Towards UAV-assisted monitoring of onshore geological CO2 storage site

Scientists all over the world look for solutions to reduce greenhouse gas emissions in an effort to achieve proclaimed emissions reduction targets. An intriguing candidate with the potential to make a substantial contribution to this attempt is carbon capture and storage (CCS). The key advantage of CCS is that it provides the possibility to make a significant impact on the reduction of anthropogenic carbon dioxide (CO2) emissions from power plants and carbon-rich industry processes while maintaining existing fossil fuel energy infrastructure. The technique could therefore be used as a transitional solution until fossil fuels can be eliminated from the energy generation mix, and the energy efficiency of industrial processes as well as appliances and products is further improved. Like other technologies, CCS comes with its risks and rewards. To minimize possible negative impacts on humans as well as on the environment, it is necessary to understand the risks and to address them accordingly. A range of monitoring solutions for geological CO2 storage sites is available. However, a cost-effective solution for the regular observation of atmospheric CO2 concentrations (or tracer concentrations) of large areas above onshore geological CO2 storage sites has yet to be developed. This thesis discusses the use of a helicopter unmanned aerial vehicle (UAV) to fill this gap. The robot platform and its autopilot are designed to cope with ongoing sensor developments in addition to providing safety features necessary for the beyond line-of-sight operation of the UAV. The design focuses on the use of commercial off-the-shelf components for the aerial platform in order to shorten the development time and to reduce costs. The autopilot does neither enforce a specific helicopter model nor defines a set position estimation unit to be used. Access to the control loop enables low-level extensions like obstacle avoidance to be implemented. The developed solution allows the monitoring of an area of approximately 750m2 with one set of batteries in one altitude with a spatial resolution of 2m by 2m. Experiments show that point source leaks of as low as 100kg CO2 per day can be detected and their source located. As opposed to autonomous take-offs of the helicopter UAV, autonomous landings on small dedicated helipads require an accurate localization system. A time difference of arrival (TDOA) based acoustic localization system which is based on planar microphone arrays with at least four microphones is proposed. The system can be embedded into the landing platform and provides the accuracy necessary to land the UAV on a helipad of the size of 1m by 1m. A review of existing TDOA-based approaches is given. Simulations show that the developed approach outperforms its direct competitors for the targeted task. Furthermore, experimental results with the developed UAV confirm the feasibility of the introduced method. The effects of the sensor arrangement onto the quality of the calculated position estimates are also discussed. In order to combine robotic-assisted monitoring solutions and other monitoring strategies (e.g. sensor networks and individual sensors) into a single solution, it is necessary to have a framework which allows next to the measurement data analysis also the management (path changes, robot behavior changes, monitoring of internal robot state) of possibly multiple heterogeneous mobile robotic systems. A modular user interface (UI) framework is proposed which allows robots from different vendors and with various configurations next to individual sensors and sensor networks to be managed from a single application. The software system introduces a strict separation between the robot control software and UIs. UI implementations inside the UI framework can be reused across robot platforms, which can reduce the integration time of new robots significantly. The end user benefits by being able to manage a fleet of robots from various vendors and being able to analyze all the measurement data together in a single solution

Crop Harvesting

In der Saison 2017/2018 wurde im Bereich der Halmgutbergung, im Vergleich zum Vorjahr, ein Zuwachs der Absatzzahlen erreicht. Deutlich zeichnet sich dies z.B. bei den Ballenpressen mit insgesamt 15 % ab. Für die Landwirte war es aber ein schwieriges Jahr durch gesunkene Milchpreise bei gestiegenen Erzeugerpreisen, die vor allem durch die Dürre in vielen Bereichen Deutschlands hervorgerufen wurden. Die Landmaschinenhersteller haben das Jahr u.a. genutzt, um die in 2017 auf der Agritechnica oder Husker Harvest Days vorgestellten Produkte zu erproben. So befinden sich erste Testmaschinen der selbstfahrenden Ballenpresse von Vermeer und der mit Raupenfahrwerk ausgestattete Feldhäcksler von Claas im Praxiseinsatz bei ausgewählten Kunden. Bei den selbstfahrenden Feldhäckslern werden neue Modelle mit gesteigerter Motorleistung angeboten, ebenso gibt es einen neuen Vorsatz zur Bergung von Maisstroh zur energetischen Verwertung.In the 2017/2018 season, sales figures in the field of forage harvesting increased compared to the previous year. In balers there was a considerable increase of 15 %. For dairy farmers, however, it was a difficult year, with lower milk prices and higher producer prices, mainly due to the drought in many areas of Germany. Agricultural machinery manufacturers used the year to test the products presented at Agritechnica or Husker Harvest Days in 2017. Selected customers are using the first test machines of the self-propelled Vermeer baler and the Claas forage harvester equipped with crawler tracks in practice. The self-propelled forage harvesters offer new models with increased engine power, as well as a new attachment for collecting corn straw for energy production

Modellierung des Spritzfächers einer Pflanzenschutzdüse mit der Diskrete-Elemente-Methode

Die Prüfverfahren von Applikationstechnik für Pflanzenschutzmittel sind aufgrund der meist erforderlichen Praxisversuche sehr aufwendig. Aus diesem Grund ist der Einsatz von Simulationsmethoden wünschenswert. Ein Gesamtmodell zur Abbildung einer Pflanzenschutzdüse und des zugehörigen Spritzfächers konnte bisher nicht entwickelt werden. Jedoch existieren für einzelne Teilprozesse zur Simulation der Abdrift in der CFD (Computational Fluid Dynamics) bereits Modelle, die aber oft nicht vollständig validiert sind. Für ein Gesamtmodell eignet sich die Diskrete-Elemente-Methode (DEM) u. a. aufgrund der Analogie zwischen Tropfen und den simulierten Partikeln sowie der einfachen Kontakterkennung bei der Benetzung. Die Abbildung des Sprühkegels mit der DEM stellt die erste Herausforderung dar, ein Ansatz hierfür wird im vorliegenden Beitrag vorgestellt. Auf Messdaten basierend wird in der Simulation ein Tropfenspektrum 100 mm unterhalb der Düse erzeugt und zur Validierung das Spektrum sowie die Querverteilung 500 mm unterhalb der Düse gemessen. Das Tropfenspektrum zeigt eine hohe Übereinstimmung, während bei der Querverteilung leichte Abweichungen zur Messung vorliegen

RobotUI - A software architecture for modular robotics user interface frameworks

Modern robotics frameworks are based on modular architectures that enable them to cope with the complexity and diversity of today's robotics applications. The encapsulation of the framework modules is the key to their reuse in various robotics scenarios