Thursday, December 31, 2009

Soft robots preview videos come online!!

Happy New Year!!
Finally, my robot videos are here, on the last day of the year 2009!

After searching around for a host server, I decided that the good old YouTube was still the best so far. My last post was some preliminary tests on video linking. Now let's check out some preview videos of my soft-bodied caterpillar robots!!

First off, the InchBot I-III are the early versions of the my soft robot implementation, dated back to March 2009. It's a process by which I developed inching gaits and learned about frictional control. My colleague Chris successfully modeled these Early InchBots in a finite element environment as well. He really spiced up the video, too.

Then, here come the InchBot IV-VII which twitch, inch, burrow, and climb with much smaller body size. Chris also implemented the InchBot-V in FEA. These soft robots featured open-loop robust inching/crawling/climbing gaits.

Finally, the newest class of caterpillar soft robots, GoQBot, have an escape ballistic rolling behavioral inspired by the caterpillar of Pleuroptya ruralis (mother-of-pearl moth). This class of robots can initiate a rolling behavior within 300ms and hit top speed over 15cm/s. In addition, the updated versions have include almost all the previous InchBot series capabilities and are radio controlled fully untethered. Simple intelligence is implemented into the body structures and active sensing will be next. To hear more, stay tuned to my publications coming soon.

Wednesday, December 16, 2009

Interesting videos of caterpillers!!

Everybody in my lab knows me for training caterpillars to perform various sportive activities. Well, inducing caterpillars to crawl underwater was a true story. My motivation was to test the role of gravity and external pressure on a behaving animal. As it turned out, 5th instar caterpillars float in water and thus experienced a force negative to gravity, but none of the kinematics characteristics changed. See my video "Manduca underwater walk" on YouTube.

Looking closely, I found that bubbles could be seemed to come out of the spiracles as the animal compressed itself. This observation illustrated the potential change of body volume due to tracheal compression (see video). If caterpillars can squeeze air out under the influence of water pressure, they must perform quite a lot of gas exchange in the air. In other words, locomotion facilitates gas exchange by compressing and squeezing the air out of the trachea.

Finally, I would like to share a video I shot the other day when one big caterpillar was crawling on top of a smaller one. It's quite an pathetic scene because the smaller caterpillar was actually in the molting process and could not fight back. Nevertheless, as the big caterpillar crawled along, I observed appropriate deformation on the substrate (in this case another caterpillar) as illustrated by my new ground reaction forces paper (to appear in Journal of Experimental Biology).

Tuesday, December 8, 2009

The missing post released!!

Dear readers,

There has been one missing post about the DARPA meeting which I started back in October but never finished. The reason was quite simple: I wanted to wait for better graphics. In any case, since I was orchestrating the live robotic demos for Tufts, there was no way I could take photographs as I always do. It turned out that it was not allowed anyways. DARPA actually hired prefessional film crew and photographers for the event.

Two months has gone by since the event so it's not news anymore. Nevertheless I thought some of you might be interested in reading my story a few days before the meeting! Now, according to the non-disclosure document I signed, I am not supposed to share anything I saw at the meeting. So in this post, I simply described what happened the very last week before the meeting in the labs. The ME professor that I worked with on this project said: "(It was) the most stressful/intense academic experience that I've gone through". Indeed, for the last month we worked at least 15 hours everyday. To hear more, see October 11 post which is newly released.