A Hybrid Perching Mechanism for Aerial Robots: Branch and Surface Perching Robust to Large Surface Orientation Misalignment

Abstract

Perching has recently emerged as a key capability in aerial robotics, enabling substantial gains in energy efficiency and operational endurance for long-duration missions. In this work, we present a multifunctional perching mechanism capable of both branch and surface perching. For branch perching, the mechanism uses four simultaneously-actuated claws to grasp branches with diameters up to 35 mm. For surface perching, it leverages a bistable mechanism with five suction cups, allowing perching onto flat smooth surfaces with large orientation misalignment (with surface tilt angles of up to <inline-formula><tex-math notation="LaTeX">$\mathbf{80}^\circ$</tex-math></inline-formula>). The mechanism is fabricated using a combination of multimaterial 3D printing and silicone molding, resulting in a lightweight prototype with a mass of 32g. Experimental results show that the proposed design achieves <inline-formula><tex-math notation="LaTeX">$\bm{6.4\times }$</tex-math></inline-formula> adhesion success compared to a bistable mechanism with a single suction cup. Furthermore, real-world perching experiments onto cars and tree branches demonstrate the effectiveness of the mechanism in different environments, highlighting its potential for energy-efficient and adaptable aerial robotic operations.