Satellite Attitude Control Using Single Gimbal Conrol Moment Gro(SGCMG)

As attitude actuator, Single Gimbal Control Moment Gyroscope(SGCMG) isused by more and more spacecraft due to its superior performance.Facing more andmore complex environment from the external disturbance, panels,parameterperturbation and so on,robust attitude controller is needed for satellite attitude control’saccuracy and stability.Using SGCMG in satellite attitude control is brought out in-depthresearch, and main following several aspects is done in this paper.SGCMG can provide precise high torque, overcome limitations of the flywheelsmall torque as well as the limitations of fuel demand to thruster, but SGCMG’sdynamics relative to reaction flywheel is more complex, in order to achieve high controlprecision, complete SGCMG dynamics model is established.The coupling effectsbetween SGCMG and satellite is analyzed.SGCMG’s high-speed rotation rotor bingsunbalanced torque to satellite system. Disturbance torque from outer frame such asfriction, pulsating, coupling torque and so on, challenges accurate and stable outputtorque,for the inner rotor dynamic imbalance, dynamic unbalance model is establishedfirstly and the vibration isolator of three parameters is designed to reduce impact on thestability of the satellite, the PID controller with voltage compensation and adaptivecontroller is brought in this paper,aiming at reducing the disturbance’s affect toSGCMG’s servo system.In addition to the external environment, satellite exists flexible panels andparameters perturbation.Attitude control algorithm needs to ensure that satellite havestronger robustness and adaptability.Active Disturbance Rejection Control(ADRC) isadopted in this paper, ensuring the attitude controller’s robustness.Smooth angularacceleration of the transition is designed in ADRC to weak the incentive of panels forreducing flexible panels vibration.Nonlinear observer is designed to measure theunknown disturbance then dynamically feedback it to ADRC, and nonlinear PID also isdesigned to suppress the residual.