Bioinspired Adaptive Leg-Claw Enables Robust Perching and Grasping for UAVs.

Conventional unmanned aerial vehicles (UAVs) are limited in their ability to perch and grasp, constraining aerial manipulation and prolonged operation in complex environments. Raptors, however, achieve versatile and robust functions through specialized hindlimb morphologies. Inspired by the owl's limb structure and the bat's roosting behavior, we propose a bioinspired adaptive leg-claw mechanism that enables UAVs to perform robust and versatile perching and grasping. Our design integrates a four-link tibia, tension-driven deformable feet, and symmetrical toes to ensure stable attachment to surfaces of varying geometry. An active grasping strategy and control framework are developed to enable autonomous switching between standing and hanging perching modes, and adaptive toe adjustment for grasping diverse objects. The design allows UAVs to seamlessly transition between perching modes, land on branches of different diameters, and grasp irregular objects with stability. The bioinspired mechanism demonstrates significant potential for enabling UAVs to perch and grasp reliably in unstructured environments.