Research Of Magnetic Localization Technology

The earth we are living on is a huge magnetic object,and it generates the magnetic field which cannot be clearly seen or touched affects objects on it all the time.And the objects on the earth are also affecting the earth.Any magnetic object and ferromagnetic object magnetized by the geomagnetic field,or the conductor cutting the magnetic field to generate eddy currents,etc.,will disturb the geomagnetic field.This phenomenon is called the magnetic anomaly.Magnetic anomaly detection technology is a technology that uses magnetic anomalies to detect and locate magnetic targets.In recent years,it has been widely used in many fields,such as clinical medical diagnosis,robot posture detection,geological resource exploration and so on.As for magnetic anomaly detection technology,magnetic object localization methods based on magnetic gradient tensor are widely studied and used due to a series of advantages.A typical magnetic gradient tensor system usually consists of a sensor array composed of several magnetic sensors.Therefore,factors such as measurement error,sensor sensitivity,and system structure error are considered as the main factors affecting the localization performance of the system and have been widely studied.However,as one of the key factors affecting the localization performance,the influence of the spatial structure of the sensor array on the localization performance has received less attention.At the same time,although the localization methods based on magnetic gradient tensor has a series of advantages,the inherent shortcomings of those methods also form bottlenecks that limit the localization performance.On the basis of the motivation above,this paper did related research around magnetic localization technology based on magnetic gradient tensor.The specific research contents include:(1)In this paper,we provide a spatial design method of sensor array and corresponding optimization strategy to localization based on magnetic tensor gradient to get the optimum design of the sensor array.Based on the results of simulation,magnetic localization systems constructed from the proposed array and the traditional array have been built to carry out localization experiment.The results of experiment have verified the effectiveness of magnetic localization based on the proposed array.(2)Towards accurate magnetic localization,we propose a novel method of fitting the magnetic field intensity and magnetic gradient tensor(MGT)with artificial neural network(ANN)for magnetic object localization,which permits accurate localization of the magnetic object in a certain range.In the simulation,we analyzed and compared the capability of the proposed method and a traditional method based on tensor module gradient.The results show that the average localization error of the proposed method is at least 8 times more accurate than the traditional method in the noisy environment.Besides,a magnetic localization system based on a sensor array was used to carry out a localization experiment and the result has shown the feasibility of the proposed method with the average localization error of 2.15 cm when the magnetic target distance was from 61 to 79 cm.