A farmer can use sensors and wireless transfer to see which areas of the fields need to be watered and how much. ELLIIT Professor Björn Landfeldt and his colleague Emma Fitzgerald are supervising degree projects in collaboration with two companies, Sensative and Sensefarm.
Sensative, based in Lund, develops technology for smart cities in which small energy-efficient sensors are linked over the internet of things to give information about energy consumption, traffic congestion, the quickest route home, etc. One of the company founders, Anders Hedberg, realised that the technology could also be used to benefit agriculture, and started a sister company, Sensefarm.
“We have collaborated with Sensative, Anders Hedberg and his colleagues, right from the start – both in regional projects here in Skåne and in EU projects. And in recent years we have also collaborated with Sensefarm”, says Björn Landfeldt, professor in network architecture at Lund University, whose post is partly under the auspices of ELLIIT.
LoRa, a standard protocol for radio communication over long distances, is used for wireless transfer. It is necessary to use long-range signals in the countryside, where the fields are large and base stations are separated by considerable distances. Further, LoRa has a low energy consumption, which is important where it is too expensive to lay electrical cables, and thus batteries or solar cells must be used as sources of energy. It is, however, difficult to achieve sufficient coverage. A large barn, storage silo or a hill can be sufficient to create a radio shadow, and weaken or completely block the signal.
“In two degree projects in network technology, we have looked at different ways to solve this”, says Björn Landfeldt.
The first was carried out by Eva Jurado, who developed an optimisation tool, a mathematical model, showing how base stations should be located to achieve as high a degree of coverage as possible.
“She also tested the model in Lund, an urban environment. Since there were already base stations here, she was able to verify the model. She worked in collaboration with Sensefarm, and Anders Hedberg attended the presentation where he demonstrated an implementation that minimises cost for farmers”, says Björn Landfeldt.
In the other degree project, supervised by Senior Lecturer Emma Fitzgerald, Daniel Lundell built up a mesh network. Instead of using buried electrical cables and deploying several base stations, coverage for the region uses several radio modules, or nodes. The modules use wireless to communicate with each other, and information from the sensors can be transmitted over the mesh network to the node that is connected to the internet at that moment.
“This technology has many advantages: it doesn’t need buried fibres or cables, and the nodes can be distributed over large regions”, says Björn Landfeldt.
One clear and immediate application for the farmer uses moisture sensors at selected locations in the fields to determine where water is needed and how much. The information is passed through the internet directly to the farmer’s computer or mobile phone. The advantages are not only better use of water resources but also crops with high quality.
Thus research and degree projects in network technology, wireless systems, and the internet of things are making important contributions to the smart agriculture of the future.
Björn Landfeldt, professor in the Networks and Security group at the Department of Electrical and Information Technology, Lund University. Emma Fitzgerald, senior lecturer in the Networks and Security group at the Department of Electrical and Information Technology, Lund University.