[Paleopsych] NS: Organised chaos gets robots going

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Organised chaos gets robots going
http://www.newscientist.com/article.ns?id=dn6582&print=true
      * 09:45 01 November 2004
      * Will Knight

    A control system based on chaos has made a simulated, multi-legged
    robot walk successfully. The researchers behind the feat say it may
    have brought us closer to understanding how people and animals learn
    to move.

    Standard robots control their leg motion either through complex
    computer programs or by using so-called genetic algorithms to evolve a
    successful walking strategy. Both these options are time-consuming and
    require a lot of computer power.

    Roboticists Yasuo Kuniyoshi and Shinsuke Suzuki wondered whether
    chaotic systems might also generate efficient walking behaviour.
    Chaotic systems behave in a way that means that small effects are
    amplified so rapidly that the systems behaviour becomes impossible to
    predict more than a short time ahead. Such chaotic systems are behind
    a number of phenomena, including the weather and the performance of
    financial markets.

    The Tokyo University pair reasoned that just as the chaotic maths that
    determines the weather can produce clear patterns such as hurricanes
    and weather fronts, similar systems might underlie the movement
    patterns involved in locomotion. We, and animals, seem to be able to
    work out how to move in different situations without going through
    thousands of trial-and-error situations like todays robot-control
    software does, says Kuniyoshi.

    To test their idea, Kuniyoshi and Suzuki devised a computer simulation
    of a 12-legged machine in which each leg was controlled by a chaotic
    mathematical function. The functions were initially fed 12 parameters
    chosen at random. From then on, sensory information from each limb was
    fed back into the chaotic function that controlled it.

Going nowhere

    The team found that certain combinations of starting parameters made
    the robots limbs rapidly adopt walking-on-the-spot behaviour, but the
    machine did not get anywhere. However, when they placed a weight at
    one end of the simulated robot (see graphic) they found that four of
    the legs seized up, allowing the front and back legs to dominate
    movement and let the robot scamper along.

    The robot could also negotiate obstacles in its path. After scuttling
    about for a few seconds, its mode of locomotion would change to allow
    it to scramble over whatever was in the way. Although it was just a
    simulation, the software mimicked the robots performance in fine
    detail. Kuniyoshi is confident that the trick will work in a real
    robot.

    Remarkably, the robot performed these tricks without any conventional
    programming. And its behaviour emerged far more quickly than it would
    if it had used genetic algorithms. Kuniyoshi suggests that his chaotic
    approach may have similarities to the way that biological systems
    learn to move.

    Many findings point to the presence of chaotic patterns in general in
    the human brain, says Max Lungarella, who researches artificial
    intelligence at the University of Tokyo. But Kuniyoshi and Suzukis
    approach is still unconventional, he says. It diverges radically from
    the traditional way of thinking about intelligence.

    Roberto Fernández Galán, a biophysicist at Carnegie Mellon University
    in Pittsburgh, Pennsylvania, also finds the approach intriguing, but
    he is sceptical about the Japanese teams idea that chaos plays a role
    in animal locomotion. It is surprising to achieve what they call
    goal-directedness with a chaotic robot, he says.

Related Articles

      * [14]Walking robot carries a person
      * [15]http://www.newscientist.com/article.ns?id=dn4409
      * 21 November 2003
      * [16]Nine eyes help robots to navigate
      * [17]http://www.newscientist.com/article.ns?id=dn4322
      * 30 October 2003
      * [18]Robot spy can survive battlefield damage
      * [19]http://www.newscientist.com/article.ns?id=dn4075
      * 20 August 2003

Weblinks

      * [20]University of Tokyo
      * [21]http://www.u-tokyo.ac.jp/index_e.html
      * [22]Max Lungarella, University of Tokyo
      * [23]http://www.isi.imi.i.u-tokyo.ac.jp/~maxl/
      * [24]Roberto Fernández Galán, Carnegie Mellon University
      * [25]http://www.andrew.cmu.edu/user/rfgalan/home.htm

References

   14. http://www.newscientist.com/article.ns?id=dn4409
   15. http://www.newscientist.com/article.ns?id=dn4409
   16. http://www.newscientist.com/article.ns?id=dn4322
   17. http://www.newscientist.com/article.ns?id=dn4322
   18. http://www.newscientist.com/article.ns?id=dn4075
   19. http://www.newscientist.com/article.ns?id=dn4075
   20. http://www.u-tokyo.ac.jp/index_e.html
   21. http://www.u-tokyo.ac.jp/index_e.html
   22. http://www.isi.imi.i.u-tokyo.ac.jp/~maxl/
   23. http://www.isi.imi.i.u-tokyo.ac.jp/~maxl/
   24. http://www.andrew.cmu.edu/user/rfgalan/home.htm
   25. http://www.andrew.cmu.edu/user/rfgalan/home.htm

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