基于线结构光的盾尾间隙测量方法研究

Research on the shield tail clearance measurement method based on line structured light

针对现有盾构施工中盾尾间隙难以实时精确测量的问题,本文提出了一种基于线结构光的盾尾间隙自动测量方法。该方法首先利用线激光器在管片和盾壳之间投射出一道窄线型指示激光并通过工业相机实时采集线激光器投射在盾壳和管片之间的线激光图像,然后通过图像处理对图像目标特征进行识别并根据单目视觉成像原理和线结构光坐标测量算法提取盾尾间隙端点坐标,进而实现盾尾间隙值的精确解算。实验结果表明,本文所提出方法的重复性测量精度优于0.3 mm,绝对测量精度优于1.7 mm。该方法可以实现相机纵深方向0.2~1.9 m范围内盾尾间隙的实时精确测量,满足城市地铁隧道施工应用需求。

The shield tail clearance is difficult to be accurately measured in real time during the on-site construction.To address this issue,this article proposes an automatic shield tail clearance measurement method based on the linear structured light.Firstly,a linear laser is used to project a narrow line-shaped indicator laser between the shield shell and the tube.The line laser image projected by the line laser between the shield shell and the tube is collected in real time through an industrial camera.Then,the target features are recognized by image processing and the end coordinates of shield tail clearance are extracted according to monocular vision imaging principle and line structured light coordinate measurement algorithm.In this way,the accurate solution of shield tail clearance value is realized.Experimental results show that the repeatability measurement accuracy of the proposed method is better than 0.3 mm,and the absolute measurement accuracy is better than 1.7 mm.This method can realize the real-time accurate measurement of the shield tail clearance within the range of 0.2~1.9 m in the depth direction of the camera,which can meet the application requirements of the urban subway tunnel construction.