Tilt rotor aircraft conversion control based on nonlinear model predictive control

A nonlinear model predictive control based on a reduced order model and smooth switching control was proposed for the conversion maneuvering of tiltrotor aircraft. The simulation model and the reduced order prediction model of tiltrotor aircraft were established. In the framework of the model prediction algorithm， the reduced order model was used to predict the successor states of the vehicle. Combined with smooth switching control of speed and altitude，along with the nacelle control strategy of segmented nacelle tilting rate，the command tracking objective function suitable for transition maneuvering was derived. The control saturation， pitch angle rate， and pitch angle limits were considered in the constraints. The performance of the conversion control method on attitude and rate command tracking during different conversion phases and dynamic transition maneuvering was verified by flight simulations，respectively. Results showed that the inherent characteristics of aircraft at different nacelle angles had little impact on the tracking performance of the controller. In the conversion maneuvering，the controller and the nacelles control strategy enabled the aircraft to complete the conversion procedures with small altitude variation and smooth pitch attitude variation，and the speed tracking and the attitude holding of lateral and heading were excellent. © 2023 BUAA Press. All rights reserved.