An online calibration method for the temperature error of accelerometer bias of RINS under a new rotation strategy

Abstract The rotational inertial navigation system (RINS) modulates horizontal sensor errors by rotating the inertial measurement unit (IMU) around the vertical axis. In applications demanding high azimuth accuracy, it is essential to mitigate azimuth errors caused by vertical sensor inaccuracies through horizontal rotational modulation. Therefore, this paper proposes a novel rotational strategy that rotates the IMU around the horizontal east axis. A challenge with this approach is that constant biases of the eastward-facing inertial measurement sensors cannot be modulated. This issue is particularly pronounced during long-duration navigation, where accelerometer bias varies with temperature, leading to significant velocity oscillation error and positioning error. To address this problem, this paper primarily investigates methods for the online calibration and compensation of temperature-related errors of eastward accelerometer bias under this new rotational strategy. Simulation and experimental results demonstrate that using the proposed method significantly reduces the velocity oscillations and improves the navigation accuracy of the RINS.