For gyroscopic dynamic systems, active damping using direct velocity feedback control with collocated actuator/sensor pairs is discussed in this paper. The proposed method of designing the damping is actually to assign the negative real parts of the poles for specific modes of the uncontrolled system. The targeted values of the negative real parts are determined by desired damping ratios to be gained for the specific modes. The procedure is formulated as solving constrained nonlinear equations or a constrained nonlinear least squares problem wi...