Path planning for mobile robot in a 2.5-dimensional grid-based map

Purpose - Two and one half-dimensional (2.5D) grid maps are useful for navigation in outdoor environment or on non-flat surface. However, little attention has been given to how to find an optimal path in a 2.5D grid map. The purpose of this paper is to develop a path-planning method in a 2.5D grid map, which aims to provide an efficient solution to robot path planning no matter whether the robot is equipped with the prior knowledge of the environment. Design/methodology/approach - A 2.5D grid representation is proposed to model non-flat surface for mobile robots. According to the graph extracted from the 2.5D grid map, an improved searching approach derived from A* algorithm is presented for the shortest path planning. With reasonable assumption, the approach is improved for the path planning in unknown environment. Findings - It is confirmed by experiments that the proposed planning approach provide a solution to the problem of optimal path planning in 2.5 grid maps. Furthermore, the experiment results demonstrate that our 2.5D D* method leads to more efficient dynamic path planning for navigation in unknown environment. Originality/value - This paper proposes a path-planning approach in a 2.5D grid map which is used to represent a non-flat surface. The approach is capable of efficient navigation no matter whether the global environmental information is available at the beginning of exploration.