With such a large number of robot cleaners available on the market, it’s easy to get lost in the numerous features that each one might have. However, there are certain technologies and features that future buyers should be aware of before diving in. Some of these features come standard in almost every robot vacuum. Others are tacked on as bonuses, or as methods of trying to make the product more useful, efficient, and ultimately more attractive to buyers. What you’re looking for will depend on what you’re willing to pay, as well as what is actually useful to you.
It’s best to keep in mind that no robot vacuum comes with everything on this list, although some of the highest-cost models from the top brand names may come close. It’s best to keep in mind, however, that you may not need everything in order to get the best benefit out of your robot vacuum, and that simply having all of the latest bells and whistles does not make a robot vacuum effective. For evidence of this, check out our individual reviews of different robot vacuums. This should help you sift through the details better as well.
One of the primary features in all robot vacuums is known as “avoidance technology”. This is a combination of sensors all over the robot’s body that help it to avoid different obstacles. At a bare minimum, a robot vacuum will, and should, include these two avoidance technologies:
Every robot vacuum maker includes cliff sensors as a standard practice now. These sensors, which are placed on the underbelly of the bot, are located near the front and sometimes back end of the machine. The cliff sensor is usually an optical sensor that determines height — similar to the optical laser sensor on a digital mouse. The sensor will determine how far the robot is from the nearest surface. If the robot is about to go over a cliff (example: stairs), it flips a switch or impacts the software and causes the robot to reverse immediately. Most robot vacuums have a cliff sensor tuned to within a few inches. This allows the machine to still go over small bumps, but avoids disastrous falls down stairs.
Bumpers are often included on the front side of a robot vacuum that allow it to recognize when it has hit an object. Usually padded, this lets the robot know it needs to move in another direction. The bumper sensors are mechanical, activating only when the machine has physically run into something. These are also some of the cheapest types of sensor to include on robot vacuum. The most effective bumper sensors are combined with mapping technology.
There are additional kinds of sensors you may find on a robot vacuum beyond these. This includes other infrared sensors that help determine what objects in the room that should be avoided, and digital and infrared cameras that take actual images and photographs of the room for the same purposes. Some very high-end robots may even use ultrasonic frequency technology to map rooms and avoid objects.
Joined with the avoidance technology on robot vacuums is the mapping technology. It is important to note that while all robot vacuums have avoidance technology, not all robot vacuums include mapping technology. There are significant benefits to purchasing a vacuum with mapping technology, including:
Increased cleaning efficiency
Better object avoidance
More advanced cleaning patterns
Mapping technology is typically a combination between hardware and software. The hardware used to map the room is often the same as that which is used for object avoidance. Joined with software that creates a digital map of each room, the robot vacuum will remember the room’s layout and create regular cleaning patterns. If a room’s layout changes, the maps are updating or renewed for continued efficiency. Note, however, that robots with mapping technology often come at a higher price.
There are two, primary methods for mapping technology used in robot vacuums:
Digital cameras (visual mapping)
There are differences between how these two forms of mapping technology work, and with their overall effectiveness. Laser mapping, while effective in most cases, has an issue with shadows. It can also give false indications of obstacles, and is not always entirely accurate regarding the size of objects in the room, or distance from those objects. Viewed on a screen, one may see why. The presentation shows that the image created is not entirely clean.
Digital cameras offer an advantage in that they give real-life positioning for the robot. The newest, and perhaps best, mapping technology using visual means is known as VSLAM, or Visual Simultaneous Localization and Mapping. The benefit of this is that the robot can keep track of where it is, while also mapping out new terrain, using real, digital imagery. This allows the robot to avoid objects much better, remember where it has been much better, and clean much faster and more efficiently. Robots that use digital visual mapping are more expensive purchases.
The second most important feature of a robot vacuum is its ability to clean. We call this the second most important, given that a robot vacuum needs to be able to move around effectively without destroying itself first and foremost. After that, a robot vacuum is measured on how effectively it can actually clean.
This is also the area that most robot vacuum companies pour the majority of their features and their money. It is also the aspect of robot vacuums that receives the most attention during marketing campaigns, as it is the function most consumers are likely to care about. Here you will find all of the tiny details regarding what can and does go into robot vacuums.
The most common cleaning features on a robot vacuum include, but are not limited to, the following:
Traditional brushes (bristle): Most robot vacuums will include a brush that is very similar in design to what you will find with a traditional vacuum. That is, a central dowel with plastic or nylon hairs inserted into it that help sweep up dust, dirt and other loose materials into the receiving basin. Most lower end robot vacuums will utilize a traditional brush style.
Bladed brush: Bladed brushes shirk the traditional bristle design, which mimics a regular broom in place of angled rows of rubber “blades”. These blades are usually designed to help clean up pet hair, which commonly gets stuck within bristle brushes, but will not stick inside of blade brushes by design.
Combination brush: A combination brush combines the rubber bladed design with traditional bristle design. This design is meant to bring in the best of both worlds, as the common bristle design is much better at sweeping in smaller dirt and dust particles.
Brushless design: Although rare, the brushless design works on an interesting principal. Essentially operating like a suction hose attachment on a regular vacuum, robot vacuums with this design include no main brush. The suction area is comprised of a small hole. Typically, these designs will include side whiskers to help move material in toward the hole, which is usually centrally located. The primary flaw of this design is that it does not work well on rugs or carpets, as it lacks the agitation of a main brush.
Brush location: The location of the primary brush is easily overlooked. However, where this brush is located can make a difference in the overall effectiveness of the robot vacuum. There are three potential locations for the primary brush: the front, the middle or the back. The most common location on the majority of robot vacuums front area placement. Frequently, you may find the brush and suction area in the center of the machine. On very rare occasions, robot vacuum designers have placed the brush on the back.
The key flaw to placing the brush directly center or in the back is the fact that the machine will roll over a significant amount of material before anything gets to the brush. Problems arise in which dust and other material will collect on the underside, and will need cleaning after a time. On some occasions, this has caused the dust and other materials to actually block sensors located on the bottom. This can lead to a malfunction in operation.
Suction Strength: If a robot vacuum company is downplaying its vacuum’s suction strength, the likely reason is that the suction strength is poor. Suction strength can be determined by the strength of the motor and the design of the air chamber and fan. These can influence how strong of a suction is created. Many of the lower-end robot vacuums will use smaller, low-powered and cheaper motors. Low-powered motors tend to be passable on hard surfaces, but mostly ineffective or poorly effective on carpets and rugs where stronger suction is needed. They will also have issues getting dirt and other materials in one pass, and will need to make multiple passes before everything is collected. Meanwhile, stronger suction robot vacuums will be noticeably louder and may be overly disruptive. The higher-end robot vacuums have several strength settings, letting you change how strong the motor is pulling in air.
Dry/Wet mop functions: Many robot vacuums include what is known as a “dry mop”. This is typically a cloth attachment on the back of the machine (or front/center for machines with a central of back suction area). Often a microfiber cloth, the purpose is to sweep up extra loose dirt and dust that the suction misses. Some include a “wet mop”, a moistened version of the dry mop that is intended to help clean the area more thoroughly. In essence, this treats the robot vacuum like a Swiffer.
Unfortunately, no robot vacuum maker has created a robot vacuum where the wet mop is entirely useful. The reason for this is the lack of applied pressure. In order for a wet mop to be effective, downward force must be applied. In today’s market, no robot vacuum that includes a wet mop also has the ability to apply this downward force to the wet mop area. This may change in the near future. However, if you are considering a robot vacuum that is touting its wet mop feature, take this advertisement lightly.
Storage bin: All vacuums need a location to store material that is sucked into the machine. All robot vacuums are bagless, and typically include a detachable storage bin. Because robot vacuums are bagless, they will usually include a filter (often a HEPA filter) for catching very fine dirt particles on the exhaust section. Some robot vacuums have a reusable filter. Others do not. If you are not looking for a machine that needs new filters ordered every so often, invest in one with a reusable filter.
Side brushes/whiskers/dust brushes: The side brushes, also known as “whiskers” on a robot vacuum, are a relatively new invention. However, they have become standard on almost all robot vacuums due to their effectiveness. These additions often sit on the front side of a robot vacuum, and spin inward toward the center of the machine. They extend outward toward the side and front, with the purpose of pushing dirt and loose material into the machine’s brush area. Additionally, the side whiskers help robot vacuums overcome a severe limitation: Getting close to baseboards and walls. This has always been an issue with regular vacuums, which overcome this with attachments. However, robot vacuums must overcome this issue without added attachments. Side whiskers were the solution and have proven mostly effective.
One of the interesting updates to robot vacuums is the inclusion of wireless connectivity. Many high-end robot vacuums will include their own phone or tablet applications that can connect mobile devices directly to the robot vacuum through an internet connection. This allows for a range of mobile connectivity solutions, including scheduling, monitoring, push notifications and even remote control. Although rare, it is realistically possible to get a live video feed from some robot vacuums that include digital cameras for navigational purposes.
Many other robot vacuums include a very basic radio frequency connection. These robots will come with a simple remote control and several buttons for stopping, starting, and scheduling. Many users go for this option to avoid having to constantly get up and down to move the robot around. Robots that allow for limited remote control also add a certain fun factor to the mix, while also allowing the user to take control when the robot’s programming can’t seem to overcome certain obstacles. The remote control function also helps for when the cleaning pattern fails to effectively clean an area.
The size and the shape of a robot vacuum can have a significant impact on how effectively that robot can clean. There are several factors to consider when choosing a robot vacuum based on its size and shape.
Round robots. This design is the most common, popularized by the industry-leading maker, iRobot. iRobot’s Roomba vacuum was not the first robot vacuum on the market, but proved to be the most commercially viable one. Most other companies entering the market followed suit on this design scheme. Round robots benefit from being able to get around areas well, and with the inclusion of bumper sensors, can avoid making too many hard impacts to furniture. They are extremely limited, however, in their ability to get to corners and walls. Without the aid of side whiskers, their physical shape makes getting to walls and corners a physical impossibility.
Squared robots. The squared robot design is very uncommon, but extremely effective. This design is more closely associated with Neato Robotics and their Botvac. This design makes getting into corners and close to walls easy for the robot. The inclusion of side whiskers means that squared robot vacuums can get within millimeters of baseboards and into corners in ways round robots cannot. The limitation on these bots is that the squared design is more likely to get stuck between chair legs.
Charging and Auto-Return
One of the primary selling points for the Roomba was its ability to return to its base on its own. This feature alone is what helped make the robot vacuum a hot-ticket item. Currently, this is a standard for robot vacuums. Ones that do not include this feature typically will not sell, for good reason. The auto-return feature on a robot vacuum is often achieved through a radio frequency signal. The robot will locate its base with this signal, and guide itself back to the base when the battery begins to lose power. The percentage battery power that triggers this function depends on the robot. However, it is typically somewhere between 5-15%. The base should always be located somewhere unobstructed by other objects, and not influenced by other radio signals that would cause interference with the vacuum’s ability to locate its base.
The range which a vacuum can locate its base varies. Some robot vacuums have a range that is only a 5-foot radius outside of the base. Others can locate their base at much wider areas. Some higher end robot vacuums will include features that allow the vacuum to locate the base from any location. Typically, the bots will slowly back onto the base and onto the charger. Most are designed to finish the cleaning task they were assigned after the charging cycle is complete, and will go through a charge-clean-charge process until the cleaning task is done.
Battery power on a robot vacuum is extremely important. How much power your robot vacuum consumes to get the job done can be very limiting. Despite advances in battery technology, the reality is that robot vacuums are extremely power-hungry. Most average anywhere between 1 hour to 1.5 hours per charge. While this may sound like a lot of time for a traditional vacuum, a robot vacuum typically operates much slower than a human operator, and often much less efficiently. Likewise, most robot vacuums have limited suction power in order to avoid using up battery too quickly.
The best robot vacuums on the market can manage 2 hours of battery life. Buyers will be hard-pressed to find a robot vacuum that can manage over 2 hours. Those that can often sacrifice cleaning power to achieve this. This is a sacrifice many buyers are unwilling to make, especially if their house or apartment is carpeted or contains numerous rugs, where stronger suction is necessary for better results.
The amount, and type of accessories vary by robot vacuum. In most cases, the accessories available for a vacuum are primarily replacement parts, such as spare batteries, filters and side whiskers. Some robot vacuums also include barriers that will prevent the robot vacuum from entering certain areas.
Barriers will come in two forms: Barrier strips and light barriers. Barrier strips sit on the ground and prevent the vacuum from driving over them. When the vacuum hits the strips, it triggers the cliff sensor. This will force the vacuum to reverse direction and avoid going over the strip. It is simple, cheap and effective. Light barriers are uncommon, but effective. This are placed in a doorway, and send a light signal straight across. The robot vacuum’s navigational sensors will “see” the light barrier and will not cross into the room or area guarded by the barrier.
Most companies that sell accessories sell only replacement filters and side whiskers. A small handful sell batteries. Based on our research, only one company, bObsweep, sells almost every single piece of technology in the robot vacuum except the motherboard. This makes the bObsweep a tinkerer’s dream. Most other robot vacuum companies are extremely protective of their equipment and technology.