The return way path planning of an autonomous mobile robot considering traveling risk of the road

Since it is difficult to obtain accurate environmental maps at the disaster site, an autonomous mobile robot moves to the destination while updating the environmental map based on the information observed by the equipped sensors. Therefore, it is a difficult task to return safely to the departure point after the robot reached the destination point and completed the instructed task. In this study, we propose a method for an autonomous mobile robot to return safely from the destination point to the departure point in static partially unknown environment. On the outward way, the robot updates the environmental map using traveling risk evaluation scores quantifying the safety of the terrain. Then, in the return way planning, the optimum route is searched using the distance and the risk evaluation score as indices. We implement the combination of A∗ algorithm and iterative search method for path planning. In order to validate the effectiveness of the proposed method, computer simulation using the virtual environment was performed.