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Animal Robots
hamlet2600 writes "The New York Time is running an article all about how animal like robots [Soul Sucking registration required] are beginning to become more imporant in furthering research. For years reseachers have been trying to make humanoid robots, Honda's ASIMO, MIT's M2 are some notable ones. It seems that more and more researchers are turning to the animal kingdom for "simpler" means of locomotion."
Robotic penguin anyone?
Every neuroscience conference I go to has at least one or two animal like robots.
Would the robot pets 'download' onto your carpet when you aren't home?
I am the lord of the pun. Dance Knave!
Snake robots have been around for some time www.snakerobots.com/main.htm
problem is that they have YET to design a sensor like our inner-ear to detect balance and orientation.
even animals have this "sensor" and the subprocessor systems to not tip over when a leg is lifted before the main processor can detect the change and ask for a balance correction.
too many projects are looking at monolithic processing, which can not handle a complex thing like walking and balance like an organism can.
Think about this, an animal like a dog or housecat is certianly not designed to use stairs, yet they adapt quite easily and quickly to handle them even though they were designed for human motion. A dog's rear leg has extremely limited motion compared to a human leg, yet they adapt to running up a stairwell quite easily, and some dogs can adapt to the point that they can climb a ladder!
MIT had a great program going about 15 years ago about seperating all robotic motion out to seperate processors and allow the main processor to issue interrupts to cause different motion, but I haven't heard from anyone in that program for a really long time. Anyone know if the program is still going?
Do not look at laser with remaining good eye.
Just think, the article's mention of that Disney robot dinosaur:
Bipedal movement is more efficient than quadrapeds. It takes less energy to move the same mass at the same speed using two legs vs four. The problem lies in the inherent instability of bipedal movement. Thankfully, evolution has blessed us with the means to account for this instability. Roboteers don't have the benefit of millions of years and thus an easier solution would be to revert to the less efficient mode of movement involving more than two legs.
B O R I N G
I actually spent this last summer working on M2, so I can tell you a little about how it works. M2 was designed to make use of two nifty ideas, the first being Series-Elastic Actuators (photo)and the other being Virtual Model Control link to pdf journal article).
The series elastic actuators are meant to simulate the interaction of a human muscle-tendon-bone system, and to allow for the design of a low-impedance system. M2 is designed to actually mimic the inherent low-impedence (low-stiffness) mechanical system that people represent. People are really awful at position based/high-impedance control, which is what most traditional robots use. This is useful for manufacturing, when you want the robot arm to always put the bolts in the same place, but leads to stereotypical "robot" movement (like the guy spastically jerking around on the dance floor). People are pretty good at force control though (there are all sorts of biological reasons for this). So M2 was built to be low-impedance like a person by using these S-A Actuators.
Virtual Model Control is supposed to allow more a more intuitive control of a robot by simulating it as a mechanical system. VMC lets you basically define springs and dampers at different points which are then simulated by the actuators. So to keep M2 standing, you might make a granny-walker out of springs, and to make it walk you could "attach" a spring to its chest pulling it forward. VMC has been implemented in simulation (where it works great), but it's not quite ready in real life.
The really cool thing about M2 is its potential. It already moves much more fluidly and naturally than any other robot out there, and its not nearly done yet. Once its working properly, it'll be able to walk essentially blindly (becuase its low impedance) like a person, rather than needing to know exactly where to place each foot (*cough*ASIMO*cough*) to keep from shattering itself.
If anyone has any other questions about how M2 actually works, I'd be happy to answer them.
-Zach
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