Integrated calibration method for dithered RLG POS using a hybrid analytic/Kalman filter approach

For improving the calibration precision of ring laser gyroscope (RLG) inertial measurement unit (IMU) with antivibration system, a novel integrated calibration method using a hybrid analytic/Kalman filter approach was proposed. An optimization analytic calibration method with four-direction rotations, based on three-axis turn table, was designed to coarsely calculate all the coefficients of RLG IMU mathematical error model. For further amending the remains of analytic calibration caused by an antivibration system disturbance and gyroscope drifts, a fine calibration method based on extended Kalman filter was proposed. It regarded the velocity errors as observation using a lever arm compensation technique. The experimental results show that the proposed integrated calibration method can improve the efficiency and precision of RLG position and orientation system which had been practically applied in airborne survey/mapping system.