Descent Angle Control by Regenerative Air Brake Using Observer-based Thrust Control for Electric Aircraft

Abstract

Research and development have been very active in electric aircraft (EA). EA use electric motors as the power source; therefore, EA are expected to achieve more secure, more efficient, and more eco-friendly aviation. Electric motors enable EA to regenerate their potential energy while descending as the windmilling propeller produces negative torque and thrust. This paper proposes descent angle control method by using windmilling propeller as an alternative to mechanical air brakes. In addition, the use of wide range of propeller pitch angle is discussed in order to produce enough drag to eliminate mechanical air brakes. The effectiveness of the proposed method is verified by simulations and experiments in the wind tunnel.