Research and simulation of vibration transmission control in underwater drone engines

This paper addresses the problem of vibration transmission from the propulsion system to the hull of unmanned underwater vehicles (UUVs), which is one of the primary sources of acoustic radiation and vehicle detectability. Conventional passive vibration isolation methods exhibit limited effectiveness in suppressing low-frequency vibrations generated by rotating machinery. To overcome this limitation, a compact hybrid active-passive vibration isolation mount is proposed, combining a rubber vibration isolator with piezoelectric actuators. To investigate vibration transmission characteristics, a coupled dynamic model of the “vibration source-isolation mount-hull” system was developed using the finite element method (FEM). The parameters of the passive isolator were determined based on stiffness requirements and finite element simulations, while active vibration suppression was implemented through a multichannel MIMO control system employing the adaptive filtered-x least mean squares (Fx-LMS) algorithm. The results demonstrate that the proposed active-passive isolation system effectively reduces vibration transmission within the frequency range of 10-500 Hz. A maximum vibration reduction of 26 dB was achieved, providing significantly better suppression of low-frequency vibrations than conventional passive isolation solutions. The proposed approach can be applied to enhance the acoustic stealth performance of unmanned underwater vehicles and other compact underwater platforms.