Slashdot Mirror


Flesh and Machines: How Robots Will Change Us

Peter Wayner writes: "A long time ago, I posed for a portrait at a church fair. The priest wandered by, paused for a second, and then caught up to me later. "Do you like the picture?" he asked. When I said it was fine, he told me, "Oh, I think its terrible. It doesn't look like you at all. But that doesn't matter. The artist is supposed to create a picture of what you think you look like." Read on to see what this has to do with robots as Peter reviews Rod Brook's new book. Flesh and Machines: How Robots Will Change Us author Rod Brooks pages 260 publisher Pantheon Books rating 8 reviewer Peter Wayner ISBN 0375420797 summary A charming look at an unconventional (and powerful) way to think about and design robots.

In a way, robots are portraits of humans. Machines are just machines and assembly lines are just assembly lines. The buckets of bolts don't become robots until they start to take on some of the characteristics and a few of the jobs of humans. A drill for tightening a bolt may replace a biceps, but it's just a motor until it's on the end of a fancy mechanical arm that positions it automatically. Then it's a robot ready for a call from central casting.

Defining just what is and is not a robot is not an easy job for technologists because the replicants and androids are a touchstone and a benchmark for measuring our progress toward the future. It's 2002 and everyone is asking: Where's mad Hal steering a space craft to oblivion? Or more importantly: Why am I still vacuuming the floors and mowing the lawn by myself?

If you are asking these questions, then you might want to read the answers Rod Brooks, the director of MIT's Artificial Intelligence Laboratory, offers in his charming book, Flesh and Machines: How Robots will Change Us. The book is half a thoughtful biography of the various robots created by his graduate students and half a philosophical explanation of what to expect from the gradual emergence of robot butlers.

The biographical part is probably the most enjoyable. He and his students have produced more than a dozen memorable robots who've crawled, rolled and paced their way around MIT. One searched for Coke cans to recycle, one tried to give tours to visitors, and another just tried to hold a conversation. Brooks spends time outlining how and why each machine can into being. The successes and more importantly the failures become the basis for creating a new benchmark for what machines can and can't do.

An ideal version of this book should include a DVD or a video cassette with pictures of the robots in action because the movement is surprisingly lifelike. Brooks is something of a celebrity because a film maker named Errol Morris made a droll, deadpan documentary that cut between four eccentric geniuses talking about their work. One guy sculpted topiary, one tamed lions, one studied naked mole rats, and the fourth was Rod Brooks, the man who made robots. Brooks minted the title for the film, Fast, Cheap and Out of Control, a phrase he uses to describe his philosophy for creating robots. The movie tried to suss out the essence of genius, but it makes a perfect counterpoint for the book by providing some visual evidence of Brooks' success.

One of the stars of the movie was a six-legged robot called Genghis, a collection of high-torque RC airplane servo motors that Brooks feels is the best or most fully-realized embodiment of this fast and cheap approach. The robot marches along with a surprisingly life-like gait chasing after the right kind of radiation to tickle the IR and pyro-electric sensors mounted on whiskers. If you've seen the film, it's hard to forget his gait.

Brooks says that the secret to the success of Genghis is that there is no secret. The book's appendix provides an essential exploration of the design, which is short and very simple. The soul of the machine has 57 neuron-like subroutines, or "augmented finite state machines" in academic speak. For instance, one of the AFSMs responsible for balance constantly checks the force on a motor. If it is less than 7, the AFSM does nothing and if it is greater than 11, the AFSM reduces the force by three. That's doesn't seem like very much intelligence be it artificial or real, but 57 neuron-like subroutines like this are all it takes to create a fairly good imitation of a cockroach.

Brooks calls this a "subsumption architecture" and the book is most successful describing the days that he spent with his graduate students building robots and seeing what the architecture and a handful of AFSMs could do. He half mocks the roboticists who load up their machines with big computers trying to compute complex models of the world and all that is in it. In his eyes, the lumbering old-school machines just move a few inches and then devote a gazillion cycles to creating a detailed, digital description of every plant, brick or wayward child in the field of view. After a few more gazillion cycles, the machine chooses a path and moves a few more inches. Even when they find their way, time passes them by.

There are no complex control mechanisms sucking down cycles on the machines from Brooks' lab, the source of the claim that they're "out of control". It's just AFSMs wired together. One of the robots fakes human interaction by tracking fast motion and flesh colored pixels. Brooks marvels at how a few simple rules can produce a machine that is remarkably life-like. If you're not sure, they have video tapes of lab visitors holding conversations with the machine, who apparently takes part in the conversation with the patient interest of a well-bred host. As if by magic, the AFSMs are creating enough human-like movement and visitor in the tape begins treating the robot like a human!

If you're still not sure, you might buy a "My Real Baby" doll designed by Brooks with the help of the adept mechanical geniuses in Taiwan. The story of taking a highbrow concept from MIT to the local toy store is a great part of the book. The so-called toy is filled with AFSMs that tell it when to gurgle, when to pout, when to sleep, and when to demand sustenance. Alas, the toy makers tell Brooks that the market can't stomach so much innovation. One new thing at a time.

So are these machines truly successful simulacra? Are they infused with enough of the human condition to qualify as the science-fiction-grade robots or are they just cute parlor tricks? Some readers will probably point to the AFSMs and scoff. Seeing the code is like learning the secret to a magic trick.

Brooks, on the other hand, is sure that these machines are on the right track. In a sense, he makes it easier for his robots to catch up with humans by lowering the bar. On the back of the book, Brooks ladles out the schmaltz and proclaims, "We are machines, as are our spouses, our children and our dogs... I believe myself and my children all to be mere machines." That is, we're all just a slightly more involved collection of simple neurons that don't do much more than the balance mechanism of Genghis. You may think that you're deeply in love with the City of Florence, the ideal of democratic discourse, that raven-haired beauty three rows up, puppy dogs, or rainy nights cuddled under warm blankets, but according to the Brooks paradigm, you're just a bunch of AFSMs passing numbers back and forth.

If you think this extreme position means he's a few AFSMs short of a robot professor though, don't worry. Brooks backs away from this characterization when he takes on some of the bigger questions of what it means to be a human and what it means to be a machine. The latter part of the book focuses on what we can and can't do with artificial intelligence. He is very much a realist with the ability to admit what is working and what is failing. His machines definitely capture a spark, he notes, but they also fall short.

He notes with some chagrin that his robot lawnmower leaves behind tufts of uncut grass. Why? It uses a subsumption-like algorithm that doesn't bother creating a model of the yard. The robot just bounces around until the battery runs out. Eventually the laws of random chance mean that every blade should be snipped, but the batteries aren't strong enough to reach that point at infinity. A model might help prevent random lapses, but that still won't solve the problem. Alas, the machines themselves are limited by the lack of precision. One degree of error quickly turns into several feet by the other end of the yard. A robot wouldn't be able to follow a plan, even if it could compute one.

What's missing, Brooks decides, is some secret sauce he calls "the juice". Computation and AFSMs may work with cockroaches, but we need something more to get to the next level. Faster computers can do much more, but eventually we see through the mechanism. Genghis looks cool, but learning about the 57 AFSMs spoils the trick.

The standard criticism of Brooks' machines is that they don't scale. There is no superglue juice that can save a scaffolding built of toothpicks. The AFSM may produce good cockroaches, but that's just the beginning of the game. Humans are more than that. Eventually, the AFSMs become too unwieldy to be a stable programming paradigm. In fact, Brooks sort of agrees with this premise when he suggests that Genghis is his "most satisfying robot." It was also one of the first. The later models with more AFSMs just don't rank.

But humans and other living creatures don't scale either. We may be able to run 20 miles per hour, but only for 100 yards. We may be able to troll for flames on five bulletin boards, but eventually we get our pseudonyms confused. Limits are part of life and we only survive by forgiving them. To some extent, the lifelike qualities of his robots are direct results of the self-imposed limits of the AFSMs.

Your reaction to these machines will largely depend upon how many of the limits you are willing to forgive. Stern taskmasters may never be happy with a so-called robot, but a relaxed fellow traveller may ignore enough of the glitches to interface successfully. Some will see enough of themselves to be happy with the whirring gizmos as a portrait of human and others may never find what they're looking for. That's just the nature of portraits. For me, this book is an excellent portrait of a research program and the collection of questions it tried to answer. You may look in the mirror and want something different, but it's worth taking a look at these machines.

Peter Wayner is the author of two books appearing this spring: the second edition of Disappearing Cryptography , a book about steganography, and Translucent Databases , a book about adding extra security to databases. You can purchase Flesh and Machines from Barnes & Noble. Want to see your own review here? Just read the book review guidelines, then use Slashdot's handy submission form.

5 of 202 comments (clear)

  1. Re:What would Roger Penrose say! by sammy+baby · · Score: 3, Informative

    Old indeed. That's Xeno's Paradox, restated very slightly.

  2. Robots ! by qurob · · Score: 1, Informative


    Robots have taken countless assembly/factory jobs

    Robots are supposed to kill us all anyway

  3. The world is its own best model by Wreck · · Score: 4, Informative
    One of the things I recall about Brooks' work from grad school, was this idea: that the world is its own best model. What that means is, that instead of trying to model the world on a computer then compute what to do based on the model, you should just do stuff and then see how the input from sensors changes. By acting, you interact directly with the "model" -- the world -- and therefore you can cut down on the computation enormously.

    I have the feeling that this notion works well for simple robots, including lower life forms such as insects. Like Genghis, they simple do "simple" stuff based on simple neural computers that hardly warrant the name. But where Brooks' work falls short, as you can see in the review, is where neurons are clumped into serious computers that do model the world. The worst offenders, of course, are humans. The problem is that have no idea how to wire a robot to do that, and a lot of the behaviors we really want from robots rely on it.

    AI still has a long, hard road ahead of it. But we will succeed, eventually, simply by virtue of reverse engineering if nothing else.

  4. Fast, Cheap, and Out of Control by Phrogz · · Score: 3, Informative

    A great movie! I was the web designer who made the official website for the movie (hey, be nice, it was done a LONG time ago) and so got to see the movie before it came out. I watched it 3 times, and made others come watch it. It's so very random and disconnected, and then you start to just see it all coming together.

    Very good movie, and Rodney Brooks is fun to watch. I highly suggest you rent it...just be prepared to be barraged with non-sequitor scene after non-sequitor scene, without a plot but four intermixed lives revealed.

  5. Re:Help me out here. by awaterl · · Score: 3, Informative

    For me, the koan evokes the realization that just as when I close my eyes the room does not become empty, when I randomly wire a neural network it does not become free of preconceptions: it just has random preconceptions.

    That is, it is impossible to free a system of preconceptions. By making parameters random rather than hand-picked, I am simply trading one set of preconceptions for another.

    Of course, if it is a true koan, it will probably evoke as many different thought-paths as it has readers. Hope the above helped, though.