09.10.2019
HEAP

Human-Guided Learning and Benchmarking of Robotic Heap Sorting

In HEAP we focus on advancing the state-of-the-art for sorting a heap of unknown, irregular objects and provide appropriate benchmarks. In our scenarios, we deal with unknown, broken or deformed object instances such as concrete, metal pipes and other plastic/metal parts of possibly complex shape. A major goal of this project is to make challenging manipulation tasks easily accessible and reproducible, and to allow for a comparative evaluation of different approaches using a standardized robotic platform and an open source simulation framework. Our intention in providing such a benchmark framework is to (i) evaluate state-of-the-art grasping and manipulation algorithms in these complex heap sorting setups and (ii) to define new challenges in terms of object recognition and manipulation that need to be solved by the community.

FUNDING:

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

  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.

Landeanflug in atmosphärischer Turbulenz – Visualisierung der lokalen Verteilung von Auftrieb und Luftwiderstands

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.

Disturbance acceleration of an aircraft in atmospheric turbulence without and with turbulence suppression

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}
    }

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.

Automated robot platform for the leveling of pour-in insulation

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.

Point cloud of robot during leveling process

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

Funding

  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.

Figure 1: KFM surface potential map of a collagen fibril on graphite. The bright spots show areas of positive charge.

Project focus

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

Project partners/collaborators

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.

(Left) Line scan lidar based on a 1D resonant MEMS mirror and a detector array. (Right) Example of a 1D resonant MEMS mirror with electrostatic comb-drive actuation.

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.

(Left) MEMS test bench with semi-automated calibration and alignment capabilities. (Right) Uncertainty analysis of MEMS mirror angle detection and component-wise contribution.

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.

(Left) Comparison of measured and simulated frequency response. (Right) Comparison of measured and simulated frequency response of the local dynamics at the nominal operation point.

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.

(Left) Switched input observer scheme for self-sensing mirror trajectory estimation. (Right) Convergence of the switched input observer and comparison with the true angle measurement (PSD). The observer obtains the sense signal only, while the PSD is only for evaluation.

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.

(Left) Example of trajectory, driving signal and current signal. (Right) Scheme of the DAsPLL.

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.

(Left) Conventional PLL structure. (Right) Root locus of closed loop system model and dependency on proportional and integral gain of the PLL controller.

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

Project partners

Funding

  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.

Aufbau von Statorwicklungen mit einem Dreiphasen-Wicklungssystem und zwei Dreiphasen-Wicklungssysteme

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

  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.

Photo einer Spritzgießmaschine

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