Research On Shield Tail Clearance Measurement System Of Shield Machine Based On Binocular Vision

Nowadays,tunnel engineering of subway can be seen everywhere,especially in first-tier cities.Shield machine has been widely used due to its many advantages such as high degree of mechanization,fast excavation speed and high safety factor.In shield construction,many parameters are very important.It may affect the entire shield construction project if one of the parameters is abnormal.The shield tail clearance is one of the parameters.It needs to be measured every time the shield machine advances a small distance.The gap of shield tail is the gap between the outer ring of the segment and the shell of the shield machine.If the parameter is too small,the segment is likely to be crushed,which will lead to a series of safety problems due to damage to the segment,even it will lead to the occurrence of major engineering accidents,therefore the measurement of shield tail clearance occupies a very important position in shield construction.At present,manual measurement of the gap of shield tail is the main method in China,but manual measurement will cause a series of safety and accuracy problems due to environmental factors and own factors,such as safety problems caused by manual climbing and accuracy problems caused by the arbitrariness of manual measurement.Therefore,this article develops a measurement system of gap of the shield tail based on actual needs,and uses Qt as the development platform,and uses OpenCV as the implementation library of vision algorithm.By the interface,the camera is remotely controlled to collect the image of gap of shield tail and perform image processing,and then the shield tail is obtained according to the vision algorithm,at the same time the gap value is displayed on the interface,finally Microsoft SQL Server is used to realize the data storage,query and export functions.The main research content of this paper is the research of the algorithm of binocular vision of the measurement system,the software development and the structural design of the mechanical protection box.The details are as follows:(1)Introduce the technology of shield construction and the technology of automatic measurement of the gap of shield tail.(2)Carry out structural design of the protective box according to the on-site environment.(3)According to the on-site environment and design requirements,selecting the hardware required for the measurement system,and using 3D printing technology to build a gap model of shield tail in the laboratory.(4)Assembling the relevant hardware and performing camera calibration,then collecting images on the experimental platform,and performing image processing.Finally obtaining the gap value of shield tail according to the algorithm of binocular vision.(5)After completing the interface design,repeating the shield tail gap measurement experiment to continuously improve the accuracy of the measurement system.