针对常见组合导航系统在隧道、峡谷、森林等卫星信号较弱甚至出现失锁状况的地区,定位精度会迅速下降的问题,设计了北斗/捷联惯导(SINS)/里程计(OD)组合导航定位终端。终端设计以OMAP-L137处理器为核心,包括北斗、SINS、里程计、4G通信和电源等模块。数据处理部分以北斗导航接收机和根据SINS/OD推算分别得到的伪距、伪距率之间的差值作为量测值,使用拓展卡尔曼(EKF)滤波算法进行数据融合与误差估计。实验结果表明,北斗/SINS/OD组合导航定位终端在卫星失锁情况下行驶总里程5 km时最大位置误差为46.82 m,误差漂移为0.94%,能够有效解决卫星信号受遮蔽导致定位精度下降的问题,实现平滑载体运行轨迹并提高导航定位精度。

Aiming at the problem that the positioning accuracy of common integrated navigation systems will decline rapidly in areas with weak satellite signals such as tunnels,canyons,forests,etc.,a Beidou/strapdown inertial navigation (SINS)/odometer (OD) integrated navigation and positioning terminal is designed.The terminal design takes OMAP-L137 processor as the core,including Beidou,SINS,odometer,4G communication and power supply modules.The data processing part takes the difference between the Beidou navigation receiver and the pseudo range and pseudo range rate calculated according to SINS/OD as the measured value,and uses the extended Kalman filter (EKF) algorithm for data fusion and error estimation.The experiment results show that the maximum position error of Beidou/SINS/OD integrated navigation and positioning terminal is 46.82 m and the error drift is 0.94% when the total mileage is 5 km when the satellite is unlocked,which can effectively improve the problem of positioning accuracy decline caused by the obscuration of satellite signals,smooth the vehicle trajectory and improve the navigation and positioning accuracy.