Recent Advances in the Modeling, Schedulipjg and Control of Flexible Automation

This paper initially discusses the state-of-the-art and the current limitations in the modeling, scheduling and control of flexible automation. To model flexible automation, it is argued that the simulation tools must provide enhanced capabilities to consider both controller interactions and the flow of resources that support production. It is also demonstrated that scheduling and control must be considered concurrently in real-time to effectively manage flexible manufacturing systems (FMSs). The complexity of the modem FMS further requires that the integrated scheduling and control function must be distributed among several coordinators with the system. The second part of the paper presents several research developments pertaining to the modeling, scheduling and control of flexible automation including: a Recursive, Object-Oriented Control Hierarchy for the integrated distribution of scheduling and control; a Hierarchical ObjectOriented Programmable Logic Simulator €or the detailed modeling of FMSs; and a Hierarchical System Coordinator for implementing real-time scheduling and control. A physical emulator for an FMS which is being constructed is discussed as the example application in this presentation. Finally, the futureresearch plan and theeducational program based upon the developments is outlined.