Transcript Visually Coupled Systems Hardware and the Human Interface

Visually Coupled Systems
Hardware and the Human
Interface
By Dean Kocian and H. Lee Task
Summarized by Geb Thomas
Topics
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HMD optical systems
Helmet/Head tracking systems
System Integration
Applications
Visually Coupled Systems (VCS)
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Integrates the natural visual and motor
skills of an operator into the system he
is controlling
– head- or helmet-mounted visual display
– head tracking and/or eye tracking system
– visual information dependent on above
signals
• physical source
• synthetic source
Simple Magnifier
Compound Microscope
See-Through HMD
Type II has see-through, Type 1 has none.
Miniature Image Source
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Emissive versus non-emissive
Monochrome (narrow bandwidth)
versus color
Magnification
Luminance
– diffuse versus Lambertian emitter
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Resolution
Emissive Displays
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Lasers -- low power, requires very
reliable scanning system, requires high
scan rates to avoid flicker problems
Field-emission displays (FEDs) -Mission of individual electron emitter
guns, combine to light a single pixel.
Prototype 512x512 displays operate at
5kV
Miniature CRTs
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Best choice for many see-through
HMDs.
Disadvantages: long dimensions, highvoltage power supply, weight, hand
assembly required
Advantages -- light conversion
efficiency, resolution (>1M resolution
elements/20 mm.), geometry correction
in scan electronics.
Non-emissive Displays
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Low voltage
Low current
Thermally sensitive
Subtractive color for LCDs.
Tracking Systems
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Head/Helmet-mounted tracker (HMT)
Position and orientation tracker (P&OT)
Head orientation and position (HOP)
Resolution must be known and
repeatable.
Multiple frames of reference (Eye,
Earth, Space, Aircraft)
System Characteristics
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System head coverage and motion box
Static accuracy
Resolution and repeatability
Update rate, throughput rate, and
display refresh rate
– for visual 240 Hz is OK,
– for spatial hearing, 500-1600 may be
required
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# transducers, interference
System Integration
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Ocularity
– Monocular
– Biocular
– Binocular
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Color
Type I or II
Field of View
– Mono, total,
binocular
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Field of regard
Resolution
Luminance
Combiner ratio
– transmittance,
reflectance
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Vignetting
Exit pupil size
Eye relief distance
More Integration Issues
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Interpupillary distance 51-76 mm
Distortion (barrel or pin-cushion)
Update rate
Refresh rate
Eye relief vrs FOV
Resolution vrs FOV
Focus/accommodation