车载移动测量系统集成关键技术研究

发布时间：2018-08-17 13:49

【摘要】：城市三维空间信息的快速获取是当今测绘研究领域的热点之一,随着社会发展与进步,现代城市及基础建设发展日新月异,要求高效率(快)、大面积(广)、高精度(精)和全面生动(真)地获取城市空间信息数据,传统的以全站仪为主要手段的城市测量劳动强度大、作业效率低,难以满足城市空间信息获取快、广、精、真的需求；而车载移动测量系统的出现为高效率、大面积、高精度的获取城市空间信息提供了可能,车载移动测量系统是目前最为引人注目的城市空间三维信息获取技术之一。目前,3D Laser Mapping、Applanix、 Riegl等国外公司已实现车载移动测量系统的商业化,但其所售车载移动测量系统价格昂贵,严重阻碍了车载移动测量系统在国内的应用。因此,研究车载移动测量系统的集成具有重要意义。本论文对车载移动测量系统集成中的各种核心技术进行了广泛而深入的研究,包括车载多传感器时空同步技术、DGPS/INS组合定位定姿技术、车载立体影像量测技术、车载激光扫描技术、车载多传感器的联合标定等。(一)车载多传感器时空同步技术。时空同步技术是多传感器集成的重要技术,精确的时空同步是车载移动测量系统实现高精度三维空间信息采集的前提。本文分析了GPS、惯导、激光扫描仪以及相机等的时空特性,并采用高稳晶振,设计并实现了一种同步控制器；该同步控制器在作业过程中引入GPS时间系统并在GPS信号中断期间维持该时间系统,能够长时间的实现多传感器的高精度时间同步。(二)DGPS/INS组合定位定姿技术在车载移动测量系统中的应用。传统摄影测量中,采用布设控制点进行空三加密的方法得到影像的外方位元素；车载移动测量系统中使用组合定位定姿技术,直接为影像提供外方位元素,称为直接地理定位(Direct Georeferencing)技术。本文采用直接地理定位方法,为车载影像与激光扫描数据提供直接地理定位,建立车载影像立体量测模型与车载激光扫描直接地理定位模型。(三)车载立体影像量测技术。数字相机是车载移动测量系统中的常用传感器,在车载移动测量系统中一般按照特殊的安装方式集成多对数码相机,每对数码相机采集的影像可构成立体像对进行立体量测。车载立体影像量测技术来源于摄影测量,但是又与传统的摄影测量有所区别,本文建立了直接地理定位下的车载立体影像的量测模型并开发了相应的车载立体影像量测软件。(四)车载激光扫描测量技术。地面激光扫描技术(固定式地面激光扫描)能够高效率、高精度的获取局部区域的三维空间信息,将激光扫描技术应用于车载移动测量系统中,能够解决大范围大区域三维空间信息的快速高效获取。本文将SICK LMS系列激光、Riegl系列激光以及Faro focus 3D激光扫描仪用于车载移动测量系统中,建立了车载激光扫描的绝对定位模型,将“二维”点云重建为三维激光点云,实现大范围三维空间信息的快速高效获取。(五)车载多传感器集成系统的整体标定。未经整体标定的车载移动测量系统存在多种未知的系统参数,包括相机的主点位置、主距、镜头畸变、相机之间的相对空间关系、相机与激光扫描仪之间的相对空间关系、相机与惯导之间的空间关系以及激光扫描仪与惯导之间的空间关系等。本文在对车载多传感器集成系统中各系统参数深入分析与建模的基础上,利用三维标定场与二维标定板,完成了车载移动测量系统中各未知系统参数的解算,使本文研制的车载移动测量系统的定位精度达到厘米级水平。在研究车载移动测量系统集成各个核心技术的基础上,本文完成了三种完整的移动测量系统的集成,论文研究的面向城市测量的移动测量系统和面向空间信息采集与发布的移动测量系统的软、硬件及应用成果分别通过宁波市规划局和国家测绘地理信息局的科技成果鉴定；通过实际工程中的应用与验证也证明,本论文研究成果达到了预期目标。
[Abstract]:Rapid acquisition of urban three-dimensional spatial information is one of the hotspots in the field of Surveying and mapping. With the development of society and the rapid development of modern cities and infrastructure, it is required to obtain urban spatial information data with high efficiency (fast), large area (wide), high precision (precise) and full vividness (true). Traditional total station instrument is the main means. Urban surveying has high labor intensity and low efficiency, which is difficult to meet the needs of fast, wide, precise and real urban spatial information acquisition. The emergence of vehicle-borne mobile surveying system provides the possibility of acquiring urban spatial information with high efficiency, large area and high precision. At present, 3D Laser Mapping, Applanix, Riegl and other foreign companies have realized the commercialization of on-board mobile measurement system, but the high price of on-board mobile measurement system has seriously hindered the application of on-board mobile measurement system in China. Therefore, it is of great significance to study the integration of on-board mobile measurement system. Various key technologies in the integration of vehicle-borne mobile measurement system are studied extensively and deeply, including vehicle-borne multi-sensor space-time synchronization technology, DGPS/INS integrated positioning and attitude determination technology, vehicle-borne stereo image measurement technology, vehicle-borne laser scanning technology, vehicle-borne multi-sensor joint calibration technology, etc. (1) vehicle-borne multi-sensor space-time synchronization technology. Space-time synchronization technology is an important technology of multi-sensor integration. Accurate space-time synchronization is the premise of high-precision three-dimensional space information acquisition for vehicle-borne mobile measurement system. GPS time system is introduced into the step controller and maintained during the interruption of GPS signal, which can realize high precision time synchronization of multi-sensors for a long time. (2) Application of GPS/INS integrated positioning and attitude determination technology in vehicle-borne mobile measurement system. In this paper, the direct geo-location method is used to provide direct geo-location for vehicle images and laser scanning data, and the vehicle-borne mobile measurement system uses combined positioning and attitude determination technology to directly provide external orientation elements for the image, which is called direct geo-location technology. 3. Vehicle-borne stereo image measurement technology. Digital camera is a common sensor in vehicle-borne mobile measurement system. In vehicle-borne mobile measurement system, many pairs of digital cameras are integrated according to special installation method, and each pair of images collected by digital cameras can be constructed. Vehicle-borne stereo image measurement technology originates from photogrammetry, but it is different from traditional photogrammetry. This paper establishes the measurement model of vehicle-borne stereo image under direct geographic location and develops the corresponding vehicle-borne stereo image measurement software. (4) Vehicle-borne laser scanning measurement technology. Laser scanning technology (fixed terrestrial laser scanning) can obtain high-efficiency and high-precision three-dimensional spatial information of local areas. The application of laser scanning technology in vehicle-borne mobile measurement system can solve the problem of fast and efficient acquisition of large-scale and large-scale three-dimensional spatial information. In this paper, SICK LMS series laser, Riegl series laser and Far series laser are introduced. O-focus 3D laser scanner is used in vehicle-borne mobile measurement system. The absolute positioning model of vehicle-borne laser scanning is established. The "two-dimensional" point cloud is reconstructed into three-dimensional laser point cloud, and the large-scale three-dimensional spatial information can be obtained quickly and efficiently. (5) The overall calibration of vehicle-borne multi-sensor integrated system. There are many unknown parameters in the measurement system, including the main point position of the camera, the main distance, lens distortion, the relative spatial relationship between the cameras, the relative spatial relationship between the camera and the laser scanner, the spatial relationship between the camera and the inertial navigation, and the spatial relationship between the laser scanner and the inertial navigation. On the basis of in-depth analysis and modeling of system parameters in the integrated system, the unknown system parameters in the vehicle-borne mobile measurement system are solved by using three-dimensional calibration field and two-dimensional calibration board. The positioning accuracy of the vehicle-borne mobile measurement system developed in this paper reaches centimeter level. On the basis of the center technology, this paper completes the integration of three complete mobile measurement systems. The software, hardware and application results of the mobile measurement system for Urban Surveying and the mobile measurement system for spatial information collection and publication are tested by Ningbo Municipal Planning Bureau and the State Bureau of Surveying and Mapping Geographic Information respectively. Through the application and verification of the actual project, it is also proved that the research achievement of this paper achieves the expected goal.
【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：P235

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