Distributed adaptive attitude consensus of networked spacecraft on directed graphs

In this paper, we address attitude consensus problem of multiple spacecraft in the presence of dynamic uncertainties and bounded constant time delays. The agents are assumed to interact on strongly connected graphs. The consensus objective is achieved via the construction of the reference systems, where the quaternion-based nonlinear inner coupling of the attitudes is utilized as the reference control input such that the attitudes of the reference systems are driven to synchronize asymptotically. Then, based on the reference systems, we perform the quaternion-based adaptive controller design to achieve consensus of the networked spacecraft. The convergence of consensus errors is proved with energy-based analysis structure and Lyapunov stability tool. Finally, simulation with networked spacecraft is included to validate the effectiveness of the proposed strategy.