1,706 research outputs found

    Fuel economy analysis and powertrain dynamic control of a parallel hydraulic hybrid vehicle

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    University of Technology Sydney. Faculty of Engineering and Information Technology.This research investigates the fuel economy and powertrain vibration characteristics of a parallel hydraulic hybrid vehicle (PHHV). The main work includes: Hydraulic driving system parameter design, energy management strategy (EMS) design, powertrain vibration analysis and transient process control. Firstly, hydraulic driving system parameters are selected based on vehicle power analysis with the Chinese typical urban driving cycle (CTUDC) which is a typical urban driving cycle. PHHV powertrain dynamics are analyzed and components such as engine, hydraulic pump/motor (HPM) and accumulator are modelled to demonstrate the PHHV working principle. PHHV fuel economy is verified by both dynamic programming (DP) optimization and practical rule-based EMS. A lumped parameter dynamic model is built to capture the PHHV powertrain vibration characteristics including the natural frequencies and mode shapes. Then model reduction is conducted to simplify the model complexity while retaining the model fidelity in interested frequency range. The natural frequencies and mode shapes of PHHV powertrain are compared with the original vehicle powertrain which is the vehicle that PHHV refitted from. Results show that the vibration characteristics of PHHV powertrain are not significantly influenced by the addition of hydraulic driving system. Based on the powertrain dynamic model, control strategies are designed for transient process control such as mode switching and power on gear shifting. During mode switching, engine, HPM and engine clutch are coordinately controlled. LQR based closed-loop control strategy is adopted to analyze the effect of engine clutch engaging speed on vehicle jerk, clutch frictional work and hydraulic energy consumption. HPM torque is adjusted to compensate the engine clutch torque to maintain vehicle dynamic performance. To avoid vehicle driving torque interruption during gear shifting, power on gear shifting control strategy is designed. In the control strategy, HPM compensates engine torque when engine clutch is disengaged for gear shifting. Because the available HPM torque depends on its working pressure which varies a lot with different accumulator pressure state, the HPM torque compensation capability is investigated by analyzing the traction force requirement during gear shifting under typical urban driving cycles. With the motivation of taking the advantage of high power density of HPM for in-wheel drive, a novel in-wheel drive electric hydraulic hybrid vehicle (IHV) is proposed as a case study. Its energy economy and vertical vibration characteristics are researched and compared with the centralized motor drive electric vehicle (CEV) and in-wheel drive electric vehicle (IEV)

    Active damping of transient vibration in dual clutch transmission equipped powertrains: A comparison of conventional and hybrid electric vehicles

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    The purpose of this paper is to investigate the active damping of automotive powertrains for the suppression of gear shift related transient vibrations. Conventionally, powertrain vibration is usually suppressed passively through the application of torsional dampers in dual clutch transmissions (DCT) and torque converters in planetary automatic transmissions (AT). This paper presents an approach for active suppression of transient responses utilising only the current sensors available in the powertrain. An active control strategy for manipulating engine or electric machine output torque post gear change via a proportional-integral-derivative (PID) controller is developed and implemented. Whilst conventional internal combustion engine (ICE) powertrains require manipulation of the engine throttle, for HEV powertrains the electric machine (EM) output torque is controlled to rapidly suppress powertrain transients. Simulations for both conventional internal combustion engine and parallel hybrid vehicles are performed to evaluate the proposed strategy. Results show that while both the conventional and hybrid powertrains are both capable of successfully suppressing undesirable transients, the EM is more successful in achieving vibration suppression. © 2014 Elsevier Ltd

    Comparative system dynamic modeling of a conventional and hybrid electric powertrain

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    © 2017 Taylor & Francis Group, London. Hybrid Electric Vehicles (HEVs) provide many known benefits over conventional vehicles, including reduced emissions, increased fuel economy, and performance. The high cost of HEVs has somewhat limited their widespread adoption, especially in developing countries. Conversely, it is these countries that would benefit most from the environmental benefits of HEV technology. As part of our ongoing project to develop a cost-effective and viable mild HEV for these markets, dynamic simulations are required to ensure that the proposed designs are to achieve their desired targets. In this paper, mathematical models of the powertrain are used to analyze and compare the dynamics of both a conventional power train and one with the addition of components required for the Mild Hybrid system. Using Matlab and Simulink, simulations of both powertrains under particular driving conditions are performed to observe the advantages of the MHEV over conventional drivetrains. These benefits include torque-hole filling between gear changes, increased fuel efficiency and performance

    Development and performance evaluation of a prototype electric hybrid powertrain system for automotive applications

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    Researchers at Universiti Teknologi Malaysia (UTM) have developed a dedicated hybrid power plant based on the parallel configuration using a gasoline engine coupled to a high performance electric motor, specifically targeted for automotive application. The aims are to achieve even lower exhaust emissions, better fuel economy and better performance than the conventional arrangement, demonstrating an alternative solution to the conventional power plant. The engine used is a 1.3 litre spark-ignition, coupled with a 27.5 kW Nexus electric motor. The control strategy developed in conjunction with the program is to use the electric drive motor for initial acceleration and for regeneration braking energy recovery, and for reducing the peak load and transients seen by the engine. A relatively small pack of advanced lead acid batteries is use for energy storage. The design, development and evaluation exercises are fully described giving a comprehensive insight of the prototype and its capabilities

    Automatic Control of Clutch Engagement and Slip for Hybrid Vehicle

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    This paper develops a design of an automatic controller of clutch engagement and slip regulation for hybrid electrical vehicle (HEV) using fuzzy logic. The motivation for the use of fuzzy logic control in this study is its ability to handle the system based on uncertain and imprecise input information. Fuzzy logic can reduce the difficulty of mathematical modeling for complex system and can provide a smooth and fast clutch engagement. Fuzzy logic controller can be also used to reduce the vehicle vibration via regulating the slip between two clutch disks. Simulations for the new controller are conducted with Matlab Simulink. Results show that the system can achieve clutch engagement with low jerk and high comfort with considerable vibration reduction

    Fuzzy Logic Control of Clutch for Hybrid Vehicle: Fuzzy Logic Control of Clutch for Hybrid Vehicle

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    This paper provides a design of an automatic clutch controller for hybrid electrical vehicle (HEV) using fuzzy logic. The use of fuzzy logic can reduce the difficulty of mathematical modeling of complex systems since fuzzy logic can deal with uncertain and imprecise data and problems which may have several solutions rather than one. Fuzzy logic algorithms for the automatic clutch controller are developed to achieve a smooth and fast engaging transition. Comprehensive simulations for the whole hybrid electrical vehicle are conducted in Matlab 2009a. An experimental test for a real damping clutch is also carried out. Results show that the active regulation of the clutch slipping ration can considerably reduce the vehicle vibration in resonance frequencies. The new system can handle the clutch engagement with low jerk and high comfort

    A low-cost and novel approach in gearshift control for a mild-hybrid powertrain

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    © 2017 IEEE. A novel, the low-cost mild hybrid powertrain is described. It relies on a manual, or robotized manual transmission together with a BLDC motor coupled at the output for filling the torque hole between gear changes. In order to keep manufacturing cost low and improve commercial attractiveness, it incorporates gearshift strategies that deliver high-quality gear shifts. A deliberate downsizing of componentry is implemented as far as possible to reduce cost, and control strategies are employed to exploit the maximum potential of the architecture using methods including torque-fill, ICE-assist, and ICE start-stop. The architecture is developed in simulation using an existing conventional platform to investigate system properties and their effect on performance. In particular, we discuss the gear-shift control algorithm design. Until the cost of full hybrids and fuel cell vehicles is significantly reduced, such a mild hybrid may have the potential to provide the right cost-benefit balance to achieve strong market penetration

    Torque Allocation of Hybrid Electric Trucks for Drivability and Transient Emissions Reduction

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    This paper aims at investigating powertrain behaviour, especially in transient dynamic responses, using a nonlinear truck vehicle dynamic model with a parallel hybrid configuration. A power split control was designed to achieve the desired drivability performance, with a focus on NOx emissions. The controller was characterized by high-level model-based logic used to elaborate the total powertrain torque required, and a low-level allocation strategy for splitting power between the engine and the electric motor. The final task was to enhance vehicle drivability based on driver requests, with the goal of reducing-in a hybrid configuration-transient diesel engine emissions when compared to a conventional pure thermal engine powertrain. Different parameters were investigated for the assessment of powertrain performance, in terms of external input disturbance rejection and NOx emissions reduction. The investigation of torque allocation performance was limited to the simulation of a Tip-in manoeuvre, which showed a satisfying trade-off between vehicle drivability and transient emissions

    Using a low-cost bluetooth torque sensor for vehicle jerk and transient torque measurement

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    © IMechE 2019. This paper presents the use and development of a specific wireless torque measurement system that is used to obtain the transient torque performance of vehicle transmissions. The torque sensor is strain-based, using surface-mounted strain gauges on a prop shaft. The gauges are connected to a compact printed circuit board, which is clamped to the shaft next to the strain gauges using a three-dimensional printed housing. The printed circuit board contains an amplifier, low-pass filter, analog-to-digital converter, microcontroller and bluetooth transceiver. The printed housing is impact resistant carbon-reinforced nylon and securely retains the printed circuit board and the battery powering the device. The transmitted torque data are received by a transceiver, which is interfaced to a PC through an RS-232 connection. NI LabVIEW is used to process, display and save data. The wireless torque sensor was installed to the Unit Under Test at the output shaft of the five-speed manual transmission. The Unit Under Test was installed on a dynamometer for verification purposes and the transient torque was recorded under various operational conditions. The transient output torque of the manual transmission is measured and compared with results obtained from simulations performed under similar operating conditions. The two sets of transient responses show a good correlation with each other and hence demonstrate that the torque sensor meets the major design specifications. The data obtained will be used to enhance the fidelity of the software model
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