Robert sent over news about his new robot, LHEX. Check out the video below.

From Robert: "There are no operational sensors other than the encoders, but work is in progress. The bot has tilt and compass from mindsensors that will direct and help the bot. The idea is that this bot will learn how to 'best' walk using acceleration & tilt readings. The server master was a challenge (comms speed wise) but after many hours I managed to get both sides talking at the speed i needed (30ms). Programing is being done in labview with NXT toolkit You'll notice it is based on RHEX."


Sweet... it looks very familiar to the "cockroach" robot made by DARPA which was shown at the First World Festival this year. Anyone remember that?

Anonymous said…
I don't really understand the concept behind this robot... it is a walker, correct? And yet it moves its "legs" as if they were wheels. Can someone explain this robot?
Kirk Backstrom said…

I'm guessing the main concept behind the walker is for it to keeping moving forward. If the robot gets stuck, then it will keep changing the pattern of its leg's motion until the robot moves forward again. Hence the legs do not move in any set pattern.

Its legs are curved so that when the robot adjusts its pattern of walking, the legs always can remain in contact with the ground (or what ever it's climbing over) and not lose its footing, hence remain standing up-right.

One could say that the legs are a hybrid between legs and wheels, as the legs function much like wheels.

I hope that helps.

Anonymous said…
The legs are kind of like wheels but the shape is more of a half egg. If you do a youtube search on RHEX you'll understand what this kind of setup can do. Kirk is correct in the basic concept, the dynamics of the legs are based on a cockroaches contact pattern - I only have the basic forward pattern going at the moment but the climbing and descending patterns need to be much more dynamic, I am sure that this baby will be able to climb standard stairs when I get the power distribution correct. They may seem to act like wheels but I promise you getting it to a stage where it can walk was a real challenge as you need to make contact at all times with a tripod pattern and with two NXts controlling 6 legs this is not as easy as it would sound. I am well pleased so far wit the NXT sets are performing very well for the time and cost in comparison to the RHEX that must of cost a factor of 40+

Anonymous said…
I looked at the video a couple of times, and the "legs" appear to be a hex wheel with one side missing. The shape allows it to move in a very unique and interesting way. Hope to see more of this design, and hopefully some pics and (maybe) instructions.
Anonymous said…
this is impressive and nicely built.

however I wonder why it takes 6 motos instead of just two... since the 3 "whegs" on each side could be geared together...

do you know any lighter implementation of RHEX in Lego ?

Regards, Thierry.

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