Spatiotemporal Information ProcessingNo.43 components of Virtual Reality-3Display 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)

Person

real space virtual space

Simulation system

Display 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 pattern (texture) ?

Skin 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

Skin sense and receptors

http://www.unmc.edu/physiology/Mann/mann5.html

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

http://www.ucl.ac.uk/~sjjgsca/MuscleControl.html

CNS : Central nervous system

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

Experimental setup

Screen image

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, low and high freq. vibration can be presented (2005)

Prototype of the tactile display

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

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 – deep sense

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)

Deep sense Artificial muscle is

used as switching device

Skin sense Uneven feeling

can be realized by MR fluid

Haptic interfaceActuated withMagnetorheological fluid andArtificial muscleHAMA デバイス

Novel Development in my Lab.

Novel Development in my Lab.

Power supply

New haptic device

Electric circuit for drive

Artificial muscle switch for deep sense

MR fluid for sense of cutaneous

New device for deep sense with Artificial muscle

movable part

Lock by BMX Unlock by BMX

Restricted finger Released finger

New device for skin sense with MR fluid

When MR fluid into electro magnetic field, the viscosity becomes higher