Bridge natural vibration mode acquisition method based on MIMO radar

Abstract

The invention discloses a bridge natural vibration mode acquisition method based on an MIMO radar. The bridge natural vibration mode acquisition method comprises the steps of: carrying out static clutter suppression on a plurality of continuous frames of scene imaging results to obtain a group of time phase sequences corresponding to each pixel point, and acquiring a scene vibration region distribution diagram through vibration detection; respectively adopting an MUSIC algorithm and a least square estimation algorithm to obtain estimated values of the vibration frequency and the vibration amplitude of the vibration region; carrying out connected domain analysis on the basis of the vibration amplitude diagram to obtain a bridge body mark in the image; and finally, rotating the bridge body,counting the amplitude of the bridge body in the extending direction, and fitting to obtain a bridge body vibration mode curve. According to the bridge natural vibration mode acquisition method, the vibration distribution diagram of the whole scene can be obtained on the premise of not contacting a to-be-detected building or bridge body, and a more accurate vibration mode curve is obtained by extracting the amplitude information of each position of the bridge body, so that a concise, efficient and accurate measurement method is provided for bridge body vibration information acquisition and self-vibration mode detection.

Description

technical field [0001] The invention belongs to the technical field of MIMO radar, and in particular relates to a method for acquiring the natural vibration mode of a bridge based on MIMO radar. Background technique [0002] Structural damage identification based on dynamic characteristic analysis is one of the main contents of bridge health monitoring. By analyzing the dynamic characteristic parameters of the bridge body, the structural damage can be identified and the structural health status can be evaluated. The natural vibration mode analysis is an effective method to identify the defects of the bridge foundation or pier. Existing methods to obtain the natural vibration mode of the bridge body include finite element modeling of the bridge body to obtain the actual vibration mode, and methods such as using acceleration and other point measurement sensors to obtain the mode shape parameters of some nodes of the bridge body and perform fitting. Among them, the finite elem...

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Problems solved by technology

[0005] In view of this, the present invention provides a bridge natural vibration mode acquisition method based on MIMO radar, which can solve the problem that the traditional real aperture radar cannot analyze the vibration mode shape of the bridge body and the detection information of the traditional acceleration sensor is limited, and obtain the natural vibration mode of the bridge body. Mode shape

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