FISITA World Congress 2021 - Technical Programme最新文献

{"title":"Virtual Modelling of Real- Driving Conditions for Early Evaluation and Validation of Vehicles Design","authors":"M. R. Arroyos, Xavier Bertolí, Fancisco Diaz, Didac Didac, Cano Pablo, Salat Roger","doi":"10.46720/f2021-adm-130","DOIUrl":"https://doi.org/10.46720/f2021-adm-130","url":null,"abstract":"\"The vehicle validation at the end of the development process has to guarantee the vehicle will fulfill the expected reliability, consumption, emission, safety and performances in the variety of possible use- case scenarios, ranging from city to hilly roads and autobahnsmotorways, from extremely hot to extremely cold conditions and from gentle to aggressive driving. IDIADA is a leading company in validation for real- driving conditions, conducting over 15.000.000 km per year in the five continents. However, problem-solving in the validation phase is commonly difficult and expensive. For this reason, real- driving conditions are gaining relevance in the vehicle design phase, hence, the need arises to shift these real conditions to a model basedmodel-based development process in order to perform target setting and early virtual validation for real- driving conditions. For the modelling of the different real conditions a data collection process must be carried out. The data acquisition system and specific instrumentation typically represent a high- cost activity that hinders the data collection coverage. For this purpose, IDIADA has developed the NAVIMU-20, a cost- effective, versatile, compact and accurate data acquisition system that involves navigation and inertial measurements as well as logging functionality for collectingon all the data required to generate virtual mission profiles. This paper covers the development of this solution, starting with the measurements definition, standardization of the logs format for compatibility with the post-processing system, the comparison and verification with high- performance data acquisition systems to validate and ensure the data quality, the and algorithm development for the slope calculation with post- processing. Finally, the generated mission profiles are validated to calculate powertrain demand, through correlation between calculated operative point and measured torque for sample routes. As a result of the activity, the paper shows the application of a mission profile to virtually simulate the implications in real use of a combustion and a hybrid vehicle oin the same route. This methodology aims to build a real- driving usage profile database with wide coverage of the five continents suitable for early virtual evaluation of real- driving implications in powertrain in terms of consumption, emissions, durability, driveability, cooling and thermal comfort.\"","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121369829","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}

{"title":"Scenario Based Testing of Automated Driving Systems: A Literature Survey","authors":"Demin Nalic, T. Mihalj, A. Eichberger, Maximilian Bäumler, Matthias Lehmann","doi":"10.46720/f2020-acm-096","DOIUrl":"https://doi.org/10.46720/f2020-acm-096","url":null,"abstract":"Scenario based methods for testing and validation of automated driving systems in virtual test environments are gaining importance and becoming an important component for verification and validation processes of automated driving systems. The high system complexity of such systems and the high testing costs lead to an exponential increase of test efforts for real world testing. Recent research works have shown that it is necessary to drive and test billions of kilometers to ensure the safety and reliability of automated driving systems. This amount of test kilometers is far from possible and achievable for any test procedure regarding the time and costs. Using different methods and procedures it is possible to reduce the number of scenarios, which should be tested to approve the safety and reliability of automated driving systems. The scenario space consisting of critical and non-critical scenarios and the test effort can be reduced to an infinite and comprehensible amount of relevant scenarios for the system under test. Using scenario and simulation based approaches this effort can be efficiently reduced concerning the costs and time. The biggest challenges hereby are the detection and selection of a suitable scenarios and simulation environments or platforms for the system under test. Besides, suitable safety metrics are essential for the detection, evaluation, and reduction of relevant scenarios for testing of automated driving systems. Current scientific work offers various strategies and approaches for generating relevant scenarios for automated driving systems. All of them have their advantages and disadvantages related to the used virtual environment, vehicle model, traffic model, and the integration complexity. This paper presents a survey through different approaches, methods, and safety metrics for scenario generation and evaluation for testing and validation of automated driving systems. The reader should get a state of the art overview on scenario based approaches of automated driving systems.","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125138480","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}

{"title":"Assessment of the Influence of Human Body Diversity on Passive Safety Systems: A State-of-the-art Overview","authors":"Franz Plaschkies, O. Vaculín, A. Schumacher","doi":"10.46720/f2021-pif-071","DOIUrl":"https://doi.org/10.46720/f2021-pif-071","url":null,"abstract":"In technical development, the product, including its robustness, is determined through the requirements and tests. In many cases, the robustness is validated by several sample tests. This paper focuses on the development process in the field of systems for the passive safety of vehicle occupants. The state-of-the-art in the development and assessment of such systems is based on both physical and virtual testing. The physical tests are mainly used for validation and final approval purposes. The prominent role of virtual methods is played with a digital twin of the physical configuration. For the assessment of the interaction of the vehicle with its occupants, few anthropometric configurations are usually tested. Assuming a Gaussian distribution of body shapes in a population, the 5th, 50th, and 95th percentiles crash test dummies are widely applied. Nevertheless, the human body does not necessarily vary in a whole, but in all its measures. The reason for using only those few percentiles lies in the limitation of the resources, especially for physical testing, and the advantage of synchronizing physical and virtual testing. Due to the limitations, the potential of virtual methods cannot be used fully. In this state-of-the-art overview paper, the approaches to speed up and broaden the testing during the system's development to increase the solutions' robustness are presented. The state-of-the-art occupant safety development methods are summarized, including the human representation, tested scenarios, as well as evaluated criteria. The second part of this paper reviews available databases for human body measurements. The transition between the anthropometric data to virtual models plays an essential role in the virtual assessment. This part also includes metamodeling approaches to reduce the parameter space and methods for the automated creation of virtual models. Recent studies using multibody systems or finite element analysis are reviewed. Finally, relevant studies on accelerating the virtual process are presented together with approaches from machine learning, which has rapidly developed in recent years. The comparison of the approaches in the passive safety domain is presented. The supervised learning algorithms are taken as a basis for estimating simulation results for different anthropometric configurations. On the one hand, such algorithms can provide a significant reduction of the development time. However, on the other hand, they need a vast amount of data, while generating simulation results can be a time-consuming process. Therefore, also approaches to overcome this obstacle are also mentioned.","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122327203","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}

{"title":"The New Solutions of Energy Utilization of the Exhaust Gases of the Internal Combustion Engines Through Hybrid Turbochargers","authors":"R. Chiriac, A. Chiru","doi":"10.46720/f2020-adm-081","DOIUrl":"https://doi.org/10.46720/f2020-adm-081","url":null,"abstract":"Internal combustion engines have an operating efficiency which can be exploited to increase their performance. Part of the residual gases can be recovered through technical solutions such as turbocharging. The turbocharging solution is one of the most popular technical solutions for increasing the energy performance of internal combustion engines. A turbocharger is used for the turbocharging process. The turbocharger can also contribute with new technical solutions to increase the energy performance of the internal combustion engines. One of the solutions proposed for the theoretical and experimental research is the hybrid turbocharger, which has a double function, namely to compress the fresh air for the internal combustion engine, and to generate electricity for the electric engine of the vehicle both for consumption and to be stored in batteries. This article aims to present the result of the experimental research of the hybrid turbocharger, simulate and validate the new solutions for increasing the energy performance of internal combustion engines through hybrid turbochargers using a coupled electric generator. The simulations will be made using the AMESim Sofware developed by Siemens to demonstrate the efficiency of the new solutions such as a hybrid turbocharger through calculations. The tests will be carried out with the test bed CIMAT. CIMAT test bed is a machine which provides high pressure air which simulates the combustion gases of an engine. The purpose of the CIMAT test bed is to rotate the hybrid turbocharger turbine and the compressor wheel as well. More technical information about the hybrid turbocharger test will be presented in the scientific article, as well as constructive details. Based on the technical information and input data in the first phase, an application for the simulation and validation of the prototype will be made to demonstrate the great potential of the turbocharger to also produce green energy.","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129471818","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}

{"title":"Suspension damping force control algorithms using vehicle states with driver and road inputs","authors":"Shingo Koumura, Yan-qi Liu, Masaki Yamamoto","doi":"10.46720/f2021-vdc-107","DOIUrl":"https://doi.org/10.46720/f2021-vdc-107","url":null,"abstract":"\"The damping force control system of the shock absorber is relatively simply constituted and adopted widely. Skyhook semi-active control logic is representative algorithm which reduces vehicle vibration due to road input and vehicle posture changes such as roll or pitch angle due to driver operation input. However, it is difficult to reduce both of vehicle vibration and vehicle posture change when road input and driver operation input occur simultaneously like a case to run through the corner with road undulation. For this problem, control method considering the frequency range difference between vehicle behavior due to road input and that due to driver operation input is suggested. Also, the effectiveness of changing control constant depending on the vehicle state such as tire contact load is reported. In this paper vehicle behavior due to road input and that of driver operation input is calculated for analysis of skyhook shock absorber control using random wave which simulated actual road surface and driver maneuver.Non-linearity caused by the difference between target damping force and actual damping force increases vehicle behavior due to driver operation input in case of combination with road input. Also amplitude dependency was evaluated by changing the scale of road and driver input. As a result, it was confirmed that the effect of combination input is particularly remarkable when road surface input is large compared to driver input. Countermeasure control logic with additional damping force calculated with vehicle model is proposed to decrease vehicle behavior due to driver operation input. The vehicle model based on 3DOF of roll, lateral and yaw direction estimates vehicle behavior due to driver input. In addition, improvement of the estimation precision was attempted by digitizing suspension properties considering change of the damping force due to shock absorber damping force control in a frequency domain. The estimated state accuracy and the vehicle performance improvement were confirmed in actual vehicle tests.\"","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129750867","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}

{"title":"Evaluation Study of a Multi-Mode HEV with a Dedicated Hybrid Transmission","authors":"R. Toman, J. Macek","doi":"10.46720/f2020-adm-108","DOIUrl":"https://doi.org/10.46720/f2020-adm-108","url":null,"abstract":"The current legislation requires the increasing levels of vehicle powertrain electrification or hybridization to fulfill the limits of green-house gas emissions. Parallel hybrid electric vehicle (HEV) powertrain topologies are among the frequently used layouts, because of their easy applicability on an existing conventional powertrain by the addition of hybrid modules with mild, full, or plug-in capability. A more “HEV-tailored” approach merges a dedicated hybrid transmission (DHT), an ICE, a gearbox, and one or more electric motors more closely together, reducing HEV powertrain’s mechanical complexity and costs. The current paper investigates a multi-mode HEV with a DHT and two electric machines in optional electric serial or parallel operating modes. Great challenge for the multi-mode HEV topology with DHT is the component sizing: ICE, electric machines, and battery with optimized capacity, and yet fulfilling several roles. On one hand, satisfactory responsiveness on a dynamic driving demands (vehicle acceleration capabilities, top speed etc.). On the other hand, energy consumption achieving better levels than standard parallel HEV topologies. The other challenge for a multi-mode HEV powertrain – similarly as for all HEV powertrains – is a development and optimization of a powertrain supervisory control, based on energy management strategy. These challenges – overall DHT layout, component sizing, and energy management – closely interact and, therefore, must be optimized together. The paper addresses all these challenges using multi-parametric optimization toolchain, that combines a parametric HEV model, energy management strategy, and optimization software. The optimization software includes various optimization strategies: genetic algorithms, gradient based methods, or their combinations. The parametric HEV model is built in GT-Suite 0D/1D/3D multi-physics CAE system simulation software, that also includes different energy management strategies, either locally or globally optimal, considering the whole driving cycle. The toolchain is then used to evaluate the optimal component sizing for two different vehicle classes and fuel economy in a homologation driving cycle and in some real-world driving scenarios. All results are compared to in-house benchmark method.","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"39 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125083392","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}

{"title":"Design and Development Of An In-Wheel Suspension With Novel Automatic Camber Control Strategy For Improved Handling","authors":"S. Shah, Dilip Kumar, Nishant Tiwari","doi":"10.46720/f2020-vdc-081","DOIUrl":"https://doi.org/10.46720/f2020-vdc-081","url":null,"abstract":"In this era of electrification, HEVs are mainly focused on weight and space saving. This is done to ensure the maximum size of the battery package on the vehicle. This situation demands for a drive by wire systems which makes the vehicle lighter as well as more spacious. This paper introduces a new type of In-Wheel suspension has been introduced in this paper. The problem of large suspension systems and its bulkiness were studied. Vehicle instability while driving and cornering was also stated. And the suspension's capability to handle uneven tyre wear which is caused due to improper or fixed camber angle was also addressed. The Novel In-Wheel Suspension is introduced in this paper which houses all the crucial parts of the suspension inside the rim of the wheel thus making it compact, lighter and sturdy. Parts were first designed by the principles of Machine Design, Kinematics and Mechanics of Materials. They were later modelled on Solid Edge ST7. Structural simulations was carried out on FEA Solver under highly strained conditions and also under dynamic loading and the results were satisfactory. A scaled prototype was made by manufacturing the parts on CNC machine. Later the suspension was assembled by brazing the parts together. The Impulse hammer technique was used to carry out the modal analysis which was used to study the damping characteristics of the suspension. Another innovation is introduced in this suspension which the Novel concept of Automatic Camber Control strategy which calibrates the camber angle of the wheel in real-time and greatly improves the performance as well as stability of the vehicle. The design process involved understanding the scaling down the size of the suspension without compensating the functionality of the suspension. The working prototype of the suspension was constructed and after rigorous testing which were carried out. It was found that the performance of suspension under low traction conditions was enhanced.","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128874844","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}

{"title":"Personalized Intelligent Gearshift Schedule Optimization for Electric Vehicles with AMT Considering Multi-performance and Drivetrain Efficiency","authors":"Chao Sun, Y. Lei, Xiaofeng Yin, Kexu Chen, Changhong Dou, Xiaohua Wu","doi":"10.46720/f2020-adm-007","DOIUrl":"https://doi.org/10.46720/f2020-adm-007","url":null,"abstract":"Research and/or Engineering Questions/Objective With the help of automated manual transmission (AMT), the power demand and size of the traction motor of electric vehicles (EVs) could be reduced and such EVs will have more chances to work within the high efficiency area of motor. To further improve the performance and intelligent level of EVs equipped with AMT, the drivability, energy economy and driver’s performance expectation need to be considered together, and meanwhile, the efficiency of the motor and the gearbox should be taken into account. This investigation aims to optimize the gearshift schedule for EVs considering multi-performance, driver’s intention and efficiency of the whole drivetrain. Methodology An efficiency model of the drivetrain including the traction motor and the gearbox is established using neural network, which consists of one sub-efficiency model for the motor, and one sub-efficiency model for each gear. The latter takes the input torque and the input speed of gearbox as input, and the efficiency of gearbox as output. Based on a linear decreasing weight particle swarm optimization (LDWPSO) algorithm, a new gearshift schedule optimization method considering the drivability, energy economy, and driver’s performance expectation, in which the efficiency model of the whole drivetrain is used to calculate the vehicle performance indexes and the efficiency constraint, is put forward. The proposed method is then used to optimize the personalized intelligent multi-performance optimal gearshift schedules for a test EV equipped with AMT. The proposed method and the vehicle performance using the optimized gearshift schedules have also been evaluated via simulation experiments. Results The neural network-based efficiency model of the drivetrain of electric vehicle could build a precise mathematic mapping between the operating conditions and the efficiency of the drivetrain. The optimized gearshift schedule considering multi-performance, driver’s performance expectation and efficiency of drivetrain could make the electric vehicle have better energy economy and driving range and meanwhile maintain good drivability in line with the driver’s intention. Limitations of this study The energy conversion efficiency of the EV battery has not been included in the efficiency model of the drivetrain in this investigation. Further investigation regarding this issue based on battery performance test, will be part of our future work. What does the paper offer that is new in the field including in comparison to other work by the authors? The efficiency model of EV drivetrain including traction motor and gearbox, as well as the proposed optimization method for the personalized intelligent gearshift schedule for EVs equipped with AMT are new. Conclusions A neural network-based efficiency model of EV drivetrain including traction motor and gearbox has been established, and a novel optimization method based on a linear decreasing weight particle swarm op","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"64 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114086622","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}

{"title":"Improvement of the AEB activation algorithm based on the pedestrian reaction","authors":"F. Páez, Ángel Losada, Juan José Herrero","doi":"10.46720/f2021-pif-073","DOIUrl":"https://doi.org/10.46720/f2021-pif-073","url":null,"abstract":"\"This work is an initial activity in the OPREVU project. This project, funded by the Spanish Ministry of Science and Innovation, is aimed at the use of Virtual Reality (VR) and Artificial Intelligence tools to allow the extraction of Vulnerable Road Users (VRU) behaviour patterns in the event of pedestrian collisions, in order to optimize the Autonomous Emergency Braking (AEB) technologies, incorporated in the new generations of commercial vehicles. With the aim of developing and optimizing the current pedestrian identification systems, vehicle tests are performed on INSIA test track with different vehicles to analyse the behaviour of their AEB systems. These systems are equipped with a Lidar and a camera, whose joint operation allows detecting the proximity of the pedestrian and obtaining variables of interest to assess the automatic intervention of the braking system. The tests are inspired by the CPNA50 and CPNA25 tests, carried out by EURONCAP to validate and certify AEB systems. The reference variables are the TTC (Time-to-collision) and the TFCW. FCW (Forward Collision Warning) is a visual and acoustic signal that appears as a warning light or digitally on the instrument panel and warns of the presence of an obstacle in the vehicle's path, and TFCW is calculated from the sum of the driver's average reaction time and the time to stop if the driver applies pressure on the brake pedal until full detection. On the other hand, TTC is the time calculated from the distance and relative speed of the vehicle with respect to the pedestrian. If the TTC is less than TFCW, the system intervenes. By means of the CARSIM© simulation tool (vehicle-pedestrian-road), it is attainable to modify certain boundary parameters, such as the initial conditions of movement of the pedestrian and the vehicle, as well as their initial relative disposition at the beginning of each test. Along these lines, the virtual model incorporates reactions patterns for the pedestrian, such as stopping, running, or changing direction while crossing the road. These reaction patterns are defined by means of VR tests. The CARSIM© vehicle model integrates the fusion of camera and LiDAR data, and an operating algorithm to control the AEB activation. Using Machine Learning techniques, it is feasible to breed vehicle models based on behavioural patterns from the values obtained in the real tests, and to find out the correlation between the corresponding TTC and TFCW values with parameters measured by the calibration equipment, such as: the maximum speed and the time in which it is reached, the initial relative distance and the relative distance at the moment of AEB activation, or the average deceleration from the start of braking, among others. Hence, the data obtained on the INSIA test tracks allow the virtual models to be validated. Furthermore, the novelty of the approach is to consider the pedestrian reactions just before collision, extracted through users’ experiments made in ad-hoc VR","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114430663","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}

{"title":"Various mixture control strategies for a light duty gas engine with scavenged pre-chamber","authors":"Z. Syrovátka, J. Vavra, M. Takáts","doi":"10.46720/f2020-adm-046","DOIUrl":"https://doi.org/10.46720/f2020-adm-046","url":null,"abstract":"This work presents research and development of an advanced ignition system with the scavenged pre-chamber for extremely lean mixture combustion in a natural gas fueled engine for a light duty truck. The goal of the work is efficiency improvement and reduction of greenhouse gas emissions of an engine with a simple and robust after-treatment system, capable to comply with current and future emission limits. The results of experiments show that the scavenged pre-chamber significantly expands the flammability limit compared to the conventional gas fueled SI engine. Low temperature combustion of extremely diluted charge enables to achieve high engine efficiency and low NOx emissions in raw exhaust gases and reduces the necessity of using a special NOx after-treatment. At full load conditions, the pre-chamber engine is able to operate with the stoichiometric mixture to achieve the highest possible power density. The stoichiometric operation is also compatible with a simple three-way catalyst. The proposed control strategy for the pre-chamber engine therefore assumes the use of a combination of stoichiometric operation at high load and lean combustion concept in part and low load region. The paper describes an experimental mapping and optimization in steady state engine operation in selected points of the full performance map with stoichiometric and lean combustion. Tests with activated and de-activated scavenging of the pre-chamber were performed as well. Optimum combustion phasing was considered. Wide range of air excess ratio was investigated to obtain the NOx and combustion efficiency trends for subsequent considerations. Based on the measured results, a detailed engine model was thoroughly calibrated. Transient cycle modelling of proposed fueling control strategy in the World Harmonized Transient Cycle (WHTC) was carried out. Multiple levels of air dilution at low load region were tested and the optimal setting was chosen regarding the combustion efficiency. The results were compared with the conventional SI engine operated with the stoichiometric mixture full time. The results show the operating region where the lean strategy is beneficial in terms of NOx and CO2 emissions. At the current stage, the potential for 5% WHTC CO2 emissions reduction is shown, maintaining NOx emissions level below the current emission limit.","PeriodicalId":174936,"journal":{"name":"FISITA World Congress 2021 - Technical Programme","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127786074","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}