正六面体工装误差对光纤惯组加速度计零偏标定精度影响分析

研究了利用大理石平板正六面体工装对光纤惯组进行标定时,工装误差对标定精度的影响。首先建立了标定模型,设计了12位置法的标定方案与解算方法,其次分析了工装误差对标定影响的量化关系,并提出减小误差的标定解算方法,最后对理论分析结果进行仿真验证。仿真结果表明,当长宽高为400mm的工装平面度、垂直度、平行度误差均为0.04时,加速度计零偏的标定误差达到0.0001g,与工装误差角大小量级相当。用12位置二向法解算零偏可减小该误差影响。

Analysis on the Influence of Cube Fixture Error on Calibration Accuracy of Accelerometer Bias in FOG IMU

The effect of fixture errors on FOG IMU calibration accuracy is studied base on a calibration method using marble slab and cube fixture. First, the calibration mathematical model is established and a twelve-position calibration and resolution method is designed. Then, the quantitative relationship between fixture error and calibration results is analyzed, and a calculating method for reducing the influence of the cube fixture error is proposed. Finally, the theoretical analysis results are verified by simulation. Simulation results show that, with a cube fixture measuring 400mm on each side and having the same error value of 0.04 in flatness, verticality and parallelism, the calibration error of the accelerometer bias can reach 0.0001g, which is of the same order of magnitude as the cube fixture error angle. The calibration error can be reduced by the twelve position and two direction method.