Deformation monitoring method based on vision measurement

Abstract

The invention provides a deformation monitoring method based on vision measurement, and belongs to the technical field of deformation monitoring. The deformation monitoring method comprises the following steps that the mark plate of deformation monitoring is designed, wherein the mark plate is formed by a white baseplate and four black circular sheets which are arranged on the baseplate, the boundaries of the circular sheets cannot be tangent, intersected or overlapped, the connecting line of the center of the circle of the two circular sheets is a first connecting line, the connecting line of the center of the circle of the rest two circular sheets is a second connecting line, and the first connecting line and the second connecting line are perpendicular and intersected; characteristic contour models of different resolutions are established; subsequent images of different time points are acquired, and the elliptic center coordinates on the subsequent images, i.e. the coordinates of mark points, are accurately extracted; and the displacement of the mark points in the subsequent images is calculated, and the calculated displacement is corrected so that the actual displacement of the mark points is obtained. The deformation monitoring method based on vision measurement is easy to operate, high in degree of automation, low in cost, high in precision, simple in data processing and high in efficiency.

Description

technical field [0001] The present invention relates to the technical field of deformation monitoring, in particular to a deformation monitoring method based on vision measurement. Background technique [0002] Deformation monitoring is to use professional measuring instruments and supporting instruments to continuously observe the shape, size and position changes of deformed objects, which requires very high measurement accuracy and reliability. At present, the commonly used geodetic deformation monitoring technologies mainly include total station, GNSS, leveling, etc. These technologies have the advantages of high precision, but the cost is relatively high; deformation monitoring instruments such as displacement sensors need to be installed on the monitoring structure, and the construction is difficult larger. [0003] Vision measurement is a non-contact measurement method, which has the advantages of simplicity and low cost. With the development of digital camera techno...

AI Technical Summary

Problems solved by technology

At present, there are two main ways to use visual measurement for deformation monitoring: one is the 3D reconstruction technology for deformable objects, which has the advantages of simplicity and flexibility, and can reflect the overall shape of the target and the 3D deformation trend. One of the main methods, but when the surface texture of the morphing target is simple, the shooting distance is long, and the shooting angle is too small, the 3D reconstruction accuracy will be affected by factors such as insufficient number of feature points and excessive ray intersection error; when the morphing target has a large range or no When the reference point is stabilized, it is difficult for 3D reconstruction to provide reasonable and reliable deformation monitoring results

The other is the visual tracking technology for monitoring targets, which is often used in two-dimensional displacement monitoring. According to different observation conditions and data processing technologies, it can be divided into two types: indoor and outdoor measurement; indoor measurement is affected by light, air humidity, etc. Therefore, more attention should be paid to the fine processing of images, but the monitoring distance is generally short and cannot be applied to large-scale and long-distance deformation monitoring, so it is often used in industrial measurement; outdoor measurement is mainly for Deformable bodies such as dams, bridges, and buildings need to use equipment such as telephoto lenses. At present, outdoor measurement research mainly focuses on high-dynamic measurement, such as using laptops, cameras, telephoto lenses and other equipment to perform real-time two-dimensional displacement of bridges. Deformation monitoring; using cameras to monitor the inclination of high-rise buildings in real time has achieved good experimental results, but the monitoring distance of these applications does not exceed 20m, and the monitoring time is short, ignoring the long-term monitoring environment and The impact of cameras and other equipment on the measurement accuracy; at the same time, the identification of monitoring points is completely based on the gray scale and geometric information of marker points, and the imaging range of marker points is too small to increase the recognition error rate, which also indirectly limits the monitoring distance and monitoring range.

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