A fuzzy-neural network sliding mode control for flexible spacecraft

A fuzzy-neural network sliding mode control (FNNSMC) is proposed for the attitude stabilization of flexible spacecraft during large angle slew maneuver. The dynamic model of the spacecraft with flexible appendages is derived by Lagrange equation. To make the system state reach sliding mode surface in finite time, a sliding mode controller is designed, so the system is robustness against uncertainties and disturbances during the sliding phase. A fuzzy-neural network system is used to approximate the strong coupling nonlinear dynamics between rigid hub and flexible appendages, so that the elastic vibration of flexible spacecraft during maneuver is suppressed and the attitude of flexible spacecraft is stabilized. Simulation results show that not only high-precision attitude stabilization of flexible spacecraft is achieved, but also the elastic vibration of flexible spacecraft during maneuver is suppressed effectively.