Periodic Reporting for period 1 - ENTRAP (Energy Harvesting for Precision Agriculture Applications)
Período documentado: 2019-07-01 hasta 2022-06-30
Energy harvesting in precision agriculture applications (ENTRAP) was a Marie Skłodowska Curie Action individual fellowship awarded to David Blažević and Tampere University. The aim was to develop a small wearable device which can convert the natural motion of farm animals into electrical power. In the precision agriculture management concept, or more specifically precision livestock farming, smart wearable devices are being used to manage livestock production. Farm animals can be equipped with special smart collars, leg straps or ear tags with embedded health or wellbeing monitoring sensors (temperature, disease, geolocation etc.). These smart wearables report the animal’s health status or location wirelessly to the farmer. Millions of smart farming devices are being marketed today in the EU and all are powered with batteries with limited capacity (finite lifetime batteries). Battery manufacturing is known to be unsustainable and a toxic polluting practice with low recycling rates which produces negative effects on the ecosystem. Thus, the goal of project ENTRAP was to replace batteries in these wearable devices with a small electromechanical generator. The generators use a moving permanent magnet mechanism which reacts to simple animal movement like a cow’s step or ear flap and – based on Faraday’s principle of electromagnetic induction– converts that kinetic energy into electrical energy by inducing voltage in a coil. To design such a generator animal locomotion was first measured and analyzed and then a numerical model was developed which could take recorded animal movement as an input. Computer simulations were performed and based on the results, laboratory prototypes were built and tested on field with free grazing cattle. The conclusive result of action ENTRAP is that certain low power smart farming devices could be completely powered by animal locomotion. For more energy intensive applications, like virtual fencing, significant increases in battery lifetimes could be achieved. The action has also shown that these generators could be made cheap, reliable, and easily integrated with existing smart farming devices.
During the action’s implementation research was performed in 4 interconnected work packages each with its own objective. A detailed state of the art research was performed in the field of animal kinetic energy harvesting and electromagnetic energy harvesting. This work resulted with an excellent in-depth understanding of the field and sparked new research ideas to be implemented in the action. In parallel with this work contacts were established with potential experimental cattle and goat farms. Animal locomotion measurement experiments were designed with special attention to design of the animal wearables. At the end of the first year of the action animal measurement experiments were performed in Tampere at the Ahlman dairy farm during which movement of cattle’s legs, necks and ears during free pasture grazing was recorded with portable wireless accelerometers. This data was recorded in high detail and analyzed with kinetic energy harvesting mechanisms in mind. This process resulted with specific frequencies, acceleration magnitudes and movement profiles associated with cattle walking, ear flapping etc. A numerical model was developed in the Electromechanics group of Tampere University, which was used as a simulation tool for designing and optimizing animal kinetic energy harvesting prototypes. Based on the results a prototype of an energy harvester was developed in the laboratory with 3D printing and manual assembly techniques and subjected to tests on a laboratory shaker set-up as well as with human walking experiments. The prototype harvester was then assessed in two field trials at the Ahlman dairy farm where the generator was strapped to the leg of a an eastern Finncatle cow Pinja. In the first field trail the harvester was built into a leg strap wearable with an embedded voltage logger used to monitor the generators performance. In the second trial the harvester was used to power a Bluetooth beacon via a power management circuit optimized for this specific application. The generator proved to be functional and respond in agreement with the cow’s movement while also powering the Bluetooth beacon. The transmission would occur every time the cow would move her position on the field. The generator intermittently charges an onboard capacitor until a predefined voltage level is achieved. At that point the power management circuitry releases the energy to the beacon and power it continuously for 18s (outputting 13 mW of power). The main result from this research action is that a bottom-up design used in this action can result with kinetic energy harvesting device which can enable a low-power electronic device, such as a Bluetooth beacon, to be completely autonomous. Device designs have been disclosed to the University innovation services in three separate reports and contacts have been established with interested private companies working in the field of animal geolocation and virtual fencing. The results of the field trials and animal measurements have been disseminated at a dedicated energy harvesting conference and at the European precision livestock farming conference.
The project has reached its end with all objectives and goals reached. In three years of dedicated research the action has contributed to the state of the art about animal kinetic energy harvesting by introducing a bottom-up kinetic energy harvesting design for farm animals. Animal acceleration measurements recorded in high detail have been made available in an open data repository (https://etsin.fairdata.fi/) which can be freely accessed by academia and the industry. The action’s results could potentially be interesting to existing and future smart farming wearable manufacturers. The extensive use of long-lasting kinetic energy harvesting generators in the smart farming sector could substantially reduce the use of finite lifetime batteries and reduce toxic waste and volume of mining for battery materials. Through various communication activities and channels diverse audiences in Finland and Croatia have been introduced to the topics of Marie Skłodowska Curie Actions and kinetic energy harvesting. The action has made a strong impact on the researcher’s career with a multidisciplinary career restart project. The researcher was able to act independently and build a new network of academic and industry partners alike. Through various organized training activities and hands-on learning the researcher has been able to widen his knowledge and increase his competitiveness.