ERIKSBO PLANT NURSERY - Autonomous Spraying Robot
Eriksbo Plantskola in Sweden contacted Exobotic for the development of a fully functional spraying robot to be used on the gravel area around their plant beds. Previously, these zones which are not covered by a plastic tarp and cannot be mowed, were sprayed every two months with a very efficient but not so ecological herbicide liquid. In their goal to continuosly evolve towards more ecological and sustainable practices, Eriksbo aims to start using a biological-based herbicide solution. To guarantee the same level of efficiency in controlling the weeds, this solution will need to be applied on a bi-weekly basis.
While manualy spraying around 15km of borders 2-3 times per year was still acceptable, doing this every two weeks would make the application costs explode, especially taking in the level of precision with which the liquid would need to be applied given the high price per liter of these ecological herbicides. During a study trip at Belgian tree and plant nurseries, the owner of Eriksbo Plantskola saw our robot at work and contacted Exobotic with the challenge to develop a robot to automate this task.
“With ecological herbicides, the frequence of spraying has to go way up.
With 15km of plant borders to spray on a bi-weekly basis, we had to look into automating this task.”
After some detailed discussions about the use of the robot, the environment, the technical requirements and the daily operations at Eriksbo Plantskola, a concept became clearly defined. Much more than being the combination of technical components, Exobotic aims todeliver a solution that is fully integrated, functional and easy to use.
Read on to discover what exactly goes into delivering such an A-to-Z solution.
The plan
Generally, the solution can be split up into two main elements: an autonomous platform, and an inteligent spot sprayer.
Starting from an analysis of the needs of the customer and taking into account their wish for a relatively short timeline, we decided to use an existing base electromechanical platform to build upon further. The ideal choice for this is the Amiga autonomous vehicle, developed for small-scale farming by the Californian company Farm-NG. While being kept simple and functional, this four wheel drive platform with skid-steer turning can carry up to 200kg for multiple hours and has proven its reliability with over 50 platforms in daily use across the US. The robot for Eriksbo, which they already nicknamed Elon, is the first commercially used Amiga in the EU.
Exobotic will build a navigation and user interface layer on top of this platform to make it fit the needs of Eriksbo.
While the spraying frequency has to be bi-weekly, we designed the solution to be able to spray the full lenth of borders within one week, covering a portion of this every day. To enable this, a detailed route map needs to be created for the robot to follow every day of the week, which can be done via an intuitive teach-and-repeat functionality. Combining this function with the accuracy of RTK GPS positioning ensures that the robot precisely follows the designated gravel border, even if it isn’t perfectly straight.
The sprayer system which will apply the herbicide to the gravel zones is co-developed with ILVO (Flemisch Agriculture Research Intitute) and is integrated on the Amiga base platform. Not happy to just stiock a standard sprayer on top, the spotspraying system is fitted with an image processing capabilities to detect only the weeds growing in the gravel zone. This is done using an NDVI vegetation index which assesses the amount of photosynthesis in a plant. While sounding complex, this analysis allows to only spray the herbs and reduce herbicide use, resulting in a more ecological and economical solution.
Combining a robot that autonomously follows a predefined route with an intelligent spotsprayer is already an impressive challenge, but Exobotic doesn’t stop there. In our aim to make our solutions fully functional and ready to use, we implement the necessary safety guidelines and add an intuitive user interface. This contains the option to send alert for various reasons, buit also the ability to go back to it’s home location when batteries or the sprayer tank is nearly empty.
As its home location is within a covered shed, this also means seamlessly switching from GPS to visual navigation.
This is an ongoing project and updates will be added throughout the development of this solution.
