Combined shifting for automatic transmissions for commercial vehicles

Die vorliegende Arbeit beschäftigt sich mit der Gruppenschaltungsansteuerung von Nutzfahrzeuggetrieben. Gruppengetriebe, d.h. in Reihe geschaltete Getrie-be, sind bei Nutzfahrzeugschaltgetrieben weit verbreitet. Es wird dann von Gruppenschaltungen gesprochen, wenn zwei in Reihe geschaltete Getriebe gleichzeitig die Übersetzung wechseln. Wird während der Schaltung die Last von der Getriebeeingangswelle genommen, handelt es sich um eine technisch beherrschbare Aufgabe. Bei Automatikgetrieben wird der Übersetzungswechsel aber mit anliegender Eingangslast ausgeführt. Die Automatikgetriebe zählen zur Kategorie der Lastschaltgetriebe. Bei Nutzfahrzeugautomatikgetrieben werden bisher Gruppenschaltungen vermieden, da die Ansteuerung der Kupplungen und Bremsen auch ohne Gruppenschaltung bereits anspruchsvoll ist. Die vorliegen-de Arbeit hat zum Ziel, den Gruppenwechsel unter dem Gesichtspunkt der Zug-kraftschaltung beherrschbar zu machen. Die Arbeit umfasst drei wesentliche Schwerpunkte. Hierzu zählt die Erstellung eines Getriebeprogramms für die Antriebsstrangstreckensimulation, die Optimie-rung der Übersetzungswechsel mit einem auf die Fragestellung angepassten Optimierungsprogramm und die Auslegungsempfehlungen für die Ansteuerung des Übersetzungswechsels in Automatikgetrieben. Aufgrund eines fehlenden Simulationswerkzeugs zu Beginn der Arbeit wurde für die Beantwortung des Ge-triebeverhaltens im Übersetzungswechsel ein entsprechendes Getriebepro-gramm entwickelt. Das Getriebeprogramm arbeitet als Unterprogramm innerhalb einer Basisantriebsstrangsimualtion für Streckensimulation und wurde so gestal-tet, dass beliebige Planetengetriebeanordnungen modelliert werden können. Aus der großen Anzahl von Simulationsrechnungen wurden Auslegungsempfeh-lungen für die Steuerung des Übersetzungswechsels abgeleitet. Das zeitlich sehr empfindliche Verhalten von Gruppenschaltungen führt zu einem Lösungs-ansatz mit Kennfeldern. Durch das Vorhalten optimierter Überdeckungen für un-terschiedliche Schaltausgangsvoraussetzungen mit Hilfe von Kennfeldern konn-te die Gruppenschaltung auch unter dem Aspekt der Zugkraftschaltung beherrschbar gemacht werden.Product development according to current aspects cannot afford to neglect the customer's requirements. This influences the economical success of a product significantly. The technical solution must be based on the customer's requirements but without neglecting the basic demands which apply to every gearbox. The behaviour of the automatic transmission during a gearshift is of vital importance to the customer and can become the most important criterion when considering whether or not to purchase. Further main tasks of the automatic transmission are the automatic gear selection taking into consideration the efficiency, the power and the driver's wishes. In this case it is a question of fundamental technical requirements without which a product will not be successful. With an automatic transmission it is easier to drive a vehicle with the result that road safety is improved. The demands on the automatic transmissions show that the automatic control is of great significance. This thesis is largely concerned with the gear control. Via sensors, the gear control receives information regarding the state of the vehicle and the driver's requirements. With the input variables considering the shift-strategy, the output variables are determined. This process is taken over by the control program and/or the shift point control. In this way the control program determines the time of the gearshift. The gear steering has a further program which is called the shift quality control. The shift quality control activates the hydraulic valves and actually performs the gear ratio change. The design of the shift quality control is the nucleus of this thesis. Emphases of the thesis The thesis concentrates on three main points: the preparation of a detailed gear model for the power train simulation, the optimization of the gear shifting and the design recommendations for the timing of the gear shifting in automatic transmissions. Gear model The gear model enables the arbitrary arrangement of elementary planetary gearing on a modular basis. Additionally, the gear model makes it possible to illustrate the gear shifting without restrictions. Furthermore, the model preparation was influenced by the standards of the basic simulation. Because of this, the solution algorithm must be adapted to suit the basic simulation. The gearbox can be built up from six basic elements in any way required. The elements are a hydrodynamic torque converter, open elementary planetary gearing, clutches, free wheels, supplies and nodes. The hydrodynamic torque converter is the typical driving element of the automatic transmission. The elementary planetary gearing leads and changes torque and rotation speed. The clutches change the ratio. Free-wheels are exclusively used in the torque converter. The supplies lead the driving power to the relevant power train, or connect to the case of the gear box. The nodes link the different gear elements to each other. This structure can simulate automatic transmissions with arbitrary arrangement under realistic conditions, also during the gearshift. Optimization The optimization algorithm supports the calculation of the variants during the structuring. Afterwards it calculates the variants automatically in a so-called batch mode. The variation is carried out according to the chronological overlap of the acting clutches. That means that the opening and locking times are changed automatically. After the calculation the results are evaluated automatically. Basically this is a question of screening the results from the variation calculation. The procedure used here, the least squares method, means that evaluations can be carried out for several results. The procedure of the least squares method computes the deviations of a simulated process from an ideal previously defined. The optimization algorithm allows the objective classification of the shift-quality. Design recommendations The optimization calculation proved the sensitive behaviour of the gear change, particularly with group shifts. The design recommendations concern the chronological overlap, the pressure functions as well as the amount of the design pressure during the slipping time. These design recommendations are formulated in a general manner, although the object of consideration is the gearbox. Furthermore, design recommendations were formulated for group shifting and their chronological activation. The behaviour of the group shifting is very sensitive. Optimized characteristic diagrams can solve this sensitive behaviour. The optimized characteristic diagrams must be set up ready for the respective operational status of vehicles

Holistic Testing Strategies for Electrified Vehicle Powertrains in Product Development Process

In the field of powertrain engineering, longstanding knowledge was gained for testing conventional vehicle powertrains. The hitherto used test strategies here were more focused on the subsystems of the powertrain than on the powertrain as an integrated system. Through the electrification of the powertrain, the topology and the range of functions have changed. This leads to new challenges for the validation and requires not only adjustments of the test strategies for electric vehicle powertrains but establish and develop integrative tests for the powertrain as an integrated system in order to meet the increased complexity. This paper presents a method to develop a holistic test strategy for a hybrid and electrical vehicle powertrain. In order to avoid misunderstandings of the used terms, it is necessary to create a standard understanding of them. Therefore, a nomenclature is defined and described. Furthermore, a definition of a holistic test strategy is provided. The focus of this present study is on the powertrain and not on its single subsystems. Subsequently, the four steps of the method are introduced and the current results are presented. Finally, a new developed test element within the holistic test strategy is introduced. The findings of this study support the integrative testing for powertrains

Die Militärakademie in der demokratischen Revolution 1989/90: Aufbruch und Ende

Abschließende DSS e.V.-Dokumentation zur Militärakademie ´Friedrich Engels´ (1959-1990).:Wolfgang Scheler, Vorwort. Wolfgang Scheler, Die Militärakademie in der demokratischen Revolution und Militärreform. Eberhard Haueis, Wolfgang Scheler, Die Militärakademie im Ringen um Konversion. Siegfried Schönherr, Der Lehrstuhl Wirtschaftswissenschaften in den Wendemonaten. Rainer Böhme, Operative Lehre und Forschung an der Militärakademie zwischen neuer Militärdoktrin und Militärreform (1987-1990). Eberhard Haueis, Die Auflösung der Militärakademie Dresden. Hans-Werner Liebig, Erinnerungsbericht als Mitglied der Unterstützungsgruppe zur Auflösung der NVA-Militärakademie 'Friedrich Engels' in Dresden Nachgereichte Beiträge zu: Militärakademie ´Friedrich Engels´, Historisch-kritische Nachbetrachtung zum 50. Jahrestag ihrer Gründung, DSS-Arbeitspapiere, Heft 95/2009: Heinz Weidner, Zur Rolle der Politabteilung der Militärakademie Friedrich Engels in den 1970er und 1980er Jahren. Reinhard Klos, Erinnerungen an meinen Dienst als Offizier im Politorgan der Militärakademie ´Friedrich Engels´. Autore

Die Militärakademie in der demokratischen Revolution 1989/90: Aufbruch und Ende

Abschließende DSS e.V.-Dokumentation zur Militärakademie ´Friedrich Engels´ (1959-1990).:Wolfgang Scheler, Vorwort. Wolfgang Scheler, Die Militärakademie in der demokratischen Revolution und Militärreform. Eberhard Haueis, Wolfgang Scheler, Die Militärakademie im Ringen um Konversion. Siegfried Schönherr, Der Lehrstuhl Wirtschaftswissenschaften in den Wendemonaten. Rainer Böhme, Operative Lehre und Forschung an der Militärakademie zwischen neuer Militärdoktrin und Militärreform (1987-1990). Eberhard Haueis, Die Auflösung der Militärakademie Dresden. Hans-Werner Liebig, Erinnerungsbericht als Mitglied der Unterstützungsgruppe zur Auflösung der NVA-Militärakademie 'Friedrich Engels' in Dresden Nachgereichte Beiträge zu: Militärakademie ´Friedrich Engels´, Historisch-kritische Nachbetrachtung zum 50. Jahrestag ihrer Gründung, DSS-Arbeitspapiere, Heft 95/2009: Heinz Weidner, Zur Rolle der Politabteilung der Militärakademie Friedrich Engels in den 1970er und 1980er Jahren. Reinhard Klos, Erinnerungen an meinen Dienst als Offizier im Politorgan der Militärakademie ´Friedrich Engels´. Autore

Straightening of superconducting HERA dipoles for the any-light-particle-search experiment ALPS II

At DESY the ALPS II experiment is being installed in the HERA tunnel to search for axion like particles. A laser beam will be injected into the magnetic field of a string of superconducting (s.c.) dipole magnets, available from the HERA proton storage ring, to produce axion like particles. After passing a light tight wall, the ALPs can reconvert into photons in a second string of HERA s.c. dipoles. The sensitivity of the experiment will be increased by two mode-matched optical cavities before and behind the wall. The dipoles for the HERA storage ring are curved, suited for stored proton beam. However, the curvature of the magnets limits the aperture and hence the performance of theoptical resonators beyond a certain length. As the sensitivity of the search scales with the length of the magnetic field, the aperture for the optical resonators inside the HERA dipoles was increased by straightening the curved magnet yoke. The procedure of straightening the s.c. HERA dipoles is described in this report

Straightening of Superconducting HERA Dipoles for the Any-Light-Particle-Search Experiment ALPS II

At DESY the ALPS II experiment is being installed in the HERA tunnel to search for axion like particles (ALPs). A laser beam will be injected into a string of superconducting HERA dipole magnets, to produce ALPs. After passing a light tight wall, the ALPs can reconvert into photons in a second string of HERA dipoles.The sensitivity of the experiment will be increased by two mode-matched optical cavities before and behind the wall. The curvature of the magnets limits the performance of the optical resonators, Therefore the aperture for the optical resonators inside the HERA dipoles was increased by straightening the curved magnet yoke. The procedure of straightening the HERA dipoles is described in this report

Nongenomic Thyroid Hormone Signaling Occurs Through a Plasma Membrane–Localized Receptor

Thyroid hormone (TH) is essential for vertebrate development and the homeostasis of most adult tissues, including bone. TH stimulates target gene expression through the nuclear thyroid receptors TRα and TRβ; however, TH also has rapid, transcription-independent (nongenomic) effects. We found a previously uncharacterized plasma membrane-bound receptor that was necessary and sufficient for nongenomic TH signaling in several cell types. We determined that this receptor is generated by translation initiation from an internal methionine of TRα, which produces a transcriptionally incompetent protein that is palmitoylated and associates with caveolin-containing plasma membrane domains. TH signaling through this receptor stimulated a pro-proliferative and pro-survival program by increasing the intracellular concentrations of calcium, nitric oxide (NO), and cyclic guanosine monophosphate (cGMP), which led to the sequential activation of protein kinase G II (PKGII), the tyrosine kinase Src, and extracellular signal-regulated kinase (ERK) and Akt signaling. Hypothyroid mice exhibited a cGMP-deficient state with impaired bone formation and increased apoptosis of osteocytes, which was rescued by a direct stimulator of guanylate cyclase. Our results link nongenomic TH signaling to a previously uncharacterized membrane-bound receptor, and identify NO synthase, guanylate cyclase, and PKGII as TH effectors that activate kinase cascades to regulate cell survival and proliferation

Qualification of the Titanium Welds in the E-XFEL Cryomodule and the CE Certification

The CE stamping of the one hundred 1.3 GHz cryomodules for the European XFEL Linac is a main step in the process of the certification of the entire Linac as pressure equipment. Stringent requirements on materials and the quality of the welds of the pressurised components need to be satisfied to obtain the stamp. This paper summarizes these requirements, describes the process developed to qualify each module and summarises the rework campaign on the cavity helium vessels made necessary to obtain the required quality for a reliable and safe accelerator