Embodying Compliant Touch on Drones for Aerial Tactile Navigation

Aerial robots are a well-established solution for environmental surveying, exploration, and inspection, thanks to their superior maneuverability and agility. Nowadays, the algorithms that provide these capabilities rely on GNSS and Vision, which are obstructed in some environments of interest, e.g., indoors and underground or in smoke and dust. In similar conditions, animals rely on the sense of touch and compliant responses to interactions embodied in the body morphology. This way, they can navigate safely using tactile cues by <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">feeling</i> the environment surrounding them. In this letter, we take inspiration from the natural example and propose an approach that allows a quadrotor to navigate using tactile information from the environment. We propose to endow a conventional quadrotor with a novel robotic finger that embodies compliance and sensing capabilities. We complete this design with a navigation approach that generates new waypoints based on the robotic finger's contact information to follow the unknown environment. The overall system's evaluation shows successful, repeatable results in 36 flight experiments with various relative angles between the drone and a piecewise planar surface.