[{"date_created":"2019-05-13T13:51:59Z","publication":"Sensors and Actuators A: Physical","status":"public","language":[{"iso":"eng"}],"year":"2013","type":"journal_article","volume":200,"_id":"9795","page":"138 - 146","date_updated":"2022-01-06T07:04:20Z","author":[{"first_name":"Waleed","full_name":"Al-Ashtari, Waleed","last_name":"Al-Ashtari"},{"first_name":"Matthias","full_name":"Hunstig, Matthias","last_name":"Hunstig"},{"first_name":"Tobias","full_name":"Hemsel, Tobias","id":"210","last_name":"Hemsel"},{"id":"21220","last_name":"Sextro","full_name":"Sextro, Walter","first_name":"Walter"}],"title":"Enhanced energy harvesting using multiple piezoelectric elements: Theory and experiments","intvolume":" 200","abstract":[{"lang":"eng","text":"Power and bandwidth of piezoelectric harvesters can be increased by using multiple piezoelectric elements in one harvester. In this contribution, a novel energy harvesting cantilever array with magnetic tuning including three piezoelectric bimorphs is investigated theoretically and experimentally, with a good agreement between model and experiment. Other than harvester designs proposed before, this array is easy to manufacture and insensitive to manufacturing tolerances because its optimum operation frequency can be re-adjusted after fabrication. Using the superposition principle, the Butterworth-Van Dyke model and a mechanical lumped parameters model, the generated voltage and current are determined analytically. Formulas for calculating the power generated by array harvesters with an arbitrary number of piezoelectric elements connected in series or in parallel are derived. It is shown that optimum harvester design must take both the connected load and the operating frequency into account. Strategies for connecting multiple bimorphs to increase the maximum generated power and/or enhance the bandwidth compared to a single bimorph harvester are investigated. For bandwidth enhancement it is essential that individual rectifiers are used for the bimorphs. An example with three bimorphs shows that, depending on the chosen tuning strategy, the power is increased by about 340\\% or the bandwidth is increased by about 500\\%, compared to one single bimorph."}],"doi":"10.1016/j.sna.2013.01.008","keyword":["Energy harvesting","Cantilever array","Bandwidth","Power increase"],"user_id":"55222","citation":{"chicago":"Al-Ashtari, Waleed, Matthias Hunstig, Tobias Hemsel, and Walter Sextro. “Enhanced Energy Harvesting Using Multiple Piezoelectric Elements: Theory and Experiments.” Sensors and Actuators A: Physical 200 (2013): 138–46. https://doi.org/10.1016/j.sna.2013.01.008.","ieee":"W. Al-Ashtari, M. Hunstig, T. Hemsel, and W. Sextro, “Enhanced energy harvesting using multiple piezoelectric elements: Theory and experiments,” Sensors and Actuators A: Physical, vol. 200, pp. 138–146, 2013.","ama":"Al-Ashtari W, Hunstig M, Hemsel T, Sextro W. Enhanced energy harvesting using multiple piezoelectric elements: Theory and experiments. Sensors and Actuators A: Physical. 2013;200:138-146. doi:10.1016/j.sna.2013.01.008","apa":"Al-Ashtari, W., Hunstig, M., Hemsel, T., & Sextro, W. (2013). Enhanced energy harvesting using multiple piezoelectric elements: Theory and experiments. Sensors and Actuators A: Physical, 200, 138–146. https://doi.org/10.1016/j.sna.2013.01.008","short":"W. Al-Ashtari, M. Hunstig, T. Hemsel, W. Sextro, Sensors and Actuators A: Physical 200 (2013) 138–146.","mla":"Al-Ashtari, Waleed, et al. “Enhanced Energy Harvesting Using Multiple Piezoelectric Elements: Theory and Experiments.” Sensors and Actuators A: Physical, vol. 200, 2013, pp. 138–46, doi:10.1016/j.sna.2013.01.008.","bibtex":"@article{Al-Ashtari_Hunstig_Hemsel_Sextro_2013, title={Enhanced energy harvesting using multiple piezoelectric elements: Theory and experiments}, volume={200}, DOI={10.1016/j.sna.2013.01.008}, journal={Sensors and Actuators A: Physical}, author={Al-Ashtari, Waleed and Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}, year={2013}, pages={138–146} }"},"department":[{"_id":"151"}]},{"series_title":"Berichte aus dem IDS","citation":{"ieee":"W. Al-Ashtari, M. Hunstig, T. Hemsel, and W. Sextro, “Characteristics of Piezoelectric Energy Harvesters in Autonomous Systems,” in Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 14.-17.7.2013, 2013, no. 05/2013, pp. 159–161.","chicago":"Al-Ashtari, Waleed, Matthias Hunstig, Tobias Hemsel, and Walter Sextro. “Characteristics of Piezoelectric Energy Harvesters in Autonomous Systems.” In Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 14.-17.7.2013, 159–61. Berichte Aus Dem IDS. Hannover, Germany, 2013.","apa":"Al-Ashtari, W., Hunstig, M., Hemsel, T., & Sextro, W. (2013). Characteristics of Piezoelectric Energy Harvesters in Autonomous Systems. In Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 14.-17.7.2013 (pp. 159–161). Hannover, Germany.","ama":"Al-Ashtari W, Hunstig M, Hemsel T, Sextro W. Characteristics of Piezoelectric Energy Harvesters in Autonomous Systems. In: Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 14.-17.7.2013. Berichte aus dem IDS. Hannover, Germany; 2013:159-161.","short":"W. Al-Ashtari, M. Hunstig, T. Hemsel, W. Sextro, in: Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 14.-17.7.2013, Hannover, Germany, 2013, pp. 159–161.","bibtex":"@inproceedings{Al-Ashtari_Hunstig_Hemsel_Sextro_2013, place={Hannover, Germany}, series={Berichte aus dem IDS}, title={Characteristics of Piezoelectric Energy Harvesters in Autonomous Systems}, number={05/2013}, booktitle={Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 14.-17.7.2013}, author={Al-Ashtari, Waleed and Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}, year={2013}, pages={159–161}, collection={Berichte aus dem IDS} }","mla":"Al-Ashtari, Waleed, et al. “Characteristics of Piezoelectric Energy Harvesters in Autonomous Systems.” Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 14.-17.7.2013, no. 05/2013, 2013, pp. 159–61."},"user_id":"55222","keyword":["Energy harvesting","harvester modeling","load dependence","generated voltage"],"department":[{"_id":"151"}],"title":"Characteristics of Piezoelectric Energy Harvesters in Autonomous Systems","author":[{"first_name":"Waleed","full_name":"Al-Ashtari, Waleed","last_name":"Al-Ashtari"},{"first_name":"Matthias","full_name":"Hunstig, Matthias","last_name":"Hunstig"},{"last_name":"Hemsel","id":"210","first_name":"Tobias","full_name":"Hemsel, Tobias"},{"full_name":"Sextro, Walter","first_name":"Walter","id":"21220","last_name":"Sextro"}],"place":"Hannover, Germany","abstract":[{"text":"A basic autonomous system powered by a piezoelectric harvester contains three components apart from the harvester: a fullwave rectifier, a reservoir capacitor and an electronic device performing the primary task of the system. In this contribution, a model describing the operation of such a system is derived. It is found that in steady-state operation, the piezoelectric harvester experiences two alternating load conditions due to the rectification process. These alternating load conditions can have a significant effect on the operation of the harvester and must be considered in the design of autonomous systems. The results also show that such an autonomous system works efficiently if it is connected to a high impedance load and excited by a frequency matching the anti-resonance frequency of the piezoelectric harvester.","lang":"eng"}],"page":"159-161","_id":"9796","date_updated":"2022-01-06T07:04:20Z","issue":"05/2013","publication":"Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 14.-17.7.2013","quality_controlled":"1","date_created":"2019-05-13T13:53:25Z","year":"2013","type":"conference","language":[{"iso":"eng"}],"status":"public"},{"department":[{"_id":"151"}],"citation":{"bibtex":"@inproceedings{Althoff_Neuhaus_Hemsel_Sextro_2013, place={Orlando (Florida), USA}, title={A friction based approach for modeling wire bonding}, DOI={10.4071/isom-2013-TA67}, booktitle={IMAPS 2013, 46th International Symposium on Microelectronics}, author={Althoff, Simon and Neuhaus, Jan and Hemsel, Tobias and Sextro, Walter}, year={2013} }","mla":"Althoff, Simon, et al. “A Friction Based Approach for Modeling Wire Bonding.” IMAPS 2013, 46th International Symposium on Microelectronics, 2013, doi:10.4071/isom-2013-TA67.","short":"S. Althoff, J. Neuhaus, T. Hemsel, W. Sextro, in: IMAPS 2013, 46th International Symposium on Microelectronics, Orlando (Florida), USA, 2013.","ama":"Althoff S, Neuhaus J, Hemsel T, Sextro W. A friction based approach for modeling wire bonding. In: IMAPS 2013, 46th International Symposium on Microelectronics. Orlando (Florida), USA; 2013. doi:10.4071/isom-2013-TA67","apa":"Althoff, S., Neuhaus, J., Hemsel, T., & Sextro, W. (2013). A friction based approach for modeling wire bonding. In IMAPS 2013, 46th International Symposium on Microelectronics. Orlando (Florida), USA. https://doi.org/10.4071/isom-2013-TA67","ieee":"S. Althoff, J. Neuhaus, T. Hemsel, and W. Sextro, “A friction based approach for modeling wire bonding,” in IMAPS 2013, 46th International Symposium on Microelectronics, 2013.","chicago":"Althoff, Simon, Jan Neuhaus, Tobias Hemsel, and Walter Sextro. “A Friction Based Approach for Modeling Wire Bonding.” In IMAPS 2013, 46th International Symposium on Microelectronics. Orlando (Florida), USA, 2013. https://doi.org/10.4071/isom-2013-TA67."},"user_id":"55222","keyword":["Wire bonding","friction modeling","wire bond quality","contact element modeling"],"place":"Orlando (Florida), USA","doi":"10.4071/isom-2013-TA67","abstract":[{"text":"A model approach for wedge/wedge bonding copper wire is presented. The connection between wire and substrate is based on a variety of physical effects, but the dominant one is the friction based welding while applying ultrasound. Consequently, a friction model was used to investigate the welding process. This model is built up universal and can be used to describe the formation of micro welds in the time variant contact area between wire and substrate. Aim of the model is to identify the interactions between touchdown, bond normal force, ultrasonic power and bonding time. To do so, the contact area is discretized into partial areas where a Point Contact Model is applied. Based on this approach it is possible to simulate micro and macro slip inside the contact area between wire and substrate. The work done by friction force is a main criterion to define occurring micro joints which influence the subsequent welding.","lang":"eng"}],"title":"A friction based approach for modeling wire bonding","author":[{"last_name":"Althoff","full_name":"Althoff, Simon","first_name":"Simon"},{"first_name":"Jan","full_name":"Neuhaus, Jan","last_name":"Neuhaus"},{"id":"210","last_name":"Hemsel","full_name":"Hemsel, Tobias","first_name":"Tobias"},{"last_name":"Sextro","id":"21220","full_name":"Sextro, Walter","first_name":"Walter"}],"date_updated":"2022-01-06T07:04:20Z","_id":"9797","type":"conference","year":"2013","language":[{"iso":"eng"}],"status":"public","publication":"IMAPS 2013, 46th International Symposium on Microelectronics","date_created":"2019-05-13T13:55:36Z"},{"title":"Influences of Bonding Parameters on the Tool Wear for Copper Wire Bonding","author":[{"last_name":"Eichwald","first_name":"Paul","full_name":"Eichwald, Paul"},{"id":"21220","last_name":"Sextro","full_name":"Sextro, Walter","first_name":"Walter"},{"last_name":"Althoff","full_name":"Althoff, Simon","first_name":"Simon"},{"last_name":"Eacock","first_name":"Florian","full_name":"Eacock, Florian"},{"last_name":"Schnietz","full_name":"Schnietz, Mark","first_name":"Mark"},{"full_name":"Guth, Karsten","first_name":"Karsten","last_name":"Guth"},{"full_name":"Brökelmann, Michael","first_name":"Michael","last_name":"Brökelmann"}],"project":[{"name":"Intelligente Herstellung zuverlässiger Kupferbondverbindungen","_id":"92","grant_number":"02 PQ2210"}],"doi":"10.1109/EPTC.2013.6745803","abstract":[{"text":"Ultrasonic wire bonding is a common technology for manufacturing electrical interconnects. In the field of power electronics, new thermal and electrical obligations arose due to increasing power density requirements. One approach to achieve these aims is replacing the wire material for heavy wire bonds from aluminum to copper. This material change leads to challenging tasks and problems, for instance the occurring wear of the bond tool. The wear is significantly higher using copper wire instead of aluminum and results in a dramatic loss in the amount of interconnects which can be produced reliable by a single tool. To reduce setting-up time in the production and minimizing costs, an enlarged bonding tool lifetime is desirable. Therefore, the paper discusses the influences of bonding parameters on the wear. The key question is which of the tasks cannot be fulfilled with increased wear of the tool, e.g. loss of process capability. The main functions are fixing the wire in the tool groove, predeformation, applying normal force and transmission of ultrasonic oscillation to the wire. To identify the most affecting factors, four bonding parameters are varied and their influences are investigated. These parameters are: (I) ultrasonic power, (II) tool geometry, (III) the way of tangential force transmission and (IV) loop trajectory.","lang":"eng"}],"citation":{"apa":"Eichwald, P., Sextro, W., Althoff, S., Eacock, F., Schnietz, M., Guth, K., & Brökelmann, M. (2013). Influences of Bonding Parameters on the Tool Wear for Copper Wire Bonding. In 15th Electronics Packaging Technology Conference. https://doi.org/10.1109/EPTC.2013.6745803","ama":"Eichwald P, Sextro W, Althoff S, et al. Influences of Bonding Parameters on the Tool Wear for Copper Wire Bonding. In: 15th Electronics Packaging Technology Conference. ; 2013. doi:10.1109/EPTC.2013.6745803","ieee":"P. Eichwald et al., “Influences of Bonding Parameters on the Tool Wear for Copper Wire Bonding,” in 15th Electronics Packaging Technology Conference, 2013.","chicago":"Eichwald, Paul, Walter Sextro, Simon Althoff, Florian Eacock, Mark Schnietz, Karsten Guth, and Michael Brökelmann. “Influences of Bonding Parameters on the Tool Wear for Copper Wire Bonding.” In 15th Electronics Packaging Technology Conference, 2013. https://doi.org/10.1109/EPTC.2013.6745803.","bibtex":"@inproceedings{Eichwald_Sextro_Althoff_Eacock_Schnietz_Guth_Brökelmann_2013, title={Influences of Bonding Parameters on the Tool Wear for Copper Wire Bonding}, DOI={10.1109/EPTC.2013.6745803}, booktitle={15th Electronics Packaging Technology Conference}, author={Eichwald, Paul and Sextro, Walter and Althoff, Simon and Eacock, Florian and Schnietz, Mark and Guth, Karsten and Brökelmann, Michael}, year={2013} }","mla":"Eichwald, Paul, et al. “Influences of Bonding Parameters on the Tool Wear for Copper Wire Bonding.” 15th Electronics Packaging Technology Conference, 2013, doi:10.1109/EPTC.2013.6745803.","short":"P. Eichwald, W. Sextro, S. Althoff, F. Eacock, M. Schnietz, K. Guth, M. Brökelmann, in: 15th Electronics Packaging Technology Conference, 2013."},"user_id":"210","department":[{"_id":"151"}],"publication":"15th Electronics Packaging Technology Conference","date_created":"2019-05-13T13:57:49Z","year":"2013","type":"conference","language":[{"iso":"eng"}],"status":"public","_id":"9799","date_updated":"2022-01-06T07:04:20Z"},{"page":"359-372","_id":"9801","date_updated":"2022-01-06T07:04:21Z","date_created":"2019-05-13T14:02:10Z","publication":"9. Paderborner Workshop Entwurf mechatronischer Systeme","publisher":"Heinz Nixdorf Institut, Universität Paderborn","language":[{"iso":"eng"}],"year":"2013","type":"conference","status":"public","citation":{"short":"M. Hunstig, W. Al-Ashtari, T. Hemsel, W. Sextro, in: J. Gausemeier, R. Dumitrescu, F. Rammig, W. Schäfer, A. Trächtler (Eds.), 9. Paderborner Workshop Entwurf Mechatronischer Systeme, Heinz Nixdorf Institut, Universität Paderborn, Paderborn, 2013, pp. 359–372.","mla":"Hunstig, Matthias, et al. “Leistungs- Und Bandbreitensteigerung von Energy-Harvesting-Generatoren Für Energieautarke Systeme.” 9. Paderborner Workshop Entwurf Mechatronischer Systeme, edited by Jürgen Gausemeier et al., Heinz Nixdorf Institut, Universität Paderborn, 2013, pp. 359–72.","bibtex":"@inproceedings{Hunstig_Al-Ashtari_Hemsel_Sextro_2013, place={Paderborn}, series={HNI-Verlagsschriftenreihe}, title={Leistungs- und Bandbreitensteigerung von Energy-Harvesting-Generatoren für Energieautarke Systeme}, booktitle={9. Paderborner Workshop Entwurf mechatronischer Systeme}, publisher={Heinz Nixdorf Institut, Universität Paderborn}, author={Hunstig, Matthias and Al-Ashtari, Waleed and Hemsel, Tobias and Sextro, Walter}, editor={Gausemeier, Jürgen and Dumitrescu, Roman and Rammig, Franz and Schäfer, Wilhelm and Trächtler, AnsgarEditors}, year={2013}, pages={359–372}, collection={HNI-Verlagsschriftenreihe} }","chicago":"Hunstig, Matthias, Waleed Al-Ashtari, Tobias Hemsel, and Walter Sextro. “Leistungs- Und Bandbreitensteigerung von Energy-Harvesting-Generatoren Für Energieautarke Systeme.” In 9. Paderborner Workshop Entwurf Mechatronischer Systeme, edited by Jürgen Gausemeier, Roman Dumitrescu, Franz Rammig, Wilhelm Schäfer, and Ansgar Trächtler, 359–72. HNI-Verlagsschriftenreihe. Paderborn: Heinz Nixdorf Institut, Universität Paderborn, 2013.","ieee":"M. Hunstig, W. Al-Ashtari, T. Hemsel, and W. Sextro, “Leistungs- und Bandbreitensteigerung von Energy-Harvesting-Generatoren für Energieautarke Systeme,” in 9. Paderborner Workshop Entwurf mechatronischer Systeme, 2013, pp. 359–372.","ama":"Hunstig M, Al-Ashtari W, Hemsel T, Sextro W. Leistungs- und Bandbreitensteigerung von Energy-Harvesting-Generatoren für Energieautarke Systeme. In: Gausemeier J, Dumitrescu R, Rammig F, Schäfer W, Trächtler A, eds. 9. Paderborner Workshop Entwurf Mechatronischer Systeme. HNI-Verlagsschriftenreihe. Paderborn: Heinz Nixdorf Institut, Universität Paderborn; 2013:359-372.","apa":"Hunstig, M., Al-Ashtari, W., Hemsel, T., & Sextro, W. (2013). Leistungs- und Bandbreitensteigerung von Energy-Harvesting-Generatoren für Energieautarke Systeme. In J. Gausemeier, R. Dumitrescu, F. Rammig, W. Schäfer, & A. Trächtler (Eds.), 9. Paderborner Workshop Entwurf mechatronischer Systeme (pp. 359–372). Paderborn: Heinz Nixdorf Institut, Universität Paderborn."},"series_title":"HNI-Verlagsschriftenreihe","user_id":"55222","department":[{"_id":"151"}],"title":"Leistungs- und Bandbreitensteigerung von Energy-Harvesting-Generatoren für Energieautarke Systeme","author":[{"last_name":"Hunstig","full_name":"Hunstig, Matthias","first_name":"Matthias"},{"full_name":"Al-Ashtari, Waleed","first_name":"Waleed","last_name":"Al-Ashtari"},{"first_name":"Tobias","full_name":"Hemsel, Tobias","id":"210","last_name":"Hemsel"},{"id":"21220","last_name":"Sextro","first_name":"Walter","full_name":"Sextro, Walter"}],"editor":[{"last_name":"Gausemeier","first_name":"Jürgen","full_name":"Gausemeier, Jürgen"},{"full_name":"Dumitrescu, Roman","first_name":"Roman","last_name":"Dumitrescu"},{"full_name":" Rammig, Franz","first_name":"Franz","last_name":" Rammig"},{"last_name":"Schäfer","first_name":"Wilhelm","full_name":"Schäfer, Wilhelm"},{"last_name":"Trächtler","first_name":"Ansgar","full_name":"Trächtler, Ansgar"}],"place":"Paderborn"},{"date_updated":"2022-01-06T07:04:21Z","_id":"9802","page":"16-18","type":"conference","year":"2013","language":[{"iso":"eng"}],"status":"public","publication":"Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop","date_created":"2019-05-13T14:06:14Z","department":[{"_id":"151"}],"citation":{"apa":"Hunstig, M., Hemsel, T., & Sextro, W. (2013). High-Velocity Slip-Slip Operation of Piezoelectric Inertia Motors - Experimental Validation. In Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop (pp. 16–18). Hannover, Germany.","ama":"Hunstig M, Hemsel T, Sextro W. High-Velocity Slip-Slip Operation of Piezoelectric Inertia Motors - Experimental Validation. In: Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop. Hannover, Germany; 2013:16-18.","chicago":"Hunstig, Matthias, Tobias Hemsel, and Walter Sextro. “High-Velocity Slip-Slip Operation of Piezoelectric Inertia Motors - Experimental Validation.” In Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, 16–18. Hannover, Germany, 2013.","ieee":"M. Hunstig, T. Hemsel, and W. Sextro, “High-Velocity Slip-Slip Operation of Piezoelectric Inertia Motors - Experimental Validation,” in Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, 2013, pp. 16–18.","mla":"Hunstig, Matthias, et al. “High-Velocity Slip-Slip Operation of Piezoelectric Inertia Motors - Experimental Validation.” Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, 2013, pp. 16–18.","bibtex":"@inproceedings{Hunstig_Hemsel_Sextro_2013, place={Hannover, Germany}, title={High-Velocity Slip-Slip Operation of Piezoelectric Inertia Motors - Experimental Validation}, booktitle={Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop}, author={Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}, year={2013}, pages={16–18} }","short":"M. Hunstig, T. Hemsel, W. Sextro, in: Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany, 2013, pp. 16–18."},"user_id":"55222","keyword":["Piezoelectric inertia motor","stick-slip motor","driving signal","velocity","smoothness"],"place":"Hannover, Germany","abstract":[{"lang":"eng","text":"It has been shown previously that ``slip-slip'' operation of piezoelectric inertia motors allows higher velocities and smoother movements than classic ``stick-slip'' operation. One very promising driving option is to use a superposition of multiple sinusoidal signals. In this contribution, previous theoretical results are validated experimentally. The results confirm the theoretical result that for a given maximum frequency, usually defined by the actuator characteristics, a signal with high fundamental frequency and consisting of two superposed sine waves leads to the highest velocity and the smoothest motion. This result is of fundamental importance for the further development of high-velocity piezoelectric inertia motors."}],"title":"High-Velocity Slip-Slip Operation of Piezoelectric Inertia Motors - Experimental Validation","author":[{"first_name":"Matthias","full_name":"Hunstig, Matthias","last_name":"Hunstig"},{"id":"210","last_name":"Hemsel","first_name":"Tobias","full_name":"Hemsel, Tobias"},{"first_name":"Walter","full_name":"Sextro, Walter","id":"21220","last_name":"Sextro"}]},{"date_updated":"2022-01-06T07:04:21Z","issue":"11","page":"1380-1391","_id":"9803","volume":24,"type":"journal_article","year":"2013","language":[{"iso":"eng"}],"status":"public","publication":"Journal of Intelligent Material Systems and Structures","date_created":"2019-05-13T14:08:01Z","department":[{"_id":"151"}],"citation":{"ama":"Hunstig M, Hemsel T, Sextro W. Modelling the friction contact in an inertia motor. Journal of Intelligent Material Systems and Structures. 2013;24(11):1380-1391. doi:10.1177/1045389X12474354","apa":"Hunstig, M., Hemsel, T., & Sextro, W. (2013). Modelling the friction contact in an inertia motor. Journal of Intelligent Material Systems and Structures, 24(11), 1380–1391. https://doi.org/10.1177/1045389X12474354","ieee":"M. Hunstig, T. Hemsel, and W. Sextro, “Modelling the friction contact in an inertia motor,” Journal of Intelligent Material Systems and Structures, vol. 24, no. 11, pp. 1380–1391, 2013.","chicago":"Hunstig, Matthias, Tobias Hemsel, and Walter Sextro. “Modelling the Friction Contact in an Inertia Motor.” Journal of Intelligent Material Systems and Structures 24, no. 11 (2013): 1380–91. https://doi.org/10.1177/1045389X12474354.","bibtex":"@article{Hunstig_Hemsel_Sextro_2013, title={Modelling the friction contact in an inertia motor}, volume={24}, DOI={10.1177/1045389X12474354}, number={11}, journal={Journal of Intelligent Material Systems and Structures}, author={Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}, year={2013}, pages={1380–1391} }","mla":"Hunstig, Matthias, et al. “Modelling the Friction Contact in an Inertia Motor.” Journal of Intelligent Material Systems and Structures, vol. 24, no. 11, 2013, pp. 1380–91, doi:10.1177/1045389X12474354.","short":"M. Hunstig, T. Hemsel, W. Sextro, Journal of Intelligent Material Systems and Structures 24 (2013) 1380–1391."},"user_id":"55222","keyword":["Actuator","friction","motor","piezoelectric"],"abstract":[{"text":"Piezoelectric inertia motors, also known as stickslip drives or (smooth) impact drives, use the inertia of a body to drive it by a friction contact in small steps, in the majority of motors composed of a stick phase and a slip phase between the friction partners. For optimizing inertia motors, it is important to understand the friction contact correctly and to measure its properties appropriately. This contribution presents experimental set-ups for measuring the contact force, friction force and relative displacement in an actual inertia motor with a dry friction contact and numerical simulations of the motor operation. The motor uses a pre-stressed multilayer actuator with a displacement in the range of 20 $\\mu$ m. It is shown that a previously postulated condition for the applicability of simple kinetic friction models is well fulfilled for the investigated motor. The friction contact in the motor is simulated using different kinetic friction models. The input for the friction models is the measured motion of the rod. The models qualitatively reproduce the measured motion but show quantitative deviations varying with frequency. These can be explained by vibrations of the driving rod that are experimentally investigated.","lang":"eng"}],"intvolume":" 24","doi":"10.1177/1045389X12474354","title":"Modelling the friction contact in an inertia motor","author":[{"full_name":"Hunstig, Matthias","first_name":"Matthias","last_name":"Hunstig"},{"first_name":"Tobias","full_name":"Hemsel, Tobias","last_name":"Hemsel","id":"210"},{"first_name":"Walter","full_name":"Sextro, Walter","id":"21220","last_name":"Sextro"}]},{"citation":{"mla":"Hunstig, Matthias, et al. “Stick-Slip and Slip-Slip Operation of Piezoelectric Inertia Drives - Part II: Frequency-Limited Excitation.” Sensors and Actuators A: Physical, vol. 200, 2013, pp. 79–89, doi:10.1016/j.sna.2012.11.043.","bibtex":"@article{Hunstig_Hemsel_Sextro_2013, title={Stick-slip and slip-slip operation of piezoelectric inertia drives - Part II: Frequency-limited excitation}, volume={200}, DOI={10.1016/j.sna.2012.11.043}, journal={Sensors and Actuators A: Physical}, author={Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}, year={2013}, pages={79–89} }","short":"M. Hunstig, T. Hemsel, W. Sextro, Sensors and Actuators A: Physical 200 (2013) 79–89.","ama":"Hunstig M, Hemsel T, Sextro W. Stick-slip and slip-slip operation of piezoelectric inertia drives - Part II: Frequency-limited excitation. Sensors and Actuators A: Physical. 2013;200:79-89. doi:10.1016/j.sna.2012.11.043","apa":"Hunstig, M., Hemsel, T., & Sextro, W. (2013). Stick-slip and slip-slip operation of piezoelectric inertia drives - Part II: Frequency-limited excitation. Sensors and Actuators A: Physical, 200, 79–89. https://doi.org/10.1016/j.sna.2012.11.043","chicago":"Hunstig, Matthias, Tobias Hemsel, and Walter Sextro. “Stick-Slip and Slip-Slip Operation of Piezoelectric Inertia Drives - Part II: Frequency-Limited Excitation.” Sensors and Actuators A: Physical 200 (2013): 79–89. https://doi.org/10.1016/j.sna.2012.11.043.","ieee":"M. Hunstig, T. Hemsel, and W. Sextro, “Stick-slip and slip-slip operation of piezoelectric inertia drives - Part II: Frequency-limited excitation,” Sensors and Actuators A: Physical, vol. 200, pp. 79–89, 2013."},"department":[{"_id":"151"}],"author":[{"first_name":"Matthias","full_name":"Hunstig, Matthias","last_name":"Hunstig"},{"id":"210","last_name":"Hemsel","full_name":"Hemsel, Tobias","first_name":"Tobias"},{"last_name":"Sextro","id":"21220","first_name":"Walter","full_name":"Sextro, Walter"}],"intvolume":" 200","_id":"9804","date_updated":"2022-01-06T07:04:21Z","date_created":"2019-05-13T14:09:31Z","language":[{"iso":"eng"}],"year":"2013","status":"public","keyword":["Inertia motor"],"user_id":"55222","title":"Stick-slip and slip-slip operation of piezoelectric inertia drives - Part II: Frequency-limited excitation","abstract":[{"text":"This contribution provides a systematic investigation and performance comparison of different modes of operation for piezoelectric inertia drives. The movement of these motors is classically assumed to consist of steps involving stiction and sliding, resulting in the term ``stick-slip drives''. In the first part of this contribution it has been found that using ideal driving signals, ``slip-slip'' operation without phases of stiction allows very high velocities, while the maximum velocity is limited principally in stick-slip operation. In this part it is shown that slip-slip operation is also suitable for use with real actuators, driven with frequency-limited versions of the ideal signals presented in part I. The motional performance of the motor as well as its wear and the required electric power are investigated for operation with different signals. It is found that for high velocity inertia motors it is recommendable to use actuators with large stroke and to drive them with a signal consisting of two harmonics at a high fundamental frequency, a result that is supported by similar setups implemented experimentally by other authors. Using Lanczos' \\sigma factors to calculate the frequency-limited excitation signals instead of standard Fourier series additionally increases the motor performance significantly. The results help motor designers to choose the appropriate mode of operation and to optimise the motor parameters for their individual applications.","lang":"eng"}],"doi":"10.1016/j.sna.2012.11.043","page":"79 - 89","volume":200,"quality_controlled":"1","publication":"Sensors and Actuators A: Physical","type":"journal_article"},{"author":[{"last_name":"Hunstig","full_name":"Hunstig, Matthias","first_name":"Matthias"},{"full_name":"Hemsel, Tobias","first_name":"Tobias","last_name":"Hemsel","id":"210"},{"last_name":"Sextro","id":"21220","full_name":"Sextro, Walter","first_name":"Walter"}],"intvolume":" 200","citation":{"short":"M. Hunstig, T. Hemsel, W. Sextro, Sensors and Actuators A: Physical 200 (2013) 90–100.","mla":"Hunstig, Matthias, et al. “Stick-Slip and Slip-Slip Operation of Piezoelectric Inertia Drives - Part I: Ideal Excitation.” Sensors and Actuators A: Physical, vol. 200, 2013, pp. 90–100, doi:10.1016/j.sna.2012.11.012.","bibtex":"@article{Hunstig_Hemsel_Sextro_2013, title={Stick-slip and slip-slip operation of piezoelectric inertia drives - Part I: Ideal Excitation.}, volume={200}, DOI={10.1016/j.sna.2012.11.012}, journal={Sensors and Actuators A: Physical}, author={Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}, year={2013}, pages={90–100} }","chicago":"Hunstig, Matthias, Tobias Hemsel, and Walter Sextro. “Stick-Slip and Slip-Slip Operation of Piezoelectric Inertia Drives - Part I: Ideal Excitation.” Sensors and Actuators A: Physical 200 (2013): 90–100. https://doi.org/10.1016/j.sna.2012.11.012.","ieee":"M. Hunstig, T. Hemsel, and W. Sextro, “Stick-slip and slip-slip operation of piezoelectric inertia drives - Part I: Ideal Excitation.,” Sensors and Actuators A: Physical, vol. 200, pp. 90–100, 2013.","ama":"Hunstig M, Hemsel T, Sextro W. Stick-slip and slip-slip operation of piezoelectric inertia drives - Part I: Ideal Excitation. Sensors and Actuators A: Physical. 2013;200:90-100. doi:10.1016/j.sna.2012.11.012","apa":"Hunstig, M., Hemsel, T., & Sextro, W. (2013). Stick-slip and slip-slip operation of piezoelectric inertia drives - Part I: Ideal Excitation. Sensors and Actuators A: Physical, 200, 90–100. https://doi.org/10.1016/j.sna.2012.11.012"},"department":[{"_id":"151"}],"date_created":"2019-05-13T14:10:34Z","status":"public","year":"2013","language":[{"iso":"eng"}],"_id":"9805","date_updated":"2022-01-06T07:04:21Z","title":"Stick-slip and slip-slip operation of piezoelectric inertia drives - Part I: Ideal Excitation.","doi":"10.1016/j.sna.2012.11.012","abstract":[{"lang":"eng","text":"Piezoelectric inertia motors, also known as ``stick--slip drives'', use the inertia of a body to drive it in small steps by means of a friction contact. While these steps are classically assumed to involve stiction and sliding, the motors can also operate in ``slip--slip'' mode without any phase of static friction. This contribution provides a systematic investigation and performance comparison of different stick--slip and slip--slip modes of operation. Different criteria for comparing the motional performance of inertia motors are defined: Steady state velocity, smoothness of motion, and start-up time. Using the example of a translational inertia motor excited by an ideal displacement signal, it is found that the maximum velocity reachable in stick--slip operation is limited principally, while continuous slip--slip operation allows very high velocities. For the investigated driving signals, the motor velocity is proportional to the square root of the actuator stroke. The motor performance with these ideal signals defines an upper boundary for the performance of real motors."}],"user_id":"55222","keyword":["Inertia motor","Stick--slip drive","Mode of operation","Performance indicator","Velocity maximization","Actuator stroke"],"publication":"Sensors and Actuators A: Physical","quality_controlled":"1","type":"journal_article","volume":200,"page":"90 - 100"},{"_id":"9807","page":"619-624","volume":33,"date_updated":"2022-01-06T07:04:21Z","date_created":"2019-05-13T14:13:26Z","publication":"Chemical Engineering Transactions","language":[{"iso":"eng"}],"year":"2013","type":"journal_article","status":"public","citation":{"ama":"Kimotho JK, Sondermann-Wölke C, Meyer T, Sextro W. Machinery Prognostic Method Based on Multi-Class Support Vector Machines and Hybrid Differential Evolution -- Particle Swarm Optimization. Chemical Engineering Transactions. 2013;33:619-624. doi:10.3303/CET1333104","apa":"Kimotho, J. K., Sondermann-Wölke, C., Meyer, T., & Sextro, W. (2013). Machinery Prognostic Method Based on Multi-Class Support Vector Machines and Hybrid Differential Evolution -- Particle Swarm Optimization. Chemical Engineering Transactions, 33, 619–624. https://doi.org/10.3303/CET1333104","ieee":"J. K. Kimotho, C. Sondermann-Wölke, T. Meyer, and W. Sextro, “Machinery Prognostic Method Based on Multi-Class Support Vector Machines and Hybrid Differential Evolution -- Particle Swarm Optimization,” Chemical Engineering Transactions, vol. 33, pp. 619–624, 2013.","chicago":"Kimotho, James Kuria, Christopher Sondermann-Wölke, Tobias Meyer, and Walter Sextro. “Machinery Prognostic Method Based on Multi-Class Support Vector Machines and Hybrid Differential Evolution -- Particle Swarm Optimization.” Chemical Engineering Transactions 33 (2013): 619–24. https://doi.org/10.3303/CET1333104.","bibtex":"@article{Kimotho_Sondermann-Wölke_Meyer_Sextro_2013, title={Machinery Prognostic Method Based on Multi-Class Support Vector Machines and Hybrid Differential Evolution -- Particle Swarm Optimization}, volume={33}, DOI={10.3303/CET1333104}, journal={Chemical Engineering Transactions}, author={Kimotho, James Kuria and Sondermann-Wölke, Christopher and Meyer, Tobias and Sextro, Walter}, year={2013}, pages={619–624} }","mla":"Kimotho, James Kuria, et al. “Machinery Prognostic Method Based on Multi-Class Support Vector Machines and Hybrid Differential Evolution -- Particle Swarm Optimization.” Chemical Engineering Transactions, vol. 33, 2013, pp. 619–24, doi:10.3303/CET1333104.","short":"J.K. Kimotho, C. Sondermann-Wölke, T. Meyer, W. Sextro, Chemical Engineering Transactions 33 (2013) 619–624."},"user_id":"55222","department":[{"_id":"151"}],"title":"Machinery Prognostic Method Based on Multi-Class Support Vector Machines and Hybrid Differential Evolution -- Particle Swarm Optimization","author":[{"last_name":"Kimotho","first_name":"James Kuria","full_name":"Kimotho, James Kuria"},{"last_name":"Sondermann-Wölke","full_name":"Sondermann-Wölke, Christopher","first_name":"Christopher"},{"full_name":"Meyer, Tobias","first_name":"Tobias","last_name":"Meyer"},{"last_name":"Sextro","id":"21220","first_name":"Walter","full_name":"Sextro, Walter"}],"abstract":[{"text":"Recently, focus on maintenance strategies has been shifted towards prognostic health management (PHM) and a number of state of the art algorithms based on data-driven prognostics have been developed to predict the health states of degrading components based on sensory data. Amongst these algorithms, Multiclass Support Vector Machines (MC-SVM) has gained popularity due to its relatively high classification accuracy, ability to classify multiple patterns and capability to handle noisy /incomplete data. However, its application is limited by the difficulty in determining the required kernel function and penalty parameters. To address this problem, this paper proposes a hybrid differential evolution -- particle swarm optimization (DE-PSO) algorithm to optimize the MC-SVM kernel function and penalty parameters. The differential algorithm (DE) obtains the search limit for the SVM parameters, while the particle swarm optimization algorithm (PSO) determines the global optimum parameters for a given training data set. Since degrading machinery components display several degradation stages in their lifetime, the MC-SVM trained with optimum parameters are used to estimate the health states of a degrading machinery component, from which the remaining useful life (RUL) is predicted. This method improves the classification accuracy of MC-SVM in predicting the health states of a machinery component and consequently increases the accuracy of RUL predictions. The feasibility of the method is validated using bearing prognostic run-to-failure data obtained from NASA public data repository. A comparative study between MC-SVM with parameters obtained using simple grid search with n-fold cross validation and MCSVM with DE-PSO based on prognostic performance metrics reveals that the proposed method has better performance, with all the cases considered falling within a 10 \\% error margin. The method also outperforms other soft computing methods proposed in literature.","lang":"eng"}],"doi":"10.3303/CET1333104","intvolume":" 33"},{"status":"public","language":[{"iso":"eng"}],"type":"journal_article","year":"2013","date_created":"2019-05-13T14:15:36Z","publication":"International Journal of Prognostics and Health Management","quality_controlled":"1","issue":"2","date_updated":"2022-01-06T07:04:21Z","volume":4,"_id":"9808","intvolume":" 4","abstract":[{"text":"This study presents the methods employed by a team from the department of Mechatronics and Dynamics at the University of Paderborn, Germany for the 2013 PHM data challenge. The focus of the challenge was on maintenance action recommendation for an industrial machinery based on remote monitoring and diagnosis. Since an ensemble of data driven methods has been considered as the state of the art approach in diagnosis and prognosis, the first approach was to evaluate the performance of an ensemble of data driven methods using the parametric data as input and problems (recommended maintenance action) as the output. Due to close correlation of parametric data of different problems, this approach produced high misclassification rate. Event-based decision trees were then constructed to identify problems associated with particular events. To distinguish between problems associated with events that appeared in multiple problems, support vector machine (SVM) with parameters optimally tuned using particle swarm optimization (PSO) was employed. Parametric data was used as the input to the SVM algorithm and majority voting was employed to determine the final decision for cases with multiple events. A total of 165 SVM models were constructed. This approach improved the overall score from 21 to 48. The method was further enhanced by employing an ensemble of three data driven methods, that is, SVM, random forests (RF) and bagged trees (BT), to build the event based models. With this approach, a score of 51 was obtained . The results demonstrate that the proposed event based method can be effective in maintenance action recommendation based on events codes and parametric data acquired remotely from an industrial equipment.","lang":"eng"}],"author":[{"first_name":"James Kuria","full_name":"Kimotho, James Kuria","last_name":"Kimotho"},{"full_name":"Sondermann-Wölke, Chritoph","first_name":"Chritoph","last_name":"Sondermann-Wölke"},{"last_name":"Meyer","first_name":"Tobias","full_name":"Meyer, Tobias"},{"first_name":"Walter","full_name":"Sextro, Walter","last_name":"Sextro","id":"21220"}],"title":"Application of Event Based Decision Tree and Ensemble of Data Driven Methods for Maintenance Action Recommendation","department":[{"_id":"151"}],"keyword":["maintenance decision","Bagged trees","Decision trees","PSO-SVM","Random forests"],"user_id":"55222","citation":{"apa":"Kimotho, J. K., Sondermann-Wölke, C., Meyer, T., & Sextro, W. (2013). Application of Event Based Decision Tree and Ensemble of Data Driven Methods for Maintenance Action Recommendation. International Journal of Prognostics and Health Management, 4(2).","ama":"Kimotho JK, Sondermann-Wölke C, Meyer T, Sextro W. Application of Event Based Decision Tree and Ensemble of Data Driven Methods for Maintenance Action Recommendation. International Journal of Prognostics and Health Management. 2013;4(2).","ieee":"J. K. Kimotho, C. Sondermann-Wölke, T. Meyer, and W. Sextro, “Application of Event Based Decision Tree and Ensemble of Data Driven Methods for Maintenance Action Recommendation,” International Journal of Prognostics and Health Management, vol. 4, no. 2, 2013.","chicago":"Kimotho, James Kuria, Chritoph Sondermann-Wölke, Tobias Meyer, and Walter Sextro. “Application of Event Based Decision Tree and Ensemble of Data Driven Methods for Maintenance Action Recommendation.” International Journal of Prognostics and Health Management 4, no. 2 (2013).","bibtex":"@article{Kimotho_Sondermann-Wölke_Meyer_Sextro_2013, title={Application of Event Based Decision Tree and Ensemble of Data Driven Methods for Maintenance Action Recommendation}, volume={4}, number={2}, journal={International Journal of Prognostics and Health Management}, author={Kimotho, James Kuria and Sondermann-Wölke, Chritoph and Meyer, Tobias and Sextro, Walter}, year={2013} }","mla":"Kimotho, James Kuria, et al. “Application of Event Based Decision Tree and Ensemble of Data Driven Methods for Maintenance Action Recommendation.” International Journal of Prognostics and Health Management, vol. 4, no. 2, 2013.","short":"J.K. Kimotho, C. Sondermann-Wölke, T. Meyer, W. Sextro, International Journal of Prognostics and Health Management 4 (2013)."}},{"page":"23-24","_id":"9855","volume":13,"date_updated":"2019-05-20T11:03:25Z","date_created":"2019-05-20T11:01:42Z","publication":"Proc. Appl. Math. Mech.","language":[{"iso":"eng"}],"year":"2013","type":"conference","status":"public","citation":{"short":"S. Kohl, A. Zuber, W. Sextro, in: Proc. Appl. Math. Mech., 2013, pp. 23–24.","bibtex":"@inproceedings{Kohl_Zuber_Sextro_2013, title={Modelbased Investigations of Gyroscopic Effect on the (Elasto-)Kinematics of Suspension Systems}, volume={13}, DOI={10.1002/pamm.201310007}, booktitle={Proc. Appl. Math. Mech.}, author={Kohl, Sergej and Zuber, Armin and Sextro, Walter}, year={2013}, pages={23–24} }","mla":"Kohl, Sergej, et al. “Modelbased Investigations of Gyroscopic Effect on the (Elasto-)Kinematics of Suspension Systems.” Proc. Appl. Math. Mech., vol. 13, 2013, pp. 23–24, doi:10.1002/pamm.201310007.","ieee":"S. Kohl, A. Zuber, and W. Sextro, “Modelbased Investigations of Gyroscopic Effect on the (Elasto-)Kinematics of Suspension Systems,” in Proc. Appl. Math. Mech., 2013, vol. 13, pp. 23–24.","chicago":"Kohl, Sergej, Armin Zuber, and Walter Sextro. “Modelbased Investigations of Gyroscopic Effect on the (Elasto-)Kinematics of Suspension Systems.” In Proc. Appl. Math. Mech., 13:23–24, 2013. https://doi.org/10.1002/pamm.201310007.","ama":"Kohl S, Zuber A, Sextro W. Modelbased Investigations of Gyroscopic Effect on the (Elasto-)Kinematics of Suspension Systems. In: Proc. Appl. Math. Mech. Vol 13. ; 2013:23-24. doi:10.1002/pamm.201310007","apa":"Kohl, S., Zuber, A., & Sextro, W. (2013). Modelbased Investigations of Gyroscopic Effect on the (Elasto-)Kinematics of Suspension Systems. In Proc. Appl. Math. Mech. (Vol. 13, pp. 23–24). https://doi.org/10.1002/pamm.201310007"},"user_id":"55222","department":[{"_id":"151"}],"title":"Modelbased Investigations of Gyroscopic Effect on the (Elasto-)Kinematics of Suspension Systems","author":[{"last_name":"Kohl","full_name":"Kohl, Sergej","first_name":"Sergej"},{"full_name":"Zuber, Armin","first_name":"Armin","last_name":"Zuber"},{"id":"21220","last_name":"Sextro","full_name":"Sextro, Walter","first_name":"Walter"}],"doi":"10.1002/pamm.201310007","abstract":[{"lang":"eng","text":"During wheel bumping caused by stochastic road excitation, the wheel performs rotational and translational movements. The bump and rebound wheel velocity leads to significant angular velocities based on the (elasto-)kinematics of the suspension system. Based on the gyroscopic effect, moments arise about the rotating wheel induced by the angular change while bumping. Therefore it leads to undesirable wheel changes and degrades the tire contact and finally decreases the driving stability. A flexible MBS-model of the five-link rear axle system that includes these effects has been built up to allow a detailed investigation of the gyroscopic effect. Using the simulation results, conclusions can be drawn for refining design criteria for the kinematics, elastokinematics and topology of the suspension system to increase the active safety of the vehicle"}],"intvolume":" 13"},{"department":[{"_id":"151"}],"citation":{"short":"T. Meyer, C. Hölscher, M. Menke, W. Sextro, D. Zimmer, in: Proc. Appl. Math. Mech., 2013, pp. 483–484.","mla":"Meyer, Tobias, et al. “Multiobjective Optimization Including Safety of Operation Applied to a Linear Drive System.” Proc. Appl. Math. Mech., vol. 13, 2013, pp. 483–84, doi:10.1002/pamm.201310234.","bibtex":"@inproceedings{Meyer_Hölscher_Menke_Sextro_Zimmer_2013, title={Multiobjective Optimization including Safety of Operation Applied to a Linear Drive System}, volume={13}, DOI={10.1002/pamm.201310234}, booktitle={Proc. Appl. Math. Mech.}, author={Meyer, Tobias and Hölscher, Christina and Menke, Michael and Sextro, Walter and Zimmer, Detmar}, year={2013}, pages={483–484} }","chicago":"Meyer, Tobias, Christina Hölscher, Michael Menke, Walter Sextro, and Detmar Zimmer. “Multiobjective Optimization Including Safety of Operation Applied to a Linear Drive System.” In Proc. Appl. Math. Mech., 13:483–84, 2013. https://doi.org/10.1002/pamm.201310234.","ieee":"T. Meyer, C. Hölscher, M. Menke, W. Sextro, and D. Zimmer, “Multiobjective Optimization including Safety of Operation Applied to a Linear Drive System,” in Proc. Appl. Math. Mech., 2013, vol. 13, pp. 483–484.","ama":"Meyer T, Hölscher C, Menke M, Sextro W, Zimmer D. Multiobjective Optimization including Safety of Operation Applied to a Linear Drive System. In: Proc. Appl. Math. Mech. Vol 13. ; 2013:483-484. doi:10.1002/pamm.201310234","apa":"Meyer, T., Hölscher, C., Menke, M., Sextro, W., & Zimmer, D. (2013). Multiobjective Optimization including Safety of Operation Applied to a Linear Drive System. In Proc. Appl. Math. Mech. (Vol. 13, pp. 483–484). https://doi.org/10.1002/pamm.201310234"},"user_id":"55222","abstract":[{"lang":"eng","text":"In this contribution, we introduce a multiobjective optimization used to calculate safe optimal working points for a mechatronic system by including stochastic safety-critical signals in an objective function. Our application example consists of a linear drive for a rail-bound vehicle and an actuation unit. The linear drive's secondary part is fixed; the primary part is vehicle-mounted and can be adjusted vertically to account for deviations of the height of the secondary part. A small air gap between both parts improves efficiency, but increases the risk of a collision between the two parts. Using height data of the secondary part, a trajectory for the vertical adjustment of the primary part is calculated. However, unexpected deviations necessitate a readjustment of the air gap. The probability of such unexpected height deviations can be calculated from the readjustment data. The system is equipped with sensors to measure the air gap. Assuming that the sensor noise is normally distributed, noise characteristics are determined. Using this information and the probability distribution of unexpected height deviations, the probability of a collision is determined.T he sensor noise and the probability of a collision between both parts of the linear drive are included in the dynamical model of the system. Using multiobjective optimization, pareto-optimal working points for the controller of the air gap are obtained. By selecting an appropriate working point, safe operation can be ensured."}],"intvolume":" 13","doi":"10.1002/pamm.201310234","title":"Multiobjective Optimization including Safety of Operation Applied to a Linear Drive System","author":[{"full_name":"Meyer, Tobias","first_name":"Tobias","last_name":"Meyer"},{"full_name":"Hölscher, Christina","first_name":"Christina","last_name":"Hölscher"},{"last_name":"Menke","full_name":"Menke, Michael","first_name":"Michael"},{"id":"21220","last_name":"Sextro","full_name":"Sextro, Walter","first_name":"Walter"},{"last_name":"Zimmer","full_name":"Zimmer, Detmar","first_name":"Detmar"}],"date_updated":"2019-05-20T11:12:54Z","page":"483-484","_id":"9858","volume":13,"language":[{"iso":"eng"}],"type":"conference","year":"2013","status":"public","date_created":"2019-05-20T11:10:20Z","publication":"Proc. Appl. Math. Mech."},{"_id":"9859","date_updated":"2019-09-16T11:22:45Z","publication":"Proceedings of the Annual Reliability and Maintainability Symposium (RAMS)","quality_controlled":"1","date_created":"2019-05-20T11:13:14Z","year":"2013","type":"conference","language":[{"iso":"eng"}],"status":"public","citation":{"short":"T. Meyer , J. Henning Keßler, W. Sextro, A. Trächtler, in: Proceedings of the Annual Reliability and Maintainability Symposium (RAMS), Orlando, FL, 2013.","mla":"Meyer , Tobias, et al. “Increasing Intelligent Systems’ Reliability by Using Reconfiguration.” Proceedings of the Annual Reliability and Maintainability Symposium (RAMS), 2013, doi:10.1109/RAMS.2013.6517636.","bibtex":"@inproceedings{Meyer _Henning Keßler_Sextro_Trächtler_2013, place={Orlando, FL}, title={Increasing Intelligent Systems’ Reliability by Using Reconfiguration}, DOI={10.1109/RAMS.2013.6517636}, booktitle={Proceedings of the Annual Reliability and Maintainability Symposium (RAMS)}, author={Meyer , Tobias and Henning Keßler, Jan and Sextro, Walter and Trächtler, Ansgar}, year={2013} }","chicago":"Meyer , Tobias, Jan Henning Keßler, Walter Sextro, and Ansgar Trächtler. “Increasing Intelligent Systems’ Reliability by Using Reconfiguration.” In Proceedings of the Annual Reliability and Maintainability Symposium (RAMS). Orlando, FL, 2013. https://doi.org/10.1109/RAMS.2013.6517636.","ieee":"T. Meyer , J. Henning Keßler, W. Sextro, and A. Trächtler, “Increasing Intelligent Systems’ Reliability by Using Reconfiguration,” in Proceedings of the Annual Reliability and Maintainability Symposium (RAMS), 2013.","ama":"Meyer T, Henning Keßler J, Sextro W, Trächtler A. Increasing Intelligent Systems’ Reliability by Using Reconfiguration. In: Proceedings of the Annual Reliability and Maintainability Symposium (RAMS). Orlando, FL; 2013. doi:10.1109/RAMS.2013.6517636","apa":"Meyer , T., Henning Keßler, J., Sextro, W., & Trächtler, A. (2013). Increasing Intelligent Systems’ Reliability by Using Reconfiguration. In Proceedings of the Annual Reliability and Maintainability Symposium (RAMS). Orlando, FL. https://doi.org/10.1109/RAMS.2013.6517636"},"user_id":"55222","department":[{"_id":"151"}],"title":"Increasing Intelligent Systems' Reliability by Using Reconfiguration","author":[{"first_name":"Tobias","full_name":"Meyer , Tobias","last_name":"Meyer "},{"full_name":"Henning Keßler, Jan","first_name":"Jan","last_name":"Henning Keßler"},{"full_name":"Sextro, Walter","first_name":"Walter","last_name":"Sextro","id":"21220"},{"full_name":"Trächtler, Ansgar","first_name":"Ansgar","last_name":"Trächtler"}],"place":"Orlando, FL","abstract":[{"lang":"eng","text":"Self-optimizing mechatronic systems allow the adaptation of the system's behavior to the current situation. This can be used to actively adapt the behavior to the current degradation state of the system or of some of its components. To this end, the Multi-Level Dependability Concept has been developed. In this contribution, we show how the Multi-Level Dependability Concept has been applied to the active suspension module of an innovative rail-bound vehicle. For this module, the usage of control reconfiguration, which is a novel approach to exploit complex redundancy systems, is required. We show that by combining self-optimization with the possibilities given by control reconfiguration, the dependability of a complex mechatronic system can be greatly improved."}],"doi":"10.1109/RAMS.2013.6517636"},{"date_created":"2019-05-20T11:15:59Z","publication":"Chemical Engineering Transactions","quality_controlled":"1","language":[{"iso":"eng"}],"year":"2013","type":"journal_article","status":"public","page":"625-630","_id":"9860","volume":33,"date_updated":"2019-09-16T11:20:50Z","title":"Controlling the Remaining Useful Lifetime using Self-Optimization","author":[{"full_name":"Meyer, Tobias","first_name":"Tobias","last_name":"Meyer"},{"last_name":"Sondermann-Wölke","full_name":"Sondermann-Wölke, Christoph","first_name":"Christoph"},{"last_name":"Kimotho","full_name":"Kimotho, James Kuria","first_name":"James Kuria"},{"full_name":"Sextro, Walter","first_name":"Walter","id":"21220","last_name":"Sextro"}],"doi":"10.3303/CET1333105","intvolume":" 33","abstract":[{"lang":"eng","text":"Self-optimizing mechatronic systems offer possibilities well beyond those of traditional mechatronic systems. Among these is the adaptation of the system behavior to the current situation. To do so, they are able to choose from different working points, which are pre-calculated using multiobjective optimization and are thus Pareto-optimal with regard to the chosen objective functions. In this contribution, a method is presented that allows to continuously control the system degradation by adapting the behavior of a selfoptimizing system throughout its complete lifetime. The current remaining useful lifetime is estimated and then related to the spent lifetime and the desired useful lifetime. Using this information, a reliability-related objective is prioritized using a closed-loop control, which in turn is used to determine the working point of the self-optimizing system. This way, the desired useful lifetime can be achieved. To exemplify the setup of the controller structure and to demonstrate the adaptation of the system behavior, a dynamic model of a clutch system is used. It can be seen that the closed loop controller is able to correct for external perturbations, such as changed requirements, as well as changed system parameters. This way, the modeled system is able to achieve the desired lifetime reliably."}],"citation":{"short":"T. Meyer, C. Sondermann-Wölke, J.K. Kimotho, W. Sextro, Chemical Engineering Transactions 33 (2013) 625–630.","bibtex":"@article{Meyer_Sondermann-Wölke_Kimotho_Sextro_2013, title={Controlling the Remaining Useful Lifetime using Self-Optimization}, volume={33}, DOI={10.3303/CET1333105}, journal={Chemical Engineering Transactions}, author={Meyer, Tobias and Sondermann-Wölke, Christoph and Kimotho, James Kuria and Sextro, Walter}, year={2013}, pages={625–630} }","mla":"Meyer, Tobias, et al. “Controlling the Remaining Useful Lifetime Using Self-Optimization.” Chemical Engineering Transactions, vol. 33, 2013, pp. 625–30, doi:10.3303/CET1333105.","ieee":"T. Meyer, C. Sondermann-Wölke, J. K. Kimotho, and W. Sextro, “Controlling the Remaining Useful Lifetime using Self-Optimization,” Chemical Engineering Transactions, vol. 33, pp. 625–630, 2013.","chicago":"Meyer, Tobias, Christoph Sondermann-Wölke, James Kuria Kimotho, and Walter Sextro. “Controlling the Remaining Useful Lifetime Using Self-Optimization.” Chemical Engineering Transactions 33 (2013): 625–30. https://doi.org/10.3303/CET1333105.","ama":"Meyer T, Sondermann-Wölke C, Kimotho JK, Sextro W. Controlling the Remaining Useful Lifetime using Self-Optimization. Chemical Engineering Transactions. 2013;33:625-630. doi:10.3303/CET1333105","apa":"Meyer, T., Sondermann-Wölke, C., Kimotho, J. K., & Sextro, W. (2013). Controlling the Remaining Useful Lifetime using Self-Optimization. Chemical Engineering Transactions, 33, 625–630. https://doi.org/10.3303/CET1333105"},"user_id":"55222","department":[{"_id":"151"}]},{"citation":{"short":"T. Meyer, C. Sondermann-Wölke, W. Sextro, M. Riedl, A. Gouberman, M. Siegle, in: J. Gausemeier, R. Dumitrescu, F. Rammig, W. Schäfer, A. Trächtler (Eds.), 9. Paderborner Workshop Entwurf Mechatronischer Systeme, Heinz Nixdorf Institut, Universität Paderborn, Paderborn, 2013, pp. 161–174.","mla":"Meyer, Tobias, et al. “Bewertung Der Zuverlässigkeit Selbstoptimierender Systeme Mit Dem LARES-Framework.” 9. Paderborner Workshop Entwurf Mechatronischer Systeme, edited by Jürgen Gausemeier et al., Heinz Nixdorf Institut, Universität Paderborn, 2013, pp. 161–74.","bibtex":"@inproceedings{Meyer_Sondermann-Wölke_Sextro_Riedl_Gouberman_Siegle_2013, place={Paderborn}, series={HNI-Verlagsschriftenreihe}, title={Bewertung der Zuverlässigkeit selbstoptimierender Systeme mit dem LARES-Framework}, booktitle={9. Paderborner Workshop Entwurf mechatronischer Systeme}, publisher={Heinz Nixdorf Institut, Universität Paderborn}, author={Meyer, Tobias and Sondermann-Wölke, Christoph and Sextro, Walter and Riedl, Martin and Gouberman, Alexander and Siegle, Markus}, editor={Gausemeier, Jürgen and Dumitrescu, Roman and Rammig, Franz and Schäfer, Wilhelm and Trächtler, AnsgarEditors}, year={2013}, pages={161–174}, collection={HNI-Verlagsschriftenreihe} }","chicago":"Meyer, Tobias, Christoph Sondermann-Wölke, Walter Sextro, Martin Riedl, Alexander Gouberman, and Markus Siegle. “Bewertung Der Zuverlässigkeit Selbstoptimierender Systeme Mit Dem LARES-Framework.” In 9. Paderborner Workshop Entwurf Mechatronischer Systeme, edited by Jürgen Gausemeier, Roman Dumitrescu, Franz Rammig, Wilhelm Schäfer, and Ansgar Trächtler, 161–74. HNI-Verlagsschriftenreihe. Paderborn: Heinz Nixdorf Institut, Universität Paderborn, 2013.","ieee":"T. Meyer, C. Sondermann-Wölke, W. Sextro, M. Riedl, A. Gouberman, and M. Siegle, “Bewertung der Zuverlässigkeit selbstoptimierender Systeme mit dem LARES-Framework,” in 9. Paderborner Workshop Entwurf mechatronischer Systeme, 2013, pp. 161–174.","apa":"Meyer, T., Sondermann-Wölke, C., Sextro, W., Riedl, M., Gouberman, A., & Siegle, M. (2013). Bewertung der Zuverlässigkeit selbstoptimierender Systeme mit dem LARES-Framework. In J. Gausemeier, R. Dumitrescu, F. Rammig, W. Schäfer, & A. Trächtler (Eds.), 9. Paderborner Workshop Entwurf mechatronischer Systeme (pp. 161–174). Paderborn: Heinz Nixdorf Institut, Universität Paderborn.","ama":"Meyer T, Sondermann-Wölke C, Sextro W, Riedl M, Gouberman A, Siegle M. Bewertung der Zuverlässigkeit selbstoptimierender Systeme mit dem LARES-Framework. In: Gausemeier J, Dumitrescu R, Rammig F, Schäfer W, Trächtler A, eds. 9. Paderborner Workshop Entwurf Mechatronischer Systeme. HNI-Verlagsschriftenreihe. Paderborn: Heinz Nixdorf Institut, Universität Paderborn; 2013:161-174."},"series_title":"HNI-Verlagsschriftenreihe","user_id":"55222","department":[{"_id":"151"}],"title":"Bewertung der Zuverlässigkeit selbstoptimierender Systeme mit dem LARES-Framework","editor":[{"last_name":"Gausemeier","first_name":"Jürgen","full_name":"Gausemeier, Jürgen"},{"last_name":"Dumitrescu","first_name":"Roman","full_name":"Dumitrescu, Roman"},{"full_name":"Rammig, Franz","first_name":"Franz","last_name":"Rammig"},{"last_name":"Schäfer","first_name":"Wilhelm","full_name":"Schäfer, Wilhelm"},{"last_name":"Trächtler","full_name":"Trächtler, Ansgar","first_name":"Ansgar"}],"author":[{"first_name":"Tobias","full_name":"Meyer, Tobias","last_name":"Meyer"},{"last_name":"Sondermann-Wölke","full_name":"Sondermann-Wölke, Christoph","first_name":"Christoph"},{"last_name":"Sextro","id":"21220","full_name":"Sextro, Walter","first_name":"Walter"},{"full_name":"Riedl, Martin","first_name":"Martin","last_name":"Riedl"},{"last_name":"Gouberman","full_name":"Gouberman, Alexander","first_name":"Alexander"},{"last_name":"Siegle","full_name":"Siegle, Markus","first_name":"Markus"}],"place":"Paderborn","abstract":[{"lang":"eng","text":"Selbstoptimierende mechatronische Systeme bieten die Möglichkeit, ihr Verhalten an geänderte Umgebungsbedingungen anzupassen. Dazu werden beispielsweise redundante Strukturen genutzt, Reglerparameter angepasst oder Regelstrategien umgeschaltet. Dies kann auch genutzt werden, um die Zuverlässigkeit des Systems zu steigern. Zugleich entstehen aber durch die gesteigerte Komplexität dieser Systeme zusätzliche Risiken. Um sicherzustellen, dass das System dennoch die gestellten Anforderungen bezüglich der Zuverlässigkeit erfüllt, ist eine Modellierung des Gesamtsystems und anschließende Zuverlässigkeitsbewertung notwendig. Dies ist aufgrund der situationsabhängigen Verhaltensanpassung und des nicht intuitiv vorhersehbaren Verhaltens jedoch nicht mit klassischen Verfahren möglich. Ein Modellierungsverfahren, das diese Eigenschaften abbilden kann, ist LARES (LAnguage for REconfigurable dependable Systems). Die Anwendung von LARES zur Bewertung der Zuverlässigkeit eines selbstoptimierenden Systems wird anhand des Feder-Neige-Moduls gezeigt. Es ist eine Baugruppe der Fahrzeuge eines innovativen Bahnsystems, der RailCabs. Das Feder-Neige-Modul dient dazu, unerwünschte Schwingungen des Fahrzeugaufbaus zu minimieren. Mit LARES können die Hardware-Komponenten des Systems, ihre in Abhängigkeit von der aktuellen Situation veränderten Belastungen sowie die nicht-deterministische Verhaltensadaption modelliert werden."}],"_id":"9861","page":"161-174","date_updated":"2019-09-30T08:10:44Z","date_created":"2019-05-20T11:18:06Z","publication":"9. Paderborner Workshop Entwurf mechatronischer Systeme","quality_controlled":"1","publisher":"Heinz Nixdorf Institut, Universität Paderborn","language":[{"iso":"eng"}],"year":"2013","type":"conference","status":"public"},{"type":"journal_article","year":"2012","language":[{"iso":"eng"}],"status":"public","publication":"Smart Materials and Structures","quality_controlled":"1","date_created":"2019-05-13T13:16:33Z","date_updated":"2022-01-06T07:04:20Z","issue":"3","page":"035019","_id":"9781","volume":21,"abstract":[{"lang":"eng","text":"A piezoelectric energy harvester is an electromechanical device that converts ambient mechanical vibration into electric power. Most existing vibration energy harvesting devices operate effectively at a single frequency only, dictated by the design of the device. This frequency must match the frequency of the host structure vibration. However, real world structural vibrations rarely have a specific constant frequency. Therefore, piezoelectric harvesters that generate usable power across a range of exciting frequencies are required to make this technology commercially viable. Currently known harvester tuning techniques have many limitations, in particular they miss the ability to work during harvester operation and most often cannot perform a precise tuning. This paper describes the design and testing of a vibration energy harvester with tunable resonance frequency, wherein the tuning is accomplished by changing the attraction force between two permanent magnets by adjusting the distance between the magnets. This tuning technique allows the natural frequency to be manipulated before and during operation of the harvester. Furthermore the paper presents a physical description of the frequency tuning effect. The experimental results achieved with a piezoelectric bimorph fit the calculated results very well. The calculation and experimental results show that using this tuning technique the natural frequency of the harvester can be varied efficiently within a wide range: in the test setup, the natural frequency of the piezoelectric bimorph could be increased by more than 70\\%."}],"intvolume":" 21","title":"Frequency tuning of piezoelectric energy harvesters by magnetic force","author":[{"last_name":"Al-Ashtari","full_name":"Al-Ashtari, Waleed","first_name":"Waleed"},{"first_name":"Matthias","full_name":"Hunstig, Matthias","last_name":"Hunstig"},{"last_name":"Hemsel","id":"210","full_name":"Hemsel, Tobias","first_name":"Tobias"},{"full_name":"Sextro, Walter","first_name":"Walter","id":"21220","last_name":"Sextro"}],"department":[{"_id":"151"}],"citation":{"mla":"Al-Ashtari, Waleed, et al. “Frequency Tuning of Piezoelectric Energy Harvesters by Magnetic Force.” Smart Materials and Structures, vol. 21, no. 3, 2012, p. 035019.","bibtex":"@article{Al-Ashtari_Hunstig_Hemsel_Sextro_2012, title={Frequency tuning of piezoelectric energy harvesters by magnetic force}, volume={21}, number={3}, journal={Smart Materials and Structures}, author={Al-Ashtari, Waleed and Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}, year={2012}, pages={035019} }","short":"W. Al-Ashtari, M. Hunstig, T. Hemsel, W. Sextro, Smart Materials and Structures 21 (2012) 035019.","ama":"Al-Ashtari W, Hunstig M, Hemsel T, Sextro W. Frequency tuning of piezoelectric energy harvesters by magnetic force. Smart Materials and Structures. 2012;21(3):035019.","apa":"Al-Ashtari, W., Hunstig, M., Hemsel, T., & Sextro, W. (2012). Frequency tuning of piezoelectric energy harvesters by magnetic force. Smart Materials and Structures, 21(3), 035019.","chicago":"Al-Ashtari, Waleed, Matthias Hunstig, Tobias Hemsel, and Walter Sextro. “Frequency Tuning of Piezoelectric Energy Harvesters by Magnetic Force.” Smart Materials and Structures 21, no. 3 (2012): 035019.","ieee":"W. Al-Ashtari, M. Hunstig, T. Hemsel, and W. Sextro, “Frequency tuning of piezoelectric energy harvesters by magnetic force,” Smart Materials and Structures, vol. 21, no. 3, p. 035019, 2012."},"user_id":"55222"},{"volume":23,"page":"15-23","_id":"9782","date_updated":"2022-01-06T07:04:20Z","issue":"1","publication":"Journal of Intelligent Material Systems and Structures","quality_controlled":"1","date_created":"2019-05-13T13:17:37Z","status":"public","year":"2012","type":"journal_article","language":[{"iso":"eng"}],"user_id":"55222","citation":{"mla":"Al-Ashtari, Waleed, et al. “Analytical Determination of Characteristic Frequencies and Equivalent Circuit Parameters of a Piezoelectric Bimorph.” Journal of Intelligent Material Systems and Structures, vol. 23, no. 1, 2012, pp. 15–23, doi:10.1177/1045389X11430742.","bibtex":"@article{Al-Ashtari_Hunstig_Hemsel_Sextro_2012, title={Analytical determination of characteristic frequencies and equivalent circuit parameters of a piezoelectric bimorph}, volume={23}, DOI={10.1177/1045389X11430742}, number={1}, journal={Journal of Intelligent Material Systems and Structures}, author={Al-Ashtari, Waleed and Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}, year={2012}, pages={15–23} }","short":"W. Al-Ashtari, M. Hunstig, T. Hemsel, W. Sextro, Journal of Intelligent Material Systems and Structures 23 (2012) 15–23.","apa":"Al-Ashtari, W., Hunstig, M., Hemsel, T., & Sextro, W. (2012). Analytical determination of characteristic frequencies and equivalent circuit parameters of a piezoelectric bimorph. Journal of Intelligent Material Systems and Structures, 23(1), 15–23. https://doi.org/10.1177/1045389X11430742","ama":"Al-Ashtari W, Hunstig M, Hemsel T, Sextro W. Analytical determination of characteristic frequencies and equivalent circuit parameters of a piezoelectric bimorph. Journal of Intelligent Material Systems and Structures. 2012;23(1):15-23. doi:10.1177/1045389X11430742","chicago":"Al-Ashtari, Waleed, Matthias Hunstig, Tobias Hemsel, and Walter Sextro. “Analytical Determination of Characteristic Frequencies and Equivalent Circuit Parameters of a Piezoelectric Bimorph.” Journal of Intelligent Material Systems and Structures 23, no. 1 (2012): 15–23. https://doi.org/10.1177/1045389X11430742.","ieee":"W. Al-Ashtari, M. Hunstig, T. Hemsel, and W. Sextro, “Analytical determination of characteristic frequencies and equivalent circuit parameters of a piezoelectric bimorph,” Journal of Intelligent Material Systems and Structures, vol. 23, no. 1, pp. 15–23, 2012."},"department":[{"_id":"151"}],"author":[{"last_name":"Al-Ashtari","first_name":"Waleed","full_name":"Al-Ashtari, Waleed"},{"last_name":"Hunstig","first_name":"Matthias","full_name":"Hunstig, Matthias"},{"first_name":"Tobias","full_name":"Hemsel, Tobias","last_name":"Hemsel","id":"210"},{"id":"21220","last_name":"Sextro","first_name":"Walter","full_name":"Sextro, Walter"}],"title":"Analytical determination of characteristic frequencies and equivalent circuit parameters of a piezoelectric bimorph","abstract":[{"lang":"eng","text":"Piezoelectric structures are nowadays used in many different applications. A better understanding of the influence of material properties and geometrical design on the performance of these structures helps to develop piezoelectric structures specifically designed for their application. Different equivalent circuits have been introduced in the literature to investigate the behaviour of piezoelectric transducers. The model parameters are usually determined from measurements covering the characteristic frequencies of the piezoelectric transducer. This article introduces an analytical technique for calculating the mechanical and electrical equivalent system parameters and characteristic frequencies based on material properties and geometry for a cantilever bimorph structure. The model is validated by measurements using a cantilever bimorph and fits the experimental results better than previous models. The model gives a full set of piezoelectric transducer parameters and is therefore well suited for further theoretical investigations of piezoelectric transducers for different applications. The results also show that even small manufacturing tolerances have a considerable effect on the system parameters and characteristic frequencies. This might lead to intolerable deviations, especially in dynamic applications and should be avoided by careful design and production."}],"intvolume":" 23","doi":"10.1177/1045389X11430742"},{"language":[{"iso":"eng"}],"type":"conference","publication_identifier":{"issn":["1948-5719"]},"year":"2012","status":"public","date_created":"2019-05-13T13:18:49Z","publication":"Ultrasonics Symposium (IUS), 2012 IEEE International","quality_controlled":"1","date_updated":"2022-01-06T07:04:20Z","page":"1141-1144","_id":"9783","abstract":[{"lang":"eng","text":"To optimize the ultrasound irradiation for cavitation based ultrasound applications like sonochemistry or ultrasound cleaning, the correlation between cavitation intensity and the resulting effect on the process is of interest. Furthermore, changing conditions like temperature and pressure result in varying acoustic properties of the liquid. That might necessitate an adaption of the ultrasound irradiation. To detect such changes during operation, process monitoring is desired. Labor intensive processes, that might be carried out for several hours, also require process monitoring to increase their reliability by detection of changes or malfunctions during operation. In some applications cavitation detection and monitoring can be achieved by the application of sensors in the sound field. Though the application of sensors is possible, this necessitates modifications on the system and the sensor might disturb the sound field. In other applications harsh, process conditions prohibit the application of sensors in the sound field. Therefore alternative techniques for cavitation detection and monitoring are desired. The applicability of an external microphone and a self-sensing ultrasound transducer for cavitation detection were experimentally investigated. Both methods were found to be suitable and easily applicable."}],"doi":"10.1109/ULTSYM.2012.0284","title":"Non-perturbing cavitation detection / monitoring in sonochemical reactors","author":[{"last_name":"Bornmann","full_name":"Bornmann, Peter","first_name":"Peter"},{"id":"210","last_name":"Hemsel","first_name":"Tobias","full_name":"Hemsel, Tobias"},{"last_name":"Sextro","id":"21220","first_name":"Walter","full_name":"Sextro, Walter"},{"full_name":"Maeda, Takafumi","first_name":"Takafumi","last_name":"Maeda"},{"last_name":"Morita","full_name":"Morita, Takeshi","first_name":"Takeshi"}],"department":[{"_id":"151"}],"citation":{"ieee":"P. Bornmann, T. Hemsel, W. Sextro, T. Maeda, and T. Morita, “Non-perturbing cavitation detection / monitoring in sonochemical reactors,” in Ultrasonics Symposium (IUS), 2012 IEEE International, 2012, pp. 1141–1144.","chicago":"Bornmann, Peter, Tobias Hemsel, Walter Sextro, Takafumi Maeda, and Takeshi Morita. “Non-Perturbing Cavitation Detection / Monitoring in Sonochemical Reactors.” In Ultrasonics Symposium (IUS), 2012 IEEE International, 1141–44, 2012. https://doi.org/10.1109/ULTSYM.2012.0284.","apa":"Bornmann, P., Hemsel, T., Sextro, W., Maeda, T., & Morita, T. (2012). Non-perturbing cavitation detection / monitoring in sonochemical reactors. In Ultrasonics Symposium (IUS), 2012 IEEE International (pp. 1141–1144). https://doi.org/10.1109/ULTSYM.2012.0284","ama":"Bornmann P, Hemsel T, Sextro W, Maeda T, Morita T. Non-perturbing cavitation detection / monitoring in sonochemical reactors. In: Ultrasonics Symposium (IUS), 2012 IEEE International. ; 2012:1141-1144. doi:10.1109/ULTSYM.2012.0284","short":"P. Bornmann, T. Hemsel, W. Sextro, T. Maeda, T. Morita, in: Ultrasonics Symposium (IUS), 2012 IEEE International, 2012, pp. 1141–1144.","bibtex":"@inproceedings{Bornmann_Hemsel_Sextro_Maeda_Morita_2012, title={Non-perturbing cavitation detection / monitoring in sonochemical reactors}, DOI={10.1109/ULTSYM.2012.0284}, booktitle={Ultrasonics Symposium (IUS), 2012 IEEE International}, author={Bornmann, Peter and Hemsel, Tobias and Sextro, Walter and Maeda, Takafumi and Morita, Takeshi}, year={2012}, pages={1141–1144} }","mla":"Bornmann, Peter, et al. “Non-Perturbing Cavitation Detection / Monitoring in Sonochemical Reactors.” Ultrasonics Symposium (IUS), 2012 IEEE International, 2012, pp. 1141–44, doi:10.1109/ULTSYM.2012.0284."},"keyword":["cavitation","chemical reactors","microphones","process monitoring","reliability","ultrasonic applications","ultrasonic waves","acoustic properties","cavitation based ultrasound applications","cavitation intensity","change detection reliability","external microphone","malfunction detection reliability","nonperturbing cavitation detection","nonperturbing cavitation monitoring","process monitoring","self-sensing ultrasound transducer","sonochemical reactors","sonochemistry","ultrasound cleaning","ultrasound irradiation","Acoustics","Liquids","Monitoring","Sensors","Sonar equipment","Transducers","Ultrasonic imaging"],"user_id":"55222"},{"date_updated":"2022-01-06T07:04:20Z","popular_science":"1","_id":"9787","page":"38-60","status":"public","year":"2012","type":"conference","language":[{"iso":"eng"}],"publication":"8. Tag des Fahrwerks, Aachen, 2012","date_created":"2019-05-13T13:25:59Z","department":[{"_id":"151"}],"user_id":"55222","citation":{"short":"S. Kohl, W. Sextro, A. Zuber, in: 8. Tag Des Fahrwerks, Aachen, 2012, Institut für Kraftfahrzeuge, RWTH Aachen University in Aachen, 2012, pp. 38–60.","mla":"Kohl, Sergej, et al. “Benteler Vehicle Dynamics -- Fahrdynamikentwicklung Basierend Auf Einer Neuen Auslegungstheorie.” 8. Tag Des Fahrwerks, Aachen, 2012, 2012, pp. 38–60.","bibtex":"@inproceedings{Kohl_Sextro_Zuber_2012, place={Institut für Kraftfahrzeuge, RWTH Aachen University in Aachen}, title={Benteler Vehicle Dynamics -- Fahrdynamikentwicklung basierend auf einer neuen Auslegungstheorie}, booktitle={8. Tag des Fahrwerks, Aachen, 2012}, author={Kohl, Sergej and Sextro, Walter and Zuber, Armin}, year={2012}, pages={38–60} }","chicago":"Kohl, Sergej, Walter Sextro, and Armin Zuber. “Benteler Vehicle Dynamics -- Fahrdynamikentwicklung Basierend Auf Einer Neuen Auslegungstheorie.” In 8. Tag Des Fahrwerks, Aachen, 2012, 38–60. Institut für Kraftfahrzeuge, RWTH Aachen University in Aachen, 2012.","ieee":"S. Kohl, W. Sextro, and A. Zuber, “Benteler Vehicle Dynamics -- Fahrdynamikentwicklung basierend auf einer neuen Auslegungstheorie,” in 8. Tag des Fahrwerks, Aachen, 2012, 2012, pp. 38–60.","apa":"Kohl, S., Sextro, W., & Zuber, A. (2012). Benteler Vehicle Dynamics -- Fahrdynamikentwicklung basierend auf einer neuen Auslegungstheorie. In 8. Tag des Fahrwerks, Aachen, 2012 (pp. 38–60). Institut für Kraftfahrzeuge, RWTH Aachen University in Aachen.","ama":"Kohl S, Sextro W, Zuber A. Benteler Vehicle Dynamics -- Fahrdynamikentwicklung basierend auf einer neuen Auslegungstheorie. In: 8. Tag Des Fahrwerks, Aachen, 2012. Institut für Kraftfahrzeuge, RWTH Aachen University in Aachen; 2012:38-60."},"place":"Institut für Kraftfahrzeuge, RWTH Aachen University in Aachen","author":[{"last_name":"Kohl","full_name":"Kohl, Sergej","first_name":"Sergej"},{"full_name":"Sextro, Walter","first_name":"Walter","last_name":"Sextro","id":"21220"},{"full_name":"Zuber, Armin","first_name":"Armin","last_name":"Zuber"}],"title":"Benteler Vehicle Dynamics -- Fahrdynamikentwicklung basierend auf einer neuen Auslegungstheorie"}]