Control logic generation for machining systems using Petri net formalism

The logic controller for a machining system is a discrete event supervisory system. In high volume transfer lines, it consists of three control modes: auto, hand, and manual. A logic controller can achieve the goal of a machining system by its control logic. The paper addresses a formal Petri net representation of the control logic and its implementation. The control logic is represented by two Petri net models: one for the mode decision control logic and the other for the sequence control logic. Because the Petri net models are live, safe, and reversible, the actual logic control program can be generated directly from the Petri net models by using IEC1131-3 programming languages.