Haptics & Robotics LabDepartment of Mechanical Engineering

Boğaziçi University

Data-Driven Texture Rendering on an

Electrostatic Tactile Display

Gholamreza ILkhaniPh.D. candidate

Workshop on Electrostatic Tactile DisplayIEEE World Haptics 2017

Fürstenfeldbruck (Munich), GermanJune 6

Electrostatic tactile display evolution

Senseg“Tixel1”

Disney Research “TeslaTouch2”

Tanvas3

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1. “Senseg”, https://www.senseg.com2. “Teslatouch” , https://www.disneyresearch.com3. “Tanvas”, https://tanvas.co

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You feel what you don’t see

“ Texture ”• Texture by its definition is the feel or shape of

a surface or substance.• In haptic science, texture is the quality which

is fashioned virtually and body perceives this virtually created property.

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Psychophysical Evaluation for Quality Extraction

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• Dimensions for texture perception and identification

1) Rough/Smooth 2) Hard/Soft3) Sticky/Slippery4) Warm/Cold • At least two dimensions are necessary for tactile

texture perception and maximum number of these dimensions must be covered for a realistic haptic

rendering“Psychophysical Dimensions of Tactile Perception of Textures” by Okamoto et al., 2013

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“Data-driven or measurement-based haptic rendering ”

An emerging technique which provides an opportunity to record data from real objects and

replay them on a haptic system

Two Hypothesis-Two parts experiments

• Hypothesis1 The data-driven method is more realistic in than

the ones generated with periodic signals.

• Hypothesis2Roughness and stickiness are the primary dimensions in the perception of virtually-

created textures using electrostatic attraction

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Part 1

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Tangential component of

the accelerations(X axis) for 3

materials VS.

square wave with 80Hz,

240Hz,400Hz

Data collection setup

Experimental procedure 11. Scaling of input voltage

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Result 1Lower voltage for data-driven signal

Experimental procedure 1

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2. Texture Similarity Rating

Result 2Higher similarity and classification number for data-drive method

Experimental procedure 1

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3. Multidimensional perceptual space

Result 3Data driven signals are closer

to their corresponding materials

Result 4Dimension 1: RoughnessDimension 2: Stickiness

Experimental procedure 2

12“One hundred data- driven haptic texture models and open-source methods for rendering on 3D objects” by Culbertson et al.

=∑− ∑

Experimental procedure 2

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Sample materials

Experimental procedure 2

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1. Scaling of input voltage

“skipped”

Just done for one material to find the converging scaling value

• Velocity updated for 10 interval• Normal force assumed constant F<0.5N

Experimental procedure 2

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Result 1Pretty acceptable similarity rating

and number of classification

2. Texture Similarity Rating

Experimental procedure 2

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3. Multidimensional perceptual spaceResult 2

• MDF, leather, foam fully rendered

• Plastic mesh and vinyl slightly deviated

• Abs plastic rubber lost fidelity

Result 3Dimension 1: RoughnessDimension 2: Stickiness

Conclusion

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• Type of the input signal is important while rendering a surface.

• Data-driven method is an efficient way for texture rendering.

• Roughness and stickiness are the primary dimensions of texture rendering on an electrostatic tactile display.

• Couldn’t draw any conclusion on effect of velocity.

Future study

• Vision effect on judgment• Effect of frequency on assigned signal• Increase number of material

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Haptics & Robotics LabDepartment of Mechanical Engineering

Boğaziçi University

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QUESTIONS?

Gholamreza Ilkhani, PhD candidatehttp://haptics.boun.edu.tr

Be realistic!