of flexibility. Basically, MS is composed of Production Units (PU) and each PU is a set of machines, robots and others devices that produce items which are part of the final product. PUs have applied control strategies to integrate Automated Guided Vehicle (AGVs). However new technology is necessary to promote the flow of a high volume and a variety of items between the PUs. Therefore, it is essential to use the concept of Intelligent Transportation Vehicles System (IVTs) to transport all of the items that compose final products of MS. This work proposes distributed collaborative control architecture for MS with IVTs. The flow of items between the PUs of the MS can be treated as a problem of resource allocation control where the resources are the PUs and the IVTs are responsible for transport activities. Thus, it is necessary to model the global process to generate the rules for deadlock avoidance: to determine the rules that use Resource Allocation Graphs and to model the control used in graphs derived from Petri nets. The aim result is a standard model for IVT assignment. The difference in this approach is the isomorphism of models that represent productive activities and transport activities which are essential for maintenance and reusability in accordance with the dynamic products of the life cycle.

Keywords: Deadlock Avoidance, Distributed Collaborative Control, Intelligent Transportation Vehicles, Petri nets, Resource Allocation Graphs.