Fundamentals of Ubiquitous Tracking for

Augmented RealityVienna University of TechnologyVienna University of Technology

Joe Newman, Thomas Pintaric, Dieter SchmalstiegJoe Newman, Thomas Pintaric, Dieter Schmalstieg

Technische Universität MünchenTechnische Universität MünchenMartin Wagner, Asa MacWilliams, Martin Bauer, Gudrun KlinkerMartin Wagner, Asa MacWilliams, Martin Bauer, Gudrun Klinker

For more information email: jfn@ims.tuwien.ac.at

Joseph Newman December 19th - Studierstube Day III, 2003

Augmented Reality (AR)

• Rich and meaningful AR experienceRich and meaningful AR experience• Wearable computingWearable computing

• Graphics rendering,display technologiesGraphics rendering,display technologies• Spatial model of worldSpatial model of world

• Up-to-date & coherentUp-to-date & coherent• Requires trackers and special sensorsRequires trackers and special sensors

• Parallels with UbiComp, but crucial differenceParallels with UbiComp, but crucial difference• Motivation to look at a global approach to Motivation to look at a global approach to

unifying different tracking systemsunifying different tracking systems

Joseph Newman December 19th - Studierstube Day III, 2003

Ubiquitous Tracking

• Graph-based modelGraph-based model• Express spatial inter-relationshipsExpress spatial inter-relationships• Dynamically extendible tracker Dynamically extendible tracker

networks of trackers networks of trackers • High-precision, low latency requirementsHigh-precision, low latency requirements• Framework extensible:Framework extensible:

• New trackers, filtering schemes, New trackers, filtering schemes, optimisation criteriaoptimisation criteria

Joseph Newman December 19th - Studierstube Day III, 2003

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World Model

Joseph Newman December 19th - Studierstube Day III, 2003

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Measured Relationships

Joseph Newman December 19th - Studierstube Day III, 2003

Inferred Relationships

Joseph Newman December 19th - Studierstube Day III, 2003

Fusion + other filtering

““The use of multiple location systems simultaneously to The use of multiple location systems simultaneously to form hierarchical and overlapping levels of sensing to form hierarchical and overlapping levels of sensing to increase accuracy beyond what is possible using any increase accuracy beyond what is possible using any individual system”, Hightowerindividual system”, Hightower

• New inference results in new edge in G(New inference results in new edge in G(• Model other filtering schemesModel other filtering schemes

• Environmental knowledgeEnvironmental knowledge• Voronoi graphsVoronoi graphs

• Bayesian, particle filters, etc….Bayesian, particle filters, etc….

Joseph Newman December 19th - Studierstube Day III, 2003

Relationship Modelling• RepresentationRepresentation

• Not just homogeneous matricesNot just homogeneous matrices• Pixel locations (x,y), 3D positions (x,y,z)Pixel locations (x,y), 3D positions (x,y,z)• Accelerations and velocitiesAccelerations and velocities

• AttributesAttributes• Latency, update frequency, confidence value, pose Latency, update frequency, confidence value, pose

accuracy, Monetary cost, time-to-liveaccuracy, Monetary cost, time-to-live• Difficult to obtain from proprietary devicesDifficult to obtain from proprietary devices• Slowly varying (compared to tracking data)Slowly varying (compared to tracking data)

Joseph Newman December 19th - Studierstube Day III, 2003

Joseph Newman December 19th - Studierstube Day III, 2003

Optical shared tracking

Marker K need only be visible to a single cameraMarker K need only be visible to a single camera

Including other sensors extends range of possible Including other sensors extends range of possible inferencesinferences

Joseph Newman December 19th - Studierstube Day III, 2003

Joseph Newman December 19th - Studierstube Day III, 2003

Future Work

• SimulationSimulation• ImplementationImplementation

• Studierstube/OpenTrackerStudierstube/OpenTracker• DWARF componentsDWARF components

• Auto-calibrationAuto-calibration• Model small amounts of uncertaintyModel small amounts of uncertainty• Adaptive modelAdaptive model

• EvaluationEvaluation

Joseph Newman December 19th - Studierstube Day III, 2003

Conclusion• Theoretical framework describing Theoretical framework describing

tracking setupstracking setups• Inter-relationships modelled in a graphInter-relationships modelled in a graph

• State spaces, attributes, error functionsState spaces, attributes, error functions• ExtendibleExtendible

• Maps to implementation of UbiTrack Maps to implementation of UbiTrack concepts (work in progress!)concepts (work in progress!)

• Partial standardisation of tracker setupsPartial standardisation of tracker setups• Formal approach towards ubiquity of ARFormal approach towards ubiquity of AR