A Robust Control Approach to Missile Autopilot Design Based on Backstepping

Firstly, the nonlinear dynamics model of a slide-to-turn (STT) missile is transformed to benefit from backstepping. Secondly, the autopilot controller is designed based on backstepping, and the astringency of the system is mathematically improved strictly by using lyapunov stability theorem. Afterwards, the influence of actuator position/velocity saturation on the autopilot system's stability is researched, and a nonlinear optimization solution considering the dynamics of the actuators is proposed, which can avoid the complexity of the backstepping process. By this way, a controller which makes compromise between actuator saturation and the missile's autopilot performance as well as robustness is proposed. Finally, the autopilot system's stability and robustness is verified by a great deal of simulation.