H∞-based torque equilibrium attitude seeker designs for the reaction control system of the Space Station

In this paper we consider the problem of torque equilibrium attitude seeker design for the reaction control system (RCS) of the Space Station Freedom (SSF). The objective of this design was to achieve a combination of good performance, i.e. minimize fuel consumption and adequate stability margins. Classical control design techniques failed to produce a satisfactory seeker design due to strong cross-coupling between the roll and yaw axes. However, H^∞-synthesis techniques were able to successfully treat these coupling effects and produce a seeker design which achieved the desired objectives