Design of Pitch Autopilot of High Angle of Attack for Air-to-Air Missile

High nonlinear coupling and parameter uncertainty exist in high angle attack flying for air-to-air missile.A feedback linearization method was used to linearize the missile model based on the nonlinear model of pitch motion for air-to-air missile in this paper with nonlinear characteristic in high angle attack flying,in which the angle of attack was served as the output and command of the fin deflection as its input.Then a variable structure controller was designed based on the theory of sliding mode control.The structure of the controller is simple and easy to realize,and the controller can restrain the uncertainties existing in the controlled device.Using the simulation,the comparison was played between the controller designed based on full state feedback method and feedback linearization method.The contrast results showed that using the methods of the feedback linearization and the sliding mode of the variable structure,the designed control system was of robustness to the perturbation of aerodynamic parameters and the exterior disturbance.