Robust Optimal Control for Roll Angle Based on Fully Actuated System Approach

This paper proposes a roll attitude stability control method based on a high-order fully-actuated system approach with nonlinear roll dynamics. In order to derive the control method, the nonlinear dynamic model of the roll channel is established, and a linear extended state observer is designed to estimate the system state, model uncertainty, and external disturbance. Then, the nonlinear controller of the high-order fully-actuated system approach was designed using the estimation information to linearize the nonlinear system, based on the obtained linearized system, the optimal quadratic controller was designed. Further, considering the actuator dynamics, the virtual control command was tracked under the backstepping method. Based on the above method, the roll-channel robust optimal control was achieved and the 'differential explosion' phenomenon of the traditional backstepping method was avoided completely. To evaluate the performance of the proposed control method, numerical simulation is conducted. The result demonstrates that the proposed control method enables the missile to achieve the desired roll angle tracking under the influence of nonlinear uncertainty factors.