Scheme design of SINS/GNSS autonomous navigation for launch vehicle

A SINS/GNSS autonomous navigation scheme is proposed for launch vehicle.Before lifting off,the gravity integral analytic coarse alignment method and Kalman filter fine alignment method were applied to realize the initial alignment of the strapdown inertial unit.After lifting off,the feedback information of SINS/GNSS Kalman filter integrated navigation was adopted to modify the vehicle's attitude,velocity and position information in real-time.By such a way,the autonomous navigation of launch vehicle is realized without external optical aiming device.Simulation results indicate that the level angle error is less than 0.01°,and the azimuth angle error is less than 1.5°.By the SINS/GNSS integrated navigation modification,the attitude error is less than 0.2°,the velocity error is less than 0.4m/s,the position error is less than 40m.The Monte Carlo simulation results with all the errors taken into account meet the accuracy requirements of launch vehicle.The proposed scheme has significant engineering application value.