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    A new control strategy for hybrid electric vehicles equipped with a continuously variable transmission

    , Article Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering ; Volume 230, Issue 6 , Aug , 2015 , Pages 803-816 ; 09544070 (ISSN) Delkhosh, M ; Saadat Foumani, M ; Lashgarian Azad, N ; Rostami, P ; Sharif University of Technology
    SAGE Publications Ltd  2015
    Abstract
    The electric assist control strategy is one of the well-known methods for managing the power sources of hybrid electric vehicles. Because of the dependence of the electric assist control strategy approach on its parameters, optimization of this strategy can improve its performance, which results in lower fuel consumption and lower emission levels. However, one of the main concerns about optimization of this strategy is its dependence on the driving behaviour. This paper aims to propose a new control strategy based on the electric assist control strategy with a smaller number of control parameters and less dependence on the driving behaviour. This strategy is usable only for vehicles equipped... 

    Application of multi-speed gearbox in infinitely variable transmission

    , Article Iranian Journal of Science and Technology - Transactions of Mechanical Engineering ; Volume 41, Issue 2 , 2017 , Pages 149-157 ; 22286187 (ISSN) Khadem Nahvi, M ; Delkhosh, M ; Foumani, M. S ; Rostami, P ; Sharif University of Technology
    Shiraz University  2017
    Abstract
    One way to reduce vehicles' fuel consumption (FC) is to optimize different parts of its powertrain. Among different modern powertrains, continuously variable transmission (CVT) is one of the common types which changes speed ratio between engine and wheels, continuously. Therefore, the CVT allows the engine to operate at its fuel-optimal speed. Due to the limited power transmission capacity and speed ratio range of the CVT, researchers attempted to combine the CVT with a planetary gear train and a fixed ratio mechanism. This mechanism is called infinitely variable transmission (IVT). In this study, a multi-speed gearbox (MSG) is used in the IVT and its impact on the powertrain performance and... 

    Geometrical optimization of parallel infinitely variable transmission to decrease vehicle fuel consumption

    , Article Mechanics Based Design of Structures and Machines ; Vol. 42, Issue. 4 , 2014 , Pages 483-501 ; ISSN: 15397734 Delkhosh, M ; Foumani, M. S ; Boroushaki, M ; Sharif University of Technology
    Abstract
    One solution to reduce fuel consumption (FC) of vehicles is to use infinitely variable transmission (IVT) as the power train. However, inappropriate design of IVT leads to an inadequate decrease in the vehicle FC. Therefore, in order to reach a maximum fuel economy, an optimization on the power train proves to be necessary. The present article aims to optimize IVT to decrease the vehicle FC in a driving cycle. The results have revealed that the FC of the vehicle equipped with the optimized IVT is approximately 7% and 4.7% compared to the cases of using the optimized six-speed and nine-speed manual transmissions, respectively  

    Multi-objective geometrical optimization of full toroidal CVT

    , Article International Journal of Automotive Technology ; Volume 14, Issue 5 , 2013 , Pages 707-715 ; 12299138 (ISSN) Delkhosh, M ; Saadat Foumani, M ; Sharif University of Technology
    2013
    Abstract
    The objective of this research is geometrical and kinematical optimization of full-toroidal continuously variable transmission (CVT) in order to achieve high power transmission efficiency and low mass. At first, a dynamic analysis is performed for the system. A computer model is developed to simulate elastohydrodynamic (EHL) contact between disks and roller and consequently, calculate CVT efficiency. The validity of EHL model is investigated by comparing output of this model and experimental data. Geometrical parameters are obtained by means of Particle Swarm Optimization algorithm, while the optimization objective is to maximize CVT efficiency and minimize its mass. The algorithm is run for... 

    A modified control strategy for parallel hybrid electric vehicles equipped with continuously variable transmission

    , Article Scientia Iranica ; Volume 23, Issue 3 , 2016 , Pages 966-975 ; 10263098 (ISSN) Delkhosh, M ; Foumani, M. S ; Falahati, F ; Sharif University of Technology
    Sharif University of Technology  2016
    Abstract
    This paper aims to establish a control strategy for parallel hybrid electric vehicles equipped with full-toroidal Continuously Variable Transmission (CVT). First, the advantages of CVT are elucidated. Afterwards, a modified control strategy on the base of Baseline static Control Strategy (BCS) is proposed. Employing this strategy, in some moments, the engine operates in its fuel-optimal point to decrease the vehicle Fuel Consumption (FC). It is demonstrated that the modifications in BCS are applicable using a CVT as the power train. In order to investigate the implemented modification, an optimization on the proposed control strategy and BCS in SC03 driving cycle is accomplished and then,... 

    Improving the Control Strategy of Hybrid Electric Vehicle Equipped with
    Continuously Variable Transmission

    , Ph.D. Dissertation Sharif University of Technology Delkhosh, Mojtaba (Author) ; Saadat Foumani, Mahmoud (Supervisor) ; Nasser, Lashgarian Azad (Co-Advisor)
    Abstract
    Hybridization of the vehicles is one of the main solutions for reducing the vehicles’ fuel consumption (FC) and emissions. Hybrid electric vehicles (HEVs) are one of the main groups of hybrid vehicles. In this type, an electric motor is employed to help the engine propel the vehicle. Other method which can be implemented to reduce the vehicle’s FC and emissions is to employ continuously variable transmission (CVT) as the vehicle power transmission. By using CVT, the engine will be able to operate in the rotational speed approximately independent of the vehicle speed, which leads to a reduction in the engine’ FC and emissions. One of the main concerns in the HEVs’ design is the layout of its... 

    Optimisation of full-toroidal continuously variable transmission in conjunction with fixed ratio mechanism using particle swarm optimisation

    , Article Vehicle System Dynamics ; Volume 51, Issue 5 , Feb , 2013 , Pages 671-683 ; 00423114 (ISSN) Delkhosh, M ; Foumani, M. S ; Sharif University of Technology
    2013
    Abstract
    The aim of this research is the optimisation of full-toroidal continuously variable transmission (CVT) in conjunction with the fixed ratio (FR) mechanism, while the optimisation objective is to minimise fuel consumption (FC) of the vehicle in the new European driving cycle. After the dynamic analysis of the power train, a computer model is developed to simulate contact between CVT elements and consequently calculate its efficiency. Then an algorithm is presented to calculate FC of the vehicle in the driving cycle. Then, an optimisation using particle swarm optimisation on the CVT geometry and FR mechanism (which is embedded between CVT and final drive) is carried out to minimise FC. It is... 

    Geometrical optimization of half toroidal continuously variable transmission using particle swarm optimization

    , Article Scientia Iranica ; Volume 18, Issue 5 , 2011 , Pages 1126-1132 ; 10263098 (ISSN) Delkhosh, M ; Saadat Foumani, M ; Boroushaki, M ; Ekhtiari, M ; Dehghani, M ; Sharif University of Technology
    Abstract
    The objective of this research is geometrical optimization of half toroidal Continuously Variable Transmission (CVT) in order to achieve high power transmission efficiency. The dynamic analysis of CVT is implemented and contact between the disk and the roller is modeled viaelastohydrodynamic (EHL) lubrication principles. Computer model is created using geometrical, thermal and kinetic parameters to determine the efficiency of CVT. Results are compared by other models to confirm the model validity. Geometrical parameters are obtained by means of Particle Swarm Optimization (PSO) algorithm, while the optimization objective is to maximize the power transmission efficiency. Optimization was... 

    Investigating the effect of engine noise on power management strategy of a hybrid electric vehicle

    , Article Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering ; Volume 232, Issue 10 , 2018 , Pages 1287-1296 ; 09544070 (ISSN) Delkhosh, M ; Aliramezani, M ; Khadem Nahvi, M ; Sharif University of Technology
    SAGE Publications Ltd  2018
    Abstract
    Hybrid electric vehicles (HEVs) have been developed as a promising way to decrease the fuel consumption and emissions of conventional vehicles. Although the noise emission of HEVs is generally lower than that of conventional vehicles, it is still an issue, especially in urban transportation. In this paper, a power management strategy is developed to minimize the annoying noise of the engine for an HEV. This is a modified version of the strategy that was originally established based on the speed ratio of continuously variable transmission (CVT) as the control parameter (CVT-based strategy). The engine combustion noise is assessed using the experimental data of the in-cylinder pressure. Also,... 

    Optimization of multiple transmission layouts for minimal energy consumption of a battery electric vehicle

    , Article Scientia Iranica ; Volume 26, Issue 4A , 2019 , Pages 2382-2393 ; 10263098 (ISSN) Farjam, T ; Foumani, M. S ; Delkhosh, M ; Sharif University of Technology
    Sharif University of Technology  2019
    Abstract
    Battery Electric Vehicles (BEVs) are a promising solution for reducing the impacts of passenger vehicles on the environment. However, their driving range is restricted due to the limitations of battery technologies. This range can be extended by adoption of multiple-speed transmissions. Most of the comparisons in the related studies are based on non-optimal designs or limited to modal driving cycles. Furthermore, the impact of Power-Split. Continuously Variable Transmission (PS-CVT) layout with type III power How on the power consumption of BEVs has never been examined. In this paper, single-, two-, and three-speed transmissions along with PS-C'VTs with type I and III power flows are... 

    Optimization of multiple transmission layouts for minimal energy consumption of a battery electric vehicle

    , Article Scientia Iranica ; Volume 26, Issue 4A , 2019 , Pages 2382-2393 ; 10263098 (ISSN) Farjam, T ; Saadat Foumani , M ; Delkhosh, M ; Sharif University of Technology
    Sharif University of Technology  2019
    Abstract
    Battery Electric Vehicles (BEVs) are a promising solution for reducing the impacts of passenger vehicles on the environment. However, their driving range is restricted due to the limitations of battery technologies. This range can be extended by adoption of multiple-speed transmissions. Most of the comparisons in the related studies are based on non-optimal designs or limited to modal driving cycles. Furthermore, the impact of Power-Split. Continuously Variable Transmission (PS-CVT) layout with type III power How on the power consumption of BEVs has never been examined. In this paper, single-, two-, and three-speed transmissions along with PS-C'VTs with type I and III power flows are...