Spacecraft attitude control based on quaternion

In this paper, a control approach based on optimal control and finite-time control technology is derived for spacecraft. For the kinematics subsystem, the condition which can guarantee the existence of optimal angular velocity and the explicit expression of optimal angular velocity are proposed. For the dynamics subsystem, a control law is designed such that the optimal angular velocity can be tracked in finite time. The proof of convergence of the close-loop system is also given. The effectiveness of the proposed approach is demonstrated by simulation results.