Robust three-axis attitude stabilization for inertial pointing spacecraft using magnetorquers

In this work a feedback control law is designed for achieving three-axis attitude stabilization of Earth-pointing spacecraft using only magnetic torquers. The design is based on general averaging theory which provides tools for obtaining stabilization without relying on the periodicity assumption of geomagnetic field. The proposed control law is proportional derivative (PD)-like, and with respect to existing control strategies, a novel scaling of the PD gains is presented. Exponential stabilization is proved in the case of isoinertial spacecraft as well as robustness with respect to uncertainties on the spacecraft's inertia moment. Simulations are included to verify the effectiveness and feasibility of the proposed control algorithm.