低成本车载GPS/INS组合导航速度更新算法

Velocity Update Algorithms of Low-Cost GPS/INS Integrated Navigation in Land Vehicle System

针对低成本GPS/INS组合导航系统无法观测得到多普勒值获得速度更新的问题,介绍了相邻历元伪距差分、载波相位差分以及附加辅助信息对INS进行速度更新的过程,并对这几种算法进行了分析和比较。实测算例表明,在市区车载环境中载波相位差分易受到外界干扰,周跳频繁,速度更新不可靠;伪距差分尽管也会受到干扰,但是影响不大,速度更新精度较高;而附加辅助信息速度更新精度较低,但是这种算法在GPS不可用时,仍然能够进行速度更新。

In low-cost GPS/INS Integrated Navigation System,the Doppler observations can not be obtained for updating the velocity of INS navigation.Here three velocity update algorithms of psedorange differential and carrier phase differential between two epoches and adding auxiliary information were introduced,analyzed and compared.By calculation,it was shown that cycle skips occured frequently in carrier phase differential for it was disturbed by the complicated condition and the velocity update was not reliable,psedorange differential could be disturbed slightly and the precision of the velocity update was higher,the precision of the velocity update of adding auxiliary information was lower but it was not disturbed by the complicated condition and the velocity update was carried out even when GPS was in outage.