A real-time cable force identification method based on improved s-transform

Abstract

The invention discloses a real-time cable force identification method based on the improved S-transform. The method introduces synchronous compression transformation on the basis of the improved S-transform of the window function, so that the cable force can be identified more accurately. The specific implementation includes the following steps: First, input the vibration time-domain signal of the cables of the cable-stayed bridge collected under environmental excitation, and then select the appropriate window function control factor to perform an improved S-transformation on the input time-domain signal, and then transform the transformed The time-frequency planar signal is subjected to synchronous compression transformation to obtain a high-resolution time-spectrum diagram. Finally, the real-time vibration frequency curve of the cable is extracted from the spectrum diagram, and the real-time cable force identification is completed by using the vibration method of cable force measurement combined with the real-time vibration frequency. This method not only retains the advantages of wide applicability and high resolution of S-transform, but also improves the local recognition accuracy in a targeted manner. It is a high-performance cable force recognition method.

Description

technical field

[0001] The invention relates to the field of bridge structure health monitoring, in particular to a real-time cable force identification method based on improved S transform. Background technique

[0002] As an important national infrastructure, bridges are an important part of transportation routes. Cable-stayed bridges are widely used in bridge construction due to their advantages of good mechanical performance, large span and beautiful appearance. The stay cable is one of the main stress components of the cable-stayed bridge. The health monitoring of the stay cable, especially the identification and estimation of the cable force, is very important for the maintenance and safety assessment of the cable-stayed bridge.

[0003] At present, the cable force measurement methods of cable-stayed bridges mainly include: oil pressure gauge reading method, pressure sensor method, magnetic flux method, vibration method, etc. Among them, the vibration method is easy ...

Examples

Embodiment 1

[0082] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

Embodiment

[0084] Taking the simulated synthetic signal as an example, the sampling frequency is 100Hz, and the number of sampling points is N=1024. The analytical formula is:

[0085]

[0086] According to the processing method of the present invention, the simulated synthetic signal is input on the MATLAB software platform, such as figure 2 As shown, the time-domain signal of the cable-stayed bridge cable vibration collected under the excitation of the simulated environment. First, do S-transform on the signal, and the obtained time-spectrogram is as follows image 3 shown; then take γ GST = 0.1, Increase the front taper of the window function, and the obtained time-spectrogram is as follows Figure 4 show; will and After replacing the position of , the back taper of the window function can be increased accordingly, and the obtained time-spectrogram is as follows Figure 5 shown. Will Figure 4 and Figure 5 and image 3 It can be seen from the comparison that the impr...

technical field

[0001] The invention relates to the field of bridge structure health monitoring, in particular to a real-time cable force identification method based on improved S transform. Background technique

[0002] As an important national infrastructure, bridges are an important part of transportation routes. Cable-stayed bridges are widely used in bridge construction due to their advantages of good mechanical performance, large span and beautiful appearance. The stay cable is one of the main stress components of the cable-stayed bridge. The health monitoring of the stay cable, especially the identification and estimation of the cable force, is very important for the maintenance and safety assessment of the cable-stayed bridge.

[0003] At present, the cable force measurement methods of cable-stayed bridges mainly include: oil pressure gauge reading method, pressure sensor method, magnetic flux method, vibration method, etc. Among them, the vibration method is easy ...

Examples

Embodiment 1

[0082] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

Embodiment

[0084] Taking the simulated synthetic signal as an example, the sampling frequency is 100Hz, and the number of sampling points is N=1024. The analytical formula is:

[0085]

[0086] According to the processing method of the present invention, the simulated synthetic signal is input on the MATLAB software platform, such as figure 2 As shown, the time-domain signal of the cable-stayed bridge cable vibration collected under the excitation of the simulated environment. First, do S-transform on the signal, and the obtained time-spectrogram is as follows image 3 shown; then take γ GST = 0.1, Increase the front taper of the window function, and the obtained time-spectrogram is as follows Figure 4 show; will and After replacing the position of , the back taper of the window function can be increased accordingly, and the obtained time-spectrogram is as follows Figure 5 shown. Will Figure 4 and Figure 5 and image 3 It can be seen from the comparison that the impr...

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