39 research outputs found
Dry Clutch Modeling, Estimation, and Control
A Doctor’s degree comprises 240 ECTS credits (4 years of full-time postgraduate studies), of which at least 120 ECTS credits constitute a doctoral dissertation
Entwicklung einer Vorgehensweise zur Bestimmung und Verifikation von Wärmeübergangsparametern aus CFD Simulationen von Trockenkupplungssystemen = Development of an Estimation and Verification Approach for Heat Transfer Parameters of DryClutch Systems Obtained from CFD Simulations
Die Dimensionierung einer Kupplung für manuelle Schaltgetriebe ist stark von den Temperaturen im Friktionskontakt abhängig. Das richtige Verständnis für die Einstufung der Wärmeübertragungsmechanismen und der Randbedingungen ist eine Schlüsselstelle in der Ermittlung der Kupplungsgröße. Diese Arbeit widmet sich der Charakterisierung des Wärmeübergangs von Trockenkupplungssystemen, dem Prozess der Ergebnisvereinfachung und ?validierung, die von einer CFD Simulation generiert wurden
Space Mechanisms Lessons Learned Study. Volume 2: Literature Review
Hundreds of satellites have been launched to date. Some have operated extremely well and others have not. In order to learn from past operating experiences, a study was conducted to determine the conditions under which space mechanisms (mechanically moving components) have previously worked or failed. The study consisted of an extensive literature review that included both government contractor reports and technical journals, communication and visits (when necessary) to the various NASA and DOD centers and their designated contractors (this included contact with project managers of current and prior NASA satellite programs as well as their industry counterparts), requests for unpublished information to NASA and industry, and a mail survey designed to acquire specific mechanism experience. The information obtained has been organized into two volumes. Volume 1 provides a summary of the lesson learned, the results of a needs analysis, responses to the mail survey, a listing of experts, a description of some available facilities, and a compilation of references. Volume 2 contains a compilation of the literature review synopsis
Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015
This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version
Multibody dynamics 2015
This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: Formulations and Numerical Methods, Efficient Methods and Real-Time Applications, Flexible Multibody Dynamics, Contact Dynamics and Constraints, Multiphysics and Coupled Problems, Control and Optimization, Software Development and Computer Technology, Aerospace and Maritime Applications, Biomechanics, Railroad Vehicle Dynamics, Road Vehicle Dynamics, Robotics, Benchmark Problems. The conference is organized by the Department of Mechanical Engineering of the Universitat Politècnica de Catalunya (UPC) in Barcelona. The organizers would like to thank the authors for submitting their contributions, the keynote lecturers for accepting the invitation and for the quality of their talks, the awards and scientific committees for their support to the organization of the conference, and finally the topic organizers for reviewing all extended abstracts and selecting the awards nominees.Postprint (published version
Analyse und Identifikation des quasistationären Verhaltens der Drehmomentübertragung von automatisierten Reibungskupplungen in Kraftfahrzeugen
Die meisten, praxisrelevanten Konzepte zur Regelung von automatisierten Reibungskupplungen
in Kraftfahrzeugen stellen eine Kombination aus Vorsteuerung und Regelung dar. Mit
Hilfe der Vorsteuerung wird der Hauptanteil der erforderlichen Kupplungsstellgröße gebildet.
Die unterlagerte Regelung dient im Wesentlichen dem Ausgleich von Ungenauigkeiten der
Vorsteuerung. Infolgedessen spielt das zur Vorsteuerung verwendete Modell des Kupplungsverhaltens
eine sehr wichtige Rolle und entscheidet maßgeblich über Schaltkomfort und
Verschleißverhalten einer Reibungskupplung während des Fahrbetriebs. Im Bereich automatisierter
Kupplungen werden als Vorsteuerungsmodelle überwiegend Kupplungskennlinien
eingesetzt. Eine Kupplungskennlinie beschreibt dabei den quasistationären Zusammenhang
zwischen der Stellgröße der Kupplung und dem übertragbaren Kupplungsmoment. Abhängig
von verschiedensten Einflussfaktoren unterliegt die Kupplungskennlinie während des Fahrbetriebs
sowohl dauerhaften als auch temporären Änderungen. Um die erforderliche Regelgüte
des Gesamtregelkreises zu gewährleisten, ist es erforderlich, Änderungen des Kupplungsverhaltens
schnell zu erkennen und die Kupplungskennlinie entsprechend anzupassen.
Zur Anpassung der Kupplungskennlinie an die aktuelle Betriebssituation werden in dieser
Arbeit ausgewählte Methoden der Systemidentifikation eingesetzt. Zur Approximation der
Kupplungskennlinie wird ein neues Kennlinienmodell eingesetzt. Dieses Modell zeichnet sich
durch zwei wesentliche Merkmale, seine analytische und parametrische Form sowie die
physikalisch-geometrische Interpretierbarkeit der Modellparameter, aus. Das erste Merkmal
ermöglicht den Einsatz von ableitungsbasierter Least-Squares Methoden der zur Ermittlung
unbekannter Modellparameter. Diese Methoden sind konzipiert zur Verarbeitung von verrauschten
Signalen und bitten eine sehr hohe Robustheit der Kennlinienidentifikation unter
realen Bedingungen. Das zweite Merkmal ermöglicht eine separate Modifikation einzelner
Modellparameter unter Berücksichtigung ihrer Änderungsdynamik bzw. ihrer Zeitvarianz
während des Fahrbetriebs. Die Untersuchungen der Kennlinienidentifikation erfolgen
zunächst in der Simulation. Dadurch können einzelne Effekte der Drehmomentübertragung
ab- bzw. zugeschaltet und deren Auswirkung auf den Identifikationsvorgang gezielt analysiert
werden. Anschließend erfolgen ausführliche Untersuchungen der Kennlinienidentifikation
anhand von realen Fahrzeugmessungen. Die erzielten Ergebnisse belegen zum einen eine
hohe Performance der vorgestellten Methodik zur Identifikation von Kupplungskennlinien.
Zum anderen decken sie Potentiale für weiterführende Arbeiten im Bereich der Identifikation
des Übertragungsverhaltens von Reibungskupplungen auf.Many practice-relevant concepts for controlling automated friction clutches in motor vehicles
are designed as a combination of feed forward and feedback control. The main amount of the
actuating variable required for the clutch engagement is calculated by the feed forward path.
The task of the feedback path is to compensate for the uncertainness of the feed forward path.
Therefore, the model used for the feed forward path is very important for the shift comfort as
well as for the wear of the clutch system during operation. In the field of automated clutches,
the clutch characteristic is typically used as the feed forward model. A clutch characteristic
represents the relationship between the actuating variable and the torque transferred through
the clutch. Dependent on various factors, the clutch characteristic changes both temporarily
and permanently during the operation. To ensure the requirements for the clutch control, it is
necessary to track the relevant changes of the behavior of the clutch system, as well as to
adapt the clutch characteristic accordingly.
In this work, preselected identification methods are used for the adaption of the clutch
characteristic on the actual operating point. Thereby, the approximation of the clutch
characteristic is carried out using an innovative model. This model is characterized by two
essential properties, these are the analytically and parametrically model form, as well as the
physically and geometrically interpretability of the model parameter. The first property allows
using derivative-based identification methods for determination of unknown parameters of the
characteristic model. These methods provide a high robustness of the identification of the
clutch characteristics under realistically operating conditions because they are designed for
processing signals corrupted by noise. The second property of the new characteristic model
allows an identification of the model parameter under consideration their change dynamics
and time variance respectively.
In the first step, the identification of the clutch characteristic was investigated in simulation.
This allows activating or deactivating of diverse effects of the torque transfer through the
clutch, with the goal, to analyze the influence of these effects on the identification procedure.
In the last step, the investigation of the identification procedure was carried out using real
measurement data. On the one hand, the experimental results show a high performance of the
presented method for identification of clutch characteristics. On the other hand, potential for
advanced research works in the field of identification of transmission behavior of friction
clutches was detected
Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress
Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018
Proceedings of the NASA Conference on Space Telerobotics, volume 3
The theme of the Conference was man-machine collaboration in space. The Conference provided a forum for researchers and engineers to exchange ideas on the research and development required for application of telerobotics technology to the space systems planned for the 1990s and beyond. The Conference: (1) provided a view of current NASA telerobotic research and development; (2) stimulated technical exchange on man-machine systems, manipulator control, machine sensing, machine intelligence, concurrent computation, and system architectures; and (3) identified important unsolved problems of current interest which can be dealt with by future research
Mechanical Engineering
The book substantially offers the latest progresses about the important topics of the "Mechanical Engineering" to readers. It includes twenty-eight excellent studies prepared using state-of-art methodologies by professional researchers from different countries. The sections in the book comprise of the following titles: power transmission system, manufacturing processes and system analysis, thermo-fluid systems, simulations and computer applications, and new approaches in mechanical engineering education and organization systems
NASA Tech Briefs, May 1987
Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences