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

Perching has recently emerged as a significant trend in aerial robotics, offering enhanced energy efficiency and operational flexibility. This capability enables aerial robots to extend mission duration and adapt to dynamic environments ranging from wildlife monitoring to urban surveillance. In this work, we present a novel perching mechanism capable of both branch and surface perching. For branch perching, the mechanism uses four simultaneously-actuated claws to grasp a branch, enabling perching onto branches up to 35 mm in diameter. For surface perching, it leverages a bistable mechanism with five suction cups, allowing effective perching onto flat smooth surfaces with large orientation misalignment (up to 80◦ of the surface tilt angle). The mechanism is fabricated using a combination of multimaterial 3D printing and silicone molding, resulting in a lightweight prototype with a mass of 32 g. Experimental evaluation demonstrates that the proposed design achieves 6.4× 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.