Transition Flight Control of the Distributed Propulsion Tilt-Rotor Aircraft

Distributed propulsion tilt-rotor aircraft has multiple propulsion systems, which brings larger difficulties in the transition controller design. In this paper, the control for the transition flights of the distributed propulsion tilt-rotor aircraft is studied. A coordinated tilting strategy is firstly developed for distributed propulsion systems based on the Sigmoid function, which achieves smooth tilting thanks to the first increasing and then decreasing tilting angular velocity. Based on that, a discrete-time LQR controller with a predefined decay rate is designed for the transition flights, ensuring both a minimum decay rate and the desired pole configuration. Forward and backward transition simulation flights were conducted in the newly developed Matlab + X-plane platform to corroborate the effectiveness and robustness of the transition trajectory and the control law.