Space-time Map based Path Planning Scheme in Large-scale Intelligent Warehouse System

Abstract

As an important part of large-scale intelligent warehouse system, path planning by considering the cooperation among automated guided vehicles (AGVs) becomes an important factor to enhance the efficiency of the system. To this end, we propose a novel path planning scheme based on space-time map with the target of improving the path planning efficiency. Specifically, we first model the time dimension and construct a space-time map to obtain the planned path information of the intelligent warehouse system. Then, by taking the size of AGV and turning cost into consideration, we design a node extension algorithm to limit the search direction of AGVs. To decrease the complexity of the proposed algorithm and improve the efficiency of head-on conflict avoidance, a time window based piecewise path planning method and a mechanism of protected zone are developed, respectively. Simulation results show that the proposed space-time map based path planning scheme has a better performance than the conventional method in terms of the number of turns, the system running time and the moving distance of AGVs.