Research on calibration of fiber optic gyro units

In order to satisfy the calibration precision of fiber optic gyro units used in the strap-down inertial navigation system, this paper proposes a combination calibration method. First, according to the characteristics of high precision turntable positioning, a static discrete calibration is proposed. It makes use of the Earth´s rotational speed and a special calibration path to calibrate the fiber optic gyro ´s scale factor, installation error and zero drift and so on 12 error parameters. Then the systematic calibration revises the results of static discrete calibration. Under the static base, the systematic calibration makes the speed error and the misalignment angle as the observable and uses the kalman filtering techniques to estimate the discrete calibration errors and amends it. Simulation results show that the combination calibration method can greatly improve the calibration precision of fiber optic gyro units.