Study on Characteristic Modeling and Command Tracking Control Method for Variable Configuration Aircraft

This paper investigates the characteristic modeling of a novel foldable wing aircraft and evaluates the control performance of various command tracking controllers. Firstly, a longitudinal four-degree-of-freedom nonlinear dynamical model is developed by employing the screw theory in conjunction with the Newton-Euler method. Then, the linear variable parameter (LPV) model is established with flight-path angle and folding angle as time-varying parameters. A trim and small-disturbance linearization is applied to each working point within the flight mission. Eventually, to ensure the flight stability of the deformation process, this paper employs both LQR and PID controllers, accomplishing the command tracking control for the nonlinear model. Simulation results show that compared with the fixed configuration control strategy, adopting a variable configuration control strategy reduces the angle of attack, thereby mitigating the stall risk caused by the excessive angle of attack during the climbing process. Additionally, the propeller speed is diminished under the variable configuration control strategy, which helps to minimize the flight energy consumption and improve the cruise capability.