Adaptive Fixed-time 6-DOF Coordinated Control of Spacecraft Formation Flyings

In this paper, the fixed-time coordinated control problem is investigated for multiple spacecraft formation flying (SFF) system based on six-degrees-of-freedom (6-DOF) dynamic model. The system under consideration involves input quantization, external disturbance, and directed communication topology. By utilizing the neighborhood state information, a novel multi-spacecraft nonsingular fixed-time terminal sliding mode function is designed. To reduce the required communication rate, a hysteretic quantizer is employed to quantify the control torque and force. The problem addressed is the design of 6-DOF fixed-time coordinated controller such that, the controlled system is practical fixed-time stable and also ensures the relative attitude and position tracking errors can converge into the regions in fixed time.