@article{SchudererRillSchaefferetal., author = {Schuderer, Matthias and Rill, Georg and Schaeffer, Thomas and Schulz, Carsten}, title = {Friction modeling from a practical point of view}, series = {Multibody System Dynamics}, journal = {Multibody System Dynamics}, publisher = {Springernature}, issn = {1384-5640}, doi = {10.1007/s11044-024-09978-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-72513}, pages = {18}, abstract = {AbstractRegularized static friction models have been used successfully for many years. However, they are unable to maintain static friction in detail. For this reason, dynamic friction models have been developed and published in the literature. However, commercial multibody simulation packages such as Adams, RecurDyn, and Simpack have developed their own specific stick-slip models instead of adopting one of the public domain approaches. This article introduces the fundamentals of these commercial models and their behavior from a practical point of view. The stick-slip models were applied to a simple test model and a more sophisticated model of a festoon cable system using their standard parameters.}, language = {en} } @misc{SchudererRillSchaefferetal., author = {Schuderer, Matthias and Rill, Georg and Schaeffer, Thomas and Schulz, Carsten}, title = {Friction modeling from a practical point of view}, series = {MULTIBODY2023: 11th ECCOMAS Thematic Conference on Multibody Dynamics, Tampa, 24th-28th May 2023}, journal = {MULTIBODY2023: 11th ECCOMAS Thematic Conference on Multibody Dynamics, Tampa, 24th-28th May 2023}, language = {en} } @misc{RueckBierlLechneretal., author = {R{\"u}ck, Thomas and Bierl, Rudolf and Lechner, Alfred and Graf, Antonia and Dams, Florian and Schreiner, Rupert and Auchter, Eberhard and Kriz, Willy and Deubzer, MIchael and Schiller, Frank and Mottok, J{\"u}rgen and Niemetz, Michael and Margull, Ulrich and Hagel, Georg and Utesch, Matthias and Waldherr, Franz and B{\"o}hm, Matthias and Fraunhoffer, Judith and Gardeia, Armin and Schneider, Ralph and Streubel, Janet and Landes, Dieter and Studt, Reimer and Peuker, Dominik and Scharfenberg, Georg and Hook, Christian and Schuster, Dietwald and Ehrlich, Ingo and Dinnebier, Heinrich and Briem, Ulrich and L{\"a}mmlein, Stephan and Koder, Alexander and Bialek, Adam and Genewsky, Axel and Neumeier, Michael and Schlosser, Philipp and Rabl, Hans-Peter and Paule, Matthias and Galster, Christoph and Schiedermeier, Michael and Zwickel, Andreas and Hobmeier, Christoph and Bischoff, Tobias and Rill, Georg and Schaeffer, Thomas and Arbesmeier, Martin and Groß, Andreas and Schlegl, Thomas and Becker, Mark and Senn, Konrad and Schliekmann, Claus and Scholz, Peter and Sippl, Christian and Grill, Martin}, title = {Forschungsbericht 2011 / Hochschule f{\"u}r Angewandte Wissenschaften - Fachhochschule Regensburg}, editor = {Eckstein, Josef}, address = {Regensburg}, organization = {Hochschule f{\"u}r Angewandte Wissenschaften Regensburg}, issn = {1868-3533}, doi = {10.35096/othr/pub-732}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7321}, language = {de} } @article{RillSchuderer, author = {Rill, Georg and Schuderer, Matthias}, title = {A Second-Order Dynamic Friction Model Compared to Commercial Stick-Slip Models}, series = {Modelling}, volume = {4}, journal = {Modelling}, number = {3}, publisher = {MDPI}, issn = {2673-3951}, doi = {10.3390/modelling4030021}, pages = {366 -- 381}, abstract = {Friction has long been an important issue in multibody dynamics. Static friction models apply appropriate regularization techniques to convert the stick inequality and the non-smooth stick-slip transition of Coulomb's approach into a continuous and smooth function of the sliding velocity. However, a regularized friction force is not able to maintain long-term stick. That is why dynamic friction models were developed in recent decades. The friction force depends herein not only on the sliding velocity but also on internal states. The probably best-known representative, the LuGre friction model, is based on a fictitious bristle but realizes a too-simple approximation. The recently published second-order dynamic friction model describes the dynamics of a fictitious bristle more accurately. It is based on a regularized friction force characteristic, which is continuous and smooth but can maintain long-term stick due to an appropriate shift in the regularization. Its performance is compared here to stick-slip friction models, developed and launched not long ago by commercial multibody software packages. The results obtained by a virtual friction test-bench and by a more practical festoon cable system are very promising. Thus, the second-order dynamic friction model may serve not only as an alternative to the LuGre model but also to commercial stick-slip models.}, language = {en} } @unpublished{RillSchuderer, author = {Rill, Georg and Schuderer, Matthias}, title = {A Second Order Dynamic Friction Model Compared to Commercial Stick-Slip Models}, doi = {10.20944/preprints202306.1233.v1}, abstract = {Friction has long been an important issue in multibody dynamics. Static friction models apply appropriate regularization techniques to convert the stick inequality and the non-smooth stick-slip transition of Coulomb's approach into a continuous and smooth function of the sliding velocity. However, a regularized friction force is not able to maintain long-term stick. That is why, dynamic friction models were developed in the last decades. The friction force depends herein not only on the sliding velocity but also on internal states. The probably best known representative, the LuGre friction model, is based on a fictitious bristle but realizes a too simple approximation. The recently published second order dynamic friction model describes the dynamics of a fictitious bristle more accurately. Its performance is compared here to stick-slip friction models, developed and launched not long ago by commercial multibody software packages.}, language = {en} } @article{RillSchaefferSchuderer, author = {Rill, Georg and Schaeffer, Thomas and Schuderer, Matthias}, title = {LuGre or not LuGre}, series = {Multibody System Dynamics}, journal = {Multibody System Dynamics}, publisher = {Springer}, doi = {10.1007/s11044-023-09909-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-65653}, pages = {28}, abstract = {The LuGre model is widely used in the analysis and control of systems with friction. Recently, it has even been made available in the commercial multibody dynamics simulation software system Adams. However, the LuGre model exhibits well-known drawbacks like too low and force rate-dependent break-away forces, drift problems during sticking periods, and significant differences in non-stationary situations between the pre-defined friction law and the one produced by the LuGre model. In the present literature, these problems are supposed to come from the model dynamics or its nonlinear nature. However, most of these drawbacks are not simple side effects of a dynamic friction model but are caused in the LuGre approach, as shown here, by a too simple and inconsistent model of the bristle dynamics. Standard examples and a more practical application demonstrate that the LuGre model is not a "what you see is what you get" approach. A dynamic friction model with accurate bristle dynamics and consistent friction force is set up here. It provides insight into the physical basis of the LuGre model dynamics. However, it results in a nonlinear and implicit differential equation, whose solution will not be easy because of the ambiguity of the friction characteristics. The standard workaround, a static model based on simple regularized characteristics, produces reliable and generally satisfactory results but definitely cannot maintain a stick. The paper presents a second-order dynamic friction model, which may serve as an alternative. It can maintain a stick and produces realistic and reliable results.}, language = {en} } @unpublished{RillSchaefferSchuderer, author = {Rill, Georg and Schaeffer, Thomas and Schuderer, Matthias}, title = {LuGre or not LuGre}, doi = {10.21203/rs.3.rs-2266522/v1}, abstract = {The LuGre model is widely used in the analysis and control of systems with friction. Recently, it has even been made available in the commercial multibody dynamics simulation software system Adams. However, the LuGre model exhibits well-known drawbacks like, too low and force rate dependent break-away forces, drift problems during sticking periods, and significant differences in non-stationary situations between the pre-defined friction law and the one produced by the LuGre model. In the present literature, these problems are supposed to come from the model dynamics or its nonlinear nature. However, most of these drawbacks are not simple side effects of a dynamic friction model but are caused in the LuGre approach, as shown here, by a too simple and inconsistent model of the bristle dynamics. Standard examples and a more practical application demonstrate, that the LuGre model is not a "what you see is what you get" approach. A dynamic friction model with accurate bristle dynamics and consistent friction force is set up here. It provides insight into the physical basis of the LuGre model dynamics. However, it results in a nonlinear and implicit differential equation, whose solution will not be easy because of the ambiguity of the friction characteristics. The standard workaround, a static model based on a simple regularized characteristics, produces reliable and generally satisfactory results, but definitely cannot maintain stick. The paper presents a second order dynamic friction model, which may serve as an alternative. It can maintain stick and produces realistic and reliable results.}, language = {en} } @book{RillSchaefferBorchsenius, author = {Rill, Georg and Schaeffer, Thomas and Borchsenius, Fredrik}, title = {Grundlagen und computergerechte Methodik der Mehrk{\"o}rpersimulation}, publisher = {Springer Nature}, doi = {10.1007/978-3-658-41968-4}, pages = {XIV, 260}, abstract = {Dieses Lehr- und {\"U}bungsbuch vermittelt auf anschauliche Weise die Methoden der Mehrk{\"o}rpersimulation und verdeutlicht deren Vor- und Nachteile bei der praktischen Anwendung anhand konkreter Beispiele. Die einzelnen Methoden werden durch Matlab-Skripte und -Funktionen verdeutlicht, wobei die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer K{\"o}rper die Schwerpunkte bilden. Die vorliegende Auflage wurde unter anderem um Matlab-Live-Skripte erweitert, welche kleine Animationen zur Veranschaulichung der Dynamik der Probleme enthalten. Die L{\"o}sungen zu den {\"U}bungsbeispielen und die integrierten Matlab-Skripte sowie weitere Beispiele und Anwendungen stehen {\"u}ber QR-Codes zum Download zur Verf{\"u}gung und erm{\"o}glichen dadurch auch ein effizientes Selbststudium.}, subject = {Mehrk{\"o}rpersystem}, language = {de} } @book{RillSchaefferBorchsenius, author = {Rill, Georg and Schaeffer, Thomas and Borchsenius, Fredrik}, title = {Grundlagen und computergerechte Methodik der Mehrk{\"o}rpersimulation}, edition = {4. Aufl.}, publisher = {Springer Fachmedien}, address = {Wiesbaden}, isbn = {978-3-658-28911-9}, doi = {10.1007/978-3-658-28912-6}, abstract = {Dieses Lehrbuch stellt die Methoden der Mehrk{\"o}rpersimulation anschaulich dar und erl{\"a}utert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer K{\"o}rper bilden dabei die Schwerpunkte. Konkrete Beispiele beinhalten einen Bungee-Sprung, die Eigendynamik eines Traktors mit Vorderachsfederung, das Hubschrauberrotorblatt sowie eine Pkw-Vorderachse. Die L{\"o}sungen zu den {\"U}bungsaufgaben und die im Text integrierten Matlab-Beispiele, die zum Teil durch Animationen angereichert sind, sowie zus{\"a}tzliche Beispiele und Anwendungen stehen auf der Verlagshomepage beim Buch zum Download zur Verf{\"u}gung und erm{\"o}glichen dadurch auch ein effizientes Selbststudium.}, language = {de} } @incollection{RillSchaefferBorchsenius, author = {Rill, Georg and Schaeffer, Thomas and Borchsenius, Fredrik}, title = {Analyse von Mehrk{\"o}rpersystemen}, series = {Grundlagen und computergerechte Methodik der Mehrk{\"o}rpersimulation}, booktitle = {Grundlagen und computergerechte Methodik der Mehrk{\"o}rpersimulation}, publisher = {Springer}, doi = {10.1007/978-3-658-41968-4_5}, pages = {198}, abstract = {Nach dem Aufbau eines Mehrk{\"o}rper-Simulationsmodells muss dieses auf Richtigkeit, Funktionalit{\"a}t und Wirtschaftlichkeit getestet werden. Die Ermittlung der Gleichgewichtslage stellt dabei eine erste Plausibilit{\"a}ts-Kontrolle dar. Eine Linearisierung mit anschließender Analyse der Eigendynamik liefert Aussagen {\"u}ber die Frequenzen und das D{\"a}mpfungsverhalten des Modells. Einfache Erregersignale erm{\"o}glichen einen ersten Einblick in das nichtlineare dynamische Verhalten des Modells. Modell-Parameter, die nicht genau bekannt sind, k{\"o}nnen durch gezielte Variationen plausibel gesch{\"a}tzt oder {\"u}ber eine Optimierung sogar mit optimalen Werten belegt werden. Nach all diesen Tests steht das Mehrk{\"o}rper- Simulationsmodell dann f{\"u}r praktischeUntersuchungen zurVerf{\"u}gung, die neben reinen Zeitsimulationen auch Methoden der Inversen Kinematik und der Inversen Dynamik mit einschließen.}, language = {de} } @book{RillSchaeffer, author = {Rill, Georg and Schaeffer, Thomas}, title = {Grundlagen und Methodik der Mehrk{\"o}rpersimulation : Vertieft in Matlab-Beispielen, {\"U}bungen und Anwendungen}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-658-06084-8}, pages = {215}, abstract = {Dieses Lehrbuch vermittelt nicht nur Grundlagen, sondern stellt auch die Methoden der Mehrk{\"o}rpersimulation anschaulich dar und erl{\"a}utert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden und erm{\"o}glichen es, Aufwand und Problematik bei der Umsetzung der Theorie innerhalb von Simulationsprogrammen einzusch{\"a}tzen. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer K{\"o}rper bilden dabei die Schwerpunkte. Konkret behandelte Beispiele sind die Eigendynamik eines Traktors mit gefederter Vorderachse, das Rotorblatt eines Hubschraubers sowie die Vorderachse eines Pkws. Die entsprechenden Matlab-Skripte und L{\"o}sungen zu den {\"U}bungsaufgaben k{\"o}nnen auf der Springer-Homepage beim Buch heruntergeladen werden. Der Inhalt Dynamik des starren K{\"o}rpers - Bewegungsgleichungen - Starre K{\"o}rper mit elastischen und kinematischen Verbindungselementen - Integrationsverfahren - Rekursiver Algorithmus - Differential-Algebraische Gleichungen - Analyse von Mehrk{\"o}rpersystemen - Anwendungs- und {\"U}bungsbeispiele aus der Technik Die Zielgruppen Studenten des Maschinenbaus, der Elektrotechnik und Mechatronik sowie der Biomechanik an Hochschulen und Universit{\"a}ten Ingenieure in der Praxis, die sich mit Fragestellungen der Mehrk{\"o}rpersimulation (MKS) befassen Entwickler aus der Kfz-Technik sowie Fachleute aus F+E Die Autoren Dr.-Ing. Georg Rill ist Professor mit den Lehrgebieten Technische Mechanik, Ingenieurinformatik, Fahrdynamik, Mehrk{\"o}rperdynamik sowie Laborleiter Fahrdynamik. Dr.-Ing. Thomas Schaeffer ist Professor mit den Lehrgebieten Konstruktion, CAD, Maschinenelemente und Getriebetechnik, Mehrk{\"o}rpersysteme und Bewegungstechnik sowie Laborleiter Mehrk{\"o}rpersimulation, beide an der Ostbayerischen Technischen Hochschule (OTH) Regensburg.}, language = {de} } @book{RillSchaeffer, author = {Rill, Georg and Schaeffer, Thomas}, title = {Grundlagen und Methodik der Mehrk{\"o}rpersimulation}, edition = {3. Aufl.}, publisher = {Springer}, address = {Wiesbaden}, isbn = {978-3-658-16008-1}, doi = {10.1007/978-3-658-16009-8}, abstract = {Dieses Lehrbuch stellt die Methoden der Mehrk{\"o}rpersimulation anschaulich dar und erl{\"a}utert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer K{\"o}rper bilden dabei die Schwerpunkte. Konkrete Beispiele beinhalten die Eigendynamik eines Traktors mit Vorderachsfederung, das Hubschrauberrotorblatt sowie eine Pkw- Vorderachse. Die entsprechenden Matlab-Skripte und L{\"o}sungen zu den {\"U}bungsaufgaben k{\"o}nnen auf der Springer-Homepage beim Buch heruntergeladen werden. Neu aufgenommen wurden SparseMatrix Operationen sowie ein Beispiel zu einfach geschlossenen kinematischen Schleifen.}, language = {de} } @article{RillBauerTopcagic, author = {Rill, Georg and Bauer, Florian and Topcagic, Edin}, title = {Performance of leaf spring suspended axles in model approaches of different complexities}, series = {Vehicle System Dynamics}, volume = {60}, journal = {Vehicle System Dynamics}, number = {8}, publisher = {Taylor\&Francis}, doi = {10.1080/00423114.2021.1928249}, pages = {2871 -- 2889}, abstract = {Axles with leaf spring suspension systems are still a popular choice in many commercial vehicles. However, leaf springs are not in perfect conformity to standard multibody vehicle models because they combine guidance and suspension in one single element. Combining standard multibody vehicle models with sophisticated finite element leaf spring models results in rather complex and computing time-consuming solutions. Purely kinematic models, defined by lookup tables or the design kinematics approach, cover only some but not all features of the leaf spring suspension. As shown here, the five-link model, which incorporates a quasi-static solution of the leaf spring compliance, provides a very practical model. It is comparatively lean and provides results of sufficient accuracy in the whole application range.}, language = {en} } @article{RillBauerKirchbeck, author = {Rill, Georg and Bauer, Florian and Kirchbeck, Mathias}, title = {VTT - a virtual test truck for modern simulation tasks}, series = {Vehicle system dynamics}, volume = {59}, journal = {Vehicle system dynamics}, number = {4}, publisher = {Taylor\&Francis}, doi = {10.1080/00423114.2019.1705356}, pages = {635 -- 656}, abstract = {The development of new technologies like advanced driver assistance systems or automated driving requires a flexible simulation environment of sufficient complexity. In general this flexibility is not provided by commercial software packages. This paper presents a three-dimensional and nonlinear hand-made model for heavy commercial vehicles including tractor and trailer as well as tractor and semitrailer combinations that can be used in different simulation environments, as well as in real-time applications. As typical for trucks, the torsional flexibility of the frame and a suspended driver's cabin are taken into account. The design kinematics makes it possible to handle different and quite complex axle suspensions very efficiently. Appropriate force elements are used to model various couplings between tractor and trailer or tractor and semitrailer, respectively. The virtual test truck environment (VTT) coded in ANSI C is extremely portable and can easily be embedded in commercial simulation packages like MATLAB/Simulink. It includes the TMeasy tyre model and offers flexible interfaces to third-party software tools.}, language = {en} } @inproceedings{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {A Novel Approach for Parametrization of Suspension Kinematics}, series = {Advances in Dynamics of Vehicles on Roads and Tracks: Proceedings of the 26th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2019), August 12-16, 2019, Gothenburg, Sweden}, booktitle = {Advances in Dynamics of Vehicles on Roads and Tracks: Proceedings of the 26th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2019), August 12-16, 2019, Gothenburg, Sweden}, editor = {Klomp, Matthijs and Bruzelius, Fredrik and Nielsen, Jens and Hillemyr, Angela}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-38076-2}, doi = {10.1007/978-3-030-38077-9_210}, pages = {1848 -- 1857}, abstract = {n the automotive industry, simulations are needed to analyse the dynamics of vehicles and also of its main components and subsystems, e.g. tires, brakes and suspension systems. These simulations are required for an early-stage development and in consequence, they must deliver realistic results. Suspension systems plays a key role in comfort and safety of road vehicles. They usually consist of rigid links and force elements that are arranged with a specific topology. In addition, some of their functionalities are to carry the weight of the car and the passengers, and maintain a correct wheel alignment. In simulations involving suspension systems, lookup-tables are frequently used. They are obtained from a Kinematic and Compliance (KnC) test and then standardized for a specific vehicle simulation software. Nonetheless, lookup-tables require a reasonable number of characteristic points. Additionally, derivatives, interpolation, and extrapolation are not necessarily smooth. This produces results that depend on the interpolation technique and may be inaccurate. In this paper, a novel method called "design kinematics" is proposed. This method can describe the kinematic properties of almost any type of suspension systems. Comparisons with an analytic calculation and a KnC measurement shown that the design kinematics is able to represent the kinematic and compliance properties of suspension systems extremely well and very efficiently.}, language = {en} } @inproceedings{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {The Influence of Axle Kinematics on Vehicle Dynamics}, series = {Interdisciplinary Applications of Kinematics. Proceedings of the Third International Conference (IAK)}, volume = {71}, booktitle = {Interdisciplinary Applications of Kinematics. Proceedings of the Third International Conference (IAK)}, editor = {Kecskem{\´e}thy, Andr{\´e}s and Geu Flores, Francisco and Carrera, Eliodoro and Elias, Dante A.}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-16422-5}, doi = {10.1007/978-3-030-16423-2_2}, pages = {23 -- 31}, abstract = {The automotive industry employs many different kinds of axle suspension systems at modern passenger cars. Important criteria are costs, space requirements, kinematic properties, and compliance attributes. This paper illustrates that in particular the kinematic properties of a suspension system have a significant influence on the dynamics of vehicles. As a consequence, the kinematics of a suspension system must be modeled very precisely and nonlinear. Typical kinematical features of a suspension system are discussed by analyzing the most common double wishbone axle suspension system. The influence of the axle kinematics on vehicle dynamics is finally demonstrated by simulation results generated with a fully nonlinear and three-dimensional multibody vehicle model.}, language = {en} } @book{RillArrietaCastro, author = {Rill, Georg and Arrieta Castro, Abel}, title = {Road Vehicle Dynamics}, publisher = {CRC Press}, address = {Boca Raton, Fla.}, isbn = {9780429244476}, doi = {10.1201/9780429244476}, abstract = {Road Vehicle Dynamics: Fundamentals and Modeling with MATLAB®, Second Edition combines coverage of vehicle dynamics concepts with MATLAB v9.4 programming routines and results, along with examples and numerous chapter exercises. Improved and updated, the revised text offers new coverage of active safety systems, rear wheel steering, race car suspension systems, airsprings, four-wheel drive, mechatronics, and other topics. Based on the lead author's extensive lectures, classes, and research activities, this unique text provides readers with insights into the computer-based modeling of automobiles and other ground vehicles. Instructor resources, including problem solutions, are available from the publisher.}, subject = {Fahrdynamik}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {A Three-Dimensional and Nonlinear Virtual Test Car}, series = {ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France}, booktitle = {ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France}, address = {Lyon}, pages = {49 -- 58}, abstract = {Virtual testing procedures have become a standard in vehicle dynamics. The increasing complexity of driver assistance sys- tems demand for more and more virtual tests, which are supposed to produce reliable results even in the limit range. As a consequence, simplified vehicle models, like the classical bicycle model or 4-wheel vehicle models, have to be replaced by a fully three-dimensional and nonlinear vehicle model, which also encompasses the details of the suspension systems. This paper presents a passenger car model, where the chassis, the four knuckles, and the four wheels are described by rigid bodies, the suspension system is modeled by the generic design kinematics, and the TMeasy tire model provides the tire forces and torques in all driving situations.}, language = {en} } @article{Rill, author = {Rill, Georg}, title = {Sophisticated but quite simple contact calculation for handling tire models}, series = {Multibody system dynamics}, volume = {45}, journal = {Multibody system dynamics}, number = {2}, publisher = {Springer Nature}, organization = {SPRINGER}, doi = {10.1007/s11044-018-9629-4}, pages = {131 -- 153}, abstract = {Handling tire models like Pacejka (Tire and Vehicle Dynamics, 3rd edn., Elsevier, Amsterdam, 2012) or TMeasy (Rill in Proc. of the XV Int. Symp. on Dynamic Problems of Mechanics, Buzios, RJ, Brazil, 2013) consider the contact patch as one coherent plane. As a consequence, the irregularities of a rough road profile must be approximated by an appropriate local road plane that serves as an effective road plane in order to calculate the geometric contact point and the corresponding contact velocities. The Pacejka/SWIFT tire model employs a road enveloping model that generates the effective height and slope by elliptical cams. TMeasy just uses four representative road points for that purpose. In addition, TMeasy replaces the geometric contact point by the static contact point and shifts it finally to the dynamic contact point that represents the point where the contact forces are applied. In doing so, a rather sophisticated but still simple contact calculation is possible. Simulations obtained with a virtual tire test rig and fully nonlinear three-dimensional multibody system models of a motor-scooter and a passenger car demonstrate the potential of this contact approach.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {TMeasy 6.0-A handling tire model that incorporates the first two belt eigenmodes}, series = {Proceedings of the XI International Conference on Structural Dynamics (EURODYN 2020): Athens, Greece, 23.11.2020 - 26.11.2020}, booktitle = {Proceedings of the XI International Conference on Structural Dynamics (EURODYN 2020): Athens, Greece, 23.11.2020 - 26.11.2020}, publisher = {EASD Procedia}, doi = {10.47964/1120.9054.18673}, pages = {676 -- 689}, abstract = {TMeasy 6.0, an extension to the standard TMeasy tire model of version 5.3, takes the relevant first two rigid body eigenmodes of the belt into consideration. These modes represent the in plane longitudinal and rotational movements of the belt relative to the rim. The dynamics of the longitudinal force is of higher order then and reproduces the tire wheel vibrations, required for indirect tire-pressure monitoring systems (iTPMS), sufficiently well. A tailored implicit solver, which takes the stiff coupling between the longitudinal force and the belt motions into account, still provides real-time performance in addition. Simulation examples show that a rigid body vehicle model equipped with TMeasy 6.0 makes it possible to investigate second generation indirect tire-pressure monitoring systems.}, language = {en} }