Attitude control law for reentry vehicle based on extended state observer

In this paper, an attitude control method based on Extended State Observer (ESO) is developed. The proposed scheme allows for uncertain influences in the system, such as the aerodynamic cross coupling, inertial coupling between each channel in the attitude motion and model parameter uncertainties. In order to decrease the influences, this method uses an ESO to estimate the total influence of various disturbance factors. The simulation result shows that the proposed controller based on ESO can suppress the influence of channel coupling effectively. The control precision is greatly improved compared with the traditional method.