Strategy for using a robot to rescue a rolled-over robot and validation of its effectiveness

If we can establish a technology that enables a robot to restore a rolled-over robot to its original state in an environment that is inaccessible to humans, we can dramatically improve the capabilities of multi-robot operations. This paper describes a strategy for using a mobile robot to rescue another robot that has rolled over and become unable to move. The rescue robot and the rolled-over robot both have individually driven wheels. Both body sizes are the same, and the rescue robot is equipped with a manipulator that has a robotic claw-like hand. During the recovery process, the mobile robot grasps the rolled-over robot using the robotic hand and applies a force to the overturned robot to recover it from the rolled-over state. A recovery strategy that uses a method to passively control the manipulator joints was developed. Using this method, the rescue robot can apply a pushing and pulling force to the rolled-over robot and avoid the influence of control errors of the joint angles that causes slippage of the driving wheels or tipping over of the rescue robot. The robotic hardware was designed and experiments were conducted. The results showed that factors such as the center of gravity of the overturned robot and the direction of the force received from the manipulator and connecting position between both vehicles cause the rolled-over robot to rotate significantly in the yaw axis direction just before the recovery process is complete. However, it became clear that if these issues are addressed appropriately, our rescue method is quite effective.