Calibration method for the laser gyro strapdown inertial navigation system based on norm-observation

In order to reduce the influence of turntable's errors on the calibration accuracy of SIMU, the position and the rate test plans of the regular icosahedrons-12 points were designed by using norm observation of the specific force and the angular velocity vectors. Firstly, the twelve static positions were utilized to calibrate the accelerometers' biases, scale factors and mounting errors in the gravity field. Secondly, using single-axis rate and double-axis position mode, namely the outer axis of the three-axis turntable was working in angular rate mode, both the inner and the middle axes were in the twelve positions, the RLGs' biases, scale factors and mounting errors were calibrated. At the same time, unification of the accelerometer and the gyro parameter coordinate systems was realized by using the SIMU frame coordinate system. Finally, simulation analysis shows that this method can effectively suppress the influence of turntable's errors on the calibration results of SIMU, the relative calibration errors of the scale factors of the accelerometers' and the gyros', and the calibration errors of the installation error matrix are less than 10-5, the calibration errors of accelerometer biases are less than 10g, the calibration errors of gyro biases are less than 0.01()/h which are in the same order of magnitude of the measurement noises, in the situation that perpendicularities between the turntable's adjacent axis lines are at the arc second level and that angular position errors are less than 1'.