Creating lawn mower grid missions with reversing back and forth

Hi,
I’m looking for a convenient solution for creating missions for my lawn mower. It’s a skid-steer, track based and quite heavy vehicle and the issue is that where it performs pivot turns or tight curves you won’t have to mow the lawn for a while anyway. Because it will somehow plow that area with its tracks like a small tank :smiley:

So when controlling it manually, usually my pattern is to go back and forth (reversing at each end) and “changing lanes” with as little steering as possible, like so:

This is a mission I created manually in large parts using Excel and I’m looking for a way to automate this more. Ideally having to draw a polygon and with the possibility to add inner exclusion zones (mostly for trees, i.e. round).

I guess there is no ready solution for that, but maybe something to start with…? Thanks for any ideas!

There is a survey grid feature where you can draw a polygon and create back and forth paths (and even specify the heading if you prefer).

They are ~90 degree corners in most places, though, and you cannot specify exclusion zones, though you can enable obstacle avoidance and put fences around fixed objects.

Yes thanks, I’ve been there, but that’s what results in quite f… let’s say messed up edges due to the ~90° turns, especially on humid soil (it’s hilly with lots of clay here).
So I literally need to reverse using DO_SET_REVERSE each time it hits the polygon or an obstacle, so to avoid as much steering or pivots as possible.

If there is nothing on this yet, I’ll try my hand at it these days…

There’s a spiral path option that most of us use for exactly the reason you state. I don’t like robot mowing with the standard back and forth path.

This is a video I made during development. Reversed perimeters now a native feature.

1 Like

Great content you created there, I have seen that already some time ago with interest. And I totally agree with the spiral path for your mower and surface type.
But spiral isn’t a good choice in my case because:

  • Perimeter around the house/garage already has many angles
  • Many obstacles like trees
  • Terrain is hilly - you don’t want the rover to go sideways
  • …and the tracks do really dig stuff up as soon as you start to turn >30°

This type of mower requires another pattern, at least for my use case.
grafik

Following this. We are using a similar mower design. Turning 90 or 180 takes a while and makes a mess. Backwards and fowards is way more time efficient.
I like your excel approach, i’ll do the same once we get a couple of other kinks out.
At least figure a generic way to build some back n forwards path, and coding skills aside - doing a Yuri and merge it into MP.

Yes, exactly. I’ve got some ideas in my head already for an algorithm to create such a pattern. I’ll try to put that into code when I find some time (will be C# probably, that’s my daily business anyway), and if it works then we could create a suggestion to adapt and merge it into MP.

I know it’s been a while since you posted this, but when I was deciding on the mower I wanted, tracked vs wheeled, which one would tear up my lawn the least was at the top of my list of deciding factors.

I’m just in the planning stage, but one of the things I plan on testing/tweaking is turning radius. I do have experience with tracked combat vehicles, and if you can avoid fully braking either track, it 1. does less damage to the turf, and 2. decreases the likelihood of a thrown track.

I know that turning tightly is ideal for planning a mowing mission, since your cutting paths are right next to each other, but you might be better off making the turning radius a little less than the width of your vehicle. This would force you to run two missions since you would be skipping a row of grass each time, but with RTK you should have no problem hitting the grass you missed on the second run.