Attitude tracking control model design for rigid spacecrafts based on discrete-time sliding mode

In order to improve the robust performance to parametric perturbations and external environment disturbances for rigid spacecrafts, an attitude tracking controller based on the discrete-time sliding mode control principle is proposed. The spacecraft model is firstly modeled. Considering the time-varying and interfering moments and even disturbances, the system is then decoupled into independent discrete-time subsystems via the input-output feedback linearization. To this end, the discrete-time sliding mode attitude control law is designed from the exponential approach law. Simulation results indicate that the discrete-time control system proposed can ensure the attitude stabilization of rigid spacecrafts while realizing the decoupling control among channels. Moreover, the system is robust to the parametric perturbations and external disturbances and the attitude angle tracking errors can be reduced effectively. In addition, the tracking dynamic characteristics and the sampling period are validated for the system considered. ©, 2015, Harbin Institute of Technology. All right reserved.