IEEE ICRA 07 materials

ICRA links

• Program
  • Wed, 11 April
  • 14:00-15:22 We C - Chairing session
  • 15:46-16:04, Paper We D9.2 Adhesion paper
  • 16:04-16:22, Paper We D9.3 Stickbybot Design paper
  • 17:18-17:36, Paper We E7.2 Force sensing finger paper
  • Thurs 12 April Banquet
  • Fri 13 April Awards lunch
  • Sat, 14 April -- Biomimetics Workshop

• IEEE ICRA final submissions instructions for papers, videos (Due 31 January)
  • Paper in PDF format
  • One summary PPT slide
  • Text description for the link to the video (what it will show, what player is needed) Summary.txt, Readme.txt
  • Video (5 MB Mpeg4)

Stickybot Design Paper

Dec 31: Paper accepted. Not much in the way of comments, but see if we can attend to the following: Notes:

• Paper is too long (needs to be 6 pages).
• Should add some acknowledgement that the data match that Kendall Peel model about as well as the Frictional Adhesion model. (See PnasAdhesion07)
• See reviewers comments below and some responses to them.

-Main.MarkCutkosky

Additional information on the following issues would be
beneficial for clarifying some of the researchersí choices:

1. The anisotropic hairs (fourth hierarchical level)
measure 380 micron and have a triangular tip. According to
Gao and Yao (Proceedings of the National Academy of
Sciences of the USA, 2004, Vol. 101, no. 21, pp. 7851-7856,
May 17, 2004), however, robust optimal adhesion is achieved
when the contact size is reduced to around 100 nanometers,
a critical size scale in which the adhesion strength
becomes insensitive to small deviations from the optimal
shape. For larger sizes, the theoretical pull-off force
cannot be achieved unless full contact is achieved by
pressing the fiber hard enough against the substrate before
withdrawal. 

Well... not quite. The bit about Yao and Gao is right and we should cite the reference. But the "pressing hard enough" is the wrong idea -- the point we want to make is that these patches self-adhere. The robot just needs to be compliant enough and apply the shear force in the right direction.

More information about the authors' motivation
when selecting the size of the hairy structure as well as
discussing the (eventual) risk of instability would be
helpful.

Instability is a bit of an issue... but the main issue is if you pull too hard they start to slip and then adhesion goes way down -- unlike the case with geckos. Some of this detail is more relevant to the other paper...

2. Shape of hairy structure: Would a curved tip (like in
geckoís) lead to optimized adhesion?

Good question... but again, detail is more relevant for the other paper.

3. How does Stickybot perform on a lubricated surface, the
fractal character of which is missed within a slippery
interlayer?

Lubrication is problematic -- humidity reduces the van der Waals attraction. Beyond that, it's a question of whether the boundary layer can be displaced. Again, probably more relevant for the other paper.

4. How would Fz be influenced (considering the role of the
tail in preventing pitching), when Stickybot moves
downwards?

Good point -- and relevant to this paper. Stickybot is one-way only for now. Needs to back down. Could remind reader that geckos do reorient their feet on descending.

5. Is there a threshold of lower substrate stiffness? In
other words, how would a compliant surface influence the
performance of Stickybot, regarding the force distribution
and oscillation control?

Not really an issue in my estimation -- the pads should stick fine to anything that is smooth enough. Maybe we will start to have some difficulty with detachment. We should try Stickybot on some shiny vinyl just to be sure. Then we can briefly mention...

Comments on the Video Attachment
================================
Nice video, clear, good material, clear comment (although
too compressed regarding audio quality). 
However no std mpg compression is used, but a
quicktime-variant. Therefore the file cannot be played back
using std. M$ windows mediaplayers

Hmm.. let's fix this.

Whole body adhesion: hierarchical, directional and distributed control of adhesive forces for a climbing robot

• StickyBotDesign_v5.pdf: submitted PDF
• StickyBotDesign_v5.tex: .tex file for submitted PDF
• StickyRefs.bib: Bibliography file -- exported from End Note, I think...
• Other files are on Chewie in RiSE/Papers/StickybotDesignPrinciples

Video

• StickyBot_V4_4H264low-midquality.mov: submitted video.
• FullMovie_V4_4.mov: Full quality version of submitted video.
• Other versions and clips are on Darthmaul in XtraSpace/StickyBot/StickyBot_ICRA07 and on backup DVD.

Adhesion Principles Paper

Dec 31 2006: Paper is accepted. Minor review comments:

I believe that additional comments and explanations on the
following my questions will make the paper more valuable
and reliable.
- How to decide the shape or the angles of the anisotropic
stalks is not clear, while the authors say that it was
found ìempirically.
- How many stalks do the specimen have which was used in
the experiments in Section IV?

We should be able to say the # of stalks per toe and per foot.

1.In section II, the terminologies are confusing.  For
examples, the terms such as shear force, shear load,
adhesive force, normal force and tangential force are used
through out the paper but not explicitly defined.  Are
these forces interchangeable terms or are they different?

Hmmm.. need to go thru and clean up terminology. Adding coordinate system (like we did for the UCSB NSF proposal) might also help.

2.In figure 7, the angle of stalks is stated as 70. 
However it is mentioned at a few place in the paper that it
is 20. It is not consistent.

Easy fix...

3.The forces achieved by isotropic and anisotropic patches
are compared for smooth vertical surface. How smooth is the
surface? Will the smoothness of the surface change the
result? 

Yes for smooth surfaces. We should quantify the smoothness. What is the upper bound on roughness for which they don't work any more?

4.It has been mentioned in the paper that best results are
obtained with the cylinder axes inclined at 20 degrees with
respect to the vertical and slanted tips inclined at 45
degrees with respect to the vertical. Are these values
optimal for a difference surface that the robot walks on?
Can these values be analytically obtained? 

5.What is the work range for the current design?

? Perhaps referring to the workloop analysis as done by Metin Sitti in recent Applied Physics Letters paper? (See PnasAdhesion07).

Directional Adhesive Structures for Controlled Climbing on Smooth Vertical Surfaces

• AdhesionClimbingPrinciples5.7.pdf: Submitted adhesion principles paper
• StickyBotDesign_v5.tex: .tex file for adhesion principles paper
• Bibliography file is same as for the Design Paper
• Other files are on Chewie in RiSE/Papers/AdhesionClimbingPrinciples

Notes:

Paper is too long (needs to be 6 pages). Should add some acknowledgement that the data match that Kendall Peel model about as well as the Frictional Adhesion model. If both papers (Design and Adhesion) are accepted, we could certainly omit the Stickybot photo in this paper to save space. -Main.MarkCutkosky

Embedded Sensors Finger Paper

Dec 31 2006: Paper accepted. Various minor comments from reviewers (see below)

Design of Force Sensing Smart Robot Finger using Embedded Fiber Bragg Grating Sensors via Shape Deposition Manufacturing

• PhotonicRobot_tex.zip: tex files for Photonic Robot paper
• PhotonicRobot_ICRA07.pdf: submitted PDF for Photonic Robot paper
• PhotonicRobotRef.bib: bib file for Photonic Robot paper
• Other files are on Chewie in ylpark/PhotonicRobot/Papers/IEEE_ICRA07

Notes:

• Need to recheck the dynamic test. 10Hz seems really too conservative.

Should try a test where we tap it and look at the ringing frequency... -Main.MarkCutkosky

• Need a little more detailed description of Figure 11. - Yong-Lae
• Isnt' there a possibility that first readers might think the structure deforms really a lot as shown in Figure 9? - Yong-Lae

Review comments:

The only thing I would change would be to explain the SDM
process in a little more detail.  For example, what
materials were used and why?  Also, numbering the steps in
Figure 4 to match the text would be helpful.

A few typos to note include:

section 7

-"demonstratemeasurement"
-"and can measure forces...possible in the future"

The finger only has 4 strain sensors plus one for
temperature compensations.  Using data from these 4 strain
sensors it is shown that the location of a force can be
calculated.  However this is true only if there is a single
contact point.   To be truly useful the finger needs to be
modified and add more force sensors.  Does adding more and
more sensors into the shell change the compliance?  

The shell has a hexagonal pattern.  Why werenít circles
considered?

There are a couple of minor typos.  

Page 3, IV, A ìÖ corresponding to to 0.015NÖî
Page 6, VII,  ìÖ and can measure forces Ö in the future.î
Is repeated.

• 1577.pdf: Stickybot Design Principles as published

• 1873.pdf: Photonic robots as published

• 1693.pdf: Directional adhesion as published