A fast calibration method of the biases of IMU based on norm observation

DOI:	10.11809/bqzbgcxb2023.07.035
Keywords:	IMU bias calibration; norm observation; attitude error
Abstract:	Aiming at the requirement of short time and high precision for the calibration of the biases of inertial measurement unit (IMU) in the field test, this paper proposes a fast calibration method for biases of IMU based on norm observation. The modular equation of measurement information of the three axis gyro and the angular velocity of the earth and the modular equation of measurement information of the three axis accelerometer and the local gravitational acceleration are respectively constructed. Nonlinear equation groups for biases are constructed based on the static one minute measurement information of the three sensitive axes stretching roughly upwards in the IMU. Through the genetic algorithm, the minimum value search is used to obtain the calibration result of the IMU biases. The results show that it takes the IMU biases calibration only about 3 minutes without the use of an indexing mechanism. It is only necessary to keep each sensitive axis roughly upwards and static for 1 minute, which is suitable for fast calibration of the biases of the IMU in the field. The validity of the proposed method is verified by simulation and experiments, and the deviation between the calculated value and the reference value is an order of magnitude higher than that of the corresponding accuracy of the IMU. Thus, the difference between the calculation result of the IMU biases and the reference value is within an allowable range, which validates the correctness and effectiveness of the proposed method.
Published:	2023-07-28
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