A method and system for dynamic calibration of high-frequency base balance applicable to underdetermination

Abstract

The invention discloses a high-frequency base balance dynamic calibration method and system applicable to underdetermined conditions. The method includes the following steps: calculating the power spectral density of the input measurement signal; selecting and generating signal distortion according to the signal characteristics of the power spectral density frequency interval; select the wavelet basis function and information cost function; determine the number of wavelet packet decomposition layers according to the sampling frequency and frequency interval of the measurement signal; perform wavelet packet decomposition on the measurement signal; reorder the wavelet nodes; according to the selected frequency Interval calculation needs to modify the wavelet node; modify the wavelet coefficient of the selected wavelet node; reassemble the wavelet coefficient; obtain the corrected aerodynamic load time history according to the wavelet packet reconstruction. This method aims at the load correction problem under the underdetermined condition that the existing methods have not covered. Based on the wavelet analysis, the modified wavelet decomposition coefficient is reconstructed by wavelet to achieve the purpose of limited suppression of the aerodynamic distortion signal.

Description

technical field [0001] The invention belongs to the technical field of instrument calibration, and in particular relates to a dynamic calibration method and system for a high-frequency base balance that can be used in underdetermined situations. Background technique [0002] In the existing field of instrument calibration, the high-frequency base force balance (HFFB) technology is widely used in the wind resistance test research of super high-rise buildings due to its simple model making and short test period. In order to ensure that the aerodynamic load power spectrum has a larger bandwidth, it is usually necessary to correct the measured load spectrum before applying the measured data to eliminate the dynamic amplification effect of the BMS to obtain the aerodynamic power spectral density with a wider frequency band. [0003] Existing methods in this field mainly include: [0004] Method 1: single-mode correction; method 2: fixed mode shape correction; method 3: linear ap...

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Problems solved by technology

[0005] The natural frequency and damping ratio of the BMS identified by method 1 using the conventional tapping method cannot reflect the influence of wind-structure interaction (WSI). This problem also exists in method 2. Ignoring the WSI effect will cause the natural frequency of BMS, especially the modal The error in the identification of the damping ratio will affect the correction effect of the measurement signal at the cross-formant, resulting in the inability to effectively correct the signal across the formant; Method 2 uses a preconceived method to assume the mode shape of the BMS, which is equivalent to thinking that Assuming the signal separation matrix of BMS, this method obviously violates the basic principle of parameter identification. When the assumed mode shape does not match the mode shape of the actual model, it will affect the separation effect of the signal, and then affect the natural frequency and damping ratio. Correctly identified, so that the signal cannot be effectively corrected across the formant; method 3 is only a rough approximation when no reasonable solution is found

Although method 4 makes up for the deficiencies of the above three methods, it is only suitable for aerodynamic load correction of positive or overdetermined problems

In addition, none of the above four methods can obtain the time history of the corrected aerodynamic signal

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