GNSS/SINS组合导航中多路径效应的识别与抑制算法

Identification and Suppression Algorithm of Multipath Effect in GNSS/SINS Integrated Navigation

针对GNSS/SINS组合导航系统中,GNSS定位易受多路径效应影响的问题,提出了一种多路径效应识别与抑制算法。通过设计姿态检测与χ^(2)检验相结合的两层多路径效应识别方法,实时检测GNSS输出结果的可靠性和GNSS/SINS二者定位的一致性。将提出的抗野值自适应滤波算法用于对多路径误差的抑制,当检测到GNSS受多路径效应影响时,通过残差加权减小异常量测量在量测更新中的比重;当GNSS定位正常时,通过限定记忆指数加权的方式计算残差协方差的极大似然最优估计,并采用渐消滤波提高滤波器的调节能力。通过实际跑车试验验证了该算法能够有效抑制GNSS多路径误差,具有较高的导航精度与自适应能力。

Aiming at the problem that GNSS positioning is easily affected by multipath effect in GNSS/SINS integrated navigation system,a multipath effect recognition and suppression algorithm is proposed in this paper.The reliability of GNSS output results and the consistency of GNSS/SINS positioning are detected in real time by designing a two-layer multipath effect recognition method combining attitude detection andχ2 inspection.The proposed anti-outlier adaptive filtering algorithm is used to suppress the multipath error.When it is detected that GNSS is affected by multipath effect,the proportion of outlier measurement in measurement update is reduced by residual weighting.When GNSS positioning is normal,the maximum likelihood optimal estimation of residual covariance is calculated by limiting memory index weight,and the fading filter is used to improve the adjustment ability of the filter.The actual vehicle experiments show that the proposed algorithm can effectively suppress GNSS multipath error,and has high navigation accuracy and adaptive ability.