Spacecraft angular velocity estimation from inertial vector measurements: A parameter estimation approach

A parameter estimation alike solution to the angular velocity estimation problem of rigid-body spacecraft is presented in this paper, where direct inertial vector measurements rather than attitude information are considered as available outputs. The main idea is to transform the original state estimation problem into an equivalent linear regression problem of an unknown time-varying parameter through employing physical intuitions on attitude motion and technics in parameter estimation, and a uniformly globally exponentially convergent observer with arbitrarily fast possible convergence rate is then established on this basis. Compared with existing approaches on similar problems, it is demonstrated that high-gain feedback is not necessary to ensure such convergence. Performance improvements of the proposed observer under measurement noises are illustrated by numerical simulations.