Dexter: Dynamically balancing biped
February 28th, 2007 by The Head RotorDexter walks dynamically. Paul Graham explains why that’s more impressive than Asimo. Or you can just watch:
Dexter comes from anybots.com and is our Cool Robot of the Week.
tip o’ the hubcap to Jeremy Zawodny.
February 28th, 2007 at 5:34 pm
Trevor’s robots are very cool!
But actually, a great many robots walk dynamically – including the referenced Asimo. The original (~4 years ago) was choreographed movement, but I saw the latest version at CES in Jan 2007, and they did a demo of it’s dynamic gait – both push back and running/jogging on uneven surfaces (which gets to the point where both feet at some points are off the ground at the same time.)
Jin Sato did the same thing about 2 years ago with off-the-shelf gyros on his 18″ Pirkus (one of which trundles around my office.)
Sony perfected dynamic gaits with the Qrio (nee SDR-4) about 3 years ago, which was really impressive to watch as it went up and down teeter-totters and over pebbles.
Team Osaka takes it further, with 9 DOF sensing (X,Y,Z;R,P,Y;V,S,A) and constant joint positional feedback.
Which isn’t to say what Trevor did isn’t impressive, but there are a great many humanoids with dynamic gait – so the “first” claims are a bit off.
-Mister Robotics, who spends WAY too much time studying gait theory, when he should be working. Wait… that is work. Woo hoo!
March 1st, 2007 at 12:11 am
OK. I stand (cough cough) corrected.
But isn’t there a quantitative difference between Zero Moment Point (Asimo, et al.) and Dexter? When you shove Asimo, does he actually move his feet to compensate, or just kind of push back from a static stance? I get the feeling that the “dynamic” behaviors of Qrio, etc. are kind of just add-ons to the basic ZMP — where you keep the center of gravity above the feet at all times. Or maybe it’s just a matter of how you define “dynamic.”
March 1st, 2007 at 11:39 am
Asimo moves back, so does qrio. And ZMP won’t get you over a teeter-totter when you cross the fulcrum – which is why many humans screw it up.
March 4th, 2007 at 9:52 pm
I’m impressed by the compliance in the joints as well though – they make a good point about the required frame stiffness in the other walkers.
I wonder how the different walkers perform on rougher terrain and with loads?