基于改进EMD分解的时变结构密集模态的瞬时参数识别

摘要: 提出基于改进经验模态分解（EMD分解）识别含有密集模态的时变结构的瞬时参数的方法。通过波组信号前处理和正交化经验模态分解方法（OEMD）解决传统的EMD无法分解2个近频模态的固有模态函数（IMF）和IMF分量之间不正交这两个问题，将该方法应用于时变结构密集模态的瞬时参数的识别中，给出基于此方法识别时变结构密集模态参数的步骤，并通过一个含有密集模态的3自由度时变结构算例验证了该方法的正确性、有效性以及识别密集模态的优势。
- 改进经验模态分解 /
- 波组 /
- 正交化经验模态分解 /
- 时变结构 /
- 密集模态
Abstract: In identifying the parameters with the empirical mode decomposition (EMD) method, there exists the deficiency of the mode separation of two intrinsic mode function (IMF) components with near frequency and the non-orthogonality between IMF components, which make the parameters identification results not accurate and stable enough. To solve these problems, we propose the improved EMD method which combines the wave group(WG) signal processing method with the orthogonal empirical mode decomposition(OEMD). Based on the improved EMD method, the parameter identification procedures for time varying structures with closely spaced modes are proposed and applied to the numerical simulation with a three degrees-of-freedom time varying dynamic model. The simulation results demonstrate that the proposed method has very good effectiveness, efficiency and has the advantages of identifying the parameters of time varying structures with closely spaced modes.
- closely spaced mode /
- identification (control systems) /
- improved EMD method /
- orthogonal empirical mode decomposition /
- time varying structures

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参考文献(13)

[1]	邹经湘,于开平,杨炳渊.时变结构的参数识别方法[J].力学进展,2000,30:370-377 Zou J X, Yu K P, Yang B Y. Methods of time-varying structural parameter identification[J]. Advances in Mechanics, 2000,30:370-377 (in Chinese)
[2]	许鑫,史治宇,Staszewski W J,等.基于加速度响应连续小波变换的线性时变结构瞬时频率识别[J].振动与冲击,2012,31(20):166-171 Xu X, Shi Z Y, Staszewski W J, et al. Instantaneous frequencies identification of a linear time-varying structure using continuous wavelet transformation of free decay accleration response[J]. Journal of Vibration and Shock, 2012,31(20):166-171 (in Chinese)
[3]	李会娜,史治宇.时变系统的物理参数识别[J].振动工程学报,2007, 20(4) Li H N, Shi Z Y. Physical parameter identification of time-varying system[J]. Journal of Vibration Engineering, 2007,20(4) (in Chinese)
[4]	许鑫,史治宇,龙双丽.基于小波状态空间法的时变结构瞬时频率识别[J].中国机械工程,2011,22(8):901-904 Xu X, Shi Z Y, Long S L. Instantaneous frequency identification of a time-varying structure using wavelet-based state space method[J]. China Mechanical Engineering, 2011,22(8):901-904 (in Chinese)
[5]	Huang N E, Shen Z, Long S R, et al. The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis[J]. Proceedings of the Royal Society A, 1998,454:903-955
[6]	Huang N E, Shen Z, Long S R. A new view of nonlinear water waves: the hilbert spectrum[J]. Annual Review of Fluid Mechanics,1999,31:417
[7]	Yang J N, Lei Y, Pan S, et al. System identification of linear structures based on hilbert huang spectral analysis. part 1:normal modes[J]. Earthquake Engineering and Structural Dynamics, 2003,32:1443
[8]	陈隽,徐幼麟.HHT方法在结构模态参数识别中的应用[J].振动工程学报,2003,16(3) Chen J, Xu Y L. Application of HHT for modal parameter identification to civil structures[J]. Journal of Vibration Engineering, 2003,16(3) (in Chinese)
[9]	付春,姜绍飞,牟海东.基于改进HHT的结构模态参数识别方法[J].应用基础与工程科学学报,2011,19(4) Fu C, Jiang S F, Mou H D. Structural modal parameter identification method based on improved hilbert-huang transform[J]. Journal of Basic Science and Engineering, 2011,19(4) (in Chinese)
[10]	Shi Z Y, Law S S, Xu X. Identification of linear time-varying MDOF dynamic systems from forced excitation using Hilbert transform and EMD method[J]. Journal of Sound and Vibration, 2009,321(3-5):572-589
[11]	Shi Z Y, Law S S. Identification of linear time-varying dynamical systems using Hilbert transform and EMD method[J]. Journal of Applied Mechanics, 2007,74(2):223-230
[12]	Wang W. Decomposition of wave groups with EMD method[C]// The Hilbert-Huang Transform in Engineering, 2005
[13]	楼梦麟,黄天立.正交化经验模式分解方法[J].同济大学学报,2007,35(3):293-298 Lou M L, Huang T L. Orthogonal empirical mode decomposition[J]. Journal of Tongji University, 2011,19(4) (in Chinese)