Tanto 2

[craig_anto]

I cant honestly say Im interested in putting on a weapon but Im sure me and Eddy will argue and Ill end up with some kind of weapon. Its gonna have spikes it that counts?
Traction control well Im not saying anything as too what Ive got in mind.
The angle is too steep? its 45 degree I think thats perfectly ok. When Tanto catches any edge on the wedge it tends to turn it over.

[matty_haka]

Craig, no I wasnt at Brighton! Seeing as Im only 14, getting anyone to drive me anywher is abot as easy as threading a piece of rope through the eye of a needle, so Iam impressed that you managed to throw something out the ring, though without seeming rude (It could in fact be a rare compliment! :wink I wonder whether it was the wedge that enabled that or the sheer brute force of the thing, aided by the shape!
As for a weapon, Why not have an Aggrobot3 Style wheel underneatth, that way you can raise the nose, and if it stops working, youve still got the wedge and brute force to carry you through.

Oh, and on a final note, is James the first person to become an advanced roboteer?! Congratulations if he is, and alos is ther a higher rank than that?!

[craig_anto]

just updated the tanto 2 bit
its not a good site i know but we do the best with what we have

[fluppet]

Thanks James. I was aware that maximum acceleration usually happens with some slippage, but hadnt seen it expressed in those terms before. I presume a fair bit can be done just by sticking a strain gauge on the driveshaft and seeing how much force you *should* be applying to it compared to the change in drive speed? Im a bit wary of the idea of predicting how much traction ought to be available allowing for heating/wearing tyres, fairy liquid and so on.

Other thoughts - can anything be done with the mechanism from an optical mouse to measure floor speed? (If some optics cant scale up, itd only help for antweights).

However, this is off-topic; perhaps a move to tip swa^H^H^H^H^H^H^Hhints and tips might be better if people want to discuss it further.

Several of my designs (sorry, vapour builder here) would benefit from having some intelligence on board; once the programmability is there I may as well add some engine management. :-)

(Speaking of which, whoever came up with the traction control for the Focus didnt presume that you want to accelerate if your wheels are spinning; kills the engine revs until youre out of the torque band, not helpful, better to balance the clutch and keep the revs - if not torque - high.)

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Fluppet

[fwsorg]

Andrew- Ive been playing with optical mouse technology for that very reason. It was useless at 20mph, but certainly for ants it would do fine. A small wheel with an odometer seems to be the best option.

[fluppet]

Cool - I look forward to seeing how well it works. I suspect the technique should scale up to higher weight/speeds if a bonus lens was stuck in front of the sensor (think fisheye), but that would be a bit fiddly to set up and might be too damage prone.

If you get it working on an antweight, Id be interested in giving it a go, though, if nobody else tries it first (or they do, and it works). Might be helpful in my plans for a self-built robotic vacuum cleaner, too (the ones you can buy cant do stairs, and I like a challenge).

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Fluppet

[jim]

Ive been looking at optical mice too, in fact I have obtained some code to interface a PS/2 optical mouse to a PIC, although I havent actually tried it yet. My research indicates that the highest speed they would work at is about 2mph. I would be interested to know how you get on with them.

[fwsorg]

I think traction control on an ant is a little bit silly :-) Would be fun tho. The prob with ants is that the weight limit isnt quite enough to stick in our own pic based circuits and PCBs, and start playing with things like that, unless youre willing to go down the SMT route which I most certainly am not :-)

[fwsorg]

Having said the above, I am now determined to build traction control for an ant The odometers from a ball mouse for the wheels, the optical sensor from another mouse for the real time feedback, and a PIC circit as small as i can get it, which will sit in-line between the Rx and servos (itll do the mixing as well). Im doing it to see if i can, not to win any competitions:-)

[fluppet]

I approve - and Ill watch out for it! Ive always thought robot combat should be about interesting designs, rather than the tried and tested. (Hence Im a fan of Tip Top, in spite of the drive mechanism blatantly being a bit of a daft idea.)

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Fluppet