Attitude-Orbit Coordinated Control of Spacecraft Formation for Heliocentric Gravitational-Wave Detection with Large-Scale Communication Delays

Considering the large-scale communication delays mainly caused by the large detection arm length with several million kilometers in the heliocentric gravitational-wave detection mission, the attitude-orbit coordinated control issue is addressed in this work. Firstly, to describe the formation detection motion in the Sun–Earth system, an attitude-orbit coupled relative motion model of the formation spacecraft is established with the assistance of a virtual structure. Then, a comprehensive model of communication delays caused by the large detection arm length and hardware resource constraints is constructed. Next, to realize the fast convergence of the formation attitude-orbit errors, a reliable and robust integration design of attitude-orbit coordinated control protocol is elaborated by delay-dependent Lyapunov function, in which the unknown lumped disturbances and the aftereffects of large-scale communication delays are suppressed with the adaptive control item and the delay-effect compensation one, respectively. Finally, numerical simulations are constructed with the typical heliocentric gravitational-wave detection mission scenario, verifying the validity and superiority of the proposed method with the existing findings as a comparison.