mobile navigation with svg christian schmitt svg open 2005

Download Mobile Navigation With SVG Christian Schmitt SVG Open 2005

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  • Mobile Navigation With SVGChristian SchmittSVG Open 2005

  • ContentsIntroductionContentsIndoor positioning systemsPathfinding + Map generatorMap viewer + navigationDemoconclusion

  • Indoor Positioning Technologies OverviewInfrared (IR)

    Wireless LAN (WLAN)

    Ultra-wide band (UWB)

    Hybrid solution

  • InfraredPrinciple/FeaturesIR beacons sending a specific code. Directed connection. Range: 80-300 cmAccuracy: see range

    AdvantagesUniversalInexpensiveBasic technology

    DisadvantagesLine of sight requiredDoes not scale very wellMaintenance costs

  • WLANPrinciple/FeaturesFingerprinting based on signal strength measurementsAccuracy: 3-7 meters

    ProsUse of existing WLAN infrastructureMost PDAs have WiFi. WiFi tagsEasy to setupLarge area covered

    ContrasHigh power consumption of WLAN cardPoor update rateCalibration step

  • Ultra Wide BandFeaturesNo multipath distortionTime Difference of Arrival, Angle of ArrivalAccuracy: 15cm

    ProsAccuracyGood update rate

    ContrasSpecial hardwareComplex Setup

  • Our hybrid solutionWLAN from Ekahau IncCoverage: whole floor Accuracy: 3 meters

    UWB from Ubisense Coverage: single roomAccuracy: 20 cm

    IR from guideID and EyeledCoverage: few emitters in front of pictures

  • PathfindingIntroductionContentsIndoor positioning systemsPathfinding + map creationMap viewer + navigationDemoconclusion

  • SVG Map generationProblem: the same SVG map will not render on all platforms

    Solution:create a common semantic description of the map together with transformation rules specific to each platform

    ImplementationDTD suitable for room plansUser Interface to define a new mapXSLT transformation to output SVGA XSLT file for each target platform

  • The A* algorithm implementation A* algorithmIs a graph search algorithm that finds a shortest path from a given initial node to a given goal nodeUses an heuristic to direct the searchCost function is the distance between two nodes

    ImplementationRoute computation on client (Windows Mobile 2003)Implemented using STL libraryGraph stored as text file

  • Map viewerIntroductionContentsIndoor positioning systemsPathfinding + helper toolsMap viewer + navigationDemoconclusion

  • Viewer functionalitiesZoom in/out, panning

    Display of the current position

    Selection of a destination and display of the optimal route

    Animations of objects

    Support for information browsing on the map

  • On the search for perfectionFirst step: Personal Java application rendering raster bitmap

    Drawbacks:Raster bitmap: not scalable, high footprintJava: weak user interface, waste of system resources, no access to hardware resources

    Next step: Native C++ application rendering SVG.

    Which SVG viewer to use ?

  • Which SVG viewer?Only two native SVG viewers available for Windows Mobile-based PDAs: eSVG and BitFlash

    eSVGeSVG 1.6 license purchased in Mai 2003Performance issuesLatest version with .NET support

    BitFlashBitFlash SDK license purchased in Spring 2004Fast rendering and good interaction capabilities

  • Using BitFlash SDKUsage guidelinesCreate player instance, load documentCommunication with the player via commands and callback functions, DOM APIOnly one thread should access the player at the same time

    ExampleZooming in: BFZoomEvent zoomData;zoomData.fpFactor = 0x7FFF;//0xcccc; // 1.5 in 16.16 fixed point zoomData.iCenterX = (BF_INT16)point.x;zoomData.iCenterY = (BF_INT16)point.y;int dwWait=WaitForSingleObject(hSVGPlayerSemaphore,INFINITE);CheckStatus(BFprocessCommand( pPlayer, BF_COMMAND_VIEW_ZOOM, &zoomData ));CheckStatus(BFprocessCommand( pPlayer, BF_COMMAND_VIEW_REDRAW, 0 ));ReleaseSemaphore(hSVGPlayerSemaphore,1,NULL);

  • Integration of positioning technologiesEkahau/UbisenseServer: Middleware server connecting to Ekahau and Ubisense Server, keeping position information up-to-date and delivering position data to clientsClient: Location Thread connects to server, parses messages and refreshes buddy position on mapIRIR thread is listening on IR port (serial)IR code found => trigger animationIssuesRefresh rate (only Orinoco cards provide good results) Integration

  • DemoDemo

  • ConclusionPositioningAppropriate combination of positioning systems needed to achieve best tradeoff between quality of service and costIndoor navigation is still a very challenging research topic

    SVGSVG maps are perfect for mobile navigationRendering of SVG maps no longer too slow

    Future workBetter navigation : audio output and personalized routes Seemless integration of positioning systemsTests on Symbian and .NET

  • Thank you !

    Mobile guide for windows mobile-based PDAsWithout a reliable existing positioning system, navigation is not possible. Therefore a careful investigation about the existing technologies, their advantages and limitations, is needed.There are numerous technologies available for user tracking.

    Proximity-based technologies : IR, RFID

    Make a new picture with a hand to compare sizeTransition: so IR is good for a limited area, e.g when other positioning techniques are not available or not adequate. RF-based technologies enable to cover a wider areaCheap: can use existing wlan infrastructure. Accuracy of 5 meters because multipath decreases accuracyThe wlan cards were not designed for positioning but for bandwithStandard drivers are not fast enough for signal strength readingCalibration step needs to be repeated periodically

    Special hardware -> higher costsComplex setup due to synchronization between sensors, area covered is smallerShow map of FIT floor, with combination of WLAN, Ultrawide band and IR (see denis)Purpose : be able to generate multiple maps for different kind of platforms/svg viewers, especially for room plans.Most implementations are based on a square structure rather than a node structureThe functionalities the viewer should provideWith a native application it is possible to have greater controlLook at the picture: doesnt look really impressive !

    Is it correct ? Let me know if you know about another one ?Synchronization via semaphores and stop eventsWithout a reliable existing positioning system, navigation is not possible. Therefore a careful investigation about the existing technologies, their advantages and limitations, is needed.There are numerous technologies available for user tracking.There is no standard like GPS. Maybe a new technology aimed at positioning is needed. Focus is on bandwidth, but position info is very valuble.

    Bitboys hardware acceleration