Effects of Non-orthogonal Scheme on Error Modulation of Single-axis Rotating Strapdown INS

Abstract

To improve the accuracy of strapdown inertial navigation system(SINS), a non-orthogonal installation scheme of inertial sensors was put forward for single-axis rotating SINS in this paper. Firstly, the principle of single-axis rotation modulation technology was expounded based on the error model of inertial sensors. Then, the effects of non-orthogonal scheme upon rotating modulation were analyzed theoretically, which show that the equivalent error magnitudes vary with angles between sensitive axes of inertial sensors. Finally, the simulation was performed. Experimental results show that the velocity error reduced from 1.91m/s to 1.03m/s in north and from 1.95m/s to 1.08m/s in east, and the positioning accuracy improved from 7.32 n mile to 2.00 n mile in north and from 5.06 n mile to 1.70 n mile in east within 24h when suing the new scheme.