陀螺随机漂移引起的惯导系统误差特性分析

为研究陀螺随机漂移作用下的惯导系统误差发散规律,当陀螺随机漂移为白噪声时,基于静基座下的惯导系统误差方程,得到了惯导系统误差的计算方法。基于白噪声的统计特性,理论推导了惯导误差方差的解析解,并分析了各因素对惯导系统误差的影响。基于理论推导公式,对白噪声作用下的惯导系统误差做了仿真计算。结果表明:在陀螺随机漂移作用下,惯导系统误差与航行纬度有关。方差中包含舒拉、傅科、地球三种周期振荡和非周期项。其中的非周期项与陀螺漂移率的方差成线性关系,同时是时间的斜坡函数;经度误差的方差中,三种周期性振荡受非周期项的调制作用,振荡幅值随时间线性增大。

Analysis of INS Errors Caused by Random Gyro Drifts

In order to study the error diverging rule caused by random gyro drifts,based on INS errors equations on stationary base,a feasible calculation project of INS errors is proposed if the random gyro drifts are white noise.The solutions of INS errors variances are deduced using white noise statistic trait.The influence of various factors on INS errors is analyzed as well.And simulation is carried out for the INS errors.The study results indicate that all INS errors are concerned with navigation latitude.The errors variances contain three kinds of periodical elements: Schuler,Foucault and earth seasonal fluctuations.They also include nonperiodic element which is linear with each gyro drift and time.Periodical elements of longitude error variance are modulated by the nonperiodic one,and the amplitudes of seasonal fluctuations are proportional to time.