Journal Articles - SAE Mobilus

SAE journals provide rigorously peer-reviewed, archival research by subject matter experts--basic and applied research that is valuable to both academia and industry.

Items (11,967)
This article addresses the essential task of understanding vibrations produced by vehicles to enhance the design of authentic laboratory tests. The article focuses on two primary sources of vibrations: those arising from vehicle–road surface interaction, which is largely random, and those emanating from the drivetrain, characterized as a summation of harmonics with a time-varying fundamental frequency. The method involves the application of the extended Kalman filter (EKF) paired with robust nonlinear least-squares (NLS) initialization to isolate the harmonic components effectively. Through a comprehensive analysis involving mean-square-error (MSE) evaluation via Monte Carlo simulation, considering additive white Gaussian noise (AWGN) and a two-degrees-of-freedom quarter-car model’s simulation response to the road, the research demonstrates the EKF’s proficiency. The results indicate the EKF’s capability to accommodate AWGN with a signal-to-noise ratio (SNR) up to 0 dB and road-induced
Sierra-Alonso, Edgar F.Rouillard, VincentLamb, Matthew
Arrays of radial cracks often appear at the bore of pressurized cylinders, posing potential safety risks and leading to possible structural failures. This article presents an analytical approach to evaluate the stress field arising from single or multiple uniform radial cracks in thick-walled pressurized cylinders within the context of linear elastic fracture mechanics (LEFM) under mode-I loading. This formulation is based on the fundamental equations of elasticity and approximations of stress intensity factors (SIF) reported in the literature. Hence, the SIF were revisited and their range of validity was highlighted. The study considers two types of internal pressure loading: one applied only to the cylinder’s inner surface with no pressure on the crack faces and another applied to both the inner surface and the crack faces. The influence of the number and length of cracks relative to cylinder thickness on the stress field is analyzed. A finite element model of the pressurized vessel
Methia, MounirBenslimane, AbdelhakimBechir, HocineAït Hocine, Nourredine
A numerical investigation has been performed in the current work on reactivity-controlled compression ignition (RCCI), a low-temperature combustion (LTC) strategy that is beneficial for achieving lower oxides of nitrogen (NOx) and soot emission. A light-duty diesel engine was modified to run in RCCI mode. Experimental data were acquired using diesel as HRF (high-reactivity fuel) and gasoline as LRF (low reactivity fuel) to check the accuracy and fidelity of predicted results. Blends of ethanol and gasoline with DTBP (di-tert-butyl peroxide) addition in a small fraction on an energy basis were used in numerical simulations to promote ignitability and reactivity enhancement of PFI charge. Achieving stable, smooth, and gradual combustion in RCCI is challenging at low loads, especially in light-duty engines, due to misfiring and poor combustion stability. DTBP is known for enhancing cetane number and accelerating combustion, and it is mixed in a PFI blend to avoid combustion deterioration
Tripathi, SaurabhKrishnasamy, Anand
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, MichaelDuvall, AndrewWallner, Thomas
The EN24 and EN42 materials were machined by the electric discharge machine (EDM). The study aimed to optimize the input variables for the multiple outputs, such as metal removal rate (MRR), tool wear rate (TWR), and surface roughness. The machining of the metal is essential to analyze the surface quality and the production rate. The MRR is a prediction of the production rate and surface roughness resembling the quality of the surface. The input variables were current (A), pulse on time (ton), and pulse duty factor (T). The three levels of current were 3A, 6A, and 9A. The ton time was selected as 30 μs, 50 μs, and 70 μs. The pulse duty factors were selected as 4, 5, and 6. The Taguchi optimization techniques are used to optimize process parameters. The L9 orthogonal array was selected for the process. ANOVA analysis was employed to check the rank of the input parameters relative to the output. The maximum MRR were at 9A, 70 μs, and 4 duty factor for the EN24. The best MRR were at 9A
Sahu, Kapil DevSingh, RajnishChauhan, Akhilesh Kumar
Three dynamic models of a passenger car including the one-dimensional dynamic model, two-dimensional dynamic model, and three-dimensional dynamic model are built to evaluate the ride quality of the passenger car as well as the isolating performance of the SNS (structure of negative stiffness). The decrease of the root-mean-square (RMS) accelerations in the seat and car’s body shaking is the research goal. The investigation results indicate that under all working conditions including the various excitations of the road surface and various velocities of the passenger car, the seat’s acceleration with SNS is strongly ameliorated in comparison without SNS in all three models of the passenger car. Particularly, the RMS seat acceleration with SNS in one-, two-, and three-dimensional models is strongly reduced in comparison without SNS by 76.87%, 66.15%, and 70.59%, respectively. Thus, the seat’s SNS has a good effect in isolating the vertical vibration of the passenger car’s seat. However
Zhang, LeiLi, TaoYang, Guixing
In this investigation, AA6351 alloy matrix composites with a larger volume proportion of SiC (20 wt%) were fabricated and tested for microstructure and mechanical behavior. Composites were hot extruded from mechanically milled matrix and reinforcements. Hot extrusion uniformly distributed reinforcements in the matrix and strengthened phase interaction. Mechanical ball milling causes AA6351 powder to become more homogeneous, reducing the mean particle size from 38.66 ± 2.31 μm to 23.57 ± 2.31 μm due to particle deformation. The micrograph shows that the SiC particles are equally dispersed in the AA6351 matrix, avoiding densification and reinforcing phase integration issues during hot extrusion. In hot extrusion, SiC particles are evenly distributed in the matrix, free of pores, and have strong metallurgical bonds, resulting in a homogenous composite microstructure. SiC powders and mechanical milling increase microhardness and compressive strength, giving MMC-A 54.9% greater than AA6351
Saiyathibrahim, A.Murali Krishnan, R.Jatti, Vinaykumar S.Jatti, Ashwini V.Jatti, Savita V.Praveenkumar, V.Balaji, K.
Global warming has intensified environmental challenges such as more intense heat waves due to the accumulation of greenhouse gases, primarily carbon dioxide (CO2), which is heavily produced in power generation and transportation sectors, traps heat and raises the Earth’s temperature. Significant measures must be taken to reduce its production and impact on our environment. Hydrogen (H2) enrichment is a promising technology that enables higher thermal efficiencies and lower exhaust emissions. However, various parameters need to be optimized for internal combustion engines (ICE), which increases experimental and computational costs. The main goal of this work is to offer a reliable correlation that can be used as an input parameter for turbulent combustion models to enhance predictions and lower the cost of running simulations. Thus, the laminar burning velocity (LBV) of binary fuel mixtures is investigated numerically over a wide range of initial conditions (300–600 K and 1–11 atm) and
Almansour, Bader
The aim of this work was to investigate the influence of different combinations of engine oil and oil additive as well as additivated and unadditivated fuel on particulate emissions in gasoline engines. To accomplish this, load, speed, and type of oil injection were varied on a single-cylinder engine, and the influence on particle number concentration and size distribution were evaluated. The tests were supplemented by an optical investigation of their in-cylinder soot formation. The investigation of fuel additives showed no significant differences compared to the reference fuel without additives. However, in the case of oil additives, detergents led to a significant increase in the number of particles in the <20 nm range. This effect occurred when used as both a single additive and a component in the standard engine oil. While viscosity improvers also lead to a measurable, but less pronounced, increase in the particle number concentration, no significant influence can be determined
Böhmeke, ChristianHeinz, LukasWagner, UweKoch, Thomas
The societies around the world remain far from meeting the agreed primary goal outlined under the 2015 Paris Agreement on climate change: reducing greenhouse gas (GHG) emissions to keep global average temperature rise to well below 20°C by 2100 and making every effort to stay underneath of a 1.5°C elevation. In 2020 direct tailpipe emissions from transport represented around 8 GtCO2eq, or nearly 15% of total emissions. This number increases to just under 10 GtCO2eq when indirect emissions from electricity and fuel supply are added, for a total share of roughly 18%. Following the current trend, direct and indirect emissions in transport could reach above 11 GtCO2eq by 2050. Roughly 76% of transport emissions are related to land-based passenger and freight road transport. Emissions from aviation and shipping account for the remaining 24% of 2020 emissions. Hydrogen (H2) is in this scenario considered to play a key role as a carbon-free and versatile energy carrier. Combustion of hydrogen
Koerfer, ThomasDurand, ThomasVirnich, Lukas
Reducing vehicle weight is a key task for automotive engineers to meet future emission, fuel consumption, and performance requirements. Weight reduction of cylinder head and crankcase can make a decisive contribution to achieving these objectives, as they are among the heaviest components of a passenger car powertrain. Modern passenger car cylinder heads and crankcases have greatly been optimized in terms of cost and weight in all-aluminum design using the latest conventional production techniques. However, it is becoming apparent that further significant weight reduction cannot be expected, as processes such as casting have reached their limits for further lightweighting due to manufacturing restrictions. Here, recent developments in the additive manufacturing (AM) of metallic structures is offering a new degree of freedom. As part of the government-funded research project LeiMot [Lightweight Engine (Eng.)] borderline lightweight design potential of a passenger car cylinder head with
Kayacan, CanPischinger, StefanAhlborn, KlausBültmann, Jan
Electromechanically actuated drum brakes are one interesting option for the realization of brake-by-wire systems for future electric vehicles. A key characteristic for the design and control of electromechanical brake actuators is the actuation point stiffness, as this quantity relates the actuation force to the required actuator position. The various known approaches for the control of electromechanical brakes, which primarily focus on disc foundation brakes, typically rely on the stiffness curve at least to some extent. A transfer of these approaches to drum brakes is not straightforward, because the actuation point stiffness for drum brakes is much more complex compared to disc brakes. In particular, a strong hysteretic behavior is observed for the standing drum and a considerable change of the stiffness and hysteresis can be observed for the rotating drum. Although drum brakes have been used for decades these effects have not been thoroughly discussed in literature, yet. Hence
Peter, SimonJanhsen, MichaelStümke, DanielGörges, Daniel
The emergence of the flying ad hoc network (FANET) has gained popularity after COVID-19 pandemic. Due to disruptions in ground-based monitoring, aerial monitoring has become the preferred approach. Aerial communication has become essential, with multiple aerial vehicles equipped with sensors forming a FANET in a specific geographical area. These vehicles communicate autonomously in an ad-hoc fashion using hello packets, but the periodic transmission of these packets consumes a significant amount of energy. This type of aerial communication is particularly useful in infrastructure-fewer conditions, and the transition from 4G to 5G infrastructure has further facilitated aerial communication. To address limited flight periodicity of aerial vehicles due to onboard battery constraints, a new deep hello routing, GeNp-ODHR has been proposed to optimize the battery consumption and performance, which indirectly extended the flight time by saving the energy. Through simulation-based testing
Saini, Hemant Kumar
The braking system stands as a vital component within a vehicle; its malfunction has the potential to precipitate catastrophic or severe accidents. There are two primary backup strategies: one involves hardware redundancy, and the other is the optimization of software strategies in conjunction with other systems. Redundancy among various actuators of the second strategy not only maximizes the vehicle’s inherent capabilities but also results in cost savings. In this article, a multilevel backup strategy that integrates electro-hydraulic braking, driving systems, and electronic parking brake systems is explored. Utilizing a self-developed braking safety control system, a proposal is made for the electronic parking brake to participate in service braking. Additionally, two functional modules, pre-clamping and deceleration following, have been meticulously designed to tackle the challenges of response delay and insufficient control precision that are commonly associated with electronic
Tian, BoshiLi, LiangLiao, YinshengLv, HaijunWang, XiangyuHu, ZhimingSun, YueQu, Wenying
Transportation contributes 27% of the greenhouse gas emissions in the US. Governments worldwide are developing new programs to hasten the adoption of electric vehicles (EVs) in the transition to zero-emission vehicles. However, the success of EV adoption generally depends on user preferences. This study explores what we can find out about consumer preferences while accounting for unobserved heterogeneity. Consumer choices for EVs, including plug-in EVs (PEVs) and fuel-cell EVs (FCEVs), are analyzed using the California Vehicle Survey (2019) data. Several factors are examined, including the availability of clean source energy (installed solar panels) at home, preferable location for recharging PEVs, past driving experience with EVs, availability of public charging infrastructure, and sociodemographic factors. A mixed multinomial (random parameter) logit model is estimated, exploring the associations between the selected variables and EV consumer preferences while accounting for
Moradloo, NastaranMahdinia, ImanKhattak, Asad
In order to meet the driving characteristics and needs of different types of drivers and to improve driving comfort and safety, this article designs personalized variable transmission ratio schemes based on the classification results of drivers’ steering characteristics and proposes a switching strategy for selecting variable transmission ratio schemes in response to changes in driver types. First, data collected from driving simulator experiments are used to classify drivers into three categories using the fuzzy C-means clustering algorithm, and the steering characteristics of each category are analyzed. Subsequently, based on the steering characteristics of each type of driver, suitable speed ranges, steering wheel travel, and yaw rate gain values are selected to design the variable transmission ratio, forming personalized variable transmission ratio schemes. Then, a switching strategy for variable transmission ratio schemes is designed, using a support vector machine to build a
Chen, ChenZheng, HongyuZong, Changfu
This study explores the effectiveness of two machine learning models, namely multilayer perceptron neural networks (MLP-NN) and adaptive neuro-fuzzy inference systems (ANFIS), in advancing maintenance management based on engine oil analysis. Data obtained from a Mercedes Benz 2628 diesel engine were utilized to both train and assess the MLP-NN and ANFIS models. Six indices—Fe, Pb, Al, Cr, Si, and PQ—were employed as inputs to predict and classify engine conditions. Remarkably, both models exhibited high accuracy, achieving an average precision of 94%. While the radial basis function (RBF) model, as presented in a referenced article, surpassed ANFIS, this comparison underscored the transformative potential of artificial intelligence (AI) tools in the realm of maintenance management. Serving as a proof-of-concept for AI applications in maintenance management, this study encourages industry stakeholders to explore analogous methodologies. Highlights Two machine learning models, multilayer
Pourramezan, Mohammad-RezaRohani, Abbas
Vibration comfort is a critical factor in assessing the overall performance of engineering machinery, with significant implications for operator health and safety. However, current evaluation methods lack specificity for construction machinery, impeding accurate prediction of vibration comfort and hindering the optimization of noise, vibration, and harshness (NVH) performance. To address this challenge, this article proposes a model that combines a random forest with a genetic algorithm (GA-RF) to enable rapid and accurate prediction of vibration comfort in construction machinery cabins. The approach begins with an improved objective evaluation methodology for extracting key features from vibration signals at five measurement points: seat, floor, back, and left and right armrests. Additionally, subjective evaluation technology, combining semantic differential and rating scales, is employed to capture operators’ personal comfort perceptions. The implementation of the GA-RF model
Zhao, JianYin, YingqiChen, JiangfeiZhao, WeidongDing, WeipingHuang, Haibo
Modern diesel engines temporarily use a very late post-injection in the combustion cycle to either generate heat for a diesel particulate filter regeneration or purge a lean NOx trap. In some configurations, unburned fuel is left at the cylinder walls and is transported via the piston rings toward the lower crankcase region, where fuel may dilute the oil. Reduced oil lubrication shortens the oil service intervals and increases friction. Beside diesel fuel, this problem may also occur for other types of liquid fuels such as alcohols and e-fuels. The exact transport mechanism of the unburned fuel via the piston ring pack grooves and cylinder wall is hard to measure experimentally, motivating numerical flow simulation in early design stages for an in-depth understanding of the involved processes. A new CFD simulation methodology has been developed to investigate the transient, compressible, multiphase flow around the piston ring pack, through the gap between piston and liner, and its
Antony, PatrickHosters, NorbertBehr, MarekHopf, AnselmKrämer, FrankWeber, CarstenTurner, Paul
Toward the goal of “dual carbon economy” development, new energy hybrid commercial vehicles have become the main vehicles to meet the future fuel consumption and emission targets. In order to meet the high requirements of commercial vehicles on power and to minimize the influence of ambient temperature on the power of the vehicle, this study proposes a composite energy storage system (CESS) incorporating ultracapacitors. To further understand the impact of ultracapacitor on the dynamic performance of the vehicle, this study compares the dynamics of series range-extended hybrid pickup trucks with and without ultracapacitor at ambient and low temperatures, as well as the effect of ultracapacitor on the service life of lithium-ion batteries, by means of simulation. The results show that at room temperature (25°C), the addition of ultracapacitor shortens the 0–100 km/h acceleration time of the whole vehicle by 24.4% and improves the off-road climbing performance by 11.7%; at low
Yu, Xiaocao
This article proposes a new model for a cooperative and distributed decision-making mechanism for an ad hoc network of automated vehicles (AVs). The goal of the model is to ensure safety and reduce energy consumption. The use of centralized computation resource is not suitable for scalable cooperative applications, so the proposed solution takes advantage of the onboard computing resources of the vehicle in an intelligent transportation system (ITS). This leads to the introduction of a distributed decision-making mechanism for connected AVs. The proposed mechanism utilizes a novel implementation of the resource-aware and distributed–vector evaluated genetic algorithm (RAD-VEGA) in the vehicular ad hoc network of connected AVs as a solver to collaborative decision-making problems. In the first step, a collaborative decision-making problem is formulated for connected AVs as a multi-objective optimization problem (MOOP), with a focus on energy consumption and collision risk reduction as
Ghahremaninejad, RezaBilgen, Semih
This study aims to elucidate the impact of A-pillar blind spots on drivers’ visibility of pedestrians during left and right turns at an intersection. An experiment was conducted using a sedan and a truck, with a professional test driver participating. The driver was instructed to maintain sole focus on a designated pedestrian model from the moment it was first sighted during each drive. The experimental results revealed how the blind spots caused by A-pillars occur and clarified the relationship between the pedestrian visible trajectory distance and specific vehicle windows. The results indicated that the shortest trajectory distance over which a pedestrian remained visible in the sedan was 17.6 m for a far-side pedestrian model during a right turn, where visibility was exclusively through the windshield. For the truck, this distance was 20.9 m for a near-side pedestrian model during a left turn, with visibility through the windshield of 9.5 m (45.5% of 20.9 m) and through the
Matsui, YasuhiroOikawa, Shoko
In this research, we propose a set of reporting documents to enhance transparency and trust in artificial intelligence (AI) systems for cooperative, connected, and automated mobility (CCAM) applications. By analyzing key documents on ethical guidelines and regulations in AI, such as the Assessment List for Trustworthy AI and the EU AI Act, we extracted considerations regarding transparency requirements. Recognizing the unique characteristics of each AI system and its application sector, we designed a model card tailored for CCAM applications. This was made considering the criteria for achieving trustworthy autonomous vehicles, exposed by the Joint Research Centre (JRC), and including information items that evidence the compliance of the AI system with these ethical aspects and that are also of interest to the different stakeholders. Additionally, we propose an MLOps Card to share information about the infrastructure and tools involved in creating and implementing the AI system
Cañas, Paola NataliaNieto, MarcosOtaegui, OihanaRodriguez, Igor
The present work deals with the effects of nano-additives on ternary blend biodiesel fuel added in diesel engine. The ternary blend comprises of mustard oil biodiesel and rice bran oil biodiesel, synthesized by means of transesterification and diesel. Nano-additives used in the current study include carbon nanotubes (CNT) and MgO/MgAl2O4 spinel, which were added in a suitable concentration to the biodiesel. CNTs were procured from the market and MgO/MgAl2O4 spinel was prepared by co-precipitation via ball milling process. The nano-additives were characterized by means of FTIR (Fourier transform infrared spectroscopy), AFM (atomic force microscopy), and DSC (differential scanning calorimetry) analysis. Biodiesel blend samples were prepared such as B20 (20% biodiesel + 80% diesel), B20 + CNT (1000 PPM), B20+MgO/MgAl2O4 spinel (1000 PPM), and B20+CNT+MgO/MgAl2O4 spinel (1000 PPM) were tested against diesel fuel. The maximum increase in brake thermal efficiency (BTE), oxides of nitrogen
Jeyakumar, NagarajanDhinesh, BalasubramanianPapla Venugopal, Inbanaathan
The increased use of computational human models in evaluation of safety systems demands greater attention to selected methods in coupling the model to its seated environment. This study assessed the THUMS v4.0.1 in an upright driver posture and a reclined occupant posture. Each posture was gravity settled into an NCAC vehicle model to assess model quality and HBM to seat coupling. HBM to seat contact friction and seat stiffness were varied across a range of potential inputs to evaluate over a range of potential inputs. Gravity settling was also performed with and without constraints on the pelvis to move towards the target H-Point. These combinations resulted in 18 simulations per posture, run for 800 ms. In addition, 5 crash pulse simulations (51.5 km/h delta V) were run to assess the effect of settling time on driver kinematics. HBM mesh quality and HBM to seat coupling metrics were compared at kinetically identical time points during the simulation to an end state where kinetic
Wade von Kleeck, B.Caffrey, JulietteWeaver, Ashley A.Gayzik, F. ScottHallman, Jason
The electronic mechanical brake (EMB) system is a critical actuator for achieving brake-by-wire control. This review categorizes and summarizes the literature related to EMB into three sections: actuator, mathematical modeling, and control strategies. In the actuator aspect, this article compares and analyzes motors, motion conversion mechanisms, and self-reinforcing mechanisms. For mathematical modeling, this article reviews modeling methods for EMB systems concerning motors, transmission mechanisms, friction, contact collisions, nonlinear stiffness, and hysteresis characteristics. Regarding control strategies, this article consolidates methods for clamp force control, clamp force estimation, and gap management. Finally, the article discusses potential future research directions in EMB from both hardware structure and software algorithm perspectives
Yan, ZhoudongPeng, HangChen, XinboYan, Min
Model predictive control (MPC) plays a crucial role in advancing intelligent vehicle technologies. Controllers designed based on various vehicle reference models, including kinematic and dynamic models (both linear and nonlinear), often demonstrate significant differences in control performance. This study contributes by comparing three different MPC control methods and proposing a comprehensive evaluation criterion that considers tracking accuracy, stability, and computational efficiency across various MPC designs. Joint simulations using CarSim and MATLAB/Simulink reveal distinct performance characteristics among the MPC variants. Specifically, kinematic MPC (KMPC) exhibits superior performance at low speeds, linear model predictive control (LMPC) performs best at moderate speeds, and nonlinear MPC (NMPC) achieves optimal performance at high speeds. These findings highlight the adaptive nature of MPC strategies to varying vehicle dynamics and operational conditions, emphasizing the
Lai, FeiXiao, HaoLiu, JunboHuang, Chaoqun
With the influx of artificial intelligence (AI) models aiding the development of autonomous driving (AD), it has become increasingly important to analyze and categorize aspects of their operation. In conjunction with the high predictive power innate to AI solutions, due to the safety requirements inherent to automotive systems and the demands for transparency imposed by legislature, there is a natural demand for explainable and predictable models. In this work, we explore the various strategies that reveal the inner workings of these models at various component levels, focusing on those adapted at the modeling stage. Specifically, we highlight and review the use of explainability in state-of-the-art AI-based scenario understanding and motion prediction methods, which represent an integral part of any AD system. We break the discussion down across three key axes that are inherent to any AI solution: the data, the model architecture, and the loss optimization. For each of the axes, we
Okanovic, IlmaStolz, MichaelHillbrand, Bernhard
Accurate estimation of vehicle energy consumption plays an important role in developing advanced energy-saving connected automated vehicle technologies such as Eco Approach and Departure, PHEV mode blending, and Eco-route planning. The present study developed a reduced-order energy model with second-order response surfaces and torque estimation to estimate the energy consumption while just relying on the drive cycle information. The model is developed for fully electric Chevrolet Bolt using chassis dynamometer data. The dyno test data encompasses the various EPA test cycles, real-world, and aggressive maneuvers to capture most powertrain operating conditions. The developed model predicts energy consumption using vehicle speed and road-grade inputs for a drive cycle. The accuracy of the model is validated by comparing the prediction results against track and road test data. The developed model was able to accurately predict the energy consumption for track drive cycles within the error
Goyal, VasuDudekula, Ahammad BashaStutenberg, KevinRobinette, DarrellOvist, GrantNaber, Jeffery
The advent of neck braces for the helmeted motorcycle rider has introduced a pertinent research question: To what extent do they reduce measures related to the major mechanism of neck injury in unrestrained torso accidents, i.e., compression flexion (CF)? This question requires a suitable method of testing and evaluating the measures for a load case resulting in the required mechanism. This study proposes a weighted swinging anvil striking the helmeted head of a supine HIII ATD by means of a near vertex impact with a low degree of anterior head impact eccentricity to induce CF of the neck. The applied impact was chosen for the baseline (no neck brace) so that the upper and lower neck axial forces approached injury assessment reference values (IARV). The head impact point evaluated represents those typically associated with high-energy burst fractures occurring within the first 20 ms, with possible secondary disruption of posterior ligaments. The proposed test can be used to evaluate
de Jongh, Cornelis U.Basson, Anton H.Knox, Erick H.Leatt, Christopher J.
With the development of automotive intelligence and networking, the communication architecture of automotive network is evolving toward Ethernet. To improve the real-time performance and reliability of data transmission in traditional Ethernet, time-sensitive network (TSN) has become the development direction of next-generation of automotive networks. The real-time advantage of TSN is based on accurate time synchronization. Therefore, a reliable time synchronization mechanism has become one of the key technologies for the application of automotive Ethernet technology. The protocol used to achieve accurate time synchronization in TSN is IEEE 802.1AS. This protocol defines a time synchronization mechanism suitable for automotive Ethernet. Through the master clock selection algorithm, peer link delay measurement, and clock synchronization and calibration mechanism, the time of each node in the vehicle network is synchronized to a reference master clock. In addition, the protocol clearly
Guo, YiLuo, FengWang, ZitongGan, HaotianWu, MingzhiLiu, Hongqian
This article offers an algorithmic solution for moving a homogeneous platoon of position-controlled vehicles on a curved path with varying speeds and in the presence of communication losses and delays. This article considers a trajectory-based platooning with the leader–following communication topology, where the lead vehicle communicates its reference position and orientation to each autonomous follower vehicle. A follower vehicle stores this communicated information for a specific period as a virtual trail of the lead vehicle starting from the lead vehicle’s initial position and orientation. An algorithm uses this trail to find the follower vehicle’s reference position and orientation on that trail, such that the follower vehicle maintains a constant distance from the lead vehicle. The proposed algorithm helps form a platoon where each vehicle can traverse a curve with varying speeds. In contrast, in the existing literature, most of the solutions for vehicle platooning on a curved
Bhaskar, RintuWahi, PankajPotluri, Ramprasad
Ammonia-fired reciprocating engines have emerged as a promising technology in the maritime and power generation sector at medium-to-large scale (1–80 MW). The use of “on-the-fly” partial ammonia decomposition to produce a relatively small amount of hydrogen that can be used as combustion promoter, replacing fossil fuels in this function, enables this technology to provide carbon-free propulsion and power generation. In this context, it is envisioned that a hydrogen-fired prechamber ignition strategy offers significant advantages by accelerating the ammonia ignition and complete combustion process, increasing its reliability and robustness while still aiming to achieve low NO x , N2O, and NH3 emissions. This study exploits an OpenFOAM-based Large Eddy Simulation (LES) numerical modeling framework to investigate the ignition and combustion behavior of an ammonia main charge ignited by a hydrogen-fired prechamber. First, a conventional port-injection premixed configuration for the ammonia
Indlekofer, ThomasHaugen, Nils ErlandFørde, Olav ØyvindGruber, Andrea
Vehicle path tracking and stability management are critical technologies for intelligent driving. However, their controls are mutually constrained. This article proposes a cooperative control strategy for intelligent vehicle path tracking and stability, based on the stable domain. First, using the vehicle’s two-degrees-of-freedom (DOF) model and the Dugoff tire model, a phase plane representation is constructed for the vehicle’s sideslip angle and sideslip angular velocity. An enhanced method utilizing five eigenvalues is employed to partition the vehicle stability domain. Second, by employing the divided vehicle stable domain, the design of a fuzzy controller utilizes the Takagi–Sugeno (TS) methodology to determine the weight matrix gain for path tracking and stability control. Subsequently, a fuzzy model predictive control (TS-MPC) cooperative control strategy is designed, which takes into account both the precision of path tracking and the stability of the vehicle. Finally, a
Jiang, ShuhuaiWu, GuangqiangLi, YihangMao, LiboZhang, Dong
Motor temperature plays a critical role in controlling pump speed and regulating coolant flow to prevent overheating during motor operation. Presently, negative temperature coefficient (NTC) sensors are commonly used for motor temperature measurement, typically installed at the motor winding’s end for ease of installation. However, in oil spray-cooled motors, the temperature distribution is uneven due to the spray pipe, leading to lower temperatures near the pipe compared to other areas. This results in a challenge where relying solely on NTC measurements at the winding end may not meet the motor’s cooling requirements. To address this issue and improve temperature signal accuracy, a novel approach has been developed that utilizes four signals derived from the motor controller: motor speed, motor torque, along with oil pump speed, oil temperature. Employing the lumped parameter method, a model established in Simulink aims to estimate the average temperature in the motor’s high
Lu, JunjieLi, QiangChen, BinglinZhu, LunzhiWu, JianYan, Pingtao
The construction of urban transportation infrastructures on the supply side is severely limited due to the extensive development of central urban land. Therefore, optimizing the traffic structure with limited resources is particularly important. The work used the optimum capacity of the road network as one of the constraints. Multi-objective linear programming was used to establish the traffic structure model. The total travel volume, energy consumption, travel quality, and social cost were selected as the optimization objectives of the urban transportation structure. The influencing factors of infrastructure capacity (e.g., total travel demand, optimal capacity of road network, slow traffic capacity, and parking lot capacity) were selected as the constraint conditions in optimizing urban transportation structure. The objective was to develop an optimization model considering the constraints of urban infrastructure. Finally, the optimal traffic structure was compared with the actual
Zhang, JinweiGao, Jianping
Methanol, as a renewable fuel, is an attractive option for internal combustion engines. The dual direct injection method is one of the most promising strategies for applying methanol fuel in diesel engines as the flexible injection control enables combustion mode switching. In this study, a 1-L single-cylinder common-rail diesel engine with a compression ratio of 17.4 is retrofitted by installing an additional methanol direct injector with 35 MPa injection pressure. The engine is operated at 1400 rpm, intermediate load, and fixed midpoint combustion phasing of 10 °CA aTDC with a fixed total amount of energy while applying an energy substitution principle with up to 70% energy supplied by methanol. From the experiments, three distinct combustion modes were identified. When early methanol injection timings were selected in the range of 180–60 °CA bTDC, the primary combustion mode was premixed burn. Late injection timings of 10 °CA bTDC to TDC led to heat release rate shapes of the
Zhao, YifanLiu, XinyuKook, Sanghoon
Many cities are built around rivers in the world, and the river-crossing corridors are often their traffic bottlenecks, leading to severe congestions. Changsha is a city divided into two parts by a river with eight river-crossing corridors in China. Aiming at this issue, take Changsha as an example, this study explores developing a precise traffic restriction policy on those river-crossing corridors. First, an investigation is conducted to collect traffic flow data of those corridors. It is found that those corridors generally have serious congestion at peak hours, but their congestion levels vary greatly by corridor and direction. Then, two Greenberg models are developed for the 4-lane and 6 & 8-lane corridors, respectively, to figure out their traffic flow features. Third, a precise traffic restriction policy that balances traffic flows in different corridors is proposed. It would restrict 10% of motor vehicles on those most congested corridors, and the restricted vehicles are
Liu, ChenhuiLuo, QiujuWang, Xingyu
In the highly competitive landscape of the automotive industry, enhancing ride comfort has become a paramount challenge for automakers. To address this challenge, a novel double damper suspension system has been investigated. This system, featuring two single dampers operating collaboratively as an integrated unit, is analyzed with a dual focus: a comprehensive comparison of various control algorithms to identify the one offering superior comfort and the experimental validation of these findings. The modeling process, executed in Simulink, encompasses the representation of pressure, discharge, and force equations, along with the development and testing of multiple control algorithms. The study employs a shock dynamometer, utilizing both the double damper and a single semi-active damper as test subjects in a pseudo-quarter-car test bed setup. Throughout the experimental phase, solenoid actuation in the dampers is guided by specific control logic, utilizing acceleration data for the
Hamedi, BehzadShrikanthan, SudarshanTaheri , Saied
This article aims to conduct a comprehensive performance analysis of various propeller configurations and motors for uncrewed aerial vehicles. The experimental method is used for this study through the performance analysis of the motors and propellers at various conditions. In this study, the test rig has been manufactured specially to test the propeller and motor configuration as per the standard to obtain the thrust at various supplied voltage. This study proved that the increase in the size of propeller leads to increase in the thrust, as well as it can be used for specific applications of the drone like racing drone. It reveals that the maximum diameter of a propeller is 14 inches, which produces the thrust in the range of 2400 g to 361 g depending on motor capacity compared to the other size of the propellers. The novelty of the work is to analyze the performance of propellers and motors for optimization and application of drones through experimental methods. This method can be
Ajay Vishwath, N.C.Balaji, K.Vaishampayan, VibhavPatil, DeepMehta, ParshvaDonde, Gaurangi
For the vibration durability bench test of commercial vehicle batteries, it is essential to have accurate test specifications that exhibit high robustness and reasonable acceleration characteristics. This study evaluates the impact of different battery frame systems on the vibration response of the battery body, as determined by road load spectrum test results of a commercial vehicle battery system. It also confirms the variations in the external environmental load. Utilizing the response spectrum theory, a comprehensive calculation method for the fatigue damage spectrum (FDS) of batteries is developed. The time domain direct accumulation method, frequency domain direct accumulation method, and frequency domain envelope accumulation method are all compared. Analysis of kurtosis and skewness reveals that when the load follows the super-Gaussian distribution characteristics, the time domain direct accumulation method should be used to calculate the fatigue damage spectrum to minimize
Yan, XinGuo, DongniWan, XiaofengSun, JiameiQuan, XinhuiWang, Ying
Dual-fuel (DF) engines enable efficient utilization of a low reactivity fuel (LRF), usually port-injected, and a high reactivity fuel (HRF) provided directly into the cylinder. Ethanol and Camelina sativa oil can be ecologically effective but not fully recognized alternatives for energy production using modern CI engines equipped with a common rail system and adopted for dual fueling. The high efficiency of the process depends on the organization of the combustion. The article describes the premixed dual-fuel combustion (PDFC) realized by dividing the Camelina sativa dose and adjusting its injection timing to the energetic share of ethanol in the DF mixture. The injection strategy of HRF is crucial to confine knock, which limits DF engine operation, but the influence of EGR is also important. The research AVL engine’s dual-fueling tests focused on combustion process modification by the proposed injection strategy and cooled EGR at different substitution rates. For all examined points
Pawlak, GrzegorzSkrzek, TomaszKosiuczenko, KrzysztofPłochocki, PatrykSimiński, Przemysław
There are examples in aerodynamics that take advantage of electric-to-aerodynamic analogies, like the law of Biot–Savart, which is used in aerodynamic theory to calculate the velocity induced by a vortex line. This article introduces an electric-to-aerodynamic analogy that models the lift, drag, and thrust of an airplane, a helicopter, a propeller, and a flapping bird. This model is intended to complement the recently published aerodynamic equation of state for lift, drag, and thrust of an engineered or a biological flyer by means of an analogy between this equation and Ohm’s law. This model, as well as the aerodynamic equation of state, are both intended to include the familiar and time-proven parameters of pressure, work, and energy, analytical tools that are ubiquitous in all fields of science but absent in an aerodynamicists’ day-to-day tasks. Illustrated by various examples, this modeling approach, as treated in this article, is limited to subsonic flight
Burgers, Phillip
Morphology, nanostructure, and composition of soot extracted from the oil sump of different heavy-duty engines operated under dynamometer and field conditions were investigated. Soot characteristics were then compared to a carbon black sample. Soot was extracted from used oil for transmission electron microscopy (TEM) analysis. Energy-dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) analyses were also performed to assess soot composition. Two soot classes, I and II, can be identified based on their appearance under the TEM. Carbon black and class I particles have graphitic structures, while class II samples have a more sludge-like appearance. Similar aggregate sizes were observed among the samples. In all samples, the primary particle size distribution ranges from 16 nm to 22 nm in terms of mean diameter. Differences in the length and tortuosity of the graphitic fringes between the samples were observed. The findings suggest a greater degree of interaction between
Pacino, AndreaLa Rocca, AntoninoCairns, AlasdairFay, Michael W.Smith, JoshuaBerryman, JacquelineFowell, Mark
This article investigates the deformation mechanics of cast iron and its implications for notch analysis, particularly in the automotive industry. Cast iron’s extensive use stems from its cost-effectiveness, durability, and adaptability to various mechanical demands. Gray, nodular, and compacted graphite cast irons are the primary types, each offering unique advantages in different applications. The presence of graphite, microcracks, and internal porosity significantly influences cast iron’s stress–strain behavior. Gray and compacted cast iron display an asymmetrical curve, emphasizing low tensile strength and superior compression performance due to graphite flakes and crack closures. Nodular cast iron exhibits a symmetrical curve, indicating balanced mechanical properties under tension and compression. The proposed simplified macrostructural approach, based on monotonic stress–strain, aims to efficiently capture graphite and crack closure effects, enhancing compressive strength and
LaCourt, CameronLee, Yung-LiGu, Randy
This article introduces an advanced state-of-charge (SOC) estimation method customized for 28 V LiFePO4 (LFP) helicopter batteries. The battery usage profile is characterized by four consecutive current pulses, each corresponding to distinct operational phases on the helicopter: instrument check, key-on, recharge, and emergency power output stages. To establish a precise battery model for LFP cells, the parameters of a second-order equivalent-circuit model are identified as a function of C-rate, SOC, and temperature. Furthermore, the observability of the battery model is assessed using extended Lie derivatives. The signal-to-noise ratio (SNR) of the open-circuit voltage (OCV)–SOC relation is analyzed and employed to evaluate the estimator’s resilience against OCV flatness. The extended Kalman filter (EKF) and the unscented Kalman filter (UKF) are utilized for SOC estimation. The results emphasize the significance of meticulously choosing process and sensor noise covariance matrices to
Gao, YizhaoNguyen, TrungOnori, Simona
The traditional approach to applying safety limits in electromechanical systems across various industries, including automated vehicles, robotics, and aerospace, involves hard-coding control and safety limits into production firmware, which remains fixed throughout the product life cycle. However, with the evolving needs of automated systems such as automated vehicles and robots, this approach falls short in addressing all use cases and scenarios to ensure safe operation. Particularly for data-driven machine learning applications that continuously evolve, there is a need for a more flexible and adaptable safety limits application strategy based on different operational design domains (ODDs) and scenarios. The ITSC conference paper [1] introduced the dynamic control limits application (DCLA) strategy, supporting the flexible application of diverse limits profiles based on dynamic scenario parameters across different layers of the Autonomy software stack. This article extends the DCLA
Garikapati, DivyaLiu, YitingHuo, Zhaoyuan
Test cycle simulation is an essential part of the vehicle-in-the-loop test, and the deep reinforcement learning algorithm model is able to accurately control the drastic change of speed during the simulated vehicle driving process. In order to conduct a simulated cycle test of the vehicle, a vehicle model including driver, battery, motor, transmission system, and vehicle dynamics is established in MATLAB/Simulink. Additionally, a bench load simulation system based on the speed-tracking algorithm of the forward model is established. Taking the driver model action as input and the vehicle gas/brake pedal opening as the action space, the deep deterministic policy gradient (DDPG) algorithm is used to update the entire model. This process yields the dynamic response of the output end of the bench model, ultimately producing the optimal intelligent driver model to simulate the vehicle’s completion of the World Light Vehicle Test Cycle (WLTC) on the bench. The results indicate that the
Gong, XiaohaoLi, XuHu, XiongLi, Wenli
In order to improve the speed control performance of permanent magnet synchronous motor (PMSM) under disturbance, an adaptive reaching law sliding mode control (ASMC) is proposed. The objectives are to accelerate the control stabilization time and reduce chattering in speed control. Based on Lyapunov stability theory, the effectiveness of the scheme is proven. Based on the traditional index reaching law (T_SMRL), the adaptive sliding mode reaching law (ASMRL) introduces the adaptive adjustment terms of chattering, system state, and reaching speed, and uses hyperbolic tangent function instead of sign function. The effectiveness of the ASMRL is proved by theoretical analysis and numerical simulation. Compared with the T_SMRL and improved sliding mode control (I_SMC), the convergence is 33% faster and the chattering is 30% less. In addition, based on the ASMRL, the motor speed control system is established. An extended state observer (ESO) is designed in the surface PMSM (SPMSM) control
Liu, JingangLi, RuiqiLin, HuimingLiu, XianghuanZheng, JianyunYang, Hongmei
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