Dirt-resistant bearings in robots for weed control

EcoRobotix, a Swiss Agricultural Technology company develops, manufactures and distributes innovative agricultural machinery using AI precision. The aim is to offer accurate, safe, reliable and affordable robotic solutions that simplify farmers' lives and produce healthy food. The start-up company, which was founded in 2014, designed its first in-house development, a weeding robot that travels autonomously across fields and destroys weeds with targeted precision.

The flagship technology uses advanced computer vision, artificial intelligence, and ultra-high-precision spraying systems to identify individual weeds and crops in real time, applying treatments only where needed.

Ecorobotix has become a global leader in precision agriculture, providing innovative spraying and crop-care technologies that support more sustainable farming practices while improving not only productivity but also profitability for farmers around the globe.

Requirement, challenge and solution

Autonomous field vehicle between crop rows on a field.

Requirement

Being in the agricultural sector, the components that are used need to be robust, durable and reliable. The customer was looking for parts which are cost-effective, light-weight and resistant to dirt and dust, which eliminates a lot of conventional parts such as metal bearings.

All of our parts are lubrication-free which is another requirement for the customer, to reduce the contamination onto the soil.

EcoRobotix agricultural robot with igubal support in a field.

Challenge

The robot weighs around 130 kilograms, moves independently, orientates and positions itself using GPS and a camera. An image capture system recognises whether and where the weeds are located.
The robot is equipped with an RTK GPS for exact positioning. It is fully controlled and configured using a smartphone application. And solar operation makes the robot completely self-sufficient in terms of energy supply, even when the sky is overcast.
Once the robot has identified a weed, it sprays a microdose of herbicide onto the weed with pinpoint accuracy using two robot arms. Rod ends are used to ensure that the two robot arms have the desired manoeuvrability. Because they are used in fields, they need to be protected against dirt and dust and robust. The customer was also looking for a lightweight and economical solution.

igus igubal joint bearing on a robot assembly for agriculture.

Solution

The spherical plain bearings used in the robot arm are igubal® rod ends, which are corrosion-free, lightweight, cost-effective and can withstand temperatures from -40 to +200 degrees Celsius. They are also resistant to media, UV rays, radioactive radiation, dirt and dust. Unlike their metal counterparts, the rod ends are able to absorb vibrations.
Once installed, the bearings require no further attention - thanks to their lubricant-free design. Unlike lubricated metal bearings, no resin or paste-like mixtures are formed that bind dirt to the bearing point. Even with extreme contamination, the igubal® bearing elements do not require a seal. This applies to both fine dust and coarse dirt. The polymer spherical plain bearings are up to 80 per cent lighter than metal bearings. Twelve rod ends are fitted per robot arm, which equates to 24 such rod ends for two arms. This significantly supports the lightweight constructions and at the same time reduces energy consumption.

We want an economical and ecological solution. [...] In addition, plastic is produced in an energy-efficient way, transport routes are short and, most importantly, the quality at igus® is right.

Fabien Grevoz-Sicurani

Production Manager at EcoRobotix

Applications in use in the agricultural industry

Agricultural bearings in Lemken machines

No more wasting time with self-lubricating bearings

igus® has been successfully collaborating with Lemken since 2008. Various Lemken machines are equipped with igus plain bearings, among them the cultivator Karat 9. In the overload elements, the metal bearing points previously used had to be lubricated up to one hour per day to prevent wear and corrosion. By switching to lubrication-free polymer plain bearings, the farmer saves valuable time. Furthermore, the dirt resistance and stability of the plain bearings increase service life and dependability.

The grubber loosens the soil in the field behind the tractor.

Agricultural bearings in bale trimming machines

Heavy load up to 15 tons is made possible

Maintenance-free and resistant to dust and dirt, the iglidur® G plain bearings are used in hinges, locking systems and hydraulic cylinders of bale trimming machines from Optimal-Vertrieb Opitz. They replace red brass solutions, that were produced in-house and required both a relatively large installation space and lubricants that polluted the environment. The new polymer bearings need no lubrication and withstand all edge loads without problems.