Research on integrated alignment of rotary strapdown inertial navigation system

The initial alignment accuracy of strapdown inertial navigation system (SINS) is limited by the gyro drift and accelerometer bias, and the integrated alignment is generally used to diminish the error of initial alignment. In this paper, a reasonable dual-axis rotation scheme is designed to improve the observability degree of rotary strapdown inertial navigation system, and a novel integrated alignment method with external velocity and attitude information is proposed based on the previous method with velocity information. Simulation results show that the estimation speed of platform misalignment angles (primary reflects on heading misalignment angle) in the novel method is faster than in the previous method, and the estimation accuracy is much higher. The new scheme should be the preferred one if conditions permit.