Generation Of Vector Maps For Indoor Positioning And Navigation Based On Bluetooth Beacons

With the development of society,large-scale shopping malls,stadiums,office buildings,hospitals and other buildings are becoming larger and larger,and the number of interior rooms is huge and the layout is sophisticated.It is quite difficult for general visitors to find the target points quickly,and it is urgent to carry out indoors positioning and navigation.The premise and basis is to obtain a scalable vector SVG(Scalable Vector Graphics)format map.Generally,buildings have corresponding CAD(Computer Aided Design)drawings,but they are very different from SVG.Therefore,how to get the required SVG navigation map based on CAD drawings is an urgent problem to be solved.The main process of obtaining the existing map data is: giving a scale map of the building,and then using the map as a reference to manually draw the outline of each building on the base map to obtain the final map.By analyzing the whole process of the current navigation map data acquisition and the representation format of the map data,a near-automated map data acquisition method is proposed.Firstly,the CAD files in the data source and the final navigation SVG files are compared and analyzed.It is found that they are all based on the text form and follow the XML(Extensible Markup Language)writing rules.There is a possibility of conversion between the element objects inside.Then,through further analysis of the CAD alternative format DXF(Drawing Exchange Format)file,the necessary contour information is extracted from the perspective of file semantics,thereby filtering out the remaining interference information that is not useful for navigation(eg,leaving only the outline information of the house and removing the decoration information of the objects inside the house),and then further processing the extracted data,including the midline extraction,near-point connection,and get a preliminary navigation map.Finally,image processing techniques such as opening and closing operations are used to repair the connection vulnerabilities,and contour detection is used to obtain the final SVG map.SVG navigation map conversion is performed through the CAD drawing of a government office building as the data source of the experiment.The results show that for a CAD drawing that satisfies certain drawing styles and constraints,an ideal map can be automatically obtained,and with a small amount of manual participation,a complete navigation map can be obtained,which has useful value.