experimental haptics lecture1 - stanford...
TRANSCRIPT
![Page 1: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/1.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
CS 277 - Experimental Haptics Lecture 12
Haptic Illusions
![Page 2: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/2.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
A list of illusions that we will cover
• Rendering 3D shapes using 2 DOFs – i.e. how to project positions and forces on smaller rank vectorials
spaces
• Rendering 2D shapes using 1 DOF – i.e. how work can be your ally (and your enemy)
• Rendering small bumps to feel large – i.e. how our sensitivity to force direction is not that good
• Rendering large virtual environments using small devices
– i.e. how to take advantage of humans’ poor perception of position
• Rendering fast cars without moving much – i.e. our vestibular sense is also pretty limited
![Page 3: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/3.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
2-DOF Haptics
DEMO
![Page 4: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/4.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering 3D shapes using 2 DOFs
Why would you want to do this?
• Assume a 2 sensor 2 actuator device
• Try to render a 3D world through it
![Page 5: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/5.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering 3D shapes using 2 DOFs
• Very similar to what we just described for textures
• Basically, assuming interaction with surface z = g(x, y)
– 3DOF device: F = -r(p) n
– 2DOF device: Flateral = -r(p) grad(g)
![Page 6: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/6.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering 3D shapes using 2 DOFs
• Assuming constant penetration > 0
– you can feel a lateral force proportional to the steepness of you plane
– as you move your device across the surface
• In other words, we’re projecting the force on the display of the device
![Page 7: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/7.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
A list of illusions that we will cover
• Rendering 3D shapes using 2 DOFs – i.e. how to project positions and forces on smaller rank vectorials
spaces
• Rendering 2D shapes using 1 DOF – i.e. how work can be your ally (and your enemy)
• Rendering small bumps to feel large – i.e. how our sensitivity to force direction is not that good
• Rendering large virtual environments using small devices
– i.e. how to take advantage of humans’ poor perception of position
• Rendering fast cars without moving much – i.e. our vestibular sense is also pretty limited
![Page 8: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/8.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
1-DOF Haptics
DEMO
![Page 9: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/9.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering 2D shapes using 1 DOF
Why would you want to do this?
• Assume a 2 sensor 1 actuator device (asymmetric device)
• Try to render a 3D world through it
![Page 10: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/10.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering 2D shapes using 1 DOF
• When moving to the left you load a spring for free
• Good news: this extra work gives you the impression of touching a 2D object
• Bad news: surface will feel extra active
![Page 11: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/11.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
A list of illusions that we will cover
• Rendering 3D shapes using 2 DOFs – i.e. how to project positions and forces on smaller rank vectorials
spaces
• Rendering 2D shapes using 1 DOF – i.e. how work can be your ally (and your enemy)
• Rendering small bumps to feel large – i.e. how our sensitivity to force direction is not that good
• Rendering large virtual environments using small devices
– i.e. how to take advantage of humans’ poor perception of position
• Rendering fast cars without moving much – i.e. our vestibular sense is also pretty limited
![Page 12: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/12.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering small Bumps to Feel Large
• our force direction perception
– is poor
– can be greatly influenced by visual feedback
• You can take advantage of this and make smaller bumps feel larger by “cheating” visually
![Page 13: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/13.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
A list of illusions that we will cover
• Rendering 3D shapes using 2 DOFs – i.e. how to project positions and forces on smaller rank vectorials
spaces
• Rendering 2D shapes using 1 DOF – i.e. how work can be your ally (and your enemy)
• Rendering small bumps to feel large – i.e. how our sensitivity to force direction is not that good
• Rendering large virtual environments using small devices
– i.e. how to take advantage of humans’ poor perception of position
• Rendering fast cars without moving much – i.e. our vestibular sense is also pretty limited
![Page 14: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/14.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Exploring Large Workspaces
![Page 15: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/15.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Control Paradigms
Position
Indexing
Position
Scaling
Rate
Control
![Page 16: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/16.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Position and Scaling
• Most common control paradigm.
• Bijective mapping between physical and virtual workspace.
• Loss of spatial resolution when high scaling factors are used.
K:1
![Page 17: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/17.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Indexing
• Manual shifting of workspace through clutching or lifting of device.
• Additional user button required.
• Not optimal for small devices.
![Page 18: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/18.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rate Control
• Position command is translated into a desired velocity of the cursor.
• Low bandwidth.
• Access to unlimited workspace
![Page 19: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/19.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Haptic Perception Discrimination of Force Direction
visual perception haptic perception
q
discrimination angle
![Page 20: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/20.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Haptic Perception Discrimination of Hand Motion
Direction in Free Space
hand motion discrimination angle
q
visual perception
![Page 21: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/21.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Haptic Perception Experimental Results
haptics perception discrimination angles visual perception
Median: 19 deg ( C.I 95% [17,
22] )
Angle [DEG]
Median: 27 deg ( C.I 95% [25,
30] )
Angle [DEG] F
ree
Sp
ace
C
on
tact F
orc
es
![Page 22: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/22.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Workspace Mapping
Simulation Environment
Haptic Interface
hx
xwx
hx
( )hf x
Haptic Device Criterion Function:
Workspace Expansion
( )hf x
![Page 23: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/23.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Workspace Expansion Device Dependent Haptic Criteria
2
0( )1( )
2
hh
w
x xf x
r
0( ) hh
w
x xf x
r
Normalized Distance from center of workspace:
0x
hx wr
hx
0x : position of origin
: current position of haptic device
: workspace radius
![Page 24: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/24.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
maxq
Perception
Cone
Drifting the Workspace
Simulation Environment
Haptic Interface
hx
Workspace Drift
( )w drift hx r f x
wxhx
xwx
hx
( )hf x
Criterion Function
Workspace Expansion
maxsin( )drift hr x q
sin( ) ( )p h hx f xq
( 1)thx ( )thx
![Page 25: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/25.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Drifting the Workspace
Workspace Expansion
![Page 26: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/26.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Drifting the Workspace
Workspace Expansion
![Page 27: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/27.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Drifting the Workspace
( )hf x
wx
hx
Workspace Expansion
Workspace Drift:
sin( ) ( )w p h hx x f xq
![Page 28: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/28.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Drifting the Workspace
( )hf x
Workspace Drift:
wx
hx
Workspace Expansion
sin( ) ( )w p h hx x f xq
![Page 29: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/29.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Drifting the Workspace
Workspace Expansion
![Page 30: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/30.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
A list of illusions that we will cover
• Rendering 3D shapes using 2 DOFs – i.e. how to project positions and forces on smaller rank vectorials
spaces
• Rendering 2D shapes using 1 DOF – i.e. how work can be your ally (and your enemy)
• Rendering small bumps to feel large – i.e. how our sensitivity to force direction is not that good
• Rendering large virtual environments using small devices
– i.e. how to take advantage of humans’ poor perception of position
• Rendering fast cars without moving much – i.e. our vestibular sense is also pretty limited
![Page 31: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/31.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering fast vehicles without moving much
Simulators
![Page 32: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/32.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering fast vehicles without moving much
Simulators
Basic issue:
• Platform (left) has limited workspace, plane (right) doesn’t
![Page 33: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/33.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering fast vehicles without moving much
Simulators
Washout filters trick the user’s vestibular sense by
• Splitting accelerations into low and high frequency components
• Applying high frequency components directly (as they require limited workspace)
• Applying low frequency components by taking advantage of gravity (tilting the platform)
![Page 34: experimental haptics lecture1 - Stanford Universityweb.stanford.edu/class/cs277/resources/lectures/CS277-L12-Illusions2.pdfA list of illusions that we will cover •Rendering 3D shapes](https://reader033.vdocuments.us/reader033/viewer/2022060602/605702998533ca1a2904e192/html5/thumbnails/34.jpg)
CS277 - Experimental Haptics, Stanford University, Spring 2014
Rendering fast vehicles without moving much
Simulators
Why does this work?
• Platform tilting is not perceived if it happens slower than 3 DEG/sec