考虑转台定位误差时的快速自对准方法研究

捷联惯导初始对准精度直接影响到惯导系统的工作精度,传统自对准方法对转台定位精度要求较高,转台存在定位误差时严重影响自对准精度。提出了一种考虑转台定位误差条件下的捷联惯导快速两位置自对准方法,根据对准位置与旋转过程中的惯导相邻时刻输出信息小幅慢变的特点,通过引入中间坐标系,实现实际旋转角度的精确跟踪和导航误差实时更新计算,辨识出初始姿态角误差,并根据对准精度要求对辨识结果迭代修正,从而实现动态条件下的高精度寻北。对该算法在静、动态环境下的寻北性能进行了实验验证,实验结果表明:静态环境下寻北精度的1倍标准差为18.3248″,动态环境下寻北精度的1倍标准差为32.633 07″,对准精度与计算速度均满足要求,能够有效克服转台定位误差对自对准精度的影响,具有一定的工程应用价值。

Research on quick self-alignment method considering turntable positioning error

SINS initialization alignment precision influences INS precision,conventional self-alignment method requires high precision turntable,turntable positioning error influences alignment precision seriously.A method of SINS two-position self-alignment considering turntable positioning error is put forward,in the alignment position and turn process,considering the characteristic that IMU conjoint output information changes slowly.Through introducing inter-mediate coordinate system,precise tracking of actual turn angle and real-time calculation of navigation error are realized,initialization gesture angle error is identified,result is revised repeatedly until satisfied alignment precision request.This algorithm’s northseaking precision in static state and dynamic condition is validated.Test results show that northseaking precision in static state condition is 18.3248″(1σ),northseaking precision in dynamic condition is 32.63307″(1σ),this method overcomes impact of turntable positioning error,alignment precision and calculating speed satisfy alignment request,which is of great value for project application.