A Perfect Alignment Method of SINS/GPS in High-Dynamic Condition

Abstract

Aiming at the problem that the navigation system of guided projectile will work after launch and the initial parameters of system will be determined on the condition of high speed and high dynamic, a new alignment method is proposed. The process of alignment is divided into two parts. In coarse alignment stage, proposes an estimator for the initial alignment of a strapdown inertial attitude reference system using IMU measurements with GPS aiding for moving-base alignment. The formulas of the coarse alignment method were derived which could solve the attitude of the flight by specific force equation using the velocity measured by GPS and specific force measured IMU. And then, in fine alignment stage, using small angle error model and Kalman Fliter based on UT transform to estimate and correct the navigation error. The performance is compared by a simulation system, which the precision is verified through computer simulation. Results show that this method has a good performance in accuracy.