From product specification to manufacturing control

Abstract

Flexible Manufacturing Systems (FMSs) are complex systems with machines that execute thousands of operation types with complex interactions. Three kinds of problems have to be solved: product specifications, production scheduling and the control the FMS to correctly manufacture the desired products. Wrong control signals can lead to scraps instead of the desired products or often to deadlocks. Current research solves the FMS problems of the wood industry. The production process is considered a Discrete Event System (DES) that can be modeled by Delay Time Petri Nets (DTPN). The control system is hierarchical centralized modeled by Time Petri Net (TPN). Besides the usual textual description of the product specification, the UML (Unified Modeling Language) class diagrams and a formal language, called here Time Petri Net based Language (TPNL), are used. The FMS structure and its capabilities are specified by UML class diagram and DTPN. Using these specifications some examples of the control system were conceived using TPN and TPNL.