Displays

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Functions of Dynamic Visual Displays

• Continuous System Control• steering (vehicle control)• tracking

• state variable target value

• System Status Monitoring• quantitative (state information)

• levels (quantities)• rates

• qualitative (status)

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Functions of Dynamic Visual Displays (2)

• Briefing• mission plans• procedures

• Search and Identification• surveillance

• Decision Making• alternative identification, selection• planning• diagnosis• extrapolation

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Visual Display Technology

• Mechanical (often electromechanical)• fixed/moving pointer, moving/fixed scale• counters (e.g., odometers)• flags

• Electronic• lights (incandescent, nixie tubes)• light emitting diodes (LEDs)• liquid crystal displays (LCDs)• other flatpanel displays• cathode ray tubes (CRTs)

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Visual Display Technology (2)

• Optical Projection• projectors

• front projection• back projection

• head-up displays (HUDs)• head mounted displays (HMDs)

Visual Displays

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OIL

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Annunciators

Counter

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General Display Principles

• Color

• Coding

• Approximation

• Integration

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Color

• Advantages• aesthetic appeal (user-preferred)• opportunity for color coding• superior performance (in some cases)

• Disadvantages• technological limitation, cost• non-superior performance (in other

cases)

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Coding

• Color• < 9 discriminable colors (absolute

discrimination)• < ? (relative discrimination)

• Shape• alphanumeric: < 82

(A-Z, a-z, 0-9, <, (, +, &, …)• geometric: < 15• pictorial: < ?

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Coding (cont’)

Magnitude < 7 (± 2)• area

• line length

• number of primitives

• luminance

• stereoscopic depth

• inclination

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Approximation

• Definition• Get attention with one display• Present detailed info with another

• Example• Red oil pressure annunciator near LOS• Oil pressure gauge elsewhere

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13 Principles of Display Design (Wickens, Gordon, & Liu)

• Perceptual Principles

• Mental Model Principles

• Principles Based on Attention

• Memory Principles

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Perceptual Principles

1. Avoid absolute judgments• absolute vs. relative judgment

2. Top-down processing• people observe what they expect to

observe

3. Redundancy gain• alternative stimulus attributes

4. Discriminability• similarity causes confusion

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Mental Model Principles

5. Pictorial realism• looks like what it represents

6. Principle of the moving part• compatible with user’s mental model of

motion

7. Ecological interface design• close correspondence with environment

being displayed

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Principles Based on Attention

8. Minimizing information access costs• important or frequently accessed info is easy

to access

9. Proximity compatibility principle• close to what it represents• close to its control

10. Principle of multiple resources• auditory vs. visual• spatial vs. verbal• (perceptual/cognitive vs. response)

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Memory Principles

11. Principle of predictive aiding• predictive display proactive user

12. Principle of knowledge in the world• don’t overburden human memory

13. Principle of consistency• be consistent

Applications

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Two-Valued Info(Warning and Alert Information)

• Examples• Low oil pressure indicator (automobile)• Door open indicator (aircraft)

• Types• Lights• Flags

• Technologies• Electronic• Mechanical

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Two-Valued Information (2)

Principles• Should attract attention of busy / bored

operator.• Should tell what is wrong.• Should not prevent continued attention

to other duties.• Should not be likely to fail.• Should not give false alarms.

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Quantitative Information(Exact Reading)

• Examples• Oil pressure (psi)• Speed (mph)• Temperature (deg)

• Types• Counter• Digital display

• Technologies• Electronic (LED, LCD, CRT, …)• Mechanical (drum, disk, …)

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Quantitative Information 1 (cont’)

Principles

• Mount close to panel front to minimize

shadows, etc.

• < 2 changes/second

• 1 : 1 height-to-width ratio

• 1/4 - 1/2 width spacing

• high contrast

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Quantitative Information(Approximate to Exact Reading plus

Rate Info)• Examples

• Altitude (aircraft)• Speed (auto, aircraft)• Temperature (chemical reactor)

• Types• Fixed scale moving pointer• Fixed pointer moving scale

• Technologies• mechanical, electromechanical• electronic (CRT, LCD, …)

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Fixed Scale Moving Pointer (1)

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Fixed Scale Moving Pointer (2)

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Fixed Pointer Moving Scale (1)

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Fixed Pointer Moving Scale (2)

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Quantitative Information (2)

Principles

• Scale range

• Interval values

• Scale dimensions

• Scale layout

• Pointers

• Motion

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Scale Range

• Select least precise scale that meets operator’s needs.

• Display in immediately usable form, e.g.+ 0% - 110% maximum RPM

rather than

- 0 - 8250 RPM

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Scale IntervalsGood progressions

0.10.2 0.3 ... (0.1 unit numbered interval)1 2 3 ... (1 unit)5 10 15 ... (5 units)

Fair progressions0.20.4 0.6 ... (0.2 unit)2 4 6 ... (2 units)

Poor progressions0.25 0.5 0.75 ... (0.25 units)4 8 16 ... (4 units)1 3 5 ... (2 units, poor initial point)

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Recommended minimum scale dimensions (in)for low illumination - 0.03 to 1.0 ft - L

(28-in. viewing distance).

Adapted from Human Factors in Engineering and Design (figure 5-4)

Scale Dimensions

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0.160.10 MINIMUMSEPARATION

major scale marker

minor scale marker

intermediatescale marker

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Scale Layout

• Circular

• Numbers increase clockwise

• Zero break

• Zero at bottom (positive scale)

• Zero at 9 o’clock position (positive -

negative scale)

• Numbers inside graduation marks

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Circular Display

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Positive/Negative Display

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Linear Displays

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Linear Displays (2)

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Pointers

• To but not over minor scale markings

• As close to surface as possible (parallax)• Same color as dial markings• Pointer tip angle20 degrees

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Long-Scale Displays: Multiple Pointer

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Long-Scale Displays: Pointer/Counter

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Motion(Fixed Pointer Moving Scale)

• Scale numbers increase in clockwise direction

• Compatible control / scale movement

• Clockwise control movement

increases value

• Avoid FPMS displays (inconsistency)

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FPMS Anomalies (1)

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FPMS Anomalies (2)

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Check Reading• Examples

• RPM ok?• Temperature ok?

• Types• FSMP• FPMS

• Technologies• Mechanical• Electronic (CRT, LCD, …)

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Check Reading (2)

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Check Reading (3)

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Current Setting Info(Quantitative)

• Examples• Frequency selector (radio)• Channel selector (TV)

• Types• FSMP• FPMS (?)

• Technologies• Mechanical• Electronic

• Principles• see “quantitative info principles”

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Current Setting Info(Qualitative)

• Examples• Function selector (stereo system)• Line selector (multi-line phone)

• Types• Two-value displays• Alphanumeric displays

• Technologies• Mechanical (e.g. flag, 2-position button)• Electronic (light, LED, …)

• Principles• detectability• discriminability

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Complex SystemState / Status Info

• Examples• Fuel system state (aircraft)• Switch settings (railroad switch yard)

• Types• Pictorial

• Technologies• Electronic

• Principles• Pictorial realism• Compatibility with mental model

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Pictorial Display(System Synoptic)

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Command Info

• Examples• Heading to waypoint (aircraft)• Collision avoidance maneuver

(aircraft)

• Types• FSMP / FPMS• Alphanumeric• Pictorial

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Command Info (2)

• Technologies• Mechanical• Electronic

• Principles• Tell operator what to do

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“Pathway in the Sky” Display

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Navigational Info

• Examples• Horizontal Situation Indicator (HIS) -

(aircraft)• Map display (car)

• Types• Pictorial

• Technologies• Electronic (CRT, LCD)• Optical projection (projector, HUD)

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Navigational Info (2)

• Principles• North-up for planning• Track-up (ego-centered) for control• Safety considerations

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Horizontal Situation Indicator (HSI)

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Automobile Map Display

Other Kinds of Displays

Head-Up Display

windscreen

mirrorprojector

pilot’seye

combiner

HUD image (at optical infinity)

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Head-Up Display

Source: http://ef2000_www.im.gte.com/efhcphd.html

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Military Aircraft HUD

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Head Mounted Display

Kopin Monocular Head Mounted Displayhttp://www.phoenix.net/~vrgear/kopin.htm

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Helmet Mounted Display

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Head Mounted Display

http://www.keo.com/Hmds.html

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Head Up Display

F-22 Simulator Solid Statehttp://www.keo.com/F22hud.htm

Head down displayhttp://www.keo.com/hdd.htm

Head Down Display

Haptic Display. Exoskeletonhttp://www.stelarc.va.com.au/exoskeleton/

Haptic Display

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Haptic Display

PHANToM haptic interfacehttp://web.mit.edu/newsoffice/nr/1998/phantom.html

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Haptic Display

A haptic display based on the Tactile Flow concepthttp://www.piaggio.ccii.unipi.it/robotics/robresearch/haptic.html

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Feedback Displays

Pediatric Intravenous Catheterization Simulatorhttp://www.immersion.com/pdf/ctsmmdl2.pdf

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Feedback Displays

Event For Extended Body And Walking Machine

http://www.stelarc.va.com.au/exoskeleton/