While still considered a bit of a gimmick by technophobes, there's no question that robot vacuum cleaner technology has come on in leaps and bounds, specifically during the past two years. Today's best robot vacuums combine high-tech engineering, clever electronics, software programming and even AI (Artificial Intelligence) to navigate spaces, clean surfaces and avoid obstacles without the user requiring a degree in physics or a diploma in the art of instruction manual reading.
Given that a robot vac's sole task is to keep a home's entire floorspace spick and span on a regular basis, it requires a lot of advanced onboard technology to help it navigate around the home without missing sections of floor, bumping into walls and furniture, venturing into rooms you'd rather it didn't or getting lost.
Hence, every robot vac today is equipped with an array of sensors and, in most instances, a LiDAR detector and an RGB camera to see its world much like a human (if you're in need of a more basic introduction, hop to the bottom of the article for a look at the anatomy of a robot vacuum). Let's have a look at these clever navigational aids in more detail.
How do robovacs navigate?
Robot vacuums use a combination of technologies to navigate a home, map its surroundings, avoid obstacles and ensure they cover the entire cleaning area. Sensors are the eyes of a robot vacuum cleaner.
These include infrared sensors for detecting obstacles and edges, LiDAR to map a floorspace by measuring distances using laser technology, vSLAM technology that relies on a camera to highlight the area directly in front of the robot, cliff sensors for identifying drops such as staircases, dirt detection sensors that recognize heavily-soiled areas for focused cleaning and, in the case of some budget models, bump sensors that trigger when the robovac encounters a solid obstacle, prompting a change in direction.
LiDAR
When it comes to initial mapping of a home and navigation in general, most high-end robot vacuums use LiDAR (Light Detection and Ranging). Essentially, the robot emits a cluster of laser beams from the raised puck in the center of the bot. These are reflected from objects in its vicinity. The system detects the returning beam, and uses a ToF (time of flight) sensor to figure out how far away the object is. It can then use all this information to build up a detailed and precise 360-degree map of an area and the objects in it.
LiDAR is far and away the fastest and most reliable form of navigation. You can even watch the robot's progress live on the robot's accompanying phone app. However, a minor downside is that the raised puck makes the robovac taller, meaning it won't be able to venture under particularly low furniture.
There are a couple of other downsides to using LiDAR for navigation. One is that LiDAR treats any solid-looking object as an obstruction, even if it's just a piece of soft material. That means it won't punch through bed and sofa valances. The solution? Lift and tuck any valances before the robot goes out. Mirrors, too, have been known to reflect the LiDAR's laser beam, which can cause an inaccurate sense of location and distance, but I've personally never experienced that issue and I have mirrors galore.
vSLAM
Some robot vac manufacturers use vSLAM (Visual Simultaneous Localization and Mapping) technology for navigation. The most notable brand to continue to use vSLAM is iRobot and its Roomba range.
vSLAM navigation uses the robot's camera, which means there's no need for a central raised puck – as you can see on the Roomba Combo 10 Max below. One benefit of this is that it can have an overall lower profile and venture places taller bots can't.
According to major robot vac manufacturer Ecovacs, "vSLAM gives a robot vacuum the ability to navigate a home using a camera... to capture images of its surroundings and identify specific points, like corners or edges of furniture. The device then uses these points to triangulate its 3D position and create a map of your home."
On the downside, vSLAM requires significant computational power, so it's nowhere near as quick and efficient as LiDAR. Also, vSLAM-equipped bots tend to bump into furnishings during their cleaning routines and they have a habit of vacuuming in an erratic fashion. In contrast, LiDAR models normally clean in a logical up-and-down pattern.
Moreover, vSLAM performance can degrade in low-light conditions or in environments with few distinguishable visual features. Although most vSLAM units will also have an LED headlight, it's still worth switching on the lights in the darkest areas of the home or the robot may struggle to find its way around or successfully navigate back to its charging dock.
How do robot vacuum cleaners avoid obstacles?
When it comes to obstacle avoidance, many higher-end models now carry cloud-based directories of the types of obstacles found in most homes, including specific objects such as phone cables, small toys and, in some rare cases, even pet waste. When the robot's front camera spots something, the bot should skirt around the object. It might even take a photo of it to ask the user if this particular object is normally a feature of the home, so it knows to avoid that area in future.
Given the hypersonic speed with which the world of autonomous robotics is advancing – specifically in China where most of the world's most advanced home robots come from – some major industry-leading manufacturers like Roborock, Ecovacs and Eufy have started releasing products that use advanced cameras along with Artificial Intelligence and machine learning to help with better navigation and, specifically, obstacle avoidance.
For example, the Roborock Qrevo Curv (above) uses a Reactive AI navigation system. In my tests, I found it effortlessly avoided most obstacles above two inches in height, as well as automatically adapting its route when anything was in its way.
Advanced obstacle avoidance
Roborock's StarSight, for instance, is a new type of navigation system that uses 3D Time-of-Flight (ToF) technology and dual-light solid-state LiDAR to help some of its robots navigate and map their surroundings as a 3D environment.
Similarly, Ecovacs' advanced AINA 2.0 Intelligent Navigation Model provides real-time navigation and obstacle avoidance that combines deep learning and reinforcement learning technology to improve its navigation prowess.
Likewise, the excellent Eufy S1 Omni Pro uses a 3D MatrixEye obstacle avoidance system that includes Active Binocular Infrared Imaging Technology and an RGB camera that, according to Eufy, 'mimics human vision'.
Yes, there's a lot of PR jargon in these descriptions, but that's the nature of the marketing beast. All you need to know is that most of this tech actually works, albeit in the background, to help keep your floors – both hard and carpeted – looking swish and swanky.
Anatomy of a robot vacuum cleaner
Robot vacuum cleaners – often called robovacs or vacbots – have revolutionized home cleaning by providing a hands-free solution to maintain tidy floors so you don't have to. Although the fact they can't handle things like stairs means they won't be able to completely replace the best vacuum cleaners of the manual variety, they still do a sterling job of keeping on top of floor dust and pet hair.
The average robot vac comprises a high-powered battery, a suction motor with brush roller (usually rubber for efficiency and longevity), a spinning side sweeping brush for corners and along skirting boards and a small half-liter bin to contain all the detritus it collects. The latest breed of hybrid models can mop as well as vacuum, so will have either a fixed mop pad or two circular discs that spin to dislodge dirt.
The best robot vacuums also come with a large charging dock that sucks the waste from the robot's bin into a much larger dustbin that can be disposed of when full. If you have pets, a large home with lots of foot traffic, and/or don't fancy the thought of having to quite regularly empty the robot's tiny bin yourself, always plump for a model with a cleaning station. (If you're looking for the best robot vacuums for pet hair, it's worth prioritizing a model that has a self-empty base.)
Finally, every robot vac on the market comes with its own phone app, from which you can control the bot. Exactly what you can do here depends on the type and price of robovac you're working with, but they'll typically allow you to set cleaning schedules, customize the type of cleaning needed, create no-go zones and virtual walls, plus a myriad of other customization options to suit your floorplan layout.
