Abstract:

The error modulation principle of a strapdown inertial navigation system (SINS) based on singleaxial rotation is presented. To finish the coarse alignment of SINS with inertial measurement unit (IMU) rotated, the essential distinction and applicability between the analytic coarse alignment and the inertial coarse alignment are analyzed contrastively. According to the nature that inertial coarse alignment is a dynamic process, the inertial coarse alignment is quoted in the rotary SINS, the theoretical derivation and the mathematical analysis are also presented. By simulation, the process of coarse alignment with IMU rotary is analyzed on the typical threeaxial rotation, and the results are compared with the situation of nonratation. The simulation results show that the constant error of sensors is modulated by the IMU rotated on the condition of the inertial coarse alignment, the precision of coarse alignment can be improved effectively.