Development of a Mobile Manipulator for Underground Excavation Task

A national research and development program on Underground Development Technology has started in 1989. In this program, a basic study of a excavating robot has been done at the Mechanical Engineering Laboratory. This paper describes an experimental mobile manipulator for the excavating task. Four legs and a pair of crawlers are equipped with the mobile platform, and a manipulator is set on it. Legged locomotion has potential to move on rough terrain, and crawlers contribute fast locomotion. When the robot is supported by the legs, not only the position but also the posture of the robot body can be controlled without changing foot points. This feature shows that legs can be used for assisting manipulator task also. For efficient task performance, an coordination control method between the arm and the legs are introduced, and it is tested by an experiment.