Robot lawnmowers have finally become good enough to take a significant chunk of work out of yard maintenance, but they are still not set-and-forget machines. The latest generation of autonomous cutters can produce a noticeably healthier lawn while running quietly around the clock, yet they still need supervision. After testing five models on a challenging property, it is clear that the technology has made big strides—and that no automower is perfect.

My test grounds are a flat, three-quarter-acre yard in coastal South Carolina with sandy soil, centipede grass, and a lot of trees. This summer, I ran five robots across the property. Things went much better than last year. The biggest improvement was navigation: the bots mostly stopped getting stuck. My lawn has never looked better. My spouse, who had sworn off robot lawnmowers after an earlier user-error incident, is now a convert, and the riding lawnmower has been idle for over a month.

The consistency of robot mowers is impressive. Running daily and shaving just millimeters at a time, these mowers have created a noticeably lusher lawn. I walked out on it barefoot this morning—something I have never done before. The best part is that they work quietly around the clock, without bothering my pets, the wildlife, or the neighbors. I also love the professional-looking lawn lines they make.

What’s better

The key upgrades this year are network RTK navigation, fallback navigation systems, and improved all-wheel-drive to tackle rougher terrain. RTK—real-time kinematic positioning—is the satellite positioning tech most automowers switched to over the last few years as they ditched boundary wires. It uses stationary ground-based reference stations, along with GPS, to provide very precise location data down to a centimeter or two. It is used for surveying, drone navigation, and anything that needs that fine level of precision.

Every mower I tested, apart from the lidar-based Dreame, comes with its own RTK antenna that needs to be installed in your yard with a clear view of the sky. Trees, a neighbor’s house, or your own roofline can all block the signal. In my previous testing, I did not get a single RTK mower to run successfully in my backyard, where I have very spotty GPS coverage. That changed with this new crop.

Most of these mowers now offer NetRTK as an option. This taps into a network of existing RTK reference stations through a cloud connection, and requires a Wi-Fi or 4G connection on the mower. Most worked out of the box without me needing to install the antenna, but you will need to check if your house is covered, as coverage varies. RTK mowers now also use a secondary navigation tech such as lidar or vSLAM to keep on track when the signal drops. This improvement in navigation, plus bigger, more capable machines, meant I no longer spent my summer dragging confused mowers out from under oak trees.

What still needs work

However, automowers are far from perfect. These are autonomous machines with blades, and leaving them to their own devices comes with risks. One spent three days methodically destroying a patch of my lawn before I noticed. Another took out two outdoor extension cords. Several models dug sandpits in bare patches, and another tried to climb up a small tree.

Obstacle detection is better across the board, but it still has a long way to go. Hoses, cables, and cars are still a challenge. My family now knows to check under the wheels before driving away. No one has really solved gates yet, either. I still have to manually open mine to let the robot mow the full property. And while every manufacturer currently advertises NetRTK coverage as free for the lifetime of the device, there are obvious downsides to relying on a cloud service to mow your lawn. Automowers are also still expensive, and I have concerns around long-term durability.

Like their siblings, robot vacuums, there are myriad models on the market now. The right one for you will depend on the size of your yard and your landscape. To find the mower that worked best for me, I tested four top-of-the-line models with specs capable of tackling my challenging terrain and large backyard: the Husqvarna 420 IQ at $3,299, the Mammotion Luba 3 AWD 3000 at $2,799, the Navimow X430 at $2,499, and the Dreame A3 AWD Pro 2500 at $3,099.99. I also tried the entry-level Roborock RockNeo Q110H at $1,299 on my front lawn, which is more like a standard suburban lawn.

Also like robot vacuums, robot lawnmowers fall under the new FCC robot ban. While existing models can continue to be sold and supported in the US—including all the models reviewed here—the fate of new models is in question.

The robot I’d get for my yard

Segway Navimow X430

The Segway Navimow X430, priced at $2,499, is by far the best mower I tested. This 60-pound beast looks like Darth Vader’s dog, and it was the only mower I tested that did not get stuck once. Its 4WD wheels combined with impressive suspension rolled through potholes, over sticks and rocks, and even small tree branches. It navigated around my chickens and across the tall, uneven transition from my front yard to back yards—it was the only bot that could mow both in one trip with the gate open.

It uses a combination of RTK, vSLAM, and vision-based tech to navigate, and it covered my entire property without once getting lost or stuck. It features impressive xero-turn maneuverability, enabling it to pivot smoothly with no lawn damage. Its dual-disc, 17-inch cutting width covers more ground, and it was able to mow most of my backyard in under three hours—nearly twice as fast as most competitors. I really liked the remote-control mowing feature, which was handy for tidying up the edges of the lawn and more sensitive areas such as around flower beds.

The Segway’s speed does mean a few blades go untrimmed, and its rain sensing relies on weather data from the internet, which meant it often did not mow because it predicted rain that never came. Setting up the NetRTK was a bit tricky, mostly because I had to put the charging station in an awkward spot to connect to the GPS. It cannot be under an awning or up against a building, because the mower also needs a clear view of the sky.

A good lidar-based alternative

Dreame A3 AWD Pro 2500

The Dreame A3 AWD Pro 2500, priced at $3,099.99, is the best option if you cannot rely on RTK. Its lidar and camera-based navigation performed nearly as well as the Segway in my backyard, only getting stuck a couple of times. It does not need a clear view of the sky, so you can place it anywhere, and its sliding edge-cutting deck worked slightly better than the Segway’s EdgeSense feature in my testing. Beware that it is set to a fixed 1.2-inch minimum cutting height.

But in my testing, lidar was the least reliable navigation tech, and sometimes the A3 declared the job complete when it was not. Lidar robots do best in a fenced-in yard, as they can more easily get lost and wander off into your neighbors’ yard, something that never happened with the RTK robots. While the Dreame rarely got stuck, its turning mechanism was not as smooth as the Segway’s, and it dug several sandpits in various spots where there was no grass.

I do like its Garden Guardian mode, which uses the camera as a roaming security guard, and it can also identify when people cross its path and warn them that it is working. It has been mildly hilarious watching it surprise dog walkers passing by the front yard.

An expensive but reliable option for yards with no trees

Husqvarna Automower 420 IQ

Husqvarna’s Automower 420 IQ, priced at $3,299, is a good option for a standard yard. It has the longest warranty at four years, the easiest app and controls, and a modular design for longevity. It is 2WD, but its large wheels tackled uneven terrain well. It requires an RTK antenna and has the option of cloud-based RTK in some areas, but its backup navigation for satellite dead spots requires installing physical boundary wire.

I tested this in my neighbor’s yard using the physical RTK antenna, since they have fewer trees and clearer views of the sky. It navigated well, but it uses radar for obstacle detection and has no camera at all. This meant it was not as good at dodging objects as the others, and it ran into the bushes once and tried to climb a small tree.

But if you have a large, uncomplicated, tree-free yard, it is a good option thanks to Husqvarna’s broad support network, free-for-life cellular connectivity for both theft and NetRTK, and impressive performance.

More reliable navigation, but spotty software

Mammotion Luba 3 AWD 3000

The Mammotion Luba 3 AWD 3000, priced at $2,799, combines all three wireless navigation types—RTK, lidar, and vision—making it ideal for properties with spotty GPS coverage like mine. But it is less nimble than the other AWD models thanks to lower ground clearance and weaker suspension.

Its turning mechanism tore up a couple areas of my garden, particularly a shaded area near my neighbors’ sprinklers, which stayed damper than other spots. Mammotion has acknowledged this issue, saying it identified that a recent update to the turning logic caused some unwanted results. The mower turning too sharply might tear up the grass to some extent, especially when the ground is wet and slippery, or the grass is not very thick. They have deployed several software updates to address this, but we should all be wary of relying on software updates to fix fundamental problems with an expensive lawnmower.

A budget option for smaller yards with or without trees

Roborock RockNeo Q110H

The $1,299 Roborock RockNeo Q110H is my budget pick. This rear-wheel-drive mower was impressive on my flat, treed front yard, although its lack of all-wheel-drive meant that the occasional large tree root stopped it in its tracks. That, and its more limited range, is why it is half the price of other mowers here. It offers RTK and vSLAM navigation, with the option of antenna or NetRTK.

The RockNeo is remarkably similar to the Segway Navimow i100N I tested last year, with a few upgrades, including better camera-based obstacle detection, steeper slope navigation up to 45 percent, and a wider cutting blade. It can also be used for manual remote-control mowing and has a built-in edge-cutting feature, although there is the option of an edge-cutting add-on module that I have not tried.

Edge cutting is still very much a work in progress for all mowers. Some do well straddling the edge, but if you have a fence or delicate boundary, that will not work. Companies are trying all sorts of solutions, including special attachments. The Ecovacs Goat A3000 Pro Lidar looks to be the most promising, thanks to a side-mounted string trimmer. But for now, you should plan to keep your manual trimmer handy.

Robot mowers have improved significantly over the last 18 months. Advances in navigation have solved my main pain points from the last round of testing, and bigger, beefier bots are now better at navigating the varied terrain of American yards. Today, the right bot will maintain your yard beautifully with minimal effort. While they still need oversight and the occasional rescue, and they have not solved every problem, they do take a lot of the work out of maintaining your yard.

Source:The Verge News