How Do Robot Lawnmowers Work?
You've probably seen one buzzing around someone's front lawn while driving through a new neighbourhood but weren't exactly sure what you saw, a remote control car, maybe?
Well, sort of...
We've become accustomed to seeing robot vacuums in the household, but it hasn't been until recently that robotic lawnmowers were considered "worth it".
So, how do robot lawnmowers work?
Let's take a look...
Well, that time has come, and the robot mowers of today are equipped with some very advanced technology.
GPS, wifi connectivity, full mobile app control and intelligent mapping are to list a few features that these modern mowers are packed with.
If you're sick of spending your weekends slaving away behind a lawnmower when you'd much prefer to be watching the footy or sitting around the pool, then you should definitely continue reading...
What Are Robot Lawnmowers?
A robotic lawnmower is a small battery-powered device that mows your lawn automatically.
Modern robot mowers connect directly to your home's wifi and can be completely controlled with your smartphone.
Robotic lawnmowers are generally powered by a battery that charges when connected to the docking station.
Once the battery needs charging, the mower will automatically find its way back to the docking station to recharge and continue mowing.
As most robot mowers connect to your wifi, you can configure cutting times, monitor mowing progress and even send your little lawnbot out for a quick mow before a special occasion at your home.
Imagine being able to mow your lawn while you're in another country on vacation?
You can see why robot mowers are becoming more and more popular...
The Pros & Cons of Robot Lawnmowers
As with every new technology, robot mowers do have a few drawbacks.
However, technology is advancing at a rapid rate, and these drawbacks are starting to wither.
Pros
•They Save Time
The most obvious benefit of a robotic lawnmower is that it saves you time.
When you invest in an automatic lawnmower, you no longer have to mow on weekends instead of spending time with the family or catching up with friends, and you no longer have to mow after a busy day at work.
•Eco-Friendly
The battery-operated device uses less energy to recharge, greatly reduces carbon monoxide and nitrogen oxide pollution.
Small engines such as lawnmowers contribute over 6% of the total carbon pollution caused by humans in Australia.
•Your Lawn is Always Mowed
Unlike regular mowing, where you might mow every 1-2 weeks depending on the season or whenever your lawn starts to get untidy, robotic mowers mow much more frequently, often operating every day or every second day depending on the size of your lawn.
This means your lawn never gets long or out of control and always looks great with a fresh cut.
•No Noise
Sick of your neighbour inconveniently mowing his lawn at 7 am every Sunday while you're trying to get some well-deserved beauty sleep?
It might be time to convince them to get a robotic mower!
Robot mowers operating noise usually sits at around 60db, while most petrol mowers can reach as high as 110db!
Robotic mowers are much less noisy and can barely be heard in the background.
•Remote Mowing
Imagine sitting on the beautiful sandy beaches of Bali or the Maldives while mowing your lawn?
It's possible!
Modern robot mowers connect directly to your home's wifi, allowing you to schedule mowing times, monitor your robot and mow your lawn with a single tap on your smartphone!
Cons
•Setup
Most robot mowers on the market require a boundary guideline.
This is a wire placed along the boundary of your lawn that helps the mower identify mowing areas.
Setup can take anywhere between 2-6 hours, depending on the size of your lawn.
Some manufacturers and retailers will offer a professional set-up at an extra fee if you'd prefer it done professionally.
However, setup is a fairly easy process.
•Trimming Edges
Most robot mowers can get very close to the edges of your lawn, but just lawn your regular lawnmower.
There are certain areas that their little bodies can't get to. You'll still need to trim the edges from time to time.
•They Aren't For All Lawns
If your lawn is full of mounds, hills, holes and mud, a robot mower may not be your best option. Although some models such as the Husqvarna Automower 435x are designed for rough terrain, you'll be paying upwards of $5000 for this robot mower instead of the average price of $1000 $2000.
How do Robot Lawnmowers Work?
Robotic lawnmowers have electric motors that generally run on rechargeable lithium-ion batteries.
The user programs mowing times into the mower with a mobile app or the onboard control panel.
The mowing will then run according to this schedule returning to the charging station as it gets low on battery.
Once fully recharged, the robot mower will head back out and start mowing until it reaches the time the user has scheduled.
Robot mowers use a combination of bump sensors, guidewire and navigation systems to navigate and mow your lawn effectively.
It will usually take around 6-8 hours of mowing time for the mower to cover all areas of your garden.
Most robotic mowers travel in a straight line until they hit something, then turn around and head in a different direction, eventually covering the entire lawn before returning to their charging station when their batteries run out.
A robotic mower will mow your lawn more frequently, trimming less off the top.
By doing this, your lawn can use the small clippings and mulch and actually help your lawn get more healthy than it would by trimming huge amounts off every week or two.
Modern lawn mowers are also protected against theft with PIN codes and alarm systems that are triggered.
More advanced models even have a geofence. If used outside of a specified GPS range, an alarm will sound continuously, and the machine will lock.
The mower will send tracking data to the user via a mobile app.
Many models of robot mowers are also weather-proof, which allow them to operate 24/7.
Some robotic mowers will use a pinball-style mowing configuration.
They simply mow until they get to the guidewire, then re-adjust and continue until it's covered your whole lawn.
As robotic lawnmower technology is advancing, many manufacturers have realised that there are far more efficient ways for your robot mower to cut your lawn than pinball-style mowing. For example:
•The Husqvarna Automower uses GPS to create a map of your lawn and guidewire, remembering where it's already mowed and making adjustments in real-time.
•The Bosch Indego S+ uses their LogiCut system to mow in rows side-by-side from boundary to boundary.
•The Worx Landroid uses the AIA system to help navigate your lawn more effectively and efficiently.
The Main Components of a Robotic Mower System
A robotic lawnmower system can be broken down into 7 main components: the operating system, battery, wheels, chassis, cutting system, and boundary wire.
1. Operating System
Where all the magic happens, the PCB is the brains of a robot mower.
You wouldn't believe it, but this little circuit board is the most important part of your robot lawnmower.
Without it, you're left with a costly garden ornament.
Your mowers operating system is in charge of all the other components in the system and makes sure that they are all running in congruency.
2. Cutting System
Different models have different blade configurations.
However, the majority of robotic mowers use 3 pivoting razor blades attached to a rotating disk, as shown on the right of the above image.
A brushless DC motor is usually used to drive the cutting blade disk or the cutting blades directly, as seen on the left of the above image.
3. Wheels
Robot lawnmowers are generally driven by 2 large rear wheels designed for maximum grip and traction on slopes, slippery surfaces and uneven ground.
Different manufacturers take different approaches to wheel design, although they all either feature large spikes or large grooves designed to maintain traction and dissipate grass build-up.
The 2 large rear wheels are driven directly by individual brushless DC motors.
Free-rotating front guide wheels accompany the rear wheels.
Most models will have 2 front guide wheels, as shown on the left.
However, some models do come with a single guide wheel, as shown on the right.
4. Sensors
Sensors are the eyes and ears of a robotic mower. They are used to avoid obstacles, as a safety measure, and to keep within your properties bounds.
Most robotic lawn mowers are equipped with:
•Bump Sensor: Used to avoid obstacles
•Tilt Sensor: Automatically stops cutting blades if robot mower is in a compromised position
•Lift Sensor: Automatically stops cutting blades if the mower is lifted off the ground and send an alert to the owner as theft prevention
5. Battery
The power source of a robotic mower, most robotic lawnmowers use durable rechargeable Lithium-ion batteries from 18v-22v.
Most mowers will get around 60-90 minutes of mowing time per charge and require the same amount of time to recharge.
6. Charging Station
The charging base is where your robot mower will remain whenever it's not busy mowing, like a home base.
Almost all models in today's market will automatically return to the charging station using a guidewire to find their way back.
Many manufacturers sell robot mower garages that will attach to your base station to keep your mower out of the weather.
Some DIYers have used converted dog kennels to house their robotic mowers, which are often cheaper and looks far more natural in your garden.
7. Boundary Wire
The boundary wire is what your robotic lawnmower uses to navigate your lawn effectively.
You can use your guidewire to set no-go zones, separate mowing zones and isolate areas such as trees, garden beds and garden furniture.
Do Robot Mowers Work in Australia?
In Australia, the most common grass species is Buffalo, which a particularly stubborn and thick-bladed strain.
So, can robot lawnmowers cut Buffalo grass?
They certainly can, and as robotic mowers are designed to mow more frequently and keep your lawn at a fixed height, your robotic mower shouldn't have any issues getting through thicker grass types like Buffalo or St Augustine.
However, if your lawn has become overgrown, we'd recommend mowing it with a regular mower first and let your robotic mower take over where it will keep the lawn at a set height with its frequent mowing schedule.
Robot Mowers in a Nutshell
These robust little lawnmowers are designed to automate the tedious chore of mowing the lawn. In previous years the technology wasn't advanced enough to see widespread adoption.
As the technology has improved greatly in the last 5 years, they have become an ever more useful tool to have in your household.
A robot lawnmower can effectively save you hundreds of hours every year by automating the task of lawn mowing, leaving you extra time to spend with family, friends or to simply kick back and relax.
Robot lawnmowers have already taken off in certain countries in Europe, with almost 1 in 3 lawns being mowed automatically. They aren't as common yet in Australia.
However, the market is steadily growing each year, and as the technology advances, we'd expect a much wider adoption in Australia, similar to the European markets.
So now that you know how robot lawnmowers work, you'll be able to school your friends and family on the subject next time you see one in the neighbourhood!