Robust Adaptive Control for Micro-Vibration Suppression under Multiple Unknown Narrow-Band Disturbances

Abstract While the Youla–Kučera (Y–K) parameterization can suppress unknown and time-varying narrow-band disturbances, its performance depends heavily on an accurate secondary-path model, which is often difficult or impossible to obtain in practice. To address this limitation, this work proposes a direct feedback robust adaptive micro-vibration control algorithm that does not rely on secondary-path identification. The controller integrates the Y–K framework with a variable step-size LMS (VSSLMS) scheme for real-time parameter adaptation, ensuring closed-loop stability while improving convergence and robustness under multi-frequency time-varying disturbances. Experiments on an active micro-vibration platform show that the proposed method achieves over 60% improvement in steady-state suppression compared with conventional FxLMS and Y–K + LMS algorithms, particularly under dual-frequency disturbances with spectrum and amplitude variations. These results demonstrate that the method provides a model-independent and robust solution for micro-vibration suppression in precision satellite systems.