Hypersonic Vehicle Longitudinal Control Using Adaptive Time-Varying Terminal Sliding Modes

This paper presents an adaptive terminal sliding mode dynamic inversion control method. The hypersonic vehicle model is uncertain, multi-variable, unstable, and possesses significant input-output cross-coupling for its extremely wide range of operating conditions and rapid change of mass distributions. Therefore, it is essential to design flight controllers with high non-linear control ability and robustness for hypersonic air-crafts. By using a function augmented sliding hyperplane, it is guaranteed that the output tracking error converges to zero in finite time which can be set arbitrarily and by designing adaptive control law, uncertain parameters can be identified. Simulation results indicate that the proposed methodology may constitute a feasible approach towards the development of robust nonlinear controllers for this type of applications.