Context-Aware Service Selection Based on the ARToolkit
This thesis deals with extending the AR Toolkit's functionality to
allow not only small stationary setups but wide range tracking
applications as well. Based on a visionary scenario of a mobile user
walking around in a building with an intelligent environment, we split the AR Toolkit's
functionality in several components based on the DWARF (Distributed Wearable Augmented Reality Framework) system. Using a thin mobile client we described a mechanism for a dynamic configuration according to the location context during runtime. Based on the marker detection functionality of the ARToolkit, context changes are triggered (a user leaves a room and enters the next one). This means that the system triggers a context change with different strategies and then gets reconfigured by the environment. We discovered that different trigger strategies are necessary due to different environmental conditions. We discussed the architecture of the location component, evaluate several strategies for a context change and show how environmental conditions can influence the quality of the system.
DWARF Support
These services were implemented to support this functionality in the DWARF environment:
- The VideoGrabber delivers video data using a IEEE1394 firewire connection (libdc1394 library)
- The MarkerDetection searches in video images for certain patterns (ARToolkit library)
- The StateMachine carries the current state (in our case: the current room) and the transitions out of it (doors to other rooms)
- The MarkerConfiguration configures the MarkerDetection with the current marker data and is responsible to start a StateMachine carrying the current room-context
More Documentation
The
VideoGrabber could be used independently from the other services. For understanding the whole functionality of the system please have a look at the basic DWARF mechanisms (like setting predicates, startOnDemand, stopOnNoUse, sharedMem,...). In this work we used the *-functionality implemented by Asa. Please have a look at my thesis and Asa´s paper "Decentralized Coordination of Distributed Interdependent Services" for more information.
Please note that I have changed the name of the
StateMachine into
StateService? and
MarkerConfiguration into
MarkerLoader in my thesis. For further questions please send me an email (
loew@in.tum.de).
--
FelixLoew - 11 Dec 2003
