Machine vision tidal bore flow velocity measurement method based on unmanned aerial vehicle

Abstract

The invention discloses a machine vision tidal bore flow velocity measurement method based on an unmanned aerial vehicle. The method is implemented by the following six links in sequence: video image acquisition, graying and filtering processing, edge detection, puffing operation, tidal head line extraction and tidal bore velocity calculation. A traditional fixed detection method can only obtain hydrological data of limited point locations, and for the research of the overall form and the propagation mechanism of the eagre, the information amount is limited. The unmanned aerial vehicle has the advantages of maneuverability, flexibility, wide detection range and the like, and more comprehensive tidal bore flow velocity information can be acquired. According to the tidal line detection method constructed by the invention, the influence of water waves and waves on the river surface is effectively avoided, the tidal line in any form is identified, and accurate point location information is provided. The tidal bore flow velocity measurement method provided by the invention has the advantages of large measurement space scale, accurate tidal head line identification, high non-contact safety and the like, can meet better tidal bore flow velocity measurement requirements, and provides more comprehensive data support for research of tidal bore propagation rules.

Description

technical field [0001] The present invention relates to the field of smart water conservancy, in particular to a method for measuring inrush current velocity based on machine vision of an unmanned aerial vehicle. Background technique [0002] The Qiantang River is the largest river in Zhejiang Province. It originates in southern Anhui, flows through Anhui and Zhejiang provinces, and finally flows into the East China Sea through Hangzhou Bay. When the tidal wave enters Hangzhou Bay and propagates upstream, the tidal range continues to increase. Hangzhou Bay The plane shrinks sharply, the tidal range increases, and the sand ridge of the Qiantang River makes the water depth decrease rapidly, which strengthens the shallow water effect of the tidal wave and leads to the deformation of the tidal wave, especially at the front of the high tide wave, thus forming a high tide with a sudden rise in water level The front line of the wave is the tidal surge, which is a unique natural lan...

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Problems solved by technology

Ji Sufang and others proposed to use edge detection and Hough transform to extract the tide front line. This method is simple and fast, and can extract the tide front line with a simple background and a straight tide shape. The speed of each point is not exactly the same, resulting in the shape of the tide is not a straight line, but an irregular curve, so this method cannot accurately extract the tide line of any shape; Zeng Xu et al. The tide background model based on video recognition is constructed by establishing a mixed Gaussian model, and then the obtained background image is subtracted from the current video frame to obtain the foreground image of the Qiantang River tide. After smoothing and denoising processing, the tide is detected information, but when there are many water ripples or light waves on the water surface, the detection results will be mixed with these water ripples and light waves, which will affect the extraction of tide front lines. The method of tide front line detection proposed in this paper can not only extract The tidal line of any shape can also effectively avoid the influence of water ripples and light waves on the river surface, and accurately extract the tidal line

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