How Do Robotic Mowers Work

How Do Robotic Mowers Work?

How Do Robotic Mowers Work

As a gardening enthusiast, I’ve always been fascinated by the advent of robotic mowers and how they’ve revolutionised lawn maintenance. Essentially, these ingenious devices operate autonomously, navigating through gardens and cutting grass with precision. They use a combination of sensors, GPS, cameras and boundary wires to ensure they stay within the designated area. The onboard computer systems enable them to detect obstacles, avoid them, and manage varying lawn complexities. What truly impresses me is their ability to return to their charging stations when their batteries run low, ensuring they’re always ready for their next mowing session.

Here’s a concise list explaining the workings of robotic mowers:

  • Navigation: Uses boundary wires, GPS (including RTK systems), and camera guidance to navigate and map the area accurately.
  • Sensors: Equipped with collision, lift, tilt, and rain sensors to operate safely and respond to environmental changes.
  • Cutting Mechanism: Features small, razor-like blades on a rotating disc for consistent and precise grass cutting.
  • Battery-Powered: Runs on rechargeable batteries and autonomously returns to its charging dock when power is low.
  • Programming: Allows for the setting of mowing schedules and specific lawn management preferences.
  • Obstacle Detection: Employs onboard sensors to detect and avoid obstacles, ensuring uninterrupted operation.
  • GPS and Mapping: Some models utilise GPS to create a detailed map of the garden, which helps in optimising mowing paths.

How Do Robot Lawn Mowers Navigate?

The beauty of a robotic lawn mower is that it will cover the entire lawn without you having to lift a finger. Most robotic lawn mowers mow in a random pattern and the great thing about this is that there won’t be any track marks left on the lawn which can be unsightly.

How Do Robotic Mower Work In Terms Of Navigation?

The way this random mowing system works is that the robot will mow in a straight line up until the point that it detects the boundary wire or an obstacle. When it does, it then turns around and mows in another direction. Over the course of the mowing time, it will eventually cut all parts of the grass. It’s also worth noting that a robot lawn mower isn’t designed to mow the whole lawn in one sitting, once a week like a walk behind. Instead, it will go over the grass on a daily basis, taking off little and often.

Higher end sophisticated models are even more intelligent and understand the size, shape and type of your lawn. They know what areas they have already cut making them more efficient and effective at keeping the whole lawn looking neat and tidy. Some models will allow you to add optional sensors that enable the robotic mower to “see” obstacles before actually bumping into them. Most models will allow you to zone the lawn, so you can focus the mower on areas where the growth is greater or according to your requirements.

Most robotic mowers will also allow you to schedule the edge of the lawn to be cut, so the mower will navigate around the perimeter wire trimming the edge of your lawn.

So, How Do The Blades Work?

How Do The Blades Work on robotic mowers

Compared to larger walk behind lawn mowers, robotic mowers have much smaller blades. Plus, they move much less quickly so they will take longer to cut the same amount of grass than your regular lawn mower.

When purchasing a robotic lawn mower, you will have two considerations when it comes to the blades.

Rotating discs have several rotating razor blades which are much smaller. In many cases, they’re no bigger than a razor blade but they’re still very effective at cutting the grass. You will find that robot mowers with this type of blade system have a much smaller cutting diameter than other types, but they also operate much more quietly.

There are also robotic lawn mowers that come with a solid cutting blade. You can get single blades or mowers that have several blades which improves the size of the cutting width. While these are typically more noisy than rotating blades, they are much more powerful. You’ll find that these mowers are powered by larger batteries and are designed for larger lawns.

In summary, for the average domestic UK lawn the smaller rotating razor blades are going to be your preferred method, as they provide a clean and sharp cut, are cost effective and easy to replace.

How Do Robot Mowers Collect The Clippings?

All robot lawn mowers work using a mulching function. The great thing about this is that it hugely benefits your soil. This is because the clippings are packed with nutrients that feed the lawn and make it healthier, greener and more lush.

What’s more, mulching is far more convenient on a robotic lawn mower. Could you imagine a compact robot mower with a huge grass collection box on the back? It would require more power to move it around and would mean you having to manually empty it which goes against the concept of having a robot mow your lawn.

In summary, robotic mowers do not collect the grass clippings and for a good reason as mulching is highly beneficial to the health and appearance of your lawn. What’s more once installed there is nothing for you to do apart from relaxing and enjoying your garden.

How Does A Robot Lawn Mower Know Where To Mow?

How Does A Robot Lawn Mower Know Where To Mow

There are some robotic mowers that can be programmed to move around the lawn without any assistance. But these are some of the newest and most advanced models on the market. For the majority of robot lawn mowers, a perimeter wire is required.

This wire comes with your robot lawn mower and you install it around the edges of the lawn/s you wish to be mowed. You have the option to lay the wire on the ground or bury it a few centimetres down. Either way, the robot is programmed, using its on board computer, not to go past this wire. I have found that by laying the wire on top of the lawn (pulled firmly), within a couple of months the wire will bury itself, saving you time and effort, whilst remaining effective.

The perimeter wire is connected to your robot mower’s charging station. This means that, not only is the mower able to detect the boundary but it can also navigate its own way to the charging station for re-charging.

What About Any Obstacles In The Garden?

What About Any Obstacles In The Garden?

One of the main concerns for people considering purchasing a robotic lawn mower is that it will collide with obstacles in the garden. Moreover, if you have children and pets, there is a worry that the robot will plough into them, causing injuries.

However, the great news is that robot mowers are intelligent in more ways than one. They are fitted with sensors that prevent them from colliding with anything that is on the lawn. That said, most of them are not so advanced as to detect an obstacle right off the bat. You’ll usually find that they gently bump into the obstacle once, and automatically turn off the blades for safety. After this, the mower will then turn around and mow in a different direction.

In the case of smaller obstacles, you may find that the mower is able to simply drive over the top. While this might be good in some circumstances, you need to be careful if you leave small flat objects on your lawn. That said, if it is a permanent object then you can use your perimeter wire to cordon off these areas to ensure the mower avoids them. If the robotic mower is raised from the lawn either through being picked up or hitting an object that raises the front of the mower, the lift sensor will automatically stop the blades from turning.

In summary, robotic mowers with their safety features are safe, if not safer, compared to any other type of lawn mower.

How Robotic Mowers Work In Terms Of Power

How Robotic Mowers Work In Terms Of Power

All robot lawn mowers are battery powered. It’s as simple as that. OK, there might be a little more to it. You’ll find that almost every model today runs on a lithium-ion battery which typically gives you around half an hour of mowing time per charge.

But once you start paying more for your robot mower, this running time will increase owing to a more powerful battery. In short, the higher the voltage and Ah, the more powerful and longer running the battery will be. In some cases, the best robot lawn mowers will run for around four hours without needing to recharge.

Another great thing about lithium-ion batteries is that they tend to charge more quickly, so your robot mower won’t be out of action for as long. When the power runs down, these intelligent machines will return automatically to their charging station to reboot that juice.

You should keep in mind that your robot mower itself will likely last longer than its batteries. But since most models feature a removable battery, you can easily replace these. Depending on the battery and how often the mower is used, you’ll normally only need to replace it around once every three to five years.

In summary, you really do not need to worry about the run and charge time of your robotic mower’s battery as once installed you simply forget about it and let it do its thing (and it does it well). Just be sure to purchase a robotic mower that is designed for your size of lawn.

I’m Worried About Security – How Does That Work?

Robotic Mowers Security

Most newbies in the robotic mower field worry that leaving a robotic lawn mower outside unsupervised could result in theft. And this is a viable concern. However, you will find that almost all robotic lawn mowers are kitted out with some kind of security system.

The most common on modern models is a PIN code. This needs to be entered in order for the mower to work. Most thieves would be aware of the need for a PIN and so this can act as a deterrent.

There are also some robot lawn mowers that have GPS tracking. You’ll usually connect your mower to a compatible smartphone app which allows you to do everything from setting a mowing schedule to monitoring security. In the event that the robotic mower is taken or lifted, you will be alerted via the app and even be able to track it if fitted with a GPS module. Husqvarna were the pioneers where robotic mowers were concerned and they’re still at the head of the game in terms of security, so you’ll often find their products have these GPS systems.

Finally, most robotic lawn mowers are fitted with an alarm. This alarm will sound in the event that the mower is moved out of the mowing zone. Some have sensors that cause the alarm to sound when the mower is lifted or even tilted off the ground. Again, alerting the app immediately if it has this capability and is installed.

Other Features Of Robotic Lawn Mowers

The things I have discussed so far are among the most common features of robot lawn mowers and will help you to better understand how they work. But depending on the model you purchase, you will find it comes with a number of other features. Let’s take a brief look at some of these.


If you have a particularly hilly or sloped garden, then some robot lawn mowers won’t be able to handle these inclines. It is therefore important to look for models that have a higher slope capability. This is typically given in percentage and tells you the degree of incline the mower can navigate.

Weather Detection

Robotic Mowers Weather Detection

The UK is hardly reliable when it comes to the weather, and we experience a lot of annual rainfall. As many of you will be aware, it is never a good idea to cut your lawn when it is wet so it’s essential that your robotic lawn mower doesn’t mow unless the conditions are suitable.

Most, but not all robotic mowers are fitted with a rain sensor. This tells the mower that the conditions are no longer ideal for mowing and it will automatically return to its charging station until conditions improve.

Multi Zonal Mowers

If you have more than one lawn, or a lawn that is separated by something like a path, then your robot mower won’t be able to navigate this without a multi zonal function. This works by running the perimeter wire from one zone to another allowing the mower to move between the two.

With that in mind, there are some robot mowers that will need to be manually moved between lawns. This is particularly true if there is no way for the mower to navigate itself between the lawn i.e. steps, wall, gates.


Robot mowers are the future of lawn mowing especially for people who don’t want to, or don’t have time to maintain their lawns and still want them to look amazing at all times. These innovative devices have an intelligent on-board computer that controls where they mow, when they mow and when they charge.

Understanding a robot lawn mower isn’t too complex once you wrap your head around the technology. As with many smart devices these days, robot mowers are usually compatible with a smartphone app which allows you to remotely control them for convenience.

If you’ve been considering getting a robot mower but are worried that the tech will be too advanced, there’s no need to be concerned. While these are the height of technological advancements, they’re designed for user friendliness so even if you’ve never used a robot mower before, you’ll find it super easy to install and use. Furthermore, manufacturers have produced robotic mower that are “plug and go”, there is no app no on-board display, you simply install the perimeter wire and press “go”. These are designed for less tech savvy people who like things uncomplicated but still want to benefit from all the advantages a robotic mower has to offer.


Looking for more Best Robotic Lawn Mower Reviews? – Best Robotic Lawn Mower


Lawnmower Product Expert, Reviewer and Author at | 01284 615144 | | Website | + posts

As a seasoned expert in the field of garden power tools, I have dedicated over a decade to working with and reviewing a wide variety of lawn mowers. My extensive experience has allowed me to gain a deep understanding of the benefits and limitations of different types of mowers and garden tools.

Over the years, I have honed my skills in writing informative articles and creating helpful videos for various blogs and publications. This has given me the ability to not only recognise what makes a good lawn mower, but also to help you choose the perfect garden tool for your specific needs and requirements.

With my wealth of knowledge and expertise, I am confident that I can provide you with valuable insights and recommendations when it comes to selecting the right lawn mower for your lawn. So, whether you're looking for a battery cordless, electric, petrol, or robotic mower, you can trust in my expertise to guide you towards the best option for your garden. Protection Status

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