04.10.2019
BURG

Benchmarks for Understanding Grasping

In the BURG Project we set out to boost grasping research by focusing on complete tasks and the related object manipulation constraints. In doing so, we need to move from objects to parts, since object parts facilitate the interpretable usage of objects. Parts are essential to know how and where the gripper can grasp given the constraints imposed by the task, e.g., pouring from a container implies grasping from the side. The novelty will come from learning to predict plausible grasps and to link grasps to the parts responsible for selecting each of them. In BURG we will boost grasping research by focusing on complete tasks and the related object manipulation constraints. In doing so, we need to move from objects to parts (Fig. 1), since object parts facilitate the interpretable usage of objects. Parts are essential to know how and where the gripper can grasp given the constraints imposed by the task, e.g., pouring from a container implies grasping from the side. The novelty will come from learning to predict plausible grasps and to link grasps to the parts responsible for selecting each of them.

 

FUNDING:

The project is funded by FWF – Austrian Science Foundation & CHIST-ERA.

  25.06.2019
Aktive Turbulenzunterdrückung für Flugzeuge – SmartWings

Atmosphärische Turbulenzen stellen für die Luftfahrt ein ungelöstes Problem dar, das Wirtschaftlichkeit, Sicherheit und Komfort beeinträchtigt. Aktuelle Bestrebungen, Turbulenzen genauer vorherzusagen und frühzeitig auszuweichen, führen zu höherem Treibstoffverbrauch und CO₂-Ausstoß sowie zu verringertem Verkehrsvolumen.

Ziel

Zukünftig soll es möglich sein, Turbulenzen direkt und zuverlässig zu durchfliegen. Dazu werden im Forschungsprojekt SmartWings an der TU Wien Methoden und Technologien untersucht, die Störeffekte von Turbulenzen, wie beispielsweise Vertikalbeschleunigungen, um mehr als 80% reduzieren können.

Lösungsansatz

Intelligente Flügelstrukturen, die Turbulenzen vor dem Flügel messen und aktiv ihre Form anpassen, können Störeffekte von Turbulenzen im Flug unterdrücken. Aus den Messdaten optimale Flugsteuerausgaben zu berechnen, ist eine besondere regelungstechnische Herausforderung. Sie wird durch eine Kombination modellbasierter Feedforward- und Feedbackregelung gelöst.

Hochdynamische Auftriebsregelung: Durch die Anwendung von direktem Auftrieb (Direct Lift Control) kann der Flügelauftrieb sehr schnell variiert werden. Dabei verhindert ein neuartiges  Steuerungsverfahren eine sekundäre Anstellwinkelschwingung und erhöht damit den erzielbaren Effekt des Auftriebes erheblich.

Phasenrichtige Kompensation: Durch den Einsatz antizipierender Sensorik, wie beispielsweise Druckmessungen vor dem Flügel oder Wind-LiDAR, ist es möglich systembedingte Zeitverzögerungen zu kompensieren und die Störungen präzise, im richtigen Moment zu kompensieren.

Adaptive Strukturen: Neuartige Materialien und Fertigungsmethoden ermöglichen den Einsatz adaptiver Flügelstrukturen (Morphing Wings), um die Flügelform ganz gezielt auf das externe Strömungsfeld anzupassen.

Publikationen

Zeitschriftenbeträge

• A. Galffy, R. Gaggl, R. Mühlbacher, D. Frank, J. Schlarp, and G. Schitter, Turbulence load prediction for manned and unmanned aircraft by means of anticipating differential pressure measurements, CEAS Aeronautical Journal, vol. 12, 2021.
  [BibTex] [Download]

  @article{TUW-292332,
  author = {Galffy, Andras and Gaggl, Rainer and M{\"u}hlbacher, Robert and Frank, Daniel and Schlarp, Johannes and Schitter, Georg},
  title = {Turbulence load prediction for manned and unmanned aircraft by means of anticipating differential pressure measurements},
  journal = {CEAS Aeronautical Journal},
  year = {2021},
  volume = {12},
  doi = {10.1007/s13272-021-00512-y},
  keywords = {atmospheric turbulence, disturbance prediction, turbulence suppression, gust load alleviation}
  }

• A. Galffy, M. Böck, and A. Kugi, Nonlinear 3D path following control of a fixed-wing aircraft based on acceleration control, Control Engineering Practice, vol. 86, p. 56–69, 2019.
  [BibTex] [Download]

  @article{TUW-278869,
  author = {Galffy, Andras and B{\"o}ck, Martin and Kugi, Andreas},
  title = {Nonlinear 3D path following control of a fixed-wing aircraft based on acceleration control},
  journal = {Control Engineering Practice},
  year = {2019},
  volume = {86},
  pages = {56--69},
  doi = {10.1016/j.conengprac.2019.03.006}
  }

Konferenzbeiträge

• A. Galffy, J. Schlarp, D. Frank, R. Mühlbacher, and G. Schitter, Turbulence prediction for aircraft by means of high-dynamic differential pressure measurements, in Proceedings of the Aerospace Europe Conference AEC2020, 2020.
  [BibTex] [Download]

  @inproceedings{TUW-292322,
  author = {Galffy, Andras and Schlarp, Johannes and Frank, Daniel and M{\"u}hlbacher, Robert and Schitter, Georg},
  title = {Turbulence prediction for aircraft by means of high-dynamic differential pressure measurements},
  booktitle = {Proceedings of the Aerospace Europe Conference AEC2020},
  year = {2020},
  keywords = {atmospheric turbulence, disturbance prediction, turbulence suppression, gust load alleviation},
  note = {Vortrag: Aerospace Europe Conference AEC2020, Bordeaux, France; 2020-02-25 -- 2020-02-28}
  }

• A. Galffy, F. Car, and G. Schitter, Calibration and flight test of a 3D printed 5-hole probe for high-dynamic wind measurements for UAV, in Proceedings of the International Workshop on Research, Education and Development on Unmanned Aerial Systems, 2019.
  [BibTex] [Download]

  @inproceedings{TUW-282543,
  author = {Galffy, Andras and Car, Florian and Schitter, Georg},
  title = {Calibration and flight test of a 3D printed 5-hole probe for high-dynamic wind measurements for UAV},
  booktitle = {Proceedings of the International Workshop on Research, Education and Development on Unmanned Aerial Systems},
  year = {2019},
  numpages = {10},
  doi = {10.1109/REDUAS47371.2019.8999671},
  note = {Vortrag: International Workshop on Research, Education and Development on Unmanned Aerial Systems, Cranfield, United Kingdom; 2019-11-25 -- 2019-11-27}
  }

Projektpartner

Turbulence Solutions GmbH
T.I.P.S. Messtechnik GmbH
Actaron GmbH

Presse-Artikel

https://noe.orf.at/

https://www.sn.at/

https://diepresse.com/

https://www.krone.at/

Projektfinanzierung

gefördert im Programm Take Off vom Bundesministerium für Verkehr, Innovation und Technologie (bmvit)

  12.12.2018
Klimafloor

Project focus

• Development of an automated robot for the leveling of pour-in insulation
• Evaluation of different control strategies
• Vision-based path planning for obstacle avoidance and optimal distribution of the material

Description

The project deals with the total installation and processing of floor structures including underfloor heating of our industrial partner mixit Dämmstoffe GmbH. In the field of house constructions, the leveling of screed or pour-in insulation is considered an exhausting and harmful task for the construction workers. In order to overcome these issues, our focus in the project lies on the construction of an automated leveling robot in order to increase the distribution quality and achieve a shorter processing time. The robot system consists of several modular components, which allows fast and easy transportation and assembly. To ensure that the working tool stays level, a rotational laser is set up as guidance. In order to avoid contact with obstacles, e.g. walls, distance sensors and a 3D camera are used.

Automation and control of the leveling platform

As a first prototype, an existing platform was used as a starting point. This platform has a SCARA-like structure with a two-linked arm mounted on a foldable tripod and uses a projected laser line to automatically adjust the tool height, while the rest of the system is operated manually. As the base has to be leveled during each new set-up, automation of this process saves a considerable amount of time. In order to facilitate this, two servomotors were mounted on the height-setting screws on the legs and a tilt sensor was added to provide the measurements needed for feedback control. The automatic leveling also allows us to accurately estimate the leg positions without direct measurement, which is later useful during the path planning phase.

For the movement of the arm itself, larger synchronous servomotors were added to each of the three joints in a belt drive configuration. Through inverse kinematics and dynamics, these actuators allow precise control over the end-effector position. Motor torque is also measured and will enable us to use more advanced control strategies, such as impedance control, avoiding potentially harmful hard contact with obstacles.

A novel laser line detector is developed to provide the needed accuracy. With the aim of better suit the intended task, new designs for the robot tool are developed and tested in a construction site environment.

Vision-based obstacle detection and path planning

For the detection of the walls in the 3D point cloud, the Sequential RANSAC (Random Sample Consensus) algorithm is used. In future evaluations, also algorithms such as MultiRANSAC or Residual Histogram Analysis can be tested.

The first step in the vision-based path planning is to obtain the knowledge of the to be processed plane. This is done by detecting the laser line of the rotational laser. With the camera mounted on top of the robot, the plane can be calculated. Subsequently, areas with too much or too less material can be perceived.

Related publications

• M. Bibl, R. Stein, E. Döberl, and G. Schitter, Rotierender optischer Positions- und Winkelsensor, E&I Elektrotechnik und Informationstechnik, vol. 135, iss. 6, p. 396–400, 2018.
  [BibTex]

  @Article{TUW-272096,
  author = {Bibl, Matthias and Stein, Robert and D{\"o}berl, Egon and Schitter, Georg},
  title = {Rotierender optischer Positions- und Winkelsensor},
  journal = {E{\&}I Elektrotechnik und Informationstechnik},
  year = {2018},
  volume = {135},
  number = {6},
  pages = {396--400},
  keywords = {Positions- und Winkelmessung, Rotierender optischer Sensor, Optische Messtechnik},
  doi = {10.1007/s00502-018-0642-3}
  }

• M. Hurban, M. Melik-Merkumians, M. Steinegger, M. Bibl, P. Gsellmann, and G. Schitter, Automated Tripod Leveling and Parameter Estimation for a Granular-fill Insulation Distributing Robot, in Proceedings of the Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019), 2019.
  [BibTex] [Download]

  @InProceedings{TUW-282489,
  author = {Hurban, Milan and Melik-Merkumians, Martin and Steinegger, Michael and Bibl, Matthias and Gsellmann, Peter and Schitter, Georg},
  title = {Automated Tripod Leveling and Parameter Estimation for a Granular-fill Insulation Distributing Robot},
  booktitle = {Proceedings of the Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019)},
  year = {2019},
  volume = {52/15},
  note = {Vortrag: Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019), Wien; 2019-09-04 -- 2019-09-06},
  doi = {10.1016/j.ifacol.2019.11.678},
  journal = {IFAC-PapersOnLine/Elsevier},
  keywords = {Robotic manipulators, Linearization, Kalman Filters, Parameter estimation, LQG control method},
  numpages = {6},
  }

Project partners

• Mixit Dämmstoffe GmbH

Funding

• FFG – Die Österreichische Forschungsförderungsgesellschaft
• Mixit Dämmstoffe GmbH

  05.11.2018
RoboCoop

Robotics Education driven by Interregional  Cooperation

In Schulen und Universitäten gibt es derzeit einen Mangel an Interesse an den MINT‐Fächern (Mathematik, Informatik, Naturwissenschaft und Technik) und an hierfür gut ausgebildeten Lehrkräften in Österreich und der Slowakei. Besonders Frauen sind in den MINT‐Bereichen deutlich unterrepräsentiert. Dies führt zu Engpässen auf dem Arbeitsmarkt, obwohl in der gesamten Region eine steigende Nachfrage nach MINT‐Personal besteht. Robotik in der Bildung hat sich als wertvolles Werkzeug für praktisches Lernen erwiesen, nicht nur für die Robotik selbst, sondern allgemein für MINT‐Themen. RoboCoop ist ein einzigartiges Projekt mit dem Ziel das multidisziplinäre Potenzial der Robotik zu nutzen und grenzüberschreitende Bildungsaktivitäten zu etablieren, um das Interesse an den MINT‐Themen zu wecken.

In RoboCoop werden mehr als 4000 SchülerInnen, Studierende und innovative MINT PädagogInnen auf interregionaler Ebene ermutigt und engagiert, um als positives Beispiel für den breiteren Einsatz auf nationaler Ebene in den beiden Ländern zu dienen. Dazu werden am ACIN Workshops, in denen SchülerInnen die Welt der Roboter kennenlernen und deren Kreativität und Gruppenarbeit gefördert wird, abgehalten. Das didaktische Konzept wechselt zwischen instruktiven und konstruktiven Elementen. Darüber hinaus soll eine umfassende quantitative und qualitative Evaluierung aller Projektaktivitäten zu politischen Empfehlungen führen, um eine systematische und langfristige Umsetzung der Projektideen zu gewährleisten und somit zu einer baldigen Einführung von Robotikthemen auf der Sekundarstufe führen.

 

Partners:

TU Wien – Fakultät für Elektrotechnik und Informationstechnik

ACIN Institut für Automatisierungs- und Regelungstechnik

PRIA – Practical Robotics Institute Austria

SSR Wien – Stadtschulrat Wien

SUK – Slovak University of Technology in Bratislava

CVTI SR – Slovak Centre of Scientific and Technical Information

FUNDING:

Dieses Projekt wird im Rahmen des Kooperationsprogrammes Interreg V-A SK-AT unter der Projektnummer V212 finanziert

 

  24.11.2017
iBridge

Beim Projekt iBridge handelt es sich um ein generationsübergreifendes Projekt, dass die Steigerung des Interesses von Kindern und Jugendlichen an Forschung in sozial- und kulturübergreifenden Szenarien, an Technologie und Innovation sowie einer Vertiefung des Bezugs zu Naturwissenschaft und Technik durch das Thema Robotik in der Altenpflege zum Ziel hat. Um das Interesse der Kinder und Jugendlichen am Thema Robotik zu wecken, kommt das innovative Konzept des „sensitiven Kuscheltieres“ zum Einsatz, von dem dann über die Programmierung von Servicerobotern auf Robotik in der Altenpflege. Auf der anderen Seite des Altersspekturms bemühen sich HTL-SchülerInnen durch PC/Internetkurse in Pensionsitenklubs der Stadt Wien der älteren Generation im Zugang zu modernen Technologien zu unterstützen und achten dabei auf die Bedürfnisse dieser Generation.

  18.10.2017
High-precision electrical AFM modes for biological applications

Electrical modes of Atomic Force Microscopy (AFM) allow the high-resolution mapping of surface charges on a sample with nanometer precision. A particular measurement challenge is to perform such modes on biological samples (tissue extracts, biomolecules, biomembranes, etc). To this end, the project aims to investigate different preparation and measurement approaches and a specific goal is to determine alterations of surface charge of biological fibers caused by the reaction with sugar, which has important implications in medicine and cell biology.

Project focus

• Determine the influence of humidity on ionised, chemical surface groups
• Investigate the charge of glycated protein fibrils

Project partners/collaborators

• Institute of Lightweight Design and Structural Biomechanics, TU Wien (Prof. P. Thurner)
• Department of Chemistry, University of Cambridge, UK (Prof. M. Duer)

Publications

• Kohl, D., P. Mesquida and G. Schitter (2017). „Quantitative AC – Kelvin Probe Force Microscopy.“ Microelectronic Engineering 176: 28-32.
• P.Mesquida, D.Kohl, O.G.Andriotis, P.J.Thurner, M.J.Duer, S.B.Bansode, G.Schitter, Kelvin-probe Force Microscopy to map glycation of proteins, AFM Biomed Conference, Krakow 2017.

  07.09.2017
High resolution long range Lidar for autonomous driving (LiDcAR)

Project focus

• Evaluation and control of scanning systems for Lidar applications
• Precision metrology for MEMS scanning mirrors
• Modeling and identification of Complex dynamics of MEMS scanning mirror
• Advanced sensing and control for MEMS scanning mirror
• Performance assessments of the MEMS scanning systems for automotive lidar

Description

Lidar is an acronym for light detection and ranging, in analogy to radar. Lidar has received much attention in the automotive industry as a key component for high level automated driving systems. Compared to other sensing techniques such as stereo cameras and radar, lidar can provide high resolution and highly accurate 3D measurements of the surroundings and robust detection in various weather conditions. The lidar sensors are expected to ensure the safety in automated driving applications such as collision detection, blind spot monitoring, object and pedestrian recognition, and terrain mapping. Currently Google, BMW, Ford, Volvo and other autonomous car developers include lidar sensors in their systems for safe driving.

The main challenges of this project are in the development and evaluation of the scanning system in the lidar sensor. Currently a polygon scanner, MEMS mirror and optical phase arrays are studied for the potential scanning system. The scanning system for the lidar for autonomous driving requires extreme robustness in harsh environmental conditions, i.e. large temperature range, humidity, dust, shock, and vibration. The scanning system in lidar should provide seamless operation to ensure the safety of the drivers and pedestrians. In addition, the performance of the lidar sensor is defined and measured precisely to ensure the safety requirements with sufficient accuracy.

This project aimed to develop precise and robust scanning systems for lidars. The research includes investigation of the various scanning techniques as well as the methodology to evaluate the performance of the lidar and its scanning system. The developed lidar and evaluation platform was mounted on a vehicle and tested in the field.

Precision metrology of MEMS scanning mirrors

For accurate evaluation of MEMS scanning mirrors, systematic errors of the measurement setup have to be identified and avoided. Hence, a self-calibrated test bench is developed and analyzed regarding its uncertainties of MEMS mirror angle detection. The basic principle is that a laser beam gets deflected by the MEMS mirror and is detected by a position sensitive detector (PSD), where the mirror angle can be recalculated. As alignment uncertainties such as an inaccurate placement of the MEMS mirror in its package cause estimation errors, a semi-automated calibration procedure is developed based on a CCD camera and a motorized stage. The achieved accuracy error of 0.025° at 15° mechanical angle suffices the requirements for automotive Lidar. As a crucial component of the test bench, the PSDs are analyzed regarding the achievable bandwidth while also temperature drifts as well as their compensation schemes are investigated.

Accurate modeling of the MEMS scanning mirror

Accurate modelling and identification of resonant MEMS mirrors dynamics is crucial for control design and allows to identify weaknesses and strengths of the individual MEMS mirror designs. In the presence of nonlinearities, conventional linear system theory fails to predict the behavior of the system as it gets state dependent. In particular, MEMS mirrors exhibit several nonlinearities, such as amplitude dependent damping, angle dependent stiffness as well as actuation forces, which depend on the angular comb-drive capacitance derivative and the driving voltage squared. Hence, an identification method for a general single degree of freedom model was developed to estimate the system parameters solely by measurement data with a minimum on prior assumptions. For advanced control design, a linearized model based on period-to-period energy conservation was developed, which represents the local MEMS mirror dynamics of phase, frequency and amplitude at a nominal operation point. As an extension, slow flow analysis was applied to the identified nonlinear model, which allows a fast calculation of the global and local behavior of the MEMS mirror.

Advanced sensing and control for MEMS mirrors

A precise sensing of the MEMS mirror movement is crucial for robust feedback control. As the size of the MEMS mirror is in the range of view millimeters, dedicated sensors can hardly be applied without complicating the design or increasing production cost. Hence, self-sensing approaches are developed, where the same comb-drives serve as actuators and sensors. The comb-drive capacitance of resonant MEMS mirrors usually has a triangular shape with its maximum at zero angle and deceases in both angular directions in a deterministic manner. Therefore, the measurement of the capacitance directly reveals the mirror angle. For square wave excitation of the MEMS mirror, the charge on the comb-drive capacitance is direct proportional to the capacitance and therefore serves as an angle sensor. However, the measurement time is limited to the time where the driving voltage is on, which lead to the development of a switched input observer to estimate the MEMS mirror angle also between the measurement windows, i.e. where the driving voltage is off.

A precise zero crossing measurement is obtained by the displacement current flowing through the comb-drives during a constant driving voltage as depicted in Fig. 4. The current signal shows a sharp zero crossing when the mirror passes zero angle, which can be precisely detected by a simple comparator.

For performance evaluation of the phase detection, the Digital Asynchronous PLL (DAsPLL) was developed, which operates the MEMS mirror with immediate phase error compensation and showed a center pixel uncertainty error of less than 0.3 mdeg at 58° field of view. Key feature of the DAsPLL is the asynchronous switching off of the driving voltage by bypassing the zero crossing comparator detection signal without clock speed limitations of the FPGA.

Also a conventional PLL structure was analyzed, where the driving frequency is adjusted according to the measured phase errors with an appropriate control law. The derived linear models of the MEMS mirror allowed a simple and robust control design and revealed that due to the nonlinear stiffness of the MEMS mirror, a proportional gain is crucial as only integral control leads to large settling times of the system or even instability.

Applications

• Lidar for autonomous driving
• Precision measurement system

Related Publications and Patents

Journal articles

• D. Brunner, H. W. Yoo, and G. Schitter, Linear Modeling and Control of Comb-Actuated Resonant MEMS Mirror with Nonlinear Dynamics, IEEE Transactions on Industrial Electronics, vol. 68, iss. 4, p. 3315–3323, 2021.
  [BibTex] [Download]

  @article{TUW-288425,
  author = {Brunner, David and Yoo, Han Woong and Schitter, Georg},
  title = {Linear Modeling and Control of Comb-Actuated Resonant MEMS Mirror with Nonlinear Dynamics},
  journal = {IEEE Transactions on Industrial Electronics},
  year = {2021},
  volume = {68},
  number = {4},
  pages = {3315--3323},
  doi = {10.1109/TIE.2020.2982124},
  keywords = {Energy conservation, laser radar, linearization techniques, microelectromechanical system (MEMS), micromirrors, nonlinear systems, parameter estimation, phase locked loops (PLL), system identification.}
  }

• H. W. Yoo, S. Albert, and G. Schitter, Accurate Analytic Model of a Parametrically Driven Resonant MEMS Mirror with a Fourier Series Based Torque Approximation, Journal of Microelectromechanical Systems, vol. 29, iss. 6, p. 1431–1442, 2020.
  [BibTex] [Download]

  @article{TUW-290470,
  author = {Yoo, Han Woong and Albert, Stephan and Schitter, Georg},
  title = {Accurate Analytic Model of a Parametrically Driven Resonant MEMS Mirror with a Fourier Series Based Torque Approximation},
  journal = {Journal of Microelectromechanical Systems},
  year = {2020},
  volume = {29},
  number = {6},
  pages = {1431--1442},
  doi = {10.1109/JMEMS.2020.3024752},
  keywords = {Mirrors , Micromechanical devices , Torque , Analytical models , Mathematical model , Capacitance , Fourier series}
  }

• D. Brunner, H. W. Yoo, and G. Schitter, Precise phase control of resonant MOEMS mirrors by comb-drive current feedback, Mechatronics, vol. 71, p. 102420, 2020.
  [BibTex] [Download]

  @article{TUW-290167,
  author = {Brunner, David and Yoo, Han Woong and Schitter, Georg},
  title = {Precise phase control of resonant MOEMS mirrors by comb-drive current feedback},
  journal = {Mechatronics},
  year = {2020},
  volume = {71},
  pages = {102420},
  doi = {10.1016/j.mechatronics.2020.102420},
  keywords = {Comb-drive, Digital asynchronous phase locked loop (DAsPLL), Micro-opto-electro-mechanical system (MOEMS), Nonlinear systems, Precision control, Resonant scanning mirror}
  }

• H. W. Yoo, N. Druml, D. Brunner, C. Schwärzl, T. Thurner, M. Hennecke, and G. Schitter, MEMS-based lidar for autonomous driving, E&I Elektrotechnik und Informationstechnik, vol. 135, iss. 6, p. 408–415, 2018.
  [BibTex] [Download]

  @Article{TUW-273071,
  author = {Yoo, Han Woong and Druml, N. and Brunner, David and Schw{\"a}rzl, Christian and Thurner, Thomas and Hennecke, Markus and Schitter, Georg},
  title = {MEMS-based lidar for autonomous driving},
  journal = {E{\&}I Elektrotechnik und Informationstechnik},
  year = {2018},
  volume = {135},
  number = {6},
  pages = {408--415},
  keywords = {lidar; MEMS scanning mirror; autonomous driving; metrology platform},
  doi = {10.1007/s00502-018-0635-2},
  }

Conference papers

• R. Schroedter, H. W. Yoo, D. Brunner, and G. Schitter, Capacitive Charge-based Self-Sensing for Resonant Electrostatic MEMS mirrors, in Proceedings of the 21st IFAC World Congress, 2020.
  [BibTex] [Download]

  @inproceedings{TUW-292461,
  author = {Schroedter, Richard and Yoo, Han Woong and Brunner, David and Schitter, Georg},
  title = {Capacitive Charge-based Self-Sensing for Resonant Electrostatic MEMS mirrors},
  booktitle = {Proceedings of the 21st IFAC World Congress},
  year = {2020},
  numpages = {6},
  keywords = {Resonant MEMS mirror, electrostatic comb drive, capacitive charge sensing, nonlinear observer with switched input},
  note = {Vortrag: 21st IFAC World Congress, Berlin; 2020-07-12 -- 2020-07-17}
  }

• H. W. Yoo and G. Schitter, Complex Valued State Space Model for Weakly Nonlinear Duffing Oscillator with Noncollocated External Disturbance, in Proceedings of the 21st IFAC World Congress, 2020.
  [BibTex] [Download]

  @inproceedings{TUW-290466,
  author = {Yoo, Han Woong and Schitter, Georg},
  title = {Complex Valued State Space Model for Weakly Nonlinear Duffing Oscillator with Noncollocated External Disturbance},
  booktitle = {Proceedings of the 21st IFAC World Congress},
  year = {2020},
  numpages = {7},
  keywords = {Duffing oscillator, complex valued model, perturbation theory, disturbance model, noncollocated disturbance, MEMS mirror, automotive lidar},
  note = {Vortrag: 21st IFAC World Congress, Berlin; 2020-07-12 -- 2020-07-17}
  }

• D. Brunner, H. W. Yoo, and G. Schitter, Digital Asynchronous Phase Locked Loop for Precision Control of MOEMS Scanning Mirror, in Proceedings of the Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019), 2019.
  [BibTex] [Download]

  @InProceedings{TUW-282514,
  author = {Brunner, David and Yoo, Han Woong and Schitter, Georg},
  title = {Digital Asynchronous Phase Locked Loop for Precision Control of MOEMS Scanning Mirror},
  booktitle = {Proceedings of the Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019)},
  year = {2019},
  volume = {52/15},
  note = {Vortrag: Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019), Wien; 2019-09-04 -- 2019-09-06},
  doi = {10.1016/j.ifacol.2019.11.647},
  journal = {IFAC-PapersOnLine/Elsevier},
  keywords = {Digital asynchronous phase locked loop (DAsPLL), Micro-Opto-Electro-Mechanical System (MOEMS), Resonant scanning mirror, Comb-drive, Nonlinear systems.},
  numpages = {6},
  }

• H. W. Yoo, D. Brunner, T. Thurner, and G. Schitter, MEMS Test Bench and its Uncertainty Analysis for Evaluation of MEMS Mirrors, in Proceedings of the Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019), 2019.
  [BibTex] [Download]

  @InProceedings{TUW-283447,
  author = {Yoo, Han Woong and Brunner, David and Thurner, Thomas and Schitter, Georg},
  title = {MEMS Test Bench and its Uncertainty Analysis for Evaluation of MEMS Mirrors},
  booktitle = {Proceedings of the Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019)},
  year = {2019},
  volume = {52/15},
  note = {Vortrag: Joint Conference 8th IFAC Symposium on Mechatronic Systems (MECHATRONICS 2019), and 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS 2019), Wien; 2019-09-04 -- 2019-09-06},
  doi = {10.1016/j.ifacol.2019.11.648},
  journal = {IFAC-PapersOnLine/Elsevier},
  keywords = {Metrology, Uncertainty analysis, Characterization, Microelectromechanical systems (MEMS), MEMS mirror},
  numpages = {6},
  }

• D. Brunner, H. W. Yoo, T. Thurner, and G. Schitter, Data based Modelling and Identification of Nonlinear SDOF MOEMS Mirror, in MOEMS and Miniaturized Systems XVIII, 2019.
  [BibTex] [Download]

  @InProceedings{TUW-282507,
  author = {Brunner, David and Yoo, Han Woong and Thurner, Thomas and Schitter, Georg},
  title = {Data based Modelling and Identification of Nonlinear SDOF MOEMS Mirror},
  booktitle = {MOEMS and Miniaturized Systems XVIII},
  year = {2019},
  volume = {10931},
  note = {Vortrag: SPIE Photonics West 2019, San Francisco, California, USA; 2019-02-02 -- 2019-02-07},
  doi = {10.1117/12.2508429},
  journal = {SPIE},
  keywords = {Micro-Opto-Electro-Mechanical System (MOEMS), Resonant scanning mirror, Data based identification, Generalized nonlinear SDOF model, Actuated decay, Comb-drive torque},
  numpages = {11},
  }

• H. W. Yoo, D. Brunner, T. Thurner, and G. Schitter, Compensation for Temperature Dependency of 1D Position Sensitive Detector, in Advances in Display Technologies IX, 10942, 2019.
  [BibTex] [Download]

  @InProceedings{TUW-283433,
  author = {Yoo, Han Woong and Brunner, David and Thurner, Thomas and Schitter, Georg},
  title = {Compensation for Temperature Dependency of 1D Position Sensitive Detector},
  booktitle = {Advances in Display Technologies IX},
  year = {2019},
  address = {10942},
  publisher = {SPIE},
  note = {Vortrag: SPIE Photonics West 2019, San Francisco, California, USA; 2019-02-02 -- 2019-02-07},
  doi = {10.1117/12.2508403},
  keywords = {Position sensitive detector (PSD), High temperature operation, Leakage current, Point drift measurement, Reliability test}
  }

Patents

• H. W. Yoo, M. E. Hennecke, G. Schitter, and T. Thurner, Real time gating and signal routing in laser and detector arrays for lidar applications, U.S. Patent, iss. US 2020/0200877 A1, 2020.
  [BibTex]

  @patent{TUW-292557,
  author = {Yoo, Han Woong and Hennecke, Markus Edward and Schitter, Georg and Thurner, Thomas},
  title = {Real time gating and signal routing in laser and detector arrays for lidar applications},
  journal = {U.S. Patent},
  number = {US 2020/0200877 A1},
  year = {2020},
  note = {eingereicht: 2019-02-01, erteilt: 2020-06-25}
  }

• H. W. Yoo, M. E. Hennecke, G. Schitter, and T. Thurner, Echtzeit-gating und Signal Wegleitung in Laser- und Detektorarrays für LiDAR-Anwendungen, Deutsches Patent- und Markenamt, iss. DE 10 2019 220 289 A1, 2020.
  [BibTex]

  @patent{TUW-292552,
  author = {Yoo, Han Woong and Hennecke, Markus Edward and Schitter, Georg and Thurner, Thomas},
  title = {Echtzeit-gating und Signal Wegleitung in Laser- und Detektorarrays f{\"u}r LiDAR-Anwendungen},
  journal = {Deutsches Patent- und Markenamt},
  number = {DE 10 2019 220 289 A1},
  year = {2020},
  note = {eingereicht: 2019-12-19, erteilt: 2020-06-25}
  }

• T. Thurner, D. Brunner, M. E. Hennecke, G. Schitter, and H. W. Yoo, LiDAR-Sensoren und Verfahren für LiDAR-Sensoren, Deutsches Patent- und Markenamt, iss. DE 10 2018 128 164 A1, 2020.
  [BibTex]

  @patent{TUW-292555,
  author = {Thurner, Thomas and Brunner, David and Hennecke, Markus Edward and Schitter, Georg and Yoo, Han Woong},
  title = {LiDAR-Sensoren und Verfahren f{\"u}r LiDAR-Sensoren},
  journal = {Deutsches Patent- und Markenamt},
  number = {DE 10 2018 128 164 A1},
  year = {2020},
  howpublished = {Patent},
  note = {eingereicht: 2018-11-12, erteilt: 2020-05-14}
  }

• T. Thurner, D. Brunner, M. E. Hennecke, G. Schitter, and H. W. Yoo, Lidar sensors and methods for lidar sensors, U.S. Patent, iss. US 2020/0150246 A1, 2020.
  [BibTex]

  @patent{TUW-292556,
  author = {Thurner, Thomas and Brunner, David and Hennecke, Markus Edward and Schitter, Georg and Yoo, Han Woong},
  title = {Lidar sensors and methods for lidar sensors},
  journal = {U.S. Patent},
  number = {US 2020/0150246 A1},
  year = {2020},
  howpublished = {Patent},
  note = {eingereicht: 2019-11-11, erteilt: 2020-05-14}
  }

Press Release

• https://futurezone.at/science/wie-fahrerlose-autos-dank-laser-besser-sehen/400568591
• https://infothek.bmvit.gv.at/selbstfahrende-autos-erobern-die-steiermark/

Project partners

• Infineon Technologies
• Virtual Vehicle

Funding

• FFG Mobilität der Zukunft
• Infineon Technologies

  28.08.2017
Modellierung und optimale Regelung von elektrischen Motoren mit redundanten Wicklungssystemen

Projektschwerpunkte

• Modellierung von PMSM mit redundanten Statorwicklungen
• Detektion von Fehlern der PMSM
• Optimale fehlertolerante Regelungsstrategien für PMSM mit redundanten Statorwicklungen

Beschreibung

Permanentmagnet-Synchronmaschinen (PMSM) werden aufgrund ihrer hohen Leistungsdichte in vielen industriellen und automotiven Anwendungen eingesetzt. In einigen dieser Anwendung (z.B. elektrische Servolenksysteme) kann ein Fehler des Motors (z.B. Kurzschluss von Statorwicklungen oder Kabelbruch), des Inverters oder der Sensorik (Positions- und Stromsensorik) zu einem unerwünschten und potenziell gefährlichen Verhalten führen. Um einen sicheren Betrieb der PMSM auch im Fehlerfall zu gewährleisten, wurden Konstruktionen mit redundanten Statorwicklungen und Inverterzweigen in der Literatur vorgeschlagen, siehe, z.B., Fig. 1. Die große Anzahl von möglichen Motorkonstruktionen beruht immer auf der Grundidee, mehr als drei Statorwicklungen zu verwenden die durch unabhängige Inverterzweige angesteuert werden. Dies ermöglicht den Betrieb der PMSM im Fall eines einzelnen Fehlers, wenngleich eventuell mit verringerter Leistung. Verwendet man zusätzlich eine Positionsschätzung für die PMSM, so kann die PMSM auch im Fall eines Fehlers des Positionssensors betrieben werden.

Die Mehrzahl der bekannten fehlertoleranten Regelungsstrategien und sensorlosen Positionsschätzmethoden basieren auf einem magnetisch linearen Grundwellenmodell der PMSM in dq-Darstellung. In dieser Forschungskooperation mit der Firma Robert Bosch GmbH werden Strategien zur Fehlerdetektion, zum fehlertoleranten Betrieb sowie für die optimale (sensorlose) Regelung von Permanentmagnet-Synchronmotoren entwickelt, die eine systematische Berücksichtigung der magnetischen Sättigung sowie von beliebigen Feldverläufen erlauben. Die Basis für diese Methoden bildet eine Beschreibung der PMSM mit Hilfe von Reluktanznetzwerken, welche zu Modellen mit geringer Komplexität führt, die besonders für die Systemanalyse und den Reglerentwurf geeignet sind. Die betrachteten Anwendungen der resultierenden Schätz- und Regelungsstrategien liegen in automotiven Anwendungen, wie z.B. elektrische Servolenksysteme oder elektrischen Antriebsstränge.

Projektpartner

• Robert Bosch GmbH

  25.08.2017
Modellierung und Regelung von Spritzgießmaschinen

Projektschwerpunkte

• Modellbasierter Entwurf von optimalen Regelungsstrategien für die Einspritz- und Nachdruckphase
• Modellbasierte Regelung der Temperaturverteilung in der Spritzgießmaschine
• Anwendung für Spritzgießmaschinen mit hydraulischem Direktantrieb

Beschreibung

Spritzgießen ist das am weitesten verbreitete Produktionsverfahren zum Erzeugen von Bauteilen aus Kunststoff. Dabei wird Kunststoffgranulat in einer Spritzgießmaschine durch Erwärmung und Deformation mit Hilfe einer Förderschnecke verflüssigt. Der flüssige Kunststoff sammelt sich im Schneckenvorraum. Wird die Schnecke nach vorne bewegt, so fließt der flüssige Kunststoff aus dem Schneckenvorraum und die Form wird gefüllt. Wenn der Kunststoff in der Form hinreichend abgekühlt ist, dann kann das fertige Kunststoffteil entnommen werden und der Prozess beginnt von vorne.

Eine wesentliche Grundlage zur Gewährleistung einer gleichmäßig hohen Produktqualität ist eine hohe Stabilität des Einspritzprozesses von einem Einspritzvorgang zum nächsten. Die wesentlichen Prozessgrößen sind hierbei die Temperaturen, die Einspritzgeschwindigkeiten sowie die Einspritzdrücke. Um diese Prozessgrößen möglichst genau und reproduzierbar vorzugeben, sind geeignete Regelungsstrategien notwendig. In dieser Forschungskooperation mit der Firma Engel werden optimale Regelungsstrategien für die Einspritzregelung (Geschwindigkeit, Druck) sowie die Temperaturregelung für Spritzgießmaschinen entwickelt. Ein Schwerpunkt liegt dabei auf hydraulisch aktuierten Spritzgießmaschinen mit Direktantrieb (Servopumpe), die sich durch eine verbesserte energetische Effizienz im Vergleich zu hydraulischen Spritzgießmaschinen mit Ventilsteuerung auszeichnen. Die Regelung für diese Bauform von Spritzgießmaschinen wird jedoch dadurch erschwert, dass die Dynamik der Aktorik wesentlich geringer ist.

Projektpartner

• Engel

  24.08.2017
Modellierung und optimale Regelung von Permanentmagnet-Synchronmotoren

Projektschwerpunkte

• Reluktanzmodellierung von Permanentmagnet-Synchronmotoren (PMSM)
• Systematische Berücksichtigung von magnetischer Sättigung und nicht-sinusförmiger Feldverläufe
• Optimale Regelung des Moments
• Sensorlose Verfahren zur Positionsbestimmung von PMSM

Beschreibung

Permanentmagnet-Synchronmotoren (PMSM) werden in vielen industriellen Anwendungen, wie z.B. der Robotik, aufgrund ihrer hohen Momentendichte und hohen energetischen Effizienz eingesetzt. Für die Regelung von PMSM ist die feldorientierte Regelung industrieller Standard. Diese Regelungsstrategie beruht auf einer Transformation der winkelabhängigen Größen des PMSM auf ein mit dem Rotor fest verbundenes orthogonales dq0-Koordinatensystem. Wesentliche Annahme ist dabei die magnetische Linearität des Motors sowie eine Grundwellenapproximation der Feldgrößen des Motors.

Moderne Motorkonstruktionen verwenden meist Einzelzahnspulen und einen nicht homogenen Luftspalt, wodurch die Annahme sinusförmigen Verläufe mehr oder weniger verletzt ist. Weiterhin werden PMSM häufig bis in den Bereich maßgeblicher Sättigung betrieben. Damit sind die Annahmen der klassischen feldorientierten Regelung in vielen Anwendungen mehr oder weniger verletzt.

In dieser Forschungskooperation mit der Firma Bernecker und Rainer Industrieelektronik GmbH (B&R) werden Methoden zur systematischen mathematischen Beschreibung von PMSM mit ausgeprägter Sättigung sowie nicht sinusförmigen Feldgrößen untersucht. Dazu wird die Methode der Reluktanzmodellierung angewandt, bei der der magnetische Kreis des PMSM mit einer Verschaltung von magnetischen Widerständen (Reluktanzen) und magnetischen Spannungsquellen (Spulen, Permanentmagnete) approximiert wird, siehe Abb. 1.

Die Anwendung der aus der elektrischen Schaltungstechnik bekannten Netzwerkstheorie erlaubt eine systematische Bestimmung der Modellgleichungen für beliebige Motorkonstruktionen mit relativ komplexen Reluktanznetzwerken, siehe z.B. Fig. 2. Weiterhin können damit systematisch magnetische Sättigung und nicht sinusförmige Feldgrößen berücksichtigt werden.

Da sich diese Modelle auch durch eine relativ geringe Modellkomplexität auszeichnen, sind diese Modelle eine gute Basis für modellbasierte Regelungsstrategien. Im Rahmen dieses Forschungsprojektes werden optimierungsbasierte Regelungsstrategien entwickelt, die z.B. eine indirekte Momentenregelung mit gleichzeitiger Minimierung der Verluste des PMSM erlauben. Damit lässt sich eine wesentliche Verbesserung der Momentenregelgüte im Vergleich zu einer klassischen feldorientierten Regelungsstrategie erreichen, siehe z.B. Abb. 3.

Der modellbasierte Ansatz erlaubt die einfache Übertragung auf andere Baugrößen und Bauformen von elektrischen Motoren. Insbesondere lassen sich die Ergebnisse auch auf Linearmotoren übertragen. Weiterhin bilden die mathematischen Modelle eine gute Basis auch für die sensorlose Positionsbestimmung von PMSM.

Ausgewählte Publikationen

• D. Faustner, W. Kemmetmüller, and A. Kugi, Flatness-Based Torque Control of Saturated Surface-Mounted Permanent Magnet Synchronous Machines, IEEE Transactions on Control Systems Technology, vol. 24, iss. 4, p. 1201–1213, 2016.
  [BibTex] [Download]

  @Article{Faustner16,
  Title = {Flatness-Based Torque Control of Saturated Surface-Mounted Permanent Magnet Synchronous Machines},
  Author = {Faustner, D. and Kemmetm{\"u}ller, W. and Kugi, A.},
  Journal = {IEEE Transactions on Control Systems Technology},
  Pages = {1201--1213},
  Volume = {24},
  Year = {2016},
  Number = {4},
  Doi = {10.1109/TCST.2015.2501345},
  ISSN = {1063-6536},
  }

• D. Faustner, W. Kemmetmüller, and A. Kugi, Experimental Parameterization of a Design Model for Flatness-Based Torque Control of a Saturated Surface-Mounted PMSM, in Proceedings of the 7th IFAC Symposium on Mechatronic Systems & 15th Mechatronics Forum International Conference, Loughborough, UK, 2016, p. 575–582.
  [BibTex]

  @InProceedings{Faustner16a,
  author = {Faustner, D. and Kemmetm\"uller, W. and Kugi, A.},
  title = {Experimental Parameterization of a Design Model for Flatness-Based Torque Control of a Saturated Surface-Mounted PMSM},
  booktitle = {Proceedings of the 7th IFAC Symposium on Mechatronic Systems \& 15th Mechatronics Forum International Conference},
  year = {2016},
  volume = {49},
  number = {21},
  month = {9},
  pages = {575--582},
  doi = {10.1016/j.ifacol.2016.10.663},
  address = {Loughborough, UK},
  issn = {2405-8963},
  }

• D. Faustner, W. Kemmetmüller, and A. Kugi, Magnetic Equivalent Circuit Modeling of a Saturated Surface-Mounted Permanent Magnet Synchronous Machine, in Proceedings of the 8th Vienna International Conference on Mathematical Modelling (MATHMOD), Vienna, Austria, 2015, p. 360–365.
  [BibTex]

  @InProceedings{Faustner15,
  author = {Faustner, D. and Kemmetm\"uller, W. and Kugi, A.},
  title = {Magnetic Equivalent Circuit Modeling of a Saturated Surface-Mounted Permanent Magnet Synchronous Machine},
  booktitle = {Proceedings of the 8th Vienna International Conference on Mathematical Modelling (MATHMOD)},
  year = {2015},
  month = {2},
  pages = {360--365},
  doi = {10.1016/j.ifacol.2015.05.033},
  address = {Vienna, Austria},
  }

• D. Faustner, W. Kemmetmüller, and A. Kugi, Field Weakening in Flatness-Based Torque Control of Saturated Surface-Mounted Permanent Magnet Synchronous Machines, in Proceedings of the 2015 IEEE Conference on Control Applications (CCA), Sydney, Australia, 2015, p. 858–863.
  [BibTex]

  @InProceedings{Faustner15a,
  author = {Faustner, D. and Kemmetm\"uller, W. and Kugi, A.},
  title = {Field Weakening in Flatness-Based Torque Control of Saturated Surface-Mounted Permanent Magnet Synchronous Machines},
  booktitle = {Proceedings of the 2015 IEEE Conference on Control Applications (CCA)},
  year = {2015},
  publisher = {IEEE},
  month = {9},
  pages = {858--863},
  doi = {10.1109/CCA.2015.7320725},
  address = {Sydney, Australia},
  }

• W. Kemmetmüller, D. Faustner, and A. Kugi, Optimale Nichtlineare Regelung von permantenterregten Synchronmaschinen, at – Automatisierungstechnik, vol. 63, iss. 9, p. 739–750, 2015.
  [BibTex] [Download]

  @Article{Kemmetmueller15a,
  Title = {Optimale Nichtlineare Regelung von permantenterregten Synchronmaschinen},
  Author = {Kemmetm\"uller, W. and Faustner, D. and Kugi, A.},
  Journal = {at -- Automatisierungstechnik},
  Pages = {739--750},
  Volume = {63},
  Year = {2015},
  Number = {9},
  Doi = {10.1515/auto-2015-0041},
  }

• W. Kemmetmüller, D. Faustner, and A. Kugi, Optimal torque control of permanent magnet synchronous machines using magnetic equivalent circuits, Mechatronics, vol. 32, p. 22–33, 2015.
  [BibTex] [Download]

  @Article{Kemmetmueller15b,
  Title = {Optimal torque control of permanent magnet synchronous machines using magnetic equivalent circuits},
  Author = {Kemmetm\"uller, W. and Faustner, D. and Kugi, A.},
  Journal = {Mechatronics},
  Pages = {22--33},
  Volume = {32},
  Year = {2015},
  Doi = {10.1016/j.mechatronics.2015.10.007},
  ISSN = {0957-4158},
  }

• W. Kemmetmüller, D. Faustner, and A. Kugi, Modeling of a permanent magnet synchronous machine with internal magnets using magnetic equivalent circuits, IEEE Transactions on Magnetics, vol. 50, iss. 6, 2014.
  [BibTex] [Download]

  @Article{Kemmetmueller14,
  Title = {Modeling of a permanent magnet synchronous machine with internal magnets using magnetic equivalent circuits},
  Author = {Kemmetm{\"u}ller, Wolfgang and Faustner, David and Kugi, Andreas},
  Journal = {IEEE Transactions on Magnetics},
  Volume = {50},
  Year = {2014},
  Number = {6},
  Doi = {10.1109/TMAG.2014.2299238},
  }

Projektpartner

• Bernecker & Rainer Industrieelektronik GmbH