An energy-effective altitude controller of a pusher-type hybrid UAV in transition phases
Thanh‐Truong Nguyen, Dung Van Vu, Sinh Xuan Mai, Dong Thanh Nguyen · 2022 International Electrical Engineering Congress (iEECON) · 2022
Recent decades have witnessed an increasing interest in QuadPlane UAVs (unmanned aerial vehicles) thanks to its automatic ability in vertical takeoff and landing (VTOL) without a pilot and a runway. However, pusher-type QuadPlane UAVs show a disadvantage in the sense of maintaining a useless payload (quad motors) during the flight time; that is, the quad motors are only used about 5 minutes in only VTOL phases while a flight time is usually about 3 hours. Reducing the quad rotors' weight requires an energy-effective altitude control law, which also plays an essential role in guaranteeing flight safety because there is redundant energy to deal with an emergency. This paper introduces an energy-effective altitude control law for a pusher-type QuadPlane UAV in transition phases based on the sliding mode control technique. The proposed control law estimates the aerodynamic force in the longitude channel to reduce required quad energy based on UAV state and aerodynamic coefficients. Simulation and actual flight test results show that the proposed control law is better than the standard PID controller in terms of altitude tracking errors (about four times) and energy (about 1.5 times).