Improved Design of Two-point Calibration for Gimbaled INS

In order to enhance the precision and decrease the independence of exterior information,the two-point calibration independent of exterior course information in undamped navigation mode is proposed.ADRC(Active Disturbance Rejection Control)is applied in gimbaled INS comprehensive calibration.Based on INS error model of moving base,the ESO(Extended State Observer)is designed to estimate the error angle of INS platform,which is used to replace the exotic course information.Contrastive simulations are operated in both traditional and the new proposed two-point calibration ways.The simulation result shows that if INS operates complying with the new project,the estimation errors of northern and orientation gyro drifts respectively reduce to 5 % and 3.33 % while they are 122 % and 100 % when working in traditional way.It proves the availability of the new project.It indicates that the new project improves two-point calibration accuracy via decreasing the influence of maneuver on the platform horizontal precision.Besides,exterior course information is not needed anymore for northern and orientation gyro drifts estimation.