Research On Rotating Modulation Techniques Of Rlg Sins

SINS has many advantages, such as high reliability, simple structure, low cost and so on. But SINS also has highlighted shortcomings of low navigation accuracy during long time. The main factors that affect navigation accuracy of SINS, include components errors, installation errors, algorithm errors and calculation errors. If gyro drift which the greatest impact on navigation accuracy of SINS can be compensated during the navigation process, more precise SINS can be got without improving the performance of inertial components.The current many of international advanced navigation system using rotating modulation techniques to automatically compensate output errors of the inertial measurement unit(IMU).This paper analyzes the principle of rotating modulation techniques of RLG SINS and different output forms of the installation error, scale factor error, gyro drifts and accelerometer bias of RLG SINS in detail during the rotation. In order to compensate the errors, the writer analyzes a classical four-position rotation plan of Sperry, and design single-axis rotation plan and biaxial rotation plans. Angular motion is frequent in the course of rotating modulation, so the errors equations were analyzed. And the result of computer simulation consistent with theoretical analysis. Rotating modulation techniques can improve the precision of navigation during long time.Because of rotation modulation RLG SINS's rotating bodies, multi-position initial alignment is possible. In this paper, the writer reserch multi-position initial alignment, the comparition of the results of two-position initial alignment and single-position initial alignment, show that the method of two-position initial alignment improved alignment accuracy, and laid the foundation of the higher navigation precision.