Skip to main content
Robot Vacuums

Curious about that Roomba? Here’s how a robot vacuum works

Technically speaking

The iRobot Roomba i3+ on a table Credit: Reviewed / Jonathan Chan

Recommendations are independently chosen by Reviewed’s editors. Purchases you make through our links may earn us a commission.

Robot vacuums are as useful as they are mysterious. Part of the mystique comes from the fact that robot vacuum manufacturers use acronyms and techno-jargon to describe the features of their products.

In this article, we answer the question of “How do robot vacuums work?” so you can get a sense of things and understand some of the buzzwords used about these automated floor cleaners.

Most importantly, this is how a robot vacuum cleans

The brush roll of the Eufy G30
Credit: Reviewed / Jonathan Chan

Robot vacuum brush rolls often use rubbery bristles to deal with dust.

There are a lot of variations in robot vacuum design, but most of them follow a similar pattern. A good example is the iRobot Roomba i3+. It has a side or edge-sweeping brush and a center brush roll that is usually made of a rubber-like material that helps clean away dust that has adhered to the floor.

Aside from brushes that sweep up dirt and debris, robot vacuums also have motors that create suction. Air gets pulled into the dustbin and then passed through a filter. Most robot vacuums have a single filter, but models like the iRobot j7+ or Shark RV1001AE have filters inside the robot vacuum as well as an additional one located in the self-emptying base.

Without navigation, robot vacuums wouldn’t be able to clean well or autonomously

The camera of the Trio Lucy Pet
Credit: Reviewed / Jonathan Chan

Some robot vacuums use cameras to recognize objects in front of them.

The majority of robot vacuums on the market today use one or more of the following technologies:

  • Lidar: This technology uses pulses of light to judge distance. Through multiple pulses, a robot vacuum can figure out the shape of a room and any obstacles in it. Lidar is a cost-effective and reliable technology.

  • vSLAM: Visual simultaneous localization and mapping—or vSLAM—is a camera-based method of robot navigation. By analyzing a succession of video frames, a robot can determine the distance of objects and its location relative to them. Robot vacuums using vSLAM can “see” more of the room per sweep than models using Lidar.

  • Object Recognition: This is an emerging technology in the robot vacuum world. With machine learning, robot vacuums can actually figure out what their camera is looking at and act accordingly. For example, a robot vacuum with object recognition would know to avoid power cables but also know to drive through a bed skirt.

Without one of these “seeing” technologies, your robot vacuum would be more likely to wander around aimlessly cleaning the same spot over and over again. This was a major complaint consumers had with the first generation of robot vacuums.

Related content


The product experts at Reviewed have all your shopping needs covered. Follow Reviewed on Facebook, Twitter, Instagram, TikTok, or Flipboard for the latest deals, product reviews, and more.

Prices are accurate at the time of publication but may change over time.