Feedback linearization control of uncertain satellite attitude based on disturbance estimation and state observation

Aiming at the satellite attitude tracking control problem with unknown disturbances, parametric uncertainties and immeasurable states, the method of feedback linearization control based on disturbance estimation and state observation is proposed. Firstly, the disturbance estimator is employed to estimate the composite disturbance that comprises the effects of unknown disturbance torques and model parametric uncertainties. Further, the state observer with unknown disturbance is employed to approximate immeasurable states. The attitude tracking control law is then presented with feedback linearization method based on the designed disturbance estimator. Finally, the simulation results illustrate the effectiveness of the proposed strategy in improving the satellite attitude control accuracy as well as the system robustness.