【作者】 张洋；

【导师】 郑英；

【作者基本信息】 华中科技大学 ， 控制工程， 2021， 硕士

【摘要】 激光垂准仪是一种能提供铅垂线的仪器,广泛应用于建筑施工、形变观测和设备安装等行业。目前国内激光垂准仪需要依靠观察水泡完成仪器整平,整平精度受人工判读影响,而在仪器轴系安装和校准时,需要人工观察十字丝和光斑中心位置来标定同轴度,标定误差较大。因此本文旨在研制一种能数字化整平过程的激光垂准仪及采用图像处理方法的同轴度标定系统。本文研究了一种能数字化显示水泡位置的整平方法,该方法利用电子式长水泡传感器测量仪器倾角,并通过相关电路模块满足仪器整平过程和长水泡两点式校准方法的需求,实现一种新型数字化激光垂准仪。进一步地,本文提出了激光垂准仪同轴度的图像标定方法,该方法在相机标定时,用图像差分法解决背景干扰的问题,采用Otsu算法对图像二值化处理,利用霍夫变换完成图像校正后识别坐标刻度得到坐标映射关系。在目标定位时,采用K-means聚类方法分割十字丝后利用霍夫变换定位十字丝中心,采用单通道法分割光斑区域后取其质心为光斑中心,并基于最小二乘法分别对中心点轨迹进行圆拟合,得到激光垂准仪同轴度误差。最后,利用RK3399嵌入式平台实现了同轴度图像标定系统的搭建。实验结果表明,本文研制的数字化激光垂准仪能提升长水泡显示分辨率,减小人工误差,显示分辨率达1.29’’。研制的同轴度图像标定系统能够准确标定激光垂准仪同轴度误差,标定精度达0.1’’。更多还原

【Abstract】 Laser plummet is a kind of instrument which can provide plumb line.It is widely used in construction,deformation observation,equipment installation and other industries.At present,the domestic laser plummet needs to be leveled by observing the bubble level,and the leveling accuracy is affected by the error of artificial observation.When the shaft of laser plummet is installed and calibrated,the coaxiality of the shaft is calibrated by observing the center of cross lines and laser spot,and the error of calibration is large.The purpose of this thesis is to develop a digital laser plummet which can digitize the leveling process and a calibration system of coaxiality based on image processing.This thesis proposes a leveling method which can display the position of the bubble digitally.This method uses electronic bubble level sensor to measure the inclination angle of the laser plummet,and uses the relevant circuit modules to meet the needs of leveling process of laser plummet and calibration method of the long bubble level by being rotated to two angles,and develops a new digital laser plummet.Furthermore,this thesis proposes a new calibration method for coaxiality of laser plummet based on image processing.When calibrate the camera,using image difference to solve the interference from background,and Otsu algorithm is used to binarize the image.After image correction,using Hough transform algorithm to recognize the scale and get mapping relation of two kinds of coordinate.When detect the target,K-means clustering method is used to segment the cross lines,Hough transform is used to locate the center of cross lines,using single channel method to segment the laser spot area,and the centroid of the area is taken as the spot center.Based on the least square method,the center point trajectory is caculated to obtain the coaxiality error of the laser plummet.Finally,the calibration system of coaxiality based on image processing is built based on RK3399 embedded platform.Experimental results show that the digital laser plummet developed in this thesis can improve the resolution of the long bubble level,and reduce the error of artificial observation,the resolution is up to 1.29’’.The new calibration system of coaxiality based on image processing can accurately calibrate the coaxiality error of the laser plummet,and the calibration accuracy is up to 0.1’’.更多还原