@article{GeisbauerWoehrlMittmannetal.2020, author = {Geisbauer, Christian and W{\"o}hrl, Katharina and Mittmann, Christoph and Schweiger, Hans-Georg}, title = {Review of Safety Aspects of Calendar Aged Lithium Ion Batteries}, volume = {167}, pages = {090523}, journal = {Journal of the Electrochemical Society}, number = {9}, publisher = {IOP Publishing}, address = {Bristol}, issn = {1945-7111}, doi = {https://doi.org/10.1149/1945-7111/ab89bf}, year = {2020}, abstract = {Nowadays, lithium ion batteries have found their place in a various field of portable applications. With the upcoming of electrically propelled vehicles, it is mandatory to guarantee a safe and predictable behavior during the whole lifetime and not only after manufacturing during performance tests. To gain a general overview of the abuse behavior, research on the topic of abusive tests on calendar-aged cells is being investigated, split up depending on the electrode composition and lined up against each other. It can be shown, that almost all abuse experiments have been performed with external heating tests in the past, still leaving research gaps that need to be filled.}, language = {en} } @article{BoehmKubjatkoPaulaetal.2020, author = {B{\"o}hm, Klaus and Kubjatko, Tibor and Paula, Daniel and Schweiger, Hans-Georg}, title = {New developments on EDR (Event Data Recorder) for automated vehicles}, volume = {10}, journal = {Open Engineering}, number = {1}, publisher = {De Gruyter}, address = {Berlin}, issn = {2391-5439}, doi = {https://doi.org/10.1515/eng-2020-0007}, pages = {140 -- 146}, year = {2020}, abstract = {With the upcoming new legislative rules in the EU on Event Data Recorder beginning 2022 the question is whether the discussed data base is sufficient for the needs of clarifying accidents involving automated vehicles. Based on the reconstruction of real accidents including vehicles with ADAS combined with specially designed crash tests a broader data base than US EDR regulation (NHTSA 49 CFR Part 563.7) is proposed. The working group AHEAD, to which the authors contribute, has already elaborated a data model that fits the needs of automated driving. The structure of this data model is shown. Moreover, the special benefits of storing internal video or photo feeds form the vehicle camera systems combined with object data is illustrated. When using a sophisticate 3D measurement method of the accident scene the videos or photos can also serve as a control instance for the stored vehicle data. The AHEAD Data Model enhanced with the storage of the video and photo feeds should be considered in the planned roadmap of the Informal Working Group (IWG) on EDR/ DSSAD (Data Storage System for Automated Driving) reporting to UNECE WP29. Also, a data access over the air using technology already applied in China for electric vehicles called Real Time Monitoring would allow a quantum leap in forensic accident reconstruction.}, language = {en} } @article{StegerNitscheArbesmeieretal.2020, author = {Steger, Fabian and Nitsche, Alexander and Arbesmeier, Alexander and Brade, Katja and Schweiger, Hans-Georg and Belski, Iouri}, title = {Teaching Battery Basics in Laboratories: Hands-On Versus Simulated Experiments}, volume = {63}, journal = {IEEE Transactions on Education}, number = {3}, publisher = {IEEE}, address = {Piscataway}, issn = {1557-9638}, doi = {https://doi.org/10.1109/TE.2020.2970554}, pages = {198 -- 208}, year = {2020}, abstract = {Contribution: Prior studies comparing the effectiveness of different laboratory learning modes do not allow one to draw a universally valid conclusion, as other influences are mixed with the learning modes. In order to contribute to the existing body of work and to add another piece to the puzzle, this article demonstrates an improved methodology to evaluate the effectiveness of computer-simulated laboratories in comparison to hands-on exercises using a battery basics practical course as a case study. Background: Computer-simulated experiments are becoming increasingly popular for conducting laboratory exercises in higher education and vocational training institutions. To ensure the consistent quality of laboratory learning, an accurate comparison between the results of simulated experiments and practical hands-on experiments is required. Intended Outcomes: In this article, the achievement of the following learning objectives were compared between the two laboratory modes: 1) comprehension of the most important parameters of battery cells and 2) knowledge on how these parameters can be determined using adequate experimental procedures. Application Design: To avoid interference of factors other than laboratory mode on the learning, laboratory instructions and experimental interfaces ensured identical execution of the experiments in the compared modes. Using a counterbalanced methodology, the two laboratory modes alternated by the session, while the experimental procedures remained constant regardless of the respective modes. Findings: Tests taken by the participants after conducting the laboratory experiments revealed that hands-on laboratories resulted in statistically significantly better student performance than simulated laboratories. This difference was even more pronounced for the participants that finished a vocational education and training program before the university studies.}, language = {en} } @article{KimStegerKotaketal.2019, author = {Kim, Woong-Ki and Steger, Fabian and Kotak, Bhavya and Knudsen, Peter V. R. and Girgsdies, Uwe and Schweiger, Hans-Georg}, title = {Water Condensation in Traction Battery Systems}, volume = {12}, pages = {1171}, journal = {Energies}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {https://doi.org/10.3390/en12061171}, year = {2019}, abstract = {Lithium-ion traction battery systems of hybrid and electric vehicles must have a high level of durability and reliability like all other components and systems of a vehicle. Battery systems get heated while in the application. To ensure the desired life span and performance, most systems are equipped with a cooling system. The changing environmental condition in daily use may cause water condensation in the housing of the battery system. In this study, three system designs were investigated, to compare different solutions to deal with pressure differences and condensation: (1) a sealed battery system, (2) an open system and (3) a battery system equipped with a pressure compensation element (PCE). These three designs were tested under two conditions: (a) in normal operation and (b) in a maximum humidity scenario. The amount of the condensation in the housing was determined through a change in relative humidity of air inside the housing. Through PCE and available spacing of the housing, moisture entered into the housing during the cooling process. While applying the test scenarios, the gradient-based drift of the moisture into the housing contributed maximum towards the condensation. Condensation occurred on the internal surface for all the three design variants.}, language = {en} } @article{NotomistaBotsch2017, author = {Notomista, Gennaro and Botsch, Michael}, title = {A Machine Learning Approach for the Segmentation of Driving Maneuvers and its Application in Autonomous Parking}, volume = {7}, journal = {Journal of Artificial Intelligence and Soft Computing Research (JAISCR)}, number = {4}, publisher = {De Gruyter Open}, address = {Warschau}, issn = {2449-6499}, doi = {https://doi.org/10.1515/jaiscr-2017-0017}, pages = {243 -- 255}, year = {2017}, abstract = {A classification system for the segmentation of driving maneuvers and its validation in autonomous parking using a small-scale vehicle are presented in this work. The classifiers are designed to detect points that are crucial for the path-planning task, thus enabling the implementation of efficient autonomous parking maneuvers. The training data set is generated by simulations using appropriate vehicle-dynamics models and the resulting classifiers are validated with the small-scale autonomous vehicle. To achieve both a high classification performance and a classification system that can be implemented on a microcontroller with limited computational resources, a two-stage design process is applied. In a first step an ensemble classifier, the Random Forest (RF) algorithm, is constructed and based on the RF-kernel a General Radial Basis Function (GRBF) classifier is generated. The GRBF-classifier is integrated into the small-scale autonomous vehicle leading to excellent performance in parallel-, cross- and oblique- parking maneuvers. The work shows that segmentation using classifies and open-loop control are an efficient approach in autonomous driving for the implementation of driving maneuvers.}, language = {en} } @article{SequeiraPatelAfrajetal.2020, author = {Sequeira, Gerald Joy and Patel, Akshay and Afraj, Shahabaz and Lugner, Robert and Brandmeier, Thomas}, title = {FEM-based methodology for crash severity estimation in frontal crash scenarios}, volume = {2020}, pages = {012019}, journal = {IOP Conference Series: Materials Science and Engineering}, number = {831}, publisher = {IOP}, address = {Bristol}, issn = {1757-899X}, doi = {https://doi.org/10.1088/1757-899X/831/1/012019}, year = {2020}, abstract = {With the technological development of forward-looking sensors, researchers are exploring their use not only for advanced driver assistance systems but also to gain important pre-crash information. Based on this pre-crash information, if the occupant motion inside the vehicle structure can be predicted for the oncoming crash scenario, then an optimal restraint strategy can be planned before the crash. This paper introduces a two-step FEM simulation based methodology for predicting the occupant severity in head-on crash scenarios. In the first step, we simulate the vehicle level model with different impact positions and relative approach angles. The results of these simulations, linear velocities in the longitudinal and lateral direction and angular velocities (roll, pitch, and yaw) during in-crash phase are the loading conditions for next simulation step (occupant level). This step simulates the motion of the driver in different crash scenarios. In this paper, we investigate the head, neck, and chest injury risks from vehicle-to-vehicle crash both traveling at 50 kilometers per hour. Prediction of the head injury criterion, identifying the cases where additional deployment of side-airbags and discussion of injury criteria with contour plots are the main outcome of this paper.}, language = {en} } @article{WeiglPonocny2020, author = {Weigl, Klemens and Ponocny, Ivo}, title = {Group sequential designs applied in psychological research}, volume = {16}, journal = {Methodology: European Journal of Research Methods for the Behavioral and Social Sciences}, number = {1}, publisher = {PsychOpen}, address = {Trier}, issn = {1614-2241}, doi = {https://doi.org/10.5964/meth.2811}, pages = {75 -- 91}, year = {2020}, abstract = {Psychological research is confronted with ever-increasing demands to save resources such as time and money while assuring high ethical standards. In medical and pharmaceutical research, group sequential designs have fundamentally changed traditional statistical testing approaches featuring only one analysis at the end of a single-stage study. They enable early stopping at an interim stage, after a group of observations, for efficacy or futility in case of an overwhelmingly large or small effect, respectively. Otherwise, the trial is continued to the next stage. On average over many studies time and money are saved and more ethical trials are facilitated by diminishing the risk of patients' exposure to inferior treatments. We provide an easy-to-use tutorial for psychological research replete with easily understandable figures highlighting the core idea of different group sequential designs, a workflow chart, an empirical real-world data set, and the annotated R code. Finally, we demonstrate the application of early stopping for efficacy.}, language = {en} } @inproceedings{deMeerWaedtRennochetal.2019, author = {de Meer, Jan and Waedt, Karl and Rennoch, Axel and Hof, Hans-Joachim}, title = {4th GI/ACM Workshop on standardization of I4.0 automation and control systems}, volume = {2019}, booktitle = {Lecture Notes in Informatics (LNI) - Proceedings}, number = {Volume P-295}, publisher = {Gesellschaft f{\"u}r Informatik}, address = {Bonn}, isbn = {978-3-88579-689-3}, issn = {1617-5468}, doi = {https://doi.org/10.18420/inf2019_ws27}, pages = {241 -- 242}, year = {2019}, language = {en} } @article{KundingerSofraRiener2020, author = {Kundinger, Thomas and Sofra, Nikoletta and Riener, Andreas}, title = {Assessment of the Potential of Wrist-Worn Wearable Sensors for Driver Drowsiness Detection}, volume = {20}, pages = {1029}, journal = {Sensors}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {https://doi.org/10.3390/s20041029}, year = {2020}, abstract = {Drowsy driving imposes a high safety risk. Current systems often use driving behavior parameters for driver drowsiness detection. The continuous driving automation reduces the availability of these parameters, therefore reducing the scope of such methods. Especially, techniques that include physiological measurements seem to be a promising alternative. However, in a dynamic environment such as driving, only non- or minimal intrusive methods are accepted, and vibrations from the roadbed could lead to degraded sensor technology. This work contributes to driver drowsiness detection with a machine learning approach applied solely to physiological data collected from a non-intrusive retrofittable system in the form of a wrist-worn wearable sensor. To check accuracy and feasibility, results are compared with reference data from a medical-grade ECG device. A user study with 30 participants in a high-fidelity driving simulator was conducted. Several machine learning algorithms for binary classification were applied in user-dependent and independent tests. Results provide evidence that the non-intrusive setting achieves a similar accuracy as compared to the medical-grade device, and high accuracies (>92\%) could be achieved, especially in a user-dependent scenario. The proposed approach offers new possibilities for human-machine interaction in a car and especially for driver state monitoring in the field of automated driving.}, language = {en} } @article{RienerJeon2019, author = {Riener, Andreas and Jeon, Myounghoon}, title = {Guest editors' introduction: multimodal technologies and interaction in the era of automated driving}, volume = {3}, pages = {41}, journal = {Multimodal Technologies and Interaction}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2414-4088}, doi = {https://doi.org/10.3390/mti3020041}, year = {2019}, language = {en} } @inproceedings{StegerNitscheMileyetal.2017, author = {Steger, Fabian and Nitsche, Alexander and Miley, Cayler and Schweiger, Hans-Georg and Belski, Iouri}, title = {Laboratory Learning: Hands-on versus Simulated Experiments}, booktitle = {Proceedings of the 28th Annual Conference of the Australasian Association for Engineering Education (AAEE 2017)}, editor = {Huda, Nazmul and Inglis, David and Tse, Nicholas and Town, Graham}, publisher = {Macquarie University}, address = {Sydney}, isbn = {978-0-646-98026-3}, url = {https://researchers.mq.edu.au/en/publications/proceedings-of-the-28th-annual-conference-of-the-australasian-ass}, pages = {940 -- 947}, year = {2017}, abstract = {CONTEXT Many universities and vocational training institutions conduct laboratories as simulated experiments. This is due to the costs and supervision needs to conduct hands-on labs safely. Numerous studies have presented mixed opinions on whether hands-on laboratory work is more conducive to learning than a simulated laboratory. Most of the studies put students from experimental and control groups in significantly different conditions. Therefore, it is hard to reach any definite conclusion regarding the influence of the learning mode onto the learning achievements. PURPOSE This study compares learning outcomes of student laboratory work in an energy storages course conducted in two different modes: first as a practical hands-on exercise and second using computer-based simulations. APPROACH In order to provide reliable insights, this study implements optimized research methodology to avoid any other effect (e.g. learning synchronicity/distance learning/instructions) on the learning outcome rather than the effect of the learning mode itself. The student laboratory experiments were created in a manner that they could be conducted in both modes in the same way and using a single set of instructions. To ensure a comparable group environment for the individual student, the students were arranged into two similar groups based on the student's practical experience. In this crossover study, the groups were taught the same topics by means of interchanging learning modes. RESULTS To evaluate the influence of each mode on student learning, short written tests regarding the previous experiment were conducted at the beginning of the subsequent laboratory session. 102 students have taken part in the study in two years. Overall learning results of hands-on experiments were slightly better than those of simulated laboratories (Cohen's d=0.25), the difference in performance was statistically significant (p<0.02). Through solicited feedback on each laboratory session, in hands-on mode more students expressed they have acquired new insights/comprehensions (76\% vs. 66\%, Cohen's d=0.23, small effect, p<0.07). CONCLUSIONS Following the strategy not to optimize the lessons individually to the learning mode, other influences on the learning outcome, which were usually mixed, were excluded. The students' subjective opinions show advantages of the hands-on mode. Based on the objective data, a weak, but significant outcome to better knowledge acquisition with hands-on laboratory experiments was achieved. This observation is against the trend of the literature in the last years towards better or equal learning with nontraditional labs. Some of the excluded factors might have a stronger influence on student learning than estimated previously. To get a clear view, the authors recommend isolated research.}, language = {en} } @inbook{KolbWechSchwabeetal.2020, author = {Kolb, Jan Christopher and Wech, Lothar and Schwabe, Martin and Ruzok, Christopher and Trost, Christoph}, title = {Technische Aspekte des automatisierten Fahrens am Projekt des autonomen Shuttlebusses in Bad Birnbach}, booktitle = {Autonome Shuttlebusse im {\"O}PNV}, editor = {Riener, Andreas and Appel, Alexandra and Dorner, Wolfgang and Huber, Thomas and Kolb, Jan Christopher and Wagner, Harry}, publisher = {Springer Vieweg}, address = {Berlin, Heidelberg}, isbn = {978-3-662-59405-6}, doi = {https://doi.org/10.1007/978-3-662-59406-3_5}, pages = {57 -- 91}, year = {2020}, abstract = {Die Entwickler von selbstfahrenden Fahrzeugen sind sich einig, dass es nach heutigem Stand der Technik {\"u}ber eine Milliarde Testkilometer bedarf, um ein autonom fahrendes Fahrzeug zu entwickeln. Daher {\"u}berrascht es nicht, dass der „autonome" Shuttlebus in Bad Birnbach lediglich als teilautomatisiert einzustufen ist. Dennoch ist das Projekt wertvoll, um Erkenntnisse f{\"u}r die Entwicklung von autonomen Fahrzeugen zu erlangen und deren Einsatz im {\"o}ffentlichen Personennahverkehr ({\"O}PNV) beurteilen zu k{\"o}nnen. Im vorliegenden Teilprojekt wurden innerhalb von vier Monaten {\"u}ber dreihundert Situationen dokumentiert, in denen die Fahrt unplanm{\"a}ßig unterbrochen wurde. Diese wurden anschließend ausgewertet und teilweise in Versuchen nachgestellt. Es hat sich gezeigt, dass der Shuttlebus im aktuellen Betriebsmodell unfallfrei fahren kann. Allerdings ist f{\"u}r das unfall- und unterbrechungsfreie Fahren der durch die Zulassungsauflagen vorgeschriebene Operator an Bord zwingend erforderlich. Dieser muss an verschiedenen Stellen der Strecke - inklusive der Haltestellen - die Weiterfahrt best{\"a}tigen, den Bus um Hindernisse lenken und bei einem drohenden Unfall eingreifen. Ohne Operator k{\"a}me es zur Kollision, da die Technik des Busses nicht alle kritischen Situationen erkennt. Der Bus kann im aktuellen Entwicklungsstand weder fahrerlos betrieben noch als zuverl{\"a}ssige Erg{\"a}nzung im {\"O}PNV eingesetzt werden. Der Bus stellt dennoch einen wichtigen Schritt in Richtung autonomen Fahrens dar, welches weiterhin im Rahmen zuk{\"u}nftiger Forschungs- und Entwicklungsprojekte vorangetrieben werden muss.}, language = {de} }