A High-precision Backstepping Control Method of Flight Vehicles

In attitude control system of flight vehicles, there are problems of over-coupling and uncertainty in control models. This paper develops a high-precision backstepping control method of flight vehicles. Firstly, the attitude control model is reduced into a nominal model. The nominal model is then decoupled with backstepping design method. Secondly, we design the control law for the nominal model. Besides, the extended high-gain observer is designed for the attitude control model. The observer can estimate the uncertainty of the attitude control system, and compensate the uncertainty back to the original system. Due to that the performance of state feedback can be recovered by output feedback when the gain is high, the observed value is used instead of state value to output the feedback, thus completing the design of control law. Simulations are demonstrated to verity the conclusion.