GAGA: Spinning blades, welding, wi-fi, what could possibly go wrong?

This topic was created by Bill Ray .

[Bill Ray]

GAGA: Spinning blades, welding, wi-fi, what could possibly go wrong?

Thoughts and ideas relating to the GAGA project to build an autonomous lawn mower, ideally before the grass gets completely out of hand.

[Nya]

Cutters are so last century!

What you need is flame thrower! One of those portable camping gas tins, a few left over parts off LOHAN and you're sorted. A LOHAN GAGA merging...could call it something like urmm BRITNEY :P

[Pete 2]

Tanks for the idea

If I was designing an autonomous vehicle to go motoring around the garden hacking down plants, grass and anything else that got in its way, I'd be drawn to a RC model tank as the basic platform. Apart from the sheer "cool" of a tracked vehicle, I reckon that when you scale up the natural contours of a less than perfectly flat lawn, then that's a reasonable match for something designed to drive over battlefield terrain.

Depending on the amount of ground clearance, there should be scope to mount a rotating-wizzy thing under the chassis; safe for prying fingers, nosy cats and slow-moving grannies. There's also the long-term possibility of doing something with the gun turret. I'd suggest using it as a means of delivering systemic weedkiller to dandelions in the path of the all-conquering garden-force.

[imanidiot]

One thing I feel I need to input here. Castor wheels of any size are not well know for their rough terrain performance. The size you drew there won't work for certain.

[Martin Budden]

Yep, that castor wheel will get stuck. However....

Instead of a small castor wheel, use a large track-ball similar in design to the balls you used to see under computer mouses before they went all optical. Your ball will need to sit in a circular cage around its equator (the cage will probably want three or four nylon bushes to hold the ball snug). You'll also need a nylon bush above the top of the ball which will allow the weight of the PaddockChompBot to sit on the ball. The bigger the ball, the better it will cope with bumps.

GAGA has balls!

[TeeCee]

Re: Yep, that castor wheel will get stuck. However....

Not sure about that. Too much opportunity for the balls to pick up dirt, bits of chopped grass, dog turds etc and gum up the works.

The reason that mice went optical is that the ball ones used to gum up regularly[1].......and that's on a desktop, not out in a garden.

[1] The first IT hardware fix I ever did was to declag the mouse ball on an early Apple Mac, converting it from an expensive paperweight back into a computer.

[Flocke Kroes]

Tried and tested autonomous grass trimmer

http://www.mattcornock.co.uk/photos/image/155

[Yesnomaybe]

Re: Tried and tested autonomous grass trimmer

http://www.husqvarna.com/uk/products/robotic-mowers/husqvarna-robotic-mowers-for-homeowners/

[Anonymous Coward]

I shall be following this project

I have half an acre of lawn in the tropics (30+ degrees & 90%+ humidity) and a push-along mower. It makes a lawn in Blighty seem like the Sahara. It's almost six hours to mow the bastard.

It really needs a decent ride-on mower but I don't have a spare five grand and the idea of laying in the verandah hammock with a cold beer while the lawn takes care of itself is rather appealing.

[frank ly]

Re: I shall be following this project

Why hasn't anyone considered using goats? HiTech isn't always the best tech.

[Adair]

Re: I shall be following this project

Ahem, have you ever seen what a goat leaves behind---not a lot. In less tech reliant communities than our own goats are part of the land clearance arsenal, and very effective they are too.

Sheep, on the other hand do quite a good job if all you want is the grass kept short. When the quarter acre garden of my late grandfather became too much for him to manage, being an ex-farmer, he simply fenced off the bottom half and let sheep from and adjacent field wander in to graze, just don't bother trying to keep any borders or small shrubs.

I reckon the tank idea is a goer, except that wheels allow the cutter to reach right to the edge which is obviously desirable.

[Inventor of the Marmite Laser]

Re: Why hasn't anyone considered using goats?

I hear goats are pretty good at keeping grass down, too.

[Gideon 1]

Re: Why hasn't anyone considered using goats?

Goats are browsers, not grazers. They'll eat all your plants, bushes, trees, and washing on the line before jumping into the next garden to do the same, leaving the grass to grow. If you want grazers, try sheep or geese.

[Anonymous Coward]

Re: Goats

We have snakes around here that swallow wallabies and small 'roos. I imagine a goat would be much appreciated as a welcome change of diet.

[Anonymous Coward]

Re: Goats

I should have added this snippet of info.

[Anonymous Coward]

Re: Goats

It's not all bad news for goats in Australia if the penultimate line of this article is anything to go by.

[Adair]

Re: I shall be following this project

Traditionally the price of a teenager/child to provide motive and brain(!) power was regarded as extremely good value, and enabled the lord of the manor to supervise (beer in hand and body in hammock, of course), or not.

However, I too shall be following this project; and I don't even have a garden, let alone a lawn.

[Sceptic Tank]

Your grass is ass.

Build in voice recognition. You'll be needing it when your fingers are gone.

<===== Ouch! (Crying - hand now detached from body).

So why must the gardening instrument be able to get so close to the edge of the lawn? Put in horizontal and vertical edge trimmers with nylon cord to do the edges. Look after your blade: ankle bone tends to blunt those blades something nasty. You'll need a spade built in to take care of the edges of the flower beds too.

[Don Jefe]

Tracks

I think Pete 2 has it right that treads would solve a lot of problems. I'm afraid it would cause its own problem though. Without being insanely dangerous it couldn't do edges.

[Inventor of the Marmite Laser]

A solution to slow grass growing in the first place

Water the grass with a diluted alcohol solution (Gin, Vodka, etc.)

Grass comes ends up half cut.

[delboy711]

What we need is GAGA

Since my own Mowbot is also getting a bit long in the tooth and a replacement is ruinously expensive the GAGA project is coming at just the right time for me.

With respect to the positioning problem. Any positioning system that is not accurate to within a few centimetres is simply not going to fly. You do not want your robot to fall into the pond or invade your flower borders because its positioning is a little out. The existing perimeter wire works well, but I notice the latest generation of Mowbots manage without the wire but instead have sensors to detect grass or not grass, and apparently can detect grass length.

[Charles E]

Mulching

Actually mulching the grass clippings is really bad for your lawn. The decomposing grass clippings actually take nitrogen out of your lawn, which is the one nutrient the grass really needs most. Mulch is rich in nitrogen, but only AFTER it has decomposed.

If you want to mow a lawn properly, you have to catch the clippings. I used to mow lawns (with certification by a national lawn care company) and I always used a mower with a catch basket. I assure you that collecting and disposing of the clippings was far more work than actually cutting the lawn.

Now if you want a challenge, there it is. Set up your robot to catch and dispose of the collected clippings. And if you really want to do it right, use a reel mower mechanism.

[Anonymous Coward]

If your grass was Emo it would cut itself.

[PikeyDawg]

Mad Max Version

A tank-treaded grass annihilator with a reel/cylinder mower in front... all exposed like something out of a 1980s horror movie. Obligatory... if you make a mower this bad-ass you have to produce a Terrafirminator-style commercial for it.

There's that, or you could go a little more nancy pants on it and make it a hover mower. With adequate edging around the lawn, a robust inflatable bumper on the mower, and an adequately random control mechanism (say, a blower/pusher that randomly rotates to push in a new direction once it detects a stop) you could just let it bounce around the yard with no real intelligence or remote control required. We could call this one the ADHD version.

Beer, because all men deserve a nice cold one when mowing the yard... even if it's just watching a robot do it on our behalf. After all, someone had to turn it on, right?

[Irony Deficient]

1980s hover movie version

It’s a shame that this couldn’t be adapted for the purpose:

http://is.gd/jRWkPV

[Anonymous Coward]

Re: 1980s hover movie version

Wow... at a loss for words

: /

[Anonymous Coward]

Re: 1980s hover movie version

BTW... in case anyone doesn't know what I mean by hover mower, here's one:

http://www.toro.com/en-gb/homeowner/mowers/hover-mowers/pages/default.aspx

Although I'm still not sure why mowing the lawn requires a hard hat : /

[Radlo]

Stick in the ground

In the short term, you whack a stake in the ground and securely attach a popular petrol mower via a length of rope == the radius of your soon to be new circular lawn. Fire up and let it roll up. Later, a semi automomous triangular lawnbot with 3 auto feeding strimmers on the angles will tackle any edging issues. Orientation and navigation via any popular 9DOF IMU and a few coded IR reference LEDs around the estate for Wii mote positioning and then stand well back. Hours of fun working out the best cutting topology for a quality finish.

Paris as she loves a little triangle.

[Anonymous Coward]

The edge trimming problem

Way back in the days of side-bagger mowers, ours would trim very close on the left side but not close at all on the right.

This comment is here to say that you do not have to mount your blade/motor assembly in the center of the platform. Offset it to one side so you get good close clearance over there.

Correcting for this in software, of course, is left as an exercise at the end of the chapter.

Regards as I head out to trim our 43.5' x 65.3 linguine lawn ... 2.6827 NanoWales in area for those paying close attention.

(it takes longer to set up and stow the equipment than to do the actual job...)

[Geoff Johnson]

Yes, this is a serious question.

Has anyone tried a hot wire cutter to cut grass?

A foot of nichrome wire or something similar at a few hundred degrees C.

[jake]

Re: Yes, this is a serious question.

Yes. It worked, but after three or four weeks it killed the two year old 10x10[1] foot test patch of 89/11 fescue/bluegrass that we use as lawn at chez jake. I have no idea why ... Gut feeling is too much concentrated heat near the top of the roots combined with too much evenly distributed ash.

I didn't fiddle with it much ... Potentially leaving small brush-fires in one's wake here in California is contra-indicated. In fact, after the grass starts going brown we switch from metal blades (mowers) & chains (hogs) to plastic (string trimmers of various sizes) over the bits of the property that we can't use critters on due to lack of fencing.

[1] That's 5760sq Linguine[2]

[2] jake units don't necessarily match ElReg Standard Units ... My linguine are 10" x 1/4" ;-)

[Geoff Johnson]

Re: Yes, this is a serious question.

Thanks, I may have a try myself then.

Over here in England we have more problems with floods than fires, and the extra moisture should protect the roots from excess heat.

By the way, I found a patent for this has been filed.

http://www.google.com/patents/US4952222

[Geoff Johnson]

Thinking out of the box.

So, navigating by on-board sensors is proving tricky, but remote control is going ok.

Why not have the brains of the beast in a stationary location controlling the mower remotely using a stationary camera that can see the whole lawn. If you mod the camera for IR ( See http://www.hoagieshouse.com/IR/ ) and paint the mower black there'll be a really good contrast between the mower and the grass. Of course, the higher the camera the better, as you'll get a more plan view, do you have a roof overlooking the grass?

If you still want the whole thing in one unit, maybe you could use a downward looking wide angle IR camera mounted well above the mower body grass will be bright white to an IR camera so it should see the lawn edges. You'll still need a coarse position from a GPS or something similar though.