Walker robot progress

Posted on 2009-07-15 by M. Eric Carr

Well, it moves. The gait algorithm is still handcoded instead of evolved (I’m working on finding a physics sim I can use for that), and is less than efficient — but at least it’s going in the right direction. The plan is for it to eventually be a hexapod — maybe even with three degrees of freedom per leg — but for now, it’s a 2DOF quaduped. Once it’s walking reasonably smoothly and efficiently, the plan is to make it remotely controllable and embed a video camera — probably using XBeePro modules (from SparkFun, where else?).

The version in this video is still based on a cutaway plastic project box; it has since been moved to a proper chassis produced on the 3D printer. This doesn’t yet do much for the gait, though.

More about the robot as the design evolves…

Posted in Coding, Digital, PIC Microcontrollers, Robotics, SIGMA Walking Robot | Leave a comment

The end of an era

Posted on 2009-06-12 by M. Eric Carr

TV in the US goes digital today.

As someone who has seen firsthand the magic that the Digital Revolution has brought us, I know that this is a Good Thing(tm). As a card-carrying Paleotechnologist (not to mention child of the 70’s), though, I can’t help feeling a little nostalgic for good old analog TV.

TV was simpler then — in Northern Virginia, our TV choices were channels 4, 5, 7, 9, 20, and 26 (plus some UHF channels if we aimed the antenna just right and occasionally channel 3 from Richmond if we aimed the antenna right *and* the moon was in the seventh house yadda yadda.)

Not better, mind you — just simpler. Paleotechnologist or no, I still wouldn’t give up our age of TiVo, YouTube, Hulu, DVDs, and flat-panel screens — even if the 70s did have better music.

Loran is probably next. They already did away with Omega, and with the Galileo navigation system coming online, there will be an alternative to GPS.

At least we technological dinosaurs will have our memories — from watching Sesame Street on a 1975 Ford TV (which I still have and which still works!), to navigating from Norfolk to Milwaukee and back with a Compaq Plus suitcase computer and a Loran-C receiver (GPS was for rich folks back then.)

Posted in Digital, Nostalgia | 2 Comments

Quadrupedal locomotion

Posted on 2009-05-09 by M. Eric Carr

Okay, this is unexpected.

I mean, I like old technology and all, but why would an electronics geek — even a Paleotechnologist — be reading a 127-year-old book on The Horse in Motion (with a study on quadrupedal locomotion?)

For a while now, inspired by some cool videos, I’ve been playing with the idea of creating a quadruped robot. The low-level stuff is pretty straightforward; stick a bunch of servos together, connect them with some brackets (3D printers and Google SketchUp are a dangerous combination — more on this later), and control the positions using pulse-width modulation. No problem.

The hard part turns out to be figuring out what joints to move, where, how, fast, and when — especially since the cheap S3003 servos I’m using are not the strongest things in the world.

What I really need is a good automated Physics sim (I’m looking into using Havok, but it’s nontrivial) that I could hitch to a Genetic Algorithm to figure out what gaits work best. The GA part I could do; tying it all in to Havok or a similar simulation may take a while.

Posted in Coding, Digital, Robotics, SIGMA Walking Robot | 1 Comment

Redefining the word innovative…

Posted on 2009-05-06 by M. Eric Carr

Take a look at the work of Theo Jansen. This guy is a paleotech artist par excellence — creating animal-like mechs out of hollow pipes, bottles, and plastic tubing. His “strandbeests” (“beach creatures”) are fascinating; he claims to have actually reinvented the wheel with the unique motion scheme they use — and he might be right.

The really interesting part, for me (and probably the reason why the strandbeests’ motion looks so natural and fluid), is that Jansen uses a genetic algorithm to design these creations.

His eventual goal is to have the ‘beests roam the beaches of Holland, living off of the wind and using their simple mechanical nervous systems to avoid dangers such as the ocean surf, dry sand, and storms.

I came across his work this evening while judging some student projects built for a freshman Engineering Technology course. One of the projects used a walker mechanism based on Jansen’s work.
Kids these days(!)

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