| In recent years,integrated navigation system has developed rapidly,in which SINS/GPS integrated mode is the most widely used.However,GPS is vulnerable to interference and can not ensure the reliability of the system.With the development of geomagnetic navigation theory and sensor technology,geomagnetic navigation has become a hot research topic at home and abroad because of its advantages of all-weather,all-weather,all region,autonomy and concealment.The use of geomagnetic navigation assisted inertial navigation system for positioning can make up for the lack of position error accumulation with time,and meet the navigation requirements of high precision for a long time.Based on the existing algorithms,aiming at the key technologies of geomagnetic aided navigation system,this paper further studies the links of magnetic data noise reduction,geomagnetic map interpolation,geomagnetic matching and positioning.The main works are as follows:Firstly,aiming at the problem that magnetic sensors are vulnerable to external interference when collecting geomagnetic field data,a geomagnetic compensation algorithm based on M-estimation based on Tukey cost function is proposed.In the process of ellipsoid fitting,M estimation algorithm is introduced,the weight is set for each acquisition point according to the residual,and a new correction matrix is calculated to reduce the influence of abnormal points.Compared with the traditional ellipsoid fitting compensation algorithm based on least square method,it has better robustness and better compensation effect.Secondly,aiming at the problem of geomagnetic map interpolation,a variety of interpolation techniques are analyzed and compared,and the optimization method of Kriging interpolation model parameters is improved.By introducing simulated annealing particle swarm optimization algorithm to find the optimal parameters of the model,the global search ability is enhanced,and the optimization efficiency of the algorithm is improved.The simulation results show that the overall accuracy and deviation of the estimated value are better than the traditional methods,and can better meet the needs of the establishment of the reference geomagnetic map.Thirdly,aiming at the problem that the traditional algorithm in geomagnetic matching location is sensitive to heading angle error and initial position error,combined with geomagnetic affine model,a matching algorithm based on improved particle swarm optimization genetic algorithm is developed.The introduction of genetic algorithm avoids the particle falling into local optimization.In addition,it has faster convergence performance by constraining the initial position of the particle.Simulation results show the effectiveness and anti-noise of the algorithm.Fourthly,A geomagnetic data acquisition platform based on ARM chip is designed.Based on the structure of "sensor + integrated processing unit + host computer",the overall hardware block diagram design and core chip selection are completed.According to the working principle of analog-to-digital conversion chip and the requirements of signal isolation,the circuit schematic diagram and PCB board of geomagnetic data acquisition platform are designed.The SPI magnetic survey data communication module,data filtering module and 485 host computer communication module are further designed to complete the construction of geomagnetic data acquisition platform.Finally,aiming at the geomagnetic aided navigation technology studied,a hardware in the loop simulation experiment is designed.On the developed data acquisition platform,the three-axis magnetic sensor ms3a-01a-w and high-precision reference element span-cpt are used to collect geomagnetic data and position information,and the magnetic sensor compensation algorithm,geomagnetic map difference technology and matching algorithm proposed in this paper are tested through off-line experiments.The experimental results show that the proposed method has advantages and the performance of geomagnetic aided navigation system is improved. |
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