How do Robot Vacuum Cleaners Work?

Joins us as we answer How do Robot Vacuum Cleaners Work?

Robot vacuums have come a long way in just the last few decades, transforming from a niche product that worked sometimes to one of the fastest and most efficient ways to almost never have to handle the vacuuming yourself ever again. But how do robot vacuum cleaners work?

Robot vacuum cleaners have spinning brushes to bring both large and small debris to a rolling brush in the center. This rolling brush lifts the debris from the floor as the motor sucks it the dustbin. The robot will have many sensors onboard that work in a similar way to echolocation to stop it bumping into objects or falling down the stairs.

But there is much more

These little modern marvels can be found zipping across floors in what appears to be a pretty random pattern in smart homes all over the world, but there is a method to this madness. These patterns are anything but random and allow the top-tier robot vacuums to provide clean, consistent, and efficient results every time you fire them up.

Below we dig a little deeper into how robot vacuums work, how they navigate, and how pioneering new technology is helping to make already pretty impressive robot vacuums even more successful.

Let’s dig a bit deeper into how robot vacuum cleaners work 

In the most basic of terms, a robot vacuum takes advantage of multiple onboard sensors to “map” the spaces that they are cleaning.

More affordable robot vacuums utilize sensors that work a lot like echolocation in a digital sense (of course), helping to bounce signals off of solid objects so that the robotic vacuum knows when to maintain its path and when to turn away from a collision.

Sensors are the main answer to How do Robot Vacuum Cleaners Work?

Slightly more expensive robot vacuums, such as the iRobot Roomba 7 or the Roborock S5 and S6, use advanced mapping tools that can include laser rangefinder systems, Wi-Fi systems, and other advanced technology to map your space over time so that they can create even more efficient routes that save battery life, save time, and result in cleaner spaces all at the same time.

Below we go under the hood of robot vacuums and learn a little more about these different sensors and mapping solutions.

Robot vacuums “See” with Onboard Sensors

Your vacuum is going to need to have some real freedom of movement if it’s going to clean your space effectively, but it also needs to avoid obstacles like furniture, walls, stairs, and a whole host of other physical objects that would either stop the robot vacuum in its tracks or (potentially) cause damage if there was a collision.

A variety of different sensors are built right into the main processing unit of every robot vacuum at every single price point. Some of the more expensive options include more advanced and more delicate sensors, but at the end of the day the odds are pretty good that your robot vacuum is going to include:

  • Obstacle sensors
  • Cliff/drop sensors
  • Wall sensors and
  • Wheel sensors

Obstacle sensors 

Obstacle sensors are easily the most active sensors onboard a robot vacuum.

Everything in your home that isn’t a flat surface to be cleaned is something that your robot vacuum will have to contend with, and these sensors allow your robot vacuum to make the necessary adjustments to get around these obstacles without leaving big gaps in its cleaning path.

Many of these obstacle sensors are located near the perimeter of the vacuum itself. Some of them are hardwired into the “buffers” that surround a robot vacuum, allowing the vacuum to take minor collisions in stride while immediately sending a signal to the wheels and the onboard navigation to make a course correction.

The new direction is going to be determined by a series of complex calculations that have a lot to do with where the contact was initiated on the sensors themselves. Contact with a bumper on the right, for example, is going to have your robot vacuum turning (to some degree) to the left.

Cliff/drop sensors 

These are designed to protect your robot vacuum from tumbling down a set of stairs, from falling into a sunken living room, and generally just to stay upright rather than find itself in a sticky situation or accident.

The sensors are built into the safety system of robot vacuums and are almost exclusively found on the bottom of the robot vacuum itself. Cliff/drop sensors are constantly measuring the distance between the sensors to the floor that the vacuum is cleaning, using infrared signals to make sure that the coast is clear and the path ahead is safe.

If these IR signals are not returned within a predetermined amount of time the robot detects that there’s a cliff or a drop off ahead of these sensors, causing it to do an about-face and to “remember” that there is danger in that part of the space.

Wall sensors

Wall sensors are used to protect your robot from colliding with your walls (obviously), but are a lot more commonly used to help your robot follow along with these permanent structures and obstacles so that your vacuum can provide a more consistent and efficient cleaning result.

Wheel sensors

These are designed to take advantage of light measurements that track wheel rotation, figuring out how frequently wheels are turning, how much they are turning, and how much space has been covered by a vacuum during an individual cleaning session.

Mapping Solutions Are Cutting Edge

More modern (and usually more expensive) robot vacuums aren’t just going to include the sensors that we highlighted above for navigation but are also going to include “self navigation” systems that rely on dedicated mapping technology.

Different manufacturers have different mapping solutions that they build their vacuums around, but most of these proprietary platforms have a lot in common.

Almost all of them take advantage of onboard digital cameras that are constantly snapping photos and analyzing pictures of walls, doorways, obstacles, and other important “landmarks” that make the map of your entire home more and more accurate over time.

Other vacuums include Light Detection and Ranging (LIDAR) technology, a technology that uses lasers and rangefinder systems to measure the distance between objects and obstacles in your home and the vacuum itself.

All of this data is collected on the fly and then transmitted back to the docking unit that maps the spaces the vacuum has cleaned – improving those maps over time with each cleaning session. These maps can be incredibly precise and guarantee that your vacuum is going to cover every square inch of your home that it can get to.

Best of all, the high-end robot vacuums that use mapping technology get smarter over time. As the vacuum “fills in the blanks” while it cleans your home the system looks for ways to more efficiently cover the space the vacuum handles.

After a dozen or so cleaning sessions your robot vacuum will have learned the most efficient way to clean your space, guaranteeing that every nook and cranny gets vacuumed but that you use less battery power, less time, and have to listen to your robot vacuum cleaning up glass as well.


Will a robot vacuum mean I never have to vacuum again?

Sadly not. While the tech has undoubtedly come on leaps and bounds in recent years, don’t get rid of your upright quite yet. What these machines are great for is keeping on top of the vacuuming situation, but there will be places they can’t reach or stubborn areas they may struggle with. You will certainly be vacuuming less, but you may still need to take over from time to time

How do robot vacuums find their HQ when they are done?

Most modern robotic vacuums include a wireless connection between the vacuum itself and the docking station that acts as a charging system/storage solution for the vacuum. When the vacuum has finished cleaning (when the battery is low) a signal is sent out between the HQ and the vacuum itself in the vacuum follows that signal back home before docking.

Do robot vacuums learn over time?

More expensive and more advanced systems definitely will. Those with mapping technology learned smarter routes to vacuum your space more efficiently.

Do you need Wi-Fi for a robot vacuum cleaner?

Typically, a robotic vacuum cleaner does not require Wi-fi to clean. By simply clicking a button, it is expected to start cleaning. However, some robot vacuum cleaners have mobile applications that require users to connect to the Cloud to enable features in their smart home like cleaning scheduling, push Notifications, tweaking cleaning preferences, etc. 

How often should you run a robot vacuum cleaner?

Most robot vacuum cleaners can be scheduled to run as often as once a day or several times a week.

How much dirt can a robot vacuum cleaner hold?

Robot vacuum cleaners come in different sizes, but even the smallest of them can hold up to a days’ worth of dirt. The sizes of the bin cups range from 300ml – 1000ml. Fortunately, there are robot vacuum cleaners that can empty themselves, so you don’t have to worry about taking out the “trash”.

Do robot vacuum cleaners scratch Hardwood floors?

Seeing that most robot vacuum cleaners are designed to transition from different floor types, a robot vacuum cleaner should ordinarily not scratch hardwood floors. However, some specific types have been known to cause scratches to wooden floors, so it is best to take care when purchasing one.

Are robot vacuums infallible?

While the technology “under the hood” of robot vacuums has grown by leaps and bounds over the last 30 years or so these helpful little appliances still have a tough time with electrical cords, “low bridge” furniture, and dealing with heavier levels of dirt and debris as well as stains.

What should I call my robot vacuum?

Funny you should ask – we have your answer right here.

You May Also Like

About the Author: matt