Spacecraft Attitude Control using Internal Model Principle

Paper title

“Spacecraft Attitude Control using Internal Model Principle”

Authors: Ahmed Z. Al-Garni1, Rihan Ahmed1, R. Doraiswami2, Ayman Kassem1
Affiliation: 1. Aerospace Engineering Department, K.F.U.P.M., Dhahran, Saudi Arabia
2. University of New Brunswick, Fredericton, NB, Canada

Abstract — In this paper, we propose a design methodology for the tracking of Spacecraft attitude. The plant (spacecraft model) is a sixth order nonlinear multiinput- multi-output system. The attitude tracking objective is accomplished using Internal Model principle. Internal model of reference and disturbance signal driven by the tracking error is included in the controller. The augmented system formed of the nonlinear plant and the internal model is stabilized by output feedback, where the derivative of the attitude is obtained from the attitude measurement using a differentiator. Small gain theorem is employed to determine the feedback gain of the nonlinear plant. Computer simulation results are given to illustrate the effectiveness of the proposed controller.