Researchers at the NanoRobotics Laboratory of the École Polytechnique de Montréal, in Canada, are putting swarms of bacteria to work, using them to perform micro-manipulations and even propel microrobots.
Led by Professor Sylvain Martel, the researchers want to use flagellated bacteria to carry drugs into tumors, act as sensing agents for detecting pathogens, and operate micro-factories that could perform pharmacological and genetic tests.
They also want to use the bacteria as micro-workers for building things. Things like a tiny step pyramid.
The video below shows some 5,000 bacteria moving like a swarm of little fish, working together to transport tiny epoxy bricks and assemble a pyramidal structure -- all in 15 minutes.
The video was presented at the IEEE International Conference on Intelligent Robots and Systems last year, along with a wonderfully titled paper, "A Robotic Micro-Assembly Process Inspired By the Construction of the Ancient Pyramids and Relying on Several Thousands of Flagellated Bacteria Acting as Workers."
The bacteria, of a type known as magnetotactic, contain structures called magnetosomes, which function as a compass. In the presence of a magnetic field, the magnetosomes induce a torque on the bacteria, making them swim according to the direction of the field. Place a magnetic field pointing right and the bacteria will move right. Switch the field to point left and the bacteria will follow suit.
Each bacterium has flagella capable of generating about 4 piconewtons. It's a very small amount of thrust force, but put thousands of bacteria to work together and they can move mountains. Well, micro mountains.
Several research groups are trying to develop MEMS devices that emulate the propulsion mechanisms of bacteria. Martel asks, Why mimic the bacteria when you can use the little things themselves?
Martel and his colleagues developed an electronic microcircuit that contains both the bacteria and an array of conductors that produce magnetic fields. By carefully controlling which conductors are active, the microcircuit can make the bacteria move in specific directions. A computer and an optical microscope provide a feedback loop, tracking the motion of the bacteria and adjusting the conductors to achieve the desired behavior.
In addition to pyramid building, Martel's bacteria has done some other neattricks, such as traveling through the bloodstreams of rats, steered by an MRI system, a la "Fantastic Voyage."
One of their current projects is developing an autonomous bacterial microrobot. They plan to use standard CMOS processes to create a chip containing both electronics and bacteria. The bacteria would reside in micro-reservoirs designed to generate thrust. For control, small conductors inside each reservoir would produce magnetic fields.
Several of these microrobots could then be used to perform tasks collectively, perhaps one day swimming inside our bodies, delivering drugs, detecting disease, and fixing an organ here, a blood vessel there. Who knew bacteria could be good robots?
UPDATE:If you're wondering which ancient pyramid inspired the researchers -- and is shown in the video on the left bottom corner -- it's the Djoser step pyramid, in Egypt, which the researcher note was "an important, initial milestone in the history of man-made structures."
Kevin Kelly from Wired recently interviewed Jamie Hyneman and Adam Savage from Mythbusters for the Commonwealth Club of California. As part of the interview, Adam and Jamie were asked (somewhat jokingly) whether they’re afraid that machines will take over in the future, particularly with regards to the present development of armed robots.
Now, if you’ve been reading this blog for a while, you’re probably aware that this is one of my favorite subjects to harp on, and as much as I respectadmireworship ::cough:: like-in-a-strictly-professional-manner Adam Savage, I won’t let you down.
So, is it a bad idea to give a machine a gun? Of course it is. It’s a terrible idea. But guns were a terrible idea to begin with (from a lofty ethical viewpoint, anyway). The terrible part about guns is that guns can kill people, and not giving guns to robots isn’t going to change that. Really, the question should be, is giving guns to machines a better or worse idea than not giving guns to machines? This where I think armed robots have a use.
I guess fundamentally, the part that I don’t understand is where Adam says that he knows how machines work and he wouldn’t trust a machine with a gun. I wonder, though, if we have a better idea of how most machines work than how some humans work… Like, it’s a fundamental right for humans to have guns, and there are plenty of humans out there who are far less predictable or reliable than a robot. It’s certainly true that robots are more prone to things like mechanical failures, but we already entrust our lives to robots on a daily basis (often without realizing it). Giving a robot a gun is just an especially obvious way of making it dangerous.
I hate to keep coming back to this analogy, but it’s like driving a modern car: between things like anti-lock brakes and cruise control and (now) parking and lane assist features, your car (if you have a fancy one) has the ability to control your brakes, your accelerator, and your steering. If you have power windows and door locks, it has control over those things, too. It’s only designed to be autonomous in very specific situations, but what we’re talking about here is mechanical (or software) failure. And generally, that just doesn’t happen, because cars have been designed and tested with safety and reliability in mind. I don’t see why it couldn’t be any different with armed semi-autonomous (or even autonomous) robots.
Whether or not it’s ethical to arm robots is (I’d like to think) a separate issue. The short answer? No, it’s not. As has been pointed out, arming a robot makes it easier to resort to violence since the consequences are much less severe. Some people might even argue that that reason alone should keep robots out of combat, but I doubt that those people are going into combat themselves. My guess (and this is really just a guess since I’m in no way qualified to make any other sort of comment) is that if some kind of armed conflict is inevitable and there is substantial risk of injury or death, most people who’d be directly involved in that conflict would rather send a robot in their place if possible. And, that’s really what it’s all about: robots doing the dangerous things so that humans don’t have to.
I remember when, a decade ago, Kevin Warwick, a professor at the University of Reading, in the U.K., implanted a radio chip in his own arm. The feat caused quite a stir. The implant allowed him to operate doors, lights, and computers without touching anything. On a second version of the project he could even control an electric wheelchair and produce artificial sensations in his brain using the implanted chip. Warwick had become, in his own words, a cyborg.
The idea of a cyborg -- a human-machine hybrid -- is common in science fiction and although the term dates back to the 1960s it still generates a lot of curiosity. I often hear people asking, When will we become cyborgs? When will humans and machines merge? Although some researchers might have specific time frames in mind, I think a better answer is: It's already happening.
When we look back at the history of technology, we tend to see distinct periods -- before the PC and after the PC, before the Internet and after the Internet, and so forth -- but in reality most technological advances unfold slowly and gradually. That's particularly true with the technologies that are allowing us to modify and enhance our bodies.
Radio chips like Warwick's are just one of the technologies people have had implanted in their bodies. As Rodney Brooks wrote in a recent IEEE Spectrum article:
Our merger with machines is already happening. We replace hips and other parts of our bodies with titanium and steel parts. More than 50 000 people have tiny computers surgically implanted in their heads with direct neural connections to their cochleas to enable them to hear. In the testing stage, there are retina microchips to restore vision and motor implants to give quadriplegics the ability to control computers with thought. Robotic prosthetic legs, arms, and hands are becoming more sophisticated. I don't think I'll live long enough to get a wireless Internet brain implant, but my kids or their kids might.
And then there are other things still further out, such as drugs and genetic and neural therapies to enhance our senses and strength. While we become more robotic, our robots will become more biological, with parts made of artificial and yet organic materials. In the future, we might share some parts with our robots.
Watch the video above to see Amanda Kitts, who lost left arm in a car accident, demonstrating advanced hand control of the DEKA arm in a study at at the Neural Engineering Center for Artificial Limbs, part of the Rehabilitation Institute of Chicago. Amazing!
Or consider the case of Dawn O'Leary, a woman from Maryland who had both arms amputated after an accident. She was fitted with a prosthetic hand by Touch Bionics called i-Limb. The device uses sensors on her skin to pick up nerve signals and operate the bionic digits, enabling her to carry out complex tasks such as grasping the handle of a cup. From a report in the local newspaper:
Holding something is what O’Leary was excited to try. She said she was able to hold a mug and pick up a tissue. She said she wants to learn how to use the computer and holding a rod and reel.
One thing she really wants to do is hold a crayon.
"I want to be able to color with my grandkids," she said.
(Watch a video of O'Leary trying the device here.)
These are just two examples of how technologies are evolving in our path to cyborg life. Along the way, we'll have to address many safety, privacy, and most important, ethical issues. Nevertheless the advantages of becoming bionic people are too enticing. I can imagine a time when we'll all become part of an ubiquitous flesh-and-silicon world where our bodies and devices are constantly communicating. Or as Warwick put it:
Will we evolve into a new cyborg community? I believe humans will become cyborgs and no longer be stand-alone entities. What we think is possible will change in response to what kinds of abilities the implants afford us. Looking at the world and understanding it in many dimensions, not just three, will put a completely different context on how we -- whatever "we" are -- think.
A rookie, all-girl team ran their robot to victory in a ball-kicking tournament held last weekend at Manhattan’s Javits Center. The team, from the Mary Louis Academy (TMLA), a Catholic, all-girls high school in Queens, will go on to Atlanta’s Georgia Dome next month to compete with hundreds of other robotics victors for the grand championship. The annual cycle of tournaments is sponsored by FIRST (For Inspiration and Recognition of Science and Technology), a nonprofit established by inventor Dean Kamen in 1989.
The game’s like soccer, but played by boxy robots on wheels (see video above). The field sports two raised bumps, dividing it into three sections, in order to challenge kids’ design minds. Robots can either slide under open spaces between the bumps or crawl over the bumps, aiming to roll or kick balls into goals on the ends of the field.
Two alliances of three teams each compete in each round, meaning there are always six robots on the field at any one time. Each round lasts 2 minutes and 15 seconds, with the robots running purely autonomously, according to pre-programmed code, for the first 15 seconds. Sixty-four teams competed in the NYC regional games last weekend.
The TMLA team formed this year at the instigation of Kathy Rutherford, a 1979 TMLA graduate who has judged FIRST competitions for the past six years and is an electrical and biomedical engineer and a senior IEEE member. To get her alma mater more involved in engineering, she introduced the school’s principal and math department chair to the competition last year, and now she’s seeing the fruits of her (and the girls’) labor.
“It’s better than my 30-year reunion,” Rutherford says, watching the girls scurry around their robot, tightening bolts and attaching zip ties to loose wires. “It’s really about how you inspire the next generation, and here they are!”
In January, when this year’s game challenge was announced and kits containing critical parts were handed out to eager teams around the world, TMLA science teacher and FIRST team mentor Vinod Lala told Spectrum that the girls were mainly interested in getting their feet wet, learning about the competition, and just building something in their first year. They didn’t even have a catchy name for their robot, calling it simply “TMLA.” But they went much farther than they’d planned.
When they heard their team number called during the playoffs “draft” last Sunday, Lala says, some of the girls had to look down at their T-shirts to make sure they’d heard right. “We had to pick our jaws up off the floor,” he says. Team captain Vanessa Ronan was surprised, but ran to the field to accept the invitation to join the top-ranked alliance.
Angela Guiliani, another TMLA team member, agrees that her team wasn’t expecting to make it to qualifying rounds. “It’s not that we weren’t doing well,” she says, “but we hadn’t even gotten our [ball] kicker working yet.”
That turned out not to matter, because the alliance wanted them for a different purpose: defense. “Our robot was moving really well,” Guiliani says, even if it didn’t kick, and she thinks that’s why they were picked; the robot could deftly protect its partners and stop the opposition from scoring goals.
Together with their partners from Wissahickon High School, in Pennsylvania (Miss Daisy), and New York’s Stuyvesant High School (Stuypulse), TMLA advanced through two quarterfinal rounds and into semifinals. Their alliance’s strategy was working perfectly.
Then, after an aggressive shove from another robot, a wheel and chain flew off TMLA’s robot, putting it out of commission. Rather than waiting while they replaced it, holding up the game, the alliance chose a replacement team—incidentally the only other all-girls team participating in the regional competition, the Iron Maidens of the Bronx High School of Science.
But the deal was that if the alliance won, then all four teams, including TMLA, would be qualified for the championship games in Atlanta.
The battle was fierce. With the Iron Maidens playing defense, blocking goals their opponents tried to score, the alliance advanced to finals. They won their first round, bolstered by the Stuyvesant robot’s ability to hook onto the railings in the center of the field and hoist itself off the ground—an action earning them extra points.
A tense second round left the group with more points than the opposition, but due to penalties they lost the match. They pulled their robots off the field, made final adjustments, and set up for round three, the final countdown.
They won handily. The bleachers erupted with cheering from the fans. Kids screamed and jumped up and down and hugged and high-fived. The captain of Stuyvesant’s team pulled out his phone and started texting madly.
Now the winning teams are headed to the championships, and with them go the rookies—no longer quite so rookie—of TMLA. Only about 16 percent of rookie teams advance to the championship each year, according to FIRST spokespeople.
“It’s a bit of a Cinderella story,” says TMLA’s principal, Sister Kathleen McKinney. “We went into this as kind of an unknown… There aren’t that many all-girls teams, and not that many Catholic schools" involved in the program, she says. Their team didn’t have any sponsors, receiving funding instead from a group of generous alums. The fact that they get to advance their first time in the game, McKinney says, is “really exciting.”
The girls are wearing their team shirts at school and getting congratulated in the halls. Lala’s classes even applaud when he walks into the room.
It’s not all wine and roses, of course. Lala is exhausted, and says he was looking forward to a break. But he’s very proud of the team, and ready to dedicate another month to the project. “I’ve sacrificed four or five months—what’s one more?” he says. He’s already fielding questions from girls who want to join the team next year.
Greg Ronan, the team’s parent mentor and a fiber optics engineer, says that FIRST is great for the girls because it gives them exposure to things they don’t normally get to do—like machining robot parts.
The other good thing, he adds, is that some kids may already like this kind of tinkering, but FIRST helps them discover that they’re not alone. “It’s important to know others are interested in the same things,” Ronan says.
As for whether they will actually get to go to the championships in Atlanta, having now qualified, McKinney is emphatic: they’re going, whatever it takes. “If it was our basketball team, or our speech team, and they qualified, we’d send them,” she says. “This is just as important.”
That’s music to the ears, and the reason FIRST exists: to make sure people realize that science and engineering really are as important as other sports.
Photo: TMLA, Wissahickon HS, and Stuyvesant HS students planning their alliance strategy.
Early this year I asked you to tell us about your human-robot interactions. Now that I've collected a raft of very interesting stories about people interacting with robots in the workplace and public spaces, I can share some of my findings (which I will discuss in more detail at next quarter's IEEE Robotics & Automation Magazine).
So one of the things I discovered is that we may be learning to predict how people will interact with robots: Who will treat a robot as a social being and who will treat it like a box of electronics. The answer may be as simple as whether or not the person greets the robot.
I find this particularly intriguing because when I was a pre-schooler, my mother used to scold me regularly for refusing to say "hello" to people. For some reason, I couldn't understand the social purpose of a greeting.
"But it doesn't mean anything," I would complain. The explanation that I should do it because everyone else did just didn't hold water in my four-year-old mind.
So why do we greet each other? Well, maybe way back, greetings were a means for assessing friend vs. foe. In civilized society, though, they're used more as a recognition of each other's existence, and co-consciousness, a concept rigorously defined by Philippe Rochat in his recent book "Others in Mind - Social Origins of Self-Consciousness." There, Rochat, a professor of psychology at Emory University, in Atlanta, describes the tension between people's first-person views of themselves and third-person views. Of course, third-person views are really inferred from other people's perceived reactions to you. Until we network wetware, we can only guess at how each other actually experience us.
So saying "hello" is a basic communication to validate another's existence, to "co-construct" consciousness that we both exist, or as Rochat puts it, "We think, therefore, I am."
The interplay between people and our creations in the workplace is different than that with purely social robots or with purely industrial robots. I hope you enjoy delving into "When People Meet Robots in the Workplace," to appear in the next issue of Robotics & Automation.
Jeanne Dietsch is co-founder and CEO of MobileRobots, based in Amherst, N.H.
Scanning a book manually, page by page, is a slow, mind-numbing task. Google has had some ideas on how to speed up the process, but apparently these methods are still limited by how fast humanhands can manipulate a book's pages before an image-capturing system.
Google, meet Masatoshi Ishikawa, a professor at the University of Tokyo. Ishikawa is well known in robotics circles for his Matrix bullet time-style amazingdemos -- like a robo-hand that can catch objects in midair with superhuman speed. How he does it? He built a "Super Vision Chip" (that's what he calls it) that can "see" events too fast for the eye.
Ishikawa and his colleagues are already working on several applications -- including a microscope that can track individual bacteria and a video game motion-capture system for gesture playing. Late last year when I visited the lab, they showed me their latest creation: a superfast book scanner.
The system, developed by lab members Takashi Nakashima and Yoshihiro Watanabe, lets you scan a book by rapidly flipping its pages in front of a high-speed camera. They call this method book flipping scanning. They told me they can digitize a 200-page book in one minute, and hope to make that even faster.
The camera operates at 500 frames per second, with a resolution of 1280 by 1024 pixels. For each frame, the system alternates between two capture modes. First it shines regular light on the page and captures text and images. Then a laser device projects lines on the page and the camera captures that as well.
The scanned pages are curved and distorted, but the researchers found a way to fix that. The laser pattern allows the system to obtain a page's three-dimensional deformation using active stereo methods. So they wrote software that builds a 3D model of the page and reconstructs it into a regular, flat shape.
The system is currently a prototype that occupies an entire lab bench. But in the future, they hope to simplify and miniaturize it for integration into portable devices like a smartphone. So one day you might be able to flip the pages of a book in front of your iPhone and get a digitized version in seconds.
True, it might not be a perfect, high-resolution copy of the book. The scanning process might skip pages and, well, your fingers might appear in the images. And that's not to mention all the copyright questions.
In fact, Watanabe told me he was particularly interested in scanning manga comics. Imagine, he said, if all of Japan's vast manga archives, at libraries, homes, and elsewhere, could be rapidly scanned and shared among manga fans around the world. That'd be nice. Alas, when he contacted one publisher, they didn't like his idea and forbade him from using their books for testing the scanning device. Watanabe currently uses a mock book he made himself.
At this weekend’s FIRST robotics NYC regional competition, FIRST founder Dean Kamen could be spotted signing autographs—often on T-shirts and hats—for eager high schoolers, or chatting with kids and fellow FIRST officials. It was refreshing to see them go ga-ga over a “rock star” inventor instead of a Hollywood celebrity (no offense to celebrities, of course).
During a few moments when he wasn’t working the crowd, Kamen took time to tell me what goes into planning each year’s robotics challenge, and to explain what he likes best about FIRST.
The robotics competition presents high school teams with a new challenge each year—this year’s task was to roll or kick soccer-like balls into goals while navigating obstacles on a playing field a little smaller than a basketball court. Kamen says his game design team changes the challenge every year because they don’t want returning teams to have a huge advantage over rookies, or to get bored and not come back each year.
They also want to focus on teaching kids how to solve new, complex problems, where in most other sports, Kamen says, “you’re learning how to optimize something that people have been doing for a long time.
“We try to emulate other sports, with the passion and the excitement and the instant gratification and the winners and the trophies...In many was we think it’s better than the academic or corporate model,” Kamen says. But in some cases, the sports model doesn’t apply.
Take NASCAR. “The cars are all identical, other than the logo from the advertising,” Kamen says, because the vehicle has been optimized. It has to be really low and really fast, for example. “But engineering innovation is [about] the discontinuity: a whole new approach, a whole new problem, a whole new solution,” Kamen says.
“We don’t want FIRST to become an optimization exercise,” he says. Instead, he wants the wow factor, for kids to open the box of parts each year and say wow, what is this stuff?!
This year’s game, for which young robot builders had to take into account several different features—the shape of raised bumps in the field, the size of the balls, and the height of bumper-like ramps on the goals that robots would have to roll up, rather than kicking straight and level—made the game “substantially more difficult” than the game designers expected, Kamen says.
But the kids “rise to the occasion,” he adds, and “they’re getting better and better by the day.”
True that. While Friday’s practice rounds often ended with no points scored, the final rounds on Sunday boasted several scores of seven or eight points, and almost never sported 0. Watching teams go from opening rounds to final rounds in each of the regional competitions, Kamen says, “you feel like you just watched kids go from T-ball to the World Series before your very eyes.”
One challenge with getting spectators excited about the game has been its complicated scoring system. In the past, Kamen says, “it was very hard to figure out who was winning until the game was over.”
This year the design team focused on making it easy for the audience to understand, complete with a real-time scoring system, with points and penalties listed immediately after each round. As an audience member, I thought it certainly made the game fun to watch, and it kept the kids’ energy high.
Kamen is proud that FIRST fosters kids who are “intensely competitive and simultaneously gracious.” The proof was evident: despite team spirit that brought out painted faces, capes, caps, and even a marching band, the teams still remembered that they were working together. In one instance in the “pit”—a huge, bustling area where teams and their robots and tools occupy tradeshow-like nooks—an announcer broadcasted that one team needed black electrical tape. Sure enough, a few seconds later, someone from another team zipped over with a roll of it.
Another broadcast was on behalf of a team looking for a fuse, which was shortly provided. So while the teams compete for top honors, they also learn fundamental cooperation skills. Can you imagine a football team offering a spare helmet to the opposition?
FIRST awards exist for this kind of behavior, namely the coveted Chairman’s Award, given for the team that best represents the goals of FIRST: respect, professionalism, and honoring science and technology. Other awards recognize top mentors, gracious professionals, innovators, and team spirit.
This year, Kamen introduced a new award: the Dean’s List (chuckles all around). This will go to student leaders who foster awareness of FIRST and its mission of spreading enthusiasm for science and technology to their communities. The award is also meant to inspire kids to continue as leaders of the FIRST alumni community (of which I am a proud member).
What Kamen is most proud of, however, isn’t the engineering, or the game. “In six weeks, you can’t expect kids to fundamentally grasp all of the sophisticated disciplines of engineering,” he explains. “The robot is just a vehicle, no pun intended. What they’re really building are serious relationships between kids and adults. Kids are building confidence, respect for each other, their teams.”
What’s more, he adds: “Every kid on every one of our teams can turn pro. You can’t say that about football or basketball.”
French service robotics company Robosoft has introduced a robot called Kompaï designed to assist elderly and disabled people and others who need special care. The mobile robot talks, understands speech, and can navigate autonomously. It reminds people of meetings, keeps track of shopping lists, plays music, and works as a videoconference system for users to talk with their doctors, for example.
The video below is pretty awesome. It shows a senior at Broca Hospital, in Paris, interacting with the robot after receiving only a few minutes of training. The man asks the robot about the time, date, and whether he has any appointments that day; Kompaï gives answers in a computerized voice.
"Robot?" the man says. "What can I do for you?" Kompaï responds. The man asks what is on the shopping list. "Fourteen apple, four cheese, and 18 tomato," the bot responds. The man says, "Add five eggs to the shopping list." Done.
The video also demonstrates how the man uses the robot when he doesn't feel well. "Robot, I'm not fine," the man says. "Where does it hurt?" Kompaï replies. The robot goes on to ask a series of questions and then tells the man that it sent that information to his doctor by email.
My favorite part is toward the end, when the man gives the robot the following command:
"Robot," he says, "leave me alone."
"OK. I stop talking. Call me when you like," Kompaï responds and promptly leaves the room.
This is how Robosoft describes Kompaï:
It is a mobile and communicative product. Somewhat like a dog, it has its "basket," which is the recharging dock that it heads back to when its batteries are low. Equipped with speech, it is able to understand simple orders and give a certain level of response. It knows its position within the house, how to get from one point to another on demand or on its own initiative, and it remains permanently connected to the internet and all its associated services.
Its primary means of communication with people is speech, with an additional touch screen that features simple icons. Future generations of Kompaï will be equipped with visual abilities, and also the possibility to understand and express emotions. And later, the addition of arms will allow it to handle objects, leading to meal preparation and tidying; more practical functions, yet still fundamental in everyday life.
The first generation of the robot, to be officially introduced next week at the Intercompany Long Term Care Insurance Conference in New Orleans, is an R&D platform, "intended for developers who would like to implement their own robotics applications for assistance," Vincent Dupourqué, CEO of Robosoft, said in a statement.
In a recent video, Willow Garage researcher Eitan Marder-Eppstein describes the open-source navigation stack they've released as version 1.0. The code, available at http://ros.org/wiki/navigation, was designed to be flexible and cross-platform, he says, and could be used in anything from a small iRobot Create-based bot to a large multi-sensor robot like Willow's own PR2 (which Spectrum has covered in detail here and here).
The stack lets users configure different sensors, change the footprint of the robot, integrate SLAM systems, and use a 2D or 3D view of the world. Says Marder-Eppstein:
"In particular the three-dimensional view of the world enables the robot to avoid obstacles like tables, chairs, and people's feet."
And a guy trying to hit it with a two-by-four.
"This is a significant improvement over navigation stacks that view the world as purely planar," he says.
I like Willow because their work is practical and promising. And because they have a sense of humor. They really put their bodies on the line.
Kojiro is an advanced musculoskeletal humanoid robot under development at the University of Tokyo's JSK Robotics Laboratory. Kojiro's creators designed its body to mimic the way our skeleton, muscles, and tendons work to generate motion. The goal is to build robots that are light and agile, capable of moving around and interacting with the physical world in the same way our flesh bodies do.
I met Kojiro during a visit to the JSK lab late last year. Masayuki Inaba, a professor at Tokyo University, and Yuto Nakanishi, a researcher and one of Kojiro's main developers, showed me their latest trick: using a PS2 controller to make Kojiro move. In particular, they wanted to demo the robot's spine motion.
Other research groups are also exploring the idea of anthropomimetic humanoids. But I don't think many of them have a flexible spine, which is one of Kojiro's main innovations. Like the human spine, Kojiro’s can bend in different directions to let the robot arch and twist its torso. It can't quite dance the Macarena yet, but it shows some promising hip moves.
Nakanishi explained to me that most humanoid robots have articulated limbs and torsos powered by DC motors at the joints. Although these robots have a good range of motion, they're typically hard and heavy, making collisions with humans and objects a big problem.
Kojiro does use DC motors, but the motors pull cables attached to specific locations on the body, simulating how our muscles and tendons contract and relax. These tendon-muscle structures -- Kojiro has about 100 of them -- work together to give the robot some 60 degrees of freedom, or much more than could be achieved with motorized rotary joints.
And instead of big, bulky DC motors, Kojiro uses lightweight, high-performance ones. Its brushless motors are quite small (16 millimeters [0.6 inches] in diameter and 66.4 mm [2.5 inches] in length) but can deliver a substantial 40 watts of output power.
Each motor unit has a rotary encoder, tension sensor, and current and temperature sensing circuit. A driver circuit board automatically adjusts the current fed to the motors based on temperature measurements. The results are transmitted to a computer and displayed on a control screen developed by Takanishi.
To make the robot safer, the researchers built its body using mostly light and flexible materials. To keep track of its posture and limb positions, they embedded joint angle sensors on spherical joints and six-axis force sensors on the ankles. For balance, the robot uses three gyros and a three-axis accelerometer on its head.
The main drawback of using a musculoskeletal system is that controlling the robot's body is difficult. This kind of system has lots of nonlinearities and is hard to model precisely. To develop control algorithms for Kojiro, the JSK team is using an iterative learning process. They first attempt small moves and little by little tweak the control parameters until the robot can handle more complex movements.
Eventually they hope to integrate control for the head, spine, arms, and legs. Then Kojiro might do the Macarena.