Hydrodynamic Coefficients Identification of Nonlinear Ship Roll Motion based on Hilbert Transform

This paper presents a novel two-step hydrodynamic coefficients identification method to identify the damping and restoring moment coefficients of ship roll motion in irregular waves. The random decrement technique (RDT) is first used to convert the responses into random decrement signatures. Then, a Hilbert transform (HT)-based nonlinear system identification method is used to identify the damping and restoring moment coefficients from the obtained random decrement signatures. Numerical studies were performed on two ship models with simulated data. The results show that the proposed method can successfully identify the hydrodynamic coefficients of roll motion using the vibration responses of ships in irregular waves.