Understanding the apparent autonomy of our vacuum cleaner robot

My children are smitten with the family’s new “pet.” Ever since it came into our house, they’ve excitedly asked about it right when they come in the door. We don’t seem to have settled on a name for this new addition, but the kids seem to have decided that we should refer to it as a male, despite having neither genitalia, a pulse or even a face. The “pet” is actually a robot vacuum cleaner, and apparently it appears to have just enough self-awareness and autonomy to warrant being treated like a living thing, even if we all understand that charging batteries isn’t actually the same thing as eating and sleeping. Maybe it says something about how this generation will come to live side-by-side with robots, but explaining how our little suck-bot operates doesn’t seem to make it any less of a companion in my kids’ eyes.

Enabling the air to clean your carpet

These robots are basically self-navigating vacuum cleaners, and the vacuum is fairly straight-forward. Like other vacuum cleaners, they use a motor to blow air out the back of the housing to lower air pressure inside the collection chamber. The little agitator brushes on the bottom help loosen and churn dust up off your floor, at which point ambient air pressure can do the real work. Air pressure at sea level is actually giving a pretty good push in any given direction, but it’s usually balanced by air in the opposite direction, so we don’t really notice it. When the vacuum lowers the air pressure in one place, the surrounding air molecules rush in, carrying dirt and, in our case, small toys with them.

Sensing where to suck

As a human, I usually use my ears and eyes to see if a patch of carpet has been cleaned enough, but these robots don’t have either sensory organ to work with, even if my kids eventually paint some on (which is coming, I’m sure.) Instead of looking or listening to the amount of dirt being kicked up, some models of vacuum robots include a conductive crystal inside. When dirt hits the sensor, it helps complete the circuit and lets the machine know more dirt is getting sucked up. When less debris hits the sensor, less electricity flows and so the robot “knows” it can move along.

Detecting when extra dirt needs attention may give a slight sense of consciousness in these robots, but their movement is obviously the big thing that makes it seem like a living brain is in there, choosing where to go. The fact that the selected directions don’t always make sense to human observers only makes them seem more alive, since the pattern of activity doesn’t look so obvious and planned. Some early robot vacuums from iRobot were actually navigating randomly, hoping to vacuum a room by chance, essentially. Newer robots, including the Neato bot we have, up their navigation with a variety of sensors, including spring-loaded bumpers and lasers that help build an internal “map” of whatever space they’re in.

The infrared lasers are basically an optical version of radar or echolocation. The robot sends lasers out across the room, then monitors how long it takes for that laser to be reflected back. The quicker the return time, the shorter the distance. With that reference point, some robots spiral out from the center of the room until they encounter the perimeter walls, while others crawl along the edges of a space, then work their way across. In both cases, the robot isn’t “seeing” anything, but building up a series of measurements about the size of the space it’s in. An even more focused version of this idea is used underneath the robot chassis, where constant measurements of the distance to the ground are made to make sure the robot doesn’t accidentally drive off a stairway or balcony.

Preprogrammed brains

So my kids haven’t asked to cuddle with the robot, but they have talked about it “watching a movie” with them, which gets to the big difference between a robot and a pet. There’s a good chance that a dog or snake wouldn’t enjoy watching the Minion Movie any more than the robot would, but they would at least have the chance, because their internal programming and logic is a bit more plastic than what a vacuum can handle. As cool as the lasers and navigation algorithms are, they’re limited to that single purpose in a way that many animals’ brains are not. That said, it’s been a few moments since I last stared at my smartphone and drank some coffee, so I’ll have to sign off here before my batteries are depleted…

Source: Roomba® robot vacuum cleaners by Chris Woodford, Explain That Stuff!