Hap tics‘Touch the virtual’

Technical Seminar on

PHANTOM ( hap tics tech)

‘Haptics’ is derived from the Greek word ‘haptikos’which means-”being able to come into contact with”

THE SCIENCE OF TOUCH

Virtual Reality

• Virtual reality is a form of human-computer interaction providing a virtual environment that one can explore through direct interaction with our senses.

• It’s a mere imitation of the real world.

• BUT IS IT COMPLETE???

The real world

Our primary interface with the real world is our haptic sense (sense of touch).

How important is our sense of touch?

In order to complete the imitation of the real world one should be able to interact with the environment and get a feedback.

User should be able to touch the virtual object and feel a response from it.

This feedback is called Haptic Feedback.

Basic idea

Haptics, is the technology of adding the sensation of touch and feeling to computers.

A haptic device gives people a sense of touch with computer-generated environments, so that when virtual objects are touched, they seem real and tangible.

Understanding and enabling a compelling

experience of Presence not limited to "being there", but extended to "being in touch" with remote or virtual surroundings

The Technology

Haptics is implemented through different type of interactions with a haptic device communicating with the computer. These interactions can be categorized into the different types of touch sensations a user can receive:

Tactile feedback Force feedback

Data transfer

• Virtual Reality Modeling language (VRML)

• Tells the interface how much force the haptic device should return when it is touched.

How it works?

Phantom device

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It works by monitoring the position of a users fingertip or hand through optical encoders attached to the device

The geometric, material, kinematic, and dynamic properties of the world we wish to represent can be modeled and stored.

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Three Enabling Observations Force and motion are the most important

hap tic cues

Many meaningful hap tic interactions involve little or no torque

A small wrist-centered workspace is sufficient

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Force and motion are the most important hap tic cues

A significant component of our ability to "visualize," remember and establish cognitive models of the physical structure of our environment systems from hap tic interactions with objects in the environment.

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Many meaningful hap tic interactions involve little or no torque

The most significant design feature of the Phantom is the passive, 3 degree-of-freedom "thimble-gimbal.“

Introducing three passive freedoms with the "thimble-gimbal" greatly simplifies programming as well as mechanism design

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A small wrist-centered workspace is sufficient

Many meaningful hap tic interactions occur within the volume that the finger tip spans when the fore-arm is allowed only limited movement

PHANTOM should be constructed such that a user could move the wrist freely without encountering the edges of the workspace

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Three Necessary Criteria for an Effective Interface

Free space must feel free

Solid virtual objects must feel stiff

Virtual constraints must not be easily saturated

PHANTOM Mechanics

Virtual Worlds

Perceptual Observations

Haptic devices

It allows users to touch, feel and manipulate

3-D objects in virtual environments.

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How are Haptic devices different?

• Common interface devices like mouse and joystick are only input devices. No feedback.

• Haptic devices are input-output devices.

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THE NOVINT FALCON

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THE NOVINT FALCON

The Novint Falcon is the first haptic interface device to

bring 3D touch.

As the Novint Falcon is moved, the computer keeps track of a 3D cursor.

When the 3D cursor touches a virtual object, the computer registers contact with that object.

And updates currents to motors in the device to create an appropriate force to the device’s handle, which the user feels.

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Exoskeletons

large and immobile systems that the user must attach him or herself to.

their large size and immobile nature allow for the generation of large and varied force information.

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Gloves and wearable devices

The user can move naturally without being weighed down by a large exoskeleton or immobile device

E.g.Hand Master

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Working

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Locomotion interface and full body force feedback

In a confined space, simulate unrestrained human mobility such as walking and running for virtual reality.

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Tactile displays

Tactile feedback tells us the texture of the surfaces.

Using this we can feel different surfaces and slipping sensations can be produced.

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Applications

Virtual reality Virtual surgery Surgery

Tele-presence Tele-presence Human assistive devices Slide 23

Games & many more…

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Surgery

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Tele-presence

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Conclusion

The development of the PHANTOM device has demonstrated the feasibility of a relatively low-cost system which can provide convincing sensations of interactions with virtual object

With the evolution of this device ,today multiple finger interactions and multiple user interactions in shared workspaces with the device

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Reference

www.globalhaptics.com www.worldhaptics.com www.nasa.gov www.immersion.com www.sensable.com www.sarcos.com

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3304/11/2023

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