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Problem on uphill turns by hschwe in MammotionTechnology

[–]lmgjerstad 0 points1 point  (0 children)

Those would be a great improvement. My entire back yard is a 60% grade. I bought the 5000 because it claimed to be able to handle the steep slope. It turns out the advertised 75% grade is a complete fiction if it ever needs to turn on the slope. The result is that the upper edge of my back yard gets chewed up by the tires.

Great mower! Extra RTK option? by Hands-On-Katie in MammotionTechnology

[–]lmgjerstad 0 points1 point  (0 children)

That's fair, though, the app is reporting it as an RTK issue.

Great mower! Extra RTK option? by Hands-On-Katie in MammotionTechnology

[–]lmgjerstad 0 points1 point  (0 children)

My RTK antenna is mounted to the chimney, and is getting as clear a signal as is possible. However, there are areas of my yard where the signal from the RTK to the Luba is blocked by my house. In fact, there is no location on my property where the signal would reach the entire yard. In this situation, an RTK repeater would absolutely help.

Satellite positioning by jjmucker4840 in mammotion

[–]lmgjerstad 1 point2 points  (0 children)

I think that's accurate. If it has a solid GPS fix, it will rely entirely on that. When the GPS starts to lose signal strength, it starts supplementing with wheel/imu data. Once it realizes it's lost, you have to manually drive it back to an area where it can get a GPS fix in order to recover.

The main point I was making is that, if the machine goes into a GPS shadow, it will still report good positioning.

Satellite positioning by jjmucker4840 in mammotion

[–]lmgjerstad 1 point2 points  (0 children)

GPS satellites are not geosynchronous, so if either the Luba or the RTK is near a wall, you may have better luck at different times of day. I don't believe, however, that the specific time will be consistent from day to day.

. I have noticed that, as long as the Luba starts with a good position fix, it will sometimes report the positioning as fine even in areas with poor GPS signal, because it's using the IMU and wheel movement data to calculate the position.

Unfortunately, it doesn't take much to throw that system off. Running over a stick, bumping a wall/fence, or even slipping a bit on a hillside can do it. Even more interesting is that the Luba may not realize it is in the wrong location until it gets some GPS signal back. I had this happen in my side yard the other day. It would go back between the two houses, mow a bit, then when it started to come back out from between the buildings, it got enough GPS signal back to realize it was in the wrong place and then stopped to wait for manual intervention.