Study On Geomagnetic Vector Matching Navigation Technology

Geomagnetic navigation uses the characteristics of geomagnetic field for navigation and positioning,and it has the advantages of passive,all-time and all-weather,etc.It has a broad application prospect in the field of military equipment and civil navigation.At present,geomagnetic navigation is mostly based on a single scalar geomagnetic field,the navigation accuracy of which will be greatly affected when the local magnetic environment is complex or when the scalar feature is not obvious.As we know,geomagnetic field is a vector field,which can provide geomagnetic navigation with more matching information compared with the traditional geomagnetic scalar navigation.Thus it will extend the applicable area of geomagnetic navigation,and effectively improve the accuracy and robustness of geomagnetic navigation.In this paper,to solve the shortcomings of traditional geomagnetic scalar navigation,the geomagnetic vector matching navigation technology is studied which is helpful for make better use of geomagnetic vector advantages for navigation and positioning.The main research work and innovation are as follows:(1)The basic principle and key technology of geomagnetic matching navigation are introduced.Two kinds of geomagnetic matching algorithms,MAGCOM algorithm and ICCP algorithm,are theoretical studied and simulated as well.The shortcomings of the two matching algorithm are analyzed in detail,which lays the foundation for the subsequent geomagnetic vector matching research.(2)Aiming at the shortcomings of the traditional scalar algorithm,the geomagnetic vector matching algorithm is studied.A geomagnetic vector matching algorithm based on MAGCOM is proposed,in which an adaptive angle rotation search is added based on the traditional algorithm.And combined with the MSD criterion,the three-component information of the geomagnetic vector is regarded as the correlation criterion,which effectively solves the problem of heading error correction and the single feature quantity prone to mismatching problems;A geomagnetic vector matching algorithm based on ICCP is proposed,in which the three-component difference of the geomagnetic vector is considered as a criterion to find the nearest point on the contour,so the problems,such as easy divergence under large initial error conditions,and the mismatching when the track is parallel or perpendicular to the contour,are solved successfully.The simulation results show that the vector algorithm can solve the problem of the traditional scalar algorithm,and can ensure the matching precision less than a measurement grid.(3)Aiming at the problem that the measurement error of geomagnetic vector in practical application is relatively large,a geomagnetic vector matching algorithm based on total constraint is proposed.The algorithm uses the total magnetic field to constrain the confidence point range to determine the trusted set by three component difference.The trusted path determined according to the reference heading and the each trusted point ranges.Finally,the optimal matching path is selected by the magnetic field correlation.The simulation results show that the geomagnetic vector matching algorithm based on the total constraint can effectively suppress the influence of the geomagnetic vector measurement error,and effectively improve the robustness of geomagnetic navigation.(4)Geomagnetic vector matching navigation experiment is carried out.First of all,vector navigation experiment platform mainly consists of fluxgate sensor,NI myRIO embedded platform and MTi inertial measurement unit.And then,the magnetic field anomalies were generated by placing the magnetic bodies in the experimental area,and the vector geomagnetic maps of the area were measured.After that,the geomagnetic vector matching data with different paths in the region was obtained.Finally,geomagnetism matching is conducted by vector matching algorithm based on the total constraint,vector matching algorithm and total matching algorithm,respectively.The experimental results show that all three can achieve the geomagnetism matching with high accuracy in the significant change of geomagnetic total characteristics.However,when the geomagnetic total feature of the local changes insignificantly,the geomagnetic vector matching algorithm based on the total constraint has the best positioning performance,which can achieve the matching accuracy of about a grid and verify the feasibility of geomagnetic vector matching navigation.