Books like "Build Your Own All-Terrain Robot"?

Hi,
Just starting out in building a "serious" robot. The book "Build Your
Own All-Terrain Robot" looks like it might be interesting but it seems
covers a lot of stuff that I already have already developed on my own
(i.e. the video transmission, remote controll, software aspects etc) on
small test robots, but not so much about the elctrical aspects.
Anyone know of any other books that will cover these areas in more
depth? In particular I am interested in what sort of motors to use
(e.g. steppers/DC?, what sort of gearing will I need?, how much torque
is really needed?), power sources, control circuitry for the motor
control and so on.
To give you an idea of the sort of context I need for all of this, I am
looking to put together a fairly rugged robot for use outdoors (grass,
paving, mild inclines, uneven soil etc). Its main purpose will be to
carry a mini-itx motherboard (with associated storage and networking -
this is all sorted and is not the issue) and a few other things like a
webcam, gps and so on. I'm guessing that I am going to need some pretty
meaty motors and probably some large (12v 20+AH?) battery too. Battery
life needn't be extremely long, but I'm looking for at least 45mins to
an hour.
If anyone can recommend a decent book or two on this I'd be really thankful.
Regards,
Matt
Reply to
Matt Dibb
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I haven't seen the book, but I've chatted with the author Brad Graham a couple of times when he was active in the Yahoo robotics group. He's into things like custom bikes and teraring apart Buick differentials, home-based welding, and other related stuff. From what I can see, he's not as much into the technical end of selecting motors based on torque, power, and what-not.
If you analyze the problem, though, I think you'll find some suitable books that cover what you need. They just go by different names. For example, Pete Miles and Tom Carroll wrote an excellent book on building combat robots that does discuss motors, batteries, control circuitry, and many of the topics you'd like covered, and for robots in the same weight/size class as the ones in Brad's book. Seems to me that an all-terrain robot is about the same as a combat robot, but without a weapon.
To answer your question regarding DC or stepper motors: A stepper motor would be inapporpriate for an outdoor robot on uneven terrain. You want a honking DC motor with a solid all-metal gearbox.
Finally, try to catch the eye of Jay Newman here. He's into building bots with Mini-ITX boards, and is familiar with many of the issues involved.
-- Gordon Author: Constructing Robot Bases, Robot Builder's Sourcebook, Robot Builder's Bonanza
Matt Dibb wrote: > Just starting out in building a "serious" robot. The book "Build Your > Own All-Terrain Robot" looks like it might be interesting but it seems > covers a lot of stuff that I already have already developed on my own > (i.e. the video transmission, remote controll, software aspects etc) on > small test robots, but not so much about the elctrical aspects. > > Anyone know of any other books that will cover these areas in more > depth? In particular I am interested in what sort of motors to use > (e.g. steppers/DC?, what sort of gearing will I need?, how much torque > is really needed?), power sources, control circuitry for the motor > control and so on. > > To give you an idea of the sort of context I need for all of this, I am > looking to put together a fairly rugged robot for use outdoors (grass, > paving, mild inclines, uneven soil etc). Its main purpose will be to > carry a mini-itx motherboard (with associated storage and networking - > this is all sorted and is not the issue) and a few other things like a > webcam, gps and so on. I'm guessing that I am going to need some pretty > meaty motors and probably some large (12v 20+AH?) battery too. Battery > life needn't be extremely long, but I'm looking for at least 45mins to > an hour. > > If anyone can recommend a decent book or two on this I'd be really thankful.
Reply to
Gordon McComb
Thanks Gordon.
I liked the All-Terain Robots book, and my next large bot will be based on a used motorized wheelchair I bought.
My only problem is that I can't weld.
The problem with combat robots is that they are built to run for about five minutes, which means they usually have oversized motors, undersized batteries, and are usually too low to the ground for my taste.
Though I've read most of the combat robot books to get an idea about how they were built. And the reading was worth it.
The Mini-ITX boards are very nice. I run Gentoo Linux on mine with a couple of CF cards as disks. I'm still working on building a good I/O processor. -- D. Jay Newman
Reply to
D. Jay Newman
Yes, one must extrapolate from the basic info that's in these books to build a general-purpose outdoor robot. Still, I think Pete and Tom do a good job in explaining how to calculate torque and power requirements for any motor, and they discuss the battery drain issue as well.
It's been a while since I read it, but I think Pete's book describes some basic measurements using wheelchair motors, which are basically going to be the standard for the average outdoor robot. When not re-wound to produce a higher speed (and higher curreent) I think most of these will function well for an all-terrain robot with a between-charge life of at least an hour. Otherwise they wouldn't be too useful as wheelchair motors...
NPC's site is a pretty good one for the basic parts, if you don't want to hunt arount. At $150-250 per motor I know I can't afford these (and they're rebuilds, from what I understand), but they seem pretty nice.
-- Gordon Author: Constructing Robot Bases, Robot Builder's Sourcebook, Robot Builder's Bonanza
Reply to
Gordon McComb
Diverse Electronic Services
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has wheelchair motors for about $100. They also have all the necessary electonics to drive them at reasonable prices. -- D. Jay Newman
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Reply to
D. Jay Newman
And somewhere around the time of 06/22/2004 17:02, the world stopped and listened as D. Jay Newman contributed the following to humanity:
Dumb question. What's a mini-ITX board? Is it some sort of SBC?
Reply to
Daniel Rudy
Its a fully function "mini" motherboard - rather like a shrunken down one you'll likely be able to find in a desktop PC. Benefits are that they are only 17cm by 17cm and generally consume on a very small amount of power.
They are pretty cute, but pretty expensive too. This page has some more information (and they also sell the boards too):
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also sell the boards. Note that the CPUs included may be rated at 1GHz, but their performance is equivalent to something like a 600 or 700Mhz Celeron in "real world" applications.
Matt
Reply to
Matt Dibb
A Mini-ITX board is a small PC motherboard form factor that is around 7.5 * 7.5 inches. VIA seems to be the main ones pushing these. They are a complete PC, with video, audio, and USB.
VIA makes most of them with low-power processors, some even for fanless operation.
You can see why these would be useful for robotics.
With the use of compact flash cards instead of hard-dirves the power consumption is minimal.
The next generation is the Nano-ITX form factor, which has a 4" *
4" footprint. -- D. Jay Newman
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Reply to
D. Jay Newman
Sounds very nice - do you know if any of these allow a single supply power input? The only major downside I can see to these boards is the ATX power supply with all those voltages.
The Nano-ITX board looks very nice. The photo I saw was not that great so I can't tell what kind of power connection it has. Maybe it just wants +5V :-)
-Brian
Reply to
Brian Dean
If you wanna see a complete overview of all available mini-itx maonboards, try this:
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Sascha
Reply to
Palle
There is a particular model that takes a single 12V input (it has an onboard DC-DC converter) which was designed for use in cars and so on, which I expect would be useful for robotics.
There are simple little DC-DC converters that plug directly into the ATX power socket which could be used also - the one that everyone seems to use/talk about is here:
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That uses a "nano-atx" power connector or something - not sure what the inputs are but it looks like it needs a "real" power suply rather than just a single input.
Matt
Reply to
Matt Dibb
Neither can I, so I use nuts, bolts, angle brackets, and other common hardware instead.
The gussetted plastic angle brackets sold on Gordon's website are lightweight and strong, and I'm finding more and more uses for them. They can even be used with no mounting hardware and no holes. Degrease the mating surfaces with rubbing alcohol, rough them up with sandpaper, and apply JB Weld (steel-filled epoxy). Wiggle the bracket as you push it firmly into place to ensure the epoxy gets into all the nooks and crannies. I used this a lot in a recent project, and the joints were strong enough to survive an accident which bent 1" x 1/8" aluminum angle.
Chris
Reply to
Chris Crochet
Neither can I, so I use nuts, bolts, angle brackets, and other common hardware instead.
The gussetted plastic angle brackets sold on Gordon's website are lightweight and strong, and I'm finding more and more uses for them. They can even be used with no mounting hardware and no holes. Degrease the mating surfaces with rubbing alcohol, rough them up with sandpaper, and apply JB Weld (steel-filled epoxy). Wiggle the bracket as you push it firmly into place to ensure the epoxy gets into all the nooks and crannies. I used this a lot in a recent project, and the joints were strong enough to survive an accident which bent 1" x 1/8" aluminum angle.
Chris
Reply to
Chris Crochet
DC-DC converter) which
Note that some of the 12-V to Mini-ITX power supplies are rated for 12V +/- 0.5V rather than "I stuck a lead-acid battery on this".
socket which could be
That one claims 12v +/- 15%, which is *much* nicer.
cheers, Rich
Reply to
Rich Walker

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