Fault-tolerant adaptive finite-time attitude synchronization and tracking control for multi-spacecraft formation

This paper addresses the attitude synchronization and tracking control (ASTC) for multi-spacecraft formation system (MFS) under undirected and directed graph. First, a new adaptive nonsingular fast terminal sliding mode surface (ANFTSMS) is developed. It has both the merits of the NFTSM avoiding singularity and the adaptive method regulating the relative weighting of parameters. This provides designers a new way to improve the control performance. Second, by applying ANFTSMS, the proposed ANFTSM-controllers (ANFTSMCs) provide high precision finite-time convergence, robust to time-varying disturbances, uncertainties and accommodate to actuator faults, limited inputs. Moreover, the ANFTSMCs also achieve simple structure, inexpensive computations and chattering-free for continuous design. Few studies have addressed these problems simultaneously. Finally, effectiveness of the algorithms are verified via simulations.