A Formal Model for Real-Time Automated Manufacturing System Control with Timed-MPSG

The objective of this paper is to extend the MPSC model by introducing the temporal properties to check time constraint, and do the performance analysis of the real-time shop floor controller. The MPSG (message-based part state graph) model has been developed for the execution portion of shop-floor controllers that operate in a distributed and hierarchical control environment. It is based on deterministic finite state automata and represents the execution module of shop-floor controller as a communicating finite state machine. However, there is still no consideration for handling the time in this framework. For this purpose, a formal model of Timed-MPSG processes is proposed in terms of a real-time part processing task. Furthermore, the conceptual idea, control flow algorithm and the implementation methodology of the Timed-MPSG are described with a simple example.