Building a mower. One challenge is to trim around a bush. I have many with a 36"D rubber bed. I need the mower to mow around this bed in a 36" diameter circle, with some precision. So the function would be to run a circle centered around a specific waypoint, with a defined radius (less than 1 meter). It would, at first glance, seem that either circle or loiter mode might be appropriate, but neither seems to work. So I’m looking at spline waypoints as a possibility, probably 6 of them, spaced equally around the bush. Has anyone else gone down this rabbit hole and been happy with results? I have one stretch of isolated bushes that need mowing around the entire bush. Or is there some other function that I’m not aware of that does this job better?
Pretty sure splines are not implemented in rover yet. I think circle waypoints are the intended way to handle your requirement. (For what it’s worth we weren’t able to get them to work… sometimes the mower would not navigate the full 360 before deciding to move on to the next waypoint … we actually mowed down a sapling in one failed test… could very well be operator error though). We ended up using octagons.
Indeed, no splines. BendyRuler and circular exclusion fence avoidance can approximate the desired behavior, but only so well, and the tune needs to be REALLY good to minimize the oblong unmowed section on the downstream side.
Manual waypoint manipulation is likely the best solution at hand if you want to avoid custom software integration (like Chris has implemented in what I’m pretty sure is a closed source/proprietary commercial project).
Thanks for the input. Two other questions. Circle, which goes to a point X in front of the mower and circles it would not work, right? You would have to be very precise in leading the mower to that point to make sure it was oriented right, pause it and hope it gets it right?!? Sounds pretty sketchy. And doing it in the middle of an automated mission seems like another problem. My bushes are highly prized and I’d be devastated if one was run over. Second, is there any call for such a function: circle X waypoint at Y radius, Z number of times, then move to the next waypoint? Sounds like a minor tweek to the normal circle or loiter function? If others might make use of this, can someone with more pull put in a request? Or should those brownie points be used for something more important? In the absence of a better approach, I think the octagon will have to do. Or 6-8 manual waypoints per bush…Or perhaps a request for spline waypoints in rover would be easier to implement? Yuri, I saw your YT some time ago using bendyruler and fence to go around trees and if memory serves, it was a pretty poor approximation of trimming around a tree, and I’m sure your tuning is far better than mine. Last thought: could a script be inserted into a mission to do that? Or are scripts just stand-alone programs? Right now, I think manual waypoints are the approach, combined with a wire-guided mower I already have, to get close, with safety.
Circle mode sounds like a terrible idea.
BendyRuler is likely safe but may result in a wide margin.
Scripting could work, and I have tried it with some success, but it’s pretty painful for trying to navigate obstacles with safe repeatability. I got great results, but I abandoned it because it was very hard to maintain and debug.
At the level you are operating, manually inserting waypoints is likely the safest and most effective option.
Thanks, Yuri. Manual it is. Glad to get my random “is that possible” thoughts gone.