Improving the calibration process of inertial measurement unit for marine applications

Abstract

Marine navigation systems have very accurate sensors, such as 0.01deg/hr gyro drift stability and 0.1mg/year accelerometer bias stability. Common calibration methods and equipment do not meet the accuracy required. In this paper, a systematic method for calibration of an inertial measurement unit (IMU) for marine applications is proposed which is not based on the accuracy of the calibration turn table and only requires one specific plate to determine the initial attitude of the IMU and functions independently of the turn table. The first contribution of this paper is to derive a model for systematic calibration of IMU that expresses the rotation matrix error and velocity as a linear function of the calibration parameters at any time. As the second contribution, this paper proposes a calibration algorithm with only using an initial, specific plate. Using the actual data, it was found that the proposed algorithm provides a good estimation of the parameters.

Coarse alignment of marine strapdown inertial navigation system using the location of fitted parametric circle of gravity movement

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Figure 6.K. N. Toosi IMU FOG gyroscopes and Q-FLEX accelerometers (Rahimi et al, 2020), with details in Table 1

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“…For this research, the important parameters are specified in Table 1 and it is assumed that the calibration compensations are performed thoroughly on the sensors. This calibration compensation can be done using methods such as those in Rahimi and Nikkhah (2020). Another parameter is the time required to achieve the desired accuracy.…”