Research on Fast Self-alignment Method of SINS under Vehicle Jitter and Leveling Disturbance

Using the combination of simulation and actual measurement, analyze the impact of disturbances such as the jitter of the launch vehicle drive motor and the leveling motion of the launch vehicle on the output signals of the gyroscope and accelerometer, clarify the alignment error source of the SINS, and combine the error model to design based on the Kalman classical filter. For the algorithm's variable mode filtering scheme, a variable mode filtering alignment method using the output pulse threshold of the horizontal gyro is proposed, and the filtering method in the fine alignment stage is improved. Vehicle experiments show that the proposed variable mode filtering method has a simple algorithm and a small amount of calculation, and can effectively suppress dynamic disturbances such as engine jitter and vehicle leveling motion, improve the convergence speed of the azimuth error of the strapdown inertial navigation system, and reduce the azimuth misalignment angle estimate bias.