Husqvarna, Ecovacs & Co.: robot lawn mowers can do that without a boundary wire

Lawn robots have been found in German gardens for years and the number is increasing. Rightly so, because once installed, the electronic gardening aids promise a lot of time and work savings by mowing the lawn independently. What quickly saves several hours a week in summer, depending on the size of the lawn, requires good planning and a lot of time and effort, at least during installation – until now. A new generation of robotic lawnmowers promises a remedy, which does without this perimeter wire and instead uses sensors such as ultrasound, GPS, cameras and AI.

So far, the boundary wire has been used on robot lawn mowers so that they know which area they are not allowed to leave or which they are not allowed to enter. This previously required the precise laying of a wire around the area to be mowed, which can take several hours depending on the type of laying on or under the lawn and depending on the size. We have summarized more about this and what is generally important for robot lawn mowers in our guide Husqvarna, Gardena, Stihl: The best robot lawn mower for every lawn size.

The latest robot lawn mowers no longer need this boundary wire. Instead, they rely primarily on the global positioning system GPS and sometimes on additional flares, ultrasound, ToF sensors (time of flight) and cameras paired with AI (artificial intelligence). This makes it possible for the models to navigate and mow with an accuracy of a few centimeters without unintentionally plowing up the flower bed.

The cameras in some of the new robot lawn mowers literally allow the device to get a picture of its surroundings. The device uses this to orient itself and recognizes obstacles such as garden furniture, people or animals in the path. In addition, the cameras can also be used as a mobile security system on some models. The mowers can film detected people while patrolling the property or standing in the charging station, thus deterring potential thieves.

Objects, people and the environment are recognized via the cameras mentioned, but the robot must also understand what it sees. AI ensures that the mower can process the images and, for example, replan its route in the event of an obstacle without bumping into it or even driving over it beforehand. This not only increases the autonomy of the robot, but also the protection for humans and animals.

In fact, the work for the initial setup is reduced, but only limited in terms of time. The basic steps, such as assembling and setting up the charging station, remain the same, but the sweaty and time-consuming act of laying the wire is no longer necessary. In its place is the setup and connection with the robot’s app, which users of a vacuum robot (theme world) will be familiar with and should pose few problems. In addition, GPS antennas and/or signal beacons need to be set up – sometimes in the immediate vicinity of the charging station, sometimes distributed in the garden or only roughly near the mowing area.

This is followed by learning the mowing surface. In almost all currently available models, the mower is maneuvered with the smartphone like a remote-controlled car along the edge of the mowing area until you get back to the starting point. This allows the robots to recognize their future work surface. This process takes around 20 to 60 minutes on average, depending on the robot and the size of the lawn, as well as the boundaries of beds or ponds. Some models then require an exploratory tour without mowing, which then runs independently. The GPS mower is then ready for operation.

In addition to the labor savings during setup, robotic lawnmowers that do not require a boundary wire offer other advantages. Without exception, they drive in straight lanes and thus create a very neat cutting pattern – almost like on the soccer field. The alignment of the lanes can be freely selected with some devices, so that you can mow exactly parallel to the front of the house. In addition, with some models (already now or planned for the future), individual zones can be created that can be mowed at different heights or often – similar to robot vacuums. In addition, thanks to the app, you can see exactly where the robot has already been, how long it still needs and much more. This usually works in more detail than with previous robot lawn mowers, since the GPS-supported models know exactly where they are and where they have already been.

Currently, the wire-free robotic lawn mowers we’ve tested or are currently testing offer some obvious benefits, but they’re not perfect. A downside is the reliance on a good GPS signal. If the sky is covered with a dense cloud cover or the robot moves under thick foliage of trees or bushes, the GPS signal can become so weak that the robot stops working for safety reasons. But that almost never happens with the latest models.

Another major disadvantage: Currently, hardly any GPS robot lawn mower allows the subsequent adjustment of the mowing map. It is true that some variants (already now or only planned for the future) make it possible to subsequently record new mowing areas or to create restricted zones for beds at a later date. According to the current status, revising a map that has already been created only works with one model: the Marotronics Alfred (test report). All other robots require the customer to relearn the card from scratch if, for example, he finds that the robot keeps getting stuck at a certain point on the card.

Another disadvantage is the edge trimming – even more so with GPS-based robots than with those with a perimeter wire. Because while owners of wire models can always move the cable a few centimeters until the robot cuts the perfect edge, the majority of current GPS mowers cannot (yet) do this. Since they mow with centimeter, but not millimeter precision, it is better to always leave some grass at the edge instead of the expensive mower sinking into the pond or damaging the beds.

Last but not least, the high price of these technically advanced robot lawn mowers remains. At 1500 euros and more, they are usually several times more expensive than wired robotic lawnmowers. As always, new technology has its price.

Basically, there are still robotic lawnmowers that try to stay on the green using a lawn sensor. However, we do not want to go into them in this article, as they are generally only suitable for tiny lawns and are not considered to be overly reliable. Instead, we focus on models that work according to the technique already described in the article.

One of the latest models of this type is undoubtedly the Ecovacs Goat G1, which is currently being tested at the time of publication of this article. It relies on GPS positioning, AI with a front-facing and additional all-round camera, additional signal flares in the garden and a really good app. Adjustment of the mowing area and expansion are currently not possible, but the “goat” makes an excellent impression in terms of navigation and lawn cutting.

The Segway/ Ninebot Navimow describes itself as the first of its kind, even if that is not entirely correct – the Marotronics models Alfred and Ardumower have existed for much longer, even if they are not large-scale models. The Navimow also uses GPS and additional sensors such as a camera to create mowing areas easily and intuitively via an app. In terms of price, the smallest version of the Navimow is even slightly below the Goat G1.

The Marotronics Alfred (test report) is aimed more at interested parties who want to lend a hand with assembly and have as much freedom as possible in operation, including their own programming. This requires a lot of know-how, but in return it offers the most options – even without programming knowledge. The Alfred is currently the only GPS mower whose mowing map can be meticulously adjusted by the user at any point. However, the device does not offer cameras “ex works” and the app was rather unintuitive, at least at the time of testing at the end of 2022.

The Ecoflow Blade immediately catches the eye with its futuristic design, which has little in common with a conventional robotic lawnmower. In contrast to the competition, the robot lawn mower offers two rigid wheels at the front, each installed at 45 degrees to the direction of travel, and an optional collection container, with which the device can pick up leaves in autumn. The Ecoflow Blade is scheduled to hit the market at the end of April 2023.

The well-known mowing robot professional Husqvarna has presented its Nera series, which for the first time can mow wirelessly using GPS and is not aimed at companies as before, but at end customers. The market leader in robotic lawnmowers is now also relying on this new technology. The Nera models should come onto the market in the course of 2023 and cost from around 2800 euros.

Like the Ecoflow model, the Mammotion Luba, financed via Kickstarter, relies on an atypical lawnmower design, which is intended to remind of a sports car. The most expensive version offers four-wheel drive and is said to be able to mow up to 5000 m². The delivery of the Luba models is expected for the end of May 2023.

The future is wireless mowing, that much is clear. With their simple setup methods and the extensive setting options in the respective app, robot lawn mowers are finally following the example of robot vacuums, making work a lot easier for garden owners. 2023 is the starting year of this “new” technology and even if the first available models do a lot right, they are far from perfect. They are aimed at early adopters who want to try out the new technology and afford it despite the high prices. In any case, it should be taken into account that there is always a need for manual help, especially at the beginning.