A Novel Methodology to Deadlock Analysis and Avoidance for Automatic Control Systems Based on Petri Net

Numerous studies have utilized Petri nets for modeling, fault diagnosis, and deadlock control in manufacturing processes and systems. However, most are confined to specific subclasses of Petri nets, thus limiting their applicability. This paper extends the research scope by focusing on generalized Petri nets, analyzing system models from a novel perspective, and demonstrating the complete workflow from modeling to constraint establishment, controller integration, and deadlock avoidance. The methodology begins with an introduction to thread analysis, which involves identifying critical transitions within individual threads to locate resource cycles and minimal siphons corresponding to dead transitions, along with the presentation of a dedicated algorithm for this purpose. Next, optimal constraints are derived based on the thread analysis approach, with generalized patterns summarized for partially parameterized scenarios. Controllers are then incorporated into the system model according to the aforementioned constraints. Finally, derivative issues arising from controller integration are discussed, and pathways based on thread–circuit analysis are synthesized. The entire process described above is substantiated through illustrative case studies.