CMG Isolator Design with Consideration of Singularity Problem

Abstract

As a powerful torque amplification actuator, control momentum gyroscopes (CMGs) are often used in the attitude control of many state-of-the-art high resolution satellites. However, the disturbance generated by the CMGs can not only reduce the attitude stability of the satellite but also deteriorate the performance of its optic payloads. Currently, CMG vibration isolators are widely used to target this problem. The isolators can affect the singularity of the CMG system as they are placed between the CMGs and the satellite bus and provide additional freedoms to the CMG system due to their flexibility. Another important problem of using a CMG system in the attitude control is the singularity. We at first took a close look at the formulation of the output torque of a CMG considering the dynamic imbalance of its spin rotor, and then calculated the deformation angle as a result of the isolator’s flexibility. With the additional freedoms, we studied the isolator’s influence on the singularity problem and presented a steering logic to escape from the singular states.