Online roadbed compactness detection method based on machine vision

Abstract

The invention discloses an online roadbed compactness detection method based on machine vision and belongs to the field of roadbed compactness detection method. The online roadbed compactness detection method comprises the following steps of: (1) establishing a vision measurement system: a measurement system for one compactness sampling point consists of a CCD ( Charge Coupled Device ) camera, a sampling mark feature point and a mark pile; (2) image processing: the CCD camera collects the image of a compaction site and obtains three crossed shapes of the mark pile through fitting, and the image coordinate of the center of sampling mark feature point and the long axis and short axis parameters of an ellipse are extracted; (3) settlement calculation: the vertical distance between the center of the sampling mark feature point and a selected reference point of the mark pile is obtained through calculation, and the settlement of the compaction operation is obtained; and (4) roadbed compactness calculation: the settlement is substituted into the settlement-compactness mathematical model. The online roadbed compactness detection method takes images as the carrier for detection and information transfer; and as image data is stored in a computer, construction documents can be well saved, and the quality and efficiency of compaction operation are improved.

Description

technical field [0001] The invention relates to a method for detecting the degree of compaction of a roadbed, in particular to an on-line detection method for the degree of compaction of a roadbed based on machine vision. Background technique [0002] The degree of compaction refers to the ratio of the dry density of soil or other road construction materials after compaction to the standard maximum dry density, expressed as a percentage. The degree of compaction is one of the key indicators for the quality inspection of subgrade and pavement construction. It represents the density status after on-site compaction. The higher the degree of compaction, the greater the density, and the better the overall performance of the material. The degree of compaction test usually adopts the random sampling method, that is, samples are taken from the rolled materials, and the density and static elastic modulus are measured to reflect the compaction quality. The random sampling methods com...

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Problems solved by technology

[0031] (1) This measurement method needs to destroy the soil layer structure, too much sampling will affect the performance of the subgrade, and the data reliability is low with fewer sampling points;

[0032] (2) The compaction state cannot be measured and evaluated during the compaction process, and can only be detected after the compaction is completed;

[0034] (4) The labor intensity of the workers is relatively high;

[0035] (5) The detection speed is relatively slow, and online detection cannot be realized

[0044] Disadvantages of prior art 2: At present, the positive correlation between acceleration amplitude and compaction degree is quite controversial, and the applicant organized and implemented many vibration compaction tests during the master's degree, and found that as the compaction proceeds, the compaction The solidity is gradually increasing, but the acceleration signal has an abnormal performance, which may be caused by different parameters such as soil gradation and water content.

[0052] Shortcomings of the prior art 3: First, the applicability of the compaction gauge in some new compaction methods has yet to be verified, such as the chaotic compaction technology proposed by Long Yunjia of China Agricultural University, the acceleration signal of the vibrating wheel is in a wide range There are distributions inside, and the harmonic components are not very obvious

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