Rapid initial alignment under geographic latitude uncertainty of a single rotation AHRS on stationary base

Abstract

Principal analysis of state dynamic model in stationary alignment was done to formulate the practical problems when the model applied to the rotation modulation mechanization. In engineering applications, initial position error which affects alignment precision is inevitable. To improve attitude precision in alignment under geographic latitude uncertainty, a new dynamic measurement model of Kalman filter based on augmented measurement at turntable full rotation interval was introduced for a single rotation attitude and heading reference system (AHRS). Stationary alignment experiments were done on a postulate system utilizing rotation modulation mechanization to verify the effectiveness of the new dynamic measurement model. The experimental results show that the convergence rate of the new measurement model is sped and the estimation precision of the yaw angle and the geographic latitude are improved. The standard error of the yaw angle is 10" in 10 min, and geographic latitude uncertainty can be less than 300 meters in 10 min. Besides, estimation precision of the yaw angle will be little influenced when geographic latitude uncertainty is within 500 meters.