1,391 research outputs found
Online Control of Automotive systems for improved Real-World Performance
[ES] La necesidad de mejorar el consumo de combustible y las emisiones de los sistemas propulsivos de automoción en condiciones reales de
conducción es la base de esta tesis. Para ello, se exploran dos ejes: En primer
lugar, el control de los sistemas de propulsión. El estado del arte de control en
los sistemas propulsivos de automoción se basa en gran medida en el uso de
técnicas de optimización que buscan las leyes de control que minimizan una
función de coste en un conjunto de condiciones de operación denidas a priori.
Estas leyes se almacenan en las ECUs de producción en forma de mapas de
calibración de los diferentes actuadores del motor. Las incertidumbres asociadas al conjunto limitado de condiciones en el proceso de calibración dan lugar
a un funcionamiento subóptimo del sistema de propulsión en condiciones de
conducción real. Por lo tanto, en este trabajo se proponen métodos de control
adaptativo que optimicen la gestión de la planta propulsiva a las condiciones
esperadas de funcionamiento para un usuario y un caso determinado en lugar de a un conjunto genérico de condiciones. El segundo eje se reere a
optimizar, en lugar de los parámetros de control del sistema propulsivo, la
demanda de potencia de este, introduciendo al propio conductor en el bucle
de control, sugiriéndole las acciones a tomar. En particular, este segundo
eje se reere al control de la velocidad del vehículo (conocido popularmente
como Eco-Driving en la literatura) en condiciones reales de conducción. Se
proponen sistemas de aviso en tiempo real al conductor acerca de la velocidad óptima para minimizar el consumo del vehículo. Los métodos de control
desarrollados para cada aplicación se describen en detalle en la tesis y se muestran ensayos experimentales de validación en los casos de estudio diseñados.
Ambos ejes representan un problema de control óptimo, denido por un sistema dinámico, unas restricciones a cumplir y un coste a minimizar, en este
sentido las herramientas desarrolladas en la tesis son comunes a los dos ejes:
Un modelo de vehículo, una herramienta de predicción del ciclo de conducción
y métodos de control óptimo (Programación Dinámica, Principio Mínimo de
Pontryagin y Estrategia de Consumo Equivalente Mínimo). Dependiendo de
la aplicación, los métodos desarrollados se implementaron en varios entornos
experimentales: un motor térmico en sala de ensayos simulando el resto del
vehículo, incluyendo el resto del sistema de propulsión híbrido y en un vehículo real. Los resultados muestran mejoras signicativas en el rendimiento
del sistema de propulsión en términos de ahorro de combustible y emisiones
en comparación con los métodos empleados en el estado del arte actual.[CA] La necessitat de millorar el consum de combustible i les emissions
dels sistemes propulsius d'automoció en condicions reals de conducció és la
base d'aquesta tesi. Per a això, s'exploren dos eixos: En primer lloc, el control
dels sistemes de propulsió. L'estat de l'art de control en els sistemes propulsius
d'automoció es basa en gran manera en l'ús de tècniques d'optimització que
busquen les lleis de control que minimitzen una funció de cost en un conjunt
de condicions d'operació denides a priori. Aquestes lleis s'emmagatzemen
en les Ecus de producció en forma de mapes de calibratge dels diferents actuadors del motor. Les incerteses associades al conjunt limitat de condicions
en el procés de calibratge donen lloc a un funcionament subòptim del sistema
de propulsió en condicions de conducció real. Per tant, en aquest treball es
proposen mètodes de control adaptatiu que optimitzen la gestió de la planta
propulsiva a les condicions esperades de funcionament per a un usuari i un
cas determinat en lloc d'un conjunt genèric de condicions. El segon eix es
refereix a optimitzar, en lloc dels paràmetres de control del sistema propulsiu,
la demanda de potència d'aquest, introduint al propi conductor en el bucle
de control, suggerint-li les accions a prendre. En particular, aquest segon eix
es refereix al control de la velocitat del vehicle (conegut popularment com
Eco-*Driving en la literatura) en condicions reals de conducció. Es proposen
sistemes d'avís en temps real al conductor sobre la velocitat òptima per a
minimitzar el consum del vehicle. Els mètodes de control desenvolupats per
a cada aplicació es descriuen detalladament en la tesi i es mostren assajos
experimentals de validació en els casos d'estudi dissenyats. Tots dos eixos
representen un problema de control òptim, denit per un sistema dinàmic,
unes restriccions a complir i un cost a minimitzar, en aquest sentit les eines
desenvolupades en la tesi són comunes als dos eixos: Un model de vehicle,
una eina de predicció del cicle de conducció i mètodes de control òptim (Programació Dinàmica, Principi Mínim de *Pontryagin i Estratègia de Consum
Equivalent Mínim). Depenent de l'aplicació, els mètodes desenvolupats es
van implementar en diversos entorns experimentals: un motor tèrmic en sala
d'assajos simulant la resta del vehicle, incloent la resta del sistema de propulsió híbrid i en un vehicle real. Els resultats mostren millores signicatives
en el rendiment del sistema de propulsió en termes d'estalvi de combustible i
emissions en comparació amb els mètodes emprats en l'estat de l'art actual.[EN] The need of improving the real-world fuel consumption and emission of automotive applications is the basis of this thesis. To this end, two
verticals are explored: First is the online control of the powertrain systems. In
state-of-the-art Optimal Control techniques (such as Dyanmic Programming,
Pontryagins Minimum Principle, etc...) are extensively used to formulate the
optimal control laws. These laws are stored in the production ECUs in the
form of feedforward calibration maps. The unaccounted uncertainities related to the real-world during the powertrain calibration result in suboptimal
operations of the powertrain in actual driving. Therefore, adaptive control
methods are proposed in this work which, optimise the energy management
of the conventional and the HEV powertrain control on real driving mission.
The second vertical is regarding the vehicle speed control (popularly known as
Eco-Driving in the literature) methods in real driving condition. In particular,
speed advisory systems are proposed for real time application on a vehicle.
The control methods developed for each application are described in details
with their verication and validation on the designed case studies. Apart from
the developed control methods, there are three tools that were developed and
used at various stages of this thesis: A vehicle model, A driving cycle prediction tool and optimal control methods (dynamic programming, PMP and
ECMS). Depending on the application, the developed methods were implemented on the Hardware-In-Loop Internal Combustion Engine testing setup
or on a real vehicle. The results show signicant improvements in the performance of the powertrain in terms of fuel economy and emissions in comparison
to the state-of-the-art methods.Pandey, V. (2021). Online Control of Automotive systems for improved Real-World Performance [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/173716TESI
Primary fallopian tube cancer in the setting of endometriosis
We report the first case of PFTC arising in the setting of pelvic endometriosis. A 45 year old nulliparous lady, menopausal lady presented with pelvic mass. She had history of pelvic endometriosis. MRI findings were suggestive of ovarian malignancy. Histological analysis of specimen obtained following staging laparotomy proved it to be a case of bilateral PFTC. She received 6 cycles of adjuvant chemotherapy. This case opens a new door to think or investigate if fallopian tube endometrioma behaves as a more aggressive premalignant lesion. This case also poses questions whether it is important to differentiate an endometrioma arising from the ovary to one which is arising from a fallopian tube. Once identified can fallopian tube endometrioma also be managed medically or should it be always removed surgically
Application of Size and Shape Dependent Model for ShearModulus of Nanomaterials
A simple theory based on bond energy model is developed. The model is used to predict the size and shape dependenceof shear modulus of different nanomaterials. The results obtained are compared with the our theoretical predictions as wellas experimental data. In small size range (<10nm) there is a very good agreement between earlier predictions as well asexperimental observations. It is discussed that present model is very simple as compared with the earlier model. In additionto this, our model includes the effect of shape also, which has not been considered in earlier theory. Due to the simplicityand applicability of the model, it can be used to understand the size and shape dependence of shear modulus ofnanomaterials. To the best of our knowledge, such simple model is not yet available in the literature to predict the size andshape dependence of shear modulu
Impact of driving dynamics in RDE test on NOx emissions dispersion
[EN] EU6D emission regulation intends to bridge the gap between laboratory tests and the real driving conditions by introducing real drive emission testing. It requires the measurement of real drive emission to be an additional type approval test in order to take into account the influence of road profile, ambient conditions and traffic situations. An important amendment has been included in Commission regulation (European Union) 2016/646, limiting the driving dynamics and hence avoiding the biased testing of the vehicle. In this work, a drive cycle generator has been developed to synthesise cycles meeting all the regulatory requirements of the real drive emission testing. The generator is based on the transition probability matrix obtained from each phase of the World harmonised Light vehicle Test Procedure cycle. Driving dynamics have been varied based on real drive emission regulations, and several trips have been generated with dynamics ranging from soft to aggressive. A direct injection compression ignition 1.5 L engine with a state-of-the-art aftertreatment system has been utilised to run the generated synthetic cycles. The analysis of the results obtained in the tests (all of them complying with real drive emission restrictions in terms of driving dynamics) points out a noticeable 60% relative dispersion in the NO(x)emissions downstream of the catalyst. The contribution of the proposed method lies not only in the fact that it synthesises driving cycles as stochastic process and is capable of tuning the driving dynamics based on real drive emission regulations, but it also presents the range of dispersion possible in NO (x)emissions solely due to the driving dynamics. The methodology followed in the present work could be an essential step in future engine developments, where testing engine prototypes on the entire range of driving dynamics in the engine test bench facility could provide interesting insights about the expected NO(x)emissions in real drive emission testing.The authors acknowledge the support of Spanish Ministrrio de Economia, Industria y Competitivad through project TRA2016-78717-RLuján, JM.; Guardiola, C.; Pla Moreno, B.; Pandey, V. (2020). Impact of driving dynamics in RDE test on NOx emissions dispersion. Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering. 234(6):1770-1778. https://doi.org/10.1177/0954407019881581S177017782346Hooftman, N., Messagie, M., Van Mierlo, J., & Coosemans, T. (2018). A review of the European passenger car regulations – Real driving emissions vs local air quality. Renewable and Sustainable Energy Reviews, 86, 1-21. doi:10.1016/j.rser.2018.01.012Chen, Y., & Borken-Kleefeld, J. (2014). Real-driving emissions from cars and light commercial vehicles – Results from 13 years remote sensing at Zurich/CH. Atmospheric Environment, 88, 157-164. doi:10.1016/j.atmosenv.2014.01.040Veerle H, Gerrit K, Norbert L, et al. NOx emissions of fifteen euro 6 diesel cars: results of the Dutch LD road vehicle emission testing programme 2016. Technical Report, TNO, Delft, 10 October 2016.Samuel, S., Morrey, D., Fowkes, M., Taylor, D. H. C., Austin, L., Felstead, T., & Latham, S. (2005). Real-world fuel economy and emission levels of a typical EURO-IV passenger vehicle. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 219(6), 833-842. doi:10.1243/095440705x28277Zacharof, N., Tietge, U., Franco, V., & Mock, P. (2016). Type approval and real-world CO2 and NOx emissions from EU light commercial vehicles. Energy Policy, 97, 540-548. doi:10.1016/j.enpol.2016.08.002Luján, J. M., Climent, H., Ruiz, S., & Moratal, A. (2018). Influence of ambient temperature on diesel engine raw pollutants and fuel consumption in different driving cycles. International Journal of Engine Research, 20(8-9), 877-888. doi:10.1177/1468087418792353Lin, J., & Niemeier, D. A. (2002). An exploratory analysis comparing a stochastic driving cycle to California’s regulatory cycle. Atmospheric Environment, 36(38), 5759-5770. doi:10.1016/s1352-2310(02)00695-7Lee, T. K., & Filipi, Z. S. (2011). Synthesis of real-world driving cycles using stochastic process and statistical methodology. International Journal of Vehicle Design, 57(1), 17. doi:10.1504/ijvd.2011.043590Gong, Q., Midlam-Mohler, S., Marano, V., & Rizzoni, G. (2011). An Iterative Markov Chain Approach for Generating Vehicle Driving Cycles. SAE International Journal of Engines, 4(1), 1035-1045. doi:10.4271/2011-01-0880Miller J, Franco V. Impact of improved regulation of real-world NOx emissions from diesel passenger cars in the EU 2015 2030. Technical Report, International Council on Clean Transportation, Washington DC, December 2016.Rajan, B., McGordon, A., & Jennings, P. (2012). An Investigation on the Effect of Driver Style and Driving Events on Energy Demand of a PHEV. World Electric Vehicle Journal, 5(1), 173-181. doi:10.3390/wevj5010173Gallus, J., Kirchner, U., Vogt, R., & Benter, T. (2017). Impact of driving style and road grade on gaseous exhaust emissions of passenger vehicles measured by a Portable Emission Measurement System (PEMS). Transportation Research Part D: Transport and Environment, 52, 215-226. doi:10.1016/j.trd.2017.03.011Van Mierlo, J., Maggetto, G., Van de Burgwal, E., & Gense, R. (2004). Driving style and traffic measures-influence on vehicle emissions and fuel consumption. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 218(1), 43-50. doi:10.1243/095440704322829155Ericsson, E. (2001). Independent driving pattern factors and their influence on fuel-use and exhaust emission factors. Transportation Research Part D: Transport and Environment, 6(5), 325-345. doi:10.1016/s1361-9209(01)00003-7Guardiola, C., Pla, B., Bares, P., & Waschl, H. (2016). Adaptive calibration for reduced fuel consumption and emissions. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 230(14), 2002-2014. doi:10.1177/095440701663697
Adaptive calibration of Diesel engine injection for minimising fuel consumption with constrained NOx emissions in actual driving missions
This is the author¿s version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting,
and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087420918800[EN] This article proposes a method for fuel minimisation of a Diesel engine with constrained NOx emission in actual driving mission. Specifically, the methodology involves three developments: The first is a driving cycle prediction tool which is based on the space-variant transition probability matrix obtained from an actual vehicle speed dataset. Then, a vehicle and an engine model is developed to predict the engine performance depending on the calibration for the estimated driving cycle. Finally, a controller is proposed which adapts the start-of-injection calibration map to fulfil the NOx emission constraint while minimising the fuel consumption. The calibration is adapted during a predefined time window based on the predicted engine performance on the estimated cycle and the difference between the actual and the constraint on engine NOx emissions. The method assessment was done experimentally in the engine test set-up. The engine performace using the method is compared with the state-of-the-art static calibration method for different NOx emission limits on real driving cycles. The online implementation of the method shows that the fuel consumption can be reduced by 3%-4% while staying within the emission limits, indicating that the estimation method is able to capture the main driving cycle characterstics.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors acknowledge the support of Spanish Ministrrio de Economia, Industria y Competitivad through project TRA2016-78717-R.Luján, JM.; Pla Moreno, B.; Bares-Moreno, P.; Pandey, V. (2021). Adaptive calibration of Diesel engine injection for minimising fuel consumption with constrained NOx emissions in actual driving missions. International Journal of Engine Research. 22(6):1896-1905. https://doi.org/10.1177/1468087420918800S1896190522
Ultrafast Field-Resolved Nonlinear Optical Spectroscopy in the Molecular Frame
We resolve the real-time electric field of a femtosecond third-order
nonlinear optical signal in the molecular frame. The electric field emitted by
the induced third-order polarization from impulsively pre-aligned gas-phase
molecules at room temperature, in a degenerate four-wave mixing (DFWM) scheme,
is measured using a spectral interferometry technique. We show that by
measuring both the amplitude and phase of the emitted femtosecond pulse,
information related to electronic symmetries can be accessed. The nonlinear
signal is measured around a rotational revival to extract its molecular-frame
angle dependence from pump-probe time delay scans. By comparing these
measurements for two linear molecules, carbon dioxide (CO2) and Nitrogen (N2),
we show that the measured second-order phase parameter (temporal chirp) of the
signal is sensitive to the valence electronic symmetry of the molecules,
whereas the amplitude of the signal does not show such sensitivity. We compare
these measurements to theoretical calculations of the chirp observable in the
molecular frame. This work is an important step towards using field-resolved
nonlinear optical measurements to study ultrafast dynamics in electronically
excited molecules.Comment: 10 pages, 3 figures and 1 supplemental documen
Realization of OFCC based transimpedance mode instrumentation amplifier
The paper presents an instrumentation amplifier suitable for amplifying the current source transducer signals. It provides a voltage output. It has a high gain, common mode rejection ratio and gain independent bandwidth. It uses three Operational Floating Current Conveyors (OFCCs) and four resistors. The effect of nonidealities of OFCC on performance of proposed transimpedance instrumentation amplifier (TIA) is also analyzed. The proposal has been verified through SPICE simulations using CMOS based schematicThe paper presents an instrumentation amplifier suitable for amplifying the current source transducer signals. It provides a voltage output. It has a high gain, common mode rejection ratio and gain independent bandwidth. It uses three operational floating current conveyors (OFCCs) and four resistors. The effect of nonidealities of OFCC on performance of proposed transimpedance instrumentation amplifier (TIA) is also analyzed. The proposal has been verified through SPICE simulations using CMOS based schematic
VMD: a community annotation database for oomycetes and microbial genomes
The VBI Microbial Database (VMD) is a database system designed to host a range of microbial genome sequences. At present, the database contains genome sequence and annotation data of two plant pathogens Phytophthora sojae and Phytophthora ramorum. With the completion of the draft genome sequences of these pathogens in collaboration with the DOE Joint Genome Institute (JGI), we have created this resource to make the sequences publicly available. The genome sequences (95 MB for P.sojae and 65 MB for P.ramorum) were annotated with ∼19 000 and ∼16 000 gene models, respectively. We used two different statistical methods to validate these gene models, Fickett's and a log-likelihood method. Functional annotation of the gene models is based on results from BlastX and InterProScan screens. From the InterProScan results, we could assign putative functions to 17 694 genes in P.sojae and 14 700 genes in P.ramorum. We created an easy-to-use genome browser to view the genome sequence data, which opens to detailed annotation pages for each gene model. A community annotation interface is available for registered community members to add or edit annotations. There are ∼ 1600 gene models for P.sojae and ∼700 models for P.ramorum that have already been manually curated. A toolkit is provided as an additional resource for users to perform a variety of sequence analysis jobs. The database is publicly available at
Variable smoothing of optimal diesel engine calibration for improved performance and drivability during transient operation
[EN] The model-based method to define the optimal calibration maps for important diesel engine parameters may involve three major steps. First, the engine speed and load domain - in which the engine is operated - are identified. Then, a global engine model is created, which can be used for offline simulations to estimate engine performance. Finally, optimal calibration maps are obtained by formulating and solving an optimisation problem, with the goal of minimising fuel consumption while meeting constraints on pollutant emissions. This last step in the calibration process usually involves smoothing of the maps in order to improve drivability. This article presents a method to trade off map smoothness, brake-specific fuel consumption and nitrogen oxide emissions. After calculating the optimal but potentially non-smooth calibration maps, a variation-based smoothing method is employed to obtain different levels of smoothness by adapting a single tuning parameter. The method was experimentally validated on a heavy-duty diesel engine, and the non-road transient cycle was used as a case study. The error between the reference and actual engine torque was used as a metric for drivability, and the error was found to decrease with increasing map smoothness. After having obtained this trade-off for various fixed levels of smoothness, a time-varying smoothness calibration was generated and tested. Experimental results showed that, with a time-varying smoothness strategy, nitrogen oxide emissions could be reduced by 4%, while achieving the same drivability and fuel consumption as in the case of a fixed smoothing strategy.The authors acknowledge the support of Spanish Ministerio de Economia, Industria y Competitividad through project TRA2016-78717-R, and this work was developed during the research stay of Varun Pandey at the ETH funded by the Programa de Movilidad para la Formacion de Personal Investigador del Vicerrectorado de Investigacion, Innovacion y Transferencia de la UPV.Pandey, V.; Van Dooren, S.; Ritzmann, J.; Pla Moreno, B.; Onder, C. (2021). Variable smoothing of optimal diesel engine calibration for improved performance and drivability during transient operation. International Journal of Engine Research. 22(6):1888-1895. https://doi.org/10.1177/1468087420918801S1888189522
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