Longitudinal Tracking Control for a Morphing Waverider Using Adaptive Super Twisting Control

Abstract

The morphing aircraft is a promising solution to achieve an optimal flight performance according to various mission scenarios. To apply the morphing technology in hypersonic vehicles, a variable-sweep-wing morphing waverider was proposed in previous studies, and its aerodynamic performance and dynamic model were presented. In this paper, this morphing waverider is assumed to perform a long-range unpowered glide mission over a wide speed range from hypersonic to subsonic speed. First, the accurate longitudinal dynamic model for the morphing waverider is presented, with all the additional forces and moments that stem from morphing. And a control-oriented longitudinal dynamic model is proposed and it separates the additional morphing forces and moments from derivatives of state variables. Then, an adaptive super twisting sliding mode controller is applied for this morphing waverider to track the optimized trajectory during the entire morphing process. Finally, the overall performance of this controller is examined by nominal condition simulations and Monte Carlo runs. Under the nominal condition simulations, the adaptive super twisting algorithm based sliding mode controller reduces mean tracking error of the pitch angle by 25% compared with the traditional sliding mode controller. In the 500 Monte Carlo runs, the ASTA controller reduces maximum tracking error of the pitch angle by 47% compared with the SMC controller.