摘要
针对多重同步挤压变换及其改进算法存在估算瞬时频率精度不高的问题,提出新的高阶多重同步挤压变换算法并应用于时变结构的瞬时频率识别。该方法首先通过引入高阶瞬时振幅与相位得到精度更高地估算1阶瞬时频率,然后采用递推法得到估算的高阶瞬时频率。其次,对高阶瞬时频率进行多次迭代并对迭代后的瞬时频率进行重排,从而得到高阶多重同步挤压变换后的瞬时频带。再次,运用时频系数模局部极大值法在限定的频带范围内提取瞬时频率曲线。通过两组数值算例和一个质量突变的悬臂梁试验验证所提新方法的有效性,研究结果表明:相比现有的多重同步挤压变换改进算法,高阶多重同步挤压变换不仅具有较好的精度,而且可以减少未重排点。
In order to solve the problem that the multi-synchrosqueezing and its improved algorithms cannot estimate instantaneous frequency accurately,a new method called high-order multi-synchrosqueezing transform(HMSST)is proposed to identify the instantaneous frequency of time-varying structures.In this method,the high order phase and amplitude are introduced at first to obtain more accurate instantaneous frequency.Then,the high order instantaneous frequency is estimated by recursive algorithm.Afterwards,multiple iterations are applied to the obtained high order instantaneous frequencies and the instantaneous frequencies after the iteration are rearranged so as to get a refined frequency band.Finally,the instantaneous frequency curve is extracted within the limited range of the refined frequency band using the local maxima of time-frequency coefficient modulus.Two numerical cases and an aluminum cantilever beam test with abrupt mass reduction are investigated to verify the effectiveness of the proposed method.The results demonstrate that the proposed HMSST behaves better than current improved multi-synchrosqueezing transform.It not only has the higher accuracy of instantaneous frequency estimation,but also reduces non-reassigned points in the refined frequency band.
作者
李宇祖
刘景良
骆勇鹏
盛叶
LI Yuzu;LIU Jingliang;LUO Yongpeng;SHENG Ye(School of Transportation and Civil Engineering,Fujian Agriculture and Forestry University,Fuzhou 350002,China;“Digital Fujian”Laboratory of Internet Things for Intelligent Transportation Technology,Fujian Agriculture and Forestry University,Fuzhou 350002,China)
出处
《噪声与振动控制》
CSCD
北大核心
2023年第2期43-50,共8页
Noise and Vibration Control
基金
国家自然科学基金青年基金资助项目(51608122)
福建省自然科学基金面上资助项目(2020J01581,2020J01579)
福建农林大学科技创新专项基金资助项目(CXZX2020112A)
福建省林业科技资助项目(闽林科(2020)29号)
福建农林大学优秀硕士学位论文资助基金资助项目(113/1122YS01005)。
关键词
振动与波
时变
多重同步挤压变换
未重排点
频带
瞬时频率
vibration and wave
time-varying
multi-synchrosqueezing transform
non-reassigned point
frequency band
instantaneous frequency
