But, is that a good thing?
Let's look at a few of the options available to manufactures using today's technology.
Robot Mower with Sensors
Mowers like the LawnBott Spyder, for example, don't use a perimeter wire. In fact, according to the LawnBotts web site, this is hailed as "a new beginning for robotic lawnmowers."
However, I would dispute this, as I have a friend with a sensor-based mower that pre-dates my own Husqvarna/Gardena R40Li, which he inherited from a family member who I assume had upgraded to a better version.
A quick question and answer session later revealed that while there are issues with sensor based mowers, largely my friend was well satisfied with the performance of the mower. However, there were a few basic flaws.
The first is that without a ground wire, the mower has to way to find it's way "home" for recharging. Therefore, it has to be charged indoors.
In fact, the mower has no way of knowing where it is, or where it has been; it's a dumb mechanical device, with none of the intelligence built into more modern models.
The way that they work is simple: they have sensors facing down which detect grass, and bump sensors to prevent chopping up the family pet. The lawn sensors rely on moisture detection, and the ability to tell the difference between mildly damp grass and, say, concrete or gravel.
My own feeling is that this is fine for most regularly shaped, enclosed areas, but as soon as you add a pond, or something that can become overgrown and poses a threat to the mower -- either damaging it, or allowing it to 'escape' -- I wouldn't feel personally comfortable relying on a few sensors to keep it in check.
Then there's the security aspect: one can imagine that stealing a plug-in to recharge mower that doesn't rely on a coded perimeter wire signal is a bit more of an attractive option than one which relies on a fully wired-in installation.
However, there are other options.
Robot Mower with a Virtual Perimeter Wire
These fall into two categories:
- Roomba style transmitters;
- Remote control / smartphone control plus learning.
In 2015, iRobot secured the go-ahead from the FCC to develop and deploy the same kind of technology that is used for their Roomba robot vacuum cleaners for outside use. This would allow them to create an iRobot lawnmower. Because it is guided by localised positioning using radio waves, however, it sparked anger amongst radio astronomers.
Of course, since then, their flagship technology has moved up a gear, and now uses all kinds of visual cues and smartphone interaction to "map and adapt" to the task in hand, rather than using navigation pods. Perhaps this move away from the older technology explains why we haven't seen the iRobot lawnmower as yet.
That leaves remote control or smartphone control plus learning. In fact, SmartMow has pinned their hopes on this approach, and have patented "Virtual Boundary Technology" which they explain as the ability to "Just walk SmartMow around the perimeter of your yard".
I'm actually looking forward to reviewing the SmartMow, because it appeals to me on a number of levels, including some exciting technology for connecting to it via a web portal.
The idea seems to be that the mower will learn where the perimeter is by being "shown" it, and then left to its own devices. Of course, the mower also has the regular sensors to allow it to avoid unexpected objects, but because the solution is software rather than hardware, my reservations re: ponds and robots going mad (as in the movie Short Circuit) still hold.
Robot Mower with GPS
Everything from farm machinery to those massive machines that rake the pistes in the Alps use GPS, so why not home robot mowers?
Husqvarna's Automower does just that. It even has its own app to help you fully take advantage of the set and forget nature of automatic robot lawn mowing.
(By the way, these are at the expensive end of Husqvarna's range -- the affordable models still use a perimeter wire... as do the ones with GPS!)
But here's the thing; it still uses a guide wire, presumably for security reasons.
In fact, aside from this experimental design from 2016, I was unable to find an example of a commercial automatic lawn mower that relied 100% on GPS for its perimeter detection and mowing capability.
So, all in all, it seems as if the good old perimeter wire is here to stay: sometimes lo-tech is really the best tech! If you're still wavering, read our Perimeter Wire Tips & Tricks Post; I'm pretty sure you'll agree that it's still the easiest, safest and most reliable method of keeping your robotic mower in check.
