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This paper proposes a new adaptive feedforward control method for the rejection of multiple periodic disturbances in the propulsion shafting system. The active vibration control scheme of the propulsion shafting system is established by employing the equivalent-input-disturbance principle which reduces the complexity of the control system in applications. The adaptive control algorithm is designed by taking the scale transformation procedure and the frequency-tracking technique into consideration. The scale transformation normalizes the iso-surface of the optimization function by the frequency response characteristics of the control channel, which immensely improves the convergence rate of the control algorithm for multi-harmonic disturbance. Moreover, the adaptive controller tracks the fluctuating frequencies in a direct method, enhancing the efficiency and robustness of the algorithm for eliminating time-varying disturbances. Finally, numerical simulation and experimental validation are carried out to show that the proposed method has good performance on the application of the active vibration control of the propulsion shafting system. [ABSTRACT FROM AUTHOR]

The effective control of the transverse vibration is critical for the propeller-shaft coupling system, where excessive vibrations may cause reliability problems for working equipment and radiated noise of marine vessels. This paper is concerned with the active control method of reducing the lateral vibration transmission for the propeller-shafting system using a 1:10 scaled ratio experimental model. The lateral vibration characteristics of the propeller-shaft coupling system are investigated first by the experimental method, identifying the propeller mode and shafting modes that dominate the peak frequencies of system responses. The active vibration control system taking the electromagnetic actuator as the control power source and the raft vibration acceleration as the active control target is proposed for base-point control and cross-point control strategies. An adaptive feedforward controller based on the equivalent interference principle is developed by the improved LMS algorithm with parameter scale transformation. The designed adaptive algorithm accelerates the convergence rate of the controller parameters and tracks the unknown frequency fluctuations of the time-varying disturbance. Experimental implementation of the proposed active controller is carried out, demonstrating the applicability of the improved algorithm on the lateral vibration control of the propeller-shafting system. • An experimental model of the propeller-shafting coupling system is proposed. • The lateral vibration characteristics and vibration transmission paths of the coupling model are studied. • The active vibration control system is built considering the base-point and cross-point actuation. • A PST-based adaptive feedforward control algorithm is developed and effective for vibration attenuation. [ABSTRACT FROM AUTHOR]