Attitude Rate Damping Control of a Stratospheric Balloon Gondola with CMGs

Abstract

This study investigates the attitude rate damping control of a stratospheric balloon gondola using three-axis momentum-exchange devices, which are mounted on the gondola. To this end, we propose a steering law considering four single-gimbal control moment gyros. The stratospheric balloon system can be modeled as a three-rigid-body system comprising a balloon, gondola, and suspension string connecting the gondola with the balloon. Based on this model, the target torque for the rate damping control is derived from Lyapunov's stability theorem. We propose the analytical solution of time evolutions for the deflection of the suspension against the balloon and the mechanical energy of the stratospheric balloon system under control. Numerical simulations demonstrate that mechanical energy monotonically decreases. Moreover, the accuracy of the analytical solutions is also demonstrated.