Abstract:

In order to improve the precision of long time navigation for single axis rotary strapdown inertial navigation system, an accurate method to calibrate the axial gyro drifts is proposed. The influences of the axial gyro drifts and the angle error of the initial attitude and heading on the latitude and longitude of the system are analyzed under the static base condition. The horizontal damping network is introduced into the navigation algorithm to suppress the Shuler oscillation error. A mathematical model is established to connect the error of latitude and longitude with the axial gyro drifts and the angle error of initial heading, and in addition a reasonable calibration flow is designed, in which the least square method is used to calibrate the axial gyro drifts accurately. Mathematical simulations and actual system verification experiments are carried out, and the results show that when the gyro drifts error is 0.01(°)/h, the identification precision on the axial gyro drifts can reach 0.001(°)/h after 12.5 h precise calibration, and the positioning precision of the SINS is better than 1.5 n mile/48 h.