Article published on juin 2008Virtual reality
Vibee: communication through vibrations
The Vibree vibrotactile interface improves the realism of virtual reality devices by warning the user against the proximity of a critical region or possible contact with an object to be avoided. Developed in collaboration with PSA, it supplements force-feedback arm devices. A fully operational prototype is available.
Immersed in a virtual reality
environment, you attempt to
remove a bolt in an automobile
engine, at approximately ten
centimetres from a red-hot part...
A sharp turn of the key, and your
elbow comes dangerously close
to this part: a slight, continuous
vibration in the elbow warns you of
the danger. A new turn of the key
and your below touches the hot
metal: this time, you are warned by
intense and repeated vibrations.
The bolt is still not loose and you will
need to be more careful.
This simple example illustrates the
interest of the Vibee vibrotactile
interface developed by CEA LIST's
sensorial interface laboratory for
PSA requirements: it significantly
improves the realism of simulated
scenes. 'The force feedback arm
has the disadvantage of limiting the
operator to the hand that moves it',
explains Samuel Roselier (CEA LIST),
'whereas in a real situation the entire
body is involved, hence the interest
of enlarging the simulation'.
Vibee achieves this by emitting
vibrations of controlled intensity
(50 to 120 Hz) and duration
(continuous, one-second intervals,
several seconds). This 'vibrotactile
language' is easily understood by
the user, whose movements are
unhindered: the module weighs
approximately 30 grams and
occupies a volume of less than 20
cm3. It can be attached directly
on the skin or secured to a part of
the body by a flexible strap. The
presence clothing does not alter the
perception of the vibrations.
Spatial tracking of the body part
to be monitored (the elbow in this
example) is performed by a localised
3D motion capture device. 'As soon
as a critical region is approached,
Vibee begins to vibrate in less than 50 milliseconds', explains Samuel
Roselier.
Based on the current prototype
(currently being tested at PSA), the
laboratory estimates that the series
production cost of Vibee would
amount to a few tens of euros per
unit, which is little in comparison
with that of a feedback force
interface (thousands of euros).
In addition, combined with
accelerometers, the vibrotactile
interface could be used for
other applications currently
being explored by CEA LIST in
collaboration with specialists at
CEA/LETI, e.g. refining the speed
and accuracy of sports gestures
(triggering vibrations in case of
deviation), practicing the handling
of very fragile parts, learning delicate surgery gestures, etc. In
all such applications, sensory data
would be associated with motion
capture data.
The laboratory offers industrialists
an adapted prototype to perform
demonstrations tailored to their
activities. It is also searching for an
external partner interested in mass
producing the product.
