一种基于视觉引导的激光经纬仪自动测量系统

Laser automatic theodolite measurement system based on vision guidance

为了实现对目标自动识别和自动测量,建立了一种基于视觉引导的新型激光经纬仪自动测量系统。利用两台TM5100a激光经纬仪作为精密角度传感器,采用二维精密转台带动相机代替人眼对被测区域进行扫描,引导经纬仪望远镜指向相机视场,进而对视场中的目标点进行识别和瞄准测量。对系统的自动视觉引导方法进行了研究。首先通过对精密转台和双经纬仪系统的标定实时引导经纬仪激光点进入相机视场,分别利用质心法和椭圆拟合法对视场内的激光点和目标点进行特征提取和定位;建立系统判别跟踪模型,实现对视场内各目标点的逐一跟踪瞄准;最后利用系统定向结果和双经纬仪系统瞄准目标的方位角度值,解算出目标三维坐标。实验结果表明:该方法对目标点的测量误差为亚mm级,维持在0.3 mm以内。

To realize object automatic recognition and measurement,a new laser theodolite automatic measurement system based on vision guidance is established.In this system,two TM5100a theodolites were used as precision angle sensors with a camera mounted on a 2D rotation stage instead of the human eyes to scan the measurement field.The telescopes of the theodolites were guided to point to the view field of the camera,and then the target points in the view field were recognized,collimated and measured.This paper mainly described the guidance methodology model of the system.First,the collimation axis of the theodolite is guided into the view field of the camera according to the calibration of the relationship between the precise rotation stage and the double-theodolite system.Then,the laser point and the target points were recognized and oriented with the centroid method and ellipse fitting method,respectively after the laser points from the theodolites were guided to be in the view field of the camera.Then an object discriminating and tracking model was established.Finally,the coordinates of the target points were attained by the orientation parameters and the collimation azimuth angles of the theodolites.The experimental results show that the measuring precision of the system is within 0.3 mm at present,which demonstrates that the system can satisfy certain large-scale measurement demands to some extent and can accelerate the automation and high-efficiency process of the large-scale measurement system.