Servo - April 2009

maybe the Georgia Tech guys don’t get out much. In any event, according to Daniel Goldman, assistant professor in the School of Physics ( www.physics.gatech.edu), “Sand is a uniquely challenging terrain because it can shift quite easily from solid to fluid to solid and requires different locomotion strategies.”

Experiments were conducted by placing a device with six C-shaped legs on an eight-foot trackway filled with poppy seeds, which simulates conditions that might be found in deserts, extraterrestrial surfaces, and a number of agricultural operations in Afghanistan.

The result? “We have discovered that when a robot rotates its legs too fast or the sand is packed loosely enough, the robot transitions from a rapid walking motion to a much slower swimming motion.”

The researchers discovered that the bot can easily traverse the grit if it maintains a constant rpm and some parameters are properly adjusted: the durations of the slow and fast phases and the angle at which each limb changes from slow to fast. But in a pinch, you can just pour some water on the sand.

Robot Darwinism?

In a curiously abstruse press release, researchers at Aberdeen, Scotland’s Robert Gordon University ( www.rgu.ac.uk) claim to have “caused a stir in the world of engineering by taking the first steps in developing a robot that has the ability to evolve in the same way as animals.” They say that the technique “offers the potential to make machines which can interact with their environment and perform useful tasks in difficult or dangerous circumstances — or even around the home.

It does this by gradually

Skippy the mudskipper. Courtesy of the Aquarium of the Pacific; photo by Hugh Ryono.

developing the robot’s body and environment from simple to complex, while at the same time growing its brain (a special control circuit called an `artificial neural network’) by adding new parts — one on top of the other — to end up with a structure rather like the layers of an onion.

Using this system researchers have produced a complex robot. The robot started off pulling itself along in a primitive way — rather like a `robotic mudskipper’ — and then went through a series of developing body plans, actuators, sensors, and environments until it had evolved into a walking quadruped, able to react to visual stimuli, avoid obstacles, and react to predefined objects as `predators’ or `prey.’

Unfortunately, no details were offered as to how it accomplishes such evolutionary upgrades, and there were no accompanying photos that might give us a clue. But the announcement inadvertently posed a much more interesting question: “What the heck is a mudskipper?” For a fascinating answer, visit www. aquariumofpacific.org/online learningcenter/species/mudskip per. This is evolution at its best.

Morose, Rejected Fauxbots

The way the yarn goes, 100

Robytes

The Mellowtron stuffed robot in need of Prozac®. Photo by Bill Brown.

Mellowtron robots (not to be confused with the Mellotron tape-loop keyboards employed by the Moody Blues et al. back in the good ol’ days) were created and sold as service robots. But the only service they were designed to perform was to dream all day.

When their owners discovered that the Mellowtrons could not cook, clean out the cat box, or otherwise assist around the house, they were all fired, sent back to the factory, and dumped in a warehouse where they are now idle, sad, and confused.

If this somehow brings a tear to your eye, be advised that you can adopt one of the little slackers by logging onto www.stuffedrobot. com and shelling out $70 (plus S&H). Although they all look exactly the same, each one professes to have its own story and personality. No. 32, for example, has trouble distinguishing between reality and his dreams. No. 47 gets his feelings hurt if everyone doesn’t say “hi” to him. And so on.