# How does a robot vacuum work? Navigation, suction, mopping and the station

> A robot vacuum uses sensors to measure where walls and furniture are, builds a map from that and drives a planned route. Brushes sweep dirt inward, suction pulls it into the bin, and some models mop as well. A station can empty the bin.

Edited by Martin Kilarski. Published on November 7, 2026, updated on November 7, 2026. Founder and editor of Best at Best, with ten years in web development and a focus on search, conversion and data analysis.

## How does a robot vacuum find its way?

ECOVACS writes that a robot uses [sensors such as cameras or LiDAR](https://www.ecovacs.com/au/blog/how-does-a-robot-vacuum-cleaner-work) to map your home. With that map it plans an efficient route, instead of bumping into things at random and missing spots. There are three common kinds of navigation:

- Gyroscope or IMU: tracks which way and how far the robot drives and builds a simple map from that. ECOVACS says this is often seen on basic models and is less precise than lasers or cameras.
- LiDAR: a laser measures distances all around the robot.
- Camera (vSLAM, according to Dreame): the robot recognizes fixed landmarks such as door frames and furniture and works out where it is.

Dreame explains that [LiDAR](https://www.dreametech.com/blogs/blog/lidar-navigation-robot-vacuum) sends out laser pulses and measures how long they take to bounce back. From that the robot calculates distances and builds a floor plan. After one run it saves that map and reuses it on every later clean.

## LiDAR or camera: what is the difference?

Dreame sets the two side by side in [a comparison](https://www.dreametech.com/blogs/blog/lidar-vs-vslam-navigation). The laser maps precisely, even in the dark, because it carries its own light. It scans at a single height, so it can miss small or low objects, and it cannot tell what an object is. Transparent and black surfaces are hard for a laser to read.

A camera recognizes what is on the floor and adjusts the cleaning to it. According to Dreame it needs some light and maps more slowly and less precisely than a laser. Many newer models therefore combine both: the laser for the floor plan, the camera for obstacles. That is often called obstacle recognition.

Robots also carry sensors on the underside. ECOVACS names cliff sensors that look down and make the robot stop and turn away at stairs and ledges.

## How does it pick up dirt?

ECOVACS describes it as three parts that work together. Side brushes sweep dirt toward the middle, from corners and along edges. The main brush loosens dirt and lifts hair out of carpet and cracks. Suction then pulls everything into the bin.

On some models the suction adapts. ECOVACS says advanced robots can [raise suction on carpet](https://www.ecovacs.com/au/blog/how-does-a-robot-vacuum-cleaner-work) and lower it on hard floors. How far a model gets on a charge is on its own page.

## How does a robot vacuum mop?

Not every model mops. ECOVACS writes that a model with a mop function picks up [fine dust and dried stains](https://www.ecovacs.com/au/blog/how-does-a-robot-vacuum-cleaner-work) that vacuuming alone leaves behind. Dreame lists a water tank and mop pads among the parts of such a robot. Some models lift the mop pads or adjust the water flow when they sense carpet.

On a model with a station, the station washes the mops. Dreame lists [rotating brushes that scrub the pads, plus hot-air drying](https://www.dreametech.com/blogs/blog/are-self-emptying-robot-vacuums-worth-it) as part of such a station. A station differs per model, so check what the maker states for the model itself.

## What does the station do?

The robot has a small dustbin. A station with an empty function sucks it out. Dreame writes that the robot parks [over the station’s intake port](https://www.dreametech.com/blogs/blog/are-self-emptying-robot-vacuums-worth-it) and the dirt moves into a larger bin or bag in the station. That means you empty far less often yourself. How long that lasts depends on your home and the size of the bin.

Here are the three kinds of station and what they cost now:

| Station | On sale | Median price | Cheapest | Cheapest in the ranking |
|---|---|---|---|---|
| charging dock only | 2 | $154 | Roborock Q7 L5, $139 at Roborock (brand store) | [Roborock Q7 L5](https://bestatbest.com/us/robot-vacuums/roborock-q7-l5), $139 at Roborock (brand store) |
| self-emptying station | 12 | $329 | Roborock Q7 M5+, $249 at Roborock (brand store) | [Roborock Q7 M5+](https://bestatbest.com/us/robot-vacuums/roborock-q7-m5-plus), $249 at Roborock (brand store) |
| all-in-one station | 78 | $799 | Ecovacs Deebot N30 Pro Omni, $315 at Ecovacs (brand store) | [iRobot Roomba Plus 415 Combo](https://bestatbest.com/us/robot-vacuums/irobot-roomba-plus-415-combo), $379 at iRobot (brand store) |

On sale today by kind: charging dock only 2, self-emptying station 12, all-in-one station 78. The middle all-in-one model costs $799. More on what you get with each kind is in our guide on [what to look for](https://bestatbest.com/us/blog/what-to-look-for-in-a-robot-vacuum).

## What happens during a clean?

ECOVACS describes the order in five steps:

- Mapping: the robot works out where it is and creates or updates the map.
- Route planning: it picks an efficient path and watches for obstacles and stairs on the way.
- Cleaning: brushes, suction and, if fitted, the mop do their work.
- Adjusting: some models raise suction or lift the mop when they see carpet.
- Back to the station: it recharges and, according to ECOVACS, may carry on where it stopped if the battery ran low.

Looking after a Roomba? Read how to [clean a Roomba](https://bestatbest.com/us/blog/how-to-clean-a-roomba).

## Which model fits that?

Which navigation and which station you need depends on your home. These are the best-ranked models on sale now:

| Ranking | Model | Station | Today's lowest price |
|---|---|---|---|
| number 1 in our ranking | [Roborock Qrevo Edge 3 Pro](https://bestatbest.com/us/robot-vacuums/roborock-qrevo-edge-3-pro) | all-in-one station | $999 at Roborock (brand store) |
| number 2 in our ranking | [Roborock Saros 20 Flow](https://bestatbest.com/us/robot-vacuums/roborock-saros-20-flow) | all-in-one station | $1,699 at Roborock (brand store) |
| number 4 in our ranking | [Dreame Matrix10 Ultra](https://bestatbest.com/us/robot-vacuums/dreame-matrix10-ultra) | all-in-one station | $1,799 at Dreame (brand store) |
| number 5 in our ranking | [Roborock Qrevo CurvX](https://bestatbest.com/us/robot-vacuums/roborock-qrevo-curvx) | all-in-one station | $949 at Roborock (brand store) |
| number 6 in our ranking | [Dreame X60 Ultra](https://bestatbest.com/us/robot-vacuums/dreame-x60-ultra) | all-in-one station | $1,349 at Dreame (brand store) |

On sale today: 92. Highest ranked: Roborock Qrevo Edge 3 Pro ($999 at Roborock (brand store)). To match the choice to your home, use the [advisor](https://bestatbest.com/us/robot-vacuums/advisor).

## Frequently asked questions

**How does a robot vacuum know where to go?**

It uses sensors such as LiDAR or cameras to map your home. On that map it plans a route and avoids obstacles, according to ECOVACS and Dreame.

**What is the difference between LiDAR and a camera?**

A laser maps precisely and also in the dark, while a camera recognizes what is on the floor but needs light. Many newer models use both.

**Can a robot vacuum also mop?**

Some models can. They have a water tank and mop pads or a mop roller. Not every robot mops, so check the model.

**What does a self-emptying station do?**

It sucks the robot’s dustbin out into a larger bin or bag in the station, so you empty by hand less often.

**Will a robot vacuum fall down the stairs?**

A robot has cliff sensors that look down. They make it stop and turn away at an edge, writes ECOVACS.

## Sources

- [ECOVACS: How does a robot vacuum work?](https://www.ecovacs.com/au/blog/how-does-a-robot-vacuum-cleaner-work)
- [Dreame: LiDAR navigation in robot vacuums](https://www.dreametech.com/blogs/blog/lidar-navigation-robot-vacuum)
- [Dreame: LiDAR vs vSLAM navigation](https://www.dreametech.com/blogs/blog/lidar-vs-vslam-navigation)
- [Dreame: The parts of a robot vacuum](https://www.dreametech.com/blogs/blog/robot-vacuum-parts)
- [Dreame: Are self-emptying robot vacuums worth it?](https://www.dreametech.com/blogs/blog/are-self-emptying-robot-vacuums-worth-it)

Page: https://bestatbest.com/us/blog/how-does-a-robot-vacuum-work