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Building A Homebrew Robotic Lawnmower?
mmonkey writes "With the seemingly small amount of summer we get here in the UK, the last thing I want to be doing on a sunny day is mow the lawn. So I started thinking "surely a light-ish lawnmower could 'gain' a couple of motors, and suddenly be computer-controlled?". Then I started thinking about stuff like obstacle avoidance, optimum path planning, guidance system, how to get pretty-looking stripes, and I realised that it's actually a potentially complex (read: fun) thing to do. So, have any Slashdotters done this before? Did you modify an existing lawnmower or build a whole new one from scratch? What motors work best? For that matter, what type of mower works best? I know you can already get these, but that detracts from both my geek-drive and my wallet, both of which I'd prefer to keep as full as possible."
I'd make sure its plenty safe. I'm not concerned about you, but picture a mis-programmed robotic lawnmower chasing the neighbors dog, or worse, trying to run over a child... :|
If you know what objects are fixed,such as pathways, bird feeders, what-not, you could build the controller from one of those old dump trucks from the 80's that let you pre-program a course by feet and angle of turn, etc. All you need to add is a bar attached to a kill switch for when the neighbors cat/kid/dog runs over to check it out.
If you are one in a million, then there are six thousand people who are just like you.
this is off-topic, but you could ask the neighbours kids, they usually will do it for a couple of quid.
not very popular over there but many people do that over here in n.america
even in the long-run would be cheaper than a robot solution (unless this is a personal interest i wouldn't go ahead with it)
Marge, get me your address book, 4 beers, and my conversation hat.
you don't want to spend an hour a week, 6-7 months out the year, mowing the lawn, but you're willing to spend a hundred or possibly several hundred hours building a lawn mowing robot?
Enjoy your summer.
How about a goat? Maybe a sheep? Set one of those bad boys loose and you'll have yourself a short lawn. Obstacle avoidance and everything built right in.
How about some duct tape job of roomba and a lawn mower ? You get obstacle avoidance and area coverage for free. You can even come up with interesting names like "Rower" or "Moomba" :^)
uh oh...
I have something in common with Stephen Hawking...
Here's my most important suggestion - while you're testing this thing out, make sure you have a good kill switch.
Personally I dont think this thing would ever be considered safe enough to operate unsupervised. It might save you some work, but if it went out of control or some passerby tried to tamper with it you could end up with a very expensive lawsuit. (IANAL)
Make sure to code-in police avoidance for when your unattended lawnmower runs over your neighbor's feet while he sleeps in his lawn chair. On the bright side, you might end up with fewer cats hanging around the yard...
The University of Florida's Machine Intelligence Lab did the research 7-10 years ago. http://mil.ufl.edu/
This is no Roomba. Remember, the difference between a lawn mower and a vacuum cleaner is the *sharp* blades!
Try the vacuum first and when your design works flawlessly, move on to the lawnmower.
I mean they'll be staring at the mower and trying to screw around with it anyway, the least I could do is plug in a quickcam to recognize the critters and throttle over their toes or something.
I've had old folks bitch at me for going through their lawns when I was a kid...now it's my turn! As a geek, though, I bet we can do a whole lot more than yell "get off my lawn you good-fer-nuthin..."
...the sunny days during your short summer. To correct this, you will spend time indoors hacking away and making a homebrew robotic lawnmower.
The best part will be you will have perfected it by the end of August.
My first reaction was, "Well, you linked to what looks like a small business site, so either that site's going down or the hosting fees with bankrupt the company". But I digress.
that detracts from both my geek-drive and my wallet, both of which I'd prefer to keep as full as possible."
Well, I think your wallet's going to be drained either way. You need specialized components, software, etc for a completely automated solution. And even that's not going to be the end-all (corners, adjacent to fences, etc)
I would say start with a remote-controlled (as opposed to computer-controlled; mods, there is a difference) solution, see if you can rip apart some RC Cars, take their steering equipment out, see if you can interface to them using a RC Helicopter Remote or RC Airplane Remotes, connect up the servos, and perhaps sprinkle some detectors around your lawn.
Computer controlled would be difficult, to say the least. Perhaps even a Masters level thesis or a really good undergraduate senior project. Hell, if you can make it fairly cheap and efficient, you have your own business.
The best machine for cutting the grass is available in your neighborhood for a reasonable hourly fee. There may even be one around the house you can make do the job for nothing.
So, let me get this straight ... your solution to avoid an afternoon of mowing the lawn is to spend several months automating your lawn mower?? Sweet.
Skiers and Riders -- http://www.snowjournal.com
because it's tougher to build a beowulf cluster out of mexicans.
Have you considered artificial grass? It comes in a variety of colors and never needs mowing. Mine is "Misty River Green". With the optional circulated brine heating system, you can have a lush green lawn all year around, even when your neighbors' lawns are covered in snow. I recommend GrassCo brand Artificial Lawn Carpeting with its realistic texture and patented Flow-Thru (TM) drainage system. As a homeowner and lawn care enthusiast, I can assure you, GrassCo brand artificial turf is the only way to go.
Unknown host pong.
Back before everyone had the internet Popular Electronics (or one such magazine) had a couple articles on this. Lookup it up in the library, you did get the skills of searching in school, didn't you? They operated on batteries, but you could do whatever so long as your managed to power your computer.
The idea was a bunch of sensors, made up of LED senders and receivers. Mow a path around the yard, plus around any trees, and then turn the mower on. It should attempt to keep 2 sensors out of grass, and the rest (~20) in the grass.
BTW, mini-itx boards now have 12 volt power inputs, so things should be easier in many respects.
Materials: (1) Self Propelled Lawn Mower
(1) long rope
(1) stake
Step 1: Plant stake in yard
Step 2: Tie rope to stake
Step 3: Tie other end of rope to lawn mower
Step 4: Start mower.
Try looking at something like this:
x .s html
http://ltilib.sourceforge.net/doc/homepage/inde
I think the kill switch should be completely seperate from the entire system though. That way if other things fail, the kill switch can still be hit and no matter what goes on with the rest of the system it still kills the power.
Eventually, once it's all done, tweak it to see how fast you can make it work. Then make it so it can use a set of waypoints. After all that's done, enter it in the DARPA Grand Challenge and judging by last years results, you might actually have a chance!
The greatest experience we can have is the mysterious.
- Albert Einstein
A friend's neighbour decided to build a ride on lawnmover. Problems arose when decided to take the mower for a test drive. The Blade guard was off and halfway through the test the seat collasped and he had to put his foot down. Needless to say he gets around really well on his new leg.
It sounded like you want to make it autonomous but I think you should just try to make it telerobotically controlled at first to get the kinks out of your hardware design, adding some H bridges, sensors, and a laptop later on. It might be safer to build onto a store bought mower with a clutch that can disengage the blade. That's uncommon though and you probably won't find one at a garage sale. So the cheapest and maybe safest route would be to make a mower using the weed whacker concept of a spinning spool of heavy nylon cord. If an accident happens at least you won't lose an arm.
Too bad you guys don't have Mexicans over there in the UK. Did you check Ebay to see what a good used Mexican is selling for? Even the used ones can mow lawns fairly well.
http://www.imdb.com/title/tt0099611/
You could get some ideas from this one.
Flamebait, perhaps. Troll, maybe. But how can it be redundant when *NOBODY* has mentioned Mexicans before, in either thread or story? Hey, editors: make sure the fuckwit who moderated this "Redundant" never gets to moderate again. Or, better, give him/her/it the Mexican citizenship!
Let this fine film be an instructional video for what could go horribly wrong.
baltar!!!! omg it's baltar!
My dad did this just to get a chuckle out of the neighbors:
1. Get out your self-propelled "push-style" mower.
2. Measure the cutting width
3. Place a post in the center of your yard that has a diameter equal to or less than the Cutting Width / pi.
4. Tie the inner wheel of the mower to a rope that is fixed on the post.
5. Start mower at edge of yard and as it winds itself around the post, it pulls itself inward toward the center.
6. When finished, trim the edges of the yard and you're done!
Easy cheesy, and it'll make your neighbors think you're bonkers!
AskSlashdot: Building a homebrew prosthetic foot?
If you really want to be different consider an autonomous swarm of mowing machines. The guts of a Roomba would be a good starting point! I'd like to see a self-organizing mesh network created by the mobile mowing agents.
Good luck - I'd love to see this when you're done!
Why not dismantle one of those robotic hoovers and attatch it to a black and decker flymo?
Electronic Music Made Using Linux http://soundcloud.com/polyp
...they already tried something like this, but with cars... DARPA. :)
And, well, it turned out a miserable failure. But good luck!
Brain Dead for the climactic final scene...
Yay me!
First, build the logic. Take an RC car and use it as a lawnmower simulator. Connect your steering/avoidance circuitry to the car and see if the car acts like you want a lawnmower to.
Weedkiller + Green paint. Mix. Apply.
Engineering is the art of compromise.
I know its a neat sounding project but you are totally missing out on the satisfaction of having your yard groomed to perfection by illegal immigrant labor. And for the cost of a robotic mower they weed,edge, sweep,fertilize,etc... every week for more than a year!
If something exists that does not need a creator (god) then why must the cosmos need one?
First, get yourself a couple of Lego Mindstorms kits (so you have all the motors ans sensors you might require), and work up a useful collision-avoidin/path-cutting bot in your living room. maybe put it on a big sheet of paper, arm it with a felt-tip-pen, and tweak it's path-cutting algorithms like that.
Then, if you want to do more complex things - IR rangefinding, ultrasonics etc. strap a PalmPilot, Zaurus or some other PDS with IR on it and feed the midstorms controller unit with instructions from that.
Once you have it more-or-less foolproof (and you will probably want to run a wire round the maximum extents of your lawn and have a hall-effect or similar sensor pick up on it and kill the mower if it breaches that boundary) - then you can think about attaching a proper mower body and blade to it.
Then you'll probably want to port the whole thing to an embedded Linux u-Controller, and sell it for enormous profits.
I gots ta ding a ding dang my dang a long ling long
There was an Autonomous Lawn Mower Competition going on earlier this month - saw it mentioned on robots.net
--The more you know, the less you know.
so surely what we should be suggesting is that he build robot sheep?
I've never considered mounting a home-brew fermentation unit on a mower. But I'm starting to like the idea.
"Who are in control, they are not in control of anything - they don't even control themselves!" - Glen Beck
The tech isn't there yet. There is something similar to this idea, it's a supposed "smart" floorvac called the Roomba which is just dumber than a pile of bricks. Not to say this is the leading technology in the field, but i'm fairly certain it's an indication as to where retail autonomics is at. Also remember the Darpa Project with autonomous ground vehicles, some of which, didn't even make it out the gate.
I hate to discourage your effort, but hey.. you get sun, you breathe fresh air not recycled by a case fan, and sweat off a few mountain dew pounds. It's a win-win situation!
Mow the lawn already!
-Your mom
... until I moved out.
"Derp de derp."
I've seen a lawnmower with the drive held down tied to a pole, and the lawnmower will go around and around, and after each turn, the radius of the circle gets shorter and shorter... not quite as geeky, but definately as effective.
Hi! I'm a signature virus! Copy me into your signature to help me spread!
Maybe you could attach a mower to one of these.
John Kerry is a Joke!
I have had great experences using these to controll other robot rigs. Plus, there easy to program and can take a hell of a beating. Go to: http://www.ifirobotics.com/products.htm
They make these gizmos to keep your dog inside the yard, called the invisible fence. You bury this wire in the ground, the dog wears a wired up collar, he gets close to the buried wire and gets a zap, turns away. That's the theory. I don't think it works all that well with dogs, but for another electrical thing it probably would.
So, you start with one of them. That will keep your mower inside the designated area wherever you bury the wire. The mower part is an electric self propelled mower, They make them, you buy one of them. You'll have to make all 4 wheels drive so they can be individually activated for steering. Take the steel blade off, replace it with a string trimmer head, they are lighter, work about as good, and safer somewhat, and give you longer range on a battery charge. Now how to make it bounce off the obstacles and go in another random direction you got me, but I've seen several different cheap toys do it, so that tech has to be out there as well. You would have to add that into in the signal from the invisible fence to activate the turning mechanism, so you would get both kinds of turning, planned turning at the fence line, and random off of odd obstacles, like you sitting in your chair with a brewski or whatnot.. You turn the thing on, aim it out to the yard, let er go, it will randomly go around and trim, and being all electric, won't be all that loud, so you can run it a lot. If it consistently misses an area or two, just hand cut that part. Seems like the cheapest easiest way to go, but I am talking out my nether regions as well, might be a bear to make, no idea. I mow all day long mostly, or trim, or cut, or some other various chew up the jungle action, so I have thought of this many times, and can't think of anything heavy duty enough to do it on a big scale that wouldn't be dangerous as all get out for my purposes (one of the mowers I use will cut to almost 20 feet high and has about an 8 foot blade, so no way that could be a autonomous robot), so I've never tried to build one. But man, when it's 90+ F and near-equal humidity like it's been recently, I SURE HAVE thought about it...
Now a big female amazon warrior robot that you could task to drive the mower-among other things-now you're talking! And flyin cars!
%^)
Don't forget to add some evil Battlebot settings!
you ought to try mowing the eastern Oklahoma jungle, forget a high dollar riding lawnmower, tractors & brushhogs are fine if you just have a field or meadow and dont want or have trees.
where i live i prefer to keep my trees for shade, i wear out a gas powered push mower every 2 years...
Just copy the technology behind this one:
Robomow
. Ergo sum cogito - Yoda
Slashdot editor Pudge mentioned he uses a robotic mower in a recent journal entry. If you're too lazy to read it, the link to the mower is here http://www.robomower.com/robomo.htm.
How about having a remote control mode? so you can use it like an RC car.
I'd like a riding mower that you can train with GPS or something. After a few training sessions, you could let it go itself.
Collision avoidance is all and good, except when you have a pond...and when you collide with the water, well its too late.
http://www.robotshop.se/micro/wwwrc_us/indext.htm
robocut
Might be an interesting kit.
Oh, that's right. Forgot building robots is a Summer activity only. Oh well.
"What do you despise? By this are you truly known." --Princess Irulan, Manual of Muad'Dib
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from the replies thus far it seems to me that no visitors of slashdot have fenced in yards.
You may want to checkout the movie Maximum Overdrive. There's a great scene that shows how robot lawnmowers can improve our lives.
Have you ever used an electric razor? One pass won't do the job. Hell, three or four passes and you're still looking at a few stray hairs. Besides, in order to be remotely effective, the holes would need to be at least the size of a child's fingers.
the last thing I want to be doing on a sunny day is mow the lawn
But I'd LOVE to spend 3-5 months building an over-engineered gadget that, if it ever works, will probably require 10-30 hours of repair and maintenance per 1 hour of lawn mowing.
In the US, we find some kid, pay him $20, and be done with it.
(Hmmmm... Now if I could have a robotic weed-wacker... "Hey honey, I'll be in the garage!")
This one gang kept wanting me to join cause I'm pretty good with a bo staff.
It's a novel idea to brew up your own fuel for the mower (sugar + yeast), along with the alternative "trial runs with various liquors" when not brewing for mower fuel, but the alcohol content in homebrew beer just isn't enough to sustain an internal combustion engine.
"And we have seen and do testify that the Father sent the Son to be the Savior of the World" 1 John 4:14
Seriously, if you go ahead with this, don't use a regular metal mower blade. Use something like a weed whacker--a nylon string. Coverage is far less and speed is less, but speed shouldn't matter in this application. So what if it has to make 4x as many passes...
Real programmers use "copy con program.exe"
Basically all of the software development should be done on a smaller scale indoors. Because the actual size of the area to traverse does not matter. Not sure about lego mindstorms though, aren't they rather limited in their program complexity? I'd rather use Java or C++, or Perl.
What would be even more fun and probably bust your budget would be remote control via wifi, with a video link. Then you really could chase cats and dogs :)
...but I saw an article for homeowners a few months ago about mowing lawns. They said that if you have a typical lawn (ca. 1/2 acre), if you can get it done for During Spring Break, a lot of kids (usually jr. high or high school) go door-to-door trying to line up Summer gigs.
(Most of the kids are competing against teachers, who have plenty of time to earn money as well, although they usually form painting companies.)
Anyway, the kids usually think they want $45us or $50us, won't bag (even if we supply the bags), and often won't do trim work (even if we supply the trimmer) and they don't have a self-propelled machine, so they feel they have to charge more for the extra labor.
We've got a landscaper in the neighborhood who works in one of the other sections of our county (it's #2 in the "fastest-growing counties" - my wife hires him a lot too - easy for both of them. Anyway, one of his guys does the lawn for $25 on his way back to our neighborhood to pick up his vehicle. He uses a mulch blade, self-propelled machine and does the trim work. He does 1/2+ acre in a fairly short period of time.
Do I need a different way to have it automated? Not really. There's no worry about it running loose in the neighborhood (although having a good umbrella policy which includes excellent homeowner's coverage helps), etc. Anyway, for ca. $400us/year, I have no worries about getting it done and having done it for free at home growing up, I don't have to do it myself.
No spending on gas, you get fertilizer + milk + meat... I hate to see all these lawn mowers burning gas and doing something totally unnecessary... I am gonna buy myself a herd of cows, and wander around the town, offering lawn-mowing services.
Very easy, just get yourself a self propelled lawnmower, and one of those invisible fence systems, for keeping the dog in the yard. Tie the deadman switch wide open and let the mower be the dog and it's all set to use. Put those invisible fence dog collars on all the kids and dogs so they won't come in the yard and the mower won't leave and that's it. You could do the whole thing in less than an hour.
If you must moderate, please moderate as irrelevent, not something bad, because I'm sure someone will find this interest
I work for a company building a robotic lawnmower for commercial use. I'm in charge of software development. We have a few working proof-of-concept prototypes and are currently taking our design to production. I am in need of a skilled, dedicated embedded software engineer.
If you live in the southeast Michigan area, are interested, and possess several of the skills below, please contact me.
* fluent in C/C++
* embedded programming skills
* relational database experience
* controls theory, including optimal control, adaptive control, and state estimation
* CAN networking
* brushless motor control
* navigation and path planning
Regards
Bill
well probably not....now because i for one AM crazy i say first of all-NOT UNATTENDED...bad idea...now a remote control lawnmower would be cool... stick a couple wireless cameras on it, link the throttle to a servo and some kind of quick release for the stop lever....make sure the quick release is activated when(or if) the mower goes out of radio range... proximity sensors are easy enough to pull off, and if you were dedicated you could set it to stop the wheels when one was set off..... as for the drive mechanism, find a couple old electric wheelchairs and you are set...you are gona have to do some serious hacking with th lawnmower to get them to fit and to seal them off from all the dirt and grass which gets thrown by the lawnmower... i like the concept and almost built one myself, but realized that it would be incredibly stupid granted my yard is small =)
You should read an excellent book: "Flesh and Machines: How robots will change us". It is written by Rodney Brooks. His company (iRobot) was behind Roomba design. The book explains algorithms used in it.
Just have this guy come over and use his helicopter to do it. (long wmv, but well worth watching...make sure you watch long enough to see him set the thing down on the ground upside down.
If I was going to do this, I would start here (I've used their products for years).
. ht ml
http://www.tri-m.com/products/engineering/index
I would use the MZ104 CPU Board. They have a Linux distro you can throw on a DiskOnChip pop that in along with a regular old 64mb laptop SODIMM and you are good to go.
You can use the IR104 i/o board to provide 20 digital inputs and 20 digital outputs. This should allow you to hook up some simple sensors as well as giving you control capability. You may also need some sort of Analog I/O board, but I would avoid this for cost reasons.
The MZ104 CPU Board also has an I2C Bus interface with linux driver support. There are a plethera of different sensors available that you can directly read from this simple two wire bus.
These products are extremely affordable, rugged, low power and small. The entire system can run off of 5VDC. You can even lower the clock rate to save power.
If you do decide to go along with this, please add a wifi card and a web cam so we can watch it mow in real-time.... (uhhh oh slashdotted lawn mower)
You could obviously do this with something that had a lot less horse power, like an 8051, HC11 or Z80, but you would have to make up a lot of custom circuitry to get the job done. I like the modular nature of the PC/104 form factor. If you do opt for something with less power, I would definately make sure it has a built-in i2c controller.
Grrrrr... don't bother me, I'm thinking.
I made a simulated prototype of a fast/simple algorithm, which was 100x (IIRC) faster than random wandering in my tests. A bit of information is here.
It requires that the robot know its position rather accurately, but if it's a hobby you could use differential GPS (which would add too much to the cost of a low-end commercial robot). You might look into localisation via wifi.
Hire someone to mow your lawn! (Over there, "across the pond", do you say "rent somebody?" I ask that because you hire cars.)
Best Buy can have you arrested
Here in America, you tell them how cool it is to mow the lawn- and they can't do it, they're not cool enough. But, maybe- just maybe- if they pay you, you'll let them do it.
Now whitewash, that's a whole other story.
Please help metamoderate.
points to consider:
1. Make sure the robot does not take an interest in finding Sarah Conner.
2. Should you be enjoying a lazy day in the hammock while the mower does its job, and you hear some incidental music start up that sounds very 'AC/DC-ish', Get your sledgehammer or other non-complex machine based method of destruction ready.
3. Do not power the robot with alcohol. Take extra care not to power the robot with malt liquors such as 'Olde Fortran', lest your robot develope a penchant for petty theft.
4. klaatu barada nikto
5. Consider brushing up on Asimov's laws of robotics, just so's you get them right.
There are some people that if they don't know, you can't tell 'em.
> So, have any Slashdotters done this before? Did you modify an
:-)
> existing lawnmower or build a whole new one from scratch?
Naw, all that obstacle-avoidance and guidance is too much of a pain.
I was just thinking of something simple, like a robotic vacuum cleaner...
Pay $10 or so per week to get the neighbor's kid to mow my lawn. At least, he is somewhat reliable!
Coderz 4 Life
Who is going to that much trouble to build something that has no brain and just stands there?
If you must moderate, please moderate as irrelevent, not something bad, because I'm sure someone will find this interest
Comment removed based on user account deletion
In the late 80's I remember a series of articles in one of the "homebrew" electronics magazines (Electronics Monthly perhaps?) regarding just such a machine: a robotic lawnmower.
I've thought about it since then, but I can tell you what I remember.
The functional pieces (meaning the nasty cutting bits) were dual discs with small hooks mounted on swivels. There were three hooks (they were flat hooks, like mini-scythes) per disc, and they rotated in opposite directions. Centrifugal force would propel them outwards and I assume this was a "it won't bust itself on a rock" mechanism...
As for the self-mowing part, here's what you did. You had a memory bank and rudimentary control system. First you would manually drive it around the perimeter of your yard (and anything else you didn't want to get cut up), thus programming it with the borders of your area.
The rest I forget. Keep in mind we're talking late 80's-- crappy batteries, crummy microcontrollers, etc.
It was simple, but it looked like it would work. If I hadn't been a high school kid whose parents poo-pooed every cool idea I had (business ideas) then I'd have mass-produced the suckers and made a fortune by now!
Hope this helps!
did you win a free ipod? build a case for it here
"you will probably want to run a wire round the maximum extents of your lawn and have a hall-effect or similar sensor"
The commercially available robot lawnmowers use this. Lay the wire around the perimeter of your lawn and around obstacles like flowerbeds. It takes the guesswork out of edge detection.
Finally, a use for RFID that the /. crowd could like. You could put a reader in the mower and then put the tags around the edges at strategic points so the mower knows where it is. Then use an old iPaq (you can run Linux on them www.handhelds.org) or a mini-itx board with a little software logic and voila, instant mower. The software could be simple to, just a basic map program plus a series of vectors to tell it where to go. Hell, Logo with that turtle would be able to pull this off. Just some ideas for your mowing enjoyment.
:-p
Then again, a video camera with "grass recognition software" might be more fun.
Mike Scanlon
Have the laser mounted so that the grass height can be adjusted and then have the laser sweep the yard, cutting any pieces of grass longer than the pre-adjusted height.
Of course this will only work on a flat, small area.
You can take a modified version of this that will work in a fixed square area mounted on wheels. Have the robot move over the area that needs to be cut, settle the frame against the ground, for reference and then sweep the laser to cut. The robot can then get up and move to the next square area to be cut. Moving like this, you can cut the lawn in square areas. Cutting curved areas, however, will be a challenge.
with a 100-ft cord, I can do the whole yard. I love mowing the lawn. Yeah, I know I'm weird.
buy a goat. have it tethered to a stake. move the stake inna geek designed patern. you may have to disguise the beast as a dog depending on your zoning regs... end of summer, sell/slaughter said goat depending on your penchant for gyros.
Serenity now, insanity later.
Why would you want a robot to do this job? Lawn mowing is one of the truly great pleasures in life.
You like beer, right? Grab two or three or six and toss them in a cooler. You like music right? Grab some noise cancelling headphones and your stocked iPod. You like to tinker right? Take up small engine repair, and keep your mower running smooth and sharp.
Hop on your mower and roll, man.
-B
Make sure version 1 supports targeting the kittens playing on the lawn, with an error checking routine that will cause the mower to backup over the kitten if it doesn't do a good job on it the first time.
Anyone else remember that old set of screensavers on Win9x with the flying toasters and well, a lawn mower, a meadow, and a bunch of kittens *evil grin*?
That's an interesting idea, but I doubt you could get the grill fine enough to prevent fingers from entering without.
The underlying problem is the amount of kinetic energy you have in a spinning blade. The less kinetic energy, the safer. A spinning fishline is going to be safer than what amounts to a giant spinning knife.
Of course the reason you need the kinetic energy is so you can cut a lot of grass very quickly. With a conventional lawn mower, you can probably mow about a square meter or more per second. It cuts down on the drudgery time. But since the author is building a robot, drudgery is not an issue. So why not go slow?
I am imagining something that is very, very slow. Something that moves slowly from place to place gently cropping a tiny amount of grass at a time. In other words, an electric sheep (with apologies to Phillip K Dick). You'd calibrate the jaw strength so that it is enough to rip up a mouthful of grass easily, but not so strong it would sever a finger. You could get a nasty robot bite, but it wouldn't require a trip to the neurosurgeon.
I like the sheep idea because it leads off in more interesting directions. I'd think you'd run out of ideas for a robotized conventional mower. With the electric sheep, you can set a number of more interesting goals than having it walk a predetermined path. For starters, you could give your robot sheep a simple vision system so it could perceive the edge of your walk and touch up the edges. What would be interesting is to train it to visually recognize certain objects: it perhaps could recognize common lawn pests like dandelions or plantains and give them an extra close crop. Maybe it could retrieve the paper the paper boy threw onto the lawn and put it on your front porch. Maybe you could teach it to recognize beer cans and throw them in a recycling bin. You could make several of them and have a flock and begin to program them to interact in interesting ways.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
these guys work in the guidance and navigation laboratory at IIT, conveniently located down the hall from the wind tunnel lab where I work (hence my sig below). Beware though, designs such as this may inspire some sarcastic and mocking comments from the more machine shops techs who put it together for you.
a beowulf cluster of....well, nevermind..
Hello fertilizer! Anyone who lives in an area of the country where geese migrate can tell you that you probably won't want to go barefoot on your lawn for a while if you choose to keep geese there.
Don't forget to make sure it's not programmed to go back in time and kill your mother. She's not named Sarah Connor, is she?
Design for Use, not Construction!
...
Then I started thinking about stuff like obstacle avoidance, optimum path planning, guidance system, how to get pretty-looking stripes, and I realised that it's actually a potentially complex (read: fun) thing to do. By the time you get that thing built you'll need a bush hog to cut down the long grass.
So the first thing you want to do on a sunny day during your short summer is build a complex lawn mower? It sounds to me like a priority thing rather than a summer thing. I should insert a comment about "true geek" here, but this reference should suffice.
Take a look at thism ower.h tm
http://www.geocities.com/zs6bne/myrobotlawn
...helper monkey
I've thought about this a lot. If I were ever to do it, I would use a reel mower. Modern reel mowers have blades that don't touch, so they're easy to push. No engine means pollution free, and fewer parts to break. And with sealed bearings, maintenance would be virtually non-existant. Plus, your motor will not only provide propulsion but also the cutting power. I would try something like this: http://www.cleanairgardening.com/brilreelmowp.html
if this was that easy i doubt that they would have the DARPA challege Your not going to get anythign easily to do this. I recomend you take the time to do it yourself, it would be good exercise too. Sometimes there something to be said about doing things manually.
30% Troll, 50% Underrated, 10% Interesting
Score:5, Troll
If you could rig some sort of buried wire recognition system (magnetic?) you could have it follow a preset course that you could bury in the lawn yourself... (idea from the robomower site which alluded to something like that: " With the Rl1000 and the Docking Stations, it's even easier! After completing the one-time set-up of wire around the lawn including the Docking Station, set the weekly program and forget about mowing for the entire season! ")
a) get two|three|four big DC motors (gearing probably a good idea but you could probably find two large ones at a scrap yard somewhere)
b) get a breadboard and a micro (i recommend atmegas - chip is ~$5 + $9 for programmer + compiler (WinAVR) is free/opensource
c) get a 5v linear regulator, some optoisolators, and (easiest) get some cheap high-amp MOSFET's (remember that you can always put them in parallel for pretty much unlimited current)
d) get a pair of crappy linx RF serial modules (cheap, easy to set up)
e) use 9v battery for digital power supply. use the biggest possible lead acid for motor power supply
f) go nuts!
(if you dont know how to hook these up together, you should first experiment with simpler circuits. epanorama is a good source of info)
estimated cost: $60 + existing lawn mower
One of my dad's co-workers built himself a super-sized lawnmower. He welded a frame, added wheels, and mounted 3 old push lawnmowers. He tows the contraption behind his ATV.
I assume he had to do the detail work the old-fashioned way, but I'm told it mows wide-open spaces very quickly.
I have like two acres of grass to mow every week, so trust me, I've thought long and hard about ways to reduce my work.
I decided that I could even go all out and make it really precise; maybe something like GPS for setting approximate bounds for my yard, and then really low-power beacons to mark the edge of the yard.
I decided there were a few main things that would give me problems:
1.) You want your lawn to be straight lines. Things like the Roomba seem to just run around aimlessly until they hit something, then they take off in a new random direction. Your lawn would be the ugliest monstrosity on the street.
2.) Suppose your pet cat runs out in front of it?
3.) Will it crash into the 'ornamental' trees on my lawn? And if you're going to detect it, how do you know exactly how wide tree is? And how do you detect that there's a 3-foot-wide ring of mulch around the tree?
4.) Suppose the 'tree' you avoid is actually my dog running across the lawn. Are you going to constantly recalculate its position?
5.) Out in front, my lawn has a multilayer terrace thing going. How do you avoid driving driving right over the edge? (Like a three foot drop. I've almost gone over this on my ride-on mower a few times.)
6.) Do you know the *exact* bounds of my yard? I don't want strips out by the street where it decided it was getting too close, but I don't want a multi-car-pileup after my lawnmower charges into the street.
Anyway, it's probably possible to overcome these. The problem is that, unlike something like the Roomba, you've got sharp blades spinning at completely lethal speeds. If the Roomba goes haywire, you'll stand there and laugh. If the Lawnba (*please* don't call it that!) malfunctions, run. Fast.
It's really a question of how much faith you have in computers. And between my experience with Windows and Java, I don't have a lot.
________________________________________________
suwain_2
i don't mind mowing my 1/4 acre every five days in the summer months, but the damn leaves in the fall from all my mature oak and walnut trees take forever to corral and haul up to the top of the hill that is my backyard. i'd rather have a robotic leaf blower that would blow all that stuff into my neighbors' yards like during the day when they're at work.
Serenity now, insanity later.
That's pretty much the way it gets cut when I push my mower around anyway...
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
Hmmm, sheep runs on the grass it eats, nibbles all day and is not particularly noisy. Better still, unless it is a Ram, it's unlikely to chase the neighbors. :)
-All that is gold does not glitter - Tolkien
www.ra
I've had one for several years and it works VERY WELL. They even have newer models for big freakin yards (TM). Other than buying new batteries and blades every two years, this thing has been great, not to mention the looks on my neighbors faces when he's out there cutting the lawn.
.
They've also released a home vacumn cleaner, which is next up on my must purchase list. .
I know you can already get these, but that detracts from both my geek-drive and my wallet, both of which I'd prefer to keep as full as possible.
If you want to build one for fun or as a learning project, great, by all means go for it. But if you value your time at all, you're absolutely kidding yourself if you think you can build any kind of decent (read: safe and reliable) autonomous lawnmower for less than the price of a Friendly Robotics RL-1000 ($1800 at Amazon) much less the far cheaper RL-800 ($800) and RL-550 ($600) models.
Right off the bat, you have to consider how you're going to power this thing. Gas? Electric? Electric will be easier to instrument and control, of course, but you've got that pesky power cord to consider. Wouldn't want to run over that, do ya now? You don't have to worry about the cord if you go with a self-propelled gas mower, but steering is a hassle. It may also be a little more difficult to make sure you can stop the blade quickly as soon as you encounter a dangerous situation. Batteries give you the best of both worlds, of course... separate motors can drive the blade and each rear wheel, giving good control over the blade, decent propulsion, and steering. And you can use the batteries to power the electronics, too. Of course, batteries will also add to both cost and weight.
I predict that if you consider your time at any reasonable hourly rate, you'll find that getting to the point where you've got a robot that you can drive around the yard via remote control will cost you a LOT more than the top-of-the-line RL-1000.
Incidentally, building a remote-controlled lawnbot is probably a good way to go. Put just enough electronics on the bot itself to communicate with a mother ship and to shut down the machine at the first sign of danger, like when someone lifts it up. Something like a BASIC Stamp with a RF package would be a good, cheap way to go. That way, you can build a human-operated remote control for testing and such, and a computer-operated one when you get to that point.
Again, I'm not trying to dissuade you if you're into building such a thing for fun. Just make sure you're paranoid about safety, or it might not end up being so much fun. But if you want to keep your wallet full, either buy a ready-made version or (as someone else already said) pay the kid next door to mow for you.
Think of your lawnmower as a BattleBot. You've got a drive system (wheels) and a "weapon" (the blade). Okay, it's not the greatest analogy, but we're talking about components of the same caliber, and I know a little bit about this type of robotics.
:-P and has all the programming tools set up, ready to go, and designed almost specifically for robotic applications.
Building your mower from scratch would be something fun and geeky and not *too* difficult if you know how to weld and such. If you take this route, consider using battery power for the drive train and a small engine for the blade. I recommend electric power because it is easier to interface with a navigation computer and allows for easy reverse if you get stuck up against an obstacle. You could even use another electric motor for the blade. In any case, a good source of electric motors is NPC Robotics. They also have wheels you could use. I think a remote control system would be neat, even if you don't want to drive it around all the time. You could use it to guide the mower if it's "lost" or as an emergency shutoff from inside the house. A manual override feature would be cool to just drive it around for fun, too. Of course, this makes things expensive. But a neat way to do this would be to use an IFI Robotics Isaac 16. This system includes a radio and transmitter plus a BASIC Stamp computer that is easily programmable and allows the reading of 4 analog inputs and 8 digital inputs (sensors on the mower). This would allow you to have, for example, an "RC startup" button inside your house that would remotely trigger the mower to begin running, then use the programming features for automated mowing. It could be both RC and autonomous, really. With that system, you could use a couple of Victor 883 speed controllers to regulate your drive motors. There's also a spin controller that would be perfect for your blade if that were electric powered. Otherwise, a simple gas engine with a servo on the carburetor throttle would suffice for control of that.
If you don't choose to go with this (very expensive but neat) RC setup, you could use a much simpler BASIC Stamp. This is the "brain" of the Isaac 16, but minus the radio and PWM signal drivers (for speed controllers, servos, etc.). They run a lot cheaper ($150 for a basic setup) and are still very easy to program (a modified BASIC syntax) but you would have to wire your own interfaces to speed controllers. This can be done, but I have no experience with it. In any case, the BASIC Stamp would allow you to connect various types of sensors that you could use to gather data and then modify your path accordingly. The Stamp is probably a better choice than a Mini-ITX or similar because it is cheap, not overkill
So check some of that out. I hope that helps if you're looking to build something from scratch.
Oh yeah, if you're concerned about powering an electrical system for long enough to mow your lawn, a few 12 volt lead-acid batteries of the type used in motorcycles or smaller car ones will likely suffice. I believe they can deliver around 14 Amp-hours or so.
Beowulf Clusters dying! With the passing of escape key inventor and father of ASCII Bob Bemer, the character strings that power the terrible jokes are just too despondent to get up and go to work. Textual prozac sales have skyrocketed.
How about putting some inertial/vision systems on this puppy?
s p? &CATID=182628&PRODID=205388
http://www.diy.com/diy/jsp/bq/product/product.j
3 Gyros, 2 accelerometers, a well-tuned PID loop, a GPS unit with some way points, maybe an altimeter and you could mow your whole neighborhood's lawns...
That was supposed to be funny, I know it wont fly, but you could build something that would...(I'm working on it.. not a lawnmower) more later.
Here's what I'd recommend. It'll cost you about $10 per mow, but it's worlds easier than building your robomower.
I honestly would do the most simple thing, and create a PC controlled system.
eg, a daemon on your system would control a radio control and control the lawnmower like a RC car, or better yet, just control it yourself.
This is the most economic device I have ever seen and it is totally automatic. It seems that it can also detect grass by the flavor.i dkindur.h tm
http://www.ismennt.is/not/astridur/vefle
That perhaps leaving a small and valuble robot on your front lawn all day where less-then-respectable people can just grab it and walk away might be a poor idea?
I suppose you would build a larger version with the blades on the front to guard the smaller robot from would-be thieves though...
But that probably reintroduces the problem of it killing curious kids by mistake.
Don't automate or robotize anything as dangerous as a lawn mower.
No matter how safe you think it will be; the debug phase is deadly dangerous, and maintaining it in the face of entropy and growth in neighbor's use of devices that send signals (that could affect the behavior of your running lawnmower) spells danger.
Automate OTHER stuff !
1. Pick up phone
2. Call The Lawn Guy
3. ?
4. No profit
I would put a tilt sensor on there that will shut off the motor if a specified angle is reached. This will help preserve hands and feet of any kids who try and lift it up while it is on.
In other words, an electric sheep
mmm electric sheep.. now where's my magnetic gloves and kneepads?
Suchetha
learn from yesterday, plan for tomorrow, party tonight
or one out of three ain't bad
"a horde of drunken, psychotic Zen masters"
wow! that phrase just makes me smile!
You're too lazy to mow the fucking lawn but want to embark on a freaking engineering journey to solve a non-existing problem? You need help, friend, preferably in the form of a willing and sympathetic MOTOS.
When I read shit like this story, I really question the sanity of the so-called nerds, and I wonder if I shouldn't hand in my membership card. I mean Jesus H. Christ....
Pave the yard.
If it were me, I would forget about a gas engine and a spinning blade, and start with a set of electric hair clippers - the kind with a pair of bladed combs where one vibrates over the other, creating the same effect as about a dozen pairs of tiny scissors.
Grass is bigger than hair, so you'd need to replace the blades with larger ones - something on the scale of those on electric hedge trimmers, but maybe not that big.
Then attach it to a remote-control car - preferably one with big tires.
And change the power supply to a big solar panel and large capacitor. It will probably only be able to go several meters a day, depending on available sunlight (but this is a summertime-only device) but that should be adequate for a small lawn.
For the obstacle avoidance, you could use almost any simple robotics kit or plan to have it always turn left 90 when it hits an obstacle.
You certainly won't get a perfect lawn, but I would start with this as an inexpensive prototype first.
every stain tells a story
Homemade Radio-Controlled Lawn Mowers
Hybrid Remote Control Lawn Mower
Radio Control Lawnmower
Robo-Mower
// TODO: fix sig
Take a trip to the library. Look through the Popular Science magazines from 1967 && 1968. In one of the issues (I no longer remember which), there are details on how to build a 'robo-mower'. They called it something else, of course. It uses the same type of "fence" mentioned by 'zogger' previously, and when it finds the 'fence' it turns to mow in a different direction. :>D
The below is a review by New York Times from a couple of years copied from:
http://www.homebotics.com/Pages/review_Time s.htm
Pull Up a Lawn Chair and Watch the Robot Mow-the Grass
By MINDY SINK
ALTHOUGH many futurists have envisioned robots that could relieve humans of ordinary tasks like cooking and cleaning, people must still do most of the domestic drudge work, at least inside the house. But outdoors, the future is here. in the form of mow-bots.
One of these devices is the Robomower, designed by Friendly Robotics, whose United States office is in Abilene, Tex., can propel itself around the yard, cutting the grass and even turning the clippings into mulch, eliminating raking from the to-do list.
The Robomower Limited Edition Silver Classic has been on the market in Israel and Europe for about 18 months and in the United States since late last year. The latest model, the RL-500, costs $749 and will become available in the United States in June.
Robomower is not the only robotic lawnmower around. Husqvarna. a Swedish manufacturer, makes two robotic mowers, including one that was introduced in 1995 and runs on solar power.
Husqvarna's machines, called the Auto Mower and. the Solar Mower, cost $1,999 and $3,000, respectively. Installation- yes, installation -- Costs $250 to $300.
Each of these lawnmowers needs guidance from a wire that is installed around the perimeter of the yard; the wire is usually on the surface of the ground, but it can be buried a few inches underground. The mowers may be robotic, but they are not very smart. They need to be told where to go and where not to. Each mower contains sensors that detect signals from the wire and direct the machine to stay within the mowing area.
Even if the mowers do what they're told, they can have some trouble with hills and tight corners,
Although robotic mowers may appeal to anyone who needs to cut the grass, some people could benefit more than others from this hands-free approach.
"We have a lot of people who say, 'I have waited all my life for something like this,'" said John Bunton, products manager for Friendly Robotics. "People with allergies, disabilities, the elderly, people with heart disease -- for the first time, a lot of these people can maintain their own lawn."
Mr. Bunton said his company's machines, which use battery power for both propulsion and cutting, were environmentally friendly, with none of the air pollution and little of the noise of gas-powered mowers. He said that about 700 machines had been sold in the United States since December and that a few thousand had been sold
abroad in the past 18 months.
The machines from both companies look a lot like canister vacuum cleaners without hoses or attachments, The Robomower RL500 tips the scales at 71 pounds, including its rechargeable lead-acid batteries, while the Solar Mower from Husqvarna weighs only 16 pounds.
After the Robomower mows along the perimeter one or two times, it starts cutting from one side of the lawn to the other, moving over for each new path. The Solar Mower and Auto Mower turn whenever they reach the perimeter, cutting swaths of grass in angular patterns that are not repeated until all the grass is cut.
The original Robomower can work for three hours before its fixed battery must be recharged; the RL-500's battery, which can be removed for recharging, works for up to two and a half hours on one charge. Husqvarna has designed its mowers to
stay on the job, mowing small amounts at a time but mowing frequently.
A robot mower can be hazardous for children and small pets. "It is deceptively quiet for a power tool," Mr. Bunton said, "This has a large blade underneath it"
Although the mowers have proximity sensors so they can avoid large obstacles, the lawn must be cleared of objects, just as it would be for an ordinary mower, before a robotic mower begins work. "It's not going to go around and pick things up for you" Mr. Bunton said, "You
Consider setting up something to figure out your robot's relative position. You can figure out the position using three wireless signal emitters of some sort and math (trilateration).
From there, you could take your bot and walk around your lawn, pressing a button to mark a vertex for an inclusive or exclusive polygon. Basically paint where you want the bot to mow. All sorts of other pathfinding information can be input this way. With the polygons you could mark off any major obstructions, and leave minor obstructions (rocks or trees) to your sensors and pathfinding.
So, with the bot knowing the geometry of your lawn and its position, you could devise an algorithm to give it a clean cut.
At this point you'd have wireless communication at least partially figured out, so as your next challenge you could get a swarm of these bots to cooperate.
We used to have this flying lawnmower that my dad got back in the 60's. It had no wheels, just a fiber glass body, a motor and a blade. It flew on a cushion of air created from the blade spinning. It was called a Flymo 19 or something like that..
Jisho - A Japanese English German Russian French Dictionary for the rest of us.
I think I used that mower last weekend.
Use an ultraviolet laser to vaporize the grass. That was my thoughts when I thought about building a robomower... that and radio triangulation. Burns sure suck, but at least they don't break bones. I was all set to do this until I stared thinking about patents, lawsuits, and the rest of the red tape. Thats about the time i decided that america can suck my cock and forego all the fancy ideas I come up with. Ninety-seven percent efficient cooling/heating? fuck your patnent system. Electrostatic propulsion? Yeah, just as soon as lawyers are outlawed. I have no reason to innovate because in the state of america innovation leads to higher taxation. and legal fees. and paperwork that i don't give a flying fuck about. But other than that, I'd say use lasers to vaporize the grass. Not "safe" but safe enough.
I think this was back in his Dean Martin days. Probably 60's sometime.
They say the first thing to go is your penis. Well, it's either that or your brain. I forget which...
first you have to build a shrinking ray that your kids accidently get shrunk by......
Personally, I've found that the controllers made by Innovation First are excellent. They are straightforward to program in C (assembly for those sadistic people) and offer a ton of control (16 10 bit analog inputs, 16 pwm outputs, 16 digital in/outs). This would be a great choice for the control system...
Just as bad as the picture in your head...
LETS DECOMPOSE & ENJOY ASSEMBLING
No but one could upload some cool images to be cut into your lawn... Think Lawn Circles :) Hey if you can make it detailed enough.. You might even be able to make a good buck Mowing Things into peoples Lawns liek Happy Birthday ect.. or pictures (if you can get decent shading down pat...
:) could pay for itself in no time....
:)
Could take on a whole new idea..
Hmm... I better run to the patent office here
Who needs WiFi when we can have Packet Over Sheep! http://datacomm.org/PoS-InternetDraft.txt
With these innovations, you could employ someone to handle that shit.
Lasers are cool. What about a ridicoulous mirror system to just pan and refelect the beam around your yard? Less moving parsts. Ah hell, I'm too, uh, drunk for this. Burn your damn feet off at the ankle... worse if you pass out in the yard.
I dunnow, why did God make Mexicans?
I worked on this about a year and a half ago for my senior Computer Engineering project. It was a group of 4, and we actually made fairly good progress in a semester. The main holdup was that the guy in charge of getting the supplies took too long to order everything, so we didn't get enough construction/debugging time.
Here is the basic construction plan we had:
* Start with standard push mower
* Replace front tires with "shopping cart" style wheels that can turn as needed.
* Mount two windshield wiper (or other powerful 12v motor) on the back wheels to provide independent control and near-zero-turn radius.
* Mount car battery on for powering of above motors.
* Add bump sensors for detecting when front hits an obstacle (we built our own from surgical tubing and wire)
* Add sensors across front of mower to detect cut/uncut grass. We used a series of optical sensors mounted about 2 inches above the ground at the front of the motor.
* Wall sensor to detect when a wall (or other wall-like obstacle) is near the mower on the sides.
* Add tip sensor to determine when mower is not near-level (being turned over by small children or leprechauns)
* Program/mount FPGA to take in sensor inputs and control motors.
Our basic algorithm was to keep the far left grass sensors out of the tall grass, and keep the right sensors in the grass (varying speeds of motors turns the mower left or right). We theorized that you could edge around the area you wanted mowed, then put the mower stradling this line, turn it on, and it would circle around cutting in a spiral towards the middle. Triggering the bump sensor would cause it to reverse, and then try to follow the obstacles' edge until it found a grass edge to follow. It was getting fairly complex by the end of the semester, but worked pretty well based on our lab testes. Real world tests were not as great, but like I said earlier, we kinda ran out of time.
Here are some pics:
Top View
Side View
Pic Started mine about 11 years ago. The mechanical platform was a roboticized Toro 4hp mulcher using a permanent magnet motor driven backwards to generate power for two beefy wheel drive servos and the electronics. Fully autonomous. Narrow beam ultrasound sweeping the forward path for semi-coherent vision. No external environment markers used except where there aren't any objects to range off of for 20 odd feet. You walk it through the lawn once and it makes an internal map of the environment and the path you chose it to follow. Then, just plop it down and hit the start button next time. Works infinitely more efficiently than the commercial attempts at *cough* autonomous algorithms the crux of which is which way to turn after boffing into the perimeter wire or an obstacle. Rev. 2 is going to go battery-powered for safety and you'll have to "show' it where the charging station is. Wish I'd had money to take it commercial.
All the ones around our company do is "mow" the grass for the whole day. A lot more fun than a piece of metal as well.
The "law of comparative advantage" that is.
That's usually covered in Economics 101.
Only a fool will waste time building something which is already available as a mass-produced product.
Your lawn would look like it was cut by a horde of drunken, psychotic Zen masters competing over the same sand garden.
Dude, I'd pay extra for that.
Suburbia sameness gets tiring.
I am not a robot scientist, but I would think that if you were to get to the point of playing around with with mapping where the robot is at, you should probably set up 3 simple transponders that you can "ping" from the robot. This should be enough for you to get a pretty good idea of where you are at in the yard. You could possibly even cut it down to 2 transponders if you can differentiate between the two. This could also be useful for transmitting remote commands to the robot (eg: it looks like it's going to rain... back into the garage!)
Using a system like this could also help you determine when the robot gets stuck. If the wheels are turning and we're going nowhere, then save fuel and power down.
One could have some real fun with this stuff.
See here. [grin] ;)
Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
so how would one program this device to find kitten?
http://www.rec.ri.cmu.edu/projects/toro/toro.shtml
We have a Roomba at the Overbot shop. It's really dumb, doesn't clean well, gets tangled in wires, and gets stuck under tables with chairs. It's basically useless.
Just wondering if you have seen this page? http://robotshop.se/micro/wwwrc_us/indext.htm
wouldn't it be like, way easier and safer to just pay a neighborhood kid a small fee and have them do it for you? i agree mowing the lawn sucks, but it seems to me that making a homebrew robotic appliance with sharp splinning blades is a bad thing.
alternative: plastic grass (they have really realistic stuff these days), or japanese rock-garden instead of lawn.
Every boy wants a giant Robotic Lawnmower for a pal.
"Nothing is impossible for the man who refuses to listen to reason"
Swedish Robotshop (a Basic STAMP reseller) toyed around with this idea for a few years. Expensive to buy as a DIY-kit, but great for inspiration! (http://www.robotshop.se/micro/wwwrc/indext.htm)
I have been looking at the types found at friendly robotics and the way they have things going is pretty slick. It simple, and pretty efficient.
They employ a mulching style blade that minimizes the size of the clippings, with the thought that they fall between the remaining blades and compost their way into lawn food.
There isn't much in the way of obstacle avoidance, instead obstacle redirection. Sensors on the front are depressed as it bumps into something, it turns and then moves on.
You define a perimeter of your cutting area with a 100m wire placed at the lawns edge. This wire provides a low power rf or some similar signal that the mower picks up on. If for some reason the wire breaks, the mower shuts down (blade spin time in 2 seconds). When the mower reaches the perimiter, it treats it like an obstacle, turns and mows on.
Finally, the mower runs for 3 hours (the big one of the three models). For 5 minutes prior to rolling off of the charging stand, there is an audible alarm warning of the mowers impenting departure. When the mower is closing in on the 3 hour mark, it starts heading back to the charger, charging time tales 24 hours.
So yeah, looking at these things... I would suggest some kind of 'remote control'. If the mower doesn't detect some sort of rf signal, it doesn't start rolling, allowing for a emergency shutoff. If you want to venture into the obstacle avoidance realm, perhaps hold off on that, get the obstacle redirection down first, then mod ify again, baby steps...
Some kind of charging system is in order... try for solar, or line power, I would steer clear of gas.
Would love to see any work you do on a project like this.
I don't know how or if this can be done in practice, but this is my idea. You could just lift up the turf, lay a thin, continuous (non-oxidizing) metallic strip along the path that you want the mower to take, put the turf back and fit some kind of metal-detecting sensor under the mower so that it will be guided by the metallic path now hidden under tha lawn. It will require you to clear the lawn of stuff like stones etc., but you'd have to do that anyway if you want a nice evenly striped lawn.
Why not buy one from Electrolux (http://www.automower.co.uk/) and see if you install Linux on it.
Have a look at http://www.solarmower.com/tech/frameset.htm Dave Mac
Any opinion expressed is also that of my employer - another benefit of being self-employed.
there was a magazine article with a project to build one of these in the late 1980s or very early 1990s. It was in something like Popular Electronics or one of the similar hobbyist project magazines of the time.
I was part of a team that created an automated mower demonstrated live on BBC TV's "Tomorrow's World" nearly 20 years ago!
That design had a Z80 to provide the brains, and various sensors to detect the edge of the lawn, for safety etc, including the emergency stop that the presenter showed *live* by putting her foot in front of the mower as it was running.
I think that I looked away assuming her foot would be cut off, since we'd told her it was a prototype and not to be trusted. Thank goodness our engineering was better than her judgement and the mower stopped as designed!
It was a modified rotary mower as I recall.
And no, I'm not going to include a link in this reply, because /. readers tend not to trust URLs with "goat" in them ;-)
When I am king, you will be first against the wall.
He has plenty of resources about a robotic lawnmover, and is an open project as well.
http://www.robotshop.nu
An open sour.. er.. joystick project should keep your lawn cut for a while. A web camera with a wi-fi link taped on top of a relatively simple wheel controllable cutter will provide fun for a lot of casual web surfers. Even a fan club with friends and foes (probably embracing couple of neighbors) fighting for directing/avoiding the sharp teeth toward/from your tulip garden and/or pet may evolve. The growing common intelligence of caring for your lawn is hard to beat wit any AI.
Theres a couple of complete kits out there. This one has a good programmable controller and remote that might make a good start. Granted, you couldn't use the chassis, but you could use the brains. In has a breadboard for (I think) another 8 digital inputs or outputs. It works well and should be adaptable for what you want to do.
Consider the problem of fitting an ashtray to a motorcycle. It may not seem directly relevant, but bear with me ..... it'll all make sense later.
The first, and most obvious problem is, how are you going to prevent the ash and nub-ends from blowing out all over the place? But even if you can sort that one out, then you have other problems to solve. Assuming you can make quite certain that bits of burning tobacco are going to stay well away from any inflammable fuel, then how do you put a cigarette between your lips while wearing a crash helmet -- never mind the non-trivial question of how to establish a burn and keep it alight in the equivalent of a 100km/h headwind. Assuming that you can manage workable solutions to those three problems, you still have yet another one: how are you supposed to wrap a Rizla paper around some tobacco, lick it and stick it, without taking your hands off the handlebars or your eyes off the road?
So, those motorcyclists who insist to smoke tend to stop and dismount; roll a cigarette, smoke it at a leisurely pace, perhaps engaging in polite conversation if they have been riding with a partner; trample the butt into the floor, and maybe take a leak before roaring off again. And that is why motorbikes don't have ashtrays.
Now, building a robot lawnmower is similar to fitting an ashtray on a motorcycle -- it sounds like a great idea at first, but there are just too many reasons, belonging to different domains, why it won't work. And the longer you think about it, the stupider the idea begins to look. For chuff's sake, if you really can't be bothered to cut your lawn, just pave over it! Or if you really must be high-tech about it, try and genetically engineer a slow-growing strain of grass that only needs cutting once or twice a year.
Je fume. Tu fumes. Nous fûmes!
I have also been pondering this for a while.
However I am leaning more towards a radio-controlled mower. This would reduce the complexities of an autonomous unit plus it'd be fun to drive (?). I am guessing that kit rc units could be modified easily enough.
But thanks for the post - some very good ideas coming out of this discussion!
Safety? Why? Did nobody see Battlebots? Now just make sure nobodyy enters your back yard and start experimenting. There is nothing better than a flamethrowing lawnmower on steroids, is there?
Hi Dude,
:-) then you should end up with a hazy circle defining the obstacle after a while.
:-)
Solar Power. Slow Moving. Goat Like. Hey if it is Goat Like, you can call is a GNU-mower. heh.
What you need:
A way for it to know where it is relative to the garden
OR a way for it to find out where it is relative to where it has been, and correct mistakes.
Either it should know preceisely where it is, or just remember how far it has gone, if it hits something, write it to a non-volitile memory.
if you garden has some GNOMES
You should plot all this in an appropriatle resolution, so 4 pixels is about the size of the mowers cutting region.
You should then make each pixel to about 8bits, and set a value for how long it has been since it went there.
You shoudl then process the bytes in a FOFI (yes FOFI) method, so it would contiuously loop.
Now to get stripes, just preset the grid with:
09a.
18bc
27ct
36de
45ef
It will process them as 0 1 2 3 4 5 6 7 8 9 0 a b c d e f etc.
thus going up and down.
it will write each area it goes through as it goes through that area. of cours eyou need enogh bits for the resolution syou are looking to for the lawn.
Solar Power!
Else pay a college student to mow your lawn, and wash you car, and get off on her 20 yo bod, whilst helping her education! That help one of your drives, and let me tell you, your pocket will feel kinda full!
You didn't hear that from me.
I would suggest you get in contact with the Fighting Robot Association who look after the interests of combat robot builders now that Robot Wars has finished. Their forum would be a good place to ask your question. We spend a lot of time discussing how to make combat robotics safer, and I think safety will be your first concern too, so please get in touch.
Thirty years ago, the parent of a friend wanted to solve the same problem before the days of small computers. He had a nice house by the river, with a big square lawn reaching down to the waters edge. He hammered a stake into the centre of the lawn, tied a rope to the it, and tied the other end to the mower. Jam the mower throttle open, and the mower goes round in ever-decreasing circles as the rope winds round the stake. It works, for a couple of orbits, so he goes into the house to get the camera to get evidence of his cleverness. Unfortunately, the rope provides a neat rocking pressure on the stake guaranteed to maximise its chances of pulling out of the ground. When he comes back with the camera, there is a nice neat mowed line leading to the water's edge, and a pair of mower handles sticking out of the water.
Consciousness is an illusion caused by an excess of self consciousness.
Just search for UDO on designforge
sometimes the low-tech approach is the best.
Bring on the minisheep!
I've seen a guy who mowed text into peoples lawns. Just simple letters, nothing special. I have no idea what kind of machine he had. He did not want strangers to see it (trade secret I suppouse).
I don't think he made much money. It was just some college dudes summer business.
I would never use blades in a robotic lawnmower: blades are way too dangerous! Nobody that I know uses lawnmowers with blades anymore, at least for a reasonable sized garden.
The lawnmower that I use do not use blades, but a nylon (or iron) string; the cord is rotated very very fast: this cuts weed and grass, but not trees and fingers (it will injure a limb, but not cut it). see picture The nylon cord is wind upon a small spinning cylinder : the downside is that you need to unwind a new piece of the cord from time to time (in particular if it touches a rock or any hard object), but I am told that newer models would do this automatically. (actually, if you hit a rock with a blade lawnmower, I guess that the blade would be damaged too).
Sounds like one of my dream projects (one I would get to do only in my dreams). I want a robotic garden weeder. It has to be able to either keep track of its position to within a couple of centimeters on a 4 acre field or be able to recognize a variety of crops and differentiate them from weeds. It has to be able to work autonomously, returning to some base during the daytime for charging and operating at night when there are no human obstacles. The crops are grown in (approximately) straight rows to simplify the process. If it keeps track of its position, it would have to communicate with a central computer which would keep a table of crop locations (generated automatically by the planter or possibly stored later by using the weeder in a calibration/learning mode). One method of differentiating crops and weeds could be simply size of the plant. When using transplants, the crop is automatically the largest thing around by far, so any small emerging plants would simply be wiped out. Note that gardens are frequently rough ground, so the device has to be able to climb over rocks and sticks occasionally (especially here in New England). Also, location cannot be determined simply by wheel rotation. If weed plants are chewed up, the chewing device will hit rocks or at the minimum, abrasive soil. (Sometime it's not enough just to pull a weed out. If the weed is just laid on its side, it can re-root and will remain the same size as it was, so eventually it can become large enough to look like the crop if using size determinants). It has to cost less than $5K in prototype. If the safety issues could be addressed, there would be a market for something like this among home gardeners and small farms. Could be expanded later to recognize and destroy insect pests (differentiating them from beneficial insects). Automatic fertilizing would require some sort of hopper to store the fertilizer and would significantly increase the size and weight of the device. Weatherproof, of course.
apparently the rf fence is all over my local supermarket - all the carts have one wheel freeze up about 20 feet into the store... ingenious!
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
What are the blade alternatives?
Perhaps fishing line used in the same way a combine harvester works and, use a metal bar as the point of contact. As the mower goes over the grass, the grass would run up against the bar and any grass that's grown over the bar, would be chopped by the rotating fishing wires.
This would also be a great safety feature as any fingers that enter the underneath of the Robotic mower would be safe as the fishing line would snap.
I'm currently making one based on a 'Baja King' RC car, with a SNAP module (probably best to use small PC board these days) connected to an SD20 for servo control and a MAXIM A2D chip.
It has sonar on servos and bumpers on back and front, plus two Sharp IR sensors each mounted on two servos for more accurate ranging and some degree of object recognition. It also has a passive IR detector to recognise the presence ofhumans/animals.
The robot itself avoids pits and walls over 5 cm, and sends information back to a server using a WET-11. The server builds maps and does some localisation and high level task planning.
Once safe I plan to add a motor powered version of a push mower to do composting maintenance cutting.
However smart it is at navigating, it will be ultimately useless unless it can find its charging dock and charge itself without intervention.
I will post a URL when more complete
The following is a site that may help you build this robot. Using a palm pilot as the processing unit may be very helpful and inexpensive. http://www-2.cs.cmu.edu/~reshko/PILOT/ You could also create a computer model/map of your yard and simulate the AI in the model using bruit force to find the best possible path. That way the computer can figure much of the desired path out for you. Keep in mind the heights of various parts of the terrain... wouldn't want it to flip over and create a potential health hazard. Another option would be to place small inexpensive magnets in the ground to help the guidance system. You could detect these magnetic waves to see where to or not to mow (Sort of like the new "autopilot" cars they are working on in Calif.) I do not fully agree with the slow moving idea because the point is to get the job done quickly so you don't have to worry about what could go wrong (Peace of mind). Also, would you mulch or bag... If you bag, you will have to dispose of the clippings.
int main(void) {while(1) fork(); return 0;}
I remember reading an old magazine 60's("Radio Constructor") that featured a solution to this- a guy had a circular lawn & wanted to automatically mow it - how did he do it? Complex electronics? no. He put a large oil drum in the center, and attatched the petrol mower by a long rope with a lenth the radius of the circle, wound around the drum. The mower is started, and as it unwinds mows a spiral pattern - then mows another spiral coming in! Bloke goes and has beer, and comes back just in time to switch the mower off as it hits the center.
:-)
The diameter of the drum should be a bit less than the width of the mowers rotors..
Or, just buy a goat..
"You lied to me! There is a Swansea!"
You probably have fewer obstacles in a yard, and they probably move less frequently (trees and such rarely walk around). Just focusing on what path it would take (not propulsion or cutting or anything) you could set RF or whatever beacons around the perimeter of your lawn. Put the robot down at one corner, and have it programmed to stop when there's a barrier ahead of it, move it's body length to the side and procede in reverse.
Imagining a tree in the middle of your yard where you'd put a perimeter around, it would end up missing part of your lawn, but nothing huge, and it wouldn't constantly go over the same section of lawn.
Hold on a minute... I think he might be onto something. I studied a great deal of entomology and comparative animal behavior in my (useless) degrees in Biology and Environmental Science and the same principles that termites use to navigate can be applied to a robot mow-swarm and can probably get about as straight lines as I usually get when mowing.
Termites use pheromones to create trails to food sources. Read _Fuzzy Thinking_ by Bart Kosko for some ideas but I think it would be fairly easy to create a fuzzy controller that would compel robots to congregate but to repel each other when they got too close. Low power radio (1 meter range or so) should be sufficient to let the robots know where the others are. Bound your yard with an "electric fence" (buried electrical cable) to keep them from mowing the whole neighborhood and it should work... (Of course the devil is in the details.) Using a simple fuzzy mathematical model and tweaking the parameters should allow you to tune the robots to get straight lines, cool Mandelbrot-esque patterns or whatever. Probably the coolest part of the whole experiment is that your mow-swarm could actually surprise you and create patterns that you've never thought of, based on small deviations in their original placement on the yard.
Or maybe I sniffed too much formaldehyde in college...
One of my neighbors is a retired engineer. He already has an automatic lawnmowing system setup for his yard. He has a wooden pole in the center with a rope attached to the mower. He then starts the thing and walks away. As the rope wraps around the pole, the mower covers the lawn inward in a circle pattern.
Honestly, I have not paid much attention to the details. I think he may have a system in place to turn the thing off when it reaches the center, but if so I don't know how. I just notice the thing sometimes when I drive by. Of course, this system will hardly cover the entire yard, but I'm sure it gets the bulk of the job done.
I used to file medical insurance claims, and to my surprise I once found a medical diagnosis code (HCPCS) for "lawnmower accident". Most of the codes are stuff like leg fracture or lung cancer, etc, so that "lawnmower accident" looked strange. I guess it happens a lot. Now I foresee a new one coming: "robot lawn mower accident" .
Many years ago there was one called Mowbot. It had sensors to detect a buried wire at the edge of your property, something like those "invisible fence" gadgets for dogs. You could also lead it around on an electronic "leash" for fine control of trimming.
When running freely it would just bounce off the wires at a somewhat random angle. So, no neat stripes, and some "wasted" motion going over patches already cut, but eventually it would cover the whole area.
It used a big disc with four X-acto blades for the cutter. Very very sharp, but the single screw holding each would allow the blade to swing back mostly harmlessly should the Mowbot encounter a firm object such as your shoe.
There are a lot of good or at least interesting ideas in the Mowbot, and it's so old that any patents may have expired.
No, I never used one myself. Check _Popular Science_ back numbers for a writeup.
See also an old book, _Build Your Own Working Robot_, for some perhaps dated ideas on designing autonomous vehicles for the home.
Geese are bastard animals from hell.
On average 87 people are hospitalized from goose bites a year. They average 3 stiches a piece.
Geese are known to carry disease. They carry ticks and mites which transmit the bubonic plague. Their bites may transmit west nile disease. Touching a goose can give you ringworm.
When you are trying to feed them bread geese will hiss and attack because they deep and abiding hatred for humanity.
Goose waste can transmit bacterial infection via children or restraunt workers.
The average goose is addicted to several hard-core drugs. Geese have been known to mug old women. Geese go through unlocked cars hoping to steal things to feed their drug addiction. Geese will gang up to assault anyone they think is carrying bread. Geese love to crap on or eat anything they think you value. Geese will steal your girlfriend. Geese will jam their thumbs in your butt and then laugh like it was the wittiest joke ever.
If you see a goose coming down the street JUST TURN AROUND. WALK THE OTHER WAY. Abraham Lincoln, Marie Curie, and Marilon Monroe were killed by geese. There is evidence that Jack the Ripper was a goose. Some people say that JFK was killed by a goose. The Salem Witch Trials were started on testimony from a goose.
STUPID FREAKING GEESE I HATE THEM ALL.
This post could only have come from Adam
Being geeky is great, but you are in over your head if you are asking these basic questions. The mower itself is a simple, slow, electric device. The commercial versions operate like a Roomba whereas they do not follow a prescribed path, but run so often you cannot tell where it has NOT been. This is due to the fact that the devices low (and considerably safer)speed cutting device is only processing an eighth of an inch of grass at a time. The constant running of the machine in random patterns helps to satisfy both the needs of the lawn (low impact, mulching, etc) and the needs of the homeowner (the lawn always appears to stay the same height, no work, etc). The machine is kept 'in boundary' by RF. You can modify an underground dog fence kit (about $60) to provide you with a boundary. I also recommend: 1. An attitude kill switch so when the thing rolls onto it's back, it shuts down. 2. Bump sensors (on the Roomba) 3. A lightweight plastic deck 4. String Trimmer for the cutting (they make extremely high quality aftermarket string that is two orders of magnitude beeter than the stuff that comes with the trimmers) 5. A toe sensor for the curious neighbor kiddies. 6. Remote control 7. Warning flags - There is no precedent for a injury caused by a robotic lawnmower - YET I actually considered a project like this, then I realized how much time it was going to take. I calculated my time, the cost of the parts, the hit to my insurance, and the ill will of my neighbors and bought a big honkin tractor. I spend about twenty minutes cutting 1/2 an acre.
About a decade ago there was an article in the Radio Electronics magazine (not even sure if it's still being published!) containing schematics and assembly instructions for a robot lawn mower. Head to your library and search it out. Or, do some googling for radio electronics robot lawnmower.
Siggy Wiggy Figgy Tiggy a bana bo Biggy!
http://www.geocities.com/zs6bne/myrobotlawnmower.h tm
Hold on...
You want to be cooped up in the basement building a robot lawnmower instead of being out in the sun cutting grass on a beautiful summer day?
The geek is strong this one!
First, create a front-wheel drive vehicle capable of steering. Second, mount an old style motorless push mower (the kind that are tubes of blades with wheels on each side). Safer, Cheaper, Quieter, More efficient, less complicated. Could you ask for more?
I can count to 1023 on my hands. Ask me about #132.
seriously -- why waste money on gadgets that fail -- a goat will keep your lawn trim, eats weeds first and grass last. just like bikes are faster and more reliable than a segway.
regards,
j
I don't know much about the electronic bits, but I suggest finding a gas powered reel-type mower. It cuts better than a rotary blade type that's common and works better when the grass is short from regular cutting. You'd have to find a way to power the wheels though. I was thinking individual worm gear drive to the wheels for low RPM and high torque and zero turning radius.
-- After all is said and done, more is said than done.
I worked on this project a few years back and we had a fairly good working system when I left. The first two obstacle detection algorithms used two cameras and worked well enough that you almost didn't need a laser scanner. It used encoders and a nice GPS system for navigation. When I left they had cm level accuracy on fairways.
automated golf course mowing
Check out beam robotoics. They are simple robots with "natural" logic and locomotion. You could build a swarm of these critters with a boundry wire keeping them penned up. Actually kinda scary.
I haven't been doing it robotically, but I've been mowing the lawn in patterns for quite a while now. It looks a bit nicer, but annoys the neighbors since it looks a lot more fancy than their hack attempt to just get it done in the least amount of time possible. :-)
Now, if you're willing to do design patterns as a business and do it robotically, you might get a few bucks more than the kid down the block since you'd have something to sell to the rich folks.
--
I have no sig.
1. $20 Movie + Popcorn
$30 Dinner
$6.50 1 Case PBR, or whatever you like
2. Wait 69 months
3. Tell the little rug-rodent to get out there and do his part for the family.
This idea is not my personal, original material, incase you were wondering. I was very good at mowing lawns too, thank you very much, and the cat damn well learned to sleep up on the porch railing. He he he...
Simple, effective, but more expensive than the commercial solution if the kid wants to go to college.
Why do I have this? I don't smoke.
...until the neighbor's kids look for their lost football in your yard when the home-brew robotic mower is hard at work.
My lazy (smart) Uncle used to take a wheel rim welded to a post in the middle of the lawn with 100' of 1/4 cable attached to the rim and the other end attached to the riding mower . He would then put it in gear step off and retreat to the porch where a cold adult beverage awaited.
the steel cable wound up on the drun pulling the mower closer every time it went aroun . When it hit the center post an arm shut off the mower. Then all he had to do was trim
Diplomacy is the art of saying "Nice doggie" until you can find a rock. Will Rogers
If your yard is rectangular rather than circular or square...use two posts?
I think it would recognise grass plants, and trim them to the preset height (bit taller in the hollow please) and remove anything else - moss, daisies, fish (I live in Devon, it rains a bit).
Inside the house, no longer having to deal with as much gardening clothing, we would find the Laundroid, a development of the automatic washing machine and the artificial nose, which prowls the house making decisions about items of clothing, and carrying them out.
Moomba..I love it! Screw asimovs laws of robotics, lets get to the fun stuff. Build a DEFENSE SYSTEM into the thing! Fences and no trespassing signs are there for a reason. The last thing I want is for some 12 year old with technolust to run off with 200 man hours of labor.
I say pinchers of peril! Ok well, maybe a reasonably severe audible warning activated by the right sort of proximity sensor...but right after that definitely the pinchers of peril. I'd like to see my self propelled, electric powered, weed whacker armed, robotic mower chasing people around the yard.
Forget the dog, forget the owner,
BEWARE OF MOWER!
I find that for a task like this, motors from those "power wheels" vehicles (you know, those little motorized cars kids can drive around in) are the best way to go. They've got a good deal of torque, modest speed, and they're fairly easy to control: a pair of LMD18200s (from National I think?) will hold up just fine under this kind of load. These motors can be had surplus for like 8 dollars a piece if you remain vigilant. Even if an automated avoidance system is out of your league, you could get some walkie talkies and put you together a bitchin RC system for under 30 bucks, exempting the cost of your drive batteries. For those you could go a number of ways... I'm partial to electric wheelchair batteries, but those can get pricey new... a smaller car battery may be the best bet, wouldn't run you too much, and you could get an off the shelf charger for cheap.
Electric fences use the high voltage arc's to cut grass ect that touches the fence. Not a fast way to cut the grass, but might make for a safe blade. If it only arc's once every couple seconds you won't get fried.
Someone asks a sincere question, that's not out of bounds (Look around ye, Slashdot, see the banner? News for Nerds?!?!?), and all I see is humor and derision!
Buy a GOAT?!?!?! What is that?!?!?!
Excusing fetish humour, and obvious jibes (and there are *MANY*) the point of the exercise is not to revolutionize anything its to "play" with technology. Just like those folks who modify cars, build their own homes, or do whatever makes their boat float. Its about building it yourself so you learn from the experience.
Is he going to be the next Einstein? Maybe. But irregardless of the outcome I think it's cool to work on these projects.
How many of us have drooled over a homebuilt idea that turned out cool? If you didn't answer yes, you may need to change your homepage away from Slashdot! <BULLHORN> Sir! Step away from the computer and nobody gets hurt!</BULLHORN>
Explore, Invent, Enjoy, (Be Safe!)
So more power to ya man!
<SOAPBOX>
Now for constructive comment. You need to decide how expensive you want this thing to be. The more intelligent it is the more expensive it will be.
If you choose more expensive, powerful hardware (like mini-itx boards) then you will get more wiggle room to work around problems and flaws. If you choose more embedded hardware then you are going to do more coding and figuring to lock the hardware into doing what you want it do by design.
Myself I'd go for the mini-itx boards. You get reusable parts if the project goes astray. I've also seen a wireless RS232 bridge, but nowadays you could probably just hook it up with WiFi.
The biggest hurdle I see is handling the mapping and autonomous functionality. Making it stay within bounds all within a cost effective package. So in quick summary, some recommendations.
1: Choose reusable hardware. Don't buy one use embedded electronics, tend for reusable pieces like mini-itx, WiFi, standard batteries or modify and exhisting lawn mower. You can use these in other projects after you've worked through some prototypes. After several prototypes you may then decide to buy the pieces for a "finished" lawn moyer. Up to you.
2: Check with other groups, mailing lists, or local robot enthusiasts. You've probably heard it before but one of these folks may either have the idea/resource you need, or give you an idea where to go.
3: Design,Design,Design. Before you start tinkering you should have thought out 2-3 designs of how you want the system to work. Not talking 3D CAD drawings here, napkins will do, but if it doesn't look like it will work in theory, it won't work in practice.
4: Be clear to yourself why you are doing this. This is not a timesaver, this is not effective use of time. This is tinkering and a hobby. The pure joy of it. By the time you are done you will have no excuse for how you spent your time that will work for anybody (Wives, Neighbors, and Friends). You did it because you wanted to, any other reason you will only lead to humour and derision. That will make you regret the project and the time you've spent. Keep your humour about you.
Don't know why people have these attitudes but that's just the way we humans be. It's always easier/safer to doubt than to believe I guess.
Good hacking to you!
Note: I realize I did not directly answer his question but after looking through the highscores I wanted to step up with some answers/responses. I've not built one, but I've been looking at some similar projects myself. Hope my thoughts are helpful in some way.
"Don't fear death... fear not living..." -me
Sheep trim grass. Goats eat grass roots,(aka the expanding deserts in Africa due to goat herding)!
Insert Witty Remark Here ===>____________________________