Robust Sliding Mode Control for Hypersonic Cruise Missile Using Dynamic Pressure Feedback

Hypersonic Cruise Missile (HCM) generally adopts the air-breathing scramjet engine as the propulsion, which needs strict conditions of the missile flight dynamic pressure. It is crucial to satisfy the dynamic pressure conditions for scramjet powering on when the aerodynamic drag or thrust is deviated during the standard trajectory command tracking. In this paper, a novel robust control system is presented that the autopilot of HCM adopts the dynamic pressure directly as feedback variable to track the command. To ensure the accurate tracking of dynamic pressure and the stability of attitude, a four-dimensional model of HCM including dynamic pressure and normal overload is deducted. Meanwhile, to deal with the unmodeled dynamics and the external disturbances, a sliding mode controller is designed to guarantee the stability and robustness. The stability analysis of the overall system under the proposed control method is investigated via the Lyapunov theorem. Simulation results show that the proposed controller can ensure good tracing performance of the HCM while existing deviations of aerodynamic drag or thrust, unmodeled dynamics and external disturbances.