首页|结合SLMSST和DO提取时变结构瞬时频率

结合SLMSST和DO提取时变结构瞬时频率

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  • 国家科技期刊平台
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  • NSTL
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为提升局部最大同步挤压变换估算瞬时频率的精度，本文结合2阶局部最大同步挤压变换(Second-order Local Maximum Synchrosqueezing Transform，SLMSST)和动态规划(Dynamic Optimization，DO)方法提出一种识别时变结构瞬时频率的新方法。该方法首先通过引入2阶瞬时振幅与相位得到精度更高的2阶瞬时频率估算位置。其次，搜索频率方向上时频系数的局部最大值所对应的2阶瞬时频率位置并根据这些位置对时频系数进行重排，从而得到2阶局部最大同步挤压变换后的瞬时频带。再次，运用动态规划法在限定频带范围内提取瞬时频率曲线。通过一组数值算例和一个时变拉索试验验证了所提新方法的有效性，研究结果表明:相比既有的局部最大同步挤压变换算法，2阶局部最大同步挤压变换和动态规划的联合算法不仅具有较好的精度，而且具有更好的时频聚集性。
Instantaneous Frequency Identification of Time-varying Structures by Combing Second-order Local Maximum Synchrosqueezing Transform and Dynamic Optimization
In order to improve the accuracy of instantaneous frequency identified by local maximum synchrosqueezing transform,a new algorithm is proposed by combining second order local maximum synchrosqueezing transform(SLMSST)and dynamic optimization(DO).In this method,the second order phase and amplitude are introduced at first to obtain more accurate second order instantaneous frequency positions.Then,the local maximum values of the time-frequency coefficients are searched in the frequency direction and the corresponding positions of the second order frequencies are found.According to these positions,the time-frequency coefficients are reassigned to obtain the instantaneous frequency band by the SLMSST.Finally,the dynamic optimization method is applied to extract the instantaneous frequency curve inside the frequency band.A numerical case and a test on a time-varying cable are investigated to verify the effectiveness of the proposed method.The results demonstrate that the proposed method behaves better than local maximum synchrosqueezing transform.It not only enhances the accuracy of instantaneous frequency identification,but also has better time-frequency energy concentration.

vibration and wavetime-varyinglocal maximum synchrosqueezing transformtime frequency coefficientinstantaneous frequencydynamic optimization

李宇祖、刘景良、苏杰龙、吕毓霖

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福建农林大学 交通与土木工程学院,福州 350108

福建农林大学"数字福建"智能交通技术物联网实验室,福州 350108

振动与波 时变 局部最大同步挤压变换 时频系数 瞬时频率 动态规划

国家自然科学基金青年基金福建省自然科学基金面上项目福建省自然科学基金面上项目福建农林大学科技创新专项福建农林大学优秀硕士学位论文资助基金

516081222020J015812020J01579CXZX2020112A113/1122YS01005

2024

10.3969/j.issn.1006-1355.2024.02.009

噪声与振动控制
中国声学学会

噪声与振动控制

CSTPCD北大核心
影响因子：0.622
ISSN：1006-1355
年,卷(期)：2024.44(2)
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