Hizook

Perhaps the ultimate in wearable computing and humanoid robots is an exoskeleton. If you recall, I was privaledged to watch a talk given by Stephen Jacobsen of Sarcos at the Wearables conference. I tried finding copies of the images and videos he showed, but at the time, they were closely guarded... Well, now Engadget has posted similar to the ones Mr. Jacobsen showed us a few months ago...

So here is a picture, followed by a video (local copy here).

I'd like to make a quick note about the Georgia Tech DARPA Urban Grand Challenge team, Sting Racing.  Unfortunately, they did not qualify for the finals, do the dismay of all of us who do not get to watch the competition live.

You can learn more about the failure of the robot on the team's blog, but essentially,

In our Saturday afternoon test in Area A Sting 1 crashed head-on into a concrete barrier. The front sensor mount was bent severely and pushed into the front of the vehicle. Fortunately the protection offered by the design and strength of the sensor mount saved the sensors.

After assessing the log data we determined the cause of the accident was a failure in the communication link between our GPS/IMU and the main control computer. Without “pose” information the robot could not know that it was moving.

If you're in to robot carnage, you can watch the video below.

OK, time to get back to work. 

UPDATE 11/29/2007:  I found a copy of a poster that went to RSS-2007 for this project here (local copy here).  

During the Spring 2007 semester, several friends (and labmates) took a course at GA Tech on mobile manipulation. This was no ordinary class... they used a Segway base with KUKA arm to fetch a cup of coffee!

There are a ton of reasons that this is interesting, from mobility, navigation, manipulation, etc. However, the most impressive thing is that each group used different software to complete the task. If memory serves, one used MS Robotics Studio, another used Player/Stage on Linux, and another used a functional language called OCaml on Mac (right?). Some probably question whether or not it works, well it does! And here is the video proof. From Henrik's blog,

The exam/demonstration for 4632B on mobile manipulation took place today. One group did 3 complete cycles of coffee delivery, the two other groups did partial cycles. The system is composed of a Segway RMP200 with a KUKA KR-5 sixx arm mounted on top. The strategies demonstrated included - particle based object localization, MC localization, visual servoing (image and 3D based).

I'm really pissed that I didn't take this class. I didn't even know it was being offered, and they ended up working on it about 30 feet from my desk.

UPDATE 10/23/2007: I managed to acquire the videos (see this post).  You can find the higher-resolution, permanent videos here, here, and here.

UPDATE 10/22/2007: I found two of the videos on YouTube, thus I have permanent copies of those two here and here. I'm still trying to figure out a way to obtain the other 1 (and some of the other ones from that site for future posts).

Festo makes some pretty awesome automation equipment. Besides "typical" engineering work, they apparently do some fun research applications. Today I'm going to show their robotic dirigible and submersible manta rays. Before discussing the details, take a look at their life-like movements!

The dirigible is my personal favorite (namely because it doesn't require scuba gear to observe), but both look very graceful. I can just imagine what it might be like on an alien world watching light-weight aerial "manta rays" swimming in the sky -- it would be amazing!

Air_ray, modelled on the manta ray, is a remote-controlled hybrid construction consisting of a helium-filled ballonet and a beating wing drive. Its light design makes it possible for it to “swim” in the sea of air, boosted by helium, in a similar way to the manta ray in water.

Propulsion is achieved by a beating wing drive. The servo drive-controlled wing, which can move up and down, utilises the Fin Ray Effect® and is based on alternate pulling and pushing flanks connected via frames. When pressure is exerted on one flank, the geometrical structure curves automatically against the direction of the influencing force. A servo drive pulls the two flanks alternately in the longitudinal direction, thus moving the wing up and down.

Aqua_ray is a remote-controlled fish driven by water hydraulics, the shape and movements of which have been based on the model of a manta ray.

The central drive and control unit of Aqua_ray takes the form of a Festo Fluidic Muscle. This is combined with the Fin Ray Effect®, a design based on the functional anatomy of a fish’s fin that makes it possible to imitate the fin drive of the natural role model almost perfectly.

As the Aqua_ray can be manoeuvred extremely well, and can be operated both as a hydrostatic glider and with an active wing beat, substantial energy savings can be achieved. Thanks to its shape and method of movement, the Aqua_ray can be used in wide ranging areas of oceanography, without disrupting the natural environment.

Remember all the robots at RoboCup 2007 that used holonomic (omnidirectional) wheels? Well, there were quite a few; however, they were all rather small (none larger than a few kilograms). Anyway, check this out!

These large omnidirectional wheels are made my AirTrax, where they are equipped on fork-lifts, lifts, and other equipment transporters.

They even have a video of them in action via YouTube, or another here (local copy)

The wheels are definitely cool, but I don't think they're going to be the "huge revolution" AirTrax thinks they will... (I mean seriously, even pre-teens built and used them on their RoboCup robots.)

I would be curious to learn what a set of AirTrax omni-wheels would cost (I'm sure you could machine 3-to-4 of them fairly cheap, especially if you cast your own rollers). These would be great for indoor mobile robots; the control is much more elegant than differential drive.

Does everyone remember Boston Dynamics' Big Dog walking robot?

Well, as a quick refresh: 

BigDog is powered by a gasoline engine that drives a hydraulic actuation system. BigDog's legs are articulated like an animal’s, and have compliant elements that absorb shock and recycle energy from one step to the next. BigDog is the size of a large dog or small mule, measuring 1 meter long, 0.7 meters tall and 75 kg weight.

BigDog has an on-board computer that controls locomotion, servos the legs and handles a wide variety of sensors. BigDog’s control system manages the dynamics of its behavior to keep it balanced, steer, navigate, and regulate energetics as conditions vary. Sensors for locomotion include joint position, joint force, ground contact, ground load, a laser gyroscope, and a stereo vision system. Other sensors focus on the internal state of BigDog, monitoring the hydraulic pressure, oil temperature, engine temperature, rpm, battery charge and others.

So far, BigDog has trotted at 3.3 mph, climbed a 35 degree slope and carried a 120 lb load.

Big Dog could take a solid kick and still remain upright! It is probably one of the most impressive walking/running robots to date.  (See YouTube video below, or a different version from Boston Dynamics -- local copy)

Well, Popular Mechanics showed pictures of Little Dog (Big Dog's baby brother) from DARPA Tech 2007.

I had never heard of Little Dog, and was about to be all impressed until I read that...

Little Dog will never be as famous as its sibling, Big Dog. Why? It can't recover from a kick, and whereas Big Dog hops along at a jaunty sprint, the toy-size Little Dog takes careful, measured steps. That's because it's practically blind. It has no onboard sensors, and relies on cameras set up around the lab to guide it. Data from these infrared and visible cameras is turned into a motion-capture file, which is beamed wirelessly to the robot. Reflective markers lining the track and dotting the robot help the cameras correlate its position in relation to its environment (similar to the motion-capture suits actors wear during videogame development or visual effects scenes).

It's hard to come up with an accurate comparison, but Little Dog is essentially blindfolded, but following external advice. Currently, it's allowed a gradual, "stop-and-start" approach to navigating uneven terrain, but by the time the Learning Locomotion program ends in January 2009, Little Dog will be practically scrambling. The research will likely be used to improve Big Dog specifically, and walking robots in general, since data related to Little Dog and its environment can be scaled up to larger obstacles and roughly human-size limbs. So as quaint as it looked poking its way down an eight-foot stretch, what we learn from Little Dog could help every robot with legs a little more sure-footed.

Oh well, still pretty cool.  I'm betting it could still move faster than an Aibo...

This is Sting 1, Georgia Tech's entry into the DARPA Grand Challenge.  The goal is to create an autonomous robotic vehicle that can brave America's insane city streets.  Anyway, I just found out today that Tech has officially made it in to the final round of competition.  Congratulations guys!  

I really wish I could say that I am a part of the team, but I just don't have the time right now to work on another project...

It is a very impressive piece of machinery!  In case you can't tell, that is a Porsche Cayenne modified for autonomous (or remote-conrol) operation.  The car uses myriad sensors (including laser range finders, radar, GPS, and IMUs).  It is all controlled by 16 (yes, sixteen) processors -- in the form of 8 dual-Pentiums -- running Ubuntu Linux.  Now that is impressive! 

From the team's official website: 

Sting Racing selected a Porsche Cayenne, designated Sting 1, as the base vehicle for its entry in the Urban Design Challenge. The high-end SUV comes from the factory with a significant degree of automation and computer control already built in. Most of the primary and secondary controls can be accessed through the factory-installed, integrated CAN network. In addition, its standard air-conditioning package is adequate to cool the computers that areinstalled on board to operate the vehicle.

Sting 1 has been retrofitted for complete computer control of steering, throttle and brakes as well as secondary systems such as lights and windshield wipers. The retrofit was performed by EMC.

The vehicle is controlled by eight dual Pentium computers installed in the trunk space and thye are all running Ubuntu Linux.

For navigation, tracking other vehicles and situation assessment, the car is equipped with Novatel GPS sensors, an inertial package (IMU), six cameras, six laser scanners (Riegl & SICK LMS) and three 22 GHz radar units (EATON).

Sting 1 conforms to Challenge vehicle requirements:

• SUV-size vehicle, preferably stock (Porsche Cayennem, 2006 model)
• Meets California emission standards
• Weighs between 2,000 and 30,000 pounds
• Fully autonomous operation
• Equipped with warning light, audible alarm, blinkers and brake lights

Sting 1 meets Challenge performance requirements:

• Maximum speed of 30 mph
• Capable of emergency stops within 20 m
• Maintains a 1-5 m distance from other vehicles
• Stops within 1 meter of stop signs and street crossing lines

In addition, during testing and in preparation for the the race the vehicle chase car equipped with a manually operated pause and stop system that can be engaged in case of emergency.

I personally know a number of people working on this project, and I think they have a real shot at winning.  I think that would be great for Georgia Tech and our new robotics PhD, of which I'm (almost) officially a part.  Go Tech!

I've been doing a lot of searches for literature and examples of small, "micro" robots. First, let's clarify what constitutes a "micro" robot, as there are a number of competing definitions (for example, the 1 in³ robots from the RoboGames are called "nano" robots, yet clearly they are not at the nano scale). In general, I prefer the following definitions, as they seem to follow common sense.

Thus the general size I was searching for was between 1 cm³ and 64 cm³ in total volume, or between 1 cm and 4 cm per dimension (the smaller, the better). I'd like to share what I've found and later ask for some help. Let's take a look at some great examples!

First up is Pico, which hit the blogosphere earlier this year. While the builder falsely believes his is the "world's smallest robot," it is impressive for a home-brew bot!

The robot measures in at 2cm³ (12.5mm per side), and features a laser-cut chassis and two Didel motors (MK04S-24 driving worm gears). With a run-time of 15 minutes off a 10mAh Li-Poly battery (approx 3.7V), that equates to a power consumption of about 140 mW. I suppose the large power consumption is to be expected, given that his Didel motors can use as much as 100mA at 3V! I'm still impressed. Given that these sort of webpages have a tendency to disappear, I have archived a copy of the page here. He even has a video (local copy here).

Another effort comes from the Ecole Polytechnique Federale De Lausanne (EPFL, a University in France), where they have developed a series of micro-robots. The builders of these robots actually went on to found Didel, where the motors from Pico originated. Unfortunately, the robots lack (in general) detailed technical specifications. Either way, they are very aesthetically pleasing and have phenomenal mechanical designs (with custom-machined gears). For example, here is one of them that measures 1 cm³.

This robot has been built by André Guignard and programmed by Olivier Matthey.

It uses two smoovy 3mm motors from RMB. A first gear transmits the movement to the wheels, made of the second gear level. The initial design was using a rubber caterpillar, but its efficiency was too weak. The robot does not fit any more into one cubic centimeter. We have to find better ideas for the next generation.

A PIC 16C54 drives directly the motors. Two photo-transistors and one LED have been bonded on the side in order to follow a wall. This is not yet operating well; the ambient light is too strong compared to the LED power.

Another one from the same university is Jemmy, also 1 cm³.

• Driven by two synchronous 3 mmØ RMB smoovy motors.
• Four passive infrared sensors.
• Embedded PIC microcontroller, which generates the 3-phase signals for both motors, performs time-to-voltage conversion to read the sensors, and communicates using a single-wire bidirectional link with an optional supervision unit. To speed up software development, all variables of the embedded processor can be read/written through this communication channel.
• Precision gearing, 8 miniature ball bearings
• This robot was the winner of the International Microrobot Maze Contest '97, Nagoya (Japan) in the 1 cm3 category.

Curiously, it appears (though I have no confirmation) that both of the 1 cm³ robots from EPFL are tethered for power. However, their 1 in³ robot Inchy is not.

• Three rechargeable Leclanché Ni-MH button cells provide an autonomy of 15 to 30 minutes.
• Two synchronous 5 mmØ RMB smoovy motors, with which speeds of over 30 cm/s can be achieved.
• Four infrared proximity sensors, which can be replaced by other devices simply by exchanging the removable top PCB.
• The microcontroller performs the same tasks as in Jemmy. Furthermore, it is located on a removable PCB (at the bottom) and also can be reprogrammed in-circuit within seconds by attaching our programmer to the 5-pin connector visible on the top.

Perhaps the most promising robot to come out of EPFL is Alice, a 8 cm³ (2 cm per side) robot.

By herself, Alice isn't all that interesting (it's not the smallest, and it doesn't have the most functionality). But the vast number of publications that document Alice's construction and place in the micro-robot space are invaluable.

• "Autonomous Micro-Robots: Applications and Limitations" (local copy)
• "Mobile Micro-Robots Ready to Us: Alice" (local copy)
• "Fascination of Down Scaling -- Alice the Sugar Cube Robot" (local copy)

Alice also boasts an impressively low power consumption!

Dimensions: 22mm x 21mm x 20mm
Velocity: 40 mm/s
Power consumption: 12 - 17 mW
Communication: local IR 6 cm, IR & radio 10 m
Power autonomy: up to 10 hours

The low power consumption is largely determined by the very-low-power SWATCH wristwatch motors. Based on the Alice 2004 Poster (local copy), it appears that they even sell/sold some of the Alice robots to research institutions for $500 SFr (about $415 USD) each. There are also a number of expansion modules for Alice, such as solar power, camera, radio, gripper, and off-road traction.

One awesome use of these robots is to study swarm/collective behavior. Check out this cool video (local copy) showing a swarm of 90 Alices acting simultaneously.

Another micro-robot was developed by Sandia National Laboratories. Measuring in at 4 cm³ (0.25 in³), it was an impressive feat when it was first announced, given its size, untethered power, autonomous operation, and sensor suite (which included chemical sensors). Its drive train is also visually appealing. Below are some pictures and a video (copy).

Finally, let's not forget the Epson EMRoS series of micro robots, which made it into the Guinness Book of Records.

The Monsieur II-P prototype microrobot represents a step up from the earlier generation of EMRoS series microrobots. Not only does it run longer and faster than its predecessors, but it can also be flexibly controlled. The enabling technologies? An ultra-thin, ultrasonic motor and a low-power Bluetooth module, both products of Epson's R&D lab.

There were four members of the EMRoS family: Monsieur (1 cm³ in volume and listed by the Guinness Book of Records; 1993 ), Niño (0.5 cm³ in volume; 1994); Ricordo (1 cm³ in volume and equipped with a recording and playback function; 1995); and Rubie (a 1 cm³ microrobot equipped with capricious wandering function;1995). All are autonomous traveling robots that chase a light source. Sales of the EMRoS series have been discontinued.

That's a bummer that they were discontinued. The specifications were pretty impressive -- they included bluetooth control?!?

Prototype Microrobot "Monsieur II-P" Features: An ultrathin, ultrasonic motor enables the left and right wheels to be independently controlled, allowing the microrobot to be driven forward and backwards, as well as perform pirouettes. A Bluetooth module enables multiple units to be controlled simultaneously. (1) Power supply: Three air-zinc battery (1.4 V) connected in series (2) Running time: 5 hours (3) Traveling speed: Approx. 70 mm/s (controlled) Approx. 150 mm/s (not controlled) (4) Operating voltage: 2.0 V (CPU & Bluetooth module) 2.2 V (ultrasonic motor) (5) Weight: Approx. 12.5 g (total weight) Approx. 5.5 g (internal parts, including ultrasonic motor) Approx. 4.3 g (three battery cells) Approx. 2.5 g (housing) (6) Volume: Approx. 7.8 cc (excluding projecting parts) * Monsieur II-P is a prototype only. There are no plans to market it as a commercial product.

Of course, let us not forget the MIT Ants, which measured in at a hefty 38.5 cm³. I suppose the "bulk" is forgivable, given the plethora of sensors...

Width (Excluding whiskers): 1.4 inch
Legnth (Excluding whiskers): 1.4 inch
Height: 1.2 inch
Weight: 1.18 oz

Total Battery Voltage: 2.4 volts
Batery Type: Varta VT110 1.2v NiCd cells
Bettery Life: 20min

Motor Stall Torque: .5 oz/inch
Wheel Radius: .25 inch
Max Speed: .5 ft/sec
Gear Ratio: 59:1

CPU: Motorola M68HC11E9 in the TQFP package
Clock Speed: 2Mhz
Memory: Xicor X68C75 8k EEPROM

4 Infrared Receivers
4 Light Sensors
2 Bump Sensors
5 Food Sensors
1 Tilt Sensor
2 Mandible Position Sensors
1 Battery Voltage Sensor

1 IR Beacon Emitter
1 IR Tag Emitter
3 Mood LEDs

Anyway, this is by no means a comprehensive coverage of past and present micro-robots. This CMU page (when it works) lists a number of other micro-robot platforms.

Since I'm fairly interested in these micro-robots, I've been thinking about building some of my own. I've been searching for good motors, gears, and other mechanical components. However, so far only Didel and Smoovy motors seem to be available (recall that their power was an order-of-magnitude worse than the wristwatch-based motors). Does anyone have any insight on wristwatch motors, such as suppliers and models? I'll probably make a separate post later about micro robot components (motors, chassis, sensors) and electrical design (microcontroller, wireless bootloaders, etc)...

By the way, I enjoyed the "Transformers" movie too...

Well, among other things I spent my Independence Day volunteering at RoboCup 2007. After I finished volunteering, the girlfriend and I wandered around and took a bunch of pictures and videos from the event. We'd like to share them with you. This is a sort of continuation from my previous RoboCup 2007 post. As a side note, I am very proud that the previous post made Engadget! They've had a subsequent post that features a link to the RoboCup 2007 Flickr pool. Here you can find a ton of additional pictures from others (including Dr. Balch, a robotics professor at GA Tech).

First, I'd like to recant my statement about the humanoids soccer competition. While they may be a little slower and more cumbersome, they are a blast to watch during actual competition. Just check out the videos (goal, action, and practicing).

We had the opportunity to watch the 4-legged (Aibo) soccer league. These were a blast to watch, but we were somewhat disappointed with the mechanics... Everyone used purchased 4-legged Aibos rather than custom-designed robots. Does anyone know if this is a requirement, or just done for simplicity? Oh well, they are fun to watch. Check out the pictures and videos.

Overview of the 4-Legged League arena.

Aibo goalie reacting to a shot.

A line of Aibo robots sitting in the prep area. In total, this is probably the largest gathering of the discontinued Aibos I've ever seen! There must be almost 100 of them hanging around. It is quite a site to behold.

Aibo takes a shot and scores a goal. [video]

Aibo takes a shot. It's blocked by the goalie. The follow-up shot hits the goal-post and misses to the right. Close! [video]

Aibo takes a shot that is blocked by the goalie. The attacking Aibo's follow-up pays off with a goal! [video]

Aibo scores a goal against its human controller during practice. [video]

We had the chance to catch some more of the Middle-Size League robots. I still say these are the most entertaining and technically challenging, but that is just my bias. Below is a picture of a team working on their robots in the pits.

In the match we watched, one team was having major technical difficulties. Effectively, only a single one of their robots was functioning properly. However, that didn't stop them -- the 1-robot team managed to score a goal against their opponents! I'd rename that bot "Ronaldo!" [video]

Ultimately even Ronaldo suffered from technical glitches, and the opposition capitalized by scoring several "easy" goals. [video]

I finally got a close-up of some of the Small-Size League robots (that use the overhead camera). It turns out I was incorrect on my previous post -- most of them do use holonomic wheels. I'm amazed at how quickly they move with those wheels. There weren't any games playing while I was there, but I snagged a few pictures. Note the color codes on the top for recognition.

There is also a "Search and Rescue" event (basically, teleoperated all-terrain robots) at RoboCup, though I'm not sure I understand how it is related to soccer. If they're indiscriminately going to add events, I'd like to see robot-sumo and tetsujin (robot exo-skeletons) added. Both are present at RoboGames. Anyway, here are a few Search and Rescue robots, including the team from GA Tech.

Well, I suppose that about sums up my newest pictures and videos. I have also saved the full-res videos on my server for posterity. Again, I'd prefer you be gentle on my bandwidth by viewing the YouTube ones.

• Humanoid Goal
• Humanoid Match
• Humanoid Practice
• Aibo Goal
• Aibo Goal vs Human
• Aibo Goalie Block
• Aibo Goalie Block then Goal
• Mid-Size 1-Robot Team
• Mid-Size Goal

UPDATE: I've got a bunch of new pictures and videos from RoboCup 2007 posted. 

I was really bummed this summer when I missed the RoboGames. However, I consciously made the decision not to go since the RoboCup 2007 is in Atlanta this year, and is being held at my graduate school -- Georgia Tech! Because of this, I will be volunteering for several of the days, and I get up-close contact with the robot-builders, spectators, and event organizers.

Anyone with a Georgia Tech ID can get a spectator seat for free. If you're not so privileged, tickets can be had for like $10 (weekdays) or $20 (weekends). There are a TON of events this year (Small, Mid, and Junior soccer, Humanoid Soccer, 4-Legged Soccer, Nanogram, etc). It is being held across about 4 different venues (Campus Rec Center, Tech Square Research Building, Student Center, and Fox Theater), so there is plenty to watch. It is difficult to describe how large this event is, and how wonderful the caliber of robot-builders is (especially compared to other events I've attended, even compared to RoboGames). Just look at these shots of the "main" venue (Campus Rec Center).

From the front of the spectator area:

From the back of the spectator area:

There is literally always something cool going on, and the robot-builders are very friendly (from many different countries). For traditional roboticists, this is like heaven. I still miss some aspects of the RoboGames (like mini-Sumo); however, I don't really miss the BattleBots. The glorified RC cars usually don't appeal to traditional roboticists, but I'm sure that many enthusiasts would be disappointed by their absence.

Official competition just began today (Tuesday, July 3rd), but the event continues up through July 10th. I haven't seen any coverage on other blogs about RoboCup 2007, so I figured I'd share a selection of my pictures and videos (from team practice day -- yesterday on July 2nd).

This is a Junior Soccer League robot from Team Takahama. I had a chance to speak with this team at length, and I found their robot rather interesting. It uses 3 holonomic wheels for propulsion (like most of the robot soccer bots), it has a few wheels near the front that spin the ball to "hold" on to it. Then, it can shoot the ball using a little flipper on the front. I have a few videos of it in action here and here.

I personally favor the Junior Soccer League robots. A team for the Junior Soccer League only consists of two, small robots instead of the 4+ of other events. Also, the ball contains a number of infrared emitters, which makes detection simple as well. These factors make the Junior League much less costly, and thus more accessible to hobbyists. Many of the other events require large capital investments or sponsorship (to purchase 4-5 Aibos, or 4-5 laptops, etc).

Below is another Junior Soccer League robot, which uses compressed air to shoot the ball. Again, it employs holonomic wheels.

Below is an image of the Small Size League arena. You can see the cameras suspended above the arena. These are hooked to computers that perform visual recognition, tracking, and control of the robots to play soccer. This league focuses on multi-agent robotic cooperation and strategy.

I'm actually not a huge fan of the Small-Size league, mostly due to the external infrastructure and centralized control. Usually these robots do not use holonomic wheels, but rather use differential drive for speed and agility.

This is an image of a single robot from a Middle-Size League team. Notice the omnidirectional camera on the top. This is used in visual recognition algorithms to detect and track the ball. You can also see (under the number) a small laptop that controls this robot. Since each team is comprised of 4-5 robots, this can be quite expensive. Again, this robot uses holonomic wheels. The robots in this league are entirely autonomous, although the robots on each team are allowed to communicate wirelessly. They are pretty awesome. Check out the other pictures from this league below.

I also have a number of videos from the Middle-Size League robots practicing. Check them out here, here, and here.

Many people are enamored with the humanoid soccer. The humanoids' complexity is impressive, but their movements are still rather slow and cumbersome. Check out some of these videos for proof: vision tracking and goal.

There are still a number of events I have not explored. One event is the 4-legged soccer, which usually features teams of Sony Aibos playing soccer. Another event that I'm really looking forward to (since it is related to my research interests) is the Nanogram league. From the RoboCup website (including the image below),

The RoboCup Nanogram competition challenges teams of students and researchers to construct microscopic robots that will compete against each other in soccer-related agility drills. These robots will measure a few tens of micrometers to a few hundred micrometers in their largest dimension and will have masses ranging from a few nanograms to a few hundred nanograms.

The competitions over the next week are going to be really great. Hopefully I'll find time to share more of my pictures and videos, and hopefully I'll see you there!

I've kept local copies of the videos for posterity; however, I'd prefer if you'd view the YouTube videos listed above. The local copies can be found here:

• Team Takahama 1
• Team Takahama 2
• Middle-Size League Warmup Shot 1
• Middle-Size League Warmup Shot 2
• Middle-Size League Warmup Shot 3
• Humanoid Vision Tracking
• Humanoid Goal

Roland Piquepaille had an interesting write-up on an Israeli teams' efforts to create a miniature, inductive-powered robot to explore the inside of the human body (blood vessels in particular).

At first, I thought the above image was the actual prototype, in which case I would have been very impressed. Then, I read on...

You can see above "an artist's rendition of what the tiny submarine robot would look like." (Credit: Unknown, via the Jerusalem Post)

"Artist's rendition," indeed.

The researchers stress that the project is an "interesting development, but it has a long way to go before it is used in medicine." Solomon says that the tiny robot could be controlled for an unlimited amount of time to carry out any necessary medical procedure. The power source is an external magnetic field created near the patient that does not cause any harm to humans but supplies an endless supply of power for it to function. The robot's special structure enables it to move while being controlled by the operator using the magnetic field.

Yep, makes sense to use inductive/magnetic coupling for power, create the smallest such robot (that I know of), and claim great aspirations about fighting cancer and malignant tumors, but where is the functional prototype? "A long way to go," no doubt. I think there needs to be a little more substantiation when making such extreme claims. Publications are always good, as are active project websites.

Anyway, I've have seen a fair number of actual gastrointestinal robots for endoscopies (aka, "inside the human body") that use a similar idea. Most use peristaltic (undulating) motions to prevent tearing, lacerations, and punctures. However, some designs still use "gripping" feet mechanisms. One great example is a hybrid design from Carnegie Mellon (project homepage here and press release here). Most importantly, they are already performing testing in plastic tubing and pig intestines.

	This prototype shows a "six-legged" (actually, they apply pressure to the gastrointestinal tract walls) robot.
	This is another prototype (apparently 3-legged?) robot in an actual capsule.
	An overview of the CMU approach. Click on the image to enlarge.

Another great example comes from a New Scientist article entitled "Worm-inspired robot crawls through intestines." It features work performed by a multi-national European research team, and again, this research has produced working prototypes (with videos)!

	A prototype crawling through a pig intestine. Be sure to check out the video here.   (Local copy of the video here)
	A more recent prototype being held in a researcher's hand. Check out the video of the legs actuating here.   (Local copy of the video here)

I'd like to take a moment to rant about what seems to be "bad" journalism. First, I'd like to pardon Roland Piquepaille, as he represents a fair amount of skepticism in his article. However, the remainder of the blogosphere is taking this "advancement" on dogmatic faith as an absolute truth. Maybe the Israeli team's work is a huge advancement, but maybe it isn't (there just isn't enough data at this point to make a clear distinction). Either way, the blogosphere isn't helping science by disseminating (mis)information. This is just plain wrong, and I hypothesize (along with some colleagues) that this may be true of several other recent "advancements" featured on many blogs.

I make a pledge to represent anything I post as accurately as possible, and to the best of my knowledge (what little I have). Hopefully the other blogs will too.

There is this relatively new class of materials called "electroactive polymers," or EAPs. These devices deform in the presence of an applied electric field, such as in the diagram below.

There are several types of EAPs, such as dielectric and ionic (each with benefits and drawbacks). The important thing to know is that they are well-suited to a variety of applications. They are particularly useful when actuation is required to be fast (compared to shape-memory alloys like Nitinol), low-power, and "natural." This is particularly useful in robotics, where it is hoped that EAPs will form the next artificial muscles. In fact, there is yearly competition sponsored by NASA that aims to have an EAP-powered arm defeat a human at arm-wrestling!

The NASA webpage about EAPs provides tons of useful links and information, including recipes to make your own! Cohen's page also provides some useful insight. (There are also papers about EAP fabrication here and here, though the NASA recipes may be simpler). The easiest solution, however, to just purchase a kit from Environmental Robots, Inc (ERI). The kit shown below can be had for as little as $118.

The field is advancing rapidly, so the online material is probably best. However, if you're interested in a more coherent read, Amazon has several books on the topic, including one by Cohen himself.

The most compelling aspect of EAPs are the potential applications. The applications range from micro-systems, optics, robotics, medical, and even aeronautics. Stay tuned, as I'll be posting write-ups about good number of them!

One of my favorite robots of all time was the Troody robotic dinosaur from MIT.

From the MIT archives page:

Troody, the creation of Peter Dilworth, is a 16 DOF autonomously powered and controlled biped robot built to resemble a Troodon, a small carnivorous dinosaur that lived in the Cretaceous. In this video (below), Troody is shown standing up and walking across a desk (the cables provide power, start/stop control, and safety in case of a fall). Next Troody is shown taking a sharp left turn. Finally, Troody is shown taking a long battery-powered walk from our basement laboratory to visit Cog on the 9th floor (via the elevator). It only fell 4 times along the way.

The frustrating thing is that Peter Dilworth's page on Troody is no longer available (that link to his page returns a 404 error). I find that this happens all too often, and it appears that all the technical specifications of Troody are lost to history (I'll run a publication search later to see if I can find the details there). If anyone knows where all that valuable information can be found, please let me know. I guess this illustrates one of the reasons I started my webpage -- an archive of all the science and technology content that interests me.

Anyway, the archived video is shown below.

Of course, I don't want to lose the video if YouTube ever disappears, so here is a local copy for posterity (it's quite large).

For small robots (in particular), jumping is an efficient means of locomotion. The only energy loss you suffer is from slippage at the jump surface and drag while in flight. This is why so many small animals (such as fleas, grasshoppers, etc) use jumping as their main method of locomotion. Well, consider the image below.

That bug isn't a robot, but it is the inspiration for microrobot vehicles. If you incorporate scavenged energy, electronic brains, micro-scale actuators, and swarm capabilities, you have a very functional system (and possible base platform for large robotic swarms)! Enter Sarah Bergbreiter from UC Berkeley.

For me, mobile autonomous microrobots are defined as millimeter-sized mobile robots with power and control on board. These robots offer numerous advantages due to their size and low power requirements. For example, millimeter-sized microrobots could be used to add mobility to sensors in large-scale sensor networks as the size of those integrated sensors shrink as shown in the Berkeley Smart Dust Project.

At the millimeter size scale, jumping can offer numerous advantages for efficient locomotion, including dealing with obstacles and potentially latching onto larger mobile hosts (larger robots, animals, vehicles, etc).

Sarah and team have been developing a jumping actuator for microrobots. The actuator uses electrostatic "inchworm" motors to add tension to a custom-made silicone (elastomer) micro-rubber band. The rubber band is released, driving a foot/leg which performs the jump. There isn't anything particularly novel about the MEMS techniques, but the use of actuation on a microrobot or sensor platform is a very cool research area (and one that I plan to pursue for my PhD!).

She has two research papers about this device:

• Bergbreiter, S.; Pister, K.S.J. "Design of an Autonomous Jumping Microrobot," accepted to ICRA 2007. (paper pdf)

• Bergbreiter, S.; Pister, K.S.J. “An Elastomer-Based Micromechanical Energy Storage System,” ASME 2006, Chicago, IL, November 5-9, 2006. (paper pdf)

She also has two very cool movies:

Demonstrating the quick release capabilities of the energy storage system. The leg is first held in place by large electrostatic clamps before release and shot an 0402-sized capacitor ~1.5cm along a glass slide.

Inchworm motor pulling an assembled micro rubber band. Watch the parallel flexures on each side to see the 30um of motion. Approximately 5nJ of energy is stored and released.

If you'd like more technical details, I'd check out her papers (above), website, or the MIT Technology Review article on the subject. (I also have local copies of the papers here and here as well as the videos here and here, all for posterity).