Today I decided to post differently. Two videos from different authors in one single 'Week TechVideo' post.
Spiders and insects are quite different animals as we all know. In common there is the fact of them having multiple pairs of legs, unlike us humans which have one pair and most of other mammals which have two pairs.
If it is not easy to capture the several types of leg movement sequences from a 4-legged animal, it is incredible more difficult to understand real hexapod and octopod gait sequences.
You may find several good articles in the net about different types of gait, but they won't make it trivial their realization with a LEGO robot.
Spiders belong to the arachnids class and have 8 legs (4 pairs), and insects have 6 legs (3 pairs) among other well defined differences.
The realization of hexapod and octopod walker LEGO robots, is something that could go from relative simple implementations to quite complex ones. The result could be more or less effective but is almost always fascinating and difficult to achieve. Making this walkers turn is even more difficult.
On top of this, you may achieve really slow realizations or instead quite fast ones. It all depends on your skills.
Despite totally different in their complexity, approaches and solutions taken, I decided to post side-by-side two of the most impressive and actual LEGO walker realizations, of my preference (not to mention pure LEGO pneumatic realizations) - Respectively one 8 and one 6-legged, robots.
On the left side we have the "PF/NXT OMNI-Spider" by Menno Gorter (A Dutch AFOL) who has been building incredible LEGO walkers for decades.
Realize on how natural the movements look like, the legs placement are and how it is capable to walk in any direction, like a Killough Platform robot with omni-wheels.
The model here highlighted features a brilliant 8-legged spider, with four PF motors controlling them in pairs.
It is a preview from a prototype to display at Legoworld (Zwolle) starting next week. If it is a prototype, I would like to see how the final version will be. Hopefully we should get access to new videos soon.
Dammit if I understand the moving sequence of this legs... But we all know it was filmed to be not understood. Isn't it Menno?
On the right side a video for an "Hexapod Walker" by Gus Jansson.This six legged robot driven by 3 NXT motors (one for each two legs). Legs move in a boxy figure 8 pattern, and this I can understand much easier.
According to the author description at YT - "The left and right motors control their respective sides corner legs. The motor in the back controls the middle set of legs so that either left or right corner legs can be lifted. When left middle goes down, left corner legs go up and right middle goes up.
First program just walks in a simple pattern. The second program was for a walking robot race and uses the small LED lights as navigation aids. Light sensor, mounted in the back but looks forward, sees the light and with every step adjusts step size to aim for light."
Also the color schema used, is awesome!
Just in case you want to try something similar, you may find detailed pictures from this model, at Gus flickr stream (LEGO Hexapod Walker).