Network controlled tracking of spacecraft formation flying with communication delays

In the networked control systems (NCSs), the formation tracking problem of multiple spacecraft is considered. This paper presents a digital control technique for spacecraft formation keeping in the presence of variable network-induced communication delays and external disturbances. A digital controller is developed to guarantee the exponentially uniformly ultimate boundedness (UUB) of the tracking errors and to ensure desired formation objectives. The proposed digital controller is successful in achieving desired circular formation flying of spacecraft.