Passivity-based nonlinear attitude regulation of rigid spacecraft subject to control saturation

This paper investigated the problem of attitude regulation control of rigid spacecraft subject to control saturation. Both full-state feedback and output feedback control schemes were presented. For the latter case, the requirement for angular velocity measurement was eliminated using passivity technique. Both controllers were shown to guarantee global asymptotic stabilization for the spacecraft attitude and angular velocity, and the control torques required were well within the specified control magnitude constraint. Unit quaternion representation was used in the kinematics due to its void of singularity. The controllers derived are independent of spacecraft inertia matrix, and thus robust to parametric uncertainty. Simulation results were included to confirm the validity of the proposed approach.