{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T23:29:06Z","timestamp":1773271746098,"version":"3.50.1"},"reference-count":47,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,10,8]],"date-time":"2022-10-08T00:00:00Z","timestamp":1665187200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"High-Performance Center Mass Personalization in Stuttgart","award":["32-7542.2-500\/55\/3"],"award-info":[{"award-number":["32-7542.2-500\/55\/3"]}]},{"name":"High-Performance Center Mass Personalization in Stuttgart","award":["EXC 2075\u2014390740016"],"award-info":[{"award-number":["EXC 2075\u2014390740016"]}]},{"name":"Ministry of Science, Research and the Arts BadenW\u00fcrttemberg","award":["32-7542.2-500\/55\/3"],"award-info":[{"award-number":["32-7542.2-500\/55\/3"]}]},{"name":"Ministry of Science, Research and the Arts BadenW\u00fcrttemberg","award":["EXC 2075\u2014390740016"],"award-info":[{"award-number":["EXC 2075\u2014390740016"]}]},{"name":"Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)","award":["32-7542.2-500\/55\/3"],"award-info":[{"award-number":["32-7542.2-500\/55\/3"]}]},{"name":"Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)","award":["EXC 2075\u2014390740016"],"award-info":[{"award-number":["EXC 2075\u2014390740016"]}]},{"name":"Stuttgart Center for Simulation Science (SimTech)","award":["32-7542.2-500\/55\/3"],"award-info":[{"award-number":["32-7542.2-500\/55\/3"]}]},{"name":"Stuttgart Center for Simulation Science (SimTech)","award":["EXC 2075\u2014390740016"],"award-info":[{"award-number":["EXC 2075\u2014390740016"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Robotics"],"abstract":"<jats:p>Exoskeletons are powerful tools for aiding humans with pathological conditions, in dangerous environments or in manually exhausting tasks. Typically, they are designed for specific maximum scenarios without taking into account the diversity of tasks and the individuality of the user. To address this discrepancy, a framework was developed for personalizing an exoskeleton by scaling the components, especially the electrical machine, based on different simulated human muscle forces. The main idea was to scale a numerical arm model based on body mass and height to predict different movements representing both manual labor and daily activities. The predicted torques necessary to produce these movements were then used to generate a load\/performance cycle for the power unit design. Considering these torques, main operation points of this load cycle were defined and a reference power unit was scaled and optimized. Therefore, a scalability model for an electrical machine is introduced. This individual adaptation and scaling of the power unit for different users leads to a better performance and a lighter design.<\/jats:p>","DOI":"10.3390\/robotics11050107","type":"journal-article","created":{"date-parts":[[2022,10,10]],"date-time":"2022-10-10T03:07:28Z","timestamp":1665371248000},"page":"107","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Design and Scaling of Exoskeleton Power Units Considering Load Cycles of Humans"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4545-0665","authenticated-orcid":false,"given":"Marcel","family":"Waldhof","sequence":"first","affiliation":[{"name":"Institute of Electrical Energy Conversion, University of Stuttgart, 70569 Stuttgart, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2820-5791","authenticated-orcid":false,"given":"Isabell","family":"Wochner","sequence":"additional","affiliation":[{"name":"Institute of Modelling and Simulation of Biomechanical Systems, University of Stuttgart, 70569 Stuttgart, Germany"}]},{"given":"Katrin","family":"Stollenmaier","sequence":"additional","affiliation":[{"name":"Institute of Modelling and Simulation of Biomechanical Systems, University of Stuttgart, 70569 Stuttgart, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0978-7447","authenticated-orcid":false,"given":"Nejila","family":"Parspour","sequence":"additional","affiliation":[{"name":"Institute of Electrical Energy Conversion, University of Stuttgart, 70569 Stuttgart, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7768-8961","authenticated-orcid":false,"given":"Syn","family":"Schmitt","sequence":"additional","affiliation":[{"name":"Institute of Modelling and Simulation of Biomechanical Systems, University of Stuttgart, 70569 Stuttgart, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2022,10,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"475","DOI":"10.1016\/j.ergon.2014.03.008","article-title":"Ergonomic contribution of ABLE exoskeleton in automotive industry","volume":"44","author":"Sylla","year":"2014","journal-title":"Int. J. Ind. Ergon."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"804","DOI":"10.1177\/1541931218621184","article-title":"Evaluation of an adjustable support shoulder exoskeleton on static and dynamic overhead tasks","volume":"62","author":"Poon","year":"2018","journal-title":"Proc. Hum. Factors Ergon. Soc. Annu. Meet."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1080\/24725838.2018.1563010","article-title":"A Field Evaluation of Arm-Support Exoskeletons for Overhead Work Applications in Automotive Assembly","volume":"7","author":"Smets","year":"2019","journal-title":"IISE Trans. Occup. Ergon. Hum. Factors"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Gull, M.A., Bai, S., and Bak, T. (2020). A review on design of upper limb exoskeletons. Robotics, 9.","DOI":"10.3390\/robotics9010016"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"157096","DOI":"10.1155\/2014\/157096","article-title":"Optimal design of a 3-DOF cable-driven upper arm exoskeleton","volume":"6","author":"Shao","year":"2014","journal-title":"Adv. Mech. Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/j.robot.2016.12.012","article-title":"A human-centered design optimization approach for robotic exoskeletons through biomechanical simulation","volume":"91","author":"Zhou","year":"2017","journal-title":"Robot. Auton. Syst."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"967","DOI":"10.1163\/156855306778394030","article-title":"Design of an electrically actuated lower extremity exoskeleton","volume":"20","author":"Zoss","year":"2006","journal-title":"Adv. Robot."},{"key":"ref_8","first-page":"381","article-title":"Actuation Requirements for Assistive Exoskeletons: Exploiting Knowledge of Task Dynamics","volume":"Volume 22","author":"Carrozza","year":"2019","journal-title":"Wearable Robotics: Challenges and Trends"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2053","DOI":"10.1109\/TNSRE.2020.3010829","article-title":"Actuation Selection for Assistive Exoskeletons: Matching Capabilities to Task Requirements","volume":"28","author":"Calanca","year":"2020","journal-title":"IEEE Trans. Neural Syst. Rehabil. Eng. A Publ. IEEE Eng. Med. Biol. Soc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1504\/IJVD.2013.050849","article-title":"Magnetic and thermal scaling of electric machines","volume":"61","author":"Pries","year":"2013","journal-title":"Int. J. Veh. Des."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1109\/20.559962","article-title":"One kind of scaling relations on electromechanical systems","volume":"33","author":"Hsieh","year":"1997","journal-title":"IEEE Trans. Magn."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4435","DOI":"10.1109\/TIA.2015.2451094","article-title":"Finite-Element-Based Computationally Efficient Scalable Electric Machine Model Suitable for Electrified Powertrain Simulation and Optimization","volume":"51","author":"Zhou","year":"2015","journal-title":"IEEE Trans. Ind. Appl."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Stipetic, S., Zarko, D., and Popescu, M. (April, January 31). Scaling laws for synchronous permanent magnet machines. Proceedings of the 2015 Tenth International Conference on Ecological Vehicles and Renewable Energies (EVER), Monte Carlo, Monaco.","DOI":"10.1109\/EVER.2015.7113006"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Seok, S., Wang, A., Otten, D., and Kim, S. (2012, January 7\u201312). Actuator design for high force proprioceptive control in fast legged locomotion. Proceedings of the 2012 IEEE\/RSJ International Conference on Intelligent Robots and Systems, Vilamoura-Algarve, Portugal.","DOI":"10.1109\/IROS.2012.6386252"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Wrobel, R., and Mecrow, B. (2019, January 22\u201323). Additive Manufacturing in Construction of Electrical Machines\u2014A Review. Proceedings of the 2019 IEEE Workshop on Electrical Machines Design, Control and Diagnosis (WEMDCD), Athens, Greece.","DOI":"10.1109\/WEMDCD.2019.8887765"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Tiismus, H., Kallaste, A., Vaimann, T., Rassolkin, A., and Belahcen, A. (July, January 29). Technologies for Additive Manufacturing of Electrical Machines. Proceedings of the 2019 20th International Conference of Young Specialists on Micro\/Nanotechnologies and Electron Devices (EDM), Erlagol, Russia.","DOI":"10.1109\/EDM.2019.8823462"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Kallaste, A., Vaimann, T., and Rassalkin, A. (2018, January 12\u201313). Additive Design Possibilities of Electrical Machines. Proceedings of the 2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON), Riga, Latvia.","DOI":"10.1109\/RTUCON.2018.8659828"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1257","DOI":"10.1109\/TASE.2015.2466634","article-title":"Control of Upper-Limb Power-Assist Exoskeleton Using a Human-Robot Interface Based on Motion Intention Recognition","volume":"12","author":"Huang","year":"2015","journal-title":"IEEE Trans. Autom. Sci. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1186\/1475-925X-7-27","article-title":"Interaction torque contributes to planar reaching at slow speed","volume":"7","author":"Yamasaki","year":"2008","journal-title":"Biomed. Eng. Online"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2342","DOI":"10.1152\/jn.00148.2016","article-title":"The duration of reaching movement is longer than predicted by minimum variance","volume":"116","author":"Wang","year":"2016","journal-title":"J. Neurophysiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"308","DOI":"10.3389\/fbioe.2020.00308","article-title":"Predicting Perturbed Human Arm Movements in a Neuro-Musculoskeletal Model to Investigate the Muscular Force Response","volume":"8","author":"Stollenmaier","year":"2020","journal-title":"Front. Bioeng. Biotechnol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1007\/s00422-007-0160-6","article-title":"High-frequency oscillations as a consequence of neglected serial damping in Hill-type muscle models","volume":"97","author":"Schmitt","year":"2007","journal-title":"Biol. Cybern."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1531","DOI":"10.1016\/j.jbiomech.2014.02.009","article-title":"Hill-type muscle model with serial damping and eccentric force-velocity relation","volume":"47","author":"Haeufle","year":"2014","journal-title":"J. Biomech."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.mbs.2019.02.004","article-title":"Tailoring anatomical muscle paths: A sheath-like solution for muscle routing in musculoskeletal computer models","volume":"311","author":"Hammer","year":"2019","journal-title":"Math. Biosci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1007\/BF00337268","article-title":"A myocybernetic control model of skeletal muscle","volume":"25","author":"Hatze","year":"1977","journal-title":"Biol. Cybern."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Pankoke, S., and Siefert, A. (2007). Virtual Simulation of Static and Dynamic Seating Comfort in the Development Process of Automobiles and Automotive Seats: Application of Finite-Element-Occupant-Model CASIMIR, SAE International.","DOI":"10.4271\/2007-01-2459"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"S32","DOI":"10.1080\/15389588.2019.1637518","article-title":"Evaluation of finite element human body models for use in a standardized protocol for pedestrian safety assessment","volume":"20","author":"Decker","year":"2019","journal-title":"Traffic Inj. Prev."},{"key":"ref_28","unstructured":"Pak, W. (2019). Development and Validation of Human Body Finite Element Models for Pedestrian Protection. [Ph.D. Thesis, Virginia Tech]."},{"key":"ref_29","unstructured":"(2022, August 24). DIN e.V. (publ.) (DIN 33402-2:2005-12, 2005): Ergonomics\u2014Human Body Dimensions, Part 2: Values. Available online: https:\/\/www.beuth.de\/en\/standard\/din-33402-2\/84092742."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Winter, D.A. (2009). Biomechanics and Motor Control of Human Movement, John Wiley & Sons.","DOI":"10.1002\/9780470549148"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1016\/j.jbiomech.2013.12.002","article-title":"Relationships of 35 lower limb muscles to height and body mass quantified using MRI","volume":"47","author":"Handsfield","year":"2014","journal-title":"J. Biomech."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1688","DOI":"10.1523\/JNEUROSCI.05-07-01688.1985","article-title":"The coordination of arm movements: An experimentally confirmed mathematical model","volume":"5","author":"Flash","year":"1985","journal-title":"J. Neurosci."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Stollenmaier, K., Rist, I.S., Izzi, F., and Haeufle, D.F. (December, January 29). Simulating the response of a neuro-musculoskeletal model to assistive forces: Implications for the design of wearables compensating for motor control deficits. Proceedings of the 2020 8th IEEE RAS\/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob), New York, NY, USA.","DOI":"10.1109\/BioRob49111.2020.9224411"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1007\/BF00236850","article-title":"Role of agonist and antagonist muscles in fast arm movements in man","volume":"63","author":"Wierzbicka","year":"1986","journal-title":"Exp. Brain Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2898","DOI":"10.1152\/jn.00983.2005","article-title":"Is equilibrium point control feasible for fast goal-directed single-joint movements?","volume":"95","author":"Kistemaker","year":"2006","journal-title":"J. Neurophysiol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Gunther, S., Ulbrich, S., and Hofmann, W. (2014, January 18\u201320). Driving cycle-based design optimization of interior permanent magnet synchronous motor drives for electric vehicle application. Proceedings of the International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), Ischia, Italy.","DOI":"10.1109\/SPEEDAM.2014.6872108"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1395","DOI":"10.1109\/TTE.2019.2950869","article-title":"Fundamental Evaluation of Data Clustering Approaches for Driving Cycle-Based Machine Design Optimization","volume":"5","author":"Salameh","year":"2019","journal-title":"IEEE Trans. Transp. Electrif."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1109\/TPAMI.1984.4767478","article-title":"K-means-type algorithms: A generalized convergence theorem and characterization of local optimality","volume":"6","author":"Selim","year":"1984","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Waldhof, M., Echle, A., and Parspour, N. (2019, January 12\u201315). A Novel Drive Train Concept for Personalized Upper Body Exoskeletons with a Multiphase Axial Flux Machine. Proceedings of the 2019 IEEE International Electric Machines & Drives Conference (IEMDC), San Diego, CA, USA.","DOI":"10.1109\/IEMDC.2019.8785412"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Keller, M., M\u00fcller, S., and Parspour, N. (2016, January 22\u201324). Design of a transverse flux machine as joint drive for an articulated six-axis robot arm. Proceedings of the 2016 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), Capri, Italy.","DOI":"10.1109\/SPEEDAM.2016.7525850"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1115\/1.4036538","article-title":"Optimal Transmission Ratio Selection for Electric Motor Driven Actuators With Known Output Torque and Motion Trajectories","volume":"139","author":"Bartlett","year":"2017","journal-title":"J. Dyn. Syst. Meas. Control"},{"key":"ref_42","unstructured":"Hanselman, D.C. (1994). Brushless Permanent-Magnet Motor Design, McGraw-Hill."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Gieras, J.F., Wang, R.J., and Kamper, M.J. (2008). Axial Flux Permanent Magnet Brushless Machines, Springer. [2nd ed.].","DOI":"10.1007\/978-1-4020-8227-6"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1495","DOI":"10.1109\/TIA.2008.2002183","article-title":"Analysis and Performance of Axial Flux Permanent-Magnet Machine with Air-Cored Nonoverlapping Concentrated Stator Windings","volume":"44","author":"Kamper","year":"2008","journal-title":"IEEE Trans. Ind. Appl."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Rosu, M., Zhou, P., Lin, D., Ionel, D.M., Popescu, M., Blaabjerg, F., Rallabandi, V., and Staton, D. (2018). Multiphysics Simulation by Design for Electrical Machines, Power Electronics and Drives, Wiley.","DOI":"10.1002\/9781119103462"},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Waldhof, M., and Parspour, N. (2020, January 23\u201326). Torque Ripple Minimization in Exoskeleton Drives with Multiphase Electrical Machines by Current Harmonic Injection. Proceedings of the 2020 International Conference on Electrical Machines (ICEM), Gothenburg, Sweden.","DOI":"10.1109\/ICEM49940.2020.9270848"},{"key":"ref_47","unstructured":"(2022, March 21). Maxon-Motor-GmbH. Available online: https:\/\/www.maxongroup.de\/maxon\/view\/category\/motor?etcc_cu=onsite&etcc_med_onsite=Product&etcc_cmp_onsite=ECXSPEEDProgramm&etcc_plc=Overview-Page-brushless-DC-Motors&etcc_var=[de]#de#_d_&target=filter&filterCategory=ECX."}],"container-title":["Robotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2218-6581\/11\/5\/107\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:48:16Z","timestamp":1760143696000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2218-6581\/11\/5\/107"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,10,8]]},"references-count":47,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2022,10]]}},"alternative-id":["robotics11050107"],"URL":"https:\/\/doi.org\/10.3390\/robotics11050107","relation":{},"ISSN":["2218-6581"],"issn-type":[{"value":"2218-6581","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,10,8]]}}}