So my cousin has a robot mower and Ive watched it get stuck in the same 3 spots for 2 years. the strip between his AC unit and the fence (about 16 inches). the corner where his patio meets the lawn at a weird angle. and a dip near the driveway.
I figured it was a software thing. mapping just not learning those spots.
Then I sat down with a tape measure and the geometry explained 2 of 3.
Most robot mowers have a wheelbase between 14-16 inches. so the 16 inch AC strip is basically impossible to turn around in. it backs out or scrapes through. scraping triggers a tilt sensor and it gives up.
The patio corner is different. RWD mowers (most Husqvarnas) pivot from the back so the front swings out and clips the edge. AWD (LUBA 2, NERA 435X) handles this fine but costs like double. then theres FWD with a rear caster which I'd never heard of til last week. Goalker H3 Pro on KS uses it, caster rotates freely so turning radius is near zero. Mammotion did similar on the Mini 2 AWD.
the dip I still cant explain. probably weight distribution.
made a diagram cause writing it out was confusing. anyone running FWD+caster in real life? as nimble as the math says or is there a downside?
EDIT: yeah AWD is the safe bet. just trying to figure if FWD+caster is real or marketing.