Study on Strapdown Inertial Navigation Initial Alignment Method Based on Uniaxial Rotation Modulation

Initial alignment technology is one of the key technologies of strapdown inertial navigation system and its precision will affect the navigation result. In order to improve the accuracy of initial alignment and shorten the alignment time, this paper introduces the rotary modulation technology into the strapdown inertial navigation system, designs an IMU translocation scheme of continuous rotary alignment, expounds the principle of rotary modulation initial alignment, and establishes the static reference alignment error model for strapdown inertial navigation system based on Kalman filtering. The simulation results show that compared with the traditional single position alignment and two-position alignment, the scheme of rotational modulation initial alignment can improve the alignment accuracy effectively.