基于里程计的车载LiDAR组合导航研究

发布时间：2018-10-05 08:48

【摘要】：车载激光雷达(LiDAR, Light Detection And Ranging)移动测量系统是一种主动式的测量系统,它是集激光测距技术、计算机技术、GNSS定位技术、惯性导航技术(INS)、CCD技术等高新技术于一体的现代测量装备,具有地面控制少、自动化程度高、作业周期短等特点。由于车载LiDAR在三维数据获取、道路资产普查、数字城市三维建模等方面具有巨大优势,并且机动性强、成本费用低,已经在各个领域得到广泛的应用。车载LiDAR的作业精度受多方面因素的影响,除了激光测距测角误差、IMU测姿误差、各种传感器的偏移矢量等系统误差外,影响最大的是由复杂的城市环境所造成的GPS信号失锁、多路径效应等引起的组合导航精度下降。基于GPS失锁情况下的组合导航精度下降问题,文章针对里程计在提高车载LiDAR组合导航精度的应用进行了研究,具体内容如下： 1.基于霍尔元件的里程计构建技术研究。里程计作为车载LiDAR组合导航中重要的传感器,主要负责记录车辆的里程信息,通过将霍尔接近开关安装在车体上作为静子,强磁体安装在轮毂上作为转子,完成了对车载里程计构建,并通过实验对霍尔里程计的脉冲当量及相对于IMU的偏移矢量进行标定。 2.里程计在组合导航中的应用研究。对里程计在系统平面精度、影像姿态等方面的影响进行实验分析,得出结论：在一定程度上高分辨率的里程计要优于低分辨率的里程计；GPS失锁2分钟时,使用里程计可将车载LiDAR的平面偏差控制在0.6m以内；同时里程计对影像姿态有一定的修正作用。 3.提高组合导航精度方法研究在实际作业过程中,还需要一些特殊手段来提高车载LiDAR的组合导航精度,实验证明使用里程计进行零速修正、使用航迹点控制轨迹漂移等能有效控制在GPS失锁时的组合导航精度,对数据采集路线进行规划也在一定程度上能够保证数据精度,提高作业效率。
[Abstract]:The (LiDAR, Light Detection And Ranging) mobile measurement system of vehicle lidar is a kind of active measurement system. It is a modern measuring equipment which integrates high and new technologies such as laser ranging technology, computer technology, (INS) technology, inertial navigation technology and so on. Has the ground control small, the automation degree is high, the work cycle is short and so on characteristic. Vehicle LiDAR has been widely used in many fields because of its great advantages in 3D data acquisition, road asset survey, 3D modeling of digital city, and its mobility and low cost. The operational accuracy of LiDAR is affected by many factors. Besides the errors of laser ranging and attitude measurement, and the offset vector of various sensors, the most important influence is the loss of lock of GPS signal caused by complex urban environment. The accuracy of integrated navigation is reduced due to multipath effect. Based on the decline of integrated navigation accuracy in the case of GPS lost lock, this paper studies the application of mileage meter in improving the precision of vehicle LiDAR integrated navigation. The specific contents are as follows: 1. Research on building technology of odometer based on Hall element. As an important sensor in the vehicle LiDAR integrated navigation, the mileometer is mainly responsible for recording the mileage information of the vehicle. By installing the Hall proximity switch on the car body as the stator, the strong magnet is installed on the hub as the rotor. The vehicle odometer is constructed and the pulse equivalent of Hall odometer and the offset vector relative to IMU are calibrated by experiments. 2. Research on the Application of mileage Meter in Integrated Navigation. The effects of mileometer on system plane precision and image attitude are analyzed experimentally. It is concluded that the high resolution odometer is better than the low resolution mileometer when GPS loses lock for 2 minutes to a certain extent. The plane deviation of the vehicle LiDAR can be controlled within 0.6 m by using the mileometer and the image attitude can be corrected by the mileage meter. 3. Research on the method of improving the accuracy of Integrated Navigation in practice, some special methods are needed to improve the accuracy of integrated navigation of vehicle LiDAR. It is proved by experiments that the mileage meter is used for zero speed correction. Using track points to control trajectory drift can effectively control the integrated navigation accuracy when GPS is out of lock. Planning the data acquisition route to a certain extent can also ensure the data accuracy and improve the operation efficiency.
【学位授予单位】：首都师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P225

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