Attitude stabilization control of flexible satellites with high accuracy: An estimator-based approach

This paper presents a novel nonlinear control approach for attitude stabilization of flexible satellites. It is developed by using a nonlinear estimator technique. An estimator is proposed to estimate external disturbances and unknown flexible vibrations acting on the satellite. Applying the estimated value, a compensation control effort that compensates for such effects in real-time is derived and added to the nominal controller to accomplish the desired attitude maneuver. The proposed controller guarantees the closed-loop system to be asymptotically stable, and provides high-accuracy control, external disturbance rejection, and robustness to flexible vibrations. The key feature of this approach is that the controller has no conservativeness. The effectiveness of the approach is verified through both simulation and experimental results.