Active Disturbance Rejection Three-Loop Acceleration Autopilot Design

A novel three-loop acceleration autopilot was proposed by keeping the damping and the stabilizing loops of the classical three-loop autopilot unchanged and replacing the acceleration loop with an active disturbance rejection controller. Extending the dynamic estimation and compensation functions of the state observer, the robustness to the uncertainties in the aerodynamic coefficients could be enhanced while the stabilizing capability for the static unstable missile and the speediness could still be maintained. The classical and the proposed three-loop autopilots were compared via a benchmark of a highly maneuverable missile represented by a time-varying nonlinear model. The simulation results demonstrate that the robustness of the proposed method outperforms the classical one.