Imaging method and device for realizing automatic track board crack detection

Abstract

The invention discloses an imaging method and device for realizing automatic track board crack detection. The imaging method comprises the steps: using a camera for detecting track board crack surfacedefects; carrying out exciting by using an ultrasonic transmitting and receiving device, and transmitting an ultrasonic signal in the frequency of 1-5MHz to the interior of a track board through an ultrasonic linear array probe; acquiring a diffusion field signal in the track board in a self-transmitting and self-receiving mode by the ultrasonic linear array probe and transmitting the diffusion field signal to a computer; passively extracting a Green function from the received signal by the computer through MATLAB software; performing cross-correlation on the diffusion field signal, reconstructing a Green function between array elements, obtaining non-delayed response between the array elements, recovering early defect information submerged by noise, and then performing track plate crackimaging according to a frequency domain synthetic aperture focusing imaging algorithm. According to the invention, the defects on the crack surface and inside the crack of the ballastless track boardcan be efficiently detected in real time in a nondestructive manner.

Description

technical field [0001] The invention relates to an imaging method and device for realizing automatic detection of track plate cracks, belonging to the technical field of track defect detection. Background technique [0002] High-speed railway is of great significance for shortening the distance between cities and promoting coordinated regional development, and is an indispensable part of modern transportation methods. With the rapid development of high-speed railways, ballastless track, as a main track structure, is composed of ballastless track slab, CA mortar layer, support layer and foundation bed, and its application range is getting wider and wider. However, in recent years, more and more diseases have appeared in the offline structure of the high-speed rail, including the off-line structural clearance, through cracks, and voids in the CA mortar layer. The main reason is that the ballastless track will be squeezed and impacted during the high-speed and heavy-load opera...

AI Technical Summary

Problems solved by technology

The main reason is that the ballastless track will be squeezed and impacted during the high-speed and heavy-load operation of the train, which may cause looseness, cracks or cavities inside, and various damage layers or honeycomb layers on the outside. On the other hand, there may be defects in the ballastless track itself due to problems in the construction process and construction experience in the pre-production; in addition, natural disasters such as rain and snow erosion and environmental temperature changes will also lead to defect

The existence of defects will seriously affect the bearing capacity and durability of the ballastless track, which will cause the structure of the ballastless track to fail, and the stability and smoothness of the ballastless track and the offline structure of the high-speed railway cannot be guaranteed. It is precisely an important prerequisite to ensure the fast and safe operation of high-speed rail, and will directly affect the normal operation of the train and the personal safety of passengers

[0003] However, at present, the detection of ballastless track defects in my country mainly relies on manual static detection technology. Since the effective skylight time for rail transit to be used for line maintenance is only 2-3 hours, and the high-speed railway line is very long, if the existing Some detection methods not only consume a lot of manpower and material resources, but also are very inefficient, and the cost of detection and maintenance is very high, so that they cannot meet the needs of track safety early warning

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