The Experts below are selected from a list of 78783 Experts worldwide ranked by ideXlab platform
Stefano Bertolotto - One of the best experts on this subject based on the ideXlab platform.
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Optimization of a Multiple-Speed Transmission for Downsizing the Motor of a Fully Electric Vehicle
SAE International Journal of Alternative Powertrains, 2012Co-Authors: Francesca Di Nicola, Aldo Sorniotti, Thomas Holdstock, Fabio Viotto, Stefano BertolottoAbstract:The research presented in this paper focuses on the effects of downsizing the electric motor drive of a fully electric vehicle through the adoption of a multiple-Speed Transmission system. The activity is based on the implementation of a simulation framework in Matlab / Simulink. The paper considers a rear wheel drive case study vehicle, with a baseline drivetrain configuration consisting of a single-Speed Transmission, which is compared with drivetrains adopting motors with identical peak power but higher base Speeds and lower peak torques coupled with multiple-Speed Transmissions (double and three-Speed), to analyze the benefits in terms of energy efficiency and performance. The gear ratios and gearshift maps for each multiple-Speed case study are optimized through a procedure developed by the authors consisting of cost functions considering energy efficiency and performance evaluation. The cost functions are explained in the paper along with the models adopted for the research. Copyright © 2012 SAE International.
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analysis and simulation of the gearshift methodology for a novel two Speed Transmission system for electric powertrains with a central motor
Proceedings of the Institution of Mechanical Engineers Part D: Journal of Automobile Engineering, 2012Co-Authors: Aldo Sorniotti, Thomas Holdstock, Gabriele Loro Pilone, Fabio Viotto, Stefano Bertolotto, Mike Everitt, Robert J Barnes, Ben Stubbs, Matt WestbyAbstract:Electric vehicle powertrains traditionally consist of a central electric motor drive, a single-Speed Transmission and a differential. This electric powertrain layout, for use in either fully electr...
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Energy consumption analysis of a novel four-Speed dual motor drivetrain for electric vehicles
2012 IEEE Vehicle Power and Propulsion Conference, 2012Co-Authors: Thomas Holdstock, Aldo Sorniotti, M. Everitt, M. Fracchia, S. Bologna, Stefano BertolottoAbstract:The electric vehicle is becoming increasingly prevalent as a viable option to replace hydrocarbon fuelled vehicles, and as such the development of high efficiency fully electric drivetrains is a particularly relevant research topic. The drivetrain topology is one of the main focuses of research on fully electric drivetrains, because of the variety of available options. For example, the adoption of multiple-Speed mechanical Transmissions can improve both the performance and energy consumption when compared to a single-Speed Transmission. A four-Speed, dual motor drivetrain design is presented in this article which works on the principle of two double-Speed Transmissions, each driven by a separate motor linked through a sole secondary shaft. This drivetrain architecture provides increased flexibility of the electric motor operating points, theoretically being beneficial to the overall efficiency of the system for any driving condition. This paper presents the design of the Transmission, its governing equations and the method adopted to optimize the state selection map and electric motor torque distribution. A backward-facing energy consumption model is used to compare the results of the four-Speed Transmission with those of single- and double-Speed Transmissions for four case study vehicles.
D Celo - One of the best experts on this subject based on the ideXlab platform.
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passive parameterized time domain macromodels for high Speed Transmission line networks
IEEE Transactions on Microwave Theory and Techniques, 2003Co-Authors: P Gunupudi, Roni Khazaka, M Nakhla, T Smy, D CeloAbstract:There is a significant need for efficient and accurate macromodels of components during the design of microwave circuits. Increased integration levels in microwave devices and higher signal Speeds have produced the need to include effects previously neglected during circuit simulations. Accurate prediction of these effects involve solution of large systems of equations, the direct simulation of which is prohibitively CPU expensive. In this paper, an algorithm is proposed to form passive parametrized macromodels of large linear networks that match the characteristics of the original network in time, as well as other design parameters of the circuit. A novel feature of the algorithm is the ability to incorporate a set of design parameters within the reduced model. The size of the reduced models obtained using the proposed algorithm were less than 5% when compared to the original circuit. A Speedup of an order of magnitude was observed for typical high-Speed Transmission-line networks. The algorithm is general and can be applied to other disciplines such as thermal analysis.
P Gunupudi - One of the best experts on this subject based on the ideXlab platform.
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recursive multi parameter closed form expressions for high Speed Transmission line networks
Electrical Performance of Electronic Packaging, 2006Co-Authors: N Rodrigues, A Jerome, P GunupudiAbstract:In this paper, an efficient algorithm to extract multi-parameter closed-form expressions for the response of Transmission line circuits is proposed. The proposed algorithm was applied to simulate practical Transmission line networks and a significant Speed-up was obtained.
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passive parameterized time domain macromodels for high Speed Transmission line networks
IEEE Transactions on Microwave Theory and Techniques, 2003Co-Authors: P Gunupudi, Roni Khazaka, M Nakhla, T Smy, D CeloAbstract:There is a significant need for efficient and accurate macromodels of components during the design of microwave circuits. Increased integration levels in microwave devices and higher signal Speeds have produced the need to include effects previously neglected during circuit simulations. Accurate prediction of these effects involve solution of large systems of equations, the direct simulation of which is prohibitively CPU expensive. In this paper, an algorithm is proposed to form passive parametrized macromodels of large linear networks that match the characteristics of the original network in time, as well as other design parameters of the circuit. A novel feature of the algorithm is the ability to incorporate a set of design parameters within the reduced model. The size of the reduced models obtained using the proposed algorithm were less than 5% when compared to the original circuit. A Speedup of an order of magnitude was observed for typical high-Speed Transmission-line networks. The algorithm is general and can be applied to other disciplines such as thermal analysis.
Erwan Pincemin - One of the best experts on this subject based on the ideXlab platform.
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All-optical wavelength conversion by EAM with shifted bandpass filter for high bit-rate networks
IEEE Photonics Technology Letters, 2006Co-Authors: Nagib Dahdah, R. Coquill??, Benoit Charbonnier, Armand Vedadi, Guy Aubin, Erwan Pincemin, Jean Decobert, Christophe Kazmierski, Abderrahim RamdaneAbstract:We report an original optical wavelength converter for transparent network and high-Speed Transmission. Based on an electroabsorption modulator (EAM) in cross-absorption modulation configuration, a red-shifted center wavelength filtering of the converted signal decreases the impact of the limited EAM response time. This original and simple device demonstrates wavelength conversion at 40 Gb/s, leading to a reduction of 4.7 dB on the bit-error rate (BER) penalty compared to the case of a centered filter. An absolute 1.8-dB BER power penalty, low switching energy (500 fJ/data pulse) and small applied DC bias are reported.
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optimal span length in high Speed Transmission systems with hybrid raman erbium doped fiber amplification
Optics Letters, 2005Co-Authors: Juan Diego Aniacastanon, Irina O Nasieva, Sergei K Turitsyn, Nicolas Brochier, Erwan PinceminAbstract:We show, using nonlinearity management, that the optimal performance in high-bit-rate dispersion-managed fiber systems with hybrid amplification is achieved for a specific amplifier spacing that is different from the asymptotically vanishing length corresponding to ideally distributed amplification [Opt. Lett. 15, 1064 (1990)]. In particular, we prove the existence of a nontrivial optimal span length for 40-Gbit/s wavelength-division Transmission systems with Raman-erbium-doped fiber amplification. Optimal amplifier lengths are obtained for several dispersion maps based on commonly used Transmission fibers. © 2005 Optical Society of America.
S Tachikawa - One of the best experts on this subject based on the ideXlab platform.
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performance evaluation of received response code sequence ds uwb system in comparison with mbok ds uwb system
Asia-Pacific Conference on Communications, 2008Co-Authors: K B Toh, S TachikawaAbstract:This paper proposes a novel received response (RR) code sequence as the spread code for the direct sequence-ultra wideband (DS-UWB) multipath channel model. This paper also demonstrates the effectiveness of the RR code sequence in inter-symbol interference (ISI) reduction for the DS-UWB system. It suggests that by using conventional M-ary biorthogonal keying based direct sequence-ultra wideband (MBOK DS-UWB) system, there is a possibility of generating extra ISI in the UWB system. Therefore, it is quite difficult to collect the energy efficiently although the RAKE reception method is applied at the receiver. The main feature of the proposed RR code sequence is to reduce the ISI effect during high Speed Transmission of ultra short pulses in a multipath channel. Simulation results verify that significant improvement can be obtained by the proposed system in the UWB multipath channel models compared to the MBOK DS-UWB system.
