Comparison Research And Improvement Of Geomagnetic Aided Navigation Matching Algorithms

Inertial navigation systems can only maintain high accuracy in a short period of time,and are not suitable for long-term navigation.Therefore,it is often used in combination with other navigation technologies to maintain its accuracy.As one of the integrated navigation technologies,geomagnetic assisted navigation has the characteristics of non-radiation,full area,low cost,and rich matching features,and has been developed rapidly.Through simulation experiments,this paper compares the advantages and disadvantages of the matching algorithm around the matching algorithm of geomagnetic assisted navigation,analyzes the influence of the geomagnetic field distribution on the matching algorithm,and improves some of the algorithms,as follows:(1)The geomagnetic matching algorithm is the core of the geomagnetic assisted navigation technology.This article studies the correlation sequence algorithm represented by MAGCOM and ICCP,and the recursive filtering algorithm represented by SIMAN,and analyzes the advantages and disadvantages of the above algorithms from the principles and experimental results.Aiming at the situation that the MAGCOM algorithm cannot adapt to the large heading deviation,an improved MAGCOM algorithm is proposed,which adds a rotation transformation to improve the positioning accuracy through iterative methods.Through simulation experiments,in the same matching area,the average point error of the improved MAGCOM algorithm has been reduced by about 50%.(2)According to the distribution characteristics of the geomagnetic field in the matching area,analyze the influence of the matching results of the correlation sequence algorithm,and obtain the relationship between the geomagnetic contour direction and the inertial navigation position error: when the contour is approximately parallel In the case of inertial navigation position error,the correlation sequence algorithm has a large matching error;when the contour approximates the vertical inertial navigation position error,the correlation sequence algorithm can effectively reduce this error.(3)The traditional matching navigation algorithm needs to use two-dimensional geomagnetic data at a certain height.When the height of the underwater vehicle changes,the use of the traditional matching algorithm will cause matching errors.Aiming at this problem,a three-dimensional ICCP algorithm is proposed,which combines the potential field continuation and the ICCP algorithm,and uses the potential field continuation method to extend the geomagnetic reference map to the same height as the aircraft,and use it as the ICCP algorithm The geomagnetic reference map needed to find the nearest contour point.After simulation experiments,compared with the traditional ICCP matching algorithm,the accuracy of the three-dimensional ICCP algorithm is increased by 12.89%,21.54%,28.50%,34.64% when the height changes are 50 m,100m,150 m,200m.Therefore,the algorithm effectively improve the matching accuracy of the aircraft when the altitude changes.