Investigation On The Intelligent Autonomous Navigation And Positioning In Indoor/Underground Environment

With the rapid development of technology,global satellite positioning systems are unable to locate in complex environments such as indoors and underground.Specific local positioning technologies are becoming emerging areas such as indoor navigation in large shopping malls,medical navigation mirror,pipeline inspection,etc.In this context,the magnetic based positioning with the advantages of strong penetrability,intensified anti-interference and unnecessary of direct eyesight is one of the essential research areas in recent years.First,this article studies the theoretical basis of magnetic positioning.The Ampere force law,right-hand screw rule and Biot-Savart law of electromagnetism are researched and verified.The constant magnetic field model and time-harmonic magnetic field model of a single beacon are introduced and deduced.The complex vector expression of the time-harmonic magnetic field and the corresponding Maxwell equations are derived.The propagation law of low-frequency time-harmonic magnetic field is studied,which can be used to determine the effective range of magnetic field positioning in different application scenarios.To prepare for the application,the method of low-frequency time-harmonic magnetic field signal extraction is studied.Finally,the safety of electromagnetic exposure has been studied.In the third chapter,a long straight solenoid is selected as the magnetic beacon to reduce the limitation of the sensor attitude in the magnetic field positioning and reduce the computational burden.The magnetic beacon positioning method based on the analytical method has been studied.First,the composition of the system is studied,the positioning algorithm is derived,and the correctness of the algorithm is verified by mathematical simulation.Then the experimental platform of the analytical method is built,and preliminary work such as hardware system construction,software coding and the signal acquisition is completed,which lays the foundation for the following research.In the fourth chapter,the intelligent search algorithm into the positioning system of this article is introduced to solve the problems existing in the above-mentioned analytical method positioning system,such as the high accuracy of beacon installation and the need to distinguish quadrants.This method does not require strict installation of the beacon and only needs to determine the magnetic field information in the space after installation.The use of small beacons achieves the effect of reducing power consumption.The magnetic field positioning method based on genetic algorithm is studied,and the simulation results verify the correctness of the algorithm and the positioning effect is good.In order to improve the real-time performance of the system,the positioning method based on the quantum genetic algorithm is studied.The simulation results show that the running time of the positioning system based on the quantum genetic algorithm is reduced by an order of magnitude.In the fifth chapter,the two-dimensional positioning method based on the fusion of magnetic field and inertial navigation information has been investigated to solve the problem of low magnetic field positioning frequency and discontinuous trajectory when tracking high-speed moving objects.First,the positioning algorithm based on the Kalman filter method is studied.Due to the accumulated error of the inertial navigation system,long-term reliable positioning cannot be performed.The data of the inertial system and the magnetic field are fused,and a better result than the two independent positioning is obtained.In order to improve the robustness of the system and expand the application scenarios,a data fusion positioning algorithm based on H? filtering method is studied.The simulation results show that the algorithm can still accurately track the target under the condition of strong colored noise.In the last chapter,the three-dimensional space positioning method based on the fusion of single magnetic beacon and inertial navigation information is studied in order to broaden the application field of low-frequency magnetic field positioning technology.First,the polar coordinate equation of the magnetic field generated by the singlemagnetic beacon is given,and the simulation analysis is carried out.The specific composition of the system and the principle of each part are given,and the positioning process of the three-dimensional positioning algorithm is analyzed and deduced,which provides a reference for the research of the three-dimensional positioning technology based on the magnetic field.