Vibration monitoring method

Abstract

The invention discloses a vibration monitoring method. The vibration monitoring method comprises the following steps of 1, selecting a tip of a blade as a reference point of vibration, and aligning a lens of an image acquisition device with the reference point to obtain a vibration image; 2, decomposing the vibration image into frames, and preprocessing each frame to eliminate noise; 3, selecting the pixel coordinates of the reference point in each frame, converting the pixel coordinates, recording the converted pixel coordinates of the reference point, and drawing a relational graph of the converted pixel coordinate values and the time t; and 4, performing curve fitting on the relational graph, and performing Fourier transform on a fitted curve f (t) to obtain F (omega). The image acquisition device is placed on a fairing, and the angle is adjusted to align to the reference point of the blade to be monitored, so that the definition of the acquired image is ensured, and the image can be acquired in real time; and by adopting the method, the relational graph of the pixel coordinate values and the time t is drawn, and the composition and proportion of the vibration frequency omega are obtained through fitting and Fourier transform.

Description

technical field [0001] The invention relates to the technical field of wind power generation, and more specifically, relates to a vibration monitoring method. Background technique [0002] The blade is a key component of the wind turbine, accounting for about 20% of the manufacturing cost of the entire wind turbine. During operation, the blade will be continuously impacted by alternating loads such as aerodynamic force and inertial force, resulting in irregular vibration and even out of shape. If the vibration is abnormal or the deformation of the blade is too severe, it will cause damage to the blade and cause huge economic losses. Therefore, it is particularly important to monitor the vibration status of fan blades in real time. [0003] Research on the vibration monitoring of wind turbine blades has attracted attention. As far as existing technologies are concerned, they are mainly divided into contact methods and non-contact methods. Most of the former use piezoelectr...

AI Technical Summary

Problems solved by technology

[0004] However, as far as the current research status is concerned, the machine vision method has not been practically applied to the vibration monitoring of wind turbine blades, because the image acquisition of blades and the calculation of vibration frequency are the difficulties of research.

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