Research On Deeply GNSS/SINS Integrated Navigation System Filtering Technology

In these years,the performance of navigation system need to be better and better in different fields.Inertial Navigation System and Global Navigation Satellite System are two main navigation systems which are used more widely.By a deeply combination of their navigation data,they can complement each other,and improve the accuracy and reliability of the whole navigation system.Thus,as a hot and difficult spot in navigation research,deeply SINS/GNSS integrated technology has significant meaning for navigation performance improvement.In this paper,baseband tracking algorithm and filtering algorithm of deeply SINS/GNSS integrated navigation syetem are researched and analyzed,the specific contents are as follows:Firstly,this thesis introduces the background of the deeply integrated navigation technology and its current development at home and abroad,summarizes the research significance and contents.According to the structure of the navigation message D1 in BDS,the characteristics and effects of NH code are analyzed.Based on the analysis of lever-arm effect among different sensors,this paper do research on the error compensation of lever-arm effect in deeply integrated navigation system.And I did some simulation experiment of carrier velocity.The error of baseband tracking loop is discussed.The contents above,are prepared for tracking algorithm and filtering algorithm design.Then,based on the analysis of general C/A code phase discrimination algorithm,aiming at improve C/A code phase estimation precision,using Maximum Likelihood Estimation(MLE),this paper mentioned an advanced phase discriminator based on MLE.By doing simulation experiments,and comparing C/A code phase discrimination errors,proves that this advanced algorithm is effective.Later,aiming at the disadvantage of Sage-Husa algorithm when the carrier does high-dynamic movement,this thesis designed this advanced Sage-Husa self-adaptive filtering algorithm which based on exponent correction factor.Meanwhile,aiming at the disadvantage of fading self-adaptive filtering algorithm when the deeply integrated navigation system in high-dynamic situation,this thesis designed this advanced fading self-adaptive filtering algorithm which based on exponent fading factor.This thesis starts in researchs on the frame of the deeply integrated navigation system.Based on the deep level math derivation of the deeply integrated navigation system,this paper designs the integrated navigation filter,including state equation and observation equation.Meanwhile,I designed an advanced Sage-Husa self-adaptive filtering function and an advanced self-adaptive fading Kalman filter,which are mentioned above.By using carrier path dynamic simulation and doing experiments on Matlab,proves that these advanced filter functions are efficient and have good navigation results.And the advanced Sage-Husa self-adaptive filtering algorithm has better effects.At last,based on research and study of software navigation receiver and the frame of the deeply integrated navigation system,this paper designs the deeply integrated navigation system software experiment platform by Matlab,and the deeply integrated navigation system hardware experiment platform based on FPGA/DSP.Then,based on this hardware experiment platform,aiming at eliminating pseudorange jumping change caused by different periods of different BDS satellite navigation message subframe,this thesis designs an advanced pseudorange measurement method.Through the actual test on the hardware experiment platform,it shows that the stability of system is improved.