Robust adaptive cooperative tracking control for multi-spacecraft formation flight based on directed graph

In this paper, a distributed adaptive cooperative tracking control algorithm is investigated for multi-spacecraft formation flight, in which a directed communication topology is used to characterize the interaction among spacecrafts considering uncertainties of spacecraft moment of inertia and external disturbances. Specifically, for the error dynamics equations of spacecraft described by the Modified Rodriguez Parameters (MRP), a sliding surface including the relative attitude errors and absolute attitude errors is designed. Then, a nonregressor-based adaptive control approach is presented to deal with the model uncertainties and external disturbance such that all of spacecrafts in the formation converge to the desired attitude cooperatively. Finally, an illustrative example is conducted to demonstrate the effectiveness of the proposed algorithm.