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

• Three-axis attitude exponential stabilization via magnetic control is obtained.
• Attitude plus attitude rate feedback and attitude only feedback are presented.
• Robustness with respect to large uncertainties on moments of inertia is obtained.
• Almost periodic model of geomagnetic field is considered.
• Simulations show effectiveness of control algorithms.

In this work feedback control laws are designed for achieving three-axis attitude stabilization of inertial pointing spacecraft using only magnetic torquers. The designs are based on an almost periodic model of geomagnetic field along the spacecraft׳s orbit. Both attitude plus attitude rate feedback and attitude only feedback are proposed. Both feedback laws achieve local exponential stability robustly with respect to large uncertainties in the spacecraft׳s inertia matrix. The latter properties are proved using general averaging and Lyapunov stability. Simulations are included to validate the effectiveness of the proposed control algorithms.