Research On GPS/INS Tightly Integrated Navigation System

Thispaperaddressesthe problemofGPS/INStightlyintegratednavigationsystem.This topic of research is motivated by the need to develop strategies for improving thesatellite selection efficiency of GPS system in terms of information delivered by INSsystem,andtodesignaGPS/INStightlycoupledsystemprogram.Firstly, this paper provides an overview of the navigation system, including SINS,GPS,andSINS/GPSintegratednavigationsystem.Secondly,thepaperisconcernedwiththesatelliteselectionalgorithmsofGPS,andpays particular attention to the possibility than can improve the satellites selectionefficiency of GPS system, and finds out that one of the improving strategies is thatutilize output information of the INS, and gives a new satellites selection algorithmbased on above ideas. The MATLAB simulation result shows that as long as thesatellites coordinates in WGS-84 coordinates are calculated based on the location andattitude angles information of INS mounted on the fuselage of a airplane, the scope ofvisibleGPS satellites can bedeterminedwithout all of24GPS satellites elevationanglecalculationsineachepoch,theefficiencyofthesatellitesselectionisobviousimproved.Finally, the paper provides a new GPS/INS tightly integrated navigation systemprogram that highlights the INS system to the auxiliary role of the GPS satellitesselection. The program uses closed-loop feedback correction method and fuses datathrough conventional Kalman filter. The paper pays particular attention to comparativeanalysis with GPS/INS loosely coupled navigation system. The MATLAB simulationresults show that the tightly coupled system proposed in the paper has also morenavigationaccuracythanaconventionalloosecoupledsystem.