ARGUS “Assisting peRsonal GUidance System for people
with visual impairment”
Oihana Otaegui
Vicomtech-IK4
ARGUS – European Space Solutions 2012
List of content
 Argus Consortium
 Motivation
 Objectives
 Argus System
 Headphonests
 Argus Preliminary Tests
 Conclusions
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ARGUS – European Space Solutions 2012
ARGUS Project: Assisting personal guidance system for people
with visual impairment
 FP7-ICT-2011-7
 Duration: 30 Months
 Start date: 01.10.2011
 End date: 30.03.2014
 http://www.projectargus.eu/
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Motivation
 Visually disabled people have striking needs for trustful navigation systems
providing them efficient mobility services, mainly considering safety and
autonomy.
 Limitations of existing products and solutions:
• Lack accuracy and integrity: they do not provide a suitable and efficient manmachine interface adjusted to this user segment, or rely on costly
infrastructures.
• Are based on GNSS providing information through graphical displays or verbal
output.
• Are not convenient for people who cannot see or have to operate in
environments where verbal instructions could interfere with other external
sounds.
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Motivation
People with visual
impairment require
guidance support in
outdoor activities.
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Motivation
• GNSS technologies are being
• Track perception will allow blind
implemented in innovative personal people to imagine the geometry of
navigation devices
the path and walk along it.
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Overall Goal
 To develop a GNSS-based mobility service for people with impaired
visually capabilities, to guide them along a pre-defined track, using
acoustic and audio-haptic signals, which meets the level of accuracy and
reliability they need in urban environment for improving their day-to-day
life autonomy
 Other outcomes:
• Develop innovative tools which could help blind and visually impaired people to
move around autonomously and confidently. They could be used also by people
working in low-visibility and hazardous conditions.
• Implemenation of a user-friendly portable satellite-based navigation device with
acoustic and haptic user interfaces enabling users to obtain a 3D spatial insight of
their surrounding environment, and providing continuous assistance to follow a
predefined path in urban, rural or natural areas.
• Retrieve benefits from navigation services to increase the level of positioning
accuracy and reliability as well as the level of service availability.
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ARGUS Guidance Concept
• The sequence of the bell rings allows any
person to build a mental map of the path.
• Although the sound is the same it is perceived
in a different way depending on the distance
and orientation
• ARGUS PROPOSES 3D SOUND FOR GUIDANCE
USING STEREO OUTPUT
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Binaural audio
What are binaural sounds?
Binaural technologies reproduce the interaural differences
(arrival time and amplitude between the ears).
Binaural sounds create the illusion that sounds produced
by a stereo headphone emanate from specific directions
and distances in the surrounding space.
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System Operation
Obtaining Track Data
B. Track on Map Processing
A. Track Recording
C. Track Server
GPX data (Tracks and Waypoints) can be
obtained through different options
GPX data recorded and activated
GPX file is loaded in the user terminal
and activated for track guidance to
reproduce the path and reach the
destination.
Absolute System Reference
User System Reference
Optional
Head
Mounted
Guidance instructions are provided based on user
position and orientation obtained through GNSS and
electronic compass
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Track Recreation
ARGUS – European Space Solutions 2012
System architecture
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Headphone set
Main Objective: The selection and validation of headphones that meet the safety needs
of the blind and partially sighted in outdoor navigation tasks. And specifically,
headphones non-disturbing the general hearing of ambient sounds.
• Headphones non-disturbing the general hearing
•
1. Audiobone
2. Vibe BS NVE
• Normal headphones:
•
3. Elecom
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4. Sennheiser
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Conclusions Headphone set
95% of respondents identified one or more headphone
devices that they thought could be used to safely guide
people outdoors.
40% of users selected the Vibe, 30% Elecon, 19%
Sennheiser and 13% Audiobone.
Argus should be designed to accommodate a wide range
of headphone types, which can then be chosen by each
individual user to meet personal needs and preferences.
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Wizard of Oz
• Develop a tool in order to carry out early tests on binaural sounds
perception and guiding
• Very valuable for user training and to help to define the values of the most
relevant parameters of the Binaural Module of the PPoC
• Binaural Test and Validation Platform
- WYSIWYG style android development tool from Google
• Functionality
- Set of applications for testing and training users.
- Not automated, two person are needed
 Conductor: who triggers and simulated ARGUS operation
 User: who is being guided through a route
- Oral STOP message to avoid risky situations
• Objective
- Get the personalization options for the future ARGUS system
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Sound latency
Orientation perception
Distance between consecutive binaural points.
Velocity between points
Height of the perceived sound
- Trainning
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User Tests: Technical Setup
• Positioning Unit
- GPS L1: u-blox 6T evaluation kit with an USB interface for polling raw GPS L1
measurements and ephemeris
- Power Supply: USB interface
- Antenna: u-blox ANN-MS antenna (active)
 located at the head of the applicant
- notebook used for the position calculation was carried in a backpack
- PVT
 Snap-shot solution for position computation, based on least-square adjustment,
was not adequate
 Enhanced Kalman Filter (EKF) for pedestrian navigation was chosen
 EDAS correction information was not used while operating with the EKF. The
ionospheric influence was reduced using the Klobuchar model
- PPoC Setup
 Code-pseudo-ranges and Doppler information was used with an update rate of 1
Hz
 Position output rate was chosen with 1 Hz
 Following NMEA sentences were forwarded to the Smartphone via Bluetooth
 All output information forwarded to the Smartphone was logged into a file in
the notebook
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User Tests: Technical Setup
• Mobile device
- ASES Eee Pad Transformer Tablet
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Processor: NVidia Tegra 2 @ 1GHz
RAM: 1GB
OS: Android 3.2
Sensors: G-Sensor, 3D Gyroscope, E-Compass, GPS -> IMU used for the PPoC
• Mobile Device Application
- Android operating system using the Android SDK(for GUI) & Android NDK (for core)
- integrates all the other components used at the PPoC
• Navigation Module
- Radius of 2 m was set to define the reaching area for each waypoint
• Binaural Module
- One binaural ring (2m) with sounds each 15 degrees
- Finger Snap sound selected
- Sound duration 1s
• Headset
- Audiobone, Vibe and Senheiser
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User Tests: Test sites
• Open field
- Public meadow near the Airfield Paderborn-Haxterberg
- PPoC user tests
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Test Results: User’ Routes (TRK_U2_01)
• GNSS Reception Environment
- Lower number of used satellites
- No jumping
 Good GNSS position performance
- User walked at higher speed 3-4 km/h
 COG and SOG smoother
• User Graphical Route
- maximum deviation distance by the
external GPS was 3.23 meters
- maximum distance from the reference
track during the first section was less
than one meter
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Test Results: User’ Routes (TRK_U3_02)
• GNSS Reception Environment
- 10 satellites on average: min7 max 11
- a static period of the user of about 30 seconds
- At the last third of the track, the user reduced his
walking speed, when he approached the end
point
• User Graphical Route
- Except the third section, the other are inside the
-/+ 3 meters corridor during most of the time
- Section 2 - 3 very sharp angle. Not very common
in real life. Good overview of the behaviour of
the system and the user. User must make an
orientation change of more than 120º degrees to
the left. The first instruction given by the audio
at the reference point is a 90º change to the left
(it is maximum value). Audio keeps asking for
more orientation change, which may be
perceived by the user as the first instruction
being repeated
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Graphical comparison of heading reaction vs. heading
instructions
• From test TRK_U2_01 and TRK_U3_02, a KML file
has been generated from the internal logs of the
audio played during the tests and the individual
compass heading measurements
- Impossible to plot all the information, only relevant point
selected
- Powerful overview of the performance of the system and
how the user reacts to each order
• Test TRK_U2_01
- a good “order following”
- user reacts correctly to the orders
- The user process correctly the direction of the sound and
therefore the user has no problem following the track
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Graphical comparison of heading reaction vs. heading
instructions
• Zoom view in TRK_U3_02 user test
where a late reaction of the user
can be appreciated.
- The arrows above the white line show the
direction of the played sound to guide the
user
- the user takes a long time to change his
walking direction.
- Although the system is trying to get the
user back to the ideal track the user keeps
deviating due to his late reaction
- To avoid this cases ARGUS system should
increase the sound rate to warn the user
and to encourage him to change his
walking direction
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Numerical track Analysis
Maximum distance (m) to the reference track in each section
Average distance (m) to the reference track in each section
Waypoints pass distance evaluation from the different tests
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Overall Conclusions
• The results of the Preliminary Proof of Concept tests in Paderborn have
been compiled in order to show the first tangible development of the
ARGUS concept.
• Preliminary Proof of Concept of the guidance support system, using
map/tracks, binaural sounds and satellite signals has been tested
successfully with four end-users performing nine navigation tasks
• Although the users were aware that this was a preliminary prototype they
were satisfied with ARGUS system guiding capability, simplicity and non
disturbance of the general hearing
- the binaural guiding principle should be explained in detail before using the system in real
navigation tasks in order to achieve optimum results
• The examined test parameters led to satisfying results with regard to the
early stage of the current development phase
• The interviews highlighted the need of providing personalization options for
the binaural guiding at the final prototype to cope with the high variability
of technical skills and visual capabilities of the end users
• 7 out of 9 tests have an average distance error of below 5 meters to the
ideal track in the four waypoint sections of the proposed route
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Overall Conclusions
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Thanks for your attention
Questions?
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