BLACK BOX EFFICIENCY MODELLING OF AN ELECTRIC DRIVE UNIT UTILIZING METHODS OF MACHINE LEARNING

The increasing electrification of powertrains leads to increased demands for the test technology to ensure the required functions. For conventional test rigs in particular, it is necessary to have knowledge of the test technology's capabilities that can be applied in practical testing. Modelling enables early knowledge of the test rigs dynamic capabilities and the feasibility of planned testing scenarios. This paper describes the modelling of complex subsystems by experimental modelling with artificial neural networks taking transmission efficiency as an example. For data generation, the experimental design and execution is described. The generated data is pre-processed with suitable methods and optimized for the neural networks. Modelling is executed with different variants of the inputs as well as different algorithms. The variants compare and compete with each other. The most suitable variant is validated using statistical methods and other adequate techniques. The result represents reality well and enables the performance investigation of the test systems in a realistic manner

Unusual multisystemic involvement and a novel BAG3 mutation revealed by NGS screening in a large cohort of myofibrillar myopathies

Myofibrillar myopathies (MFM) are a group of phenotypically and genetically heterogeneous neuromuscular disorders, which are characterized by protein aggregations in muscle fibres and can be associated with multisystemic involvement.Methods We screened a large cohort of 38 index patients with MFM for mutations in the nine thus far known causative genes using Sanger and next generation sequencing (NGS). We studied the clinical and histopathological characteristics in 38 index patients and five additional relatives (n = 43) and particularly focused on the associated multisystemic symptoms.Results We identified 14 heterozygous mutations (diagnostic yield of 37%), among them the novel p.Pro209Gln mutation in the BAG3 gene, which was associated with onset in adulthood, a mild phenotype and an axonal sensorimotor polyneuropathy, in the absence of giant axons at the nerve biopsy. We revealed several novel clinical phenotypes and unusual multisystemic presentations with previously described mutations: hearing impairment with a FLNC mutation, dysphonia with a mutation in DES and the first patient with a FLNC mutation presenting respiratory insufficiency as the initial symptom. Moreover, we described for the first time respiratory insufficiency occurring in a patient with the p.Gly154Ser mutation in CRYAB. Interestingly, we detected a polyneuropathy in 28% of the MFM patients, including a BAG3 and a MYOT case, and hearing impairment in 13%, including one patient with a FLNC mutation and two with mutations in the DES gene. In four index patients with a mutation in one of the MFM genes, typical histological findings were only identified at the ultrastructural level (29%).Conclusions We conclude that extraskeletal symptoms frequently occur in MFM, particularly cardiac and respiratory involvement, polyneuropathy and/or deafness. BAG3 mutations should be considered even in cases with a mild phenotype or an adult onset. We identified a genetic defect in one of the known genes in less than half of the MFM patients, indicating that more causative genes are still to be found. Next generation sequencing techniques should be helpful in achieving this aim

A chemical survey of exoplanets with ARIEL

Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

Planet Formation Imager (PFI): science vision and key requirements

The Planet Formation Imager (PFI) project aims to provide a strong scientific vision for ground-based optical astronomy beyond the upcoming generation of Extremely Large Telescopes. We make the case that a breakthrough in angular resolution imaging capabilities is required in order to unravel the processes involved in planet formation. PFI will be optimised to provide a complete census of the protoplanet population at all stellocentric radii and over the age range from 0.1 to ~100 Myr. Within this age period, planetary systems undergo dramatic changes and the final architecture of planetary systems is determined. Our goal is to study the planetary birth on the natural spatial scale where the material is assembled, which is the "Hill Sphere" of the forming planet, and to characterise the protoplanetary cores by measuring their masses and physical properties. Our science working group has investigated the observational characteristics of these young protoplanets as well as the migration mechanisms that might alter the system architecture. We simulated the imprints that the planets leave in the disk and study how PFI could revolutionise areas ranging from exoplanet to extragalactic science. In this contribution we outline the key science drivers of PFI and discuss the requirements that will guide the technology choices, the site selection, and potential science/technology tradeoffs.S.K. acknowledges support from an STFC Rutherford Fellowship (ST/J004030/1) and Philip Leverhulme Prize (PLP-2013-110). Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration

Influences on the fatigue life of automatic transmission housings of buses

Aufgrund des weltweit steigenden Verkehrsaufkommens nimmt die Anzahl der Stadt- und Überlandbusse ständig zu. Stadtbusse weisen im Gegensatz zu anderen Fahrzeugarten einen charakteristischen Fahrzyklus auf, der durch häufige Beschleunigungs- und Verzögerungsvorgänge gekennzeichnet ist. Die Antriebsstrangkonfiguration, d. h. die Anordnung von Motor, Getriebe und angetriebenen Achsen von Bussen ist äußerst vielfältig. Daraus ergeben sich unterschiedliche Abtriebsvarianten für Getriebe, die in vielen Bussen zum Einsatz kommen sollen. Im Nutzfahrzeugbereich finden Automatgetriebe überwiegend in Stadtbussen ihre Anwendung. Die wesentlichen Gestaltungsmerkmale von Automatgetrieben werden ermittelt. Daraus wird der Aufbau eines Prinzipgehäuses abgeleitet. Des weiteren werden verschiedene Antriebsstrangkonfigurationen untersucht. Die Belastungen der Gehäuse sind insbesondere auf die Längsdynamik des Busses, auf Fahrbahnunebenheiten und auf Schwingungen zurückzuführen. Aufgrund der Längsdynamik entstehen am Getriebegehäuse Momente durch Kupplungen und den Retarder sowie Lager- und Stützkräfte. Der Einsatz eines Getriebetyps in unterschiedlichsten Fahrzeugen auf verschie-densten Strecken, führt zu einem breiten Belastungsspektrum der Bauteile. Neben der Drehmomentenkapazität des Motors sind für die Belastung der Getriebebauteile das Fahrzeuggewicht, die Achsübersetzung, das Schaltprogramm, die Topografie der Strecke und das Geschwindigkeitsprofil des Fahrzeugs von entscheidender Bedeutung. Hierzu ist die Bestimmung repräsen-tativer Streckendaten von großer Bedeutung. Basierend auf einer repräsentativen Anzahl an Messdaten bzgl. Topografie und Geschwindigkeit von realen Einsätzen werden die zeitabhängigen Belastungen sowie der Verbrauch und weitere Fahrparameter mittels Antriebsstrangsimulation ermittelt. Die Belastungen infolge von Lagerkräften, Kupplungsreaktionskräften und Retardermoment usw. werden an unterschiedlichen Stellen in unterschiedlichen Richtungen nicht proportional über der Zeit zueinander am Gehäuse abgestützt. Das bedeutet, dass eine mehrachsige Belastung vorliegt. Die Beanspruchungen werden mit Hilfe der Finiten-Element-Methode berechnet. Die Belastungen werden an den entsprechenden Stellen als Einheitslasten wirkend auf das Gehäuse bzw. die Anbauteile aufgebracht. Durch entsprechende Wahl der Lasten ist es möglich, z. B. dynamische Belastungen aufgrund des Schaltvorgangs in der Lebensdaueranalyse zu berücksichtigen. Die Beanspruchungen infolge multiaxialer Belastung werden für jeden Einheits-lastfall berechnet. Die Beanspruchung zu einem bestimmten Zeitpunkt wird durch Linearkombination der Beanspruchungen von den Einheitslastfällen mit den entsprechenden Lasten bestimmt. Die Kenntnis über den Zusammenhang zwischen Betriebsgröße und Bauteille-bensdauer hilft kritischere und weniger kritische Betriebsgrößen zu identifizieren sowie die Folgen der Änderung von Betriebsgrößen abzuschätzen. Unter anderem wurde der Einfluss der Durchschnittsgeschwindigkeit, die Anzahl der Stopps pro Kilometer, die Anzahl der Schaltungen, der Verbrauch, die Be-schleunigung, die Steigung und die Masse des Busses betrachtet. Der Einfluss verschiedener Abtriebsvarianten auf die Lebensdauer der Gehäuse wird außerdem betrachtet. Diese Parameter werden der Schädigung des Gehäuses gegenübergestellt um Korrelationen zu erkennen und die schädigungsverursachenden Betriebsgrößen zu ermitteln. Viele Stopps bzw. die Beschleunigungsphasen des Busses, die von einem Stopp ausgehen, führen zu einer hohen Gehäuseschädigung. Ein hoher Verbrauch tritt bei Strecken auf, bei denen eine hohe Schädigung am Gehäuse vorliegt. In einem vollbesetzten Bus wird das Gehäuse stärker beansprucht als in einem leeren Bus. In einem weiteren Schritt wird die Übertragbarkeit der Erkenntnisse auf Wellen und Zahnräder untersucht. Aus diesen Erkenntnissen heraus werden bauteilbezogene kritische Belastungskollektive für Gehäuse, Wellen und Zahnräder definiert. Als wesentliche Betriebsparameter für Busautomatgetriebe haben sich die Anzahl der Stopps, die Anzahl der Beschleunigungsvorgänge, die Steigung und die Gesamtmasse des Fahrzeugs herausgestellt. Ist ein Zusammenhang zwischen einem auf eine bestimmte Streckenlänge bezogenen Fahrparameter und der Bauteilschädigung erkennbar, kann ein Einheitszyklus definiert werden. Bei der Gegenüberstellung der bezogenen Fahrparameter und der bezogenen Schädigung muss ein kritischer Fahrparameter, wie z. B. die Anzahl der Stopps, entsprechend der Korrelation zwischen Fahrparameter und Schädigung definiert werden. Aufgrund der umfangreichen Untersuchungen ist es möglich, für die Getriebe-bauteile repräsentative Lastkollektive zu definieren. Als Grundlage hierfür diente der Zusammenhang unterschiedlicher Fahrparameter und der Schädigung verschiedener Getriebeteile. Durch die Definition entsprechender Einheitszyklen ist es möglich Versuchs- und Rechenzeiten zu reduzieren.A number of requirements are made on modern automatic transmissions. Low fuel consumption, small size and light weight have to be considered more and more in the development phase, along with a defined fatigue life and the most inexpensive manufacturing costs. The most important characteristics of a bus transmission are fatigue life and reliability. If it is overdimensioned it will be too heavy, too large and too expensive. If it is underdimensioned the customer complaints cost will be high and the reputation endangered. Usually city busses run with automatic transmissions to support the driver. Urban or travelling busses usually have a manual transmission. Compared to other vehicles, city busses show a very different driving cycle, mainly dominated by the many acceleration and deceleration phases the bus has. Up to four times per kilometre a city bus has to stop because of bus stops, traffic lights, etc. /WILLMERDING86/. The drive trains of different busses, meaning the arrangement of the engine, transmission and axles vary a lot /BRAUN94/. Therefore many transmission output variants exist for all different busses, the transmission is built into /KÖRNER02/. To develop a reliable transmission housing, the loads and stresses acting on the housing under driving conditions have to be known. While the loads depend on the vehicle characteristics (mass, drive train arrangement, etc.), driver and the route, the stresses depend on the load and the design. The focus of this work is not to develop a relation between load and stress of transmission housing but to figure out dependencies between driving conditions and the fatigue life of transmission housings. There is only limited knowledge about the relation between the driving condi-tions of busses and the damage on the housing. Furthermore it’s unknown how different drive train configurations affect the fatigue life of the housing. The aim of this work is to determine the driving conditions of busses which cause the main damage on the transmission housing. These critical driving conditions are used to develop critical test cycles. Current fatigue life calculation theories do not give accurate absolute fatigue life values for complex parts under multi-axle loads /BUXBAUM83, FKM02B/. But they can be used to determine critical areas and furthermore the results are valid for a relative comparison to see the relative influence of different parameters /FKM02B/. To determine the time-dependent loads, drive-train simulation programs and measured data were used. The behavior of the housing structures was modeled using finite element analyses. The stresses acting on the housings were determined for each relevant single-load case and superimposed for each moment in time. On the one hand a Voith transmission housing was analysed while on the other hand a principal automatic transmission housing was developed and investigated. With local fatigue life concepts the damages of the housings, caused by different routes, were determined. It was found that the damage, resulting from driving-conditions like acceleration and deceleration of the bus, is much higher than the damage caused by engine vibrations or bumps on the road. Furthermore the damage of the housing on a highway trip is much less than on a city trip with the same distance. The number of stops on a trip correlated strongly with the damage caused on the housing. Also the number of shifts correlates with the damage if there are not unusual many shifts in higher gears. A huge fuel consumption was found where a high damage was caused on the housing. The damage on the housing of a full bus is up to two times higher than in an empty bus. The results where used to define characteristic driving conditions for further tests or simulations

Development of dispersion relationships for layered cylinders using laser ultrasonics

M.S.Laurence J. Jacob