Compact lightweight magnetic gripper designed for biped climbing robots based on coaxial rotation of multiple magnets

Abstract

Biped climbing robots can move and work in three-dimensional steel structures, but are extremely sensitive to the weight, size, and adsorption performance of the devices attached at both their ends. Herein, we propose a novel gripper for biped climbing robots comprising two layers of multiple fan-shaped permanent magnets, wherein the upper layer can coaxially rotate with respect to the lower layer. The novel magnetic gripper can switch between the release and adsorption states by rotating the upper layer of magnets to a particular angle, and it can approximately linearly control the adsorption force by varying this rotation angle. The structural parameters and layout of the magnets were studied and optimized, and the adsorption characteristics of the gripper were analyzed via simulations and verified via experiments. Additionally, the proposed magnetic gripper was applied in a biped climbing robot for verifying the effectiveness of the design based on three climbing tests. The results revealed that the proposed magnetic gripper outperformed the existing models in terms of adsorption force to mass ratio. The proposed gripper design offers the advantages of compact structure, simple control, and natural self-locking of the release and adsorption states.