Fiducials on docking station

Very often my robot has problems docking, as I mostly have carpets.

I do see very weird behaviour, where "he" gets very close many times, and then goes off on a mission elsewhere in the room and ends up nowhere near the dock with a flat battery.

This raises the question, if he has seen the dock with 100% certainty, why did he do that. I wondering if he "he" wasn't 100% certain it wasn't the dock, and perhaps having something totally unique like stick on fiducials a fixed distance apart may help. It would also help its final push onto the dock if it had the fiducials aligned before it did it's forward move.

Does the robot know what the docks looks like, or does it work from a map?

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  • magnus_lindhemagnus_lindhe Member ✭✭

    Hi VimFuago, there are a type of fiducials behind the black screen in the charger. It is actually transparent to IR, and behind it there are two horizontal reflective strips at a known distance from each other. So usually the robot gets a very unique intensity signature when it sees the charger.

    It has a map of the charger location, and uses that to get back home. Then it observes the charger while docking, to adjust its position and cancel out any navigation error that it has accumulated while cleaning.

    But the robot only "sees" things along the two laser lines that extend forward right and forward left from the front of it. So sometimes when cleaning or searching for the charger, the robot turns too quickly or sees the charger at an angle, so the laser lines pass over the charger too quickly to get enough detections. Maybe that is what happened in this case?

  • VimFuagoVimFuago Member

    Thanks, it's interesting to know that these things are already being done by the robot as part of its detection and docking sequence

  • KatharinaKatharina Member

    Oh, this was really interesting!

    I have been wondering how the bot navigates the final bit on its way to the charger, as sometimes it seems to have a really hard time with it even though it's really close.

    Keep those technical details coming. Love that stuff :smiley:

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