基于小波变换的弱非线性阻尼和刚度辨识方法  

Identification of weak nonlinearities in damping and stiffness based on wavelet transform

作　　者：代煜[1] 孙和义[1] 李慧鹏[1] 唐文彦[1] 

机构地区：[1]哈尔滨工业大学自动化测试与控制系,哈尔滨150001

出　　处：《振动与冲击》2009年第2期51-55,共5页Journal of Vibration and Shock

摘　　要：利用脊上连续小波变换系数的幅度和相位,从结构系统的自由衰减响应中辨识了弱非线性阻尼和刚度。提出了一种检测小波脊的新方法以消除连续小波变换幅度极值的频移。为了抑制边界效应,提出利用最小二乘拟合误差选择小波函数参数的优化算法。使用数值仿真和实验检验了辨识方法的精度。实验装置是一台高精度转动惯量测试仪。结果表明提出的方法能够准确的辨识结构中的弱非线性阻尼及刚度参数。Utilizing the magnitide and phase of continuous wavelet transform(CWT) coefficient on ridge,weak nonlinearities in damping and stiffness were identified from the freely decaying response of a structural system.A new algorithm for ridge detection was introduced to eliminate the frequency-shift of the magnitude extreme of CWT.In order to minimize end-effect,the parameter selection of wavelet function was performed by using an optimization technique based on the method of fitting error of least squares.Both numerical and experimental studies were carried out to demonstrate the proposed procedure and verify its accuracy.The tested system is a high accuracy instrument for measuring moment of inertia.The results show the method works very well in identifying weak nonlinearities in damping and stiffness of structures.

关 键 词：参数识别 非线性系统 小波变换 脊 最小二乘法 

分 类 号：O322[理学—一般力学与力学基础]