Abstract: A mobile satellite communication system is installed on a moving carrier for satellite communication. The tracking and stabilizing problem of the mobile satellite communication system is studied in this paper. The triaxis nonlinear model of the mobile satellite communication system is chosen as the control object, because it can describe the kinematics and dynamics features of the system more accurately than the singleaxis model.
Based on the actuator dynamic features, a nonlinear robust controller with actuator dynamic compensation is designed. The designed controller can eliminate the disturbances when the carrier is moving and track the target satellite accurately. Because the problem of the actuator dynamics is further considered, the controller is more suitable for the practical application. At last, three sets of comparative simulation results are used to verify the tracking and stabilizing effectiveness of the designed controller under different disturbances.

Key words: Mobile satellite communication system, Nonlinear system, Backstepping, Robust control, Actuator dynamics