Robot mower
Robotic mowers look like miniature cars. They are used to mow the lawn without human assistance. A high degree of autonomy characterises the devices, which are able to independently recognise where they need to mow. There are different models in all possible price ranges. However, unlike a normal lawn mower, a robotic lawnmower must first be installed. Most models use a so-called orientation cable that is buried in the lawn and shows the robotic lawnmower where to cut the grass. Find out more about the robotic lawnmower, the brilliant helper for garden and lawn care!
For whom does it make sense to buy a robotic lawnmower?
Mowing robots, also called lawn robots, are particularly suitable for large gardens. Such devices are also useful in old age, when even the maintenance of small green areas is difficult. For people who are less mobile than in their younger years, this is a way to relieve them of the burden.
The following applies to the purchase: the larger the garden and the more uneven the terrain, the more expensive the equipment. Nevertheless, they combine advantages for which even higher investments are worthwhile:
- Independent mowing
- Lower noise level than a conventional lawn mower
- Obstacles are detected automatically - depending on the model and type of obstacle
- Automatic recharging
- Integrated theft protection
Since robotic lawnmowers are transportable devices, there is always a risk that they will be stolen. Most devices can therefore only be used in their own charging station for protection, so the thief would have to dig up the entire boundary wire to dismantle the station. More expensive models also use the built-in GPS sensor as a location tracker, so the owner can always see where the device is. In addition, there is PIN code protection (like on a phone) without prohibiting changes to the unit's settings.
How is a robotic lawnmower installed?
The first step is to choose a suitable location for the charging station, which must be close to a power socket and have sufficient free space. It is advisable that the robotic lawnmower is neither in the sun nor exposed to rain.
The next step is to lay the entire boundary wire in the lawn where mowing is to take place. The wire must be underneath the lawn so that people or animals cannot trip over it and get caught. This is generally not a problem, as the cable will grow over after a few weeks. It may well happen that - if the garden is very large - the cable supplied is not enough. In this case, extension sets must be obtained from the manufacturer. This is also the case if the garden is very winding or there are many objects to loop around.
Optimum conditions for robotic mowers
The best conditions for using a robotic lawnmower are level free lawns that are not covered with obstacles. In this case, installation is relatively simple: the boundary wire supplied is inserted into the ground along the edge of the lawn using the pegs provided. This way the robotic lawnmower knows where to mow. There are also more expensive models that work with GPS. These usually cost thousands of euros and are only recommended for private use in very large areas that are similar in size to a sports field. Basically, most models are aimed at owners of areas up to 1,000 m². Professional machines are designed for 1,000, 2,000 and more square metres.
Slope - a misleading term
According to experts, a slope already exists if there is more than a 2 % gradient. This means that for a 10-metre lawn there should be a slope of 20 cm. So if you live in the Alps, it would be better to go straight for a more expensive model. These are designed to cope with slopes of up to 50 %. For everyone else, slopes of up to 15 % are no problem for the devices. The majority of the machines can manage between 25 and 35 %. This can be measured relatively easily by using a folding rule or tape measure or a smartphone with a spirit level app.
How do the boundary and orientation wires work?
Boundary wires are there to show the robotic lawnmower where it can mow. Good models also have a programme for edges. This ensures that the robotic lawnmower works thoroughly on the lawn edges so that you no longer need an additional trimmer. The aforementioned alternative models with GPS sensor work without the cable. The advantage of this is that the robotic lawnmower is suitable for use on other properties or areas, so that, for example, a neighbourhood association can purchase a robotic lawnmower together. The disadvantage of GPS models is that the battery must be charged manually.
Robot mower in use
The lawn is mown continuously by the robotic lawnmower. This results in a uniform lawn appearance that always looks well-groomed. Important factors are the maximum area for which the robotic lawnmower is designed and the installed drive. It is a bad idea to use a robotic lawnmower that is too small for the corresponding lawn area. It is then not possible to mow the lawn in the appropriate cycles. In addition, the gearbox and the robotic lawnmower will generally wear out faster. Most models have settings that allow the user to define certain days or certain times of the day when the lawn is mowed.
How to mow separate lawns
If the lawn consists of several lawn areas, it is essential to have a connecting wire or guide wire that is laid between the individual areas. The robotic lawnmower uses the wire to find its way to the next area. This setting is called the multi-zone setting.
What are the movement patterns?
The most common movement patterns are:
- Parallel tracks
- Spiral travel
- Free movement patterns
When travelling in parallel tracks, the lawn is mown in the same way as a garden owner usually does: in one direction, then back again parallel to the created track and so on... The mowing takes a little longer than if the robotic lawnmower were to travel cross-country and the lawn looks less well-kept because edges are visible.
During the spiral drive, the robotic lawnmower draws an ever larger circle around its starting point until at some point all areas have been covered. In tests, contrary to expectations, the free (random) drive of the robotic lawnmower proved to be the most suitable. Here the cutting pattern was tidiest and there was a time saving.
Are robotic mowers safe?
In theory, robotic mowers are safe. This is because they are equipped with a variety of sensors that detect if there are objects on the lawn:
- Lift sensor: detects when the device is lifted and stops the cutting blades.
- Tilt sensor: If the machine tips over or is too inclined, the blades are stopped.
- Slope sensor: Detects if the slope exceeds the robotic lawnmower's ability and changes the direction of travel if this is the case.
- Impact sensor/collision sensor: If the robot collides with an object, it reverses and changes direction.
- Obstacle sensor: Impending obstacles are detected early so that the robotic lawnmower changes direction.
- Rain sensor: Rain is detected and the robotic lawnmower either returns to the charging station and remains there or acts as instructed (not all robots support mowing in rain).
Despite the sensors, there have been isolated accidents in the past. Therefore - regardless of manufacturer promises - an explicit warning should be given:
NEVER leave children or small animals or low objects on the lawn when a robotic lawnmower is nearby!
Link to Smart Home
Well-known manufacturers offer apps for smartphones with which the robotic lawnmower can be controlled by voice. Google and Amazon also offer support by transmitting the commands via a smart speaker. There are certainly manufacturers who even cover entire garden systems, such as lawn sprinklers, motion detectors, automatic irrigation systems. Here, linkages are even easier.
Mowing robot FAQ: Questions and answers about the industrious garden helper
How is a robotic lawnmower maintained?
The robotic lawnmower is cleaned from time to time and sprayed with water from below. As soon as the blades become blunt, they must be replaced. However, replacing the blades is time-consuming and expensive. Therefore, manufacturers point out that the blades generally wear out less quickly over time if the grass is no longer too tall.
How noisy is a robotic lawnmower?
A robotic lawnmower makes less noise than its larger relatives, the classic lawnmowers. For the most part, the noise level is below 70 decibels. By comparison, a normal lawn mower produces about 80 decibels of noise. Since 10 decibels more means a doubling of the noise level, this means conversely that a robotic lawnmower is half as loud as a normal lawnmower.
What happens to the mown lawn?
The mown lawn remains in place as mulch on the lawn. This has the advantage that the lawn is fertilised in a natural way.
Is it advisable to mow the lawn even when it rains?
No. No matter what the manufacturers promise on their websites or in their brochures: Mowing the lawn in the rain is not advisable. The reason for this is that the cutting blades wear out significantly faster. On top of that, wet grass gets caught in the gearbox and cleaning becomes more frequent. Most models stop working when it rains and do not return to the charging station themselves.
Is it permissible to use robotic lawnmowers more at night or on weekends?
Like lawn mowers, robotic lawnmowers fall under the "Equipment and Machinery Noise Protection Ordinance". This means that robotic lawnmowers may only be used during the day if you live in densely populated residential areas.
Which manufacturer is recommended?
During the research for this article, we noticed one manufacturer with more positive mentions, namely iMow. Its robotic lawnmower cuts very carefully and is robust, copes well with uneven surfaces and is quiet. However, at around €1,800 (as of 23.10.2019), it is an investment that should be well considered. The advantage here is that even large areas can be worked over, with talk of a size similar to football pitches.
Is it necessary to take out extra insurance for the robotic lawnmower?
In most cases, the robotic lawnmower is already covered by the household insurance. If in doubt, it is advisable to contact the insurance agent of your choice or the insurance company with which you have taken out insurance.
What type of battery is used in robotic lawnmowers?
For most robotic lawnmowers, manufacturers use a lithium-ion battery. Such a battery lasts at least five years. A lead-acid battery is cheaper, but allows ten times fewer charging cycles. Accordingly, lead-acid batteries are not recommended. There are also robotic mowers where the charging station is powered by solar cells. This makes for a climate-neutral and environmentally friendly lawnmower. Amateur do-it-yourselfers can also do this themselves.
Conclusion
The use of robotic mowers is recommended for anyone with a large garden. Care should be taken with children and small animals so that they keep their distance from the device as a precaution. Properly configured, a robotic mower is a great help in everyday garden and lawn maintenance. It is quieter and more environmentally friendly than a normal lawn mower. Through the optionally available link with Smart Home, it is possible to monitor the robotic lawnmower from anywhere.
