一种窄带平稳随机过程功率谱的简化拟合方法

基于平稳随机过程的基本原理,建立了拟合窄带平稳随机过程的功率谱所需的成形滤波器的简化模型,推导了窄带平稳随机功率谱的峰值、峰值频率、带宽与成形滤波器相应参数之间的关系,给出了拟合窄带平稳随机过程功率谱的简化方法。应用此方法对美国海军 CVA59航空母舰海上运动的垂荡、纵摇和横荡运动分量的 3个具体的功率谱实例进行了拟合,通过对将实测值与拟合结果进行比较,表明 :这种方法能够很好地拟合典型的对称窄带平稳随机过程,对于对称性不好和带宽较大的的功率谱,拟合的误差相对大一些。

SIMPLIFIED METHOD TO FIT THE POWER SPECTRUM OF NARROW-BAND STOCHASTIC PROCESS

A simplified model of the shape model is established for fitting the power spectrum of a narrow band stochastic process on the basis of principles of the stochastic process. And the relationship of the peak value, peak frequency, bandwidth of a narrow band stochastic process with the corresponding parameters of the shape filter is deduced. Thus a simplified method to fit the power spectrum of the narrow and stochastic process is established. The method is applied to fit the power spectrum of the heave, pitch and sway motion of the CVA59 aircraft carrier at sea. The comparison between fitted results and measured data shows that the combination method works very well, while the fitting error is larger for the spectrum whose symmetry is not so good and bandwidth is larger.