Simple model-free attitude control design for flexible spacecraft with prescribed performance

In this paper, a model-free attitude control approach is proposed for the spacecraft in the presence of external disturbances and flexible vibrations with both complexity and performance concerns. By utilizing prescribed performance and backstepping techniques, the controller is constructed in a simple form without requiring any relevant information of the attitude control system dynamics. Moreover, fuzzy/neural network approximations, observers, or adaptive laws are not adopted into the control design, so that the related problems introduced by these estimation structures can be avoided. Numerical simulations in different cases show that the control system can obtain quick and smooth dynamic process and expected tracking accuracy despite the influence of disturbances and flexible vibrations, which demonstrates the effectiveness of the proposed scheme. Owing to the above good features, it is suitable for practical engineering.