Landing, perching and taking off from vertical surfaces

An approach is presented whereby small, unmanned aircraft can land on walls. The approach is demonstrated with a plane that uses an ultrasonic sensor to initiate a pitch-up maneuver as it flies toward a wall. The plane contacts the wall with spines that engage asperities on the surface. A non-linear suspension absorbs the kinetic energy while keeping the spines attached. A planar dynamic model is used to evaluate pitch-up maneuvers and determine suspension parameters that satisfy constraints on the contact forces for a range of flight velocities. Simulations conducted using the model are compared with data obtained using high-speed video and a force plate embedded in a wall.