AGVs Collision and Deadlock Handling Based on Structural Online Control Policy: A Case Study in a Square Topology

Abstract

Based on the novel structural online control policy (SOCP) deadlock handling method presented in our previous work, we have shown that for a specific group of use cases it is possible to relax the requirements of the method, providing an improvement in its performance. In the present work, a new type of deadlock-free zone was introduced which enabled the method to improve its efficiency for both bidirectional as well as unidirectional and mixed path systems. For bidirectional systems, a beneficial outcome was obtained by approaching the global problem solution using sequentially solved local problems. For unidirectional and mixed systems, on the other hand, this paper introduces a condition that allows verification of the feasibility of performing process reservations in a staged manner. The fulfillment of this condition means that there is a possibility of obtaining higher efficiency of the transportation system. The effectiveness of the proposed approaches has been verified by simulations. Their results were compared with the results of the original method resulting in a significant improvement.