Fixed-time 6-DOF coordinated control of spacecraft formation flying

This paper investigates the fixed-time coordinated control problem of six-degrees-of-freedom (6-DOF) dynamic model for multiple spacecraft formation flying (SFF) with external disturbances. A new multi-spacecraft nonsingular fixed-time terminal sliding mode vector is derived. Then, a 6-DOF fixed-time coordinated control strategy with adaptive tuning laws is proposed, such that the practical fixed-time stability of the controlled system is ensured in the presence of upper bounds unknown external disturbances. It theoretically proves that the relative tracking errors of attitude and position can converge into the regions in fixed time. Finally, a numerical example is exploited to show the usefulness of the theoretical results.