Adaptive sliding mode control scheme for satellite detumbling using flexible rod with improved dynamic model

Space debris removal, especially malfunctioning satellites, has become increasingly critical with the rise in space launches. A major challenge is the uncontrollable spin of malfunctioning satellites due to residual momentum, which complicates capture and deorbiting efforts. This study proposes a detumbling approach using a Detumbling Satellite (DS) equipped with a flexible rod, addressing the difficulties associated with large rod deformations, contact dynamics, and control. Although the Absolute Nodal Coordinate Formulation (ANCF) has been effective for large deformations, further studies are needed to achieve more accurate contact dynamics and robust control. Furthermore, severe impulsive disturbances caused by contact processes make it difficult for existing controllers to meet the demand for strong robustness, high accuracy, and quick convergence. Therefore, this work uses modified Leuven friction model, which offers clear advantages over the Coulomb friction model, along with a dissipative contact force model, for improved accuracy in force prediction. To counteract impulsive disturbances arising from contact interactions, an Adaptive Sliding Mode Control (ASMC) strategy is designed to stabilize DS attitude. A boundary layer thickness is incorporated to mitigate chattering effects. The simulation results show that the proposed scheme is capable of detumbling a malfunctioning satellite in 437 s to an acceptable range. Other simulations validate the effectiveness of the improved dynamic model and the proposed ASMC controller. This research advances space debris removal by improving the precision and robustness of detumbling strategies, with significant implications for satellite servicing and sustainable space operations.