Regulation of Navigation Channel on Mouth Bar of Guanhe Estuary     

Li Guochen Associate Professor  Hohai University  Nanjing 《中国海洋工程》1994,(3)

-Based on the feasibility study of developing the navigation resources of the Guanhe River and the model test results of the mouth bar regulation, this paper presents some basic principles for the regulation of the channel on the mouth bar, for instance, the direction of navigation channel should be identical with that of the ebb tide current and the main waves, and perpendicular to the bathymetric contours. The principles for regulating mouth bars are also discussed in this paper.  相似文献   

Robust and adaptive path following for underactuated autonomous underwater vehicles   总被引：1，自引：0，他引：1  

K. D. Do  J. Pan  Z. P. Jiang 《Ocean Engineering》2004,31(16):1967-1997

This paper proposes a nonlinear robust adaptive control strategy to force a six degrees of freedom underactuated underwater vehicle with only four actuators to follow a predefined path at a desired speed despite of the presence of environmental disturbances and vehicle’s unknown physical parameters. The proposed controller is designed using Lyapunov’s direct method, the popular backstepping and parameter projection techniques. The closed loop path following errors can be made arbitrarily small. Interestingly, it is shown that our developed control strategy is easily extendible to situations of practical importance such as parking and point-to-point navigation. Numerical simulations are provided to illustrate the effectiveness of the proposed methodology.  相似文献   

Investigation on the Deposition in an Excavated Trough at the East Shore of Jiaozhou Bay, China     

Zhang Jinshan Yu Guohua Research Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing Research Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1995,(3)

- Based on field investigations, this paper analyzes three types of harbour basinns and navigation channel excavated on seabed in Jiaozhou Bay, get a general rule of deposition for excavated trough, it found that pollution is one of crucial factors resulting in the deposition of the excavated trough in the east shore of Jiaozhou Bay. With these results, it predicted the annual deposition thickness for the excavated trough and disclosed the fact that it can't be deposited deadly during one storm. At the same time, with two-dimensional numerical model, it studied the effects of the excavated trough and the reclamation near shore on tidal cureent and said that the excavated trough can decrease the current velocity passing through the trough about 10- 15%, but only limited inside and near the trough and there are no effect on other regions; reclamation can cut off the pollution sources and no obvious effect on the currents of the Jiaozhou Bay. Connecting the deep trough and Cangkou tidal channel with a new  相似文献   

北斗三星无源导航定位技术研究     

方兆宝  夏哲仁  赵培海  周琼华  田震华  许泽明 《海洋测绘》2007,27(2):15-17

简述北斗三星无源导航定位的原理及定位误差源。探讨用最优估计理论和方法,即卡尔曼滤波技术,消除北斗三星无源定位数据中随机误差的方法。对华南沿海北斗三星无源定位实验数据进行滤波处理,结果表明:(1)北斗三星无源定位单点定位精度在纬度方向为±58m,经度方向为±4.3m,经卡尔曼滤波后其单点定位精度在纬度方向为±43m,经度方向为±3.6m;(2)北斗三星定位误差主要分布在纬度方向;(3)通过卡尔曼滤波可使北斗三星无源定位精度提高25%。  相似文献   

无人机载线阵摆扫CCD影像几何校正     

张艳  王涛  赵亮  刘颖  徐青  孙雷 《海洋测绘》2006,26(5):65-67,78

针对无人机载线阵CCD传感器摆扫成像的技术特点,利用GPS/INS组合导航系统提供的导航遥测数据,对无人机载的线阵摆扫CCD影像建立了严格的成像模型,并设计了详细的几何校正流程。实验结果证实采用文中的成像模型和几何校正流程,可获得正确、高精度地理编码的线阵摆扫CCD正射影像。  相似文献   

GIS新引擎——“真图”数据解决方案     

李德仁  ;郭晟  ;胡庆武  ;刘守军  ;魏建魁 《测绘软科学研究》2008,(3)

提出了一种基于移动测量系统技术的"真图"数据解决方案。一方面极大地丰富了GIS数据源,另一方面通过相应的真图影像数据管理软件及开发包扩展GIS功能,为各行业应用提供了地理信息数据解决方案。  相似文献   

对提高导航型GPS定位精度之工作方法的探讨     

周新力  范志勇  羊春华 《测绘科学》2008,33(3):87-89

论文主要介绍了导航型GPS坐标转换参数的计算方法和测量误差的改正方法。该方法的要点是通过实测多个公共点来计算坐标转换参数,以此获得较好的转换精度;并进一步对观测结果加以误差改正,从而提高其定位精度。  相似文献   

GALILEO系统仿真与分析     

牛飞  韩春好  陈金平 《测绘科学》2008,33(5)

本文着重阐述了GALILEO仿真系统星座和误差模型的构建过程,利用该系统进行DOP值分析并通过定位解算验证了GALILEO系统的性能指标。通过与GPS系统性能指标进行比较,得出GALILEO系统的星座设计具有较好的DOP值分布特性,定位精度优于GPS定位精度。在进行差分定位时,其误差贡献比较大的是接收机噪声和卫星钟差,因此提高差分定位的关键是降低接收机的噪声水平和提高卫星钟差预报精度。  相似文献   

Galileo开放服务导航电文特点分析     

CHEN Nan  YANG Li  DING Qun 《测绘学院学报》2008,(5)

介绍了Galileo系统开放服务接口控制文件中导航信号及电文的概况,并在如何满足导航电文中各种不同参数数据的时效性、如何缩短用户接收机导航数据接收时间、如何支持多系统互操作等方面对其特点进行了分析介绍。  相似文献   

地图误差对地图匹配质量的影响     

LIU Zhi-de  CHEN Jia-bin  DING Lu  SONG Chun-lei 《测绘学院学报》2008,(5)

高精度的数字地图是正确匹配车辆位置的基础。详细分析了地图数据的地理误差和拓扑误差的误差形式,路网数据模型的常见误差因素和改进策略,最后介绍了不同地图匹配算法对地图质量的敏感性和可行性。根据可能出现的误差对现有数字地图和匹配算法加以改进,弥补了原有数字地图带来的不精确缺陷。跑车实验证明,考虑了数字地图误差影响的匹配算法可以明显提高定位精度,减小车辆定位误差。  相似文献