Robot Mowers without a Perimeter Wire

This article covers the pros and cons of robot mowers that require a perimeter wire versus mowers that don’t.  If you are interested in GPS RTK mowers, also read our latest article.

Business For Sale

Earlier this year, I was diagnosed with prostate cancer but fortunately it was picked up and treated early and everything points towards a full recovery.

When I started The Robot Mower, it was meant to be a part-time “hobby” but it became too successful and turned into more of a full-time job so I’ve decided to sell the company so that I can concentrate on other things.  

I’ve spent over 4 years building the company so it would be a shame to see it disappear so if you are interested in a ‘ready made’ robot mower sales and installation company then get in touch.  The company would ideally suit someone in the East Anglia area and would come with all the necessary tools, equipment, a van, a loyal customer base and a website that attracts over 300 people a day.

Finally, if you are male & aged 50+, please make sure that you have regular PSA checks so that you can be as fortunate as me – prostate cancer is the most common cancer in men.  In the uk 144 men are diagnosed every day. Every 45 minutes one man dies from prostate cancer – that’s more than 12,000 men every year. 1 in 8 men will be diagnosed with prostate cancer in their lifetime. For more information see Prostate Cancer uk.

Ambrogio L60 robot mower on grass

No perimeter wire - is it new?

There are very few robot mowers available that do not use a perimeter wire and those that do, tend to be either for large open areas (Belrobotics RTK & Husqvarna EPOS mowers) or for small gardens with specific types of boundaries ( Ambrogio L60 & the new Ambrogio ZR). The only current solution that covers all sizes, layouts and complexities of normal domestic lawns are the wired mowers (see our wired range).

This started to change in 2022 as manufacturers have started to release (or promised to release) a number of new robot mowers.

As the manufacturers start their product announcements for 2023, some of the big manufacturers (Ambrogio's RTK mower & Husqvarna's Nero) have revealed products for 'normal' gardens.

The rise of the robot vacuum has raised peoples expectations of what a robot lawn mower should be able to do but the inside of a house is a much more controlled environment that your garden.

Deciding whether your mower should be wired or wireless is only one of the decisions you need to make to ensure you choose the right mower for you. Find out what other things you need to consider when choosing a robot lawn mower.

Self Installation Kit for Robot mowers

Why use a perimeter wire?

A robot lawn mower needs to pinpoint its position to within a couple of cms to ensure that it gets as close to the edge of your lawn as possible but doesn’t overshoot and end up in a flowerbed, pond etc. The perimeter wire/ guide wire is used by the mower to:

  • Identify the extent of where it can mow and where it can’t – a signal is sent by the base along the wire and picked up by the mower as it approaches it.
  • Allow it to navigate from the base to other areas/ zones…and back again - some mowers use 'guide' wires for this.

The benefits of a perimeter wire are;
  • Once it is laid, it defines the edge of the lawn and is not affected by external forces e.g. weather, visibility, tree cover etc.
  • If you change your garden, you can move the wire and you know that the border is redefined.
  • You are in control...if something goes wrong, it is easy to work out if it is the perimeter wire or the mower where the problem lies

You may think that installing a perimeter wire is difficult but we have a lot of customers that do it themselves, have a look at our installation videos.

Wire Laying Machine at L350 installation

What's the problem with a perimeter wire?

There are a few potential issues with having a perimeter wire but also mas it has been around for so long, these can be mitigated:

  1. Someone has to install it – this means extra time if you do it yourself, or extra cost if someone else does it.
  2. The perimeter wire can be damaged by animals or someone putting a spade through it - there are reinforced wire solutions available which greatly reduce the chance of a wire break.
  3. If you want to change the area to be mowed, it means re-laying the wire - but with gel filled connectors, it is easy to join new wire to an existing layout.

Robot vacuum cleaners don't need perimeter wire...but then they run in very controlled environments where most areas are bordered by walls.

Is 2022 the year?

Is 2022 the year?

Since robot mowers have been around for over 20 years, the issues with perimeter wires are not as major as they may seem but wouldn’t it be nice to just put a new mower down and have it work out for itself where the grass is?

A number of manufacturers have been working on this for years but 2022 has given us a first glimpse of the reality...I must emphasise 'first glimpse' as the likelihood is that robot mowers without a perimeter wire will never be able to cope with all situations and hence perimeter/ guide wires will always have their place and it is likely that it will be a couple of years before the wireless mowers catch up with their flexibility of their wired cousins .

Robot Mower Technology

Different approaches

If you look at the products available/ announced, there are 2 fundamentally different approaches to solving the problem:

  1. Technology allowing the mower to identify its exact position
  2. Technology allowing the mower to identify grass (or lack of it) and other obstacles

You can also have a mixture of both!

Pin Point positioning (RTK)

Pin-point positioning

People often ask us why our robot mowers need a perimeter wire if they have GPS. The answer is simple, GPS is not accurate enough, we need position accuracy to within a couple of cms, with standard GPS, the accuracy is at best 70cms but normally a meter or two, at worst it could be impossible to get a position if you can't detect 3 satellites.

This problem is not new and although the military uses enhanced GPS, experts have been working on another solution... Real-time kinematic positioning (or RTK as it is commonly known).

Read the Wiki for the details but to put it simply, as well as the GPS signal from the satellites your mower receives, you use the an additional GPS receiver (sometimes attached to the base) which transmits correction info to the mower to allow it to have pin-point positioning.

The theory is great, and you can see it in action on large open spaces (football pitches, golf courses etc. but the question is how well it will work in a "normal" uk garden. The problem is that both receivers (i.e. mower and additional receiver) need to have power, a good satellite signal and a good connection between them. Things which can affect the satellite signal are:

  • The proximity of buildings/ walls, fences etc. (as the signal can bounce off them).
  • The lack of a clear line of sight of the satellite which can be obscured by trees or even affected bad weather (similar to what happens to a sky satellite signal).

Similar approaches to GPS RTK are to use beacons which are placed around the lawn. The mower receives a signal from the beacons and uses those (rather than the GPS satellites) to identify its position relative to the beacons. There has also been some work on using the mobile phone network/ masts, which in effect act like beacons.

Whether you are using RTK or beacons, the mower needs then needs to be 'taught' where it is meant to mow, this can either be done by 'driving' the mower around the perimeter or mapping the perimeter on a satellite image (again another source of potential problems/ errors).

grass indentification

Grass/ object identification

Because of the problems obtaining pin-point positioning, other manufacturers have been looking at enabling a mower to identify grass and other objects so that it cuts the grass and knows where the lawn stops. In some ways, grass/ object identification is a similar approach to that taken by a robot vacuum cleaner.

Radar or cameras use mounted on the mower and the inbuilt Artificial Intelligence (AI) in the mower is used to match what the mower 'sees' against what it knows is grass and other obstacles.

In theory this approach should work well as it does not rely on external sources (GPS/ beacons) but the problem is that there are so many different types of grasses that it needs to recognise. Fortunately what one mower learns can be 'taught' to other mowers.

Other objects which are useful to identify are:

  • Raised borders/ fences etc.
  • People, animals etc.
  • Dog poo - a frequent question we are asked about the current mowers!
  • Intruders - some manufacturers have also put some thought into using the mowers to be a mobile security camera at night.

Using cameras is not new as all of the big brands (Ambrogio, Husqvarna, Robomow) have tried this approach but have not taken it to market as they were unable to solve the problems that the weather, direct sunlight (or lack of light) and dirt posed to cameras. This is why they started looking at Radar or GPS RTK.

grass identification vs positioning

Positioning vs object identification vs perimeter wire

So which approach is likely to give the best results?

There are pros and cons of each approach, but whatever the approach, it must cope in the real world which is not the controlled environment that you see on a lot of promotional videos (or animations as there is no product currently available).

The key thing to remember is that you are buying a robot lawn mower that doesn't use a perimeter wire, they still need to get the fundamentals of a robot mower (cut quality/ reliability etc.) right first and then add the ability to not have a perimeter wire afterwards. See our article on choosing the best robot mower for you.

A summary of mowers available/ planned

L60 mowing on walled garden

L60 by Ambrogio

The L60 has been around for a number of years and uses 3 sensor to identify the edge of the grass: Bump sensor - to identify raised edges Grass sensor - to identify when it moves outside of a grass area Drop sensor - to identify when the grass ends and a lower flower bed starts.
The latest version (the L60 S+ extends its range to 400 m2. Although not as high tech as some of the newer models, it has proved very popular with people who want to 'drop & go'.

Ambrogio Twenty ZR

Twenty ZR by Ambrogio

Ambrogio have been making robot lawn mowers for over 20 years so should know a thing or two about them.

Although most of the Ambrogio range has GPS fitted, they have gone down the route of grass identification to remove the perimeter wire.

The Twenty ZR builds on the very successful Twenty range and adds Radar and AI for grass detection and for identifying other obstacles.

Coverage is up to 1000 sq.m. and at a price which is not much more than the Twenty Elite, it will definitely be popular. The mowers started arriving in the uk in mid 2022 but in very limited numbers. We are promised a good supply in 2023 so make sure you put your name down for one if you want one.

If you really wanted an RTK machine then don't worry, Ambrogio just announced that they will start production of RTK models in 2023 (a 4.36 with coverage up to 10,000 sq.m.) - more details soon!

Terra T7 by iRobot

iRobot are best known for their robot vacuum cleaners and so should know a thing or two about robots.  Unfortunately, this robot was meant to hit the market in 2019 but we are still waiting. 

This uses beacons set around the perimeter of the lawn.  The beacons will have to be installed by an approved installer and may not sense smaller objects, so clear your yard of small obstacles like toys, equipment, or gardening supplies before any scheduled or on-demand mowing jobs (an extract from their manual).

Segway Navimow robot mower

Navimow by Segway

Navimow is brought to us by Segway-Ninebot, again you would think they know a thing or two about positioning...but not necessarily about robot mowers.  The Segway name is best known for their self-balancing transporter but you may be disappointed to find out that Ninebot bought Segway and have stopped making the iconic transporter.

The Navimow uses what they have called Exact Fusion Locating System (EFLS) which seems to be RTK  plus extra sensors.   We have heard some good reports about this machine although the early test versions had some issues.  They do say that you need to place the base station more than 2m away from buildings or fences and the base must have wi-fi coverage. They have now added a checklist to see if your garden meets their criteria. The key things seem to be tall trees/ building/ fences in or around the garden which is not surprising.

They have started delivering in Europe (as of end June 22), the feedback seems to be mixed but a number of people have reported issues with the software (which may be solved over time) and a few hardware issues (which may be more difficult to resolve easily).

For the latest info, check out their facebook page.

Novabot by LF Intelligence

Novabot comes from LF Intelligence whose core team were academically trained at the University of Pennsylvania.  

This was a crowfunded project (see the Novabot VIP Global Launch Group facebook page) and were worried by some of the claims that are being made in response to questions people have raised….if it will do everything they are claiming then they will have a world-beating product, but we would recommend not buying one until you can see a production model working on a real lawn.

In response to questions, they have said that this machine has an HD panoramic camera, a millimeter radar sensor and uses RTK!

They will be offering 2 models, a 1000 sq.m & a 2000 sq.m. model with delivery originally promised for July 2022 but they have just started shipping test models (Nov. 2022).

EPOS/ NERA by Husqvarna

Husqvarna is one of the largest robot lawn mower manufacturers and knows lots about robot mowers.  They announced EPOS (Exact Positioning Operating System) a couple of years ago and have the system working on some large open spaces.  This is an RTK solution and was aimed at commercial situations (open football pitches etc.).

They have just announced (Oct 2022) a new lawn mower (NERA)  that will be aimed at private gardens based on the EPOS system.  It will be launched in 2023 and cater for areas from 2200 to 5000 sq.m. but we will have to wait for prices.

Willow by Eeve

Formally called Toadi.

It is difficult to get much information about Willow but it is a strange looking machine which you would image has too high a centre of gravity but it is certainly different.

It uses an HD camera, it is 3D printed and that’s about all we know.  There have been reports of people sending them back as they ended up in ponds & crossing driveways.  After a couple of years, it still seems to be in the beta stage so one to look for in the future.

Despite there being little information, they have just started producing some TechTalk videos.  These make very interesting watching as they seem to be very honest about the issues that they have encountered and some of those issues are likely to be encountered by other manufacturers.   

Their delivery date has been pushed back from June 22 to January 2023 due to component shortages…a common problem across the whole industry.

Eeve Willow
Play Video about Toadi Willow

GPS-RTK by Belrobotics

Belrobotics have been making robot mowers for a while concentrating on larger lawns (10,000 sq.m. +).

Last year they announced GPS-RTK which can be added to their current mowers so that they won’t need a perimeter wire.

The addition of GPS-RTK can increase their coverage almost fourfold by mowing in a pattern i.e. parallel ‘stripes’ rather than a more random approach taken with other mowers – don’t get excited, as there is no mower it won’t leave a stripe in the grass. You can also mix areas i.e. have one area with a wire/ random cutting and another with no wire/ pattern cutting.

Again, it will be interesting to see how this works on ‘back gardens’ but if you have a very large lawn, this is definitely one to look at.  Contact Us for more details.


Crowdfunding has started for a New Zealand based mower called Conga.  

This looks quite ‘retro’ compared to some of the newer models but uses cameras to augment the RTK system so may prove to solve some of the problems that you encounter when trying to use RTK in a garden with fences, tree, building etc.

Goat G1 by Ecovacs

The Chinese robot vacuum cleaner manufacturer Ecovacs has just announced their first robot lawn mower. 

This will not use RTK as they consider it  to be not accurate enough and not reliable in gardens that have obstacles that may obstruct the GPS signal.  They have decided to use a mixture of GPS, on-board cameras and ultra wideband (UWB) technology to ensure it has pinpoint accuracy.  The UWB technology requires an extra antennae to be placed at the edge of the garden (similar to the Terra T7?).

Details are limited but they have a polished video for the announcement.  It will be interesting to see how this progresses.

ardumower robot mower


If you prefer to build something yourself, it is worth looking at the ArduMower.

You can buy the mower as a kit, customise it and add a GPS RTK board to it.  All the bit are available from the Ardu Mower shop.

We haven't been able to find any decent videos of it working but there is a wiki and a forum with loads of information.

Although this is really for the enthusiast who likes building things, the shop also list Alfred which looks like a fully built solution.


Luba by Mammotion

Recently announced as a kickstarter project is Luba .

This will be a 4 wheeled drive mower that can handle up to a 75% gradient similar to the Ambrogio QUAD

Details are still limited but remember that with any kickstarter project if you 'invest' money in it you may receive a mower at the end of the day or not (with no refund).

Give us your feedback

We intend to update the above as more details become available so if you have some first hand experience of the above, or have any other mowers which you think should be added, please get in touch.

41 Responses

    1. Hi Hugh,
      If you look at the Wiper mowers, you will see that they are exactly the same as the Ambrogio mowers but a different colour…just rebadged.

  1. Gps-RTK has the same issue as standard GPS. The signal is blocked by buildings and trees. If it needs 20 degrees line of sight to the satellite, it is not a solution. Novabot uses humidity sensors, same as Ambrogio. Zucchetti (Ambrogio manufacturer) has a patent on a robot mower with humidity sensors so Novabot will likely get shut down.

    1. Agreed regarding GPS-RTK. In the uk, Husqvarna & Belrobotics both offer the systems but from what I hear have only been installed into large open areas where the line of sight is not a problem. Most of the marketing info fails to point out that both the mower and the additional receiver need line of sight which is normally not possible in domestic settings where there are trees, buildings etc.
      It’ll be interesting to see how the planned models which will offer GPS-RTK in conjunction with a backup where line of sight fails e.g. a camera work out.
      For a normal domestic setting then it looks like the perimeter wire is here to stay for the foreseeable future unless an Ambrogio L60 or ZR meets the needs.

  2. I have found a little bit on SmartMow by FutureGenRobotics. It looks promising and interesting, but I have not found a lot about them.

    1. Interesting. Looking at their website, the last blog post was in 2019 and their crowdfunding has raised less than $9k out of a max $1m so I don’t think that they are likely to bring anything to market soon, but you never know…good spot.

      1. The thing that got me was their crowfunding got very little and novabots was insane. Smartmow has a little bit on Twitter too and had an issue with some of novabots marketing materials. I think Smartmows product looks appealing as I have a large yard but these ‘toys’ are expensive.

  3. Where are the price’s ?
    Can they move to other lawns as we have separate ones.
    Belrobotic’s looks a good one.
    I want one that does not need a wire boundary.

    1. Hi Michael,

      The blog just covers all the mowers coming to the market, we only sell Ambrogio & Belrobotics…you can find the prices on the model pages.

  4. Anyone know anything about the Mammotion Luba RTK mower? Has launched on Kickstarter.

    I have a large and complex garden (multiple paths, trees, hedges and driveway). I am in the market for a robot mower as it costs a fortune to keep the grass down, but I would need so much wire it doesn’t seem worth it. What would people recommend?

    1. Hi Jasper, looks interesting. I assume it is using the same opensource software that can be seen on other projects. I did look at the videos on kickstarter and you can see that both areas are completely free from trees, buildings etc. that may affect the GPS signal and they are using a large antenna. How well it will work in a ‘normal’ garden i.e. with trees, a house, fences where there may not be a clear line of sight to 3 GPS satellites will be interesting. Also it is 20kg which is quite a weight.

    2. I paid for one of these at the beginning of May and was promised a 15 to 20 day delivery. Still waiting and they are still obfuscating and refusing to give me an actual delivery date so I have given up and asked paypal for a refund.

    3. I have one. Its not a bad unit, but as others have stated, it needs a direct line of sight with the satellites and the signals bounce off the walls of my home and neighbors home rendering the tool useless. I wish it was better at mowing too. I lose POS many times a mow, which means, I have to go outside and correct it. A 20 minute job in Mammotions time = 1 1/2 hour due to being stuck or simple transitions from cement pavement to grass. Stinks really, I wish it would have done better with its 4 wheel (or 6 wheel) drive. I wish it had a sense of AI that would find obstacles in its way and MAP them to the layout. This could have made it better. I hear most of the buyers here have remorse. I paid 2400 for my model and waited a month to get it. (unlike the pre-kickstart folks who got theirs 1/2 off). All in all, if you have an OPEN field of grass and are in a clear line of sight, its a good tool. but for now, till I can find a system that is no-wire and can navigate obstacles and remember my markers, I will have to go at it manually, heck I get it done faster myself manually anyway.. lol..

    1. hi re Conga mowers. i live close to christchurch. I keep my finger on the pulse so to speak, i have never heard of Conga till reading this page which surprised me. I drive down Sheffield crescent every few weeks. they don’t list a street number which is very unusual. The phone # is not a Christchurch phone number which start with a 3…. The phone number does not work when you ring it and the email address is wrong and as expected bounced back.

      The English used is not gramatically correct. I think this site is fake. cheers Warren

  5. There’s also Kress

    Also for sake of completeness it should be mentioned that it is possible to use ArduPilot (ArduRover) to convert traditional lawn mower (or any other) to robotic lawn mower with RTK. It is DYI project and there’s number of people who had done that before.

  6. Wondering if there is a robot mower with a combination of perimeter wire around the lawn and then short range non-wire so that there is more flexibility on where the charging station can be placed e.g on a patio next to a electric point or tucked away so it is not so obvious.

    1. HI Steve, I’m not aware of any but the charging station can be placed off the lawn, you just need to look at the installation instructions for each mower. Some mowers have a guide wire which can help with the base placement.

  7. Thank you for this very illuminating article. I have now held off on my plans for a robot mower purchase, to wait and see where the wireless market goes this year. I was leaning towards a Worx robot, because of the cut to edge feature. Do we know how close to the lawn edge all these mowers get? I’d like to avoid going around trimming all the edges, if possible

  8. Can you do an update on this article. It’s great! Also there is now Heisenberg Robotics wire free mower. Seems to be AI & cameras?

  9. Forget the Ardumower. I bought one, discovered it was simply a bunch of parts. Now it did say it was a kit but I didn’t expect I’d have to solder every single electronic part with no reliable English directions and what directions there are are for multiple versions. HUGE mess. I finally asked to return -at my own expense – and they said sure, we’ll refund your money. Still waiting for it, and paid $400 to ship it back to them. So I have NOTHING for almost a $3K investment. Don’t repeat my mistake.

  10. I was going to buy the Lawnmaster vbrm16 but cant find any stock. i am 83 and the lawn is small so any advice on what to get if lawnmaster no longer available would be appreciated

    1. The closest that we supply is an Ambrogio L60 S+ but it does a much larger area (400 sq.m.) and costs quite a bit more.

  11. Great article. Thank you.

    I was poised to buy the LUBA but I now realise it wouldn’t be able to see its RTK base station when mowing those areas where the house will block the signal. Yes. You are correct. I hadn’t spotted all the YouTube videos show open grass areas. Shame. I loved the straight lines.

    So … thank you to everyone contributing to this article. You saved me U.K. £3,000

  12. Hi all, I am on a lifestyle block in NZ with House lawn 6900m2, other lawns of about 4000m2. Bought a Husqvarna 450X to do 5000m2. Had water issues from puddles, couldn’t cope with spring growth and Kikuyu, had to replace spinner bearings 4 x in 12 mths, countless blade entanglement with fibrous leaves, etc. Taken out of service and they would not refund. Then bought Ambrogio L250S+ and L350 elite. My favourite is the L250S+ which leaves Husqy for dead. Handles flax and fibrous leaves, great in the wet, blade lasts 18 mths but admittedly has lost 1 cm in diameter but never had to resharpen. Then bought a LUBA for a remaining cottage lawn. Had it 3 weeks now. Great to install however not good in the wet or on wet slopes. It has dug up a bit of lawn even with the fancy new front wheel system. Also in the wet becomes clogged up. A friend also has one and on a bigger lawn he had to clear it five times in one day. NZ has had a lot of rain and often heavy dew in the mornings so that is a challenge for the LUBA. Also stopped for some unknown reason doing the roadside and overnight on the roadside!!! Luckily it was still there in the morning with no anti theft. I now spend more time watching the mowers than I did mowing the lawns according to my wife!!

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