Result and evaluation of solar arrays flexibility identification experiment of Chang’e-5 orbiter

On April in 2021,the Chang’e-5 orbiter carried out a solar arrays flexibility identification experiment during the Sun-Earth LI point exploration flight. By injecting high-bandwidth PID parameters for momentum wheels control system, the spacecraft’s attitude was perturbed by two flexible solar arrays. The analysis of attitude data shows that the mode frequency error of the solar arrays is less than 13%, and the structural damping factor is about 0.002 during the stable resonance. By analyzing the angular velocity data of the orbiter during convergence process after restoring low-bandwidth PID parameters, it is shown that the damping factor is positively correlated with the panel’s vibration amplitude, and is only 0.0015 at the equilibrium position, which is far less than the set value usually used in the attitude controller design. The experimental identification results provide technical support for the design of flexible spacecraft attitude controller. In this paper, we will show the results and evaluations of the experiment.