If you’re anything like me, you’re fascinated by the idea of robot vacuum cleaners.

These mini-machines manage to cruise around your house and somehow keep it spotlessly clean.

But how do robot vacuums work exactly?

How do they know where to go, where they’ve already cleaned, and how to avoid knocking over your furniture?

As your trusty companion, I’ll teach you everything you need to know about how robot vacuums work to clean your home. By the end of this post, you’ll know all about how these futuristic machines “see” and “remember” every nook and cranny of your house.

And when you’re done reading this page, check out my best inexpensive robot vacuum list. It shows you how to find the cheapest robot vacuum for your money that rivals the more expensive brands, like Roomba and iRobot.

How Do Robot Vacuums Work to Clean Your Home?

Although robot vacuums seem like highly intelligent machines, the truth is that they’re not that complicated of a device.

There are really just two ways that a robot vacuum cleaner finds its way around your home:

  • Sensors
  • Mapping

In basic terms, sensors help the vacuum not bump into things or fall down the stairs while mapping keeps a log of the floor space where the machine has already cleaned.

I’ll go more in depth about each of these technologies next.

Sensors help the robot vacuum “see”

If you look down at a robot vacuum, you may wonder how it knows how to get around your home.

Obviously, it doesn’t have eyes or the ability to perceive 3D space, yet somehow it still manages to navigate freely throughout a room without injuring the furniture or itself.

The secret behind a robot vacuums effortless maneuverability is onboard sensors.

Sensors are what help the robot vacuum see around your home and avoid obstacles in its path.

These sensors are what detect hazards, helps the vacuum avoid obstacles, find new areas to clean, and measure the distance from the charging base so it can return at the appropriate time.

While every manufacturer and model includes its own unique set of sensors, you’ll find that the ones listed below are the most common.

  • Obstacle sensors: These are shock-absorbing sensors that detect physical objects in a room, such as table legs, couches, and other furniture. When a part of the robot vacuum bumps into one of those things, the sensor helps it determine if it can go around the object (like a chair leg) or if it must divert itself in another direction (like running into a piano base). Some obstacle sensors are also touch-sensitive, meaning that they can tell the difference between hard and soft objects. This sends a signal to the robot vacuum, telling it if it should try to push through the object or not, like a soft bed skirt or curtain versus a hard planter.
  • Cliff sensors: These sensors are what prevent the robot vacuum from falling down the stairs. They work by measuring the distance from the device to the floor through an infrared signal. If the signal doesn’t bounce back, then the robot vacuum knows that a ledge (or cliff) is up ahead and then changes its direction.
  • Wall sensors: These sensors help the robot vacuum clean alongside a wall for long distances without bumping into them or scuffing the paint. Like cliff sensors, wall sensors also use infrared beams to detect where the floor meets a wall surface. Wall sensors also help the robot vacuum move around doorways.
  • Wheel sensors: These sensors record data for how far the robot vacuum has traveled from the charging base station. It does this by measuring the number of times the wheels rotate.

While all of these sensors help the robot vacuum navigate better around your home, the one thing they can’t do is remember where the machine has cleaned.

The sole purpose of sensors is to keep the robot vacuum from running into objects or falling off a ledge and getting damaged.

To create a “memory” of where the robot vacuum has been, it must include a mapping feature, which I’ll describe next.

In cheaper robot vacuums, all you’ll find are sensors and this is what makes those models less efficient than the higher-end Roombas and iRobot vacuums.

Although a cheap robot vacuum tends to clean in haphazard paths and makes multiple passes throughout a room, over time, these machines do clean up the dirt off your floors. You just have to be a bit more patient with them.

Mapping helps the robot vacuum “remember” where it has been

In higher-end robot vacuums, you’ll find a feature called “mapping” which is basically a self-navigation system that helps the machine do a better job at cleaning your floors.

Mapping creates a memory for the robot vacuum. That way, it knows where it has already cleaned inside your home and won’t waste time go over the same spot twice.

In robot vacuums that include mapping functionality, you’ll find that they work their way through a room in a logical path. Usually, it’s a back and forth motion that winds its way across the floor, similar to how people mow their yards with a push mower.

With the floor space mapped, a robot vacuum can easily return the base station to recharge and then find its way back to the location where to stopped to start cleaning again.

While each manufacturer uses its own type of mapping, the concept is designed around two basic versions:

  • Digital camera: This type takes pictures of the walls, furniture, doorways, and other objects as a way to build up memory of where the device has already been.
  • Laser: This type uses a laser beam to track the floor space and objects in the room to create the map during cleaning.

In either case, the robot vacuum is able to record the physical layout of a room so it can plot a more efficient route.

One thing to keep in mind, however, is that mapping navigation isn’t perfect.

If you ever pick up the robot vacuum during it’s cleaning process and not set it down exactly in the same spot, then the mapping will get out of sync.

Also, low-light environments can make it hard for the mapping technologies to do their job well. Dark rooms interfere with the camera and laser beam functions.

That’s How Robot Vacuums Work

I hope you enjoyed this overview of how does a robot vacuum work to clean your home.

As you discovered, these are not very complicated machines and they’re essentially controlled by various sensors, cameras, and laser beams.

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Your pal,
Trusty Joe