A study has used rodent-like robots to look at the evolutionary development of different mating strategies over an extended period of time. In contrast to direct studies of nature, the observation of robots allows researchers to avoid inherent time-based difficulties of studying evolution, with the results suggesting something a little more complex than the classic one-beats-all natural selection hypothesis.
According to conventional evolutionary theory, a single, optimal phenotype, or mating behavior, should predominate all others, with natural selection taking care of the less efficient strategies. However, in nature we witness a great many populations where this is not the case, and instead see a variety of successful behaviors co-existing. Due to our short life spans, developing an informed theory on why this is the case is decidedly problematic when looking directly at long-term evolutionary cycles in nature.
The study, conducted by Dr. Stefan Elfwing of the Okinawa Institute of Science and Technology, was designed to tackle this long-standing problem of evolutionary theory through the use of robots. Known as Cyber Rodents, the wheeled robots were equipped with cameras for visual detection of energy sources (colored blue) and the rail lamps of other robots (colored green), and infrared communicators for the exchange of genotypes. In biological terms, the Cyber Rodents were hermaphrodites, with all robots in the test able to produce virtual offspring.
During their 288-second life spans, the robots were able to execute two basic tasks – searching for a partner with which to mate, or searching for batteries. The probability of successfully producing offspring was determined by the robot’s internal energy level, thus creating a trade-off between foraging for energy and moving directly to mate.
Dr. Elfwing was able to avoid the inherent time frame difficulties associated with observing evolution in nature, using computer simulation to study over 1,000 generations in each experiment. The results detail the emergence of two distinct behaviors, or phenotypes, within the experiment – the Forager and the Tracker.
The study found that two distinct phenotypes were able to efficiently co-exist (Photo: OIS...
The Forager phenotype would actively search for batteries, only mating when it saw the face of another Cyber Rodent, and never waiting for them to turn around. Conversely, the Tracker would wait for other robots to turn around for mating, with the length of time waited being determined by its current internal energy level.
The experiment was conducted some 70 times with varying results, but it was the experiments where more than one phenotype emerged that successful reproduction rates tended to be highest.
By conducting the experiment with different ratios of phenotypes, Stefan was able to show that the two behavior types could efficiently co-exist within a single population, with the stable ratio being 25 percent Foragers to 75 percent Trackers.
"In this experiment, our robots were hermaphrodites, all robots mate and can produce offspring," said Dr. Elfwing. "In the next stage, we want to see if the robots will take on male and female roles, by taking different risks and costs in reproduction.”
Although modern jet airliners may be at the cutting edge of technology, assembling them is, in many ways, still as much of a craft as 18th century shipbuilding, requiring loads of skill and manual labor to get the job done. The Fraunhofer Institute for Machine Tools and Forming Technology (IWU) in Chemnitz, Germany wants to bring airplane construction into the 21st century with a snake-like robot that can assemble airplane wings by reaching into narrow, hard to reach cavities.
Airplane manufacturer Airbus expects to see air traffic triple by 2030, with major airports handling close to half a million passengers a day and Fraunhofer says that current aircraft construction methods will have difficulty keeping up with the demand for new planes. One answer is to automate assembly, but wings pose some tricky problems that most industrial robots can’t handle because they’re too inflexible and their reach is too short to extend the up to five meters (16 ft) required inside the wings.
Modern wings aren't just metal planks sticking out of a fuselage. They’re a complex collection of fuel tanks, hydraulics, power cables, engine supports, ailerons, flaps, ribs, struts, spars, and stringers. This results in all manner of small, hollow chambers that workers need to get into to drill holes, attach bolts, and seal joints.
Needless to say, it’s extremely slow, hard work that has to be done in the presence of solvent fumes. Look in a modern airplane assembly or maintenance manual and you’ll find detailed instructions for workers on how to wiggle into a crawl space and reach a widget. As a result, major airliner manufacturers are leading employers of little people, who are hired to work in confined spaces, such as wings.
The Fraunhofer approach was to come up with a 60 kg (132 lb) robot with an arm that resembles an automated snake. It’s built in eight articulated sections with a total length of 2.5 m (8.2 ft), weight of 15 kg (33 lb), and ending in a hand or inspection camera. According to Fraunhofer, the key to the snake-like robot is a patented gear system with motors generating 500 Nm of torque integrated into each of the arm’s eight sections. These, combined with a cord-and-spindle drive system, allow each section to turn independently up to 90 degrees.
"The robot is equipped with articulated arms consisting of eight series-connected elements which allow them to be rotated or inclined within a very narrow radius in order to reach the furthest extremities of the wingbox cavities," says IWU project manager Marco Breitfeld. "That’s why we often refer to the system as a snake robot.”
Currently, the robot is undergoing mechanical design and testing and will be displayed at the Automatica trade show in Munich from June 3 to 6. The next stage in the project involves installing the robot on a mobile platform or rails, allowing it to travel along the length of the wing while working. Fraunhofer says that a full-scale version of the robot should be ready by the end of the year.
Festo's SmartBird robotic seagull is barely four months old, but already it's flown (or we should probably assume, been flown) from Germany to Edinburgh for the 2011 TEDGlobal conference. Festo's Markus Fischer, theSmartBird project leader, presented a short talk about SmartBird, along with a couple live demonstrations of the robot, complete with a few friendly dive-bombings:

If you're looking for another TEDTalk to wile away your Monday with, allow me to recommend Kevin Slavin's fascinating presentation on how algorithms are shaping our world, which uses some vacuuming robot pics that you might recognize to illustrate how abstract programming can have tangible effects on our daily lives.

Every year, Festo comes up with innovative and fantastical new robot designsas part of its "Bionic Learning Network," which seeks to use "principles from nature to provide inspiration for technical applications." In practice, this means developing all kinds of spectacular robotic animals, including thisabsolutely amazing flying seagull.

Festo's Newest Robot Is a Hopping Bionic Kangaroo


Photo: Festo
Every year, Festo comes up with innovative and fantastical new robot designsas part of its "Bionic Learning Network," which seeks to use "principles from nature to provide inspiration for technical applications." In practice, this means developing all kinds of spectacular robotic animals, including thisabsolutely amazing flying seagull.
For the last few years, Festo has been secretly working in their sprawling German laboratory lair on their most ambitious bioinspired robot yet: an unstoppable (we assume) hopping robotic kangaroo.
BionicKangaroo is able to realistically emulate the jumping behavior of real kangaroos, which means that it can efficiently recover energy from one jump to help it make another jump. Without this capability, kangaroos (real ones) would get very very tired very very quickly, but by using their tendons like elastic springs, the animals can bound at high speeds efficiently for substantial periods of time.
BionicKangaroo emulates this with an actual elastic spring, which partially "charges" the legs on landing. The entire robotic animal weighs just 7 kilograms and stands a meter high, but it can jump 0.4 meter vertically and 0.8 meters horizontally, which is fairly impressive.
Of course, an internal power source is necessary as well, and BionicKangaroo relies on either a small compressor or a storage tank to provide high pressure air for the pneumatic muscles that power the jumping. Lightweight batteries drive everything, and a sophisticated kinematic control system keep the robot from toppling over. Control, as you might have noticed in the video, is gesture-based, via a Thalmic Labs Myo armband.
Festo sent us a neat graphic of how everything is laid out, along with a step-by-step description of the jump sequence:
The take-off and flight phase
Before the first jump, the elastic tendon is pneumatically pre-tensioned. The BionicKangaroo shifts its centre of gravity forwards and starts to tilt. As soon as a defined angle is reached at a corresponding angular velocity, the pneumatic cylinders are activated, the energy from the tendon is released and the kangaroo takes off.
In order to jump as far as possible, the kangaroo pulls its legs forward during the flight phase. This creates torque at the hip, for which the artificial animal compensates with a movement of its tail. The top of the body thereby stays almost horizontal.
The landing phase: energy for the next jump
Upon landing, the tendon is tensioned again, thus converting the kinetic energy of the previous jump to potential energy. The energy is thereby stored in the system and can be called on for the second jump. The landing phase is the critical process for recovering the energy and is responsible for the kangaroo’s efficient jumping behaviour. During this phase the tail moves towards the ground and thus back to its starting position.
Reduced energy consumption in the following jumps
If the kangaroo continues jumping, it channels the stored energy directly into the next jump. The potential energy from the elastic tendon is used again at this point. The valves switch at the right moment and the next jump begins. In this way it takes several jumps one after the other.
If the BionicKangaroo is supposed to come to a standstill, it must absorb as much energy as possible. To do so, the pneumatic actuators are switched accordingly and the tendon is actively tensioned again.
As far as we know, Festo is not intending to unleash an invasion of robotic kangaroos (as fantastic as that would be). Rather, they're exploring ways of intelligently recovering energy in industrial automation, and combining electronics with pneumatics in new ways.
At this point, we're scientifically obligated to point out that it might be more accurate to call this robot a wallaby rather than a kangaroo. Both wallabies and kangaroos are members of the same family (Macropodidae), but the generally accepted differentiator between the two is that wallabies are, well, smaller. And that's about it. So considering that this little fellow is on the diminutive side (at least, compared to a kangaroo, which can kick you in the face), we're going to suggest to Festo that BionicWallaby might be a bit more accurate.
The new robot will be officially unveiled next week at Hannover Messe.
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Ok, so you know nothing about robotics huh? Well, you’ve come to the
right place. Unfortunately there are lots of people like you out there.
Robotics isn’t an easy hobby, and there really isn’t a whole lot of
information out there, especially compared to other hobbies. But, with
a little diligence and hard work, you’ll be up and running in no time.
Below are 10 hints and tips to getting started. Hopefully they’ll help
you avoid some common mistakes.
1. Learn about electronics: While this isn’t one
of the most fun parts about robotics, it is essential. For a while I
lived under the impression that I could do robotics without knowing
anything about electronics. But, I found out that I was wrong pretty
soon. Don’t get me wrong, you don’t have to have an EE degree, but you
do need to know some of the basics. Getting Started In Electronics by Forrest Mimms is an excellent resource for this. You can find a review of this book
here.
There’s also a helpful online electronics tutorial here.
2. Buy some books: In order to have a good start into
robotics, you will need to start growing your library right off the bat.
Getting the right books will provide an invaluable help. Robot Building for Beginners is a good starting point. An absolute must-have book is Robot Builder’s Bonanza. You’ll also want to get some magazine subscriptions. Robot Magazine is great for beginners, along with Servo Magazine. You’ll also find other interesting books, on our books page.
3. Start off small:
This is probably one most important points of this whole article. Stay
small! Resist the urge to let your mind run wild with possiblities of
cooking robot that will dust and vacuum at the same time. You need to
start off small. Try putting some motors onto a base (like some AOL CDs or a bread-board from Radio Shack or Jameco) and running them with a Basic Stamp or an OOPic.
If you’re more the kit type, you will find an impressive selection at RobotShop, Lynxmotion, Parallax, Rogue Robotics and Budget Robotics. If you don’t have any electronics or mechanics experience
I’d recommend getting a kit.
4. Get LEGO Mindstorms if you don’t have any programming experience:
If you’ve never programmed before, you’re in a bit of trouble, because
you’ll have to learn in order to do robotics, well, mostly. However,
LEGO Mindstorms offers
and excellent resource for the totally illiterate. I have never heard
anything bad about this product, and HIGHLY recommend it. Plus, if you
advance beyond it’s capabilites, there are tons of great websites and
books about hacking it for other uses. You can buy the Mindstorms 2.0 kit here, or wait till Aug. 2006 to get the new version, Mindstorms NXT. VEX Robotics Kit is also a good starting point. I don’t have any person experience with it, but I’ve heard good things.
5. Enter a contest – I.E. Build a ‘bot to do something:
After you’re initial robot or so, you’ll need to start to plan
for a robot that will actually do something. Part of the problem for a
lot of people is that they
never plan their robot ahead of time. When you have definite goals in
mind, i.e. “I want my robot to patrol the house at night”, you are much
more motovated and interested in finishing. A great way to do this is
to enter your robot into a contest. Mini Sumo, and the international Fire-Fighting Contest are excellent choices. Many clubs have annual contests and events.
6. Work regularly on your ‘bots:
Make yourself work on your robots regularly, especially if you’re
entering a contest! Coming back to a project after weeks of ingnoring
it is tough. Take that time to think about the project
and plan. It will help, even if it’s just for a few minutes before bed. Also, keep a regular journal of what you’ve done. Documenting your work is important.
7. Read about mistakes of others: Take a look at our top mistakes with building a robot list and know what to avoid.
8. Don’t be a tightwad:
This is probably the second most important point in this article. Take
it from one – Being a tightwad, or cheap person, isn’t good. You may
save a few dollars, but you will loose so much more with the extra time
and frustration involved in being cheap. Don’t get me wrong, you should
always look for bargans, but if that involves desoldering components
off of circuit boards, as opposed to spending $5 at Digi-Key,
just give up. I’ve learned this lesson the hard way. Robotics isn’t a
cheap hobby, and sometime you’ll have to face the facts. You’re time
and sanity are worth more.
9. Ask LOTS of questions: Subscribe to every
e-mail list and newsgroup that you can find, and just ask questions.
You’ll learn more that way than from any book or website. Questions are
never stupid. Don’t be shy. No one ever gets good enough where they
don’t have to ask questions sometime. The forums at Robot Magazine are a good place to start.
10. Share you’re experinces with others: Don’t
make the rest of the world learn everything the hard way. That’s the
beauty of the internet and e-mail. If you’re figured something out,
write and article or e-mail. Let others know. Sheesh, that’s the reason
you’re reading this right now, I’m letting you know how to do things
the right way.
Last year Dartmouth made headlines around the globe for a tiny innovation: the world’s smallest untethered mobile robot. A joint project between Dartmouth computer scientists and Thayer School engineers, the microrobot was created in the microengineering lab in Cummings Hall. We asked microengineering lab director Professor Christopher Levey, co-PI and lead creator of the breakthrough robot’s electromechanical design and fabrication, to tell us how he and his colleagues took microrobots to a whole new level.

Just how small is this robot?

The entire robot is under 10 micrometers thick — one-tenth the thickness of a human hair — and consists of a locomotion drive that is 60 micrometers by 120 micrometers and a steering arm that is 8 micrometers by 130 micrometers. When placed on a penny and viewed through a microscope it looks like a hair on Lincoln’s chin.

What is the significance of this being an untethered mobile robot?

Whereas earlier mobile devices this size were powered via wires or rails, our robot moves freely on its surface. It is the tiniest robot without tethers that is engaged in its own locomotion and steering. Power and instructions are broadcast from a grid of electrodes buried under the surface it walks on — there is no direct electrical contact.

How does the robot move?

The robot contains two independent actuators — the “scratch drive” for forward locomotion and the steering arm for turning. The scratch drive moves like an inchworm, moving forward an average of 10 nanometers each step. We have demonstrated this motion for more than 40 million such steps with no sign of fatigue, covering a distance of about one foot over the course of half an hour. If a person took that many steps, she would travel halfway around the world. The robot turns by snapping down a paddle on the end of its steering arm, then pivoting around it. An operator can control forward motion and turning with a sequence of commands through the wireless transmission that also powers the motion.

How did this idea come to you?

About eight years ago, I was having a discussion with Bruce Donald and Daniela Rus, both computer science professors at Dartmouth at the time (Bruce is now at Duke, and Daniela is at MIT), about their work involving large-scale (brick-sized) self-reconfiguring robots. We started thinking about how to develop similar robot modules but on a much, much smaller scale. Such robots would have several advantages: they would be on the right scale to interact with other very small things and we could make large numbers of them at very low cost by using the microfabrication techniques first developed for the microelectronics industry. The complex interactions of thousands of robots could lead to effects that are qualitatively very different from those of just a few robots, in the same way that the behavior of a computer is much richer than that of a few switches.

What kind of collaboration went into the creation of this robot?

Micromachining research spans a broad range of disciplines, including electrical, mechanical, and chemical engineering, physics, materials science, computer science, and robotics. The success of this microrobot is a reflection of Thayer’s non-departmental focus and a strong interdisciplinary collaboration that spanned across Dartmouth. It started with the brainstorming session I had with Bruce Donald and Daniela Rus and grew to include many others, particularly recent computer science doctoral student Craig McGray Adv’05 and current doctoral candidate Igor Paprotny, who did most of the work. Thayer School Professors Ursula Gibson ’76 and Francis Kennedy and Ellen Pettigrew ’08, an intern with Dartmouth’s Women in Science Project, also helped.
TIDY WORK: Levey and his colleagues worked on the minuscule robot in Thayer School’s microengineering lab.TIDY WORK: Levey and his colleagues worked on the minuscule robot in Thayer School’s microengineering lab.

What challenges did your team face and how did you overcome them?

Given the minute size of the robot and the delicate environment in which it operates, we faced many challenges. The broadest was how to pack the functionality of locomotion, steering, memory, power delivery, and reception and decoding of control commands into this small a package. We met this challenge by keeping it simple; the entire robot is a single piece of silicon. There are no parts to assemble and no batteries or microprocessors to wire up. Memory is stored in a simple spring-loaded electromechanical switch, the steering arm, which also serves mechanically to make the robot turn.
We also needed to develop a surface environment that would supply power to the robot without using wires, tracks, springs, or other physical connectors. I came up with the idea of using a grid of interdigitated electrodes buried in an insulator to induce a charge polarization in the robot and a resulting vertical force. The scratch-drive mechanism then translates this force into lateral locomotion. After considerable effort by the graduate students in the Thayer microengineering lab fabricating this environment, we found that this scheme works well. It is a “one-wire” system, that is, there is a single signal wire plus one ground wire attached to the environment. All commands are also sent on the signal wire, and distributed uniformly over the environmental surface, to be decoded by the robot.
Another challenge was how to address various steering arms and scratch drives individually. Our analysis showed that we could not do this using the standard microfabrication techniques, which allow a designer control of only in-plane shapes; we needed to curl our devices up out of the plane. We took advantage of a previous Thayer microengineering lab invention to do this: Stress Engineered Micro-Structures (SEMS). Engineers working on micromachines typically try to minimize stress gradients in their materials so objects won’t curl. In previous work with former Thayer School Professor Al Henning ’77 Adv’79 and graduate student Chia-Lun Tsai Th’98, we controlled stress gradients to create usefully curved micromachine parts. The trick is to add a “stressor” layer under tension to the top of the device and to control the extent of the resulting curl through in-plane patterning of the size of the stressor. We now use this SEMS technique to add just the desired curl to our robot steering arms, and hence to allow control of individual arms: Arms curled a long way from the base are thereby programmed to respond only to high signal voltages; arms with little curl will snap down in response to lower voltages.
An obstacle we needed to overcome was that of charging. We found that the scratch drive built up an electrostatic charge, causing it to occasionally stick to the surface. We got around this by alternating positive and negative charges. If the environment charges up positively, a fraction of a second later we switch to a negative waveform to reverse that process. We keep reversing the polarity in order to avoid building up any one charge. The robot responds equally to either polarity.

What is the most significant feat you accomplished in creating this microrobot?

Moving robots this size anywhere we want in two dimensions is a tremendous accomplishment. We managed to free scratch drives from rails and tethers and then added a tiny silicon paddle (coated on the upside with chromium — the SEMS stressor layer) so the robot can turn on command. We can control the paddle’s motion separately from the scratch drive; the paddle responds to higher voltage levels. And by varying the size and shape of the paddle, we can create robots that respond to various voltages.
- See more at: http://engineering.dartmouth.edu/magazine/the-worlds-smallest-untethered-robot/#sthash.ql2TvSaN.dpuf

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