Pterodactyl-Inspired Unmanned Aerial Vehicle with Multimodal Locomotion

Bio-inspiration has led surprisingly to a wide variety of robotic design, especially small Unmanned Aerial Vehicles (UAV), taken cues from birds, bats, and insects. Tapejara wellnhoferi, a pterodactyloid from the Early Cretaceous of Brazil, shows promise as a biomimetic model to develop an UAV of much superior range, a sensor platform capable of aerial, terrestrial, and aquatic locomotion. Tapejara was a sophisticated flyer capable of steady level flight with a cruising speed of 30 km/hr. Both membranous cranial sail and wings acted as large sensory organs during flight. The vertical cranial sail was richly supplied with nerve endings and blood vessels that acted as a mechanoreceptor to sense temperature, pressure, and wind direction. It would transmit aerodynamic information to the vestibular apparatus in the inner ear, a tiny gyroscope, which would instruct the wings for flight control and stability. The cranial sail was positioned at the nose to enhance the aerial turn, a novel adaptation never used in aircraft design. On land, Tapejara first walked quadrupedally and then ran bipedally to reach the takeoff speed. In aquatic environment, Tapejara achieved the configuration of a three-masted sailboat for cruising slowly during foraging. The cranial sail served as a front rudder to steer. Two upright triangular wings, partly folded and oriented transverse to the body axis and anchored at the wrist joint, functioned as a pair of mainsails to catch the wind and supply the thrust while skimming. With a wide range of multimodal locomotion, Tapejara has a strong application to prototype a small functional air-ground-sea robotic (Pterodrone) with a wingspan of 80 cm that will provide autonomous surveillance across a variety of operation areas. Some novel pterodactyl-inspired designs include a vertical tail at the nose of the aircraft to reduce turn radius, and morphing limbs for multimodal locomotion.