Design And Experimental Study Of Strapdown Geomagnetic Vector Measurement System

Geomagnetic field is not only the inherent physical field of the earth,but also an important environmental information source.It has important applications in magnetic anomaly detection,geomagnetic navigation,geophysical resource exploration and so on.Compared with the traditional total geomagnetic field measurement,geomagnetic vector measurement can not only obtain the scalar value of geomagnetic field,but also obtain the geomagnetic field component value,magnetic dip angle,magnetic declination and other information.The strapdown geomagnetic vector measurement system has two characteristics: one is that all parts of the measurement system are fixed in the same frame or carrier,with good integration;the other is that the measurement system can be directly fixed on the moving carrier,without complex electromechanical platform,which is easy to install.However,the accuracy of Strapdown geomagnetic vector measurement is also affected by many factors,such as three-axis magnetic sensor error,ferromagnetic field interference,coordinate transfer alignment.In view of the above problems,this paper studies the error mechanism and comprehensive error model of geomagnetic vector measurement,proposes a comprehensive error correction algorithm based on differential evolution algorithm,carries out the design and research of geomagnetic vector measurement system,develops a set of Strapdown geomagnetic vector measurement system software,and carries out the experimental test.The main work of this paper is as follows:(1)In this paper,the measurement error of magnetic sensor,the magnetic field error of ferromagnetic interference,the misalignment error of sensitive axis between magnetic sensor and attitude sensor are analyzed systematically,and the comprehensive error model and compensation model of geomagnetic vector measurement are obtained.The parameter estimation method of geomagnetic vector comprehensive error model based on differential evolution is proposed,and the algorithm parameters are optimized to ensure the geomagnetic vector measurement.The validity of quantity.(2)The geomagnetic vector measurement system is designed and implemented.According to the general design requirements of the strapdown geomagnetic vector measurement system,the corresponding hardware equipment is selected.Based on the development environment of QT creator,the supporting software of the strapdown geomagnetic vector measurement system is designed and developed in C + +,which realizes the collection,analysis,storage,display and comprehensive error correction of the geomagnetic total amount,three components,attitude angle and other related data.(3)The experiment of Strapdown geomagnetic vector measurement is carried out.Firstly,the error calibration experiment of geomagnetic measurement system is carried out.After calibration,the standard deviation of the north,East and vertical components of the geomagnetic field decreased from 456.3n T to 44.3n T,270.9n T to43.5n T,249.2n T to 39.Tnt,and the total standard deviation decreased from 220.1n T to 27.0n T.Secondly,the experiment of geomagnetic vector measurement is carried out,the measurement system is carried on the car,and the regional geomagnetic vector map is established.