A new method for identification of and compensation for periodically disturbing torques of on-orbit satellite

Aim. Pinpointing the difficulty to be that the periodically disturbing torques are usually unknown in both frequency and amplitude, we devise a new method for identifying and then compensating for them. Section 1 of the full paper establishes the complete models of the periodically disturbing torques; essentially, it, using the output data of the steady-state satellite, eigenvalues and eigenfunctions, derives eq. (13) to estimate frequency and eq. (26) to estimate amplitude. Utilizing the mathematical derivation in section 1, section 2 gives eq. (27) for implementing a feedforward compensation algorithm to keep the on-orbit satellite in steady state despite periodically disturbing torques. Simulation results, given in Figs. 1 and 2, show preliminarily that the new method devised by us is indeed successful in keeping the on-orbit satellite in steady state despite periodically disturbing torques; therefore, in our opinion, our new method is valid in high precision attitude control.