Relative Position Controller Design for Spacecraft Formation Flying with Communication Delay

This study considers the relative position coordinated tracking control of spacecraft formation with time-varying communication delay when the desired information are available for only a subset of spacecraft. Firstly, a controller based on sliding mode is designed to track the desired position without communication delay. Secondly, a distributed observer is developed to get the estimation of the desired position and velocity by using the information with time-varying delay of neighbors. Then, based on the observer, a controller is proposed to realize the expected formation configuration. Finally, numerical simulations are provided to illustrate the effectiveness of the proposed control law.