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Exploiting Virtual Reality Techniques in Education and Training: Technological Issues

17. Appendix H Functional Characterisation Tables

Functional Category Potential Use Likely Technique Limitations Value
A Information Processing
A1 . Cognitive Agents User support in:
On line help Conventional computing - deterministic solutions
IKBS techniques
AI techniques

User requested
Not fully developed
Non real time
Validation difficult

H
H
M
Navigational aids in fly through modeI Conventional computing None H
A2. Data ManagementManagement of the flow of information between the application programme and the host VR systemConventional programmingNoneH
Management of data interaction between shared virtual environmentsPoint to point linksNone expected - limited demonstrationH
Links cognitive aids in A1 to other VR modulesNetworksEffective protocols - especially for large user groups H
A3. Control-display Coordination Consolidating input from head, hand, eye, voice input devicesHigh performance CPUsInterface standardsH
Coordinating visual, auditory, tactile and kinaesthetic feedbackMulti processor architectures
Software development tools
H
H
A4. Data storage and Recording3D object databasesPowerful modelling software
Software tools
None - well developed H
Recording of user interaction for later analysis
A5. Image GenerationProduction of formatting instructions for virtual displaysHigh performance graphic computers to generate video signalsSynchronisation between left and right hand channelsH
Stereo image generationStereo image productionDistortion correction algorithmsH
Multi-channel systemsSynchronisation btween channelsH
A6. Tactile Stimulus GenerationProvision of synthetic tactile cue signalsPiezo electric vibrator stimulus Resolution, accuracy H
A7. Kinaesthetic StimulusProvision of synthetic force feedback signalsForce reflecting actuators
Force reflecting joysticks
Safety critical software and hardware, bio-mechanical modellingM
A8. Auditory Signal GenerationProvision of audio signals:
Sound effects
Stereophonic
3D localisation
Speech synthesis
Computer derived digital audio generation
Digitised audio

Computer generated speech generation


3D localisers are user dependant and not very well developed
Knowledge of human auditory processing needs more research

H
H
H
H
Utilisation:
Augmented visual environment
Improved situation awareness
Attention getting
Warning information

H
H
M
M
A9. Speech ProcessingSpeech recognition for hands free function selectionTemplate based recogniser system
Isolated word capability
Connected speech capability
Continuous connected speech capability
User depedendancy
Limited use non intuitive
Technology limited
Expensive technology immature
L
L
M
H
A10. Switch Processing Integration of:
Keyboards
Multi-function control panels
Multi-function buttons on hand controllers
Conventional keyboards
Touch screens, multi-function keyboards
None
Ease of use
None

H
H
H
A11. Virtual Hand ControllerDirect manipulation in 3D environmentFibre optic flexion sensors
Strain gauge sensors
Accuracy, non intuitiveM
M
A12. Head Sensor ProcessingUsed to generate head line of sight data for:
Visually coupled displays
Motion parallax display function
Area of interest display
High speed DSP technology
Dedicated EM tracker system
Image processing
Accuracy
Phase lag and general response
Susceptability to environmental effects

H
H
M
A13. Eye Sensor ProcessingEye control to:
Hands free control designation
Function activation
IR image analysis
Corneal reflex system
Accuracy
Must determine head - eye sensor slip
H
A14. Physiological Sensor ProcessingWork load evaluationHeart beat
Blood pressure
Link to workload not fully understoodM

Functional Category Potential Use Likely Technique Limitations Value
B Direct Man-Machine Interface
B1. Visual Information Display
Desk top displays

Large screen projection displays

Head coupled displays

Head mounted displays



BOOM displays
High resolution non immersive display

High resolution partial immersive display

360 field of regard

Full immersion



Full immersion high resolution, low lag display
CRT
LCD

Large screen CRT
LCD

CRT
LCD colour shutter
Mirror matrix display

CRT
LCD colour shutter
Mirror matrix display



No correction for curved screens

Single user mode

Low - medium resolution
Noticable lag


Medium - high resolution
Frame sequential - non standard video format
H
H

H

H

H


H
H
B2. Tactile FeedbackConfirmation of key press

Object interaction
Vibrotactile stimulation
Mechanical actuation, shape


Piezo-electric effect
None



H


M
Kinaesthetic FeedbackCollision detection, force couplingMechanical actuation
Force reflecting joysticks
Robot arms/manipulations
Resolution
Safety, practicality
M
B3. Audio ProductionGeneration of audio feedback signals for:
Key clicks
Synthetic speech and localisation cues

Earphones
Loudspeakers
None

H
H
B4. Speech TransductionSpeech input for speech recognition systemMicrophoneNoneH
B5. Hand Operated Controls2D Joystick
Mouse
3D Joystick
Shaft encoders

Tracking system refer to B6
None


H


B6. Head SensingVisually coupled system

Area of interest displays

Motion parallax displays
Electro-mechanical
Electro-magnetic
Acoustic
Optical
Image processing
Fibre optic gyro
Range of movement
Lags, interference,
Lags, interference
External lighting
Immature technology

M
H
M
H

B7. Eye Sensing Corneal reflection
Image processing
Biosignal analysis
Resolution
Stability
M
B8. Physiological SensingData source for A14Sense:
- Heart rate
- Blood pressure
- Pupil diameter
- Body motion
--- Head motion
--- Hand motion
None M
B9. External Environment ViewingIntegration of real and virtual environments
Overlay of virtual display information onto real environment
Augmentation of real environment

Optical or electronic mixing
Chroma key techniques
Registration between real and virtual environments

H

B10. Visual defect correction Eye sight correctionSpectacles
Contact lenses
Corneal operation
Can lead to problems with HMD designN/A

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