Heading error of Strapdown inertial navigation system (INS) may be enlarged in some complicated road and vehicle conditions when maneuvering long time.An integrated navigation algorithm based on single INS (SINS) integrated navigation algorithm frame was presented.Integrated navigation was achieved through Kalman filter with 21 error states of the inertial measurement unit/distance transfer unit (IMU/DTU),which selected the difference between the displacement increment obtained respectively from the INS and the DTUas the observation term.Most errors of IMU/DTU integrated navigation system was canceled automatically by way of rotation and Kalman filter,which integrated information from the INS and the DTU.Precise position information and attitude information could be output without special conditions for marching vehicles.Some simulation experiments and vehicular tests were executed,which showed that the algorithm was able to achieve precise heading(attitude) and position.Potential accuracy was discovered.Rapid response capability,environmental adaptability and usability were improved greatly.

Under high dynamic circumstances, the size effect error caused by inner lever arm is an important error source of high accuracy strap-down inertial navigation system (SINS). The mechanism of size effect error is analyzed theoretically. The dynamic error model of inner lever arm is derived, and the calibration model is derived based on inner lever arm model and system error model. By using the velocity compensated with outer lever arm error as the observation, an inner lever arm calibration method based on Kalman filter is established. The experiment results show that the repeatability of inner lever arm parameter is better than 2 mm. In the rapid rotation test, the speed error is reduced by 90% with inner lever arm parameters compensation, and the navigation accuracy in the swing test is improvedsignificantly.