Predefined-Time Observer-Based Nonsingular Sliding-Mode Control for Spacecraft Attitude Stabilization

The predefined-time attitude stabilization control problem of a spacecraft with external disturbance is addressed. A predefined-time observer-based control approach is presented using a new nonsingular sliding surface. On this sliding surface, the system states can converge to zero within a predefined time. Moreover, the incorporated disturbance observer is continuous with the chattering phenomenon eliminated. Compared with the existing finite/fixed-time attitude control methods, which need a complex process to determine the settling time, the upper bound of the convergence time ensured by the presented approach is determined by a constant only. Simulation study is further given to confirm that the presented controller is effective.