Experiments · Robot vacuum · home hallway
A robot vacuum in our hallway, scored from one phone video
No tags, no tripod, no special setup. Just a robot vacuum doing its thing and a phone held at the end of the hallway. Here’s what MotionBench made of it.
- Floor covered
- 85%
- Swept more than once
- 51%
- Distance driven
- 18.6 m
- Average speed
- 0.14 m/s
Over 137 seconds and 3.24 m² of visible floor, with a 30 cm cleaning width (89% if you count the robot's whole 35 cm body). It drove neat back-and-forth lanes; most of what it “missed” is a thin strip along the walls, where its side brush does the work and our simple model doesn't give it credit.
How a phone video becomes a score
1 Steady the shot
We held the phone at the end of the hallway for two and a half minutes. Hands wobble, so every frame is lined up with the first one using the texture of the floor.
2 Make the robot disappear
Stack all the frames and keep the middle value of every pixel. The robot never stays in one place, so it vanishes and leaves an empty floor. Anything darker than that empty floor is the robot.
3 Measure the floor without tags
Floorboards are straight and parallel, so in the picture they all point at one spot. That gives the direction and tilt of the floor. The robot is the ruler: it is about 35 cm across, so we fit the camera until a 35 cm robot matches what we see in hundreds of frames.
4 Track it and score it
Each frame now gives the robot's spot on the floor in metres. The same open-source scorer as every other MotionBench run counts the floor it swept with a 30 cm cleaning width.
Replay it yourself
The same explorer we use for every run: scrub through it, and watch the page re-count the covered floor from the raw positions and check it against the scorer.
What this run can and can’t tell you
- It's one clip in one home, so it isn't a review of any robot vacuum. It's a test of the method.
- Nobody has vacuumed this hallway on camera yet, so there's no human score. That's our next run: the same hallway, filmed from the same spot, with one of us pushing a vacuum.
- Without tags, the size is an estimate. Our hallway comes out 1.06 m wide; a tape measure will tell us how close we got. Printed tags make this exact.
- Floor right in front of the camera was out of view, so it's left out of the score (hatched in the replay). One check flags a two-second gap where the robot slipped out of frame, and the safety count mostly reflects the robot hugging walls on purpose.
Want exact numbers for your own run? Print four tags for the floor and one for the robot (capture guide).