Open Access

Diese Masterthesis befasst sich mit der Entwicklung und Validierung von Inverter-Ansteuerverfahren zur Optimierung des elektrischen Antriebssystems von Elektrofahrzeugen. Zur Bewertung der Modulationsverfahren wurde eine komplett neue Simulationsumgebung in MATLAB aufgebaut. Das Antriebssystem ist in ein Invertermodell, ein nichtlineares Maschinenmodell und einem Batterie- und Zwischenkreismodell aufgeteilt. Für die Evaluierung werden verschiedene Kenngrößen, darunter die Verluste und Belastung der Komponenten, Oberschwingungen, die Common-Mode-Spannung und weitere, ausgewertet. Das Ziel ist die Optimierung des Antriebssystems hinsichtlich einer geeigneten Wahl der Modulationsverfahren in Kombination der Transistorschaltfrequenzen. Der Nutzer definiert eine frei wählbare Zielfunktion nach seinen Ansprüchen. Der Optimierungsalgorithmus sucht daraufhin die optimale Wahl der Inverteransteuerung, bei der die Zielfunktion ihr Minimum annimmt. Als Exempel wurden drei optimierte Betriebsstrategien: Verlustleistungsoptimierung, Optimierung nach der Zwischenkreisbelastung und Minimierung der CMV-Spannung abgeleitet. Die Verluste können im Maschinenkennfeld bei der in dieser Arbeit verwendeten Parametrierung um bis zu 33 % reduziert werden.

This research presents a comprehensive exploration of hydroponic systems and their practical applications, with a focus on innovative solutions for managing environmental and analytical sensors in hydroponic setups. Hydroponic systems, which enable soilless cultivation, have gained increasing importance in modern agriculture due to their resource-efficient and high-yield nature. The study delves into the development and deployment of the SensVert system, an adaptable solution tailored for hydroponic environments. SensVert offers adaptability and accessibility to farmers across various agricultural domains, addressing contemporary challenges in supervising and managing environmental and analytical sensors within hydroponic setups. Leveraging LoRa technology for seamless wireless data transmission, SensVert empowers users with a feature-rich dashboard for real-time monitoring and control. The study showcases the practical implementation of SensVert through a single sensor node, seamlessly integrating temperature, humidity, pressure, light, and pH sensors. The system automates pH regulation, employing the Henderson-Hasselbalch equation, and precisely controls liquid dosing using a PID controller. At the core of SensVert lies an architecture comprising The Things Stack as the network server, Node-Red as the application server, and Grafana as the user interface. These components synergize within a local network hosted on a Raspberry Pi; effectively mitigating challenges associated with data packet transmission in areas with limited internet connectivity. As part of ongoing research, this work also paves the way for future advancements. These include the establishment of a wireless sensor network (WSN) utilizing LoRa technology, enabling seamless over-the-air sensor node updates for maintenance or replacement scenarios. These enhancements promise to further elevate the system's reliability and functionality within hydroponic cultivation, fostering sustainable agricultural practices.

Printed electronics, due to its manufacturability using printing technology, allows for fabrication on large areas and the usage of flexible substrates and thus enables novel applications. Non-impact printing technology, such as inkjet-printing, permits for flexible, decentralized manufacturing of electronic devices and systems. This further facilitates split-manufacturing in security-critical electrical components, as well as a maximum in design flexibility in terms of free form factors and non-standardized structures with different geometrical sizes, reaching from a few micrometers up to several millimeters. Based on the technological benefits printed electronics offers, it provides an interesting counterpart to classical silicon-based electronics, which is usually densely integrated on miniaturized, rigid areas. By utilizing both technologies in a complementary manner, novel systems in the form of hybrid systems can be enabled. Whilst hybrid systems, incorporating passive printed components and electrically conductive wiring concepts, are already commercialized, complex printed systems, which also utilize active components remain rare. To enable more complex (hybrid) systems, various building blocks are required. This includes possibilities for lightweight, printed data storage, the capability to provide sustainable, self-powered printed components and especially circuits for secure, unique identification for holistic printed systems, deployed in the internet of things. The presented thesis focuses on inkjet-printed electronic devices, circuits and hybrid systems. It investigates solutions for current scientific questions in the area of efficient data storage, sustainable electronics and hardware-based security in printed electronics. For data storage, an inkjet-printed memristor is developed. The device is fully electrically evaluated with a focus on its data storage capabilities. Furthermore, the printed device is of special interest due to its easy manufacturability and integration capabilities. The experimental analysis reveals that the developed memristor is highly suitable as lightweight non-volatile memory device. In order to enable sustainable electronic systems, an inkjet-printed full-wave rectifier based on near-zero threshold voltage electrolyte-gated transistors is developed and fully electrically characterized. The circuit is capable for small alternating voltage rectification of low-frequency vibration energy harvesters in the sub-volt region. This provides an important building block in enabling sustainable, self-powered electronic systems. The inkjet-printed full-wave rectifier is evaluated by electrical simulation and experimentally. To tackle hardware-based security for printed electronics, two implementations for inkjet-printed physically unclonable functions are developed and presented. For unique identification, intrinsic variation in active printed devices are exploited. One implementation is based on a crossbar architecture, incorporating integrable electrolyte-gated transistor cells. The second implementation, the so-called differential circuit physically unclonable function, is based on inverter structures, which provide the basis for unique response generation. Both physically unclonable functions are evaluated using an electrical simulation-based approach and experimentally. The differential circuit approach is furthermore fully integrated within a silicon-based electronic platform environment and serves as intrinsic variation source in a hybrid system. The hybrid system physically unclonable function is fully verified regarding performance metrics and is capable to generate highly unique responses for secure identification.

In dieser Abschlussarbeit wurde die bisherige Spielstrategie des RoboCup3D-Clients an die durch den FatProxy möglich gewordenen perfekten Kicks angepasst. Dazu wurde die aktive Entscheidungslogik am Ball komplett überarbeitet und eine neue Positionierungsstrategie anhand der bisher verwendeten Architektur entwickelt. Die neue aktive Entscheidungslogik verwendet dabei eine neue, von den Mitspielerpositionen abhängige, Positionsberechnung und mehrere neue Bewertungsmethoden, die diese Positionen bewerten. Zusätzlich gibt es nun auch eine Funktionalität, die den neu benötigten vertikalen Schusswinkel für jede Position bestimmt. Für die neue Positionierung wurde eine Rautenformation gewählt, bei der die verschiedenen Rollen jetzt eigene Spielfeldbereiche zugewiesen bekommen, die sich teilweise überlappen. Diese Bereiche sind nötig geworden, da die Rollen sich jetzt weniger am Ball und mehr direkt am Spielfeld orientieren. Bei der zum Schluss durchgeführten Evaluation der Spielergebnisse zwischen neuen und alten Strategiekonfigurationen hat sich ergeben, dass die komplett neue Strategiezusammenstellung mit durchschnittlich zwei Toren Vorsprung gegen die alte Strategie gewinnt und damit besser mit den neuen Möglichkeiten interagiert. Mischt man neue und alte Strategiekomponenten hat das jedoch den gegenteiligen Effekt, da die Mischvarianten gegen die alte Strategie verlieren. Die neuen Komponenten benötigen also das gegenseitige Zusammenspiel, um effizient zu funktionieren.

Multiple-Input-Multiple-Output (MIMO) is a key technology in improving the angular resolution (spatial resolution) of radars. In MIMO radars the amplitude and phase errors in antenna elements lead to increase in the sidelobe level and a misalignment of the mainlobe. As the result the performance of the antenna channels will be affected. Firstly, this paper presents analysis of effect of the amplitude and phase errors on angular spectrum using Monte-Carlo simulations. Then, the results are compared with performed measurements. Finally, the error correction with a self-calibration method is proposed and its angle dependency is evaluated. It is shown that the values of the errors change with an incident angle, which leads to a required angle-dependent calibration.