Research

year 1992 
author Jonghun Park 
Keyword Flexible manufacturing system (FMS); Hierarchical control; Event-driven control; On-line operational control 
Abstract A two-level hierarchical scheme for event-driven operational control of FMSs is presented in this research. Some dispatchability conditions are investigated and new concepts such as task status and operations activity class (OAC) are devised to efficiently model and control various operational activities in FMSs. An off-line loading sequence generation algorithm for machining and assembly subsystems is used in the first level of hierarchy. In the second level, three control subsystems (loading control, dispatching control, and material handling control) that constitute event-driven on-line operational control system, are proposed. Salient features of the proposed approach include such considerations as alternative routings, concurrent usage of multiple types of resources, heterogeneous types of operations, blocking, starving and system deadlock, and failure-prone resources. The proposed hierarchical, event-driven operational control system operates in the real-world FMS. 
c MS 

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