Research On Moving Base Alignment For Vehicular Strapdown Inertial Navigation System With Ring Laser Gyroscope

With the growth of national economy and development of national defence,the Strapdown Inertial Navigation System(SINS) has an increasingly widespread application in many fields.As one of the key techniques of SINS,initial alignment plays an important role in the performance of SINS.This paper studies on the theory and experiment of moving base alignment for RLG SINS.The application of kalman filter is emphasized during the discussion.The main work done in the paper is as follow:Firstly,the theory of moving base alignment and kalman filter are introduced in detail.Then, GPS-aided SINS is set up for moving base alignment.After that,the software for data-collecting and simulating are developed,and the original data collected from GPS and SINS on moving base are used for off-line simulating.Finally,the main factors which affects the result of initial alignment are discussed,and the basic method of moving base alignment is improved.In theory,the accurancy and speed of initial alignment can be improved by the motion of platform when some conditions are satisfied.But in fact,the motion also brings extra errors and disturbs.According to the experimental results,initial alignment on moving base gets a lower accuracy and a comparable speed compared to that on stationary base.The moving base alignment can be completed in 5-10 minutes,while the horizontal error angle gets an accurancy of 40″(1σ),and the azimuth error angle gets an accurancy of 4′(1σ).