Today it happened again, the robot found dead on a small treshold next to the charging station. This happens often, but just for a month or so, earlier this did not happen.
If you put the robot in that spot and turn it manually, does it feel like it hooks into the threshold?
Not at all. It just don't know how to get over it... it just drives to treshold slowly, and then trieds to rotate around on it.
Earlier the behaviour was as I thin it should be: Stop before the treshold, then accelerate directly over it. Now it seems that the treshold comes as surprice for the robot.
Ah, I see. Actually, it could be related to the robot being lost or for some other reason having trouble getting to some position. It does some investigation of the neighbouring area - during this movement, it does not correctly look for thresholds. A known bug, sadly.
Looking at the logs, this happened during the robot's return to the charger. It might help if you move the charger to a different spot, further from a threshold.
Today's action: https://youtu.be/QZx9ea3Cuck
First it faced "surprice treshold" but after some rotation decided to do the right thing.
Todays attempt: https://youtu.be/6gfdeQOwq7c
Now it got jammed to the same very low treshold.
It's probably the case that the robot has a hard time seeing the threshold. To test this theory, you could try putting some matte tape on the angled part. Of course not a permanent solution, but could help in correctly identifying what is happening.
Looks that the latest firmware update made a big difference. Now it doesn't run to this treshold anymore like it used to do. No changes in the envinronment, except moving the dock little farther from the treshold, which did not help.
Here is video about one of latest successful runs: