SINS/GNSS组合导航系统中激光多普勒测速仪参数估计

为了提高SINS/GNSS组合导航系统的全局性能,考虑加速度与高斯包络对激光多普勒测速仪的影响,提出SINS/GNSS组合导航系统中激光多普勒测速仪参数估计方法。通过分析SINS/GNSS组合导航系统工作原理,明确SINS/GNSS组合系统状态;采用预先梯度评估方法,对梯度方向进行估计迭代,以提高导航定位精度,将获取的方位偏差代入卡尔曼滤波器中进行处理,保证SINS/GNSS组合导航系统实际应用的可靠性;获取对应费希尔信息矩阵,采用正弦信号的圆频率估计方差获取CRLB;分析激光多普勒测速仪测速过程中存在的问题;在信号成分参数分解前提下,将各距离门回波近似看作多个Chirp分量合成信号,对距离压缩后的数据实施自适应Chirplet分解,完成激光多普勒测速仪参数估计。实验结果表明:所提方法能够得到准确的参数估计数值,为SINS/GNSS组合导航系统的有效应用提供理论参考。

Parameter estimation of laser doppler velocimeter in SINS/GNSS integrated navigation system

In order to improve the global performance of SINS/GNSS integrated navigation system,considering the influence of acceleration and Gaussian envelope on laser Doppler velocimeter,a parameter estimation method of laser Doppler velocimeter in SINS/GNSS integrated navigation system is proposed. By analysing the working principle of the SINS/GNSS integrated navigation system,the SINS/GNSS integrated navigation system’s status is clarified. The gradient direction estimation iteration is adopted to improve the navigation and positioning accuracy. The azimuth deviation obtained is processed in the Kalman filter to ensure the reliability of the SINS/GNSS integrated navigation system’s practical application. The corresponding Fisher information matrix is obtained In this paper,the circular frequency estimation variance of the sinusoidal signal is used to obtain CRLB. The problems existing in the speed measurement process of laser Doppler velocimeter are analyzed;under the premise of signal component parameter decomposition,each range gate echo is approximately regarded as the composite signal of multiple chirp components,and the adaptive Chirplet decomposition is implemented to complete the parameter estimation of laser Doppler velocimeter. The experimental results show that the proposed method can obtain accurate parameter estimation values,which provides a theoretical reference for the effective application of SINS/GNSS integrated navigation system.