Detecting Shape Deformation of Soft Objects Using Directional Photoreflectivity Measurement (UIST 2011)
1. Detecting Shape Deformation of Soft Objects
Using Directional Photoreflectivity Measurement
Keio University / The University of Tokyo
JST ERATO IGARASHI Design Interface Project
Yuta Sugiura, Gota Kakehi, Anusha Withana, Calista Lee, Daisuke Sakamoto,
Maki Sugimoto, Masahiko Inami and Takeo Igarashi
2. Converting Soft Objects
into Interfaces
• Soft objects are common in the home
• This sensor converts them into touch input
devices
3.
4. Using this, we can...
• Use physical actions to control home
appliances and game characters
5. Contributions
1) Measurement of cotton density
using photoreflectors
2) Packaged sensor module
3) Multi-sensor system that
determines the point of contact
4) Example applications
6. Contributions
1) Measurement of cotton density
using photoreflectors
2) Packaged sensor module
3) Multi-sensor system that
determines the point of contact
4) Example applications
7. Measuring the Density of Cotton
• Using photoreflectors
– Infra-red LED
– photo transistor
Photoreflector
Cotton Emitted IR
In low density cotton In high density cotton
9. Comparison of Sensing Method
• Sensors attached on the surface (Yagi et
al. SIGGRAPH ’11)
– The soft properties is changed
• Pressure Sensor
– Measuring small area density changes
only
• Photoreflector (Our approach)
– Able to measure wide range of density
changes
Photoreflector
10. Measurement Experiment
• Polyester cotton
• Reduce the height of the lid
by 2mm each time
• Raise the lid
0
1
2
3
4
0.007 0.01 0.013 0.016 0.019 0.022 0.025 0.028
Voltage(V)
Material Density (g/cm3)
Polyester Co on-Push
Polyester Co on-Pull
Push
Pull
Cover
Soft Material
Photoreflector
(Photo Sensor and IR LED)
146 [mm]
104 [mm]
11. Contributions
1) Measurement of cotton density
using photoreflectors
2) Packaged sensor module
3) Multi-sensor system that
determines the point of contact
4) Example applications
12. Sensor Module
• 6 photoreflectors
arranged orthogonally
• Palm-sized
• Each module works
independently
Li-Po battery
ZigBee
microcontroller
photoreflector
13. Contributions
1) Measurement of cotton density
using photoreflectors
2) Packaged sensor module
3) Multi-sensor system that
determines the point of contact
4) Example applications
15. Interpolation to Determine Position
• Insert Multiple sensor modules
• Sum of 6 photoreflector values in one
module
16. Calibration of the Sensor's Location
1) User inputs the location directly
2) Use an infra-red camera
17. Contributions
1) Measurement of cotton density
using photoreflectors
2) Packaged sensor module
3) Multi-sensor system that
determines the point of contact
4) Example applications
22. Other Possible Applications
• Embedded into a down jacket
– Music player controller
• Embedded into beds and pillows
– Senses the condition of the
sleeping person
25. Conclusion: Converting Soft
Objects into Touch Devices
• Measurement of cotton density using
photoreflectors
• Packaged sensor module
• Multi-sensor system that determines
the point of contact
• Example applications