SINS/GPS紧耦合组合导航

SINS / GPS tightly-coupled integrated navigation

针对可用星数目小于4情况下,SINS/GPS松散组合导航必须转为纯惯性状态,无法解决纯惯性导航参数误差发散的问题,提出了以导航星伪距和伪距率为观测量的紧耦合SINS/GPS组合导航方案。建立了紧耦合系统的数学模型,搭建了硬件系统,并应用于工程实践。车载试验结果表明:当可用星数目小于4时,紧耦合系统定位的纬度误差、经度误差小于100 m,且与导航时长无关,而纯惯性系统定位误差随时间发散,0.5 h纬度误差为1000 m,而1 h时纬度误差增至2000 m左右;当可用星数目大于等于4时,SINS/GPS紧耦合模式其经、纬度误差小于10 m,高程误差小于20 m,而松散组合时误差约为前者3倍。

The SINS/GPS loose-coupled system has to work in the pure inertial state if less than 4 satellite are available,thus its parameter errors would be unbounded.In view of this problem,a tightly-coupled SINS/GPS integrated navigation scheme is put forward which takes the pseudorange and pseudorange rate of GPS as the observations.The model of tightly-coupled system is set up,and the technology is realized in practical application.The vehicle test results show that： when number of usable navigation satellites is less than four,the latitude and longitude errors of tightly-coupled are both smaller than 100 m and has nothing to do with the navigation time;and when it is equal or more than 4,the latitude error is about 1000 m in half an hour and about 2000 m in an hour.When the usable satellite number is more than four,latitude and longitude errors of tightly-coupled system are both smaller than 10 m,and the altitude error is smaller than 20 m,which are significantly less than those of loose-coupled system.