A time-varying linear structure working mode parameter identification method, device and application

Abstract

The invention relates to a time-varying structure working modal parameter identification method based on limited memory principal component analysis, which can only use non-stationary vibration response signals for dynamic systems with time-varying structural characteristics to identify working modal parameters and identify the structure The working mode parameters can effectively monitor the dynamic characteristics of the system in real time, and can be used for vibration control, equipment fault diagnosis, health monitoring, and system structure analysis and optimization. This method only recognizes the parameter characteristics of the system by the measured response signal, without measuring the load signal, and it is proved from mathematical theory analysis and experiment, giving the method a physical meaning. The present invention also relates to a working mode measurement device based on the above method, which measures the vibration response signal and identifies the working mode parameters, obtains the real-time online dynamic characteristic changes of the system structure, and uses it for large complex engineering structures (bridges, Rails, etc.) in fault diagnosis and health monitoring analysis.

Description

technical field [0001] The present invention relates to a time-varying linear structural working modal parameter identification method based on limited memory principal component analysis, and the application of the method in structural fault diagnosis and health state monitoring, and also relates to a time-varying linear structure based on limited memory principal component analysis. A variable linear structure working mode parameter identification device. Background technique [0002] The analysis of vibration characteristics of structures is highly valued in the fields of aerospace vehicles, submarines, civil engineering, ships, automobiles, etc., especially the modal analysis. Modal analysis provides an effective way to study various vibration characteristics. Accurate identification of modal parameters (modal frequency, mode shape, damping ratio) is an important guarantee for the safety and maintainability of the system structure, and an important method for structural...

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Problems solved by technology

Scholars at home and abroad have also done a lot of research on this problem. For example, McLamore et al. used the peak method to extract the modal frequency based on the fast Fourier transform, but this method has the problem of not being able to identify dense modes; the subspace method proposed by Kalman et al. , using matrix decomposition and other methods to extract the signal subspace to obtain an equivalent system, this method is suitable for parameter identification of linear time-varying structures under stationary excitation, and has a certain anti-interference ability to output noise, but the determination of the order of the stochastic subspace model It is relatively cumbersome, with a large amount of calculation, and it is easy to identify false modes; there are also methods such as wavelet transform and Hilbert-Huang transform based on time-frequency analysis, which analyze signal characteristics from both time domain and frequency domain, but these methods are a It is difficult to make a complete analysis of the overall characteristics of the system, and for dense mode problems, due to the limitation of filtering ability, the recognition accuracy is easily affected

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