连续小波变换在船舶横摇阻尼识别中的应用

考虑到静水横摇衰减试验信号具有有效样本周期较少和信号周期随幅值发生变化等特点,为了高精度地识别船舶横摇阻尼的大小,采用Morlet小波作为连续小波变换的基函数,探讨有效克服边界效应的处理方法,在时频平面内通过相位特性提取小波脊线,并依据小波脊线的幅值和幅角变化规律识别出横摇阻尼参数.通过仿真实例验证该方法的可行性,同时也为船舶横摇阻尼试验提供一种新的识别方法.

Application of Continuous Wavelet Transform in the Identification of Ship Roll Damping

The still water roll damping test signal has the characteristics of low valid sample cycle and signal cycle changes with amplitude. In order to identify the size of the ship roll damping with high precision, the Modet wavelet was taken as the pri- mary function of continuous wavelet transform to study the effective processing method to overcome boundary effect. The phase characteristic was used to extract the wavelet ridge line in the time-frequency plane, to identify the roll damping parameters ac- cording to the change rule of wavelet ridge line＇s amplitude and amplitude. Simulation example proved the feasibility of this method.