旋转惯导中加速度计尺寸效应误差分析及补偿

 对旋转调制惯导转位过程中系统精度受加速度计尺寸效应影响的问题进行了研究。通过分析尺寸效应引起惯导系统(INS)导航误差的机理,推导了尺寸效应作用下加速度测量误差与速度误差的解析表达式。根据理论分析结果,分别给出了以速度误差和加速度误差作为观测量进行尺寸参数辨识的方法,并进行了必要讨论。结合旋转惯导转位过程中的速度误差特征,选取加速度测量误差为观测量对尺寸参数进行试验标定,尺寸参数辨识精度优于1.29 mm(1σ)。在此基础上给出了尺寸效应误差补偿方法,并在不同初始方位下对补偿效果进行试验验证,结果表明,通过尺寸效应补偿可以有效提高旋转惯导转位过程中的速度精度。

Error Analysis and Compensation of Size Effect in INS with IMU Rotation

The precision degradation caused by size effect during indexing in inertial navigation system (INS) with inertial measurement unit rotation for error modulation is investigated. Moreover, the mechanism of system performance influenced by size effect is studied and expressions of acceleration measurement error and velocity error due to size effect during indexing is deduced. Based on theoretical analysis, two techniques utilizing velocity error and acceleration measurement error as observables for the calibration of size effect parameters are presented and some necessary issues are discussed. By considering the error characteristics in inertial navigation system with inertial measurement unit rotation, the acceleration measurement error is selected to calibrate size effect parameters. The identification precision is better than 1.29 mm (1σ). A useful method to compensate the size effect error is proposed and navigation experiments under different initial azimuths are carried out in order to verify its validity. Experiment result indicates that after compensation, velocity error in the process of indexing is effectively suppressed.