Simulation about the vibration characteristic of a small autonomous underwater v ehicle based on transfer function method

The use of an autonomous underwater vehicle (AUV) has been increasing in scientific, military, and commercial areas due to its autonomous operation without human control for a hazardous mission. Since it is impossible to use the devices with electromagnetic waves for gathering information in an underwater environment, only sonar systems that use sound waves can be used in underwater environments. Since the thruster system is widely used as the propulsion system of an AUV and is mounted on the outside of an AUV’s stern, the thruster system can generate vibration and that vibration can be transferred throughout the shell of the AUV from the stern of AUV to its bow. The transferred vibration can affect the performance of various sonar systems that equip the AUV such as side-scan sonar or forward-looking sonar. Therefore, it is necessary to predict the effect of the transferred vibration of the AUV on the sonar systems. Even if various numerical methods were used to analyze the vibration problem of an AUV, it would be hard to predict the vibration phenomena of an AUV at the initial design stage. In this work, a simulation study was carried out to analyze a vibration feature of a small real AUV in the air. The transfer functions of vibration acceleration based on the simulation results are presented.