The Rate Of Partial Frequency Laser Sins Initial Alignment Method

With the development of inertial technology, laser gyro with high precision and high performance has been widely applied in the Strapdown Inertial Navigation System(SINS). But because of its lock-in phenomena, it must possesses frequency biasing technique. The rate biased technique can virtually decrease all the walk error and improve its working precision. It is one of the central technique of the high-powered laser gyro SINS. The paper studies initial alignment of the SINS based on rate biased ring laser gyro. First of all, analyzes the structure and principle of laser gyro and compares one with another on frequency biasing technique;and then designs the structure of SINS based on rate biased ring laser gyro, founds the system output equation;according to the rotation characteristic of rate bias platform, considering the scale errors of inertial instrument and the influence of rate bias platform, extending the normal system error equations, derives its system error equations and achieves initial alignment with kalman filter method;analyzing the errors of inertial instrument, considering the complexity of operation at the normal SINS error calibration and the incompletion of kalman filter estimation, founds a suitable error calibration method for the SINS based on rate biased ring laser gyro and realizes the higher estimation precision and the convenient operation process;and then through one hour simulation test of navigation, analyzes the changing of the system error and the precision at the navigation state. The simulation results show that the lesser system error and the better navigation precision is obtained;at last, discusses the application of the SINS based on rate biased ring laser gyro to some projects which provides future work with some experience and reference.