基于速度阻尼的双轴旋转式激光陀螺捷联惯导标定方法

Calibration method for two-axis indexing RLG-SINS with speed damping

惯性元件参数的长期稳定决定着惯导系统的精度,目前对于激光陀螺捷联惯导系统(RLG-SINS)主要是采用系统级旋转调制技术来实现高精度导航能力,同时系统级旋转也提高了初始对准精度以及惯性元件误差的可观测性。针对激光陀螺惯导系统惯性元件误差项的特点,同时结合分立式标定与系统级标定各自的优势,设计了一种水平阻尼模式下的Kalman滤波方案,利用双轴旋转机构,通过观测导航位置误差来实现初始对准以及部分惯性元件误差参数的标定,可以有效地减小惯性元件逐次启动误差对导航精度的影响。仿真结果表明,系泊状态零速度阻尼模式下工作4 h,可以标定出石英加速度计标度因数误差、零偏与激光陀螺零偏,共计9项误差参数。加速度计零偏估计误差小于2%,陀螺零偏估计误差小于8%,误差估计精度满足高精度惯性导航要求,该方法具备一定的工程实用性。

The long-term stability of inertial element parameters determines the accuracy of inertial naviga-tion systems, and the present laser gyroscope strapdown inertial navigation system (RLG-SINS) is mainly by means of systematic modulation techniques to achieve the capability of high accuracy navigation or improve the accuracy of initial alignment and the observability of inertial component errors. According to the inertial component error characteristics of RLG-SINS, and combining with the respective advantages of discrete calibration and systematic calibration, a Kalman filter scheme is designed in lever-damp mode to achieve the initial alignment and to calibrate parts of inertial component errors by observing navigation position errors and using two-axis indexing. This scheme can effectively reduce the influence of inertial component's each startup error on navigation accuracy. The simulation results show that the total nine error parameters (scale factor error and bias of the quartz accelerometer, laser gyroscope bias) can be estimated on mooring base during 4 h operation in zero-speed damping mode. The estimated error for accelerator bias is less than 2%, and the estimated error for gyroscope bias is less than 8%, meeting the demands of high accuracy inertial navigation, and showing that this method has certain engineering practicability.