Online calibration method based on dual-axis rotation-modulating laser gyro SINS

Traditional calibration methods require a three-axis high precision turntable, which is unable to meet the demands of online calibration. Hence, based on the structural features of dual-axis rotation modulation laser strap-down inertial navigation system, this paper proposes an online calibration method by taking the velocity errors and the position errors as measurement information. In this paper, the error model of inertial navigation system is established, and a 30-dimension Kalman filtering model is derived in which the state variables include the gyro constant error and the gyro scale factor error and the gyro installation error angle, the accelerometer constant error and the accelerometer scale factor error and the accelerometer installation error angle. In order to identify error parameters comprehensively, an appropriate calibration route is designed. According to the route, the simulation shows that all error parameters of laser gyros and accelerometers can be identified and calibrated precisely. This method satisfies the demands of online calibration and has a great engineering significance.