Repeatability (Re-localization Accuracy)

Repeatability is how far the robot's actual parking positions disperse when it returns to the same target point many times — not how far it is off the map origin, but whether it can stop at the same spot every time. Commercial docking usually requires 10mm-class.

What problem it solves

Every day the robot must auto-dock to charge, connect to a fixed station to pick up material, and stop at a shelf. If the parking position drifts 5cm each time, the charging contact won't mate, the station interface won't plug in, and the arm misses the part — whether it can "return precisely to the same spot" decides whether docking tasks can be automated.

Patrol, security and cleaning paths are forgiving — a few cm off doesn't matter. But docking chargers, loading stations and shelf pick points are "millimeter-sensitive"; there the number that matters is repeatability, not overall mapping accuracy.

How to read the key specs

Repeatability ±X mm: dispersion radius across repeated returns. Commercial docking generally needs ≤10mm; look for the word 'repeatability / docking accuracy' on the spec sheet.
Lateral vs heading: separate longitudinal (along the robot) and lateral (across) errors; for station docking the lateral offset is usually the most sensitive.
Docking aids: a light target, visual marker or mechanical guide slot absorbs the last few mm; hard-stopping on localization alone demands more from the algorithm.
Localization accuracy ≠ repeatability: localization accuracy is “how far off in the map” (absolute); repeatability is “how consistent each return is” (relative spread). Even a skewed map can give great repeatability.

Common misconceptions

Myth 1: Good mapping = good docking. Mapping accuracy is about absolute coordinates; docking is about repeat dispersion. If the map has a 5cm fixed bias but always the same direction, repeat docking stays accurate.

Myth 2: Smaller repeatability number is always better. 5mm may require reflectors/QR codes/mechanical guidance and cost a lot; most chargers and stations are fine at 10mm. Choose by docking tolerance.

Myth 3: The rated spec is the on-site result. Floor flatness, speed, payload and turn angle all affect real parking; test on your own floor — don't trust the datasheet alone.

Recommended models

All Tbot platforms offer ±10mm repeatability with auto-charging and station docking: Tbot-N5-3D, Tbot-OMNI, Tbot-Clean-U75. Full specs: Spec Sheet.

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Repeatability (Re-localization Accuracy)

What problem it solves

How to read the key specs

Common misconceptions

Recommended models

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