Data-driven identification approach for thrusters misalignment angles of rigid satellite

The problem of thruster misalignment angles identification on-line and in real-time is addressed in this study. A data-driven approach is proposed to identify the parameter of satellite's thruster misalignment angles. The satellite considered is represented by Euler angles. As the finite available data is met for on-orbital satellite, the proposed approach is designed by using the techniques of nonlinear observer and data-driven solution simultaneously. As a stepping stone, a terminal slidingmode observer is developed to estimate the deviation torque introduced by thruster misalignment. It is shown by Lyapunov stability analysis that, precise estimation with zero error is guaranteed with finite-time convergence. Based on such estimated value, a data-driven solution is then synthesised to identify the misalignment angles of the thruster. The performance using the proposed identification methodology is evaluated through a numerical example.