High-frequency base balance power calibration method and system for underdetermined conditions

Abstract

The invention discloses a high-frequency base balance power calibration method and system for underdetermined conditions. The method comprises the following steps of: calculating the power spectral density of an input measurement signal; selecting a frequency interval for generating signal distortion according to the signal characteristics of the power spectral density; selecting a wavelet basis function and an information cost function; determining a wavelet packet decomposition layer number according to the sampling frequency and the frequency interval of the measurement signal; performing wavelet packet decomposition on the measurement signal; reordering the wavelet nodes; calculating wavelet nodes needing to be modified according to the selected frequency interval; modifying the wavelet coefficient of the selected wavelet node; reassembling the wavelet coefficients; and reconstructing according to the wavelet packet to obtain a corrected aerodynamic load time history. Aiming at the problem of load correction under the underdetermined condition which is not involved in the existing method, the method is based on wavelet analysis, wavelet reconstruction is carried out on a modified wavelet decomposition coefficient, and the purpose of finite suppression on aerodynamic distortion signals is achieved.

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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