Distributed fault-tolerant control design for spacecraft finite-time attitude synchronization

This paper develops two distributed finite-time fault-tolerant control algorithms for attitude synchronization of multiple spacecraft with a dynamic virtual leader in the presence of modeling uncertainties, external disturbances, and actuator faults. The leader gives commands only to a subset of the followers, and the communication flow between followers is directed. By employing a novel distributed nonsingular fast terminal sliding mode and adaptive mechanism, a distributed finite-time fault-tolerant control law is proposed to guarantee all the follower spacecraft that finite-time track a dynamic virtual leader. Then utilizing three distributed finite-time sliding mode estimators, an estimator-based distributed finite-time fault-tolerant control law is proposed using only the followers' estimates of the virtual leader. Both of them do not require online identification of the actuator faults and provide robustness, finite-time convergence, fault-tolerant, disturbance rejection, and high control precision. Finally, numerical simulations are presented to evaluate the theoretical results.