Control law for active structural damping using a control moment gyro

The use of a single-gimbaled control moment gyro (SGCMG) whose output torque axis is nominally collocated with an angular velocity sensor and is located at the end of a cantilevered beam, was discussed. A SGCMG with collocated angular rate sensor was designed and built at the University of Toronto Institute for Aerospace Studies. It was demonstrated mathematically and experimentally that direct feedback between the angular rate sensor and the gimbal rate leads to asymptotic stability. A simple modification to the feedback law that incorporates an additional term proportional to the gimbal angle was shown to remedy this drawback and preserve the robust stability of a straight feedback gain.