(Updated January 30, 2012: Added the Dirt Devil.) I finally got the time, equipment, and software together to make long exposure photos of the different floor cleaning robots to look at the differences between the three. So, above is a long exposure of an iRobot Roomba cleaning up the “hall” in my house. It’s about eight feet long and maybe 5 feet wide. There is a furnace return in the upper left corner that the Roomba avoids, thinking it’s a cliff.

Here you can see the orderly progression of how a Neato Robotics XV-11 cleans an area this small. It does the perimeter, and then precisely vacuums the area inside. You can’t tell from the photo, but the line in the middle is actually from two paths. One going from left to right, and the other from right to left.

This is my favorite of the bunch. The Evolution Mint Cleaner goes back and forth, and then does the perimeter, but much more meticulously than the Neato robot. So it leaves quite a bumpy trail around the room.

The Dirt Devil RoomMate runs around a room pretty much like a Roomba does, with alternating behaviors. It does random bouncing around, spirals, and wall following. In a small area like this, it spends a lot more time doing wall following than anything else. Like all the rest of the robots, it’s not a big fan of the furnace return.

Here’s a photo with the lights on, following a Neato XV-11 through the room again. It took a different way to do it this time, going up and down instead of back and forth.

Did I mention that I made these photos with an Olloclip fisheye lens? I don’t usually talk about things other than robots on this blog, but this thing is really cool. It’s a three-in-one add-on lens for the iPhone 4. It has a fish-eye lens, a wide angle lens, and a crazy macro lens. Here are some other photos I’ve taken recently.