Analyze On Error Of Transfer Alignment On Moving Base And Alignment Method Research

Inertia navigation system（INS）is a key navigation system in modernintegration navigation systems, because of the large advantages onindependence and concealment. The initialization alignment is the foundationof INS navigation capability, it is always using transfer alignment while onmoving base. Due to various error factors, the attitude matrix set up afterinitialization alignment has much error. Because of the ship can’t make largeacceleration in level directions so as to bring out little observations, It wouldtook a lot time and made large errors in the rigor alignment procession, whileusing the traditional “velocity+Attitude” parameters matching method totransfer alignment. Meanwhile, thanks to the long cycle movement(less than0.1Hz) can’t be reduced and hard to ascertain the ship flexure, transferalignment on the ship base is a hot program in inertia navigation technologyresearch.This article made research on the transfer alignment technology on shipbase case. First, it established fundamentally parameters, coordinaterelationship and basic equations of inertia navigation, and then analyzed theerror factors of transfer alignment on moving base, which included IMUerrors, information of initialization alignment errors and computation errors,and made error models. analyzed the affection in transfer alignment by diversearm errors using Matlab/Simulink. It concluded that1)it can’t make transferalignment with large arm error;2)it has a strange relevancy between alignmentprecision and arm errors. it improved the alignment precision while less armerror;3)The effect of arm error reduces to a very low lever when there has aless than0.1m arm error, which would made it match the require of transferalignment on moving base. This article set up error equations on moving base, and then set up stateequations and Kalman filter observations using both “velocity+attitude” and“azimuth+velocity” parameters match methods. It proposed an transferalignment approach on moving base with introduced azimuths, the azimuthinformation would be introduced at the end of coarse alignment or processionof fine alignment. The transfer alignment Simulink results in represent seaenvironment concluded that it can achieve transfer alignment on ship basewhich introduced azimuths of1°at the end of coarse alignment or0.5°of BiasRepeatability and0.1（°） sRandom Walk Standard Deviation. The Simulinkresults make sure the feasibility of this two alignment approaches, andascertain the precision of the introduced azimuths.The transfer alignment error model brought in this article is concisionand truly, which reflects the error factors exactly. The transfer alignmentapproaches brought in this article afford instances for the transfer alignmenton ship base.