Robust Three-axis Attitude Stabilization for Inertial Pointing Spacecraft Using Magnetorquers

TL;DR

This paper develops robust feedback control laws for three-axis attitude stabilization of inertial pointing spacecraft using magnetic torquers, accounting for geomagnetic field variations and uncertainties in spacecraft inertia.

Contribution

It introduces novel control laws based on an almost periodic geomagnetic model that ensure local exponential stability despite inertia uncertainties.

Findings

Control laws achieve robust local exponential stability.

Simulations validate effectiveness under large inertia uncertainties.

Control strategies work with attitude-only or combined attitude and rate feedback.

Abstract

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.