Feb 28, 2009

Ogre; a color-coordinated NXT "tank"

Most of the times my creations are poorly color-coordinated; I just use whatever parts I need functionally and don't worry about how it looks. But with the black NXT (in other words, with an option), I started thinking more about how to utilize the color. While I like the white/gray color scheme, the darker pallet had me thinking more along the lines of a zamor shooter... and I already had the mechanism, and enough dark studless parts...

Thus was born Ogre:



The four zamor launchers can fire a little over 9 balls each second, with a large "tray" on the top that feeds about 50 of them and allows for easy reloading. The tank treads have the upper point of the triangle "sprung"... the tension on the tread is maintained by a LEGO shock, so that the treads do not have any slack in them (and when going over a bump, the treads can "stretch" slightly to compensate). It doesn't use any NXT motors (after all, they didn't go with the color scheme), instead driving the treads and the launcher using the PF XL motors. This gives it a nice easy way to run it as well: with the NXT off, Ogre can be remote controlled using two stock PF remotes. But turn on the black NXT, and it can control the entire vehicle using the Hitechnic IRLink, in a fully autonomous mode where it can "hunt" for isolated targets, center on them, and then launch a volley of spheres while advancing towards the target (and disengaging when the target is no longer present). Another fun aspect is a small spy cam mounted to one side. With that, both remote control an dautonomous modes are a lot more fun as you "ride along" on Ogre as it roams across the countryside. Or, well, the living room.

Originally I wasn't sure of the black NXT. And for functionality, after all, a regular NXT does have the same feature set. But after playing around with it, it has given me some ideas for different color schemes, something that has always been rather lacking before: after all, the RCX had just one color (one I liked, but still... only one).

--
Brian Davis

15 comments:

Michael said...

Wow! I am very impressed, both by the construction of it and the programming. Will you be posting that on NXTLog or any other site? I'd love to look at some pictures of it. Congrats on the black NXT, I'll be looking for other black creations:)

BlueToothKiwi said...

That is got to be one of the most evil robot I seen.... and I mean that in a nice way.

Thanks for sharing a very entertaining video

Ti0mma said...

Wow, this is amazing! Can you send me instructions? :)

dilip said...

very nice. and the look is amazing too.
can you use the camera to scan for targets instead of the US sensor? then i could identify colors(friends and enemies).

Brian Davis said...

No problem. Here, the black NXT just blends right in to the color scheme, and makes it look much more menacing (I did actually try a version in off-white/gray, but it really didn't have the same "feel"). Something I was pleasantly surprised by is the sounds it makes during firing; slowed down they sound even better, and I was amazed when I first video test in slow motion how it looked and sounded.

Clgfive said...

Wow! This is the best robot i've seen in a while! Very nice colors, great functionality, and perfect use of IR Link. I also have a question: what are those balls and firing thing, and where do I get them. Also, is the black the only differnece in the two NXTs? Lastly, is the brick the only thing that comes with the Black NXT? PS I hope you don't mind me sharing this in my blog, it's exceptional and I'll obviously give you credit.

Jim Kelly said...

Ah, yes... the ongoing war between robot and cats. When will it end? How long can these conflicts be endured by either side?

Brian Davis said...

To be honest, the cats pretty much ignore it, even if they are hit by one of the sphere (and no, I *don't* target the cats on purpose, but they have walked right through the field of fire on more than one occasion). However, they love chasing the spheres as they fly out, or batting them around afterward.

In the long run, I suspect that the cat/robot war will be resolved when the cats start developing robots against us. I keep the NXTs carefully separated from our cats, just in case...

NXTFreak said...

Quite an impressive robot! And it actually has a color scheme! Amazing... Also, your zamor sphere system seems very reliable and strong; nice job. I would love to know more about your tread "sprung" system. I too have those treads, and have the same problem: the treads are always too loose. They need to be a little bit more taught. How did you go about this with springs? Do you by chance have any "up-close" pictures of your tread system so that I can perhaps use it in some of my robots? Well, thanks for showing us Ogre. I certainly enjoyed watching the video. Have a nice day, NXTFreak

Matthias Paul Scholz said...

Brian,

What an impressive beast!

/MP

By the way, I suppose the real menace for mankind is the cats teaming up with the robots against us in the end ... ;)
On the other hand, the cats don't need to - they rule us already anyway. :)

Dave Parker said...

Excellent Brian! Now you need to make a street sweeper or Zamboni to clean up!

But my money's on the cats:
Diet: 100% protein
Immune System: Can drink pond water and eat rotting animals and only get stronger from it.
General Design Goals: Walking weapon
Stealth: Silent to sound sensor and virtually invisible to ultrasonic sensor
Hearing: Can hear NXT motors from probably 1 mile away
Vision: Well beyond useful ambient light threshold of light sensor, and, er, a little more than than 1 pixel.
Allies: Has human race well-trained to serve them.
Boot-up Time: Sleeping to chop-licking victory in 0.5 seconds.
Speed: By the time it triggers the touch sensor, it's way too late.

Brian Davis said...

Fatal flaw: an entire cat army can be disabled by a warm patch of sunlight or a single laser pointer.

The robots may have a chance... :)

Dave Parker said...

Organization and motivation are sometimes problems... However, EDS is working on a solution:

http://www.youtube.com/watch?v=Pk7yqlTMvp8

Brian Davis said...

Ti0mma: I don't have any directions for this (at some point, I'll take it apart completely and document it that way, but it's too much fun at the moment). But the essential bits of the Hailstorm launcher are up on NXTlog in an LDD file, so at least the "weapon" is well-documented.

dilip: I could use a camera, but (a) I don't have one, and (b) it's still difficult to get it to reconize a "target" this way, given the variety of colors in the background, the different shapes, etc. Not impossible, but not within the hardware solutions I currently have available.

Clgfive: blog away - we put this stuff out there for public consumption. The balls are called "Zamor spheres", and they have a couple of different style launchers - the older one (the looks a little like a three-fingered hand) is much easier to use in a robot. You could probably get them off Bricklink or something similar, although they are in some of the recent Bionicle sets (but you have to look carefully to see which type of launcher you are getting). The Black NXT is the same as a regular NXT "under the hood", and I think the package only comes with the Black NXT and some special media - not a bunch of LEGO parts.

And on a completely separate subject... Ill never be able to say "herding cats" with a straight face again. Thanks, Dave :).

jammalamma said...

awesomeness!!! i wish i had one...where do you get those zamor shooter things? ive never seen them before

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