A Local Nonlinear Factor Location Detection Method Based on Nonlinear Separation

Abstract

The invention discloses a local nonlinear factor location detection method based on nonlinear separation. Firstly, a low excitation level vibration test is performed on the nonlinear mechanical structure, the dynamic response of the structure is measured, and the linear frequency response between the excitation position and each detection position is calculated. function, the unit impulse response function is obtained by inverse Fourier transform; high excitation level vibration test is carried out on the nonlinear mechanical structure, and the linear response caused by the excitation force at each detection position is calculated according to the transfer equation of the excitation force and the linear response, combined with the non-linear The linear separation equation separates the nonlinear response caused by the nonlinear force; according to the obtained nonlinear response at the excitation position, the regularization method is used to solve the transfer equation of the nonlinear force and the nonlinear response, and the virtual Non-linear force, and calculate the positioning detection index at each detection position; realize the recognition of the nonlinear position according to the difference of the positioning detection index value corresponding to each detection position.

Description

technical field [0001] The invention belongs to the field of nonlinear system identification, and relates to a local nonlinear factor location detection method based on nonlinear separation. Background technique [0002] In order to promote mechanical equipment towards the goal of high precision, high efficiency, high reliability and long life, especially for fields such as aviation, aerospace and ordnance that require high precision and stability of mechanical equipment, some parts of mechanical equipment Non-linear factors are getting more and more attention. [0003] Nonlinear system identification refers to the use of related technologies to determine the inherent characteristics and key parameters of nonlinear systems according to the principle of objective optimization under the premise of known input and output information. means. Nonlinear system identification helps to understand the local nonlinear characteristics in mechanical structures, and provides a basis fo...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a local nonlinear factor positioning detection method based on nonlinear separation, which solves the calculation amount of positioning detection when there are many nonlinear numbers and nonlinear types in the mechanical structure in the prior art Larger, and the fitting error will also increase accordingly, which is prone to the problem of nonlinear position misjudgment

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