Design of discrete control system of flexible spacecraft maintaining robust stability of elastic oscillations

For the flexible spacecraft with a nonlinear orientation control system using flywheel engines, an approach to making its elastic oscillations robust stable was considered. It relies on a purposeful variation of the boundaries of the stability domains in the parameter space of the spacecraft and controller with the aim of maximizing the number of robust stable elastic modes of the flexible spacecraft. To make its control stable in the large, consideration was given to the possibility of expanding the basic algorithm by adding the sum of the components using the estimated coordinates of the remaining series of low-frequency unstable modes. Presented was an example of mathematical modeling of the proposed spacecraft orientation system which corroborated operability of the approach making the multifrequency spacecraft stable to the elastic oscillations.