Snake Robot Gripper Module for Search and Rescue in Narrow Spaces

Abstract—This letter presents a gripper module for a snake-like robot to perform search and rescue tasks in a narrow space. The proposed gripper module has three features: (1) It can accommo- date the fingers inside its body. (2) It has three fingers that can grip objects with irregular surfaces stably. (3) One of the fingers is equipped with a camera on the fingertip to search in a narrow space. To implement the above features in a small, light, and compact gripper module, we propose a novel design of a gripper module with three fingers and eight degrees of freedom. The joint configuration of the proposed gripper is unique compared with a general-type gripper. A prototype of the proposed gripper module has been integrated into a snake-like robot to demonstrate its capability of performing rescue tasks in a collapsed environment. The three fea- tures of the proposed gripper module are experimentally verified: it is light (0.4 kg), small (less than 68 mm in diameter), and powerful (grasping force = 2.48kgf). Index Terms—Search and rescue robots, grippers and other end- effectors, mechanism design, snake-like robot.