Identification of Coefficients in Coupled Heave and Pitch Equations with Forward Speed Effects

摘要

The linearly coupled equations governing the heave and pitch motions of a ship contain coefficients that depend on its forward speed. Different theoretical approaches, such as the energy-formulation and strip-theory approaches, lead to different forms of this dependence. A methodology is proposed for the identification of these coefficients and the determining of the correct form of the dependence of these coefficients on the forward speed. We generate ship- motion data with the Large Amplitude Motions Program (LAMP) and utilize the Eigensystem Realization Algorithm (ERA) to identify the linear coefficients.