wbk

Ludwig Hausmann, M.Sc.

  • 76131 Karlsruhe
    Kaiserstraße 12

Ludwig Hausmann, M.Sc.

Area of Research:

  • Electric machine manufacturing

 

Projects:

 

Curriculum Vitae:

since 10/2018 Research Associate at the Institute of Production Science (wbk) at Karlsruhe Institute of Technology (KIT)
03 - 07/2017 Stay abroad at the amtc of Tongji University, Shanghai
10/2011 - 05/2018 Study of Mechanical Engineering at Karlsruhe Institute for Technology (KIT)

 

Publications

[ 1 ] Wirth, F.; Hausmann, L.; Halwas, M.; Hofmann, J.; Mayer, D.; Wößner, W. & Fleischer, J. (2019), "Optimierte Fertigung elektrischer Traktionsmotoren durch Technologien der Industrie 4.0". Future Mobility: automatisiert - vernetzt - elektrisch, eds. Technische Akademie Esslingen e.V., pp. 1.
Abstract
Striktere Emissionsvorgaben der Europäischen Union sowie die Endlichkeit fossiler Energieträger werden in der kommenden Dekade zu einem steigenden Absatz elektrifizierter Antriebsstränge führen. Damit die wachsende Nachfrage nach leistungsfähigen Traktionsmotoren sowie die hohen Anforderungen bezüglich Stückzahl und Qualität erfüllt werden können, müssen die innovativen aber vielmals noch unreifen Fertigungsprozesse für den industriellen Einsatz befähigt werden. Die Integration neuartiger Technologien der Industrie 4.0 in die Produktionskette stellt einen vielversprechenden Ansatz zur Lösung dieser Probleme dar. Durch eine digitale Prozessabsicherung können Wickelverfahren vor deren hardwareseitiger Erprobung bewertet und optimiert sowie Inbetriebnahmezeiten verkürzt werden. Zudem gestattet der digitale Zwilling sowohl eine prädiktive Prozesssteuerung als auch die isolierte Betrachtung von Einflussgrößen und darauf basierende Ableitung von Regelungsstrategien. Methoden des maschinellen Lernens und intelligente Algorithmen ermöglichen die Bewertung bislang unbekannter, produktseitiger Merkmale, wie den Lagenaufbau von Leitern in den Nuten von Blechpaketen, sowie die Einhaltung enger Qualitätsvorgaben durch angepasste Montagestrategien.

[ 2 ] Hausmann, L.; Wirth, F.; Franck, C.; Förderer, M.; Karrer, M.; Hofmann, J. & Fleischer, J. (2019), "Ausbildungsfabrik Statorfertigung", ZWF Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 10, pp. 621-626. 10.3139/104.112166
Abstract
The transformation process towards electric mobility results in new requirements for product development and production technology, which require the appropriate qualification of employees. In order to enable holistic further training, the wbk Institute for Production Engineering at KIT develops high-quality training concepts for the production of stators of electric traction drives by hairpin technology based on vocational pedagogical methods and integrates them into the overall concept of the training factory stator production.

[ 3 ] Hofmann, J.; Halwas, M.; Weinmann, H.; Wößner, W.; Schäfer, J.; Hausmann, L.; Wirth, F.; Storz, T. & Schild, L. (2019), "Transformationshub Elektromobilität in Baden-Württemberg" in Auf dem Weg zur Elektromobilität ? Wettbewerbsfaktor Produktionstechnik , eds. Fleischer, J.; Lanza, G.; Schulze, V. & , ., Shaker, Berlin, ISBN/ISSN: 978-3-8440-6953-2
Abstract
Die Automobilindustrie steckt in einem Transformationsprozess un-geahnten Ausmaßes und Ausgangs. Ob durch striktere europäische Abgasgrenzwerte, den Zwang lokaler Emissionsfreiheit oder den Druck des chinesischen Marktes beim Kampf um eine neue Vorherrschaftsrolle - die Gründe deutscher Automobilisten zur Elektrifizierung sind vielschichtig und die Folgen kaum abschätzbar. Die Frage, ob neue Antriebstechnologien in den Markt eingeführt wer-den, stellt sich mittlerweile kein Automobilhersteller mehr, stattdessen verbleibt die Frage nach dem ?wie?. Mit der diesjährigen wbk Herbsttagung ?Auf dem Weg zur Elektromobilität ? Wettbewerbsfaktor Produktionstechnik? wollen wir die vorhandenen Chancen im Bereich der Produktionstechnik für die Elektromobilität aufzeigen und einen Beitrag dazu leisten, dass diese auch genutzt werden. Hochkarätige Impulsvorträge aus Industrie und Forschung schaffen die Diskussionsbasis für einen Informationsaustausch zur Elektromobilität. Die wbk-Herbsttagung bietet dabei eine Plattform für den Dialog zwischen Politik, Anwendern, Produzenten, Anlagenbauern sowie dem wbk als Forschungspartner vor Ort.

[ 4 ] Halwas, M.; Sell-Le Blanc, F.; Jux, B.; Doppelbauer, M.; Wirth, F.; Hausmann, L.; Hofmann, J. & Fleischer, J. (2019), "Coherences Between Production Technology and Performance of Electric Traction Drives". 2019 9th International Electric Drives Production Conference (EDPC), eds. IEEE, pp. 1-9. 10.1109/EDPC48408.2019.9011889
Abstract
Coherences between production technology and performance of electric traction drives are published or based on experiential knowledge. The content of this paper shall represent an essential basis for intentions of improving future research and development purposes of production technologies for traction drives, but also of electric machine designs in general. The basic ambition of engineering a new manufacturing technology is to improve the performance of a product, taking several boundary conditions into account, like costs or cycle times. It has to be considered that the conflict area of production and performance are connected by physical characteristics, which are determined by the geometric and material compositions of the electric machine in this context. It is evident that the physical characteristics have a direct impact on the performance of electric machines. However, the production technology has a straight and unavoidable influence on the physical characteristic. An example for this is the slot fill factor, which is determined by the winding technology, but influences the performance of the machine significantly. First, known coherences between physical characteristics and performance of electric machines are considered. Therefore, an extensive summary of technical literature and publications at the current state of the art in science applications is used as a starting point. To give the best possible overview, a summary and visualization dependency matrix is created, in which the various elements of physical characteristic and the resulting performance of the electric machine are compared against each other. Next, the main influences of the different manufacturing processes on the characteristics of electric machines are presented, especially focusing on the winding technology. These contents are also transferred into the dependency matrix.

[ 5 ] Mayer, D.; Hausmann, L.; Maul, N.; Reinschmidt, L.; Hofmann, J. & Fleischer, J. (2019), "Systematic investigation of the grooving process and its influence on slot insulation of stators with hairpin technology". 9th International Electric Drives Production Conference (E|DPC) - Proceedings, IEEE, Piscataway, NJ, pp. 1. 10.1109/EDPC48408.2019.9011935
Abstract
Due to the increasing electrification of the automotive drive train, production systems for electric motors grow in importance. In order to produce the required quantities at reasonable costs there is a particular need for developing new stator production plants. A trend towards using shaped coils in stators, so called hairpins, is emerging as this technology promises great automation potentials as well as high copper fill factors. Due to the axial insertion of the hairpins into the lamination stack the requirements for the slot liner shape change in contrast to the widely used winding technologies. Thus, new slot liner shapes, such as ?B?-, ?O?- or ?S?-shapes, can be used. The shapes replace the previous ?U?- shaped slot liner as well as the slot cover. In order to maintain a high fill factor, the shapes have to fit closely to the lamination stack. For this purpose, the insulation paper must be grooved and then folded into the desired shape. To map the new slot liner shapes, the grooving process and its influence on slot insulation must be understood in detail. In this paper the grooving process and its effect on breakdown voltage of the slot liner are examined. First, an overview about different insulation materials for slot liners is given. Second, a test rig setup to adjust different depths and widths of grooving is introduced. Additionally, a further test rig setup for conducting breakdown voltage tests on slot liners is presented. Based on these test rigs, experiments are carried out to determine how the grooving process parameters affect the breakdown voltage of the slot liners. As a result of the investigation a characterization of the grooving process regarding the breakdown voltage for the examined insulation paper is presented.

[ 6 ] Halwas, M.; Hausmann, L.; Wirth, F.; Fleischer, J.; Jux, B. & Doppelbauer, M. (2020), "Influences of Design and Manufacturing on the Performance of Electric Traction Drives". 2020 International Conference on Electrical Machines (ICEM), eds. IEEE, 10.1109/ICEM49940.2020.9270899
Abstract
The transformation to electric mobility is a major challenge for automotive manufacturers and suppliers, as their research and development departments are mainly familiar with conventional combustion-based powertrains and the experience has grown over the last century, but electric machines and the corresponding technologies are often unknown. To meet these requirements, this paper is intended as a guideline for developers facing the new field of electric traction drives. First, the known winding technologies are resumed. Subsequently, the influences of design and manufacturing on the performance of electric traction drives are discussed, based on a previous literature research. Thereby, the focus of this paper is on state of the art winding technologies, traction drive designs and powertrains, so some simplifications are made for these cases of application.

[ 7 ] Mühlbeier, E.; Gönnheimer, P.; Hausmann, L. & Fleischer, J. (2020), "Value Stream Kinematics". Production at the leading edge of technology, eds. Behrens, B.; Brosius, A.; Hintze, W.; Ihlenfeldt, S. & Wulfsberg, J. P., Springer, Berlin, Heidelberg, pp. 409-418. 10.1007/978-3-662-62138-7_41
Abstract
The trend towards individualized products and the increasing demand for a greater variety of variants create new challenges for existing production environments and require a re-thinking of production. Established manufacturing systems that provide the desired flexibility are associated with significant productivity restrictions and are therefore unable to compete economically with production from rigid production lines. They are therefore often limited to serving niche markets. Consequently, an approach is needed that combines high productivity with high flexibility. For this purpose, this paper presents a new approach to manufacturing with an equally high productivity and flexibility, so-called value stream kinematics. The basic idea of value stream kinematics is to combine the advantages of specialized machines with the versatility of industrial robots. The vision behind this is to be able to realize entire value streams with uniform robot-like kinematics and no need for special machines.

[ 8 ] Hausmann, L.; Wirth, F. & Fleischer, J. (2021), "Opportunities of Model-Based Production-Oriented Design of Stators with Hairpin Winding". 10th International Electric Drives Production Conference (EDPC), eds. IEEE, Piscataway, NJ, pp. 1-8. 10.1109/EDPC51184.2020.9388186
Abstract
The hairpin technology is a promising and widely used production method that meets the growing demand for high productivity and quality in the manufacturing of electric drives caused by increasing sales of electric vehicles. In comparison to conventional winding technologies, the technology provides significant advantages regarding the ability for automation, the productivity as well as the attainable filling factors, but also exhibits weaknesses concerning the process reliability and manufacturing constraints, which limit important degrees of freedom in electric design. Within the process chain of stator manufacturing by hairpin technology, especially the manufacturing constraints of the multi-step shaping processes of hairpin coils as well as the twisting and subsequent welding processes of the open coil endings show a high interdependency with important design parameters such as wire dimensions, coil pitch, stator diameter and number of slots. However, the complex interactions can only be captured by experimental tests on machine prototypes, which often leads to numerous time- and resource-intensive adaptations of tool and machine. To enable a production-oriented, cost-efficient design of stators with hairpin winding, several process models are introduced within the scope of this paper that allow a consideration of manufacturing influences within early periods of electric drives development. For this purpose, numerical approaches of process modeling carried out in Abaqus FEA are presented for different types of tool-bound bending processes as well as the twisting process. Furthermore, a study on the influence of different wire dimensions is carried out using the examples of rotary draw bending and twisting processes. In addition, simplified mathematical models for minimizing the winding head size under consideration of manufacturing aspects are described. The proposed methodology of virtual process assessment by FE-based as well as simplified process models offers particular advantages in the early phase of product design.

[ 9 ] Fleischer, J.; Pfund, T.; Wirth, F.; Fraider, F.; Halwas, M.; Hausmann, L. & Wößner, W. (2021), "Agile Produktion elektrischer Traktionsmotoren als Antwort auf volatile Märkte und Technologien", ZWF Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 116, no. 3, pp. 128-132. 10.1515/zwf-2021-0025
Abstract
Elektrische Traktionsmotoren nehmen - unabhängig von der Art der Elektrifizierung - eine zentrale Rolle im Mobilitätswandel ein. Volatile Rahmenbedingungen, Märkte und Technologien führen jedoch dazu, dass das Investitionsrisiko in dem Stand der Technik entsprechende Produktionssysteme mit eingeschränkter Flexibilität als hoch einzustufen ist. Vor diesem Hintergrund soll im Forschungsvorhaben AgiloDrive durch die integrierte Entwicklung modularer Produkt- und Produktionsbaukästen eine nachfrageorientierte Wandlungsfähigkeit des Produktionssystems befähigt werden.

[ 10 ] Hausmann, L.; Waldhof, M.; Fischer, J.; Wößner, W.; Oliveira Flammer, M.; Heim, M.; Fleischer, J. & Parspour, N. (2021), "Review and Enhancements of Rotor Designs for High Speed Synchronous Reluctance Machines". IEEE, Piscataway, NJ, pp. 1-8. 10.1109/EDPC51184.2020.9388205
Abstract
Rare earth metals are particularly required as a basic component of permanent magnets in modern traction drives for electric vehicles. Due to the limited global resources of raw materials, the environmental impact of mining and the challenges of recycling, the development of resource-saving alternatives is an important research topic. One option is the use of a synchronous reluctance machine (SynRM), whose rotor does not require magnetic materials, aluminum or copper due to its operating principle. Besides the cost-effective manufacturing, the robust and resource-saving rotor design and high efficiency of SynRM, this machine type suffers from a low power factor, poor torque and power density and earlier power drop in the field weakening range in comparison to permanent-magnet synchronous motors. These disadvantages result from the fragile design of the rotor lamination stack and the resulting limited maximum permissible operating speed of current industrial motors, which are therefore not yet suitable for traction drive applications.This paper gives an overview of new rotor concepts and designs which aim to increase the maximum operation speed of SynRM by optimizing the structural design. Subsequently, a new rotor topology is discussed and evaluated, especially regarding its mechanic and electromagnetic properties as well as the suitability for series production.

[ 11 ] Fleischer, J.; Hausmann, L. & Wirth, F. (2021), "Production-oriented design of electric traction drives with hairpin winding". Procedia CIRP, eds. Lutters, E., Elsevier, pp. 169-174. 10.1016/j.procir.2021.05.080 [Titel anhand dieser DOI in Citavi-Projekt ?bernehmen]
Abstract
In recent years, the manufacturing of stators by hairpin technology has proven its ability to fulfill the requirements on quality, productivity and robustness of traction drive applications in automotive industry. However, the uncertainty and necessity of rapid product development despite fuzzy target systems still cause that processes, machines and equipment - as well as the electric design - are often in an imperfect prototype stage at the start of production ramp-up. Due to the complex interdependencies between the stator components in combination with a high sensitivity of the overall process reliability to minor adjustments of stator design features, possible production-related weaknesses in design are often recognized first in the prototype stage of the production system. In order to reduce the economic risk resulting from these volatile technological conditions, production-oriented design based on numerical simulation methods can be applied from the beginning of product development. Therefore, several techniques for numerical process modeling are presented in this paper as possibilities to consider manufacturing constraints in an early stage of product development. For this purpose, the influence of wire dimensions on the forming process of hairpin coils is investigated using the example of rotary bending as well as the twisting process of a full stator by finite element simulations. Furthermore, a numerical approach to investigate the influence of heat input during laser welding of hairpin coils on the required stripping length is introduced.

[ 12 ] Hausmann, L. & Fleischer, J. (2021), "Flexibles Twisten von Statoren mit Hairpin-Wicklung", wt Werkstattstechnik online, vol. 111, pp. 490-494. doi.org/10.37544/1436-4980-2021-07-08
Abstract
Um wirtschaftlich auf die volatilen Marktanforderungen der Elektromobilität reagieren zu können, muss der Maschinen- und Anlagenbau den Automobilherstellern stückzahl- und variantenflexible Produktionslösungen bereitstellen. Im Kontext der Fertigung von Statoren mit Hairpin-Wicklung sind diesbezüglich die werkzeuggebundenen Prozessschritte zur Hairpin-Formgebung sowie zum Twisten der offenen Spulenenden zu fokussieren. Eine Perspektive für das flexible Twisten bis hin zur Losgröße-1 stellt ein neuer Ansatz mittels kinematischer Prozessführung dar.