The autopilot design of bank-to-turn missile using mixed sensitivity H∞ optimization

Bank-to-turn (BTT) missile shows many advantages in performance over traditional skid-to-turn missile, while the autopilot design poses a great challenge for BTT missile because it is a multivariable system with motion, inertia, aerodynamic and control couplings. In this paper, the autopilot for BTT missile is designed as a two-loop feedback control structure. The inner loop feedback controller is designed using LQR control approach to contain the system uncertainty within a certain limit. The outer loop controller is designed using mixed sensitivity H_∞ optimization to deal with the disturbance and model uncertainty. Then simulation experiments of target interception are performed using BTT missile with the designed autopilot under six degrees of freedom. The results demonstrate that the designed autopilot for BTT missile is effective.