Hierarchical optimal time path planning method for a autonomous mobile robot using A∗ algorithm

This paper presents a hierarchical optimal time path planning method which can handle time constraints of the optimal path in complex and dynamic environments. The optimal time path minimizes a sharp change of orientation and waiting time to avoid a collision with moving obstacle. The path generation problem is divided into three sub-problems. The first is to generate the smooth global path using the A* algorithm. The second is to solve the optimization problem which computes the maximum velocity and the time permitted for a robot in the obstacle zone. The third is to adjust the time interval for obtaining the shortest path using the motion information of moving obstacles and the maximum velocity of a robot. To show the validity and effectiveness of the proposed method, realistic simulation is performed.