Waiting for Probotics to get in gears and watching my lawn grow, I had
The flat, knobby wheels actually get very poor traction in turns.
That's true whenever you've got a contact patch width which is
significant in relation to the spacing between them, and the Robomower
design is most definitely that.
This ends up with 2 problems. One, the inside and outside edges are
trying to run at two different speeds in a turn, which means one or both
edges are in a skid rather than sync'ed with the surface beneath them.
Skidding greatly reduces traction, efficiency, and wheel life.
Two, it tends to cause course confusion as the center of this sort of
skidding turn is very unpredictable. The mower's magnetic guidance will
be able to put it on the correct compass heading but it can be displaced
from where it thinks itself to be in an XY sense. Not of any real
consequence in the basic mowing pattern which tends to go all over the
place, but it's probably a REAL problem in the algorithm to get around
an obstacle. Most of us are quite familiar with the "stuck on stupid"
effect where it hits something, tries to back out and turn, then rams
itself right back into the same spot over and over. This might be a
factor in that.
There are plenty of high quality, high traction robot wheels out there.
They'd need to be a very good match for diameter and I'd have to figure
out how to make the drive work... but, it's "interesting".