Abstract
Recently rapid maneuvering and precision pointing accuracy are two crucial characteristics for observation missions of microsatellites. Control moment gyroscopes (CMGs) are applied as ideal actuator for large torque output capability but are limited to the problem of inherent mechanical singularity. This paper proposes a simple yet effective robust attitude control methodology for microsatellites. It can guarantee convergence time and pointing accuracy in the presence of CMG practical restrictions, inertial uncertainties and various disturbances. Furthermore, pseudo-inverse steering logic based on mixed two-norm and least-squares minimization is chosen, as it can deal with both the internal singularity problem and momentum saturation singularities. It aims at precisely exporting commanded torque while avoiding singularity at the same time. Two key parameters of this steering logic and their characteristics for avoiding singularity are introduced. Hardware in the loop simulation result demonstrates the efficiency and feasibility of the proposed attitude control approach.
