Agile missile autopilot design for high angle of attack maneuvering with aerodynamic uncertainty

Abstract

The paper proposes a new autopilot design for agile missiles flying at a high angle of attack (AoA). A maneuver strategy applicable to 90° AoA flight for agile turning is described prior to the missile modeling. Accounting for the disturbance rejection, the extended state observer (ESO) technique is employed for online estimation of the system uncertainties due to the aerodynamic unpredictability at high AoA regimes. Under the circumstances, linearization with dynamic compensation and non-singular terminal sliding mode control are applied to achieve controllability during 90° AoA flight. Numerical simulation results demonstrate the effectiveness and robustness of the proposed scheme. Additionally, the chattering caused by unmodeled dynamics is obviously mitigated with the action of the ESO.