Adaptive Trajectory Tracking for Nonminimum Phase HSVs Based on HOFA System Approaches

This paper presents a nonlinear adaptive multi-model switching controller designed for the nonminimum-phase longitudinal model of hypersonic vehicles (HSVs) using high-order fully actuated (HOFA) system approaches in the presence of parameter uncertainties. Considering that some controllers designed for nonminimum phase systems require linearisation of the internal dynamics, and the longitudinal model of HSV is a highly nonlinear system, the designed controller can only satisfy stable control near a certain equilibrium point. To broaden the scope of controller application, this paper proposes a multi-model switching control strategy on the basis of HOFA system approaches: 1) HOFA system approaches are used to design the external control inputs; 2) the trajectory optimization algorithm is used to obtain an estimate of the ideal internal dynamics; 3) a multi-model switching control strategy is proposed to ensure the stability of the internal dynamics through a large change in state variations; 4) the gap metric is used to segment suitable switching regions. The system position parameters are estimated using adaptive control methods. The system is proven to be stable by the Lyapunov stability theorem. Other states and signals in the closed-loop system are also guaranteed to be bounded. Simulation results demonstrate the effectiveness of the methodology.