车载移动测量系统检校技术及其精度评定方法

发布时间：2018-07-11 15:30

本文选题：车载移动测量系统 + 检校　；参考：《武汉大学》2016年博士论文

【摘要】：近十几年来,随着经济社会发展和测绘科学技术进步,测绘地理信息行业发生了翻天覆地的变化,测绘地理信息数据获取方式也发生了巨大改变。快速、经济、高效的测绘地理信息数据获取方式的出现,如导航定位服务、卫星遥感、无人机航测、车载激光测量等技术应用,彻底改变了测绘地理信息传统的作业模式和工作流程。车载移动测量系统作为一种高新的测绘地理信息仪器装备,近年来随着数字城市、智慧城市、地理国情监测等相关工作的不断推进,以及该领域学者们的不断努力,其在测绘地理信息生产中的作用也日益突出。车载移动测量系统是一种兼有定位、测距、测角和摄影功能的系统,集成了GNSS单元、惯性测量单元(IMU)、激光扫描仪、数字相机以及自动控制等技术,以实现对目标区域的空间数据、属性数据以及实景影像等多种信息的快速采集。在实际工程应用中,车载移动测量系统的综合精度始终是最重要的因素。为了确保系统的综合精度,系统作业前需要经过严格的检校,系统检校是数据处理前必须首要解决的问题,是难点,也是关键点,否则,精度无从谈起。本文在推导系统定位模型基础上,总结了系统误差来源,分析了各部分误差对系统精度的影响,提出了单机检校和组合检校方法,并提出系统综合精度的评定指标和评定方法。本文的主要工作和创新点概括如下：1.详细介绍了车载移动测量系统的组成部分、各部分的工作原理和理论基础,阐述了它们在系统中的功能和作用,详细推导了系统的定位模型,分析了系统硬件集成的关键技术。2.分析车载移动测量系统与传感器相关、与系统硬件集成相关的误差来源、性质与处理方法；推导了各项误差模型,定量分析了各项误差对系统综合精度的影响；并通过定位模型从理论上估计系统精度,给系统集成过程中传感器的选择提供参考。3.提出了车载移动测量系统单机检校的概念,利用精度为1×10-11s的铷钟和5×10-11s时间计数器对GNSS接收机的1PPS授时精度进行评定；利用短基线和零基线方法通过GAMIT软件动态解算进行GNSS PPK精度评定；利用GT580型双轴转台和POSLV610进行IMU姿态角精度评定,两种方法结合可以更加准确地评定IMU姿态角精度；利用精度为0.3”的多齿分度台对激光扫描仪进行测角精度评定,该方法精度高、稳定性好、可溯源；根据激光扫描仪的测距检校模型和测角检校模型,通过最小二乘解算相应的检校参数；重点研究了测角法对数字相机进行单机检校,通过测定平行光线的入射角度和其对应像片上的像点坐标,根据镜头畸变平方和最小原则解算出内方位元素和畸变参数,改正后的剩余畸变为0.2个像素,该方法是在实验室内进行,检校条件可控,检校过程标准规范。4.提出了车载移动测量系统组合检校的概念,重点研究了利用手动检校方法、基于控制点的检校方法和基于特征面的检校方法三种方法进行激光扫描仪和IMU的组合检校,基于控制点的检校方法精度最高,可以达到0.001。,手动检校灵活性好、但精度较低；通过点云坐标反算像点坐标,并将像点坐标的色彩信息赋给点云坐标完成激光扫描仪和数字相机的组合检校,点云和影像的套合精度为1-2个像素。5.通过建立永久性的检校场,借助自制的特殊标志和反射片作为特征点,便于点云特征提取,提出车载移动测量系统综合精度评定的指标,利用传统方法获取这些特征点的高精度三维坐标和特征线的长度值作为基准值,通过与系统解算出来的特征点和特征线进行比较,从而完成系统的综合精度评定。并且评价了实际工程应用中系统的精度,研究表明,经过检校后的某车载移动测量系统,其平面精度可以达到0.028m,高程精度为0.019m,从而验证了本文提出的单机检校和组合检校方法的正确性。
[Abstract]:Over the past ten years, with the development of economy and society and the progress of Surveying and Mapping Science and technology, the geographic information industry has undergone tremendous changes, and the methods of obtaining geographic information data have also changed greatly. Rapid, economic and efficient mapping of geographic information data, such as navigation and positioning services, satellite remote sensing, unmanned aerial vehicles (UAV) The application of aerial survey and vehicle laser measurement has completely changed the working mode and work flow of Surveying and mapping geographic information. As a kind of high and new surveying and mapping geographic information instrument, the vehicle mobile measurement system has been advancing with the digital city, the intelligent city, the geographical condition monitoring and so on, as well as the scholars in this field. With the continuous efforts, the role of the vehicle in surveying and mapping geographic information production is becoming increasingly prominent. The vehicle mobile measurement system is a system with the functions of positioning, ranging, angle measurement and photography. It integrates the GNSS unit, the inertial measurement unit (IMU), the laser scanner, the digital camera and the automatic control to realize the number of space in the target area. In the practical engineering application, the comprehensive accuracy of the vehicle mobile measurement system is always the most important factor. In order to ensure the comprehensive accuracy of the system, the system needs to be strictly calibrated before the system operation, and the system verification is the first problem to be solved before the data processing, and it is difficult to solve the problem. The point is also the key point, otherwise, the accuracy of the system can not be discussed. On the basis of the derivation of the system positioning model, this paper summarizes the source of the system error, analyzes the influence of the error of each part on the system accuracy, puts forward the method of single machine calibration and combination verification, and puts forward the evaluation index and evaluation method of the system comprehensive accuracy. The main work and innovation of this paper are the main work and the innovation of the system. The following points are summarized as follows: 1. the components of the vehicle mobile measurement system, the working principle and the theoretical basis of each part are introduced in detail. The functions and functions of the system are expounded, the positioning model of the system is derived in detail, and the key technology of the system hardware integration,.2., is analyzed and the correlation between the vehicle mobile measurement system and the sensor system is analyzed. The error sources, properties and processing methods related to the integrated hardware integration, the error models are derived, and the effects of various errors on the integrated precision of the system are analyzed. The system accuracy is estimated from the location model in theory, and a reference.3. for the selection of sensors in the system integration process is proposed. The concept of calibrating, using a 1 x 10-11s rubidium clock and a 5 x 10-11s time counter to evaluate the 1PPS timing accuracy of the GNSS receiver, and using the short baseline and zero baseline methods to evaluate the GNSS PPK accuracy through the dynamic calculation of the GAMIT software, and evaluate the attitude angle accuracy of the IMU with the GT580 dual axis turntable and POSLV610, and two methods. The IMU attitude angle accuracy can be evaluated more accurately; the angle measurement accuracy of the laser scanner is evaluated by the multi tooth indexing table with precision of 0.3. The method has high accuracy, good stability and traceability. According to the laser scanner's range detection model and the angle measurement calibration model, the corresponding calibration parameters are solved through least squares. The angle measurement method is used to calibrate a digital camera. By measuring the incident angle of the parallel light and the coordinates of the image point on the image, the inner elements and the distortion parameters are calculated according to the minimum principle of the square and minimum of the lens distortion. The residual distortion after correction is 0.2 pixels. The method is carried out in the laboratory and the calibration condition is controlled. .4., the Standard Specification for the verification process, puts forward the concept of the combination verification of the vehicle mobile measurement system, and focuses on the combination of three methods, which are the manual calibration method, the control point based calibration method and the feature surface calibration method. The calibration method based on the control point can reach the highest precision and can reach 0. 1, the manual calibration is very flexible, but the precision is low. Through the point cloud coordinates back calculating the image point coordinates, and assigning the color information of the point coordinates to the point cloud coordinates to complete the combination of the laser scanner and the digital camera, the coincidence precision of the point cloud and the image is 1-2 pixels.5. through the establishment of a permanent calibration field, with the help of the special logo and the self-made logo. As a feature point, the reflector is easy to extract the feature of the point cloud, and puts forward the index of the comprehensive accuracy evaluation of the vehicle mobile measurement system. The traditional method is used to obtain the high precision three-dimensional coordinates and the length values of the characteristic lines as the datum value, and to compare the characteristic points and the characteristic lines calculated by the system, so as to complete the system synthesis. The accuracy of the system is evaluated and the accuracy of the system is evaluated in the actual engineering application. The research shows that the plane accuracy of a vehicle mobile measurement system after the calibration can reach 0.028m and the elevation accuracy is 0.019m, thus verifying the correctness of the single machine calibration and the combined calibration method proposed in this paper.
【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P234

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