A Gripper with Pin-Array Structure for Convex and Concave Terrain Shapes

Abstract

Mobile robots that perform variable missions on behalf of humans are essential in extreme environments such as disaster sites, volcanoes, and space. On cliffs, cave surfaces, ocean floors, and asteroid surfaces, conventional wheeled robots are difficult to maintain their pose due to uneven terrain and the gravitational effect. Therefore, various grippers have been developed and installed in mobile robots to keep the robot's pose. However, because such conventional grippers are limited in the shapes they can grip, the graspable regions are discretely and randomly given in unstructured environments. In this paper, we developed a novel gripper that enables to grasp of both convex and concave shapes in terrain without pre-observation of the shape. The proposed gripping mechanism consists of a passively moving pin array with spines and actively moving holders. Furthermore, the result of gripping performance experiment on emulated terrain shapes shows that the proposed gripper can grip more various shapes than conventional grippers.