ride-on mowing routes/strategies

[Jules]

Silly question time... :-)

I've been mowing our lawns with the ride-on in a kind of spiral pattern, starting from the edge and working my way inwards.

All well and good at first, but our lawns are some rather oddball shapes, and there are various buildings and trees to navigate around - toward the end it seems like I spend a lot of time mowing narrow strips which get left at various points (which require turning the mower around), or on moving between areas that get 'left behind'.

Just wondered if there are any tricks or tips out there to plan a route better and use less fuel, or even do something other than the spiral thing (back-and-forth seems like it'd be worse though, somehow). Googled, but didn't find anything obvious...

No doubt someone's done a PhD on the subject and written some software somewhere for calculating an optimal route ;)

cheers

Jules

[PCPaul]

Well, you could always do it the way the Roomba (little robot vacuum cleaner) does it...

but, then again, probably not.

[John Rumm]

You must be an engineer AICMFP! ;-)

If its any consolation, you are not the first to have had this dilemma!

For straight ish bits I find a combination of either ever decreasing circles (although not decreasing at the narrow ends - so you still get full length (or width) stripes), or the "walking rectangle" work well.

^>>>>>>>>>>>>3>>>>>>>>>>>>>v ^>>>>>>>>>>>>5>>>>>>>>>>>>>v ^

[The Natural Philosopher]

Well Jules, I gut the oddball bits first - like painting where you 'cut in' the corners, and save the long flowing stripey bits till last.

On one square section I go all around teh outside periphery, reversing in one corner at each cut until I have about 3 meters of edge done, then I zigzag across that to finish off, using the edges to turn.

The rest is somewhat trickier: However it passes the extremely tedious time mowing working out and trying new algorithms.

It makes piss all difference to the time, whatever I do though.

But cutting in different directions is good for the overall effect.

[Andrew Mawson]

pattern,

toward the

software

..he..he.. was thinking long and hard about this today as I was cutting the paddock with tractor and topper. I go all the way round in a series of nearish squares until the central bit gets too small to do the 90 degree turn properly, and then do a sort of clover leaf pattern turning in the opposite lock to keep the corners square. Obviously not too efficient, but as the poor old Fordson (circa 1959) effectively can't reverse as the inertia of the topper spinning keeps the gears turning and you are unable to select gear without crashing them. Let the topper spin down and it's ok but that takes over a minute. The alternative is to charge round the outside several times until there is enough headland to turn, then do a series of stripes, but with tractor and topper being about 20 foot long you need a big headland!

AWEM

[Clive George]

Sounds like the sort of problem a CAM package is designed to solve. Not that that helps you much :-)

[Calvin Sambrook]

Ask a farmer, they have exactly this problem when they work fields of crops but it matters much more to them as the tractor trashes a proportion of the crop as its wheels go over it.

You are of course correct, there is very clever software combined with GPS systems used on big fields to get the absolute maximum yield as well as to use minimum chemicals, time etc.

[The Medway Handyman]

Don't have a ride on mower, but I did spend years selling ride on automatic floor scrubber/driers - as used to clean the floors of shopping malls, supermarkets & the like.

do reverse, but leave a puddle of water behind & don't like sharp 'U' turns for the same reason. Back & forth doesn't really work as the 'U' turns leave puddles, but a series of overlapping back & forth passes and a final ride around the edges picks those up.

Mentally dividing the areas into rectangles and using the ever decreasing circles method works pretty well, only leaving one puddle in the centre.

HTH

[Dave Liquorice]

Wouldn't Mr Rumms walking rectangle work? If you make the first return half way down then you'll mow against that just before making the last return at the bottom edge.

[adrian]

[Calvin Sambrook]

I don't really know how important it is for grass cutting but continual ploughing of small strips of land in the same circular pattern back in the days of strip farming was deliberately used to create higher areas interleaved with drainage dips. Each year the strip would be ploughed in a circle with a single bladed plough so gradually the soil was moved inwards. This is the origin of most of the "ripples" you see in fields around the country today, they are a little echo of our heritage.

[Steve Firth]

I have to mow an olive grove, several acres with a regular pattern of trees. The field itself is an odd shape - it's actually shaped like the map of Italy only with a bent knee.

I use a 1.85m wide flail for the mowing, it still takes a good 14 hours work to mow. My tractor can't do tight turns without ripping up the turf so I'm limited in what I can do, so I mow in a spiral as you suggest. This leaves "islands of unmowed grass pointing up and downhill from each tree so I then do a final zig-zag mow side to side to mow down each island.

[Jules]

Heh, yes I do that too, and always play around with slightly different strategies (all of them somehow spiral-based, although I've tried splitting the lawns up into different sections to see if it helps).

Whatever I do always seems to end up with a certain amount of doubling-back, or strips that can no longer be done in a spiral due to the limited turn radius of the mower. I was wondering if I was missing some trick that the porfessionals use (or even if the spiral approach was flawed), but it sounds like everyone has the same problem.

It's not *that* big a deal; since I did some engine work and deck work I can cut in under 2 hours now - it just bugs me to think I might be wasting fuel that I don't need to :-)

because straight lines between points aren't always possible (objects in the way), and the limited turn radius of the mower negates certain 'moves'.

I'm in a geeky mood, so off the top of my head a computational solution might be to abstract the grass as a series of grid squares (the diagonal of each square being the width of the mower deck), specify rules as to allowed movement between squares (doubling back is made somehow 'expensive', but possible), and just let a computer crunch away testing different routes and calculating optimal ones.

As for actually programming the darn thing so that it rejects anything that's obviously silly, and doesn't try to run the exact same route more than once, though... the number of possibles must be quite astronomical.

Another issue is that some obstacles - e.g. trees - end up being smaller than a single grid square. Maybe I'll throw down some bark chips or just attack those with the lawn edger ;-)

cheers

Jules

[PCPaul]

Feed your geeky side...

This link leads to a complete free book on path planning algorithms.

Let us know how you get on ;-)

[Tim Lamb]

In message , Calvin Sambrook writes

This was all worked out years ago to minimise the effort involved in cultivating land with horses. Because single furrow ploughs only turn the soil one way, you can't simply go back down the row you have just done without walking further and further at each end as the worked piece gets wider. Holding the plough out of the ground while the horse plods along the headland is hard work and wastes time. Working lands is the most efficient solution.

Applied to mowing lawns this means cutting the outside first (headland) to create space to turn. The remainder is then bi-sected parallel to the straightest/longest edge; choosing an amount to give a reasonable headland run. Initially the return cut will be along the headland until the new cut is wide enough for the mower to turn comfortably and work inside the new piece. Eventually the headland turn on the new piece will be longer than that for the residue which should then be finished off. And so on:-)

regards

[Jules]

Is it? I thought it was usually the way things like 'serious' chess programs and other game-related progs work; by testing options - along with rules to reject anything that's obviously barmy.

cheers

Jules

[Roger]

The message from Jules contains these words:

I have come late to this thread as I have only just returned from a long weekend away.

I probably agree with much of what has already been said but I have noticed that as my mower changes so does what I think is the optimum course for awkward areas, and my grass is just about all awkward areas.

It seems to me that if it is time you want to save and you have a mower that will not cut in reverse (as I have at present) the last thing you want to do is stop and then reverse if you can at all avoid it so my cutting is aimed at keeping moving even if it means going over some areas several times.

I also try to build some variation into the pattern so I so I don't continually cut on the same lines but there are some places where I have no choice but to mow the same way time and time again.

And finally my current mower has an offset deck so I really have to mow edges in one direction only or get the strimmer out as well.

FWIW I think that you will do less distance if you cut a main area first and then mop up the missed patches before moving on to the next area but whether that is significant or even at all beneficial depends to a large extent on the nature of your awkward shapes.

[Jules]

Not sure what newer mowers are like, having never had one, but ours is a pig to switch between forward and reverse anyway (I'm not sure if it's just crappy gearing design or wear, but I have to really back off the throttle and 'tickle' it into gear, often whilst slipping the clutch), so I prefer not to back up if I can avoid it.

Ours is central, thankfully, but it makes sense to cut one way anyway I think, just so I'm not blowing cut grass all over the bits I haven't yet mowed (a grass collector would be nice, but I don't stand much chance of finding one for our ancient mower, and I don't know enough about how they work to try and DIY one)

Yes, that might be. We don't really have a 'main area' as such though - there's a barn, fire pit, workshop, wood pile, house, sheds, septic tank caps, propane tank, clothes lines, power pole, telegraph pole, and various trees all conspiring against me. That's before factoring in that the perimeter of the grassed area looks like one of those Rorschach ink blots ;-)

(sounds hellish, but I don't mind - I enjoy mowing, I just always end up wondering if I'm going about it in the best way)

cheers!

Jules