Spacecraft attitude sliding mode control method design

The control of sliding mode variable structure has become one of an important in the modern control theories. It is also widely concerned by scholars at home and abroad due to its complete robustness such as its perturbation on system parameters, external disturbance and system uncertainty. This paper establishes the mathematical model for spacecraft based on error quaternion, derives the sliding-mode control law based on Lyapunov function by selecting appropriate sliding model and effectively weakens the buffeting by means of boundary layer approach. According to theoretical analysis and system simulation, the sliding-mode controller so designed is provided with robustness and overall stability under circumstances of parameter changes and external disturbances.