TY - JOUR A1 - Wilhelm, Gudrun A1 - Golla-Schindler, Ute A1 - Wöhrl, Katharina A1 - Geisbauer, Christian A1 - Cooke, Graham A1 - Bernthaler, Timo A1 - Schweiger, Hans-Georg A1 - Schneider, Gerhard T1 - Influence of Water on Aging Phenomena of Calendric Stored and Cycled Li-Ion Batteries JF - Nanoenergy Advances N2 - We examine the impact of water (160 ± 41 ppm of reference) on the anode, cathode, separator and electrolyte in two aging scenarios: calendric aging (60 °C, 80 days, charged state), resulting in a triggered current interrupt device (CID), and cycling 1680 times (charge/discharge with 1C, 2.75–4.2 V, 20 ± 2 °C), resulting in 24.5% residual capacity. We applied computer tomography (CT), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and secondary ion mass spectrometry (SIMS) to understand the capacity loss. The aged NMC/LCO–graphite cells were compared to a reference cell in pristine state. Both aging scenarios showed (a) thick depositions on the anode and cathode consisting mainly of oxygen, fluorine and phosphorous, (b) reduced separator pore sizes, (c) the deposition of Mn, Co and Ni on top of the anode and (d) the decomposition of the conductive salt LiPF6 accompanied by HF formation and a loss of active lithium. Calendric aging consumes the water content and additionally leads to (e) the decomposition of the organic solvent followed by CO2 gas formation. Cyclic aging increases the water content and additionally results in (f) the consumption of the additive fluoroethylene carbonate (FEC). These findings show how water affects aging phenomena and results in a capacity decrease in the cell. UR - https://doi.org/10.3390/nanoenergyadv4020011 Y1 - 2024 UR - https://doi.org/10.3390/nanoenergyadv4020011 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-48606 SN - 2673-706X VL - 4 IS - 2 SP - 174 EP - 195 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bauder, Maximilian A1 - Festag, Andreas A1 - Kubjatko, Tibor A1 - Schweiger, Hans-Georg T1 - Data accuracy in Vehicle-to-X cooperative awareness messages: An experimental study for the first commercial deployment of C-ITS in Europe JF - Vehicular Communications N2 - Cooperative Intelligent Transportation Systems have achieved a mature technology stage and are in an early phase of mass deployment in Europe. Relying on Vehicle-to-X communication, these systems were primarily developed to improve traffic safety, efficiency, and driving comfort. However, they also offer great opportunities for other use cases. One of them is forensic accident analysis, where the received data provide details about the status of other traffic participants, give insights into the accident scenario, and therefore help in understanding accident causes. A high accuracy of the sent information is essential: For safety use cases, such as traffic jam warning, a poor accuracy of the data may result in wrong driver information, undermine the usability of the system and even create new safety risks. For accident analysis, a low accuracy may prevent the correct reconstruction of an accident. This paper presents an experimental study of the first generation of Cooperative Intelligent Transportation Systems in Europe. The results indicate a high accuracy for most of the data fields in the Vehicle-to-X messages, namely speed, acceleration, heading and yaw rate information, which meet the accuracy requirements for safety use cases and accident analysis. In contrast, the position data, which are also carried in the messages, have larger errors. Specifically, we observed that the lateral position still has an acceptable accuracy. The error of the longitudinal position is larger and may compromise safety use cases with high accuracy requirements. Even with limited accuracy, the data provide a high value for the accident analysis. Since we also found that the accuracy of the data increases for newer vehicle models, we presume that Vehicle-to-X data have the potential for exact accident reconstruction. UR - https://doi.org/10.1016/j.vehcom.2024.100744 Y1 - 2024 UR - https://doi.org/10.1016/j.vehcom.2024.100744 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-48060 SN - 2214-2096 VL - 2024 IS - 47 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Langer, Robin A1 - Michl, Marco A1 - Paula, Daniel A1 - Hof, Hans-Joachim A1 - Schweiger, Hans-Georg T1 - Security analysis of an Event Data Recorder system according to the HEAVENS model T2 - Proceedings of the 30th Annual Congress of the EVU Y1 - 2022 PB - EVU CY - Berlin ER - TY - CHAP A1 - Bauder, Maximilian A1 - Paula, Daniel A1 - Fehringer, Thomas A1 - Kubjatko, Tibor A1 - Schweiger, Hans-Georg T1 - Performance of Automatic Speed Sign Recognition and Adaptive Speed Adjustment of Real Vehicles on German Roads T2 - Proceedings of the 31st Annual Congress of the EVU KW - Accident Analysis; Accident Reconstruction; Traffic Sign Recognition; Intelligent Adaptive Cruise Control; Real Operating Investigation; Fundamental Data Y1 - 2023 SP - 242 EP - 252 PB - EVU CY - Berlin ER - TY - CHAP A1 - Bauder, Maximilian A1 - Kubjatko, Tibor A1 - Schweiger, Hans-Georg T1 - Development of an Accident Reconstruction Method Using Cooperative Awareness Message Data T2 - Proceedings of the 32nd Annual Congress of the EVU KW - Accident Reconstruction KW - Vehicle-2-X Communication KW - Cooperative Awareness Message Y1 - 2024 SP - 376 EP - 390 PB - EVU CY - Berlin ER - TY - JOUR A1 - Paula, Daniel A1 - Bauder, Maximilian A1 - Pfeilschifter, Claus A1 - Petermeier, Franziska A1 - Kubjatko, Tibor A1 - Böhm, Klaus A1 - Riener, Andreas A1 - Schweiger, Hans-Georg T1 - Impact of Partially Automated Driving Functions on Forensic Accident Reconstruction: A Simulator Study on Driver Reaction Behavior in the Event of a Malfunctioning System Behavior JF - Sensors N2 - Partially automated driving functions (SAE Level 2) can control a vehicle’s longitudinal and lateral movements. However, taking over the driving task involves automation risks that the driver must manage. In severe accidents, the driver’s ability to avoid a collision must be assessed, considering their expected reaction behavior. The primary goal of this study is to generate essential data on driver reaction behavior in case of malfunctions in partially automated driving functions for use in legal affairs. A simulator study with two scenarios involving 32 subjects was conducted for this purpose. The first scenario investigated driver reactions to system limitations during cornering. The results show that none of the subjects could avoid leaving their lane and moving into the oncoming lane and, therefore, could not control the situation safely. Due to partial automation, we could also identify a new part of the reaction time, the hands-on time, which leads to increased steering reaction times of 1.18 to 1.74 s. The second scenario examined driver responses to phantom braking caused by AEBS. We found that 25 of the 32 subjects could not override the phantom braking by pressing the accelerator pedal, although 16 subjects were informed about the system analog to the actual vehicle manuals. Overall, the study suggests that the current legal perspective on vehicle control and the expected driver reaction behavior for accident avoidance should be reconsidered. UR - https://doi.org/10.3390/s23249785 Y1 - 2023 UR - https://doi.org/10.3390/s23249785 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-42766 SN - 1424-8220 VL - 23 IS - 24 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bauder, Maximilian A1 - Langer, Robin A1 - Kubjatko, Tibor A1 - Schweiger, Hans-Georg T1 - Post-Processing Kalman Filter Application for Improving Cooperative Awareness Messages’ Position Data Accuracy JF - Sensors N2 - Cooperative intelligent transportation systems continuously send self-referenced data about their current status in the Cooperative Awareness Message (CAM). Each CAM contains the current position of the vehicle based on GPS accuracy, which can have inaccuracies in the meter range. However, a high accuracy of the position data is crucial for many applications, such as electronic toll collection or the reconstruction of traffic accidents. Kalman filters are already frequently used today to increase the accuracy of position data. The problem with applying the Kalman filter to the position data within the Cooperative Awareness Message is the low temporal resolution (max. 10 Hz) and the non-equidistant time steps between the messages. In addition, the filter can only be applied to the data retrospectively. To solve these problems, an Extended Kalman Filter and an Unscented Kalman Filter were designed and investigated in this work. The Kalman filters were implemented with two kinematic models. Subsequently, driving tests were conducted with two V2X vehicles to investigate and compare the influence on the accuracy of the position data. To address the problem of non-equidistant time steps, an iterative adjustment of the Process Noise Covariance Matrix Qand the introduction of additional interpolation points to equidistance the received messages were investigated. The results show that without one of these approaches, it is impossible to design a generally valid filter to improve the position accuracy of the CAM position data retrospectively. The introduction of interpolation points did not lead to a significant improvement in the results. With the Qmatrix adaptation, an Unscented Kalman Filter could be created that improves the longitudinal position accuracy of the two vehicles under investigation by up to 80% (0.54 m) and the lateral position accuracy by up to 72% (0.18 m). The work thus contributes to improving the positioning accuracy of CAM data for applications that receive only these data retrospectively. UR - https://doi.org/10.3390/s24247892 Y1 - 2024 UR - https://doi.org/10.3390/s24247892 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-55492 SN - 1424-8220 VL - 24 IS - 24 PB - MDPI CY - Basel ER - TY - CHAP A1 - Koch, Daniel A1 - Stein, Murillo A1 - de Abreu, Samuel Luna A1 - Diel, Sergej A1 - Schweiger, Hans-Georg T1 - Characterization and modeling of the swelling behavior of a LiFePO4 pouch cell in multiple operating conditions T2 - 2024 IEEE Vehicle Power and Propulsion Conference (VPPC), Proceedings UR - https://doi.org/10.1109/VPPC63154.2024.10755252 Y1 - 2024 UR - https://doi.org/10.1109/VPPC63154.2024.10755252 SN - 979-8-3315-4160-6 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Langer, Robin A1 - Bauder, Maximilian A1 - Moghariya, Ghanshyam Tukarambhai A1 - Eckert, Michael Clemens Georg A1 - Kubjatko, Tibor A1 - Schweiger, Hans-Georg T1 - Testing and Validation of the Vehicle Front Camera Verification Method Using External Stimulation JF - Sensors N2 - The perception of the vehicle’s environment is crucial for automated vehicles. Therefore, environmental sensors’ reliability and correct functioning are becoming increasingly important. Current vehicle inspections and self-diagnostics must be adapted to ensure the correct functioning of environmental sensors throughout the vehicle’s lifetime. There are several promising approaches for developing new test methods for vehicle environmental sensors, one of which has already been developed in our previous work. A method for testing vehicle front cameras was developed. In this work, the method is improved and applied again. Various test vehicles, including the Tesla Model 3, Volkswagen ID.3, and Volkswagen T-Cross, are stimulated by simulating driving scenarios. The stimulation is carried out via a tablet positioned before the camera. The high beam assist is used to evaluate the vehicle’s reaction. It was observed whether the vehicle switched from high to low beam as expected in response to the stimulation. Although no general statement can be made, the principle of stimulation works. A vehicle reaction can be successfully induced using this method. In further test series, the influence of display brightness is examined for the first time in this work. The results show that the display brightness significantly influences the test procedure. In addition, the method is validated by stimulation with colored images. It is shown that no complex traffic simulation is necessary to trigger a vehicle reaction. In the following validation approach, the CAN data of the Tesla Model 3 is analyzed during the tests. Here, too, the assumption that the vehicle reaction is based solely on the detected brightness instead of identifying road users is confirmed. The final validation approach examines the method’s applicability to other vehicles and high beam assist technologies. Although the method could not be used on the Volkswagen T-Cross due to a fault detected by the vehicle’s self-diagnosis, it worked well on the Volkswagen ID.3. This vehicle has a dynamic light assist in which individual segments of the high beam are dimmed during stimulation. Although the method developed to stimulate vehicle front cameras is promising, the specific factors that trigger the vehicle responses remain to be seen. This uncertainty suggests that further research is needed better to understand the interaction of stimulation and sensor detection. UR - https://doi.org/10.3390/s24248166 Y1 - 2024 UR - https://doi.org/10.3390/s24248166 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-56097 SN - 1424-8220 VL - 24 IS - 24 PB - MDPI CY - Basel ER - TY - JOUR A1 - Nebl, Christoph A1 - Kotzur, Frank-Oliver A1 - Koch, Daniel A1 - Schweiger, Hans-Georg T1 - Prediction of constant power delivery of lithium-ion cells at high loads JF - Journal of Energy Storage N2 - Available energy and available capacity are key factors for dimensioning batteries. Discharge duration of a battery and its dependency on discharge current amplitude are well described by Peukert’s law from low to medium current ranges. Other equations describe this dependency up to very high current rates, including the currents occurring during a short circuit. It is not current and capacity, but energy and power which are the key parameters for dimensioning battery systems. Thus, the available power of battery cells, vs. the discharge duration was investigated from low to high constant power discharge loads. Based on the results of these experiments, a correlation of the maximum discharge duration for low to medium discharge power pulses, similar to the Peukert’s equation was found. Additionally, a new equation is proposed, describing the power range from low to very high discharge power rates. The result of this work simplifies the design of battery systems, its electromechanical components, as well as improves the prediction of available boost power cost-effective way e.g. for hybrid electric vehicles. UR - https://doi.org/10.1016/j.est.2020.101552 KW - Constant power discharge KW - Lithium-ion batteries KW - Peukert equation KW - High load amplitudes KW - Constant power prediction KW - Discharge power Y1 - 2020 UR - https://doi.org/10.1016/j.est.2020.101552 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-9239 SN - 2352-1538 VL - 2020 IS - 30 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Gregor, Markus A1 - Bauder, Maximilian A1 - Kirsten Vidal de Oliveira, Aline A1 - Mast, Pascal A1 - Rüther, Ricardo A1 - Schweiger, Hans-Georg T1 - Approaches for Lifetime Prediction of Vehicle Traction Battery Systems During a Technical Inspection: A Systematic Review JF - World Electric Vehicle Journal N2 - Creating trust in society for new technologies, such as a new types of powertrains, and making them marketable requires transparent, neutral, and independent technical verification. This is crucial for the acceptance and success of electrified vehicles in the used car markets. A key component of electric vehicles is the traction battery, whose current and future condition, particularly regarding aging, determines its residual value and safe operation. This review aims to identify and evaluate methods for predicting the lifetime of onboard traction batteries, focusing on their applicability in technical inspections. A systematic literature and patent review was conducted using targeted keywords, yielding 22 patents and 633 publications. From these, 150 distinct lifetime prediction methods were extracted and categorized into a four-level mind map. These methods are summarized, cited, and structured in detailed tables. The relationships between approaches are explained to clarify the current research landscape. Long Short-Term Memory, Convolutional Neural Networks, and Particle Filters were identified as the most frequently used techniques. However, no methods were found suitable for predicting the lifetime of traction batteries during technical vehicle inspections, which operate under short test durations, limited data access, and diverse real-world operating conditions. Most studies focused on cell-level testing and did not address complete battery systems in operational vehicles. This gap highlights the need for applied research and the development of practical methods to support battery assessment in real-world conditions. Advancing this field is essential to foster confidence in battery systems and enable a sustainable transition to electromobility. UR - https://doi.org/10.3390/wevj17010003 Y1 - 2025 UR - https://doi.org/10.3390/wevj17010003 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:573-65631 SN - 2032-6653 VL - 17 IS - 1 PB - MDPI CY - Basel ER -