Satellite attitude dynamics are inherently nonlinear, and modelling becomes particularly challenging during large-angle manoeuvres or actuator saturation. Traditional first-principles modelling methods often require precise system parameters, yet even then, many complex behaviours may not be captured. To address this, this paper proposes a data-driven modelling method based on Koopman operator theory, which learns a global linear representation of satellite attitude dynamics from simulated trajectory data. Specifically, the model constructs a high-dimensional enhanced state space using a set of observable values, enabling the Koopman model to approximate nonlinear dynamics through linear systems. This approach achieves a relatively accurate prediction of angular velocity and attitude trajectories. Simulation results show that the Koopman-based model is effective and can be applied for real-time attitude prediction and satellite control.
Research Article
Open Access