MODELING WITH COLORED TIMED OBJECT-ORIENTED PETRI NETS FOR AUTOMATED MANUFACTURING SYSTEMS

This paper presents a new paradigm, called CTOPN (colored timed object-oriented Petri net), to model an automated manufacturing system (AMS). A CTOPN model consists of four major characteristics: (1) the dynamic behavior of an AMS is represented from an object-oriented perspective, (2) the input/output transform functions, colored tokens and the associated time-delay attributes are employed to model the characteristics of material flow (e.g., part routing) and time constraints in an AMS, (3) the control logic/dynamic behavior of an AMS may be explicitly analyzed, (4) an integrated and consistent environment is provided to simultaneously model, schedule and control an AMS. In this paper, we will introduce the definition of a CTOPN, the procedure of developing a CTOPN model, a deadlock detection algorithm, and applications of the CTOPN approach in scheduling and controlling an AMS.