Fast Finite-time Attitude Tracking Control of Rigid Spacecraft with Quantized Input Signals

The problem of fast finite-time attitude tracking quantized control is addressed for rigid spacecraft in the paper. With the help of the backstepping technique, hysteresis quantizer and the finite-time control scheme, a novel fast finite-time attitude controller is proposed. The modified Rodriguze parameters (MRPs) are used to describe the dynamic and kinematic equations of rigid spacecraft system. Then by utilizing Lagrange theorem, rigid spacecraft attitude system is transformed into a common strict feedback system. Next, a new coordinate transformation is introduced, which will be used in the presented controller. Based on the backstepping strategy, the sufficient conditions for the existence of the fast finite-time controller are presented. Theoretical analysis shows that the attitude tracking errors rapidly converge to the equilibrium point within finite time. Meanwhile, all the signals of the close-loop system are bounded. Simulation results demonstrate the effectiveness of the proposed approach.