In recent years, multiple three-phase machines have become increasingly popular due to their reliability and fault tolerance, especially in the propulsion systems of ships, aircraft and vehicles. These systems greatly benefit from the robustness and efficiency offered by such machines. However, a notable challenge for these machines is that harmonics increase with the number of phases, which affects control accuracy and triggers torque oscillations. The phase shift angles between winding sets are one of the most important causes of stator current and torque harmonics. Most of conventional approaches for studying triple-three-phase or nine-phase machines focus on specific phase shifts and lack a comprehensive analysis over a range of phase shifts. This paper discusses the current and torque harmonics of triple three-phase permanent magnet synchronous machines (TTP-PMSM) with different phase shifts. The aim of this paper is to analyse and compare the effect of different phase shifts on harmonic levels. To verify the hypotheses, a Model-in-the-Loop (MiL) simulation environment based on PLECS and MATLAB/Simulink is used to construct the equivalent circuits of the machines and the Field-Oriented Control (FOC) strategy. The mathematical model of the machine is based on a unified transformation that maps the machine quantities into the fundamental αβ-subplane and other subplans, which are shown to reflect both harmonic and zero sequence components. By comparing the amplitudes of current harmonics at different phase shifts, this paper analyses the harmonic dependencies on phase shifts. By making a trade-off between torque harmonics and copper losses caused by current harmonics, the best phase shifts for the design of a triple three-phase PMSM is proposed as (10°, 20°).
{"title":"Current and Torque Harmonics Analysis of Triple Three-Phase Permanent-Magnet Synchronous Machines with Arbitrary Phase Shift Based on Model-in-the-Loop","authors":"Yu Li, Bufan Shi, Jakob Andert","doi":"10.4271/2024-01-3025","DOIUrl":"https://doi.org/10.4271/2024-01-3025","url":null,"abstract":"In recent years, multiple three-phase machines have become increasingly popular due to their reliability and fault tolerance, especially in the propulsion systems of ships, aircraft and vehicles. These systems greatly benefit from the robustness and efficiency offered by such machines. However, a notable challenge for these machines is that harmonics increase with the number of phases, which affects control accuracy and triggers torque oscillations. The phase shift angles between winding sets are one of the most important causes of stator current and torque harmonics. Most of conventional approaches for studying triple-three-phase or nine-phase machines focus on specific phase shifts and lack a comprehensive analysis over a range of phase shifts. This paper discusses the current and torque harmonics of triple three-phase permanent magnet synchronous machines (TTP-PMSM) with different phase shifts. The aim of this paper is to analyse and compare the effect of different phase shifts on harmonic levels. To verify the hypotheses, a Model-in-the-Loop (MiL) simulation environment based on PLECS and MATLAB/Simulink is used to construct the equivalent circuits of the machines and the Field-Oriented Control (FOC) strategy. The mathematical model of the machine is based on a unified transformation that maps the machine quantities into the fundamental αβ-subplane and other subplans, which are shown to reflect both harmonic and zero sequence components. By comparing the amplitudes of current harmonics at different phase shifts, this paper analyses the harmonic dependencies on phase shifts. By making a trade-off between torque harmonics and copper losses caused by current harmonics, the best phase shifts for the design of a triple three-phase PMSM is proposed as (10°, 20°).","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141688253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andreas Dieing, Hans-Christian Reuss, Marco Schlüter
Driving simulators allow the testing of driving functions, vehicle models and acceptance assessment at an early stage. For a real driving experience, it's necessary that all immersions are depicted as realistically as possible. When driving manually, the perceived haptic steering wheel torque plays a key role in conveying a realistic steering feel. To ensure this, complex multi-body systems are used with numerous of parameters that are difficult to identify. Therefore, this study shows a method how to generate a realistic steering feel with a nonlinear open-loop model which only contains significant parameters, particularly the friction of the steering gear. This is suitable for the steering feel in the most driving on-center area. Measurements from test benches and real test drives with an Electric Power Steering (EPS) were used for the Identification and Validation of the model. The open-loop architecture on steering rack level shows adequate results and generate a nearly delay-free response of the expected steering torque. Further it allows the expansion to a closed-loop or a hybrid model with neural networks. This makes it particularly suitable for force feedback systems in driving simulators or Steer-By-Wire Systems.
{"title":"On-Center Steering Model for Realistic Steering Feel based on Real Measurement Data","authors":"Andreas Dieing, Hans-Christian Reuss, Marco Schlüter","doi":"10.4271/2024-01-2994","DOIUrl":"https://doi.org/10.4271/2024-01-2994","url":null,"abstract":"Driving simulators allow the testing of driving functions, vehicle models and acceptance assessment at an early stage. For a real driving experience, it's necessary that all immersions are depicted as realistically as possible. When driving manually, the perceived haptic steering wheel torque plays a key role in conveying a realistic steering feel. To ensure this, complex multi-body systems are used with numerous of parameters that are difficult to identify. Therefore, this study shows a method how to generate a realistic steering feel with a nonlinear open-loop model which only contains significant parameters, particularly the friction of the steering gear. This is suitable for the steering feel in the most driving on-center area. Measurements from test benches and real test drives with an Electric Power Steering (EPS) were used for the Identification and Validation of the model. The open-loop architecture on steering rack level shows adequate results and generate a nearly delay-free response of the expected steering torque. Further it allows the expansion to a closed-loop or a hybrid model with neural networks. This makes it particularly suitable for force feedback systems in driving simulators or Steer-By-Wire Systems.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141687973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Robin Schmelcher, A. Kulzer, Thomas Gal, A. Vacca, Marco Chiodi
For the purpose of achieving carbon-neutrality in the mobility sector by 2050, hydrogen can play a crucial role as an alternative energy carrier, not only for direct usage in fuel cell-powered vehicles, but also for fueling internal combustion engines. This paper focuses on the numerical investigation of high-pressure hydrogen injection and the mixture formation inside a high-tumble engine with a conventional liquid fuel injector for passenger cars. Since the traditional 3D-CFD approach of simulating the inner flow of an injector requires a very high spatial and temporal resolution, the enormous computational effort, especially for full engine simulations, is a big challenge for an effective virtual development of modern engines. An alternative and more pragmatic lagrangian 3D-CFD approach offers opportunities for a significant reduction in computational effort without sacrificing reliability. The detailed and the lagrangian approach are both validated against optical measurements inside a spray chamber, provided by Robert Bosch GmbH to ensure an accurate reproduction of the injection process in the simulation. The investigation shows, that the lagrangian approach enables 30 times bigger time steps, while maintaining comparable results. The effects on jet propagation and mixture formation are examined in a virtual 3D-CFD single cylinder engine test bench under the consideration of a boosted high tumble engine concept and direct injection up to 220 bar. A variation of injection timings and the air-to-fuel ratio are carried out at two load points and validated with the test bench data. By means of the matching simulation results, it is therefore possible to explain trends in engine behavior and make detailed statements about the interaction of the hydrogen high-pressure injection and the mixture formation. Particular attention was hereby paid to the influences on gas exchange losses, NOx emissions and engine efficiency.
{"title":"Numerical Investigation of Injection and Mixture Formation in Hydrogen Combustion Engines by Means of Different 3D-CFD Simulation Approaches","authors":"Robin Schmelcher, A. Kulzer, Thomas Gal, A. Vacca, Marco Chiodi","doi":"10.4271/2024-01-3007","DOIUrl":"https://doi.org/10.4271/2024-01-3007","url":null,"abstract":"For the purpose of achieving carbon-neutrality in the mobility sector by 2050, hydrogen can play a crucial role as an alternative energy carrier, not only for direct usage in fuel cell-powered vehicles, but also for fueling internal combustion engines. This paper focuses on the numerical investigation of high-pressure hydrogen injection and the mixture formation inside a high-tumble engine with a conventional liquid fuel injector for passenger cars. Since the traditional 3D-CFD approach of simulating the inner flow of an injector requires a very high spatial and temporal resolution, the enormous computational effort, especially for full engine simulations, is a big challenge for an effective virtual development of modern engines. An alternative and more pragmatic lagrangian 3D-CFD approach offers opportunities for a significant reduction in computational effort without sacrificing reliability. The detailed and the lagrangian approach are both validated against optical measurements inside a spray chamber, provided by Robert Bosch GmbH to ensure an accurate reproduction of the injection process in the simulation. The investigation shows, that the lagrangian approach enables 30 times bigger time steps, while maintaining comparable results. The effects on jet propagation and mixture formation are examined in a virtual 3D-CFD single cylinder engine test bench under the consideration of a boosted high tumble engine concept and direct injection up to 220 bar. A variation of injection timings and the air-to-fuel ratio are carried out at two load points and validated with the test bench data. By means of the matching simulation results, it is therefore possible to explain trends in engine behavior and make detailed statements about the interaction of the hydrogen high-pressure injection and the mixture formation. Particular attention was hereby paid to the influences on gas exchange losses, NOx emissions and engine efficiency.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141684217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francesco Pucillo, Federico Millo, A. Piano, Sergio Giordana, Nicola Rapetto, Fabio Paulicelli
Nowadays, green hydrogen can play a crucial role in a successful clean energy transition, thus reaching net zero emissions in the transport sector. Moreover, hydrogen exploitation in internal combustion engines is favored by its suitable combustion properties and quasi-zero pollutant emissions. High flame speeds enable a lean combustion approach, which provides high efficiency and reduces NOx emissions. However, high airflow rates are required to achieve the load levels typical of heavy-duty applications. In this framework, the present study aims at investigating the required boosting system of a 6-cylinder, 13-litre heavy-duty spark ignition engine through 1D numerical simulation. A comparison among various architectures of the turbocharging system and the size of each component is presented, thus highlighting the limitations and potentialities of each architecture and providing important insights for the selection of the best turbocharging system.
{"title":"Turbocharging System Selection for a Hydrogen-Fuelled Spark-Ignition Internal Combustion Engine for Heavy-Duty Applications","authors":"Francesco Pucillo, Federico Millo, A. Piano, Sergio Giordana, Nicola Rapetto, Fabio Paulicelli","doi":"10.4271/2024-01-3019","DOIUrl":"https://doi.org/10.4271/2024-01-3019","url":null,"abstract":"Nowadays, green hydrogen can play a crucial role in a successful clean energy transition, thus reaching net zero emissions in the transport sector. Moreover, hydrogen exploitation in internal combustion engines is favored by its suitable combustion properties and quasi-zero pollutant emissions. High flame speeds enable a lean combustion approach, which provides high efficiency and reduces NOx emissions. However, high airflow rates are required to achieve the load levels typical of heavy-duty applications. In this framework, the present study aims at investigating the required boosting system of a 6-cylinder, 13-litre heavy-duty spark ignition engine through 1D numerical simulation. A comparison among various architectures of the turbocharging system and the size of each component is presented, thus highlighting the limitations and potentialities of each architecture and providing important insights for the selection of the best turbocharging system.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Saur, Patrick Heidegger, Christoph Naeger, Stefan Becker
In electrified vehicles, auxiliary units can be a dominant source of noise, one of which is the refrigerant scroll compressor. Compared to vehicles with combustion engines, e-vehicles require larger refrigerant compressors, as in addition to the interior, also the battery and the electric motors have to be cooled. Currently, scroll compressors are widely used in the automotive industry, which generate one pressure pulse per revolution due to their discontinuous compression principle. This results in speed-dependent pressure fluctuations as well as higher-harmonic pulsations that arise from reflections. These fluctuations spread through the refrigeration cycle and cause the vibration excitation of refrigerant lines and heat exchangers. The sound transmission path in the air conditioning heat exchanger integrated in the dashboard is particularly critical. Various silencer configurations can be used to dampen these pulsations. This paper compares the acoustic and thermodynamic performance of two mufflers and a resonator for different operating points. It is shown that the installation of the various flow silencers has no influence on the thermodynamic efficiency of the refrigeration cycle. Measurements of the pressure pulsations before and after the flow silencer are carried out using a refrigeration cycle acoustic test rig. The experimentally determined transmission loss values are compared with impedance tube measurement results and analytically calculated sound attenuation curves of the mufflers. The three different flow silencers dampen the pressure pulsations in the refrigeration cycle across a wide frequency range. The single-chamber muffler has the highest transmission loss in the low-frequency range up to 200 Hz and attenuates the high-amplitude 1st order pressure pulsations by up to 20 dB. The multi-chamber muffler achieves a transmission loss of up to 30 dB in the higher frequency range from 400 Hz. For both mufflers, there is good agreement between the measured values in the refrigeration cycle, in the impedance tube and the analytically calculated values. For the resonator, the measured transmission loss in the refrigeration cycle is significantly lower than in the impedance tube. The transmission loss of the resonator in the refrigeration cycle is constant at approx. 5 dB up to 600 Hz. The findings on the operation principle and damping performance of different refrigerant cycle silencers enable the reduction of flow-induced noise in thermomanagement system components in vehicles.
{"title":"Reduction of Flow-Induced Noise in Refrigeration Cycles","authors":"L. Saur, Patrick Heidegger, Christoph Naeger, Stefan Becker","doi":"10.4271/2024-01-2972","DOIUrl":"https://doi.org/10.4271/2024-01-2972","url":null,"abstract":"In electrified vehicles, auxiliary units can be a dominant source of noise, one of which is the refrigerant scroll compressor. Compared to vehicles with combustion engines, e-vehicles require larger refrigerant compressors, as in addition to the interior, also the battery and the electric motors have to be cooled. Currently, scroll compressors are widely used in the automotive industry, which generate one pressure pulse per revolution due to their discontinuous compression principle. This results in speed-dependent pressure fluctuations as well as higher-harmonic pulsations that arise from reflections. These fluctuations spread through the refrigeration cycle and cause the vibration excitation of refrigerant lines and heat exchangers. The sound transmission path in the air conditioning heat exchanger integrated in the dashboard is particularly critical. Various silencer configurations can be used to dampen these pulsations. This paper compares the acoustic and thermodynamic performance of two mufflers and a resonator for different operating points. It is shown that the installation of the various flow silencers has no influence on the thermodynamic efficiency of the refrigeration cycle. Measurements of the pressure pulsations before and after the flow silencer are carried out using a refrigeration cycle acoustic test rig. The experimentally determined transmission loss values are compared with impedance tube measurement results and analytically calculated sound attenuation curves of the mufflers. The three different flow silencers dampen the pressure pulsations in the refrigeration cycle across a wide frequency range. The single-chamber muffler has the highest transmission loss in the low-frequency range up to 200 Hz and attenuates the high-amplitude 1st order pressure pulsations by up to 20 dB. The multi-chamber muffler achieves a transmission loss of up to 30 dB in the higher frequency range from 400 Hz. For both mufflers, there is good agreement between the measured values in the refrigeration cycle, in the impedance tube and the analytically calculated values. For the resonator, the measured transmission loss in the refrigeration cycle is significantly lower than in the impedance tube. The transmission loss of the resonator in the refrigeration cycle is constant at approx. 5 dB up to 600 Hz. The findings on the operation principle and damping performance of different refrigerant cycle silencers enable the reduction of flow-induced noise in thermomanagement system components in vehicles.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dominik Rehm, Jonathan Krost, Martin Meywerk, Walter Czarnetzki
The courier express parcel service industry (CEP industry) has experienced significant changes in the recent years due to increasing parcel volume. At the same time, the electrification of the vehicle fleets poses additional challenges. A major advantage of battery electric CEP vehicles compared to internal combustion engine vehicles is the ability to regenerate the kinetic energy of the vehicle in the frequent deceleration phases during parcel delivery. If the battery is cold, the maximum regenerative power of the powertrain is limited by a reduced chemical reaction rate inside the battery. In general, the maximum charging power of the battery depends on the state of charge and the battery temperature. Due to the low power demand for driving during CEP operation, the battery self-heating is comparably low. Without active conditioning of the battery, potential of regenerating energy is partially lost because the friction brake needs to absorb kinetic energy whenever the cold battery’s limit is exceeded. This paper proposes an optimization-based strategy for the battery thermal management of CEP vehicles. The tradeoff between the cost of battery heating and the benefit of regenerative braking is investigated under cold ambient conditions. For this purpose, a nonlinear model predictive control approach is developed to maximize the overall vehicle efficiency depending on the upcoming driving task by selective battery heating. The evaluation shows that the increase in overall efficiency depends on the electric efficiency of the battery heating system, the ambient conditions, the intensity and frequency of the deceleration phases, and the usage behavior of the vehicle. Based on the assumption that the driving cycle and ambient conditions can be accurately predicted, the model-in-the-loop simulation indicates a reduction in energy consumption of up to 3.3 % with an electric coolant heater and up to 9.6 % with an ambient heat pump.
{"title":"Optimization-Based Battery Thermal Management for Improved Regenerative Braking in CEP Vehicles","authors":"Dominik Rehm, Jonathan Krost, Martin Meywerk, Walter Czarnetzki","doi":"10.4271/2024-01-2974","DOIUrl":"https://doi.org/10.4271/2024-01-2974","url":null,"abstract":"The courier express parcel service industry (CEP industry) has experienced significant changes in the recent years due to increasing parcel volume. At the same time, the electrification of the vehicle fleets poses additional challenges. A major advantage of battery electric CEP vehicles compared to internal combustion engine vehicles is the ability to regenerate the kinetic energy of the vehicle in the frequent deceleration phases during parcel delivery. If the battery is cold, the maximum regenerative power of the powertrain is limited by a reduced chemical reaction rate inside the battery. In general, the maximum charging power of the battery depends on the state of charge and the battery temperature. Due to the low power demand for driving during CEP operation, the battery self-heating is comparably low. Without active conditioning of the battery, potential of regenerating energy is partially lost because the friction brake needs to absorb kinetic energy whenever the cold battery’s limit is exceeded. This paper proposes an optimization-based strategy for the battery thermal management of CEP vehicles. The tradeoff between the cost of battery heating and the benefit of regenerative braking is investigated under cold ambient conditions. For this purpose, a nonlinear model predictive control approach is developed to maximize the overall vehicle efficiency depending on the upcoming driving task by selective battery heating. The evaluation shows that the increase in overall efficiency depends on the electric efficiency of the battery heating system, the ambient conditions, the intensity and frequency of the deceleration phases, and the usage behavior of the vehicle. Based on the assumption that the driving cycle and ambient conditions can be accurately predicted, the model-in-the-loop simulation indicates a reduction in energy consumption of up to 3.3 % with an electric coolant heater and up to 9.6 % with an ambient heat pump.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141684281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the COP28 decisions the world is thriving for a future net-zero-CO2 society and the and current regulation acts, the energy infrastructure is changing in direction of renewables in energy production. All industry sectors will extend their share of direct or indirect electrification. The question might arise if the build-up of the renewables in energy production is fast enough. Demand and supply might not match in the short- and mid-term.The paper will discuss the roadmaps, directions and legislative boundary parameter in the regenerative energy landscape and their regional differences. National funding on renewables will gain an increasing importance to accelerate the energy transformation. The are often competing in attracting the same know-how on a global scale. In addition the paper includes details about energy conversion, efficiency as well as potential transport scenarios from production to the end consumer. Technologies are compared in respect of their TLR level and maturity for the market application. Furthermore the need for energy buffering on molecule or electron basis, availability and technical options will be evaluated. Finally the paper concludes with scenario calculations considering technology readiness and TCO for production, transport and infrastructure. Comparing all electricity based scenarios including molecules – respectively hydrogen and e-fuel are part of the evaluation.
{"title":"How Can a Sustainable Energy Infrastructure Based on Renewable Fuels Contribute to Global Carbon Neutrality?","authors":"Martin Rothbart","doi":"10.4271/2024-01-3023","DOIUrl":"https://doi.org/10.4271/2024-01-3023","url":null,"abstract":"With the COP28 decisions the world is thriving for a future net-zero-CO2 society and the and current regulation acts, the energy infrastructure is changing in direction of renewables in energy production. All industry sectors will extend their share of direct or indirect electrification. The question might arise if the build-up of the renewables in energy production is fast enough. Demand and supply might not match in the short- and mid-term.The paper will discuss the roadmaps, directions and legislative boundary parameter in the regenerative energy landscape and their regional differences. National funding on renewables will gain an increasing importance to accelerate the energy transformation. The are often competing in attracting the same know-how on a global scale. In addition the paper includes details about energy conversion, efficiency as well as potential transport scenarios from production to the end consumer. Technologies are compared in respect of their TLR level and maturity for the market application. Furthermore the need for energy buffering on molecule or electron basis, availability and technical options will be evaluated. Finally the paper concludes with scenario calculations considering technology readiness and TCO for production, transport and infrastructure. Comparing all electricity based scenarios including molecules – respectively hydrogen and e-fuel are part of the evaluation.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the context of urban smart mobility, vehicles have to communicate with each other, surrounding infrastructure, and other traffic participants. By using Vehicle2X communication, it is possible to exchange the vehicles’ position, driving dynamics data, or driving intention. This concept yields the use for cooperative driving in urban environments. Based on current V2X-communication standards, a methodology for cooperative driving of automated vehicles in mixed traffic scenarios is presented. Initially, all communication participants communicate their dynamic data and planned trajectory, based on which a prioritization is calculated. Therefore, a decentralized cooperation algorithm is introduced. The approach of this algorithm is that every traffic scenario is translatable to a directed graph, based in which a solution for the cooperation problem is computed via an optimization algorithm. This solution is either computed decentralized by various traffic participants, who share and compare their solutions in order to get an optimal one, or centralized by a single computation unit, such as smart infrastructure systems. The cooperation participants negotiate the cooperative driving maneuver via a chain like validation approach, since the communication protocol does not require any handshake by design. Finally, all cooperation participants carry out the optimized and negotiated cooperative driving maneuver. The presented algorithm is validated in a multi-vehicle simulation. Different optimization heuristics are compared, ranging from traditional approaches to machine learning algorithms. The methods' behavior with regard to increasing model complexities is evaluated based on a representative catalogue of scenarios. Finally, the algorithm is validated in a real world proving ground test. These validations show that the introduced methodology provides significantly more efficient cooperation strategies compared to traditional, infrastructure-controlled approaches. Additionally, the presented approach is conflict-free by design.
{"title":"Graph based Cooperation Strategies for Automated Vehicles in Mixed Traffic","authors":"Maximilian Flormann, Roman Henze","doi":"10.4271/2024-01-2982","DOIUrl":"https://doi.org/10.4271/2024-01-2982","url":null,"abstract":"In the context of urban smart mobility, vehicles have to communicate with each other, surrounding infrastructure, and other traffic participants. By using Vehicle2X communication, it is possible to exchange the vehicles’ position, driving dynamics data, or driving intention. This concept yields the use for cooperative driving in urban environments. Based on current V2X-communication standards, a methodology for cooperative driving of automated vehicles in mixed traffic scenarios is presented. Initially, all communication participants communicate their dynamic data and planned trajectory, based on which a prioritization is calculated. Therefore, a decentralized cooperation algorithm is introduced. The approach of this algorithm is that every traffic scenario is translatable to a directed graph, based in which a solution for the cooperation problem is computed via an optimization algorithm. This solution is either computed decentralized by various traffic participants, who share and compare their solutions in order to get an optimal one, or centralized by a single computation unit, such as smart infrastructure systems. The cooperation participants negotiate the cooperative driving maneuver via a chain like validation approach, since the communication protocol does not require any handshake by design. Finally, all cooperation participants carry out the optimized and negotiated cooperative driving maneuver. The presented algorithm is validated in a multi-vehicle simulation. Different optimization heuristics are compared, ranging from traditional approaches to machine learning algorithms. The methods' behavior with regard to increasing model complexities is evaluated based on a representative catalogue of scenarios. Finally, the algorithm is validated in a real world proving ground test. These validations show that the introduced methodology provides significantly more efficient cooperation strategies compared to traditional, infrastructure-controlled approaches. Additionally, the presented approach is conflict-free by design.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EU legislation provides for only local CO2 emission-free vehicles to be allowed in individual passenger transport by 2035. In addition, the directive provides for fuels from renewable sources, i.e. defossilised fuels. This development leads to three possible energy sources or forms of energy for use in individual transport. The first possibility is charging with electricity generated from renewable sources, the second possibility is hydrogen generated from renewable sources or blue production path. The third possibility is the use of renewable fuels, also called e-fuels. These fuels are produced from atmospheric CO2 and renewable hydrogen. Possible processes for this are, for example, methanol or Fischer-Tropsch synthesis. The production of these fuels is very energy-intensive and large amounts of renewable electricity are needed. Thus, national production of these fuels in the EU is inefficient in terms of cost and carbon footprint due to the low utilisation rate of renewable energy plants. Outsourcing these processes to regions where renewable energy production takes place under high utilisation rates and thus the amount of installed capacity can be reduced seems to make sense. Nevertheless, it is to be expected that the costs of the renewably produced fuel will be considerably higher than for the respective fossil equivalent. This makes the production and distribution chain susceptible to fraud by mixing it with, or substituting it for, fossil fuel. This problem can only be controlled by appropriate regulations and controls. This paper presents different options for product control and certification, both for the global and the EU trade area. It conceptually discusses different procedures for control, certification and fuel labelling. First, the draft for a global, certificate-based system for production volume control is presented. This draft enables independent trading of certificates and the product. This makes it possible to implement both pure certificate trading and product-linked certificate trading. Thus, each trading zone can implement the system that suits them best, without disturbing the control of the global production volume. In a second step, an automated monitoring system for tracking imported renewable fuels in the EU trading zone is presented. This is done via a second certification authority and continuous digital and governmental monitoring. In a third step, possibilities are presented with which the fuel or the refuelling in the vehicle can be monitored. Finally, a conclusion is given on the practicability of such a monitoring system.
{"title":"Traceability E-Fuels 2035","authors":"Tobias Stoll, A. Kulzer, Hans-Juergen Berner","doi":"10.4271/2024-01-3022","DOIUrl":"https://doi.org/10.4271/2024-01-3022","url":null,"abstract":"EU legislation provides for only local CO2 emission-free vehicles to be allowed in individual passenger transport by 2035. In addition, the directive provides for fuels from renewable sources, i.e. defossilised fuels. This development leads to three possible energy sources or forms of energy for use in individual transport. The first possibility is charging with electricity generated from renewable sources, the second possibility is hydrogen generated from renewable sources or blue production path. The third possibility is the use of renewable fuels, also called e-fuels. These fuels are produced from atmospheric CO2 and renewable hydrogen. Possible processes for this are, for example, methanol or Fischer-Tropsch synthesis. The production of these fuels is very energy-intensive and large amounts of renewable electricity are needed. Thus, national production of these fuels in the EU is inefficient in terms of cost and carbon footprint due to the low utilisation rate of renewable energy plants. Outsourcing these processes to regions where renewable energy production takes place under high utilisation rates and thus the amount of installed capacity can be reduced seems to make sense. Nevertheless, it is to be expected that the costs of the renewably produced fuel will be considerably higher than for the respective fossil equivalent. This makes the production and distribution chain susceptible to fraud by mixing it with, or substituting it for, fossil fuel. This problem can only be controlled by appropriate regulations and controls. This paper presents different options for product control and certification, both for the global and the EU trade area. It conceptually discusses different procedures for control, certification and fuel labelling. First, the draft for a global, certificate-based system for production volume control is presented. This draft enables independent trading of certificates and the product. This makes it possible to implement both pure certificate trading and product-linked certificate trading. Thus, each trading zone can implement the system that suits them best, without disturbing the control of the global production volume. In a second step, an automated monitoring system for tracking imported renewable fuels in the EU trading zone is presented. This is done via a second certification authority and continuous digital and governmental monitoring. In a third step, possibilities are presented with which the fuel or the refuelling in the vehicle can be monitored. Finally, a conclusion is given on the practicability of such a monitoring system.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jan Marcel Hübner, Mathias Hähnel, Sven Lange, Matthias Lemke, Ivan Joksimovic
In order to improve the efficiency of passenger cars, developments focus on decreasing their aerodynamic drag, part of which is caused by cooling air. Thus, car manufacturers try to seal the cooling air path to prevent leakage flows. Nevertheless, gaps between the single components of the cooling air path widen due to the deformation of components under aerodynamic load. For simulating the cooling airflow utilization ratio (CAUR), computational fluid dynamics (CFD) simulations are used, which neglect component deformation. In this paper, a computational method aiming at sufficient gap resolution and determining the CAUR of passenger cars under the consideration of component deformation is developed. Therefore, a partitioned approach of fluid structure interaction (FSI) simulations is used. The fluid field is simulated in OpenFOAM, whereas the structural simulations are conducted using Pam-Crash. In order to validate the simulation results, the CAUR of a battery electric and an internal combustion engine powered vehicle is determined at a specifically developed cooling air test rig. Additionally, wind tunnel measurements determining wall pressures and component deformations are conducted. Furthermore, an experimental method was developed to measure three-dimensional deformations applying the “Structure from Motion” method to phosphorescent marker points. It could be shown, that areas of deformation can be detected by the developed simulation method and that the deformations negatively influence the CAUR. Comparing the results of the FSI simulations to single CFD simulations, this work was able to reduce the maximum estimation error of the CAUR from +12 %P to +3 %P. Finally, remaining error sources are outlined.
{"title":"Computational Method to Determine the Cooling Airflow Utilization Ratio of Passenger Cars Considering Component Deformation","authors":"Jan Marcel Hübner, Mathias Hähnel, Sven Lange, Matthias Lemke, Ivan Joksimovic","doi":"10.4271/2024-01-2975","DOIUrl":"https://doi.org/10.4271/2024-01-2975","url":null,"abstract":"In order to improve the efficiency of passenger cars, developments focus on decreasing their aerodynamic drag, part of which is caused by cooling air. Thus, car manufacturers try to seal the cooling air path to prevent leakage flows. Nevertheless, gaps between the single components of the cooling air path widen due to the deformation of components under aerodynamic load. For simulating the cooling airflow utilization ratio (CAUR), computational fluid dynamics (CFD) simulations are used, which neglect component deformation. In this paper, a computational method aiming at sufficient gap resolution and determining the CAUR of passenger cars under the consideration of component deformation is developed. Therefore, a partitioned approach of fluid structure interaction (FSI) simulations is used. The fluid field is simulated in OpenFOAM, whereas the structural simulations are conducted using Pam-Crash. In order to validate the simulation results, the CAUR of a battery electric and an internal combustion engine powered vehicle is determined at a specifically developed cooling air test rig. Additionally, wind tunnel measurements determining wall pressures and component deformations are conducted. Furthermore, an experimental method was developed to measure three-dimensional deformations applying the “Structure from Motion” method to phosphorescent marker points. It could be shown, that areas of deformation can be detected by the developed simulation method and that the deformations negatively influence the CAUR. Comparing the results of the FSI simulations to single CFD simulations, this work was able to reduce the maximum estimation error of the CAUR from +12 %P to +3 %P. Finally, remaining error sources are outlined.","PeriodicalId":510086,"journal":{"name":"SAE Technical Paper Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141684677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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