Closing conference of SYSIASS June 17 th 2014 Assistive
navigation for powered wheelchair Jean-Marc Capron Enseignant -
Chercheur ISEN
Slide 2
Closing conference of SYSIASS June 17 th 2014 Agenda Some
questions (and answers): Why ? Motivations of this work What ?
Objectives How and who ? Presentation of the different scenarii
Where are we ? Summary & Perspectives 2
Slide 3
Closing conference of SYSIASS June 17 th 2014 Motivations
Driving a powered wheelchair can be difficult with some forms of
disability assisted navigation could help some people to use such
an equipment Private homes are usualy not sized for powered
wheelchairs driving assistance can be beneficial to maintain at
home some elder or disabled people 3 MotivationsObjectivesDifferent
scenarii Summary & Perspectives
Slide 4
Closing conference of SYSIASS June 17 th 2014 Objectives Ease
access to powered wheelchairs Improve the autonomy of users Offer
different assistance levels according to users need Be realistic
with the cost of proposed solutions Let the control to user
whenever its possible 4 MotivationsObjectivesDifferent scenarii
Summary & Perspectives
Slide 5
Closing conference of SYSIASS June 17 th 2014 Different
scenarii 1 st level: collision avoidance the wheelchair stops when
an obstacle is too close 2 nd level: obstacle avoidance the
wheelchair deviates when an obstacle is detected 3 rd level:
autonomous navigation the wheelchair can find its trajectory by
itself 5 MotivationsObjectivesDifferent scenarii Summary &
Perspectives
Slide 6
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
collision avoidance objective: the user is in the loop and is the
only driver the wheelchair is stopped before beating an obstacle
(wall, another person, set of furniture) objective: the wheelchair
must be equipped with sensors Ultrasound (US): cheap (10 ), wide
beam slow, sensitive to crosstalk Infrared (IR): cheap (10 ),
instantaneous information very directive Laser / Lidar:
multidirectional detection, instantaneous information expensive
(1000 ), mounting on the wheelchair 6 MotivationsObjectives1 st
scenario Summary & Perspectives
Slide 7
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
collision avoidance objective: the user is in the loop and is the
only driver the wheelchair is stopped before beating an obstacle
(wall, another person, set of furniture) objective: the wheelchair
must be equipped with sensors Ultrasound (US): cheap (10 ), wide
beam slow, sensitive to crosstalk Infrared (IR): cheap (10 ),
instantaneous information very directive Laser / Lidar:
multidirectional detection, instantaneous information expensive
(1000 ), mounting on the wheelchair 7 MotivationsObjectives1 st
scenario Summary & Perspectives
Slide 8
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
collision avoidance 1 st prototype developped at ISEN: 8
MotivationsObjectives1 st scenario Summary & Perspectives
Dupont Medical wheelchair Dynamic Controls electronics system 9 US
sensors 2 IR sensors visual feedback justifies why the wheelchair
is stopped indicates the obstacles on the rear
Slide 9
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
collision avoidance functions achieved by the assistance: 9
MotivationsObjectives1 st scenario Summary & Perspectives the
sensors are activated according to the direction chosen by the user
the speed is decreased according to the distance with obstacles the
wheelchair is stopped when the distance is below a certain
threshold the assistance can be activated/unactivated thanks to a
key button
Slide 10
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
collision avoidance 1 st prototype developped at ISEN: 10
MotivationsObjectives1 st scenario Summary & Perspectives
Slide 11
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
collision avoidance 1 st prototype developped at ISEN: 11
MotivationsObjectives1 st scenario Summary & Perspectives
Slide 12
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
clinical tests 12 MotivationsObjectives1 st scenario Summary &
Perspectives Clinical tests at Hospital of Garches, France Tests
held during 1 st semester of 2012 Ethics Approvals: clinical
protocol approved by AFSSAPS (French agency for health and sanitary
security) and the CPP (Commission for the protection of people) at
the end of December 2011 Pilot study of 27 users divided into 3
groups Group 1: 9 healthy volunteers who had never driven an
electric wheelchair Group 2: 9 experienced electric wheelchair
users Group 3: 9 users who didnt pass the electric wheelchair
drivers licence
Slide 13
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
clinical tests 13 MotivationsObjectives1 st scenario Summary &
Perspectives Methodology: implement 2 circuits that simulate a real
life indoor environment (walls, doors, obstacles) Goal: reduce the
number and severity of collisions 2 Cartons to simulate daily life
doorways
Slide 14
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
clinical tests 14 MotivationsObjectives1 st scenario Summary &
Perspectives Number of collisions
Slide 15
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
clinical tests 15 MotivationsObjectives1 st scenario Summary &
Perspectives Average time in seconds
Slide 16
Closing conference of SYSIASS June 17 th 2014 1 st scenario:
clinical tests 16 MotivationsObjectives1 st scenario Summary &
Perspectives conclusions of these first tests: The users who tried
this 1 st prototype of the device didnt find it very useful They
have the feeling that the device is not able to help them (it just
slows down the progress of the wheelchair) A technical aid which
seems useful from a scientific and medical point of view is not
necessarily accepted by the users The implementation of the 2 nd
scenario is necessary
Slide 17
Closing conference of SYSIASS June 17 th 2014 2 nd scenario:
obstacle avoidance objectives: the user sets the main direction the
wheelchair deviates around an obstacle the wheelchair is no longer
stopped so easily corridor travelling is eased passing through a
doorway is eased methodology: potential field (the wheelchair is
pushed away by obstacles) 17 MotivationsObjectives2 nd scenario
Summary & Perspectives
Closing conference of SYSIASS June 17 th 2014 2 nd scenario:
obstacle avoidance several prototypes developped at ISEN &
University of Canterbury: 19 MotivationsObjectives2 nd scenario
Summary & Perspectives Invacare wheelchair Dynamic Controls
electronics system 9 US sensors 4 IR sensors visual feedback on PC
mainly used for debugging ISENs chair:
Closing conference of SYSIASS June 17 th 2014 2 nd scenario:
obstacle avoidance 2 prototypes developped at University of Kent:
22 MotivationsObjectives2 nd scenario Summary & Perspectives 1
custom-built + 1 Invacare wheelchairs 1 custom-built + 1 Dynamic
Controls electronics systems 8 US sensors IR sensors haptic
feedback (vibrating joystick) 2 line IR cameras
Slide 23
Closing conference of SYSIASS June 17 th 2014 2 nd scenario:
obstacle avoidance 23 MotivationsObjectives2 nd scenario Summary
& Perspectives Univ. of Kents chair: corridor navigation
Slide 24
Closing conference of SYSIASS June 17 th 2014 2 nd scenario:
obstacle avoidance 24 MotivationsObjectives2 nd scenario Summary
& Perspectives Univ. of Kents chair: doorway passing
Slide 25
Closing conference of SYSIASS June 17 th 2014 2 nd scenario:
obstacle avoidance navigation algorithm is currently transfered to
wheelchair for clinical tests at Kent and Canterbury Hospital.
Approval for clinical tests has been obtained in May 2014. 25
MotivationsObjectives2 nd scenario Summary & Perspectives
Slide 26
Closing conference of SYSIASS June 17 th 2014 3 rd scenario:
autonomous navigation objective: the wheelchair finds its way by
itself Robot Operating System (ROS) for navigation & control
(embedded PC core i5) 16 US sensors 2 Hokuyo Lasers 1 Kinect sensor
26 MotivationsObjectives3 rd scenario Summary &
Perspectives
Slide 27
Closing conference of SYSIASS June 17 th 2014 3 rd scenario:
autonomous navigation 27 MotivationsObjectives3 rd scenario Summary
& Perspectives Univ. of Essexs chair: doorway passing
Slide 28
Closing conference of SYSIASS June 17 th 2014 Summary Several
wheelchairs prototypes developed by 3 partners Collision avoidance:
low-cost solution clinical tests achieved at Hospital of Garches
& Institut La Vie Devant Soi moderate acceptance by users
Obstacle avoidance: low-cost solution prototypes in final phase of
development eases corridor navigation & doorway passing
clinical tests planned at Hospital of Kent in next months 28
MotivationsObjectivesDifferent scenarii Summary &
Perspectives
Slide 29
Closing conference of SYSIASS June 17 th 2014 Summary
autonomous navigation: mid-cost solution efficiency demonstrated
for doorway passing 29 MotivationsObjectivesDifferent scenarii
Summary & Perspectives
Slide 30
Closing conference of SYSIASS June 17 th 2014 Perspectives
validate with next clinical tests if current approach is sufficient
to fulfil the needs of users finalize a common platform for all
partners 30 MotivationsObjectivesDifferent scenarii Summary &
Perspectives
Slide 31
Closing conference of SYSIASS June 17 th 2014 Acknowledgments
31 MotivationsObjectivesDifferent scenarii Summary &
Perspectives Hpital et Fondation de Garches Association La Vie
devant Soi Centre Hlne Borel Kent Hospital