@inproceedings{57185,
  author       = {{Reiling, Fabian and Henke, Christian and Hunstig, Matthias and Gröger, Stefan and Trächtler, Ansgar}},
  booktitle    = {{2024 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}},
  publisher    = {{IEEE}},
  title        = {{{Batch constrained multi-objective Bayesian optimization using the example of ultrasonic wire bonding}}},
  doi          = {{10.1109/aim55361.2024.10637123}},
  year         = {{2024}},
}

@inproceedings{57188,
  author       = {{Stieren, Stephan and Werner, Achim and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{2024 IEEE Conference on Technologies for Sustainability (SusTech)}},
  publisher    = {{IEEE}},
  title        = {{{A comprehensive test infrastructure for the evaluation of energy management systems of the household and grid level}}},
  doi          = {{10.1109/sustech60925.2024.10553455}},
  year         = {{2024}},
}

@inproceedings{57187,
  author       = {{Stieren, Stephan and Lenger, Luca and Kliem, Moritz and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{2024 IEEE International Systems Conference (SysCon)}},
  publisher    = {{IEEE}},
  title        = {{{Development of digital business models for holistic energy management on device, home and grid level}}},
  doi          = {{10.1109/syscon61195.2024.10553440}},
  year         = {{2024}},
}

@inproceedings{57186,
  author       = {{Schmidt, Robin and Schütz, Stefan and Prinz, Sebastian and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{Proceedings of the 4th IFSA Winter Conference on Automation, Robotics and Communications for Industry 4.0/5.0 (ARCI 2024)}},
  title        = {{{Optimizing Welding Efficiency: A First Approach for an Automated Mobile Welding Robot}}},
  year         = {{2024}},
}

@article{57176,
  abstract     = {{Incremental nonlinear dynamic inversion (INDI) is a widely used approach to controlling UAVs with highly nonlinear dynamics. One key element of INDI-based controllers is the control allocation realizing pseudo controls using available actuators. However, the tracking of commanded pseudo controls is not the only objective considered during control allocation. Since the approach only works locally due to linearization and the solution is often ambiguous, additional aspects like control efforts or penalizing the deviation of certain states must be considered. Conducting the control allocation by solving a quadratic program this results in a considerable number of weighting parameters, which must be tuned during control design. Currently, this is conducted manually and is therefore time consuming. An automated approach for tuning these parameters is therefore highly beneficial. Thus, this paper presents and evaluates a model-based approach automatically tuning the control allocation parameters of a tiltrotor VTOL using an optimization algorithm. This optimization algorithm searches for optimal parameters minimizing a cost functional that reflects the design target. This cost functional is calculated based on a test mission for the VTOL which is conducted within a simulation environment. The test mission represents the common operating range of the VTOL. The simulation environment consists of an aircraft model as well as a model of the INDI-based controller which is dependent on the control allocation parameters. On this basis, model-based optimization is conducted and the optimal parameters are identified. Finally, successful real-world tests on a 4-degrees-of-freedom testbench using the identified parameters are presented. Since the control allocation parameters can significantly influence the aircraft’s stability, the 4-DOF testbench for the aircraft is required for rapid validation of the parameters at a minimum amount of risk.}},
  author       = {{Henkenjohann, Mark and Nolte, Udo and Sion, Fabian and Henke, Christian and Trächtler, Ansgar}},
  issn         = {{2076-0825}},
  journal      = {{Actuators}},
  number       = {{5}},
  publisher    = {{MDPI AG}},
  title        = {{{Parameter Tuning Approach for Incremental Nonlinear Dynamic Inversion-Based Flight Controllers}}},
  doi          = {{10.3390/act13050187}},
  volume       = {{13}},
  year         = {{2024}},
}

@inproceedings{57173,
  abstract     = {{Manufacturing processes benefit from property control enabling reproducibility, application oriented outcomes, and efficient part production. In reverse flow forming, state of the art practices focus primarily on geometry control, neglecting property control. Given the intricacies of the process involving the interaction of tool and machine behavior, process parameters, properties of semi finished products and temperatures, incorporating process control becomes an imperative for producing components with predefined properties. The property controlled within this reverse flow forming process is the local α’ martensite content. Therefore, process strategies to actively influence the α’ martensite content must be implemented. In this study seamless AISI 304L steel tubes are used, where α’ martensite formation is strain  and/or temperature induced through phase transformation within the process. This paper presents innovative process strategies, methods, and specially developed mechanical and thermal actuator systems to locally increase or suppress the α’ martensite content. The use and implementation of these approaches and tools allows the creation of unique optically invisible microstructure profiles containing 3D gradings, implying a radial grading of α’ martensite. The locally implemented α’ martensite, forming these 3D gradings, offers potential applications for functional or sensory purposes. This paper extends beyond theoretical concepts, providing tangible component outcomes.}},
  author       = {{Arian, Bahman and Homberg, Werner and Kersting, Lukas and Trächtler, Ansgar and Rozo Vasquez, Julian and Walther, Frank}},
  booktitle    = {{Materials Research Proceedings}},
  issn         = {{2474-395X}},
  publisher    = {{Materials Research Forum LLC}},
  title        = {{{α’-martensite grading techniques in reverse flow forming of AISI 304L}}},
  doi          = {{10.21741/9781644903254-76}},
  volume       = {{44}},
  year         = {{2024}},
}

@inproceedings{57174,
  abstract     = {{Increasing the sustainability and resource efficiency of forming processes is one of today's major goals. High-strength wire materials are usually available as strip material and are subjected to a downstream forming process such as punch-bending to produce parts for the electronics industry, for example. During the manufacturing process of the semi-finished product, residual stresses and plastic deformations are introduced into the wire by rolling and drawing processes. Straightening machines are used in the production lines to compensate for these. To increase the sustainability of these production lines, the straightening process is an essential step. Before the continuous manufacturing process starts, the straightening process must be set up and the optimal roller positions must be found. Once the process is set up, the roller position settings are usually not changed. Due to missing measurement systems for the straightening quality, it is not possible to dynamically adjust the positions of the straightening rollers to variations in the material properties. This leads to deviations in the dimensional accuracy of the components to be produced and thus to an increase in the rejection rate in the manufacturing processes. To reduce the rejection rate, a novel control system for a continuous feedback control of a straightening process is presented in this paper. This leads to a reduction of the rejection rate and unnecessary preforming operations in wire straightening process. The result is an increasing sustainability and efficiency of these production process.}},
  author       = {{Bathelt, Lukas and Djakow, Eugen and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{Materials Research Proceedings}},
  issn         = {{2474-395X}},
  publisher    = {{Materials Research Forum LLC}},
  title        = {{{Innovative control system for straightening machines using sensor information from downstream processes}}},
  doi          = {{10.21741/9781644903131-308}},
  volume       = {{41}},
  year         = {{2024}},
}

@inproceedings{57178,
  abstract     = {{The incremental flow forming process is currently enhanced in research context by special closed-loop property control concepts to increase the productivity and to control the product properties making invisible property structures like a magnetic barcode possible. However, it is preferred to establish property control concepts on single roller machines instead of conventional machines with three roller actuation due to the better machine accessibility. For those single roller machines, rather poor surface qualities of flow formed workpieces were observed in the past especially for hydraulic actuators. Thus, a new actuator closed-loop position control concept is developed in this paper using model-based control design methods and taking the flow forming forces as a load into account. The novel closed-loop control is validated during workpiece production at the actual single roller flow forming machine. An analysis of the manufactured workpieces show that the surface quality is significantly enhanced by the new control to a roughness level almost similar to conventional three roller flow forming. Thus, a sincere added value to the flow forming process is offered by the novel actuator closed-loop position control.}},
  author       = {{Kersting, Lukas and Sander, Sebastian and Arian, Bahman and Rozo Vasquez, Julian and Trächtler, Ansgar and Homberg, Werner and Walther, Frank}},
  booktitle    = {{Materials Research Proceedings}},
  issn         = {{2474-395X}},
  publisher    = {{Materials Research Forum LLC}},
  title        = {{{Improving the flow forming process by a novel closed-loop control}}},
  doi          = {{10.21741/9781644903131-158}},
  volume       = {{41}},
  year         = {{2024}},
}

@inproceedings{57183,
  abstract     = {{In multi-stage bending and straightening operations cross-stage and quantity-dependent effects crucially affect the quality of the end product. Using punch-bending units in combination with a mechatronic straightening device can improve the accuracy and repeatability of product features remarkably well. In this work a concept for an innovative hybrid model of a roll straightener in a multi-stage straightening and multi-stage bending process is proposed. This model combines data-driven elements with expert knowledge and aims to minimise residual errors of the roll straightener to reliably decrease the risk of disadvantageous cross-stage and quantity-dependent effects on a subsequent punch-bending process.}},
  author       = {{Peters, Henning and Djakow, Eugen and Rostek, Tim and Mazur, Andreas and Trächtler, Ansgar and Homberg, Werner and Hammer, Barbara}},
  booktitle    = {{Materials Research Proceedings}},
  issn         = {{2474-395X}},
  publisher    = {{Materials Research Forum LLC}},
  title        = {{{Novel approach for data-driven modelling of multi-stage straightening and bending processes}}},
  doi          = {{10.21741/9781644903131-252}},
  volume       = {{41}},
  year         = {{2024}},
}

@inproceedings{57171,
  abstract     = {{In manufacturing, property control ensures efficient part production. However, in reverse flow forming, current practices focus on geometry control rather than property control. To address the complexity of the process and tool machine interaction, process control is crucial for defined component properties. This study focuses on controlling local α’ martensite content in reverse flow forming of seamless AISI 304L steel tubes. Strategies and systems are presented to influence α’ martensite content, creating unique microstructure profiles for 1D  and 2D Gradings, with tangible component outcomes.}},
  author       = {{Arian, Bahman and Homberg, Werner and Kersting, Lukas and Trächtler, Ansgar and Rozo Vasquez, Julian and Walther, Frank}},
  booktitle    = {{Materials Research Proceedings}},
  issn         = {{2474-395X}},
  publisher    = {{Materials Research Forum LLC}},
  title        = {{{Thermomechanical reverse flow forming of AISI 304L}}},
  doi          = {{10.21741/9781644903131-151}},
  volume       = {{41}},
  year         = {{2024}},
}

@inproceedings{57177,
  author       = {{Jahneke, Julien and Nolte, Udo and Henkenjohann, Mark and Seidenberg, Tobias and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{2024 IEEE Aerospace Conference}},
  publisher    = {{IEEE}},
  title        = {{{Development and Implementation of a Modular Interface for a DroneCAN Communication Bus}}},
  doi          = {{10.1109/aero58975.2024.10521247}},
  year         = {{2024}},
}

@inproceedings{57180,
  author       = {{Lenz, Cederic and Bause, Maximilian and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{2024 International Conference on Advanced Robotics and Mechatronics (ICARM)}},
  publisher    = {{IEEE}},
  title        = {{{Boosting Low Data PINN Robustness with Transfer Learning*}}},
  doi          = {{10.1109/icarm62033.2024.10715896}},
  year         = {{2024}},
}

@inproceedings{57181,
  author       = {{Lenz, Cederic and Bause, Maximilian and Reiling, Fabian and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{2024 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}},
  publisher    = {{IEEE}},
  title        = {{{Contextual Anomaly Detection in Hot Forming Production Line using PINN Architecture}}},
  doi          = {{10.1109/aim55361.2024.10637234}},
  year         = {{2024}},
}

@article{57893,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Control engineering applications usually require a model that accurately represents the dynamics of the system. In addition to classical physical modeling, powerful data‐driven approaches are gaining popularity. However, the resulting models may not be ideal for control design due to their black‐box structure, which inherently limits interpretability. Formulating the system dynamics in port‐Hamiltonian form is highly beneficial, as its valuable property of passivity enables the straightforward design of globally stable controllers while ensuring physical interpretability. In a recently published article, we presented a method for data‐driven inference of port‐Hamiltonian models for complex mechatronic systems, requiring only fundamental physical prior knowledge. The resulting models accurately represent the nonlinear dynamics of the considered systems and are physically interpretable. In this contribution, we advance our previous work by including two key elements. Firstly, we demonstrate the application of the above described data‐driven PCHD models for controller design. Preserving the port‐Hamiltonian form in the closed loop not only guarantees global stability and robustness but also ensures desired speed and damping characteristics. Since control systems based on output measurements, which are continuously measured during operation due to the feedback structure, we secondly aim to use this data. Thus, we augment the existing modeling strategy with an intelligent adaptation approach to address uncertainties and (un)predictable system changes in mechatronic systems throughout their lifecycle, such as the installation of new components, wear, or temperature fluctuations during operation. Our proposed algorithm for recursively calculated data‐driven port‐Hamiltonian models utilizes a least‐squares approach with extensions such as automatically adjusting the forgetting factor and controlling the covariance matrix trace. We demonstrate the results through model‐based application on an academic example and experimental validation on a test bench.</jats:p>}},
  author       = {{Junker, Annika and Timmermann, Julia and Trächtler, Ansgar}},
  issn         = {{1617-7061}},
  journal      = {{PAMM}},
  number       = {{1}},
  publisher    = {{Wiley}},
  title        = {{{Adaptive Data‐Driven Models in Port‐Hamiltonian Form for Control Design}}},
  doi          = {{10.1002/pamm.202400154}},
  volume       = {{25}},
  year         = {{2024}},
}

@article{62025,
  abstract     = {{<jats:title>ABSTRACT</jats:title><jats:p>This paper deals with micromagnetic measurements for online detection of strain‐induced α′‐martensite during plastic deformation of metastable austenitic steel AISI 304L. The operating principles of the sensors are magnetic Barkhausen noise (MBN) and eddy currents (EC), which are suitable for detection of microstructure evolution due to formation of ferromagnetic phases. The focus of this study was put on the qualification of different micromagnetic techniques and different measurement systems under conditions similar to the real ones during production, which is crucial for implementation of a property‐controlled flow forming process. The investigation was carried out on tubular specimens produced by flow forming, which have different content of α′‐martensite. To characterize the sensitivity of the sensors, different contact conditions between sensors and workpieces were reproduced. MBN sensors are suitable for detecting amount of α′‐martensite, but the measurements are affected by the surface roughness. This entails that the calibration models for MBN sensors must take account of these effects. EC sensors show a closer match with the amount of α′‐martensite without having major affectation by other effects.</jats:p>}},
  author       = {{Rozo Vasquez, Julian and Kanagarajah, Hanigah and Arian, Bahman and Kersting, Lukas and Homberg, Werner and Trächtler, Ansgar and Walther, Frank}},
  issn         = {{2577-8196}},
  journal      = {{Engineering Reports}},
  number       = {{1}},
  publisher    = {{Wiley}},
  title        = {{{Barkhausen Noise‐ and Eddy Current‐Based Measurements for Online Detection of Deformation‐Induced Martensite During Flow Forming of Metastable Austenitic Steel <scp>AISI 304L</scp>}}},
  doi          = {{10.1002/eng2.13070}},
  volume       = {{7}},
  year         = {{2024}},
}

@article{62053,
  abstract     = {{<jats:title>ABSTRACT</jats:title><jats:p>This paper deals with micromagnetic measurements for online detection of strain‐induced α′‐martensite during plastic deformation of metastable austenitic steel AISI 304L. The operating principles of the sensors are magnetic Barkhausen noise (MBN) and eddy currents (EC), which are suitable for detection of microstructure evolution due to formation of ferromagnetic phases. The focus of this study was put on the qualification of different micromagnetic techniques and different measurement systems under conditions similar to the real ones during production, which is crucial for implementation of a property‐controlled flow forming process. The investigation was carried out on tubular specimens produced by flow forming, which have different content of α′‐martensite. To characterize the sensitivity of the sensors, different contact conditions between sensors and workpieces were reproduced. MBN sensors are suitable for detecting amount of α′‐martensite, but the measurements are affected by the surface roughness. This entails that the calibration models for MBN sensors must take account of these effects. EC sensors show a closer match with the amount of α′‐martensite without having major affectation by other effects.</jats:p>}},
  author       = {{Rozo Vasquez, Julian and Kanagarajah, Hanigah and Arian, Bahman and Kersting, Lukas and Homberg, Werner and Trächtler, Ansgar and Walther, Frank}},
  issn         = {{2577-8196}},
  journal      = {{Engineering Reports}},
  number       = {{1}},
  publisher    = {{Wiley}},
  title        = {{{Barkhausen Noise‐ and Eddy Current‐Based Measurements for Online Detection of Deformation‐Induced Martensite During Flow Forming of Metastable Austenitic Steel <scp>AISI 304L</scp>}}},
  doi          = {{10.1002/eng2.13070}},
  volume       = {{7}},
  year         = {{2024}},
}

@inproceedings{48577,
  author       = {{Henkenjohann, Mark and Nolte, Udo and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{2023 International Conference on Unmanned Aircraft Systems (ICUAS)}},
  publisher    = {{IEEE}},
  title        = {{{Novel Cascaded Incremental Nonlinear Dynamic Inversion Controller Approach for a Tiltrotor VTOL}}},
  doi          = {{10.1109/icuas57906.2023.10156317}},
  year         = {{2023}},
}

@inproceedings{44316,
  author       = {{Rozo Vasquez, Julian and Arian, Bahman and Kersting, Lukas and Walther, Frank and Homberg, Werner and Trächtler, Ansgar}},
  location     = {{Krakau}},
  title        = {{{Softsensor model of phase transformation during flow forming of metastable austenitic steel AISI 304L}}},
  year         = {{2023}},
}

@article{48781,
  abstract     = {{In a punch-bending machine, wire products are manufactured for a wide range of industrial sectors, such as the electronics industry. The raw material for this process is flat wire made of high-strength steel. During the manufacturing process of the flat wire, residual stresses and plastic deformations are induced into the wire. These residual stresses and deformations fluctuate over the length of the semi-finished product and have a negative effect on the final product quality. Straightening machines are used to reduce this influence to a minimum. So far, the adjustment of a straightening machine has been performed manually, which is a lengthy and complex task even for an experienced worker. This inevitably leads to the use of inefficient straightening strategies and causes high rejection rates in the entire production process. Due to a lack of sensor information from the straightening operation, application of modern feedback control methods has not been practicable. This paper presents a novel design for a straightening machine with an integrated, precise straightening force measurement. By simultaneously monitoring the position of the straightening rollers, state variables of the straightening operation can be derived. Additionally, a tension control for feeding the flat wire is introduced. This is implemented to mitigate the disturbing effects caused by irregularities in the wire-feeding process. In the results of this article, the high precision of the developed force measurement design and its possible applications are shown.}},
  author       = {{Bathelt, Lukas and Scurk, Maximilian and Djakow, Eugen and Henke, Christian and Trächtler, Ansgar}},
  issn         = {{1424-8220}},
  journal      = {{Sensors}},
  number       = {{22}},
  title        = {{{Novel Straightening-Machine Design with Integrated Force Measurement for Straightening of High-Strength Flat Wire}}},
  doi          = {{10.3390/s23229091}},
  volume       = {{23}},
  year         = {{2023}},
}

@inproceedings{48570,
  author       = {{Lenz, Cederic and Henke, Christian and Trächtler, Ansgar}},
  booktitle    = {{2023 IEEE 21st International Conference on Industrial Informatics (INDIN)}},
  publisher    = {{IEEE}},
  title        = {{{A Methodical Approach to Hybrid Modelling for Contextual Anomaly Detection on Time-Series Data}}},
  doi          = {{10.1109/indin51400.2023.10218108}},
  year         = {{2023}},
}