6,945 research outputs found

    Phase 1 of the near term hybrid passenger vehicle development program

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    In order to meet project requirements and be competitive in the 1985 market, the proposed six-passenger vehicle incorporates a high power type Ni-Zn battery, which by making electric-only traction possible, permits the achievement of an optimized control strategy based on electric-only traction to a set battery depth of discharge, followed by hybrid operation with thermal primary energy. This results in a highly efficient hybrid propulsion subsystem. Technical solutions are available to contain energy waste by reducing vehicle weight, rolling resistance, and drag coefficient. Reproaching new 1985 full size vehicles of the conventional type with hybrids of the proposed type would result in a U.S. average gasoline saving per vehicle of 1,261 liters/year and an average energy saving per vehicle of 27,133 MJ/year

    Next Generation HEV Powertrain Design Tools: Roadmap and Challenges

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    Hybrid electric vehicles (HEVs) represent a fundamental step in the global evolution towards transportation electrification. Nevertheless, they exhibit a remarkably complex design environment with respect to both traditional internal combustion engine vehicles and battery electric vehicles. Innovative and advanced design tools are therefore crucially required to effectively handle the increased complexity of HEV development processes. This paper aims at providing a comprehensive overview of past and current advancements in HEV powertrain design methodologies. Subsequently, major simplifications and limits of current HEV design methodologies are detailed. The final part of this paper defines research challenges that need accomplishment to develop the next generation HEV architecture design tools. These particularly include the application of multi-fidelity modeling approaches, the embedded design of powertrain architecture and on-board control logic and the endorsement of multi-disciplinary optimization procedures. Resolving these issues may indeed remarkably foster the widespread adoption of HEVs in the global vehicle market

    Bus manufacturing: line balancing and optimization

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    Bus production is a singular industry due to the product variety and customization usually required by clients. Buses are usually conceived based in a chassis where a frame is built, following the safety rules adopted by the sector. The external view can be similar, but some construction aspects and internal view are usually defined by the client, leading to a high customization. Thus, the bus can be manufactured in a common line, but the different configurations usually lead to a complex assembling process that needs to be carefully thought. Moreover, this kind of industry is permanently subjected to huge competitiveness and sustainable evaluation, which implies a rigorous cost planning and production, avoiding budget problems. This work was carried out in a bus manufacturer located in the Porto surroundings, which produces a large number of bus types for airports, tourism, urban or scholar purposes. The factory has three different production lines, being each one allocated to a different kind of bus manufactured. The lines needed an optimization and balancing improvement, thus, this study intended to make a contribution to this purpose.A produção de autocarros é um negócio singular devido à variedade de produtos e personalização requerida pelos clientes. Os autocarros são normalmente concebidos com base num chassis, onde é construída a estrutura, seguindo as normas de segurança usuais no sector. A vista exterior dos autocarros pode ser similar, mas existem alguns aspectos construtivos e o interior, que são normalmente definidos pelo cliente, conduzindo a uma elevada personalização do produto. Assim, os autocarros podem ser fabricados numa mesma linha, mas com configurações diferentes, levando normalmente a um complexo processo de montagem que necessita ser convenientemente pensado. Acresce que este tipo de indústria está permanentemente sujeito a uma elevada competitividade e avaliação da sua sustentabilidade, evitando problemas relacionados com o não cumprimento do orçamento inicial. Este trabalho foi desenvolvido numa empresa construtora de autocarros sediada nos arredores do Porto, a qual produz um diversificado leque de tipos de autocarros para aeroportos, turismo, urbanos ou para transporte escolar. A fábrica possui três linhas diferentes de produção, estando cada uma alocada a um tipo diferente de autocarro fabricado. As linhas de produção necessitavam de uma otimização e balanceamento e este estudo pretendeu dar uma contribuição nesse sentido

    Hydraulic Brake Systems for Electrified Road Vehicles: A Down-sizing Approach

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    Down-sizing hydraulic brake systems can is made possible in electrified road vehicles thanks to the braking torque contribution provided by electric machines. Benefits in terms of weight and cost of the system can be ensured in this way. Nevertheless, appropriate care should be taken not to excessively deteriorate the overall electrical energy recovery capability of the electrified vehicle during braking maneuvers. For this reason, a multi-target optimization framework is developed in this paper to down-size hydraulic brake systems for electrified road vehicles while simultaneously maximizing the braking energy recovery capability of the electrified powertrain. Firstly, hydraulic brake system, electrified powertrain and vehicle chassis are modeled in a dedicated simulation platform. Subsequently, particle-swarm optimization is employed as search algorithm to identify optimal sizing parameters for the hydraulic brake system. Sizing variables particularly include diameter and stroke of the master cylinder, electrically assisted booster diameter, front brake piston diameter and rear brake piston diameter. The simulation of homologation tests for safety standards ensures that retained combinations of sizing parameters complies with regulatory requirements. A case study proves that the developed methodology is flexible and effective at rapidly producing several sub-optimal sizing options for both front-wheel drive and rear-wheel drive layouts for a retained battery electric vehicle

    Automotive Stirling Engine Development Program

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    The background and history of the Stirling engine, the technology, materials, components, controls, and systems, and a technical assessment of automotive stirling engines are presented

    Case study of an Organic Rankine Cycle (ORC) for waste heat recovery from an Electric Arc Furnace (EAF)

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    The organic Rankine cycle (ORC) is a mature technology for the conversion of waste heat to electricity. Although many energy intensive industries could benefit significantly from the integration of ORC technology, its current adoption rate is limited. One important reason for this arises from the difficulty of prospective investors and end-users to recognize and, ultimately, realise the potential energy savings from such deployment. In recent years, electric arc furnaces (EAF) have been identified as particularly interesting candidates for the implementation of waste heat recovery projects. Therefore, in this work, the integration of an ORC system into a 100 MWe EAF is investigated. The effect of evaluations based on averaged heat profiles, a steam buffer and optimized ORC architectures is investigated. The results show that it is crucial to take into account the heat profile variations for the typical batch process of an EAF. An optimized subcritical ORC system is found capable of generating a net electrical output of 752 kWe with a steam buffer working at 25 bar. If combined heating is considered, the ORC system can be optimized to generate 521 kWe of electricity, while also delivering 4.52 MW of heat. Finally, an increased power output (by 26% with combined heating, and by 39% without combined heating) can be achieved by using high temperature thermal oil for buffering instead of a steam loop; however, the use of thermal oil in these applications has been until now typically discouraged due to flammability concerns

    Optimization Based Control Strategy for Energy Efficient Decelerations in an Automobile Cruise Controller

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    With global warming and increased uncertainty about future vehicle fuel supply, the need for fuel efficient vehicles is growing. In this Master Thesis, design and implementation of a control strategy for fuel efficient deceleration is presented. The resulting deceleration controller, implemented in Embedded Matlab and Simulink, provides autonomous deceleration functionality to a vehicle cruise controller. Deceleration patterns are produced through online optimization of a cost function comprising fuel consumption and time loss. The cost function is calculated based on navigation information for the predicted driving path, which is also used to detect upcoming deceleration situations. The potential for fuel savings is estimated through simulation, and experiences from tentative driving tests are presented. The optimization approach proves to yield flexibility in balancing fuel savings versus time loss, while being fast enough to be run online as a prototype function in a test vehicle. The deceleration optimizer function could either be used in its current form in future cruise controllers, or as a tool for development of simplified deceleration strategies

    Design and Development of a Multi-material, Cost-competitive, Lightweight Mid-size Sports Utility Vehicle’s Body-in-White

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    Vehicle light-weighting has allowed automotive original equipment manufacturers (OEMs) to improve fuel efficiency, incorporate value-adding features without a weight penalty, and extract better performance. The typical body-in-white (BiW) accounts for up to 40% of the total vehicle mass, making it the focus of light-weighting efforts through a) conceptual redesign b) design optimization using state-of-the-art computer-aided engineering (CAE) tools, and c) use of advanced high strength steels (AHSS), aluminum, magnesium, and/or fiber-reinforced plastic (FRP) composites. However, most of these light-weighting efforts have been focused on luxury/sports vehicles, with a relatively high price range and an average production of 100,000 units/year or less. With increasing sports utility vehicle (SUV) sales in North America, focus has shifted to developing lightweight designs for this segment. Thus, the U.S. Department of Energy’s (DOE) Vehicle Technologies Office has initiated a multi-year research and development program to enable cost-effective light-weighting of a mid-size SUV. The proposed designs shall enable weight reduction of a minimum of 160 lb. (~72.7 kg), with a maximum allowable cost increase of $5 for every pound of weight reduced. The proposed designs shall enable vehicle production rates of 200,000 units/year and will be aimed at retaining the joining/assembly line employed by the OEM. A systems approach has been utilized to develop a multi-material, light-weight redesign of the SUV BiW that meets or exceeds the baseline structural performance. This study delves into the development of design targets for the proposed redesign at the system, sub-assembly, and component levels. Furthermore, results from topology optimization studies on a design volume were assessed to understand the load paths under various loading conditions. Several multi-material concept designs were proposed based on the insights provided by the topology optimization study. Novel multi-material joining methodologies have been incorporated to enable maximum retention of the OEM’s joining and assembly process without significantly increasing cost. This paper presents the systems approach, and results from design studies undertaken to meet the program challenges

    Intelligent systems in manufacturing: current developments and future prospects

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    Global competition and rapidly changing customer requirements are demanding increasing changes in manufacturing environments. Enterprises are required to constantly redesign their products and continuously reconfigure their manufacturing systems. Traditional approaches to manufacturing systems do not fully satisfy this new situation. Many authors have proposed that artificial intelligence will bring the flexibility and efficiency needed by manufacturing systems. This paper is a review of artificial intelligence techniques used in manufacturing systems. The paper first defines the components of a simplified intelligent manufacturing systems (IMS), the different Artificial Intelligence (AI) techniques to be considered and then shows how these AI techniques are used for the components of IMS
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