07 Fakultät Konstruktions-, Produktions- und Fahrzeugtechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/8
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Item Open Access Driving profiles of light commercial vehicles of craftsmen and the potential of battery electric vehicles when charging on company premises(2024) Heilmann, Oliver; Bocho, Britta; Frieß, Alexander; Cortès, Sven; Schrade, Ulrich; Casal Kulzer, André; Schlick, MichaelThis paper examines the extent to which it is possible to replace conventional light commercial vehicles in the heating, ventilation and air conditioning and plumbing trade with battery electric vehicles with an unchanged usage profile. GPS trackers are used to record the position data of 22 craft vehicles with combustion engines from eleven companies over the duration of one working week. Within this paper, various assumptions (battery capacity and average consumption) are made for battery electric vehicles and the charging power on the company premises. The potential of battery electric vehicles is evaluated based on the assumption that they are charged only on company premises. Using the collected data and the assumptions made, theoretical state of charge curves are calculated for the vehicles. The driving profiles of the individual vehicles differ greatly, and the suitability of battery electric vehicles should be considered individually. Battery capacity, vehicle energy consumption and charging power at the company have a substantial influence on the suitability of battery electric vehicles. Furthermore, there are differences between vehicles that can charge on the company premises at night and those that cannot or can only do so on some days.Item Open Access Comparison of driver models for powertrain test benches using a digital twin(2023) Schilling, Jannes; Wilmsen, Jan-Michael; Nitschke, Paul; Reuss, Hans-ChristianItem Open Access Environmental impact assessment and classification of 48 V plug-in hybrids with real-driving use case simulations(2022) Frambach, Tobias; Kleisch, Ralf; Liedtke, Ralf; Schwarzer, Jochen; Figgemeier, EgbertPlug-in hybrid electric vehicles (PHEVs) are commonly operated with high-voltage (HV) components due to their higher power availability compared to 48 V-systems. On the contrary, HV-powertrain components are more expensive and require additional safety measures. Additionally, the HV system can only be repaired and maintained with special equipment and protective gear, which is not available in all workshops. PHEVs based on a 48 V-system level can offer a reasonable compromise between the greenhouse gas (GHG) emission-saving potential and cost-effectiveness in small- and medium-sized electrified vehicles. In our study, the lifecycle emissions of the proposed 48 V PHEV system were compared to a conventional vehicle, 48 V HEV, and HV PHEV for individual driving use cases. To ensure a holistic evaluation, the analysis was based on measured real-driving cycles including Global Position System (GPS) map-matched slope profiles for a parallel hybrid. Optimal PHEV battery capacities were derived for the individual driving use cases. The analysis was based on lifecycle emissions for 2020 and 2030 in Europe. The impact analysis revealed that 48 V PHEVs can significantly reduce GHG emissions compared to vehicles with no charging opportunity for all use cases. Furthermore, the findings were verified for two vehicle segments and two energy mix scenarios. The 48 V PHEVs can therefore complement existing powertrain portfolios and contribute to reaching future GHG emission targets.Item Open Access Smart data preprocessing method for remote vehicle diagnostics to increase data compression efficiency(2022) Görne, Lorenz; Reuss, Hans-Christian; Krätschmer, Andreas; Sauerwald, RalfThe increasing number of functions in modern vehicle leads to an exponential increase in software complexity. The validity and reliability of all components must be ensured, making the use of appropriate vehicle diagnostics systems indispensable. The purpose of such systems is to collect and process data about the vehicle. To find issues during vehicle development, the OEMs will usually have a development fleet of thousands of vehicles. The challenge for diagnostic systems is to detect issues during these tests, as well as collecting as much data as possible about the circumstances that led to the fault. A single-vehicle produces hundreds of gigabytes of data per month. The required data bandwidth cannot be fulfilled by current mobile network subscriptions as well as WIFI or cable-based infrastructure. This limits the amount of data that can be collected during field tests and hinders big data analysis like AI training or validation. Hence a software solution for data reduction is necessary. The authors present a method for data handling that drastically reduces the amount of data consumption and optimizes the transfer delay between a remote-diagnostic systems and the cloud. Using a pipeline of data preprocessing as well as an established compression algorithm, the amount of transmitted data is reduced by a factor of nearly ten. This method will allow to collect more data in field testing and improve the understanding of issues during vehicle development.Item Open Access Parametrierung und Optimierung eines Fahrreglers mittels virtuellem Antriebsstrangprüfstand(2022) Veith, Jan-Michael; Schilling, JannesHeutzutage kann ein Großteil der Fahrzeugkomponenten und -funktionen, welche nicht am Prüfstand real aufgebaut sind, durch Simulationsmodelle realitätsnah abgebildet werden. Damit können komplexe Fahrmanöver am Prüfstand dargestellt werden, um die Anzahl an Prototypenfahrzeugen reduziert zu können. Einen essenziellen Beitrag zur Qualität der Messergebnisse liefert die Simulation des Fahrers, bestehend aus Quer- und Längsregler. Grundlage für einen realitätsnahen Fahrregler bildet eine umfangreiche Parametrierung. Um diese Parametrierung vornehmen zu können, muss der Prüfstandsingenieur Wissen über die Dynamik des Gesamtsystems haben und ist damit auf einen aufgebauten Prüfling am Prüfstand angewiesen. Mit dieser Arbeit soll eine virtuelle Prüfstandsumgebung bereitgestellt werden, welche die Systemdynamik durch Antriebsstrangersatzmodelle im Vorfeld oder zu Beginn der Inbetriebnahme des Prüflaufes abbildet. Die virtuelle Prüfstandsumgebung setzt sich aus den Simulationsmodellen der Realfahrtsimulation des Prüfstands und den Antriebstrangersatzmodellen zusammen. Diese werden physikalisch, datenbasiert (Maschinelles Lernen), oder hybrid modelliert. Das Training der datenbasierten Modelle beruht auf standardisierten Manövern, welche als Teil der Inbetriebnahme gefahren werden. Die virtuelle Prüfstandsumgebung ermöglicht eine Verkürzung der Inbetriebnahmezeit des Prüfstands, optimierte Parametersätze und bildet die Grundlage für die virtuelle Weiterentwicklung des Fahrreglers.Item Open Access Automated and virtual optimization of race-track simulation parameters on the power-train test bench(2023) Schilling, Jannes; Wilmsen, Jan-Michael; Reuss, Hans-Christian; Schmidt, Henrik; Prokop, GüntherThis paper focuses on powertrain test benches (PTB) in motorsports applications. In this case, a real powertrain is coupled with a virtual environment on the PTB to emulate mechanical loads experienced during racetrack driving. We utilize a Digital Twin of the PTB (a combination of the PTBs’ virtual environment, a powertrain model and a testbed model) to reduce setup time and allow offline virtual environment parameterization. The simulation models of the virtual environment may not always provide accurate representations due to unknown parameters or simplifications made to meet real-time requirements. Consequently, there are discrepancies between PTB and vehicle measurements. This paper aims to minimize such differences with a novel parame-ter optimization method.Item Open Access Development of a low-expansion and low-shrinkage thermoset injection moulding compound tailored to laminated electrical sheets(2024) Braunbeck, Florian; Schönl, Florian; Preußler, Timo; Reuss, Hans-Christian; Demleitner, Martin; Ruckdäschel, Holger; Berendes, PhilippThis study presents a thermoset moulding compound designed for electrical machines with high power densities. The compound reduces residual stresses induced by the difference in thermal expansion during use and by shrinkage in the compound during the manufacturing process. To reduce the internal stresses in the compound, in the electrical sheet lamination and at their interface, first the moulding’s coefficient of thermal expansion (CTE) must match that of the lamination because the CTE of the electrical sheets cannot be altered. Second, the shrinkage of the compound needs to be minimized because the moulding compound is injected around a prefabricated electrical sheet lamination. This provides greater freedom in the design of an electric motor or generator, especially if the thermoset needs to be directly bonded to the electrical sheet. The basic suitability of the material for the injection moulding process was iteratively optimised and confirmed by spiral flow tests. Due to the reduction of the residual stresses, the compound enables efficient cooling solutions for electrical machines with high power densities. This innovative compound can have a significant impact on electric propulsion systems across industries that use laminated electrical sheets.Item Open Access Concept development for bearing fault detection on water-cooled electric machines using infrared(2025) Schamberger, Stephanie; Brandl, Lukas; Reuss, Hans-Christian; Wagner, AlfonsElectric machines (EMs) of electrified vehicle drivetrains can be tested on drivetrain test benches at an early stage of development. In order to protect the EMs from premature damage or failure during testing, monitoring their thermal condition is important. Due to the package requirements of compact and powerful EMs with high-speed requirements and high-power densities, the heat build-up inside the motor during operation is particularly high. For this reason, fluid cooling with heat exchangers is increasingly being used in EMs. The EMs analysed in this work are water-cooled by a cooling jacket. This influences the heat flow inside the machine through heat transfer mechanisms, making it difficult to detect damage to the EMs. This paper presents a novel method for non-destructive and non-contact thermal condition monitoring of water-cooled EMs on drivetrain test benches using thermography. In an experimental setup, infrared images of an intact water-cooled EM are taken. A bearing of the EM’s rotor is then damaged synthetically, and the experiment is repeated. The infrared images are then processed and analysed using appropriate software. The analysis of the infrared images shows that the heat propagation of the motor with bearing damage differs significantly from the heat propagation of the motor without bearing damage. This means that thermography opens up another method of condition monitoring for water-cooled EMs. The results of the investigation serve as a basis for future condition monitoring of water-cooled EMs on powertrain test benches using artificial intelligence (AI).