Sparse representation method for dynamic load identification of mechanical structure

Abstract

The present invention discloses a sparse representation method for dynamic load identification of a mechanical structure for solving ill-posed natures of the dynamic load identification inverse problem and overcoming the disadvantage that the number of primary functions is required to be determined in advance by a current function approximation method. The sparse representation method comprises the following steps of (1) measuring a frequency response function between an action point of dynamic load of the mechanical structure and a response point of the mechanical structure by using a hammering method, and obtaining a transfer matrix through processing; (2) measuring a response signal generated by the dynamic load acting on the mechanical structure; (3) selecting primary functions to construct a sparse representation dictionary according to morphology of the dynamic load; (4) constructing an L1-norm-based sparse representation model of the dynamic load identification; (5) solving the sparse representation model of the dynamic load identification, and obtaining dynamic load sparse representation coefficient vectors; and (6) obtaining the identified dynamic load. Impact and harmonic load acting on the mechanical structure can be effectively identified, and compared with a traditional Tikhonov regularization method based on L2 norm, the sparse representation method has the advantages that identification precision is high and stability is high.

Description

technical field [0001] The invention belongs to the field of vibration source identification of mechanical structures, and in particular relates to a sparse representation method for dynamic load identification of mechanical structures. Background technique [0002] Dynamic load identification plays a key role in dynamic optimization design, reliability analysis, acoustic vibration transmission path analysis, active and passive vibration control, mechanical fault diagnosis and structural health monitoring and other fields. Dynamic load identification of mechanical structure is the inverse process of dynamic response analysis of vibration system. There are two main ways to obtain the dynamic load, namely direct measurement method and indirect identification method. The process of directly measuring the dynamic load of a structure with a force sensor is the most intuitive, but its obvious defect is that in the actual operation process, on the one hand, it requires a certain s...

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Problems solved by technology

Function approximation methods for identifying loads have the disadvantages of requiring a predetermined number of basis functions and involving matrix inversion operations

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