A Computer Vision-Based On-Line Monitoring Method of Cable Distributed Stress

Abstract

The invention discloses an on-line monitoring method of inhaul cable distribution stress on the basis of computer vision. The on-line monitoring method comprises the following specific implementation steps: A: erecting two high-speed cameras, and debugging camera shooting parameters; B: carrying out the three-dimensional construction of a testing zone, system calibration and the initial setting of a system; C: carrying out three-dimensional target characteristic point extraction and three-dimensional space model deformation calculation; and D: carrying out automatic on-line monitoring and real-time storage of inhaul cable testing zone stress.

Description

technical field [0001] The invention relates to on-line monitoring of the stress state of a pull-down cable under various loads by using a visual sensor and a digital image processing method. Background technique [0002] Steel cables are important load-bearing components of long-span bridges (such as cable-stayed bridges, suspension bridges and arch bridges, etc.), and their stress status directly affects the applicability and safety of the entire bridge structure. During the tension construction and bridge operation of the cable structure, due to the influence of material properties, construction conditions and environmental conditions, stress loss or excessive stress will occur, which will cause the prestress level of the cable to exceed the preset safety range. The safety of the bridge structure is threatened. The structural damage of the bridge caused by the abnormal stress state of the cables is easy to cause safety accidents, which is not allowed in the bridge constr...

AI Technical Summary

Problems solved by technology

However, this monitoring method is currently in the research stage, and its susceptibility to electromagnetic interference and complex nonlinear problems between guided waves, stress, and material geometry directly affect the popularization and application of this method.

[0011] Summarizing the above several cable stress monitoring methods, the traditional cable stress monitoring method can only monitor the cable force at the anchorage end but cannot realize distributed measurement of the cable (strain pressure ring), or cannot Realize on-line monitoring (frequency method), or have very high requirements on processing technology (fiber grating sensor), or are very sensitive to temperature effects (magnetic flux sensor), or because the nonlinear conversion relationship of physical quantities is very complicated (ultrasonic guided wave), or because Most monitoring methods are susceptible to electromagnetic interference, which can introduce large errors in measurements

In addition, the traditional monitoring method requires the upper bridge to carry out wiring and other processes, the measurement process is relatively complicated, and the sensor is not easy to replace

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