Dynamic modeling and control of large flexiblespacecraft combination

Abstract

<p indent=0mm>In the mission of spacecraft on-orbit assembly and service, a large flexible spacecraft combination will be formed by the capturing spacecraft and the target spacecraft after the space manipulator completes the capturing misssion. First, taking comprehensive consideration of vibration influence of all the flexible components as the joints, links and solar arrays, the dynamic model of the spacecraft combination is established. The non-linear torsional spring models are adopted for flexible joints description; the assumed mode method and the finite element method are adopted for the flexible links and solar arrays; and the dynamic equation of the flexible spacecraft combination is established by use of the momentum conservation and the Lagrange equation. In addition, a composite controller of the flexible spacecraft combination is designed for trajectories tracking and vibration suppressing. The dynamic model of the flexible spacecraft combination is decomposed by use of the singular perturbation method and the two sub-controllers are designed seperately in two different time scales. Finally, the numerical simulations are carried out to verify the effectiveness of the modeling and control methods. The results illustrate that the dynamic model is accurate and effective for representing the kinematic and dynamic properties of the flexible spacecraft combination, and the composite control method is able to guarantee the trajectory tracking pricision as well as effective vibration suppression of the flexible components. The dynamic modeling and control method are applicable for engineering practice.