Download No.4

Spatiotemporal
Information Processing
No.4
3 components of Virtual Reality-3
Display System
Kazuhiko HAMAMOTO
Dept. of Information Media Technology,
School of Information and Telecommunication Eng.,
Tokai University, Japan
Today’s Contents
 Somatic sense



Skin sense
Deep sense
Haptic sense
 Display system – skin sense

The principle of tactile primary color
 Display system – deep sense
 Display system – haptic sense
The relationship
among 3 components (review)
real space
virtual space
Display system
Person
Simulation system
Sensing system
computer
Somatic sense (1/4)
Cutaneous sense (or sense of
touch or skin sense)
A
sense by some sensory receptors
which lie beneath the surface of the
skin
 tactile sense, temperature sense,
pain sense
Somatic sense (2/4)
Deep sense (or proprioceptive
sense)
A
sense of the relative position of
neighboring parts of the body,
whose receptors are found in
muscles, tendons and joints
 kinetic sense, postural sense
Somatic sense (3/4)
How can “iron ball” be felt by
human sense ?
 Shape
Skin
?
sense or deep sense
 Surface
Skin
pattern (texture) ?
sense or deep sense
 Recognition
of “iron” ?
Somatic sense (4/4)
 Recognition of shape
 If we wear gloves….
 We can feel -> deep sense
 Recognition of pattern
 If we wear gloves….
 We cannot feel -> skin sense
 Recognition of “iron”
 Temperature sense
Haptic sense
“Active touch” can improve the
precision of the recognition
Haptic sense
 Active
touch sense, which is
integrated sense of skin sense
and deep sense with action of
the body
Skin sense and receptors
 Tactile sense
Merkel disk
displacement
 Meissner corpuscle
velocity
 Ruffini corpuscle
displacement

 Sense of contact
force (pressure)
Ruffine corpuscle
displacement
 Pacinian corpuscle
acceleration

http://www.unmc.edu/physiology/Mann/mann5.html
Skin sense and receptors
Deep sense and receptors
 Receptor in muscle


Muscle spindle
Stretch receptor, which sends muscle’s
length information to CNS
 Receptor in tendon (joint)


Golgi tendon organ
Another type of receptor, which provides
information about changes in muscle
tenstion
Muscle spindle
CNS : Central nervous system
http://www.ucl.ac.uk/~sjjgsca/MuscleControl.html
Golgi tendon organ
Display system – skin sense
 Virtual sandpaper (M.Minsky, MIT, 1995)
Recognition of “type of Texture”
 Fine uneven surface

 Vibration

of small amplitude, high frequency
Rough uneven surface
 Vibration
of large amplitude, low frequency
Virtual Sandpaper
Margaret Minsky, MIT, 1995
Screen image
Experimental setup
http://dspace.mit.edu/handle/1721.1/29094
Display system – skin sense
 The principle of tactile primary colors



A kind of functional electrical stimulation
(FES)
Each receptor is stimulated electrically and
independently
3 receptors can be stimulated
independently by the differences of how
deep seated or singularity of feature along
axone.
Prototype using the principle of
tactile primary colors
 Sense of pressure,
Prototype of the tactile display
low and high freq.
vibration can be
presented (2005)
http://www.star.t.u-tokyo.ac.jp/projects/tactile-display/index-j.html
Display system – deep sense
 Equipment type
A display device is equipped on hand
or fingers.
 Action of hand or fingers is restricted
by the display device.
 The restriction causes a feeling of
“existence of an object”

Display system – deep sense
Cyber Grasp
Display system – deep sense
 SPIDAR
 8 wires and 8 motors
detect the position and
the direction of the ball
 User controls the ball
in 6DOF
 Sense of touch or
collision is
transformed to tension
of the wires
http://www.ddd.co.jp/product/spidar/
Display system – Haptic sense
 Haptic display
Present tactile information
 Stimulus of tactile organ
 Force feedback system
 Shape, hardness, softness,
smoothness, friction and gravity are
perceived in virtual space.

Display system – Haptic sense
 PHANToM Desktop (SensAble Device, Inc.)
 6DOF
 Refresh rate
 1000 [Hz]
 Simple structure
 Torque generated
by motors is
transmitted to
active part by wire.
Display system – deep sense
Problems
 Always
feel a display’s weight
and movement
 Difficult to create “we don’t touch
anything”
 Response of a motor (actuator)
Novel Development in my Lab.
 Deep sense
 Artificial muscle is
used as switching
device
Haptic interface
Actuated with
Magnetorheological fluid
 Skin sense
Uneven feeling
and
can be realized by
Artificial
muscle
MR fluid
HAMAデバイス

Novel Development in my Lab.
Power supply
MR fluid for sense of
cutaneous
Artificial muscle switch
for deep sense
Electric circuit for drive
New haptic
device
New device for deep sense with
Artificial muscle
Lock by BMX
Unlock by BMX
movable part
Restricted finger
Released finger
New device for skin sense with
MR fluid
When MR fluid into electro magnetic field, the viscosity becomes higher