This paper describes mobile robot tactics for recovering a wheeled vehicle that has overturned. If such a vehicle were to tip over backward off its wheels and become unable to recover itself, especially in areas where it would be difficult for humans to enter and work, total working efficiency could decline significantly, not only because the vehicle is no only able to perform its job, but because it becomes an obstacle to other work. Herein, we propose a robot-based recovery method that can be used to recover such overturned vehicles and demonstrates its utility. The recovery robot, which uses a mounted manipulator and hand to recover the overturned vehicle, is also equipped with a camera and a personal computer (PC). The ARToolKit software package installed on the robot-mounted PC detects ARmarkers attached to the overturned vehicle and uses the information they provide to orient itself in order to perform recovery operations. To facilitate these ARToolKit-based operations, it is necessary to conduct a theoretical analysis to clarify the distance between the robot manipulator and vehicle, and thus achieve an objective position for grasping the overturned vehicle. The experimental results obtained in this study demonstrate the effectiveness of our proposed system.
