Adaptive fuzzy sliding mode attitude control for large angle slew maneuvering of flexible satellite

An adaptive fuzzy sliding mode control was proposed for the attitude stabilization of flexible satellite during large angle slew maneuvering. The dynamic model of the satellite with flexible appendages was derived by Lagrange equation. The sliding mode control was designed to make the state of system reach sliding mode surface in finite time. The adaptive fuzzy system was used to approximate the strong couple nonlinear function between rigid central body and flexible appendage dynamics during large angle slew maneuvering. The sign function was replaced by the saturation function so as to attenuate the chattering phenomena and avoid exciting higher frequency elastic mode. The fuzzy rules were employed to gain the size of boundary layer. Simulation results show that not only attitude stabilization of satellite with high precision is achieved, but also the elastic vibration of flexible appendage is suppressed effectively, and the system is robustness against system uncertainties and environmental disturbances.