Accurate Control for Gimbal System of Single Gimbal Control Moment Gyro Based on Nonlinear Cascade Extended State Observer

Abstract

The nonlinear friction, unmodeled disturbance and coupling torque caused by the movement of satellite are the main factors limiting the angular speed accuracy in gimbal system of the single gimbal control moment gyro (SGCMG). Consequently, a high-precision servo control system based on the nonlinear cascade extended state observer (NCESO) is established in this paper in order to reduce the influence of those disturbances and improve the output angular velocity accuracy of the gimbal system. The simulation results confirmed the feasibility and effectiveness of the proposed method.