@inproceedings{WittigRuettersBragard2024,
  author    = {Wittig, M. and R{\"u}tters, Ren{\´e} and Bragard, Michael},
  title     = {Application of RL in control systems using the example of a rotatory inverted pendulum},
  series = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation},
  booktitle = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation},
  editor    = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and Schwarz, Andr{\´e}},
  publisher = {le-tex publishing services GmbH},
  address   = {Leipzig},
  isbn      = {978-3-910103-02-3},
  doi       = {10.33968/2024.53},
  pages     = {241 -- 248},
  year      = {2024},
  abstract  = {In this paper, the use of reinforcement learning (RL) in control systems is investigated using a rotatory inverted pendulum as an example. The control behavior of an RL controller is compared to that of traditional LQR and MPC controllers. This is done by evaluating their behavior under optimal conditions, their disturbance behavior, their robustness and their development process. All the investigated controllers are developed using MATLAB and the Simulink simulation environment and later deployed to a real pendulum model powered by a Raspberry Pi. The RL algorithm used is Proximal Policy Optimization (PPO). The LQR controller exhibits an easy development process, an average to good control behavior and average to good robustness. A linear MPC controller could show excellent results under optimal operating conditions. However, when subjected to disturbances or deviations from the equilibrium point, it showed poor performance and sometimes instable behavior. Employing a nonlinear MPC Controller in real time was not possible due to the high computational effort involved. The RL controller exhibits by far the most versatile and robust control behavior. When operated in the simulation environment, it achieved a high control accuracy. When employed in the real system, however, it only shows average accuracy and a significantly greater performance loss compared to the simulation than the traditional controllers. With MATLAB, it is not yet possible to directly post-train the RL controller on the Raspberry Pi, which is an obstacle to the practical application of RL in a prototyping or teaching setting. Nevertheless, RL in general proves to be a flexible and powerful control method, which is well suited for complex or nonlinear systems where traditional controllers struggle.},
  language  = {en}
}
@inproceedings{SchifferBragard2019,
  author    = {Schiffer, Fabian and Bragard, Michael},
  title     = {Cascaded LQ and Field-Oriented Control of a Mobile Inverse Pendulum (Segway) with Permanent Magnet Synchronous Machines},
  series = {2019 20th International Conference on Research and Education in Mechatronics (REM)},
  booktitle = {2019 20th International Conference on Research and Education in Mechatronics (REM)},
  isbn      = {978-1-5386-9257-8},
  doi       = {10.1109/REM.2019.8744101},
  pages     = {1 -- 8},
  year      = {2019},
  language  = {en}
}
@inproceedings{RuettersWeinheimerBragard2018,
  author    = {R{\"u}tters, Ren{\´e} and Weinheimer, Marius and Bragard, Michael},
  title     = {Teaching Control Theory with a Simplified Helicopter Model and a Classroom Fitting Hardware Test-Bench},
  series = {2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)},
  booktitle = {2018 IEEE 59th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON)},
  isbn      = {978-1-5386-6903-7},
  doi       = {10.1109/RTUCON.2018.8659871},
  year      = {2018},
  language  = {en}
}
@inproceedings{OstkottePetersHueningetal.2022,
  author    = {Ostkotte, Sebastian and Peters, Constantin and H{\"u}ning, Felix and Bragard, Michael},
  title     = {Design, implementation and verification of an rotational incremental position encoder based on the magnetic Wiegand effect},
  series = {2022 ELEKTRO (ELEKTRO)},
  booktitle = {2022 ELEKTRO (ELEKTRO)},
  publisher = {IEEE},
  isbn      = {978-1-6654-6726-1},
  issn      = {2691-0616},
  doi       = {10.1109/ELEKTRO53996.2022.9803477},
  pages     = {6 Seiten},
  year      = {2022},
  abstract  = {This paper covers the use of the magnetic Wiegand effect to design an innovative incremental encoder. First, a theoretical design is given, followed by an estimation of the achievable accuracy and an optimization in open-loop operation. Finally, a successful experimental verification is presented. For this purpose, a permanent magnet synchronous machine is controlled in a field-oriented manner, using the angle information of the prototype.},
  language  = {en}
}
@inproceedings{NoetzoldUphuesWegeneretal.2012,
  author    = {N{\"o}tzold, K. and Uphues, A. and Wegener, R. and Soter, S. and Fink, K. and Bragard, Michael and Griessel, R.},
  title     = {Inverter based test setup for LVRT verification of a full-scale 2 MW wind power converter},
  series = {EPE Joint Wind Energy and T\&D Chapters Seminar : 28th and 29th of June 2012, in the Utzon Centre, Aalborg, Denmark ; papers, posters, presentations. - Session 2: Grid connection, compliance},
  booktitle = {EPE Joint Wind Energy and T\&D Chapters Seminar : 28th and 29th of June 2012, in the Utzon Centre, Aalborg, Denmark ; papers, posters, presentations. - Session 2: Grid connection, compliance},
  publisher = {EPE Association},
  address   = {Brussels},
  year      = {2012},
  language  = {en}
}
@inproceedings{NoetzoldUphuesWegeneretal.2013,
  author    = {N{\"o}tzold, K. and Uphues, A. and Wegener, R. and Fink, K. and Bragard, Michael and Griessel, R. and Soter, S.},
  title     = {Inverter based test setup for LVRT verification of a full-scale 2 MW wind power converter},
  series = {15th European Conference on Power Electronics and Applications (EPE), 2013 : 2 - 6 Sept. 2013, Lille, France / [EPE Association; PELS, IEEE Power Electronics Society]},
  booktitle = {15th European Conference on Power Electronics and Applications (EPE), 2013 : 2 - 6 Sept. 2013, Lille, France / [EPE Association; PELS, IEEE Power Electronics Society]},
  publisher = {IEEE},
  address   = {Piscataway, NJ},
  isbn      = {978-1-4799-0115-9 (Online-Ausg.)},
  doi       = {10.1109/EPE.2013.6634752},
  pages     = {1037 -- 1042},
  year      = {2013},
  language  = {en}
}
@misc{NoetzoldBragardFinketal.2014,
  author    = {N{\"o}tzold, K. and Bragard, Michael and Fink, K. and Griessel, R. and Wegener, R.},
  title     = {Cascaded H-bridge converter with transformer based cell power balancing in each voltage level : [Patentschrift]},
  publisher = {Europ{\"a}isches Patentamt / United States Patent and Trademark Office [u.a.]},
  address   = {Den Haag / Alexandria, VA},
  pages     = {16 S. : graph. Darst.},
  year      = {2014},
  language  = {en}
}
@inproceedings{KoellenspergerBragardPlumetal.2007,
  author    = {K{\"o}llensperger, P. and Bragard, Michael and Plum, T. and De Doncker, R. W.},
  title     = {The dual GCT : a new high-power device using optimized GCT technology},
  series = {Conference record of the 2007 IEEE Industry Applications Conference : 42. IAS annual meeting ; September 23 - 27, 2007, New Orleans, Louisiana, USA},
  booktitle = {Conference record of the 2007 IEEE Industry Applications Conference : 42. IAS annual meeting ; September 23 - 27, 2007, New Orleans, Louisiana, USA},
  publisher = {IEEE Operations Center},
  address   = {Piscataway, NJ},
  isbn      = {978-1-4244-1260-0 (Online)},
  doi       = {10.1109/07IAS.2007.76},
  pages     = {358 -- 365},
  year      = {2007},
  language  = {en}
}
@article{KoellenspergerBragardPlumetal.2009,
  author    = {K{\"o}llensperger, P. and Bragard, Michael and Plum, T. and De Doncker, R. W.},
  title     = {The dual GCT : new high-power device using optimized GCT technology},
  series = {IEEE transactions on industry applications},
  volume    = {45},
  journal   = {IEEE transactions on industry applications},
  number    = {5},
  issn      = {0093-9994},
  doi       = {10.1109/TIA.2009.2027364},
  pages     = {1754 -- 1762},
  year      = {2009},
  language  = {en}
}
@article{KowalewskiBragardHueningetal.2023,
  author    = {Kowalewski, Paul and Bragard, Michael and H{\"u}ning, Felix and De Doncker, Rik W.},
  title     = {An inexpensive Wiegand-sensor-based rotary encoder without rotating magnets for use in electrical drives},
  series = {IEEE Transactions on Instrumentation and Measurement},
  journal   = {IEEE Transactions on Instrumentation and Measurement},
  publisher = {IEEE},
  issn      = {0018-9456 (Print)},
  doi       = {10.1109/TIM.2023.3326166},
  pages     = {10 Seiten},
  year      = {2023},
  abstract  = {This paper introduces an inexpensive Wiegand-sensor-based rotary encoder that avoids rotating magnets and is suitable for electrical-drive applications. So far, Wiegand-sensor-based encoders usually include a magnetic pole wheel with rotating permanent magnets. These encoders combine the disadvantages of an increased magnet demand and a limited maximal speed due to the centripetal force acting on the rotating magnets. The proposed approach reduces the total demand of permanent magnets drastically. Moreover, the rotating part is manufacturable from a single piece of steel, which makes it very robust and cheap. This work presents the theoretical operating principle of the proposed approach and validates its benefits on a hardware prototype. The presented proof-of-concept prototype achieves a mechanical resolution of 4.5 ° by using only 4 permanent magnets, 2Wiegand sensors and a rotating steel gear wheel with 20 teeth.},
  language  = {en}
}