Underactuated Satellite Attitude Control with Two Parallel CMGs

Abstract

Abstract-In this paper, we study the attitude stability and the disturbance attenuation properties for an underactuated spacecraft equipped with two parallel CMGs. We first present the actuator configuration and then compare this with typical fully actuated CMG-based configurations. The system model is then derived. Considering the pointing of an underactuated spacecraft, we derive a Lyapunov control law which is further modified to a dissipative controller to account for disturbances. Simulations are included to demonstrate the effectiveness of the proposed control law to attenuate perturbations and to render the underactuated attitude closed-loop system to a dissipative system.

Nonlinear Model Predictive Detumbling of Small Satellites with a Single-Axis Magnetorquer

“…In general, control of a satellite that becomes underactuated as a result of onboard failures has been a recurrent theme in the literature; see, e.g., [8,9] and references therein. Methods for controlling spacecraft with fewer actuators than degrees of freedom are increasingly in demand due to the increased number of small satellite launches [10].…”