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Lower costs, less CO2, more beautiful lawn: The municipality of Flieden relies on robotic lawnmowers for lawn care in the swimming pool and on its soccer fields.
Flieden – The robotic lawnmower runs its path in the Flieden stadium straight and almost silently. Weighing just 18 kilograms, it is not only compact, but also does its job without having to be controlled by a human. “When you install the robot, you determine the area that you want to mow,” explains Dirk Pfannenschmidt.
“This area can then be subdivided several times. We can assign up to 20 different mowing areas to each mower,” adds Dirk Pfannenschmidt. He is the manufacturer's key account manager and the main contact for the municipality of Flieden for technical questions. Once a mower has been installed, it passes on its knowledge to its robot colleagues.
Lower costs, better lawn – Flieden relies on robotic lawnmowers
“Once it's programmed, we clone the device. Then all devices have the same intelligence. Then I can divide a sports field like this into three areas, for example. Then I assign mower 1 to section 1, give it a working time and set the desired cutting height. Then I assign mower 2 to section 2, and so on.”
Once programmed, everything runs automatically: the robot detects its position via GPS, mows its paths and occasionally drives to a charging station. The model that the municipality of Flieden is currently using creates around 250 square meters per hour, so several hours have to be expected for a complete sports field. To prevent the lawn from becoming matted, it should be mowed every day if possible.
“With a conventional tractor lawn mower, you would collect the cut grass and drive it away – thereby removing nutrients and moisture from the soil. The robot leaves the grass lying there, which has the advantage that both nutrients and moisture are retained and you can save on fertilization in the summer,” explains Pfannenschmidt.
The project started around three years ago with a test area in the Flieden swimming pool and then on the sports fields. The test phase was successful – except for one small incident in the Schweben district: On the way to its charging station, the robot received the circular signal from the station just a few meters away.
“If it registers this signal, the robot assumes that it has a clear path to the station. Unfortunately, there was still the sausage stand between it and the station,” said Pfannenschmidt in a subsequent error analysis. So the robot didn't go to the charging station to charge, but rather – just like a human – to the sausage stand.
Meanwhile, the attempt to run over Mayor Christopher Gärtner (CDU) during the demonstration for the press goes virtually smoothly: the town hall boss, who is tentatively standing in the robot's way as an obstacle, is only lightly touched before the robot registers the obstacle, stops and turns around. “This device is currently programmed to drive in collisions. Since it is equipped with radar, it is also possible to set collision avoidance,” says Pfannenschmidt.
Background: robotic lawnmowers and hedgehog protection
“As of today, we haven’t killed a single hedgehog,” emphasizes Dirk Pfannenschmidt when asked Fulda newspaper. On the one hand, this is due to the type of blade installed. “We have a knife disc that is equipped with a sliding plate. The actual knife only protrudes a centimeter. That's enough for cutting. We don't behead any hedgehogs, which is what people often claim.”
On the other hand, the latest models of the robot are equipped with a camera based on artificial intelligence (AI). “As of today, this camera has saved around 200,000 images, including hedgehog dummies in all colors, shapes and sizes. If an obstacle appears, the camera compares it with the images and uses this to distinguish between living beings and objects. The robot then keeps a distance of 50 centimeters from a living being and 10 centimeters from an object.”
The robot is controlled and monitored by a municipal employee via an app. It is secured with an alarm system. If you pick it up without entering the correct code, it begins to whistle at 110 decibels. “Thefts practically never occur, also because there is no black market for spare parts. In 2021 we had four thefts in Germany. Three were vandalism, i.e. the robots were taken and thrown into the hedge somewhere,” says Pfannenschmidt.
Three robots are now in use on all six sports fields in the municipality of Flieden. There are also another three in the outdoor pool, making a total of 21. The robots run on a leasing contract, which includes maintenance costs. According to Pfannenschmidt, the community of Flieden is a pioneer in the Fulda district with this concept. According to the administration, the municipality saves around 92 percent of personnel costs through this deployment, although the personnel cannot be rationalized away but can be deployed elsewhere. The community had previously mowed the areas. The total cost savings are 41 percent, and 75 percent less CO2 is produced.
Mayor Gärtner is satisfied. “Even if some were initially skeptical, there is now positive feedback from all directions. Visiting clubs keep saying: 'What are you doing with your lawn? It looks really good.'” Yannik Freundlieb, groundskeeper at SV Flieden, also says: “We are very satisfied. It helps a lot to keep playing going and the result is a really neatly mown lawn.” And coach Christian Kreß also thinks: “It looks great. We have a lawn that other teams envy.”
Based on the positive experiences, the community can imagine other areas of application. “It would definitely be possible to use it in cemeteries. We are currently in the planning phase,” reports Thorsten Müller from the building authority. It's not just Flieden that relies on robots: The Schlüchtern city school is testing a cleaning robot in the sports hall.
