The Acquisition System Design Of Reference Map Based On Magnetic Field Data

Human society has developed rapidly,the population of China's urban will be more and more in the future.At present,our country is in the rapid development stage of urbanization,some areas appear "urban disease" problem.In order to solve the problems encountered in the development of China's urban,and to achieve sustainable urban development fundamentally,the development of smart city has become an irreversible historical task of urban development.The development of smart city must consider the spatial location information,in the outdoor,due to the emergence of global positioning system(GPS),the outdoor space positioning technology is developed,its characteristics such as convenient,accurate,efficient and so on directly affect people's life.Meanwhile,GPS positioning technology also has its limitations,within the scope of the city,due to the influence of the multipath effect and GPS signal shielding,we gain few interior space information,it can not combine indoor and outdoor space information perfectly and hind the development process of smart city.In the interior environment,an efficient,accurate and convenient navigation and positioning technology is needed to obtain the location information of the indoor space.Therefore,many experts and scholars engaged in the study of interior positioning and navigation.This paper first discusses the characteristics of interior magnetic field,and through a lot of experiments and related knowledge focuses on the analysis of interior geomagnetic variation with time and space geomagnetic disturbance factors on indoor geomagnetic reference map generation influence.This experiment found that the magnetic field change with time is not obvious,can be used as the basis for fingerprint identification data for indoor positioning.Also found that the different space position in the magnetic field on the direction and magnitude are quite different.The interior geomagnetic interference elements are divided into static and dynamic magnetic interference element,the experiment shows that the ferromagnetic materials and electronic devices have a great influence on the magnetic field.At the same time,the magnetic field around the static interference elements is obviously different from the external magnetic field,so the static interference elements can be used as the identification of geomagnetic indoor positioning.Also,the influence of dynamic interference element on the geomagnetic field is not negligible,and its mobility has a negative impact on the generation of interior geomagnetic reference map.Therefore,in the process of collecting the geomagnetic reference map data,should try to avoid the dynamic interference elements.In this paper,first of all,through a series of experiments to prove the feasibility of the geomagnetic field information as a basis for interior positioning.Secondly,by analyzing the interior geomagnetic interference element of different indoor scene,it is concluded that the relationship between the magnetic field and interference elements.In this paper,using multiple HMC5983 magnetic sensor on a mobile platform to gather l arge numbers of indoor geomagnetic reference map,which can achieve the high efficient,Acc uracy and convenience of date acquisition,researched and designed interior geomagnetic reference map data collection mobile platform,on which,equipped with many sensors,such as inertial navigation sensors,wheel encoders,magnetic sensors,infrared sensors,ultrasonic se nsors and Bluetooth sensor,etc.,which can achieve the functions of date acquisition,wireless transmission and others.Using the specific data format for data collection,calculate the track data of the inertial navigation sensor and wheel encoder trough the serial debugging tools,and the interior space position of the mobile platform is obtained.The two-dimensional plane coordinate and its corresponding three-dimensional geomagnetic data are stored in a fixed format.Using the Kriging method to difference of the geomagnetic map data,which generates the required interval size of grid geomagnetic map,then save the geomagnetic reference map in the database.