Attitude tracking of rigid spacecraft without angular velocity measurements via passivity approach

In this paper, the attitude tracking problem of rigid spacecraft without inertial or relative angular velocity measurements is investigated. The minimal attitude description, the modified Rodrigues parameters (MRPs), are utilized as the attitude parameters for the non-redundancy. The inherent passivity of the system describing the attitude tracking motion of the spacecraft is exploited. Then an attitude tracking control law using feedback parts of relative angular velocity and relative MRPs is designed. Additionally, to remove the requirement of the relative angular velocity measurements, a lead filter is utilized to provide the information for the tracking control problem with relative attitude measurements only. Finally, a numerical simulation is employed to verify the proposed control algorithm.