YU K, ZHANG Y R, ZHANG Q Z, et al.Study on observability of Reduced IMU/GPS with magnetometer aiding[J].Journal of Henan Polytechnic University(Natural Science) ,2022,41(6):77-83.

doi:10.16186/j.cnki.1673-9787.2020110099

Received:2020/11/30

Revised:2021/01/18

Published:2022/11/25

Study on observability of Reduced IMU/GPS with magnetometer aiding

YU Ke1, ZHANG Yunrui1, ZHANG Qiuzhao1,2, YU Zhangjun1

1.School of Environment and Spatial Informatics， China University of Mining and Technology， Xuzhou  221116， Jiangsu，China；2.Jiangsu Key Laboratory of Resources and Environment Information Engineering， China University of Mining and Technology， Xuzhou  221116， Jiangsu，China

Abstract:In order to solve the problem of poor observability of the Reduced IMU/GPS integrated navigation system，the estimability of the parameters of Reduced IMU/GPS integrated navigation system was analyzed by means of basic differential equations of motion.And the reason why some parameters could not be estimated under specific motion conditions is given.In view of the strong correlation between the vertical axis gyro drift error and the heading angle error，it was proposed to add the new information update value of the magnetic sensor to the observation coefficient matrix.The heading angle error was turned into a directly measurable parameter to solve the problem of poor observability of the integrated navigation system caused by Reduced IMU.Finally，the method in this paper was verified qualitatively and quantitatively through four sets of simulation experiments.Experimental results showed that under different motion conditions，the horizontal accelerometer drift error of the front and rear integrated navigation system assisted by magnetic sensors could converge quickly.The drift error of the vertical axis gyroscope could converge to the true value faster after introducing the magnetic sensor.The spectral condition number observability method also showed that the observability of the vertical axis gyro drift error had been improved considerably after the introduction of the magnetic sensor.

Key words:Reduced IMU;observability;spectral condition;magnetometer aiding;integrated navigation system

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