Steering law design for SGCMGs taking gimbal servo characteristics into account

Gimbal servo systems of single gimbal control moment gyroscopes (SGCMGs) are often assumed to have ideal tracking performance during the steering law design. The tracking performance can be decreased due to the finite bandwidth and various disturbances of gimbal servo systems. In order to attenuate the effect of gimbal servo systems on steering performance, a steering law was presented. This steering law was designed not only based on kinematics, but also dynamics of SGCMGs, and could calculate the control torque for each SGCMG gimbal directly according to the momentum (or torque) command. Since it has no arithmetic singularity, steering error can be made converge to zero exponentially when system singularities do not appear. Comparatively, it has a simple form and is easy to be realized. Simulation results of a certain 4-SGCMG system indicate that the algorithm is feasible.