Abstract:

An alignment method with inertial frame based on gravity information was described. On this basis, the strapdown inertial navigation system(SINS) error equations which use the geocentric inertial frame as the navigation reference frame were deduced. A state model which matches the inertial frame alignment algorithm was established, and a novel SINS alignment algorithm based on inertial frame filtering for marching vehicles was proposed. Computer simulation results demonstrate that the initial alignment algorithm based on inertial frame filtering for marching vehicles can solve the problem of large interference angular velocity. Realtime filter scheme can further reduce the effect of the noise and improve the accuracy of initial alignment. Besides, compared with the alignment algorithm based on geographic frame filtering, it simplifies the model and reduces the computational complexity.

Key words: information processing, strap-down inertial navigation system, initial alignment, inertial frame, Kalman filter, in marching