Dynamic calibration method for high-frequency force balance

Abstract

The invention discloses a dynamic calibration method for a high-frequency force balance, which comprises the steps of performing whitening on a measurement signal x(t) to acquire a whitened signal z(t); seeking an orthogonal matrix V, enabling the whitened signal z(t) to equal to Vq(t), and thus acquiring a separated signal q(t); performing natural frequency and modal damping ratio recognition on the separated signal in modal coordinates; correcting the separated signal according to recognized parameters; and inversely deducing according to the separated signal to acquire a corrected pneumatic load. According to the invention, separation is performed on a coupling signal, and for independent components acquired by separation, natural frequency and modal damping ratio recognition is performed on the separated signals one by one by adopting a curve fitting method through combining aerodynamic characteristics, so that a dynamic amplification effect of a modal coupling system is corrected and eliminated, a real aerodynamic load spectrum density matrix is acquired finally, the reliability of parameter recognition and corresponding HFFB (High-Frequency Force Balance) dynamic signal calibration can be improved to the maximum extent, and an important basis is laid for subsequent accurate estimation for high-rise building prototype wind-induced responses.

Description

technical field [0001] The invention belongs to the technical field of instrument calibration, and in particular relates to a dynamic calibration method of a high-frequency base force balance. Background technique [0002] 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. HFFB belongs to the category of multi-component (usually five-component or six-component) balances. Multi-component balances will have problems of mutual interference or coupling between components to varying degrees. Usually, it is necessary to calibrate before leaving the factory to determine the simulation of each component and the corresponding sensor output. The transformation matrix of the signal finally achieves decoupling. Strictly speaking, this calibration technique is only suitable for static measurement. When the balance is installed on the measured model,...

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Problems solved by technology

[0007] Among the above methods, the BMS natural frequency and damping ratio identified by the conventional tapping method in method 1 cannot reflect the influence of wind-structure interaction (WSI). This problem also exists in method 2. Ignoring the WSI effect will lead to the BMS natural frequency In particular, the error in the identification of the modal damping ratio will affect the correction effect of the measurement signal at the cross-resonance peak, so that the signal cannot be effectively corrected across the resonance region; method 2 uses a preconceived method to assume the mode shape of the BMS, This is equivalent to thinking that the signal separation matrix of the BMS is assumed. This method obviously violates the basic principles 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 the correct identification of the damping ratio, in the end, it is also impossible to effectively correct the signal across the resonance region; method 3 is only a rough approximation when no reasonable solution is found

In summary, the existing methods have a certain positive effect on the correction of the distortion degree of the measured signal within a certain frequency range, but there are still deficiencies.

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