Browse Topic: Throttles

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Development and Validation of Torque Vectoring and Traction Control Strategies in a FSAE Vehicle Using a Dual-Axle Dynamometer HiL Platform2026-01-06444/7/2026
This study presents the vehicle control optimization of a Formula SAE (FSAE) electric vehicle developed by National Taiwan University Racing Team (NTU Racing), utilizing a dual-axle dynamometer and a real-time Hardware-in-the-Loop platform from Chroma. The novelty of this work lies in the comprehensive system-level validation of independent torque control strategies, namely Torque Vectoring (TV) and Traction Control (TC), implemented directly within the vehicle control unit (VCU), and the high-fidelity simulation of dynamic driving scenarios based on the FSAE circuit. The vehicle features an independently controlled rear-axle, two-wheel drive (2WD) configuration, consisting of two in-wheel motors, self-developed inverters, and planetary gearboxes. During testing, a pre-built CarSim driver model provides throttle, brake, and steering inputs to the VCU via Controller Area Network (CAN) interface. The VCU, in turn, computes the independent torque commands according to the TV and TC strategies, which are then transmitted to the inverters and applied to the motors. The resulting torque output from the planetary gearboxes is measured and fed back into the CarSim vehicle model to simulate the rear wheel dynamics and command the dynamometers at the corresponding rotational speeds. The results show that with the dual-axle platform, the independent torque control strategies could be tuned effectively to improve vehicle dynamics, offering a more quantitative and precise approach for performance optimization compared to conventional Model-in-the-Loop (MiL) evaluations or driver-dependent feedback from track testing.
Hsiao, Tsung-Yu, Chen, Zhi-Ren, Jian, Rong-Wei, Chen, Tai-Hsiang, Wang, Tai-Jie, Hu, Wei-Zhe, Ho, Hui-Ting, Wu, Ting-Yu, Lin, Ting-He, Chiu, Joseph
Experimental Validation of a Multi-Row Tapered Roller Bearing Analytical Model for Relating Preload to Frequency Response Characteristics2026-01-00084/7/2026
Roller bearings are used in many rotating power transmission systems in the automotive industry. During the assembly process of the power transmission system, some types of roller bearings (e.g., tapered roller bearings) require a compressive preload force. Those bearings' rolling resistance and lifespan strongly depend on the preload set during the installation process. Therefore, accurate setting of the preload can improve bearing efficiency, increase bearing lifespan and reduce maintenance costs over the life of the vehicle. A new method for bearing preload measurement has shown potential for both high accuracy and fast cycle time using the frequency response characteristics of the power transmission system. An open problem is experimental validation of the multi-row tapered roller bearing analytical model. After validation, the analytical model can be used to predict the assembled system damped natural frequency for a desired bearing preload. This work presents the experimental validation of the analytical model including the experimental test stand, test method, test results and comparison to analytical model. The developed test stand represents an automotive pinion shaft/gear as might be found in a rear axle and can be mounted either vertically or horizontally to simulate assembly and operational positions of the axle and to consider the effects of gravity. To measure bearing preload, the test stand is instrumented with a load cell, and each shaft has strain gages installed. Multiple accelerators are used to measure the system frequency response to an impulse provided by a modal hammer. For this work, three different bearing pairs in back-to-back configuration are tested at seven different preload values. The analytical model is evaluated using the same bearing designs and the preloads measured from the test stand. Results from the analytical model are compared to experimental results to validate the analytical model.
Gruzwalski, David, Mynderse, James
A Proposed Methodology for Human Operator Modeling and Development of a Virtual Operator Model for Control of a Simulated Compact Track Loader2026-01-01464/7/2026
A methodology for performing Human Operator Modeling (HOM) using a Caterpillar Model 299D3 XE Compact Track Loader (CTL) is presented. The proposed method uses task analysis techniques to decompose material excavation and moving tasks into smaller, individual tasks presented in a task list. A method for verifying and refining the task list is presented, along with a procedure for identifying relevant human operator sensory information and analyzing human decision making in the context of CTL operation. This methodology is then partially verified through the analysis of a non-expert human operator in Vortex Studio, a realistic construction equipment simulator. A modified test course is executed by a non-expert human operator in the simulation environment, and the recorded data is used to create a quantitative Human Operator Model. From this, a Virtual Operator Model (VOM) feedback controller simulating the performance of the human operator is developed. The VOM is implemented using a state machine to transition between individual tasks. Fuzzy Logic Control (FLC), is implemented for each task to control bucket tilt, arm lift, and throttle, with controller parameters calculated from the quantitative HOM data. The VOM controller is verified using the same test course performed by the human operator. The performance of the human operator is compared to that of the VOM controller in order to validate the HOM and VOM methodology for a simulation environment.
Wang, Orson R., Norris, William R., Patterson, Albert E., Soylemezoglu, Ahmet, Nottage, Dustin S.
Effect of Pre-Chamber Geometry on Methanol Cold-Start Combustion in an SI Engine2026-01-03074/7/2026
Vehicle pollutant emissions are a major challenge in the development of internal combustion engines. To meet increasingly strict regulations, the automotive sector is exploring alternative fuels and lean-burn strategies. Methanol is gaining importance as a carbon-neutral fuel due to advances in green production technologies. Methanol, despite its potential for renewable production, faces severe limitations due to its inherent poor cold-start performance with conventional ignition systems. In this context, the present study aims to investigate the influence of pre-chamber ignition on cold-start combustion by using high-speed optical diagnostics to visualize flame propagation while simultaneously measuring in-cylinder pressure and engine performance. A major result concerns the significant cyclic variability of conventional spark ignition (SI) under cold-start conditions, which exhibits significant cyclic variability. Instead, passive pre-chamber ignition significantly enhances cold-start combustion stability, lowering CoV IMEP to below 3% at λ = 1.0 and sustaining stability under 5% even in ultra-lean conditions (λ = 1.6), where conventional SI operation fails. Flame visualization quantitatively confirms that this stability stems from distributed, multi-point ignition, which accelerates initial flame propagation by 3-4x compared to SI. These findings demonstrate that pre-chamber ignition can effectively overcome the traditional "cold-start" problem for methanol, enabling stable combustion from the first cycles. This provides an invaluable dataset for CFD model validation, as it captures a highly stable combustion process largely independent of the adverse thermal boundary conditions typical of cold start, thereby simplifying the modeling challenge.
Sementa, Paolo, Altieri, Nunzio, Tornatore, Cinzia
Control Strategy and Dynamic Characteristics of a Hydrogen Opposed-Cylinder Free-Piston Engine Generator2026-01-50172/23/2026
Free-piston engine generator (FPEG), as a novel energy conversion device, has the advantages of good fuel adaptability and high energy utilization. Combustion variation between cycles poses a significant challenge to the running control of an FPEG. A hierarchical control strategy, including motion, combustion, and generation power controllers, is designed in this paper to achieve the stable and efficient running of a hydrogen-fueled opposed-cylinder FPEG prototype. Piston motion is controlled by adjusting the generation current, which is adjusted through iterative learning using piston displacement feedback and adaptive control using piston velocity feedback. Generating power is regulated by controlling the throttle opening angle, which is adjusted through iterative learning. A multidisciplinary joint mathematical model is developed to simulate the dynamic characteristics and verify the control strategy. The simulation results reveals that the dead center position accuracy can be maintained within ±0.3 mm when accounting for 25% combustion variation between cycles and misfires. The power generation can be adjusted between 20 kW and 30 kW, with the adjustment error maintained within ±0.3 kW. The prototype achieved an indicated power of 30.5 kW and an indicated thermal efficiency of 43.4% during the standard cycle. Hardware-in-the-loop testing was conducted for cold start, stable operation, and misfire conditions, confirming that the electronic controller meets the control requirements of the FPEG system.
Wang, Jiesheng, Liu, Liang, Xu, Zhaoping
Real time Implementation of Predictive Maintenance for Service Center Automation Using Automobile Life Extender (ALE) Based on Machine Learning2026-28-01242/12/2026
The Automobile Life Extender (ALE) comprises an on-board function, a machine learning model operating via cloud computing and a smartphone app. The on-board function receives signals such as engine RPM, throttle position, brake pedal position, and hydraulic pressure from the vehicle's ECUs. Based on this data, the on-board ALE module calculates the engine load, brake circuit load, etc., and sends it to the predictive maintenance model via the on-board IoT system. The predictive maintenance model contains recorded data about the type of engine, brake system, and their performance curves acquired from tests conducted by its OEM. Machine learning models holds a crucial role in dynamically analyzing vehicle data, identifying drive patterns, and predicting the need for maintenance of a part or system. A hybrid approach of training models based on supervised and unsupervised learning is incorporated, creating an active learning strategy to maximize the use of available data. Amazon SageMaker handles training the ML models, which can be fed into the Amazon Bedrock cloud agent as a customized model. The Amazon Bedrock code interpretation feature assists in visualizing the machine learning model. The model predicts whether repair, replacement, or maintenance is needed. The results from the ML model are displayed to the driver via a smartphone app. Based on the owner's approval, the service center can access the results from the cloud to perform diagnostics even before the vehicle reaches the service station and allocate servicing slots based on their current workload, spare parts availability, and the vehicle owner's schedule. The modular design approach is applied to accommodate other vehicle types, with provisions for model retraining based on new data.
Sundaram, Rameshselvakumar, Kumar, Lokesh, Saint Peter Thomas, Edwin, Sureshkumar, Srihari, Muthukumaran, Chockalingam, Menon, Abhijith
Performance Evaluation and Optimization of Engine Brake System using Chassis Dynamometer2026-26-05111/16/2026
Engine braking is a deceleration technique that leverages the internal friction and pumping losses within the engine. By closing the throttle and potentially selecting a lower gear, the engine creates a retarding force that slows the vehicle. This practice contributes to better fuel economy, decreased brake system load, and improved vehicle handling in specific driving scenarios, such as steep declines or slippery road surfaces. To alleviate stress on their primary braking systems and prevent overheating, heavy vehicles frequently incorporate engine-based braking. While older trucks relied on simple exhaust brakes with a butterfly valve to restrict exhaust flow, these had limited impact. Hence contemporary heavy vehicles almost exclusively use more advanced engine braking technologies. Traditionally, our heavy-duty vehicles use Exhaust brake system to elevate the braking performance on hilly terrains. Hence an improved sample of Engine brake was developed for enhanced braking performance. A study to map the performance of Engine braking at different field conditions was conducted at Chassis Dynamometer Lab on M&HCV Tipper Vehicle model. Conditions are: a) Different speeds/gears. b) Different gradients. Vehicle fitted with improved sample of Exhaust brake is tested on Chassis dyno for its performance. Braking power derived & plotted at various Engine speeds and compared with the performance results of existing Engine brake sample. Iterations carried out using various gears at different levels of gradient to simulate real world performance of Engine braking and tested the capabilities of the brake sample to the extreme levels of over speeding engine revolutions. The results obtained from this exercise fortified in evaluating and optimizing the improved sample of exhaust brake and it in turn aided in better performance of the vehicle on road.
M, Vipin Prakash, Rajappan, Dinesh Kumar, R, Suresh, N, Gopi Kannan
Optimization of Propeller Shaft Design to Eliminate Launch Undulation (Lateral Shake) and Vibration Level2026-26-03341/16/2026
During vehicle launches in 1st gear, a lateral shake (undulation) and a pronounced metallic hitting noise were observed in the underbody. The noise was identified as the propeller shaft's second universal joint (UJ) yoke striking the fuel tank mounting bracket. Sensitivity to these issues varied with acceleration inputs: light pedal input during a normal 1st gear launch on a flat road resulted in minimal undulation, whereas wide open throttle (WOT) conditions in 1st gear produced significant lateral shake and intensified hitting noise. Further investigation revealed that the problem persists across all gears and occurs consistently during normal driving conditions, with continuous impact between the propeller shaft yoke and the fuel tank mounting bracket. Extensive experimental measurements at the vehicle level indicated that these issues were primarily caused by the center-mounted propeller shaft joint deviating from its central position and rotating eccentrically under torque. This eccentric movement was linked to the improper propeller shaft split ratio and shorter fitting length. A detailed design study combined with vehicle-level experiments (Design of Experiments, DOE) confirmed that these factors significantly contribute to the positional shift of the second UJ connection and its resulting eccentric behavior. This study provides a comprehensive approach to addressing the issue, focusing on reducing vibrations transmitted to the floor and seats and give NVH refinement through the propeller design optimization. By doing so, it ensures improved vehicle performance without compromising other critical parameters.
Sanjay, L, S, Manickaraja, Kumar, Sarvesh, Kanagaraj, Pothiraj, Senthil Raja, T, B, Prem Prabhakar, M, Kiran
Experimental Evaluation of Energy and Exergy of Hydrogen, CNG and Gasoline Fuelled High-Speed Spark Ignition Engine2026-26-02581/16/2026
The maximum power is recorded with Gasoline than CNG and Hydrogen fuel. The maximum exergy and energy efficiency is with Hydrogen, followed by CNG and then Gasoline. Hydrogen fuel has a maximum potential to convert into energy. The maximum energy destruction of 48.7kW for gasoline fuel at 3000 rpm and followed by CNG and hydrogen. The maximum entropy generation of 85.5 W/K with Gasoline and 60.72 W/K and 29.39W/K for CNG and hydrogen engine respectively at 10000 rpm. The entropy generation rate increase with engine speed. The highest rate of heat release is from hydrogen fuel, followed by Gasoline and CNG.
Shinde, Apurwa Balasaheb, Kadam, Tushar, karunamurthy, K, SHINDE, DR BALU
Strategic & Frugal Technology Approach to Meet the Stringent CPCB-IV+ Emission Norms2026-26-00591/16/2026
In CPCB-IV+ Emissions regulations NOx & PM are reduced by 90% from CPCB-II limits in the power band 56 < kW ≤ 560. Obvious technology approach adopted by industry to meet this requirement is the introduction of CRDI fuel injection system & DOC+SCR+ASC aftertreatment technology, leading to substantial modifications at both engine & genset level. This result into huge development expenditure, high incremental product cost, timelines and increased total cost of ownership. This paper describes the frugal technology approach to keep development cost, product cost, development time to the minimum using electronically governed, high pressure mechanical fuel injection equipment, with DOC+SCR+ASC without any external thermal management strategy while comfortably achieving target CPCB-IV+ emission levels. This integrated approach also helped in completing the entire development in < 12 months. 1D-thermodynamic & 3D-combustion simulation approach was adopted to predict the engine out emissions and to optimize combustion hardware. This was followed by Virtual Test Bench (VTB) or closed loop HiL system simulation to integrate the engine, after-treatment plant models, actuators, sensors, ECU, ACU, GCU & RMS. In VTB lab, all the corresponding software’s communication was established and most of the NCD functionalities were verified before moving on to the actual test bed activities. The matured dataset from VTB and hardware selected through simulation were further taken up on the engine testbench and engine out calibration. As per the engine out & tailpipe emissions targets and engine out performance conditions, required exhaust aftertreatment was selected through benchmarking, technology potential analysis, which is to be DOC+SCR+ASC and without any external thermal management strategy i.e. intake throttle valve, HC dozer etc. same was taken care by engine out optimization and TC to DOC inlet exhaust gas temperature drop by thermal insulation. Further, DOC+SCR+ASC system was optimized through 1D & 3D CFD simulations for Uniformity index, back pressure, thermal mapping, Urea deposits and SCR conversions prediction etc. After freezing the EATS design, tailpipe/ SCR calibration was carried out. Through this approach CPCB-IV+ emission norms could be met with NOx emissions min. of 50% margin, PM emissions min. of 30% margin. NCD regulations met with single NCD family, while maintaining best in class fuel & DEF consumption levels.
Arde, Vasundhara, Juttu, Simachalam, Kadam, Atit, Gothekar, Sanjeev, Karthick, K, Vandana, Suryanarayana, Thipse, S, Kendre, Mahadev
A CNN–LSTM–SVM Framework for Mapping Driving Styles to Adaptive Suspension Modes10-10-02-00111/9/2026
Personalized suspension control is pivotal for enhancing vehicle dynamics and ride comfort in intelligent driving systems. This study proposes a driver style recognition model integrating convolutional neural network (CNN) and long–short-term memory (LSTM) networks to match suspension modes with driving styles, validated via a MATLAB–Python co-simulation platform. Time-series multi-source sensor data (throttle position, steering angle, braking intensity) are processed by CNN to extract spatiotemporal features and by LSTM to capture long-term temporal dependencies, enabling accurate classification of aggressive, smooth, and conservative driving styles. A support vector machine (SVM) maps these styles to optimal suspension modes—sport, comfort, or economy—forming an end-to-end framework. Simulation results demonstrate that the CNN–LSTM model achieves an 88% classification accuracy, a 17.33% improvement over the genetic algorithm-optimized backpropagation (GA-BP) model. The SVM-based matching yields matching degrees of 0.95, 0.90, and 0.88 for the three styles, respectively, confirming high accuracy and robustness. Compared to baseline models, the proposed approach excels in prediction accuracy, convergence speed, computational efficiency, generalization, and stability. These findings offer a robust solution for personalized suspension control, enhancing vehicle dynamics and driver comfort.
Wang, Zhuang, Liu, Jiang, Sun, Haoyu, Yuan, Yinghao, Liu, Jianze, Chen, Xiaofei, Wang, Honglin
Research on the Evaluation of the Anti - Misuse System for Passenger Vehicle Accelerator Pedals2025-99-022912/23/2025
In recent years, the number of traffic accidents caused by the misuse of the accelerator pedal in China has been on the rise. To mitigate this issue and enhance road safety, an increasing number of vehicles are being equipped with anti - misuse systems for accelerator pedals. This paper comprehensively analyzes the composition and fundamental technical principles of the current mainstream anti - misuse systems for accelerator pedals, and derives the key aspects of system utilization from the perspective of driver - side operation. Subsequently, the Analytic Hierarchy Process (AHP) is employed to identify relevant evaluation indicators and assign appropriate weights. Based on these findings, a novel test and evaluation framework for such systems is proposed. Finally, real - world vehicle tests are conducted to validate the proposed framework. The results demonstrate that this evaluation system is capable of quantitatively assessing both system performance and human - machine interaction, thus providing a solid foundation for the optimization of anti - misuse systems for accelerator pedals.
Wang, Zhiyu, Zhang, Shan
Combustion Chamber Geometry Comparison in Natural Gas Engines under Conventional and Dethrottled Operation2025-36-021712/18/2025
Growing interest in cleaner energy has spurred progress in engine technology, focusing on greater efficiency and lower emissions. Methane-based fuels, like compressed natural gas (CNG), have become an alternative for spark-ignition engines, especially in Brazil. Among performance strategies, dethrottled operation stands out by reducing intake restrictions and minimizing pumping losses, a major inefficiency in conventional spark ignition engines. This improves thermal efficiency and reduces both fuel consumption and emissions. This study experimentally examines the performance and combustion of a CNG-powered Hyundai HR 2.5 16V engine, converted from diesel to spark ignition with natural gas, comparing factory (omega) and custom (reentrant) piston geometries under both conventional and dethrottled modes. The research evaluates how piston design affects combustion stability, efficiency, and emissions across different load strategies. Tests were conducted at 7, 8, and 9 bar loads, as well as full load, with engine speed at 1800 rpm. In conventional mode, load was controlled by the throttle at stoichiometric conditions (λ = 1); in dethrottled mode, the throttle was fully open, and load was controlled by mixture enleanment (λ > 1). The reentrant piston was designed to intensify turbulence at ignition, supporting faster flame propagation and combustion stability for methane fuels, especially under lean conditions. Results showed that the custom piston consistently delivered lower COVimep, shorter combustion durations, and higher thermal efficiency compared to the factory geometry. Dethrottled operation significantly reduced specific fuel consumption at low loads and improved indicated efficiency, despite increased THC. These effects were mitigated in part by improved combustion quality from the custom piston. Overall, the combination of dethrottling and optimized piston design offers a promising approach to improving the performance of natural gas engines operating under partial-load conditions.
Silva, Cristian Douglas Rosa da, Garlet, Roberto Antonio, Dapper, Jackson Mayer, Fagundez, Jean Lucca Souza, Lanzanova, Thompson Diórdinis Metzka, Martins, Mario Eduardo Santos
Meet SMSPDs: Superconducting Microwire Single-Photon DetectorsTBMG-5391510/1/2025
To learn more about the nature of matter, energy, space, and time, physicists smash high-energy particles together in large accelerator machines, creating sprays of millions of particles per second of a variety of masses and speeds. The collisions may also produce entirely new particles not predicted by the standard model, the prevailing theory of fundamental particles and forces in our universe. Plans are underway to create more powerful particle accelerators, whose collisions will unleash even larger subatomic storms. How will researchers sift through the chaos?
Integrated CFD-Experimental Methodology for Hydrogen-Fuelled Small Loop Scavenged Two-Stroke Engines2025-24-00149/7/2025
This paper presents an integrated methodology for the analysis of hydrogen-fueled 2-Stroke engines, combining experimental data, 1D-CFD simulations, and 3D-CFD combustion calculations. The proposed approach aims to enhance the understanding of scavenging, injection, and combustion processes in a 50 cm3 loop-scavenged engine with low-pressure direct hydrogen injection, experimentally studied on a test bench. The hydrogen-fueled engine was capable of achieving a maximum power output of 3.1 kW, using a slightly lean air-to-fuel ratio (lambda = 1.3). The maximum engine speed for stable combustion without knocking was achieved at wide open throttle at 7119 RPM. The developed 1D-CFD model, based on the engine layout at the test bench, was calibrated using average experimental data and specific full load operating points. 3D-CFD simulations were performed for one full load operating point, focusing on combustion dynamics and fuel distribution within the chamber, with combustion model parameters calibrated to ensure consistency with experimental data. The integrated approach resulted in a good agreement between numerical results and experimental data. The proposed methodology enables accurate model calibration and a deeper understanding of complex physical phenomena, representing a valuable tool for the development of low emission engines.
Caprioli, Stefano, Ferretti, Luca, Scrignoli, Francesco, Fiaschi, Matteo, D'Elia, Matteo, Oswald, Roland, Schoegl, Oliver, Nambully, Suresh Kumar, Rothbauer, Rainer, Mattarelli, Enrico, Kirchberger, Roland, Rinaldini, Carlo
Smart Ignition Coil for H2 ICE Application with Combustion Diagnostic System for Misfire Detection2025-24-00589/7/2025
The transition to decarbonized transportation necessitates significant modifications to internal combustion engines for alternative carbon-neutral fuels, particularly hydrogen. The integration of alternative systems is crucial for improving engine control, facilitating real-time engine health monitoring and facilitate early problem detection. This study investigates the potentialities of an ignition system specifically designed for H2 applications, with the integration of a smart coil diagnostic system with the aim to enhance engine performance and control capabilities. Experiments were conducted on a single-cylinder research engine across varying spark advanced, throttle positions, and engine speeds, comparing the novel ignition system with integrated diagnostics against traditional spark plug. Results demonstrate improvements in combustion stability and control when innovative spark plug was employed. Compared to a conventional spark plug, the Hy2Fire® system consistently delivered superior performance, achieving a peak indicated mean effective pressure (IMEP) of 4.85 bar (vs 4.68 bar) and maintaining a coefficient of variance of IMEP (CoVIMEP) below 2% across a broad range of conditions. The system demonstrated earlier combustion phasing (AI50 reduced by over 1 CAD) and improved combustion stability, especially under lean-burn (λ = 2.0) scenarios. Analyzing diagnostic signals from the smart coil's secondary spark current offers a promising avenue for evaluating combustion quality and its relationship to in-cylinder pressure, thus representing significant advancements. A dual-method approach, employing artificial intelligence algorithms for signal processing, enabled precise identification of maximum in-cylinder pressure with an error below 10%, and detection of anomalies such as misfire events. This analysis facilitated the precise identification of in-cylinder maximum pressure, a crucial parameter for engine performance evaluation, and the detection of critical anomalies such as misfire, which can severely impact engine longevity and efficiency. The system's behavior under the varying operating conditions tested has been thoroughly analyzed, highlighting its robustness and adaptability.
Ricci, Federico, Papi, Stefano, Avana, Massimiliano, Dal Re, Massimo, Grimaldi, Carlo
Method for Externally Controlled Availability of Lubricating Oil in Internal Combustion Engines2025-01-03027/2/2025
Reduced raw emissions from internal combustion engines (ICE) are a key requirement to reach future green-house-gas and pollutive emissions regulations. In parallel, to satisfy the need for increased engine efficiencies, the friction losses of ICEs gains attention. Measures to reduce parasitic drag inside the piston assembly such as reduced piston-ring pretension or thinner grade engine oils may increase oil ingress into the combustion chamber. The oil ingress is known to imply increased particle emissions directly counteracting the raw emission reduction target of engine development. To resolve this target conflict, the transport mechanisms of oil into the combustion chamber are the topic of current research. Specially developed research engines featuring a vertical optical window come with big potential to visualize the phenomena of the oil behavior inside the piston assembly group. Such ‘glass-liner’ engines play a pivotal role in identification and quantification of local and global phenomena and their correlating operating parameters. The objective of this study is to develop and investigate a novel approach facilitating active control over the amount of oil available in the piston group assembly under varying operating parameters. The mechanical incorporation into the engine relies on ports embedded into the cylinder wall. These ports facilitate accessing the ring-land areas to realize fluid flow out of the piston group assembly using either vacuum or compressed air. The system is investigated in both a ‘glass-liner’ as well as a thermodynamic engine. Optically, the amount of oil present at the piston surface as well as residual oil on the cylinder wall is evaluated. A reduction of up to 40 percent of the indicated LIF-intensity from the residual oil on the cylinder surface can be shown. Similar results from tailpipe measurements are also demonstrated.
Stark, Michael, Fellner, Felix, Härtl, Martin, Jaensch, Malte
Robotic System for Infrastructure ReconnaissanceTBMG-532306/1/2025
Innovators at NASA Johnson Space Center have developed a robotic system whose primary structural platform, or “orb,” can be injected into a pipe network and perform reconnaissance of piping infrastructure and other interior volumes. When deployed, this technology uses throttled fluid flow from a companion device for passive propulsion. A tethered line facilitates directional control by the orb’s operator, allowing it to navigate through various piping configurations, including 90° junctions.
Experimental Study for Energy Balance and Exergy Analysis of a Single-Cylinder, Spark-Ignition, Air-Cooled Engine03-18-04-00235/22/2025
In a time when small and micro energy sources are becoming increasingly important due to current environmental challenges, the efficient recovery of low-grade waste heat has emerged as a key strategy to enhance overall energy sustainability. Although extensive research has been conducted on energy and exergy distributions in large-scale internal combustion engines, experimental studies focusing on small, air-cooled gasoline engines remain limited, particularly regarding the quantification of their recoverable energy potential. Addressing this gap, this work analyzes and quantifies the global energy distribution and exergy availability in a single-cylinder, spark-ignition, air-cooled Robin EY15 engine operating at rotational speeds between 1500 and 4600 min−1, and throttle valve openings from one-quarter to full. The defined control volume includes the engine and the load system. The mass flows analyzed are fuel flow (standard gasoline), intake air, exhaust gas (assumed as air) and cooling air, while the energy flows are net power and miscellaneous heat losses. It is found that the maximum net and exergy efficiencies of the engine are 14.1% and 13%, respectively, at 2500 min−1 and full open throttle. The major energy dissipation ways are the cooling air 24.3%–73.6% and miscellaneous losses 9%–61% (percentage related to total energy flow provided by the fuel). Based on exergy analysis, between 6%–9.7% and 22%–29.7%, respectively, of that energy flows are transformable into mechanical work; however, the exhaust gases has the higher potential, between 22.7% and 34.7%. The rate of exergy destroyed ranges between 69.6% and 89.7%, meaning that the maximum achievable efficiency would range from 10.3% up to 30.5% throughout the tested engine speed–load conditions. These findings provide useful insights into the low-grade heat recovery potential of small-scale combustion engines and contribute new experimental data to the field of micro energy systems.
Romero, Carlos Alberto, Monroy, Mauricio, Ramírez, Juan David
Optimization of HEV Vehicle’s Engine Modulated Noise2025-01-00845/5/2025
One 1.5L Miller-cycle turbocharged four cylinder gasoline hybrid engine is installed on a certain hybrid vehicle. When accelerating at low to medium speeds with a small throttle, there is a "da da" knocking noise inside the car, which seriously affects the overall sound quality of the vehicle. By analyzing the vibration and noise data of the engine, it was found that the frequency of the abnormal knocking sound is 200-2000Hz, which presents a half order characteristic in the time domain, that is, one knocking occurs when the engine crankshaft rotates twice. Through Hilbert demodulation analysis of the vibration data in the problem frequency range, it was found that the knocking noise was modulated in the frequency domain, with a modulation frequency of half of the crankshaft rotation frequency. By building a fully flexible multi-body dynamic model of a hybrid powertrain and inputting the engine's cylinder pressure excitation, the combustion excitation is coupled with mechanical vibration noise to simulate the surface vibration of the powertrain. Measures such as optimizing the cylinder pressure curve by adjusting spark angle and scavenging angle, and improving crankshaft stiffness by increasing the overlap between mainbearing diameter and connecting rod diameter, the sound quality issue of this hybrid model has been significantly improved under low speed and low throttle acceleration conditions.
Dan, Kong
New System for Turning Seawater into Hydrogen FuelTBMG-530435/1/2025
Researchers at the DoE’s SLAC National Accelerator Laboratory and Stanford University with collaborators at the University of Oregon and Manchester Metropolitan University have found a way to tease hydrogen out of the ocean by funneling seawater through a double-membrane system and electricity. The design successfully generated hydrogen gas without producing large amounts of harmful byproducts. The results, published in Joule, could help advance efforts to produce low-carbon fuels.
Enhancements in Hydrogen Low Pressure Injection on Small Two-Stroke Engines2024-32-00474/18/2025
The use of small 2-stroke crankcase scavenged engines running on hydrogen is very attractive for low power rates, when low cost and compact dimensions are the fundamental design constraints. However, achieving optimal performance with hydrogen fuel presents challenges, including uneven air-fuel mixtures, fuel losses, and crankcase backfiring. This research focuses on a small 50cc 2-stroke loop-scavenged engine equipped with a patented Low-Pressure Direct Injection (LPDI) system, modified for hydrogen use. Experimental results demonstrate performance comparable to the gasoline counterpart, but further optimizations are needed. Consequently, CFD-3D simulations are employed to analyses the injection process and guide engine development. The numerical analysis focuses on a fixed operating condition: 6000 rpm, Wide Open Throttle (WOT), with a slightly lean mixture and injection pressure fixed at 5 bar. A numerical model of the entire engine is set up with the primary objective of improving injection efficiency by modifying the position and orientation of the injector, along with the piston dome shape. Seven configurations under the same operating conditions and injected mass are investigated to assess the impact of these modifications and find the best compromise. The methodology considers the following parameters: fuel trapped within the cylinder, fuel lost through the exhaust, fuel mass in the crankcase, and mixture uniformity before spark ignition. The best-performing configuration, featuring a standard piston dome but with a repositioned injector, achieves a notable reduction in fuel short-circuiting (up to 20%), while ensuring a relatively uniform air-fuel mixture at spark timing.
Caprioli, Stefano, Schoegl, Oliver, Oswald, Roland, Kirchberger, Roland, Mattarelli, Enrico, Rinaldini, Carlo Alberto
Development of Cylinder Deactivation Control during Idle for Conventional Engines2024-32-00194/18/2025
This report examines the advancement and utilization of cylinder deactivation technology that enhances fuel efficiency in conventional engines without hardware modifications. It operates by halting fuel supply to some of the cylinders in multi-cylinder engines and increasing the output power of the remaining active cylinders to maintain an idle state. By implementing this technology in the mass-produced 90° V-twin engine, the U502, and deactivating one of its two cylinders, fuel consumption during idling is reduced by over 30%. The focus of this study is on the technology developed to minimize engine speed fluctuations during the transition to cylinder deactivation and reactivation for the engine. By making various modifications to the fuel injection control sequence and optimizing the throttle opening of each cylinder in idle and driving conditions, engine speed fluctuations were minimized. This allows users to reduce fuel consumption while maintaining the engine’s original performance, with the transition in cylinder deactivation being virtually imperceptible.
YANAGIDA, Shoji
Development and Control System Design of an Electro-Pneumatic Variable Valve Actuator to Be Retrofitted to an SI Engine2025-01-83774/1/2025
In a conventional cam-based valve actuation system, the valve events are tied up with the rotation of the crankshaft. In contrast, the electronic variable valve actuation (VVA) system enables flexible control of valve events independent of the crankshaft rotation. The present article discusses the development and control system design of a single-acting electro-pneumatic variable valve actuation (EPVVA) system that can be retrofitted to a conventional SI engine. The EPVVA system utilizes fast switching solenoid valves which modulate the flow of pressurized air in and out of a pneumatic chamber. The control system design is conducted in MATLAB Simulink platform using model-based approach. The valve actuator model is formulated such that it simulates the trajectory of the motion of the engine valve by numerically integrating a set of coupled differential equations that govern the thermo-fluid-dynamics and applied mechanics aspects of the valve actuation of the EPVVA system. The timings of the valve actuation events are synchronized with the required timings derived from the operation of an engine valve-train model that runs in tandem with the valve-actuator model. The durations of the electrical pulses sent to the various solenoid valves are controlled to achieve the desirable valve lift profile. The delays in valve actuation are determined in closed loops and are compensated in the next cycle by adjusting the switching-on and switching-off instants of the electrical pulses. The control of the load without a throttle valve is achieved by appropriately altering the area under the valve lift profile. The good correspondence between the predictions of the mathematical theory and the experimentally measured valve lift profiles shows that the desired control of valve events and load can be achieved across a wide range of engine speeds with the help of the EPVVA system.
Satalagaon, Ajay Kumar, Guha, Abhijit, Srivastava, Dhananjay Kumar
Research on Pedal Operation Characteristics for Detecting Pedal Misapplication2025-01-86754/1/2025
Drivers sometimes operate the accelerator pedal instead of the brake pedal due to driver error, which can potentially result in serious accidents. To address this, the Acceleration Control for Pedal Error (ACPE) system has been developed. This system detects such errors and controls vehicle acceleration to prevent these incidents. The United Nations is already considering regulations for this technology. This ACPE system is designed to operate at low speeds, from vehicle standstill to creep driving. However, if the system can detect errors based on the driver's operation of the accelerator pedal at various driving speeds, the system will be even more effective in terms of safety. The activation threshold of ACPE is designed to detect operational errors, and it is necessary to prevent the system from being activated during operational operations other than operational errors, i.e., false activation. This study focuses on the pedal operation characteristics of pedal stroke speed and pedal force speed, which used as the threshold for activation of ACPE. It examines the detection of pedal misapplication based on the operation characteristics of the accelerator and brake pedals during normal driving, with a particular emphasis on preventing false activations. We hypothesize that if there is a significant difference in the operations of the accelerator pedal and brake pedals while driving, it can be used as a threshold for judging misstep. In this study, we utilized a driving simulator to conduct driving experiments that simulated urban and highway environments. This allowed us to collect data on drivers' operations of the accelerator and brake pedals, including metrics such as pedal stroke speed and pedal force speed. The experimental scenario involved the driver following a car ahead that repeatedly accelerated and decelerated in both urban and highway areas. The results of the analysis of the pedal stroke speed and the pedal force speed showed that the brake pedal was operated faster than the accelerator pedal, with a significant difference confirmed. In addition, to prevent false activation and to improve the accuracy of detecting pedal misapplication, it is considered effective to incorporate factors such as relative velocity and ego vehicle speed into the activation thresholds, potentially set through machine learning or other methods.
Natsume, Hayato, Shen, Shuncong, Hirose, Toshiya
An Overview and Testing of Pedal Misapplication Systems2025-01-87054/1/2025
Performance testing was conducted to assess the effectiveness of five different pedal misapplication mitigation (PMM) systems in a simulated PMM scenario. These systems are components of advanced driver-assistance systems (ADAS), which are designed to detect and mitigate inadvertent sudden accelerator pedal misapplications by drivers. A 2023 BMW iX, 2020 Tesla Model 3, 2014 Subaru Forester, 2020 Subaru Outback, and a 2023 Subaru Ascent were tested in a simulated pedal misapplication scenario, whereby the test vehicle's accelerator was quickly depressed with a stationary pedestrian and vehicle target in front of the test vehicle. The testing involved measuring the performance of the respective vehicles' pedal misapplication mitigation systems, including when or if engine/motor output or throttle was limited or reduced, whether a forward collision warning was provided, or if the vehicle automatically engaged braking and/or braked to a stop before contact with the soft targets. Results of the five vehicles tested will be presented and compared.
Harrington, Shawn, Takbhate, Shubham Ramraja, Martin, Nicholas, Patrick-Moline, Peyton, Handzic, Dino
Active Unmatched Disturbance Rejection Quasi-Sliding Observer for Electronic Throttle Valve System Based on Backstepping Control03-18-02-00112/10/2025
This study addresses the control problem of the electronic throttle valve (ETV) system in the presence of unmatched perturbations. Most previous works have ignored the effect of actuating motor inductance, which results in an approximated model with a matched perturbation structure. However, if this assumption is not permitted, the ETV model turns into an exact model with unmatched perturbation and the control task becomes more challenging. In this article, a backstepping control design based on a quasi-sliding mode disturbance observer (BS-QSMDO) has been proposed to effectively reject the unmatched perturbation in the ETV system. A rigorous stability analysis has been conducted to prove the ultimate boundedness for disturbance estimation error and tracking error. The key to this proposed observer-based control design is to obtain a robust and chattering-free controller based on a quasi-sliding mode methodology. The proposed quasi-sliding mode observer works to estimate the unmatched perturbation to be then actively rejected by the backstepping controller. Moreover, the observer adds a boundary layer around the sliding manifold to confine the estimation errors within a non-zero layer at the sliding phase, which leads to a considerable reduction of the chattering effect. A comparison study of the proposed BS-QSMDO is made with another backstepping controller based on a nonlinear disturbance observer (BS-NLDO). The numerical results showed the superiority of BS-QSMDO over BS-NLDO in terms of the ultimate bound of estimation and tracking errors. The numerical results showed that the BS-QSMDO could improve the tracking position error, control effort, and estimation errors of unmatched uncertainty by percentages of 26.67%, 1.46% and 92.5%, respectively, as compared to BS-NLDO.
Hameed, Akram Hashim, Al-Samarraie, Shibly Ahmed, Humaidi, Amjad Jaleel
FPGA Implementation of HLS Crypto Accelerators for Embedded Security in Autonomous Vehicles2025-28-02052/7/2025
The growing ubiquity of autonomous vehicles (AVs) has introduced a new attack surface for malicious actors: the embedded systems that govern a vehicle's critical operations. Security breaches in these systems could have catastrophic consequences, potentially leading to loss of control, manipulation of sensor data, or even physical harm. To mitigate these risks, robust cybersecurity measures are paramount. This research delves into a specific threat – side-channel attacks – where attackers exploit data leakage through unintentional physical emanations, like power consumption or electromagnetic waves, to steal cryptographic keys or sensitive information. While various software and hardware countermeasures have been proposed, this study focuses on the implementation of masking techniques within the realm of embedded security. Masking techniques aim to obfuscate sensitive data during cryptographic operations, making it significantly harder for attackers to exploit side-channel vulnerabilities. This research explores the suitability of a Boolean masking approach within a high-level synthesis environment. This system-level approach offers several advantages over traditional design methodologies. It facilitates faster design processes by enabling early identification and rectification of errors. Additionally, it streamlines hardware-software co-design, allowing for a more integrated and efficient security architecture within the autonomous vehicle's embedded systems. Furthermore, the system-level approach enables the application of advanced validation strategies, ensuring the effectiveness of the implemented masking techniques. To evaluate the efficacy of the Boolean masking approach, the research investigates its application to three prominent block cipher algorithms – PRESENT, AES, and Serpent – all of which are based on substitution-permutation networks (SPNs). By implementing these masked algorithms in C and simulating their performance within an embedded system context, the study assesses factors like resource utilization and overall processing speed. This comparative analysis aims to identify the most effective masking implementation for protecting cryptographic operations in autonomous vehicles. Ultimately, the findings of this research can inform the development of robust security frameworks that safeguard autonomous vehicles against side-channel attacks and other cyber threats, paving the way for a safer and more secure future of transportation.
Deepan Kumar, Sadhasivam, R, Vishnu Ramesh Kumar, M, Boopathi, Manojkumar, R, R, Gobinath, M, Vignesh
Engine Speed Control for the Urban Hybrid-Flex Vehicle2024-36-011812/20/2024
Hybrid Electric Vehicles (HEVs) combine combustion and electric propulsion means to achieve key objectives, such as: reducing fuel consumption, minimizing pollutant emissions, and enhancing the overall energy efficiency of the Powertrain System. The series hybrid electric vehicles, in special, have a topology compound by four Subsystems, which are: Traction, Storage, Energy Generation, and Energy Management. The Energy Generation Subsystem is responsible for the power supply of the electric traction motors and batteries, depending on the control strategy promoted by the Energy Management Subsystem. The Energy Generation Subsystem is essentially made by an Internal Combustion Engine (ICE) and a Generator. Effective control of the power output from the Energy Generation Subsystem necessitates precise regulation of the engine speed. Thus, it is necessary to control the engine speed because this is directly related to the power demand of the consumers of other subsystem components. This study presents a preliminary speed control approach for a four-stroke engine utilized in the Energy Generation Subsystem of a series hybrid-flex vehicle. This work is a component of the larger project “Desenvolvimento de um Veículo Urbano Leve Híbrido Flex (VHF-Urbano)” from the ROTA 2030/MOVER program. To allow the engine speed control, a throttle-by-wire system was designed. Notably, at this stage, the physical system to be controlled is a Single Input and a Single Output (SISO) system, where the desired engine speed is solely achieved by varying the angular position of the throttle valve. A model-based control was developed to achieve the desired engine speed. It is expected to use this first control strategy as a groundwork to develop a more sophisticated strategy, involving other sensors and actuators of the ICE utilized in this work.
Júnior, João Marcos Hilário Barcelos, de Sousa Oliveira, Alessandro Borges, Teixeira, Evandro Leonardo Silva, Pereira, Bruno Luiz, Pinheiro, Leandro Soares, dos Santos Ribeiro, Eduardo, dos Santos de Oliveira, Jordano
Truck Driver Shin-Knee Position for Clutch and AcceleratorJ1521_202412 (Current)12/6/2024
This SAE Recommended Practice describes two-dimensional, 95th percentile truck driver, side view, seated shin-knee contours for both the accelerator operating leg and the clutch operating leg for horizontally adjustable seats (see Figure 1). There is one contour for the clutch shin-knee and one contour for the accelerator shin-knee. There are three locating equations for each curve to accommodate male-to-female ratios of 50:50, 75:25, and 90:10 to 95:5.
Truck and Bus Human Factors Committee
Speed Control Assurance for SnowmobilesJ1222_202412 (Current)12/5/2024
This SAE Standard provides minimum requirements and performance criteria for devices to prevent runaway snowmobiles due to malfunction of the speed control system.
Snowmobile Technical Committee
EDITORIAL: China's warning signs24AUTP12_0412/1/2024
Sometimes, I cringe; sometimes, I just listen and wonder. These past few months have given us all a lot to think about in the automotive space, and it's clear now that the coming years will keep the foot down on the accelerator when it comes to the dramatic changes we've experienced this past decade. One thing that stood out to me in various recent conversations is that there's a widening gulf opening between Chinese automakers and the rest of the world. This isn't exactly news, and this column isn't meant to monger any fears. It's just a bit of off-the-cuff reporting that sheds a bit of light on the level of the challenges we face. As you can read in Chris Clonts' excellent report further in this issue about the warning that Voltaiq's CEO gave at The Battery Show this October, the U.S. is in serious danger of falling well behind Chinese competitors in the EV battery race (Michael Robinette tackles similar ground through a tariff lens in this month's Supplier Eye). But that message was obvious to anyone who meandered through the expo hall during the show. The spacious Huntington Place (neé Cobo Hall) was filled by more battery suppliers and tech companies than I could count (organizers said it was over 1,150), many with a Chinese connection. Those of us who remember the busy days when the Detroit Auto Show covered a similar footprint were astonished by the variety on display, and almost all of it was EV-focused. The Battery Show proved that there's good battery development work happening in North America and Europe, but it was hard to ignore just how present China and Chinese-related companies are in the electrification mission.
Blanco, Sebastian
Experimental Investigation of Energy Consumption in Select Micromobility Vehicles13-06-02-001110/16/2024
This study provides a detailed energy consumption analysis of two popular micromobility vehicles—an e-scooter and an e-bike—under various conditions, including steady-state and dynamics scenarios. Employing a custom-built data acquisition system, the research tested these vehicles in throttle mode, additionally assessing the e-bike across three pedal-assist levels. The findings reveal that the e-bike operates significantly more efficiently than the e-scooter, with both vehicles demonstrating peak power outputs significantly exceeding their rated values. Furthermore, the study explores how cargo affects the e-bike’s energy use, along with the charging and discharging behaviors of both platforms. Notably, the e-scooter exhibited a considerable battery self-depletion rate, a characteristic not observed on the e-bike.
Pamminger, Michael, Duvall, Andrew, Wallner, Thomas
Gas Exchange Optimization for a Passive Pre-Chamber Ignition System2024-24-00349/18/2024
Increasing ignition energy by replacing standard spark igniters with pre-chambers is an established combustion accelerator. With rapid combustion on the one hand, mixture dilution can be extended while maintaining the combustion stability at adequate levels. On the other hand, accelerated combustion reduces the need for knock-induced spark retarding, thus facilitating emission reduction and increases in efficiency simultaneously. A newly developed pre-chamber ignition system is introduced in this work. The influence of the system on combustion is investigated in a single-cylinder research engine. The findings can support the development of future ignition technology for passenger-vehicle-sized engines. There are two basic configurations of pre-chamber igniters: the first is known as passive pre-chamber, the second as scavenged pre-chamber. The first configuration can be realized as a simple replacement for standard spark plugs. While additional costs are minimized, the air-fuel ratio inside the pre-chamber cannot be influenced independently of the main chamber. Consequently, the major challenge for passive pre-chamber igniters is operating in engine map areas suffering from deteriorated pre-chamber gas exchange at low engine load, for example. The second configuration allows precise air-fuel ratio control inside the pre-chamber to circumvent those issues by employing a dedicated pre-chamber injector. However, the overall system cost and complexity increase drastically. Solving these issues is decisive for potential series applications. Geometrical design and adapted valve timing are considered remedies in this publication. As preparation for experimental investigations at a single-cylinder testbench, 3D-CFD simulations were employed to determine promising pre-chamber geometries in the first place. Different pre-chamber geometries have subsequently been investigated with an engine testbench to validate the findings from the simulations. Analysis of the pressure traces in the main and pre-chamber provide insight into the quality of pre-chamber gas exchange and combustion initiation. Adaptive valve actuation strategies supported the pre-chamber gas exchange, consequently leading to optimized engine behavior.
Fellner, Felix, Fitz, Patrick, Härtl, Martin, Jaensch, Malte
Marine Control Cable Connection - Engine Throttle LeverJ961_202409 (Current)9/9/2024
The purpose of this SAE Recommended Practice is to provide guides toward standard conditions for operating marine engine throttles (gasoline or diesel) where push-pull cable control is applicable. For control cable information see SAE J917.
Marine Technical Steering Committee
Motor Control during Gearshift Phase to Reduce the Oscillation in Dual Hybrid Vehicles2024-01-26394/9/2024
This paper defines a control method for shift torque exchange stage and a torque distribution control method for speed regulation stage. In the torque exchange stage, the torque distribution problem of active and passive clutches considers the injection of sine curve for local correction, which can solve the fish belly problem of hydraulic response (i.e. the hydraulic response is slow at the beginning and the hydraulic response is fast at the end). In the speed regulation stage, the target speed gradient profile is determined according to different shift types. The determination of the target speed gradient profile integrates different driving modes, throttle, P2 energy and clutch temperature. In the speed regulation stage, the torque distribution control problem of the speed phase including which actuator (P1, engine, C0 clutch) is used preferentially for speed regulation. a) If the speed regulation torque assigned to the input shaft exceeds the input shaft intervention torque capacity, then the excess part is assigned to the clutch for speed regulation. b) If the speed regulation torque assigned to the input shaft is less than the input shaft intervention torque capacity and the speed regulation torque assigned to the input shaft is less than the motor 2 speed regulation torque intervention capacity, the speed regulation torque is assigned preferentially to P2 for lifting torque. The total P2 request torque for P2 is equal to the sum of the speed regulation torque intervention of P2 and the P2 torque requested by ECM because of the fast response and high precision of the motor. c) If the governing torque assigned to the input shaft is less than the input shaft intervention torque capability and the governing torque assigned to the input shaft is greater than the motor 2 governing torque intervention capability, the excess is assigned to the engine. The total engine requested torque is equal to the sum of the engine governing torque intervention and the engine torque requested by the ECM.
Jing, Junchao, Zhang, Junzhi, Chen, Jialu, Liu, Yiqiang, Huang, Weishan
Study and Analysis on 3-Dimensional Simulation of the Transient Flow Process of Engine Electronic Control Throttle2024-01-24174/9/2024
Based on the basic structure and operation function of engine throttle, according to the actual structure of a throttle, a 3-dimensional simulation of the transient airflow during the rotation of the throttle from the closed position to the fully open position is realized by using CFD together with the moving mesh technology and the user-defined program. The influence of the throttle movement on the airflow process is studied. The velocity field, pressure field, and flow noise field are analyzed at different angles of throttle rotation. The numerical simulation results show that at the beginning period of the throttle rotation, the vortex appears in the flow field behind the throttle, and the drop of the air pressure between the upstream and downstream position of the throttle is sharp. In addition, the results show that the flow noise field appears near the top dead center and bottom dead center of the throttle, and the maximum value of the acoustic power appears when the throttle opening is near 40 degrees. With the increase of the throttle rotation angle, the vortex gradually weakens, the difference of the air pressure between the two sides of the throttle becomes small, the flow noise first increases and then decreases, and the maximum value of the acoustic power appears all the time at the downstream position of the throttle, and its positions are gradually moved away from the axes of the throttle. When the throttle is fully opened, the velocity field, pressure field and flow noise field gradually tend to stabilize.
Yang, Shuai, Ding, Jie, Yan, Kai, Liu, Haifeng, Chen, Yilin
Performance Evaluation of High Octane Gasoline Fuel(s) on High Compression Ratio (HCR) Motorcycle – Based on Chassis Dynamometer Test2024-01-23754/9/2024
The present study aims to determine the comparative performance evaluation in terms of fuel economy (kmpl) and wide open throttle (WOT) power derived from set of different blends of high octane gasoline fuel(s) i.e., Neat Gasoline (E0), E10 & E20 (With different dosages of additives) in high compression ratio (HCR) motorcycle on chassis dynamometer facility. With the Government of India focus on use of alcohol as co-blend of gasoline with the endeavour to save foreign exchange and also to reduce greenhouse gases (GHG) emissions. The commercially available blended fuels, E10 & E20, have high research octane number (RON, 92-100) and as per the available literature high RON fuel have the better anti-knocking tendencies thereby lead to higher fuel economy. There are various routes to formulate high octane fuel (refining technologies, additive approach & ethanol blending route) in the range of 92-100 octane number which are currently commercialized in Indian market. In the present study, ethanol based high octane fuel blend(s) along with doping of novel indigenous type of additives (multifunctional additive & octane booster) to achieve the utilization benefits in terms of fuel economy (FE) & power improvement. The findings of present study largely suggest that with the high octane fuel blends (only ethanol) the fuel economy and Wide Open Throttle (WOT) power reduces. On the other hand, by adding gasoline multi-functional additive (GMFA) in combination of octane booster in the ethanol blended fuels, fuel economy and WOT power are compensated fairly. Fuel economy and Wide Open Throttle (WOT) power were investigated under operating conditions (Indian driving cycle - IDC). On adding ethanol only by 10% and 20% in gasoline the fuel economy is lowered by 1.9% and 4.94% respectively. The loss in fuel economy is reduced by 0.74% and 3.36% through addition of indigenously developed GMFA with Octane Booster in E10 & E20 gasoline blends.
Saroj, Shyamsher, Kalita, Mrinmoy, Kumar, Prashant, Kant, Chander, Patanwal, Pradeep, Chakradhar, Maya, Sithananthan, M, Arora, Ajay Kumar, Harinarain, Ajay Kumar, Maheshwari, Mukul
An Improved AEB Control System Based on Risk Factors with Consideration of Vehicle Stability2024-01-23314/9/2024
Intelligent vehicle-to-everything connectivity is an important development trend in the automotive industry. Among various active safety systems, Autonomous Emergency Braking (AEB) has garnered widespread attention due to its outstanding performance in reducing traffic accidents. AEB effectively avoids or mitigates vehicle collisions through automatic braking, making it a crucial technology in autonomous driving. However, the majority of current AEB safety models exhibit limitations in braking modes and fail to fully consider the overall vehicle stability during braking. To address these issues, this paper proposes an improved AEB control system based on a risk factor (AERF). The upper-level controller introduces the risk factor (RF) and proposes a multi-stage warning/braking control strategy based on preceding vehicle dynamic characteristics, while also calculating the desired acceleration. Furthermore, a lower-level PID-based controller is designed to track the desired acceleration and compute the corresponding brake master cylinder pressure and throttle opening using an established inverse longitudinal dynamics model. Furthermore, to address vehicle stability during braking, an Anti-lock Braking System (ABS) controller is integrated with the proposed AERF. The effectiveness of the AERF is validated through software co-simulation and hardware-in-the-loop testing (HIL). The results demonstrate that the AERF can maintain a safe braking distance within 2 meters under Euro NCAP standard conditions, with excellent tracking performance of the actual braking deceleration and an error rate below 5%, ensuring a high level of system safety.
Guo, Shaozhong, Guo, Jun, Zhang, Yunqing, Wu, Jinglai
Highway Exhaust Emissions of a Natural Gas-Diesel Dual-Fuel Heavy-Duty Truck2024-01-21204/9/2024
Diesel-fueled heavy-duty vehicles (HDVs) can be retrofitted with conversion kits to operate as dual-fuel vehicles in which partial diesel usage is offset by a gaseous fuel such as compressed natural gas (CNG). The main purpose of installing such a conversion kit is to reduce the operating cost of HDVs. Additionally, replacing diesel partially with a low-carbon fuel such as CNG can potentially lead to lower carbon dioxide (CO2) emissions in the tail-pipe. The main issue of CNG-diesel dual-fuel vehicles is the methane (CH4, the primary component of CNG) slip. CH4 is difficult to oxidize in the exhaust after-treatment (EAT) system and its slip may offset the advantage of lower CO2 emissions of natural gas combustion as CH4 is a strong greenhouse gas (GHG). The objective of this study is to compare the emissions of an HDV with a CNG conversion kit operating in diesel and dual-fuel mode during highway operation. Road tests were conducted on a three-axle Class-8 highway semi-trailer tractor hauling a two-axle loaded box trailer. The gross combined weight of the tractor-trailer was 34,470 kg (~76,000 lbs). The tractor was powered by an inline 6-cylinder, direct injection diesel engine with EAT system, and met EPA 2010 emission regulations. The primary components of the conversion kit were: CNG tank, regulator, and mixing manifold with solenoid CNG injectors. CNG was injected into the intake manifold of the engine downstream of the intercooler. The CNG injection map was based on the throttle position, engine speed, load, and intake boost pressure. Portable emissions measurement systems (PEMS) were used to analyze the exhaust gas before and after the EAT system. The vehicle’s onboard diagnostic (OBD) data was also recorded concurrently. The highway test route was 74 km long and the average road speed was ~102 km/h. Results showed that up to 34% of the diesel consumption could be replaced by CNG. When compared to diesel-only, the CO2 and total hydrocarbon emissions of the dual-fuel case were lower and higher, respectively. Engine-out black carbon emissions were lower for the dual-fuel case in comparison to diesel, while tail-pipe nitrogen oxides (NOx) emissions were higher. Distinct differences in the exhaust temperature profiles were observed as well.
Dev, Shouvik, Qi, Aidu, Anderson, Andrew, Dahlseide, Austin, Smith, Brett, Lussier, Simon-Alexandre, Guo, Hongsheng, Rosenblatt, Deborah
Low-Cost Throttle-by-Wire-System Architecture for Two-Wheeler Vehicles03-17-05-00353/4/2024
This article investigates the performance of a low-cost throttle-by-wire-system (TbWS) for two-wheeler applications. Mopeds/scooters are still restricted as environmentally harmful. TbWSs can contribute to environmental protection by replacing conventional restrictors. Its consisting of an anisotropic magnetoresistance (AMR) throttle position sensor and a position-controlled stepper motor-driven throttle valve actuator. The decentralized throttle position sensor is operating contactless and acquires redundant data. Throttle valve actuation is realized through a position-controlled stepper motor, sensing its position feedback by Hall effect. Using a PI controller, the stepper motor position is precisely set. Both units transmit and receive data by a CAN bus. Furthermore, fail-safe functions, plausibility checks, calibration algorithms, and energy-saving modes have been implemented. Both modules have been evaluated through hardware-in-the-loop testing in terms of reliability and measuring/positioning performance before the system was integrated into a Peugeot Kisbee 50 4T (Euro 5/injected). Finally, the sensor unit comes with a measurement deviation of less than 0.16%, whereas the actuator unit can approach throttle valve positions with a deviation of less than 0.37%. The actuators’ settling time does not exceed 0.13 s in the case of stable, step loss free, and noiseless operation.
Kreß, Jannis, Rau, Jens, Hebert, Hektor, Schmidt, Karsten, Perez-Peña, Fernando, Morgado-Estévez, Arturo
NVH Refinement of Small Commercial Vehicle2024-26-02191/16/2024
In today's volatile market environment, and with the change of user priorities, NVH refinement results in silent, vibration-free vehicle. The commercial vehicle industry is also starting to embrace this development in NVH vehicle refinement. There are health concerns associated with the discomfort experienced by occupants. This calls for cabins with no boom noise and less tactile vibrations. Noise within the vehicle is contributed by excitation from the Powertrain, Intake, Exhaust system, driveline, road excitations, suspension (structure borne noise) and its radiation into the air (air borne noise). This paper discusses the approach used to reduce “In-cab boom” noise in the operating speed sweep condition and seat track vibration during engine IDLE condition to improve driver comfort. In this paper NVH refinement was carried out on small commercial vehicles. Higher Seat track vibrations during IDLE and cabin boom noise during wide open throttle condition were observed during development of the product viz. small commercial vehicles. One of the rigid body power train modes was coupled with IDLE excitation firing frequency in the vehicle. The use of optimized PT mounts stiffness, resulted into separation of PT rigid body mode from IDLE frequency excitation and thus reducing the seat track vibrations to acceptable level. Another challenge was of In-cab noise with boom perception in speed sweep condition in customer driving pattern in another small commercial vehicle which was contributed by Exhaust and Intake noise. The exhaust engine firing orders were attributed to higher In-cab noise. Boom noise perception was reduced with silencer design optimization without affecting back pressure. The silencer design optimization was carried out through TL prediction. Intake noise is mostly attenuated by passive control techniques. One of the technique is Helmholtz resonator. Helmholtz resonator was designed and evaluated on vehicle to address resonance at Intake system for the vehicle. The journey involves various tasks including noise, vibration measurement and analysis, PT mounting stiffness tuning, virtual simulation and evaluation on the vehicle. It was observed that the engine mounts with correct stiffness’s, seat track vibrations decreased by more than 50% during IDLE, optimised design of exhaust silencer & with Helmholtz resonator at Intake system, the cabin boom noise was reduced by 6 to 8 dB(A) resulted into the targeted NVH performance.
Yeola, Yogesh, Kharpude, Yogesh, Kalsule, Dhanaji, Choudhary, Aditya, Sonar, Santosh, Nikam, Avinash
A Comparative Study of Methanol-Gasoline Blends on Performance and Emissions on BS-IV and BS-VI Class of Two Wheeler Vehicles2024-26-00731/16/2024
Methanol, a fuel obtainable through the capture and conversion of Carbon Dioxide (CO2), has garnered attention as a suitable alternative fuel for gasoline. Methanol-gasoline blends, characterized by their high-octane rating, commendable performance, and reduced carbon emissions, present themselves as promising alternative fuels for internal combustion engines. In the present study, a comprehensive comparative analysis was conducted to assess the performance and emissions characteristics of unmodified vehicles utilizing methanol blends at lower concentrations, ranging up to 30%, in gasoline. The research focused on two distinct classes of vehicles commonly found on the roads of India: those compliant with BS-IV (Euro IV) and BS-VI (Euro VI) emission standards. Experimental evaluations were carried out on a chassis dynamometer, with the vehicles subjected to the Worldwide Harmonized Motorcycle Test Cycle (WMTC) and Wide open throttle (WOT) driving tests. The emissions from these vehicles were meticulously collected and subjected to detailed analysis to assess the key performance and emission parameters. It was observed that the methanol blends are suitable for BS-IV vehicles without any modifications; however, the BS-VI vehicles need the ECU models to be recalibrated for their adoption of methanol blends.
Teja, Ravi, Khandai, Chinmayananda, Muralidharan, M
Flame structure characteristics and performance comparison of a NG SI engine under stoichiometric and lean combustion using CFD2023-36-01201/8/2024
The development and improvement of efficient compressed natural gas (CNG) engines align with efforts to reduce greenhouse gas and pollutant emissions. The objective of this study is to evaluate the flame structure and compare the performance characteristics of an engine powered by compressed natural gas (CNG) under stoichiometric and lean combustion in wide open throttle. CFD simulation alongside experimental tests are performed. The experimental data were obtained using a Hyundai 2.5-liter HR engine, originally a Diesel engine, adapted for spark ignition operation. Lean and stoichiometric conditions were evaluated at compression ratio 14:1, operating at 1800 rpm in MBT spark timing. The results showed that increasing lambda (λ) had a significant effect on apparent heat release rate, laminar flame speed, flame thickness and flame surface area. While the flame speed decreased in a leaner operating condition, the flame thickness and surface area increased due to reduced reaction rates and extended combustion duration. By reducing the flame speed but increasing its surface area, the amount of unburned fuel does not experience a significant increase, while the heat losses to the cylinder walls are reduced. When comparing the total energy between the two conditions and the indicated thermal efficiency, the lean operation achieved an absolute increase of almost 1% in efficiency, from 37.41% in stoichiometric condition to 38.34% in lean condition. This highlights the need to explore lean operation to increase the efficiency of internal combustion engines using natural gas.
da Silva, Cristian Douglas Rosa, França, Louise Bomfim Magalhães, Fagundez, Jean Lucca Souza, Lanzanova, Thompson Diórdinis Metzka, Martins, Mario Eduardo Santos
Simulation and On-Road Testing of VTS on a Heavy Duty Diesel Engine Truck2023-01-167210/31/2023
Estimated engine torque is an important parameter used by automotive systems for automated transmission and clutch control. Heavy-duty engine and transmission manufacturers widely use SAE J -1939 based ECU torque calculation based on mass air/fuel flow steady state maps created during calibration of the engine for this purpose. As an alternative, to enhance the accuracy of this important control variable, a virtual flywheel torque sensor (VFTS) was developed. It measures the engine torque based on the harmonics of the instantaneous flywheel speed signal. Initial dynamometer testing showed the VFTS estimated torque values exhibited a maximum inaccuracy of 12% of the actual measured torque over the range of conditions tested. In this paper we report the results of on road truck testing of the VFTS. A loaded heavy truck with a gross vehicle weight rating of 80,000 pounds was used. The performance of the VFTS was tested in different gears at full throttle in the diesel engine speed range of 1000 RPM to 1900 RPM. The accuracy of the VFTS sensor is found to vary with gear ratio, depending on the speed and road conditions. The VFTS showed better accuracy in higher gears than in lower gears. Further, an AMEsim truck drivetrain dynamic modelling was performed for comparing and analyzing the performance of the VFTS with test results under different load and speed conditions in different gears. These results showed good agreement between the simulation and experiment at full throttle in high gears.
Iddum, Vivek, Bair, John, Chahal, Iqbal Singh, Mason, Paul, Ghantasala, Muralidhar K.
Experimental Comparison of a Rotary Valvetrain on the Performance and Emissions of a Light Duty Spark Ignition Engine2023-01-161310/31/2023
Rotary valve technology can provide increased flow area and higher discharge coefficients than conventional poppet valves for internal combustion engines. This increase in intake charging efficiency can improve the power density of four-stroke internal combustion engines, particularly at high engine speeds, where flow is choked through conventional poppet valves. In this work, the valvetrain of a light duty single cylinder spark ignition engine was replaced with a rotary valve train. The impact of this valvetrain conversion on performance and emissions was evaluated by comparing spark timing sweeps with lambda ranging from 0.8 to 1.1 at wide open throttle. The results indicated that the rotary valvetrain increased the amount of air trapped at intake valve closing and resulted in a significantly faster burn duration than the conventional valvetrain. Additionally, the spark to CA10 burn duration of the rotary valvetrain was highly sensitive to spark timing, which was not true of the baseline engine, nor is it true of conventional spark ignition engines in general. The explanation behind this rapid combustion and high combustion duration sensitivity to spark time is related to the large amount of tumble induced by the flow through the rotary valve, which is unabated axially downward unlike with a poppet valve. Thus, the rotary valve showed not only improved power density, but more rapid combustion. However, the rotary valve does introduce channels which appear to have negatively impacted unburned hydrocarbon emissions. To complete the study, a load sweep was performed at 3300 rpm, demonstrating that there was a slight brake specific NOx benefit to the rotary valvetrain despite producing higher unburned hydrocarbons, particularly at part load operation.
Gainey, Brian, Vaseleniuck, Darrick, Cordier, Dan, Garrett, Norman
Combustion, Performance, Emissions and Energy Analysis of Hydrogen Fuelled Spark-Ignition Engine under Lean Burn Condition2023-28-13345/25/2023
The design and development of a hydrogen powered spark-ignition engine, aimed for installation on a vehicle for on-road application. The experiment was conducted at WOT (Wide Open Throttle) condition at a speed of 4000 rpm with an excess air-fuel ratio of 1.3, 1.5, 2.2, 2.5, 3, 3.75, and 4.0. The ignition timing was optimized for maximum torque at each value of the excess air ratio. The various parameters analyzed such as in-cylinder pressure, Pressure and Volume, Logarithm of Pressure and Volume, Mass fraction burned, Cummulative heat release, Net heat release, Rate of pressure rise, and Mean gas temperature. The results show that there is a profound effect of excess air-fuel ratio on the engine’s mean effective pressure, output power, Brake thermal efficiency, Volumetric efficiency, Brake specific fuel consumption, and NOx emissions. The peak cylinder pressure decreases with an increase in excess air-fuel ratio and NOx emissions are reduced due to reduced mean gas temperature. Also, fuel energy is analyzed to review fuel energy converted to net power, heat lost to exhaust gas and coolant. The aim of researchers is to analyze the engine which is in production and confirm their suitability for meeting future emissions norms with minor modifications to meet Sustainable Development Goals(SDG).
Shinde, Apurwa, KARUNAMURTHY, K, SHINDE, BALU JALINDAR, Rairikar, Sandeep, Thipse, Sukrut S
Non Linear Estimator Design for Air to Fuel Ratio Measurement Using Neural Network Based Approach in Spark Ignited Engine2023-01-03824/11/2023
Precise measurement of Air-fuel ratio (AFR) or Lambda value plays a substantial role in controlling exhaust emission from an internal combustion engine. Estimation of AFR is a significant factor to determine the engine performance and to optimize the catalyst conversion efficiency which has direct impact on increase or decrease of emissions. Most of the production two-wheeler engine determines AFR by using non-linear lambda sensor (Narrow band oxygen sensor) but it limits the AFR control due to restrictions in its performance and operating time. A wideband lambda sensor is more accurate and faster but may not be economical to place on low-cost vehicles. A time varying ion current signal can be easily captured on vehicle with minimal additional requirements. AFR has direct correlation with various engine parameters such as Engine speed, Throttle position sensor (TPS), Manifold air pressure (MAP), Fuel injection pulse width (FPW), etc. These signals can be captured with the pre installed vehicle sensors. Neural network-based model can be designed and trained to estimate AFR from different vehicle parameters. Results of neural network model can be improved by considering narrowband sensor as an additional input along with others inputs. The work presented in this paper is implemented for a production vehicle ignition system for two wheeled vehicles. Multiple engine parameters as an input and Universal exhaust gas oxygen sensor (UEGO) as an output are acquired using a data acquisition system. The data is used to train and validate the neural network model to determine the possibility of using it for accurate AFR estimation. A wide range of lambda sensor is considered by performing experiment at different engine operating conditions. The model is validated for steady state as well as dynamic operating condition by running engine on dynamometer and by riding vehicle on day traffic scenario respectively. A detailed study is presented to compare the various models of artificial neural network (ANN) and recurrent neural network (RNN). The paper discusses the results by considering the effect of variation in different neural network model parameters along with engine parameters.
Bagade, Monika Jayprakash, Das, Himadri, Mandloi, Deepak, R, Harini
Research on Cooperative Adaptive Cruise Control (CACC) Based on Fuzzy PID Algorithm2023-01-06824/11/2023
For cooperative adaptive cruise control (CACC) system, a robust following control algorithm based on fuzzy PID principle is adopted in this paper. Firstly, a nonlinear vehicle dynamics model considering the lag of driving force and acceleration constraints was established. Then, with the vehicle’s control hierarchic, the upper controller takes the relative speed between vehicles and the spacing error as inputs to output the following vehicle's target acceleration, while the lower controller takes the target acceleration as inputs and the throttle opening and brake master cylinder pressure as outputs. For the setting of target spacing, this paper additionally considers the relative speed between vehicles and the acceleration of the front vehicle. Through testing, compared with the traditional variable safety distance model, the average distance reduces by 5.43% when leading vehicle is accelerating, while increases by 2.74% in deceleration. For the fixed-speed cruise mode, a set of logic judgment algorithm is used to replace the traditional method of designing an extra set of PID controller, which reduces the algorithm complexity while achieving the same control effect. Finally, Simulink/Carsim co-simulation test was carried out in different conditions. The distance error was less than 0.2m under the variable speed following condition, and the spacing error was less than 0.8m under the sudden braking condition where the acceleration of the pilot vehicle was -0.7g. The vehicle can easily switch smoothly between the following mode and the constant speed mode under the cutting-in and cutting-out conditions of the leading vehicle. Our system meets the safety requirements under all conditions, the changing trend of the speed curve and acceleration curve of the following car in each working condition and is more moderate than that of the front car, so as to ensure the comfort of passengers.
Zhu, Mingyang, Tan, Gangfeng
Minimizing Steady-State Testing Time in an Engine Dynamometer Laboratory2023-01-02094/11/2023
In the automotive industry, performing steady-state tests on an internal combustion engine can be a time consuming and costly process, but it is necessary to ensure the engine meets performance and emissions criteria set by the manufacturer and regulatory agencies. Any measures that can reduce the amount of time required to complete these testing campaigns provides significant benefits to manufacturers. The purpose of this work is then to develop a systematic approach to minimize the time required to conduct a steady-state engine test campaign using a Savitsky-Golay filter to calculate measured signal gradients for continuous steady-state detection. Experiments were conducted on an Armfield CM11-MKII Gasoline Engine test bench equipped with a 1.2L 3-cylinder Volkswagen EA111 R3 engine. The test bench utilizes throttle position control and an eddy current dynamometer braking system with automatic PID control of engine speed. Data from engine signals (e.g. exhaust temperature, engine speed, air-fuel ratio etc.) were continuously collected, allowing for detection of steady-state and further analysis in post-processing. In this preliminary work, two distinct approaches were studied for generating a map of engine data in the typical load/speed operating space: 1) a constant-speed variable-throttle/load sweep, and 2) a constant-throttle variable-speed sweep. Both test approaches were equally capable of generating the desired engine operating map, but using the second approach, i.e., the constant-throttle sweep, saved an average of 41 seconds per operating point, representing a 15% reduction in total time to steady-state for the operating points tested. This reduction was due to the decrease in exhaust temperature change between engine operating points associated with changes in engine speed as opposed to changes in engine load, as well as the improved dynamic response in engine speed of the eddy current dynamometer braking system.
DeCoste, Steven, Scalzi, Antonio, Chen, Jun, DelVescovo, Dan
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