A hybrid grading calibration method of FOG-IMU and its experimental verification

There exist some problems in the fiber optic gyro inertial measurement unit(FOG-IMU) calibration, such as dependence on high-precision turntable, low precision, rigorous calibration condition and so on. Aiming at these problems, we propose a high-precision grading calibration method. Firstly, system parameters are calibrated by the discrete calibration method, in which the effects of the lever-arm are considered. Secondly, sensors' parameters are compensated effectively. Afterwards, the residual components of the IMU parameters are used as estimated objects and a 27-dimension Kalman filter is established by using velocity errors as observed quantities. The residual errors of coarse calibration will be estimated and compensated as well. Finally, results are validated through turntable experiments.