Study On Calibration And Transfer Alignment Of Strapdown Inertial Navigation System

Calibration errors and transfer alignment of SINS are the key technology. Inertial components errors account for about 90 percent of system errors. It can be seen that inertial components determines the precision of SINS Study of transfer alignment is based on the error equation. Therefore, Calibration studies are necessary. More and more carriers have make use of aligned inertial guidance system to pass under the Moving Base Alignment. The increase of observational information makes alignment better. So that alignment time is shortened and the accuracy is improved. For Hypersonic Vehicle, calibration in the pre-flight and the SINS Alignment in flight are necessary in order to play its speed and the advantage of short reaction time.The paper focuses on several aspects of the research:As the fight characteristics of Hypersonic Vehicle, which speed and acceleration are large, this presents a higher demand to inertial components of SINS. Calibration must be make before fight. The thesis presents the multi-position calibration method of the inertial components of SINS. On this basis, the RLS filtering is used for the calibration. Considering the laser gyro is sensitive to temperature's change, the thesis establishes the temperature error model of laser gyro bias by temperature experimental data.In order to show the advantage of transfer alignment, the alignment model is established under the Stationary base. Firstly, the error equations are derived in detail. And then, the thesis creates the models of coarse alignment and simplified fine alignment, and uses the improved adaptive filtering to simulation in comparison with routine filtering.Toward Transfer alignment, the paper mainly makes researches on transfer alignment in matching method. Firstly, the system state equation transfer alignment is stated. According to the different matching alignment scheme, the system measurement equations are stated by the velocity matching scheme, velocity plus attitude matching scheme, velocity plus angular rate matching scheme, the velocity matching scheme considering lever-arm effect. At last, according to the fight characteristic, the paper makes the corresponding numerical simulation under the conditions of uniform level fight and accelerated level fight.The results of simulation show that the models are correct and effective, and the paper has certain practical value.