A mechanical adhesive gripper inspired by beetle claw for a rock climbing robot

Abstract

Rock climbing robots have wide application prospects in field operations and planetary exploration. Herein, a spiny gripper inspired by the beetle (Coleoptera) claw is developed, which can accomplish easy attachment, detachment and good compliance on irregular rough surfaces without complex controls. The attachment probabilities of various microspine layouts are simulated to determine the optimal design parameters for the spine tile. By referencing the structure and attachment process of the beetle claw, a spiny gripper with four bioinspired branches is designed to enable adaptive attachment and smooth detachment. The gripper employs a novel drivetrain hybridized with passive torsion springs and active tendons driven by an ingenious winch to achieve light weight, load-sharing, self-adaptation, and strong adhesion on irregular rough surfaces. The grasp sequence, grasp wrench and gripper maximum adhesion are all investigated. Tests on various surfaces verify its excellent performance. With a weight of 0.352 kg, its normal adhesion and tangential adhesion are 39.7 N and 47.5 N, respectively. In addition, the gripper is integrated into the climbing robot RockClimbo to allow it to move on extreme terrain.