Vibration monitoring method based on image acquisition

Abstract

The invention discloses a vibration monitoring method based on image acquisition, and the method comprises the steps: 1, selecting the tip of a blade as a vibration reference point, and enabling a lens of an image acquisition device to be aligned with the reference point, so as 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 relation graph, and performing Fourier transform on a fitted curve f (t) to obtain F (omega). The image acquisition device is placed on the hub, 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, a 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 present invention relates to the field of wind power generation, and more particularly to a vibration monitoring method based on image acquisition. 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 continue to be impacted by an altered load of aerodynamic, inertial force, resulting in irregular vibrations or even Deformation. If the vibration is abnormal or the blade shape is too intense, it will lead to huge economic losses in the damage of the blade. Therefore, it is especially important to monitor the vibration status of the fan blade in real time. [0003] Studies on the vibration monitoring of wind turbine leaves have attracted attention, and in terms of prior art, it is mainly divided into contact methods and non-contact formats. Most of the former is placed on the blade surface by piezoelectric ceramics, ac...

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