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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 Management	Management of the flow of information between the application programme and the host VR system	Conventional programming	None	H
	Management of data interaction between shared virtual environments	Point to point links	None expected - limited demonstration	H
	Links cognitive aids in A1 to other VR modules	Networks	Effective protocols - especially for large user groups	H
A3. Control-display Coordination	Consolidating input from head, hand, eye, voice input devices	High performance CPUs	Interface standards	H
A3. Control-display Coordination	Coordinating visual, auditory, tactile and kinaesthetic feedback	Multi processor architectures Software development tools		H H
A4. Data storage and Recording	3D object databases	Powerful modelling software Software tools	None - well developed	H
A4. Data storage and Recording	Recording of user interaction for later analysis
A5. Image Generation	Production of formatting instructions for virtual displays	High performance graphic computers to generate video signals	Synchronisation between left and right hand channels	H
	Stereo image generation	Stereo image production	Distortion correction algorithms	H
	Stereo image generation	Multi-channel systems	Synchronisation btween channels	H
A6. Tactile Stimulus Generation	Provision of synthetic tactile cue signals	Piezo electric vibrator stimulus	Resolution, accuracy	H
A7. Kinaesthetic Stimulus	Provision of synthetic force feedback signals	Force reflecting actuators Force reflecting joysticks	Safety critical software and hardware, bio-mechanical modelling	M
A8. Auditory Signal Generation	Provision 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
A8. Auditory Signal Generation	Utilisation: Augmented visual environment Improved situation awareness Attention getting Warning information			H H M M
A9. Speech Processing	Speech recognition for hands free function selection	Template 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 Controller	Direct manipulation in 3D environment	Fibre optic flexion sensors Strain gauge sensors	Accuracy, non intuitive	M M
A12. Head Sensor Processing	Used 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 Processing	Eye 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 Processing	Work load evaluation	Heart beat Blood pressure	Link to workload not fully understood	M

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 Feedback	Confirmation of key press Object interaction Vibrotactile stimulation	Mechanical actuation, shape Piezo-electric effect	None	H M
Kinaesthetic Feedback	Collision detection, force coupling	Mechanical actuation Force reflecting joysticks Robot arms/manipulations	Resolution Safety, practicality	M
B3. Audio Production	Generation of audio feedback signals for: Key clicks Synthetic speech and localisation cues	Earphones Loudspeakers	None	H H
B4. Speech Transduction	Speech input for speech recognition system	Microphone	None	H
B5. Hand Operated Controls	2D Joystick Mouse 3D Joystick	Shaft encoders Tracking system refer to B6	None	H
B6. Head Sensing	Visually 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 Sensing	Data source for A14	Sense: - Heart rate - Blood pressure - Pupil diameter - Body motion --- Head motion --- Hand motion	None	M
B9. External Environment Viewing	Integration 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 correction	Spectacles Contact lenses Corneal operation	Can lead to problems with HMD design	N/A

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