Fault Tolerant Sliding Mode Control for a Nanosatellite

This paper describes a nanosatellite attitude control being able to perform fault tolerant control to increase a reliability of a nanosatellite. A fault-tolerant sliding mode controller is used for a nanosatellite using four reaction wheels as a set of actuators. The fault-tolerant sliding mode controller is designed to perform the rest-to-rest maneuver of a satellite system. The actuator fault reflects the degradation of the actuation effectiveness. The Lyapunov theorem is used to analyze the system stability. In computer simulations, we use SNUSAT-1 made in Seoul National University as an applied nanosatellite. The control scheme of a nanosatellite is verified under the actuator fault situation that one reaction wheel of four reaction wheels is fault as well as the normal situation that four reaction wheels are healthy.