Pole assignment's influence on alignment performance of SINS gyrocompass

By analyzing the several common pole assignment schemes in gyrocompass alignment, this paper puts forward a new pole assignment scheme, which adopts a series connection structure for a second-order oscillation link and a critical damping link. The four poles are set on the same circle, which can guarantee the algorithm's tracking performance and alignment's high-accuracy. The comparison experiment results about the different pole assignment schemes in gyrocompass alignment were shown by using the data of the rocking base. It suggests that the new pole assignment method can track the attitude change of the car, and the whole alignment process of SINS can be finished within 180 s. The vehicle navigation tests were conducted in 6 levels of windy weather. The test results indicate that the new pole assignment scheme can overcome the interference of the wind, and improve the precision of the SINS alignment. Finally, the phase plane analysis is employed which suggests that the gyrocompass alignment can be used under the condition of large azimuth misalignment since the gyrocompass loop can also produce nonlinear driving torque to push the mathematical platform into navigation coordinate.