Vortrags-Vorspann

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Mobile Navigation With SVG
SVG Open 2005
Christian Schmitt
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Contents

• Introduction
• Contents
• Indoor positioning systems
• Pathfinding Map generator
• Map viewer navigation
• Demo
• conclusion

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Indoor Positioning Technologies Overview

• Infrared (IR)
• Wireless LAN (WLAN)
• Ultra-wide band (UWB)
• Hybrid solution

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Infrared

• Principle/Features
• IR beacons sending a specific code.
• Directed connection.
• Range 80-300 cm
• Accuracy see range
• Advantages
• Universal
• Inexpensive
• Basic technology
• Disadvantages
• Line of sight required
• Does not scale very well
• Maintenance costs

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WLAN

• Principle/Features
• Fingerprinting based on signal strength
  measurements
• Accuracy 3-7 meters
• Pros
• Use of existing WLAN infrastructure
• Most PDAs have WiFi. WiFi tags
• Easy to setup
• Large area covered
• Contras
• High power consumption of WLAN card
• Poor update rate
• Calibration step

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Ultra Wide Band

• Features
• No multipath distortion
• Time Difference of Arrival, Angle of Arrival
• Accuracy 15cm
• Pros
• Accuracy
• Good update rate
• Contras
• Special hardware
• Complex Setup

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Our hybrid solution

• WLAN from Ekahau Inc
• Coverage whole floor
• Accuracy 3 meters
• UWB from Ubisense
• Coverage single room
• Accuracy 20 cm
• IR from guideID and Eyeled
• Coverage few emitters in front of pictures

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Pathfinding

• Introduction
• Contents
• Indoor positioning systems
• Pathfinding map creation
• Map viewer navigation
• Demo
• conclusion

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SVG Map generation

• Problem
• 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
• Implementation
• DTD suitable for room plans
• User Interface to define a new map
• XSLT transformation to output SVG
• A XSLT file for each target platform

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The A algorithm implementation

• A algorithm
• Is a graph search algorithm that finds a shortest
  path from a given initial node to a given goal
  node
• Uses an heuristic to direct the search
• Cost function is the distance between two nodes
• Implementation
• Route computation on client (Windows Mobile 2003)
• Implemented using STL library
• Graph stored as text file

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Map viewer

• Introduction
• Contents
• Indoor positioning systems
• Pathfinding helper tools
• Map viewer navigation
• Demo
• conclusion

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Viewer functionalities

• Zoom 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

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On the search for perfection

• First step
• Personal Java application rendering raster bitmap
• Drawbacks
• Raster bitmap not scalable, high footprint
• Java weak user interface, waste of system
  resources, no access to hardware resources
• Next step
• Native C application rendering SVG.
• Which SVG viewer to use ?

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Which SVG viewer?

• Only two native SVG viewers available for Windows
  Mobile-based PDAs
• eSVG and BitFlash
• eSVG
• eSVG 1.6 license purchased in Mai 2003
• Performance issues
• Latest version with .NET support
• BitFlash
• BitFlash SDK license purchased in Spring 2004
• Fast rendering and good interaction capabilities

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Using BitFlash SDK

• Usage guidelines
• Create player instance, load document
• Communication with the player via commands and
  callback functions, DOM API
• Only one thread should access the player at the
  same time
• Example
• Zooming 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 dwWaitWaitForSingleObject(hSVGPlayerSemaphore
  ,INFINITE)
• CheckStatus(BFprocessCommand( pPlayer,
  BF_COMMAND_VIEW_ZOOM, zoomData ))
• CheckStatus(BFprocessCommand( pPlayer,
  BF_COMMAND_VIEW_REDRAW, 0 ))
• ReleaseSemaphore(hSVGPlayerSemaphore,1,NULL)

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Integration of positioning technologies

• Ekahau/Ubisense
• Server Middleware server connecting to Ekahau
  and Ubisense Server, keeping position information
  up-to-date and delivering position data to
  clients
• Client Location Thread connects to server,
  parses messages and refreshes buddy position on
  map
• IR
• IR thread is listening on IR port (serial)
• IR code found gt trigger animation
• Issues
• Refresh rate (only Orinoco cards provide good
  results)
• Integration

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Demo
Demo
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Conclusion

• Positioning
• Appropriate combination of positioning systems
  needed to achieve best tradeoff between quality
  of service and cost
• Indoor navigation is still a very challenging
  research topic
• SVG
• SVG maps are perfect for mobile navigation
• Rendering of SVG maps no longer too slow
• Future work
• Better navigation audio output and personalized
  routes
• Seemless integration of positioning systems
• Tests on Symbian and .NET

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Thank you !