Comments on “quaternion models of a rigid body rotation motion and their application for spacecraft attitude control”

Abstract

The commented paper discusses the attitude dynamics representation using quaternions. The main idea of the paper is to eliminate angular velocity from the dynamics equations. The obtained equations are interesting. However, all applications presented in the discussed paper have plain errors in the equations derivations. This affects the main results and conclusions of the paper, which require significant corrections. • Errors in commented paper are outlined. • Quaternion dynamics equations application for the attitude control is discussed. • Control singularity is shown.