Nonlinear disturbance observer-enhanced dynamic inversion control of missiles

Nonlinear dynamic inversion control (NDIC) is one of the most promising nonlinear control methods in aerospace engineering. For longitudinal dynamics of a missile, a nonlinear disturbance observer-based approach is proposed to enhance its disturbance attenuation ability and performance robustness against uncertain aerodynamic coefficients. Stability of the proposed nonlinear disturbance observer-enhanced NDIC is established. Its flexibility and efficiency are demonstrated by two different choices of the nonlinear gain function in the observer. Simulation results show-that the nonlinear disturbance observer-based technique can significantly improve disturbance attenuation ability and performance robustness of dynamic inversion control.