Abstract:
This paper details the development of a tailsitter unmanned aerial system (UAS) that has the potential to be airlaunched in the near future. By simultaneously integrating air-launch capability with both rotary-wing vertical flight and fixed-wing horizontal flight, the vehicle can be rapidly deployed, perform hovering flight, and achieve high-speed and efficient cruising flight. The aircraft prototype has a mass of 1 kg (2.2 lbs) with wings that can fold to allow the aircraft to fit inside a 6-inch launch tube. A coaxial propeller with vectored thrust is used for control in vertical flight, and a unique avian-inspired wing-folding mechanism is used for stowing and deploying the wings. The aerodynamic design was characterized through a series of wind tunnel experiments, propeller tests, and flight dynamics simulations. High-fidelity simulations of vehicle dynamics validated its air-launch capability and flight tests performed with the prototype demonstrated the ability of the aircraft to perform hovering, transitioning, and fixed-wing cruising flight. To date, this aircraft has achieved speeds of up to 130 km/hr (81 mph), and range up to 10 km (6.2 miles).