Optimal Gyricity Distribution for Space Structure Vibration Control

Abstract

Many space vehicles have been launched with large flexible components such as booms and solar arrays. These large space structures may require active shape control given the possibility of lightly damped vibrations. Such vibrations can be controlled using a collection of control moment gyros, which consist of a spinning wheel in gimbals and produce a torque when the orientation of the wheel is changed. This study investigates the optimal distribution of these control moment gyros on large space structures for vibration suppression. Initially, a continuum model is adopted that represents the distribution of control moment gyros by a continuous distribution of stored angular momentum (gyricity). The optimal control solution for the gimbal motions (for a given gyricity distribution) is then optimized with respect to the gyricity distribution. Further investigation considers discrete parameter models of beam and a plate structures with evenly placed discrete pointwise control moment gyros. Numerical optimization of a suitable cost function allocates the amount of stored angular momentum possessed by these control moment gyros.