Transition Flight Control of A Small Unmanned Tilt Rotor Aircraft with Distributed Electric Propulsion

Tilt rotor aircraft is a type that has gained wide attention and developed quickly in recent years, combining the advantages of rotorcraft and fixed-wing aircraft, such as vertical takeoff/landing ability and high-speed cruise. An extended dynamics equation, based on six degree-of-freedom (6-DOF), is proposed in this paper, to solve the problem of inertial properties dynamic behavior during transition. Then, the transition corridor is calculated considering force and torque balance based on nonlinear programming. Last, the study focuses on the transition flight of the tilt rotor aircraft with distributed propulsion, which is nonlinear, strongly coupled and uncertain. And due to the significant change in dynamic characteristics, the error in the aerodynamic calculations and the strong external interference. An attitude controller is designed, by Active Disturbance Rejection Control (ADRC) method, as an inner loop control demonstrating excellent dynamic suppression performance. Overall, distributed electric propulsion not only presents unique control challenges, but also provides new solutions for transition flight control. This paper focuses on new properties brought by distributed propulsion to the transition envelope. Furthermore, a robust control method is designed, which may be a new research approach to the tilt rotor aircraft with distributed electric propulsion.