Design of Safety Petri Net Controllers for Deadlock Prevention at a Class of Road Intersections

This paper mainly addresses the issue of designing safety Petri net-based controllers to prevent vehicle flow deadlocks at intersections. The designed controller can monitor the flow of vehicles at an intersection and guide them to pass an intersection safely without causing deadlocks. This study begins by investigating the intersection deadlock scenarios, analyzing the physical size of the “right-of-way” cells with the discretization of the interior area of an intersection, and developing the intersection initial Petri net (PN) model based on simple sequential processes with resources (S3PR). Then, based on the initial PN model, we propose a deadlock prevention strategy for controller design to control the vehicle flows to ensure that the vehicle flows in different directions do not result in deadlocks. Finally, the effectiveness of the proposed strategy is illustrated by examples and theoretical proof. This study contributes to the advancement of the state-of-the-art in the design of safety controllers for self-driving vehicles passing through intersections.