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 (10,990)

Increasing the Efficiency of Hydrogen Direct Injection Internal Combustion Engines through the Use of Miller Cycles and Water Injection

03-19-01-0001

1/31/2026

Hydrogen-fueled reciprocating engines typically feature reasonable efficiencies and low engine-out emissions but low power density, compromising their utility and economics. Previous hydrogen engine research has found efficiency and anti-knock benefits when using either Miller cycles or water injection. This article therefore studies, for the first time, a directly injected (DI), spark-ignited, heavy-duty, turbocharged and hydrogen-fueled engine operated with both Miller cycles and water injection. Miller cycles, with either early or late intake valve closure, and water injection combine to achieve high engine efficiencies approaching 50%, which is significantly higher than the same engine with standard valve timing. The increased susceptibility of hydrogen autoignition in these Miller cycles is overcome by water injection, which simultaneously increases the charge density, counteracting both lean-burn hydrogen’s and Miller cycles’ commonly observed power loss. This demonstrates that

Mortimer, Joel, Poursadegh, Farzad, Brear, Michael, Yang, Yi

SBD-YOLO: An Efficient Speed Bump Detector for Active Suspension Preview Control

12-09-03-0018

1/28/2026

Speed bump detection through computer vision and deep learning is essential for advancing active suspension preview control and intelligent driving. Although substantial progress has been made in this field, there remains a need to enhance detection accuracy while reducing computational demands. This article introduces a novel single-stage speed bump detector, the Speed Bump Detector Based on You Only Look Once (SBD-YOLO), which utilizes the YOLOv9 architecture for speed bump identification. To better capture the deep global features of speed bumps, we propose an innovative convolutional module—specifically, a lightweight building block designed for efficient feature extraction—named the Aggregated-MBConv. Furthermore, we design a new YOLO backbone by stacking Mobile Inverted Bottleneck Convolution (MBConv) and Aggregated-MBConv modules, which reduces computational cost while enhancing detection accuracy. Additionally, we introduce a Squeeze-aggregated Excitation (SaE) attention

Mao, Ruichi, Wu, Jian, Wu, Yukai, Wang, Huiliang, Li, Jun, Wu, Guangqiang

RDAS: A Shared Control Strategy Considering Real-Time Driving Ability in Driver Takeover Tasks

10-10-02-0014

1/24/2026

Autonomous vehicles require drivers to assume control of the vehicle in situations where the vehicle control system cannot perform its intended task. A shared control-based approach to driving authority transfer can effectively mitigate the driving risks associated with diminished driver capability due to prolonged disengagement, but it may readily precipitate human–machine conflicts—oscillatory steering behavior, excessive driver workload, and unstable control during weight transitions. Addressing the characteristics of driver capability variations during takeover tasks, a shared control strategy incorporating real-time driving ability, termed the real-time driving ability strategy (RDAS), is proposed. Initially, a real-time capability assessment strategy based on an expected steering angle model is developed. By collecting driving data under conditions of adequate driver capability to train an adaptive neuro-fuzzy inference system (ANFIS) neural network, the expected steering angle

Qi, Zhenliang, Liu, Ping, Duan, Haotian, Zhou, Zilong, Huang, Haibo

Crashworthiness of WC19 Wheelchairs in Horizontal Dynamic Aircraft Seating Tests

09-14-02-0001

1/23/2026

At present, commercial air travel rules do not allow people to sit in their own wheelchairs during flight. However, airline seating often does not meet medical needs. In response to current requests to allow this seating option, we researched the crashworthiness and safety of wheelchairs for potential use in aircraft. For motor vehicle travel, many wheelchairs meet voluntary standards for crashworthiness and safety per RESNA WC19. This project assesses whether WC19-compliant wheelchairs can meet FAA aircraft seating standards when secured using 4-point tiedowns. For the FAA horizontal impact testing, computer modeling indicated that a trapezoidal sled pulse was sufficient to represent the more typical triangular pulse, and that due to the flexibility of the tiedown webbing, the effect of the simulated pitch/roll element was minimal. During the initial two horizontal impact tests, fracture of the left front wheelchair caster was observed. The remaining five wheelchairs were tested with

Klinich, Kathleen D., Manary, Miriam A., Boyle, Kyle J., Vallier, Tyler, Orton, Nichole R.

Improve Safety Balance between Women and Men in Frontal Crashes through Parametric Human Modeling and Adaptive Design Optimization

2025-22-0010

1/23/2026

Objective: Previous studies have reported disparity in injuries between male and female drivers in the risk of certain types of injuries in frontal crashes that may be due to a myriad of sex-related differences, including body size, shape, anatomy, or sitting posture. The objectives of this study are 1) to use mesh-morphing methods to generate a diverse set of human body models (HBMs) representing a wide range of body sizes and shapes for both sexes, 2) conduct population-based frontal crash simulations, and 3) explore adaptive restraint design strategies that may lead to enhanced safety for the whole population while mitigating potential differences in injury risks between male and female drivers Method: A total of 200 HBMs with a wide range of body sizes and shapes were generated by morphing the THUMS v4.1 midsize male model into geometries predicted by the statistical human geometry models. Ten male and ten female HBMs were selected for population-based simulations. An existing

Sun, Wenbo, Hu, Jingwen, Lin, Yang-Shen, Boyle, Kyle, Reed, Matthew, Sun, Zhaonan, Hallman, Jason

2024–2025 Reviewers

03-18-08-0051

1/22/2026

2024–2025 Reviewers

Ryan, Tom, Di Blasio, Gabriele

Fixed-Time Lateral Control of Autonomous Vehicles with Prescribed Performance

10-10-02-0012

1/22/2026

Autonomous vehicles regardless of the drivetrain configuration are highly sensitive to disturbances, uncertain dynamic parameters, and modeling errors. Neglecting these factors during trajectory-tracking or lane-keeping can cause the autonomous vehicle (AV) to deviate from its reference path, compromising safety and performance. In this work, a fixed-time prescribed performance backstepping controller integrated with a super-twisting-like algorithm is proposed to ensure fixed-time convergence of trajectory-tracking errors and robust stability under bounded uncertainty factors and external disturbances. A fixed-time prescribed performance approach is utilized to constrain the evolution of lateral and angular tracking errors, thereby limiting the risk of divergence and ensuring control stability. This framework is demonstrated by the Lyapunov-based stability analysis to demonstrate fixed-time stability in an arbitrarily small neighborhood around the origin. The framework is also

Bancel, Baptiste, Kali, Yassine, Nerguizian, Vahé, Saad, Maarouf

A Complex Road Surface Parameter Estimation Method Based on the Fusion Framework of Visual Classifier and Dynamics Observer

10-10-02-0013

1/16/2026

Special vehicles such as off-road vehicles and planetary rovers frequently operate on complex, unpaved road surfaces with varying mechanical parameters. Inaccurate estimation of these parameters can cause subsidence or rollover. Existing methods either lack proactive perception or high precision. This article proposes a fusion framework integrating a visual classifier and a dynamics observer for stable, accurate estimation of road surface parameters. The visual classifier uses an adaptive segmentation system for unpaved roads, leveraging a large-scale vision model and a lightweight network to classify upcoming road surfaces. The dynamics observer employs an online wheel-–ground interaction model using stress approximation, integrating strong tracking theory into an unscented Kalman filter for real-time parameter estimation. The fusion framework performs integration of the classifier and observer outputs at data, feature, and decision levels. An adaptive fading factor and recursive

Zhang, Chenhao, Xia, Guang, Zhang, Yang, Zhou, Dayang, Shi, Qin

Integrated Cooling/HVAC System Design and Control Strategy for Light Fuel Cell Electric Vehicle

14-15-01-0002

1/14/2026

In the recent years, the use of conventional passenger vehicles has been increasingly discouraged, from European-level policies to local municipal regulations, due to the urgent need to reduce greenhouse gas emissions and urban pollution. In response to these challenges, the PRIN2020 project HySUM (Hybrid SUstainable Mobility platform) explores innovative hybrid powertrain solutions for light and heavy quadricycles to achieve near-zero pollutant emissions, focusing on internal combustion engine hybrid electric vehicles and fuel cell hybrid electric vehicles. Taking all these aspects into consideration, this article proposes an integrated solution for cooling/HVAC circuits, to improve energy efficiency and occupants’ comfort, while focusing on proper battery operation, with a recuperator heat exchanger used to recover the available heat at the powertrain output, in order to reduce the HVAC heater energy consumption. The complexity of the circuit requires a specific control logic to be

Lombardi, Simone, Putano Bisti, Chiara, Federici, Leonardo, Pistritto, Antonino, Chiappini, Daniele, Tribioli, Laura

Study the Tool Profile and Rotational Speed on Mechanical Attributes of FSW of Al 6063 Alloy

05-19-03-0023

1/12/2026

Friction stir welding (FSW) of Al 6063 alloy plates of 6 mm thickness was investigated in the present study for exploring the mechanical attributes of the welded joints. The tool profile significantly influences the quality of joints produced by FSW. In the current study, the influence of tool profile and FSW process parameters on the FSW weld characteristics of similar joining of Al 6063 plates has been investigated. The effect of FSW tool rotational speed (TRS) and tool travel speed on the FSW weld properties, mainly microstructure characteristics, microhardness, and ultimate tensile strength (UTS), have been studied. Comparison of two different tool profiles, namely taper and cylindrical tool, has also been examined. The effect of transient temperature distribution has also been studied for varying FSW process parameters. When increasing the tool’s rotational speed from 800 to 1200 rpm at a fixed traverse speed of 80 mm/min, a rise in peak temperature is observed. Conversely

Kumar, Pramod, Kumar, Vikash, Kumar, Gulshan, Arif, Abdul, Prasad, Chitturi Ram, Zubairuddin, M.

Kinetic Modeling and Adaptive Time Stepping for Battery Thermal Runaway Propagation

14-15-01-0003

1/12/2026

0D, quasi-3D, and 3D chemistry solvers with varying degrees of complexity are developed to predict the thermal runaway propagation in battery cells. The 0D solver assumes the system as homogeneous and closed. The quasi-3D solver assumes the system as homogeneous on the selection level and the 3D solver accounts all spatial inhomogeneities in the temperature and composition. Both the quasi-3D and 3D solvers are fully integrated into a computational fluid dynamic (CFD) solver and capable of predicting thermal runaway in multiple battery cells with cell-specific kinetic reaction model. As the modeling complexity increases with each solver, respectively, the accuracy and the simulation time increases. With the large amount of heat and rapid transitions from the onset of thermal runaway, the CFD solvers usually encounter difficulties in predicting the solution accurately and in extreme heat release cases the solver may diverge. A chemical time scale based adaptive time stepping is developed

Chittipotula, Thirumalesha

Determining Absence of Unreasonable Risk: Proposed Criteria for the Evaluation of an Automated Driving System Deployment

12-09-04-0026

1/12/2026

This article provides an overview of how the determination of absence of unreasonable risk can be operationalized. It complements previous theoretical work published by existing developers of automated driving systems (ADS) on the overall engineering practices and methodologies for readiness determination. Readiness determination is, at its core, a risk assessment process. It is aimed at evaluating the residual risk associated with a new ADS deployment. The article proposes methodological criteria to ground the readiness review process for an ADS release. Specifically, it lists 12 readiness criteria connected with system safety, cybersecurity, verification and validation, collision avoidance testing, predicted collision risks, impeded progress, rules of the road compliance, vulnerable road users interactions, high-severity assessment, conservative estimate of severity, risk management, and field safety. The criteria presented are agnostic of any specific ADS technological solution and

Favaro, Francesca Margherita, Schnelle, Scott, Fraade-Blanar, Laura, Victor, Trent, Peña, Mauricio, Webb, Nick, Broce, Holland, Paterson, Craig, Smith, Daniel

Comparison of Vortex Identification Methods in Highly Separated Base Wakes

15-19-01-0002

1/10/2026

In this work, the complex wake flow from a double-slanted Ahmed body with an upper slant of α = 25° and a standard single-slanted Ahmed body with a slant angle of 40° were used to evaluate vortex identification methods for automotive wake flows. Multiple three-dimensional (3D) vortex identification methods including Q−, λ 2−, Ω− criteria, and Liutex method and the two-dimensional (2D) Γ1− criterion were evaluated against the streamline topology as a pseudo-truth model. Of the 3D methods analyzed, none were found to produce wholly satisfactory results. The Q− and λ 2−criteria were plagued by high threshold sensitivity and a failure to separate shear from rotation which led to inconsistent identification of the weak, lower-rotation vortices. While the Ω−criterion was able to mitigate the issues related to threshold sensitivity and separation of shear and rotation by consistently identifying the weak vortices, the identified structure did not align well with the streamline topology

Aultman, Matthew, Duan, Lian

A CNN–LSTM–SVM Framework for Mapping Driving Styles to Adaptive Suspension Modes

10-10-02-0011

1/9/2026

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

Wang, Zhuang, Liu, Jiang, Sun, Haoyu, Yuan, Yinghao, Liu, Jianze, Chen, Xiaofei, Wang, Honglin

Numerical Assessment of High-Cycle Fatigue Behavior of Notched Cast Aluminum Alloy A357-T6 Based on Affected Depth

05-19-03-0024

1/9/2026

This article aims to estimate the high-cycle fatigue (HCF) behavior of a circumferential notched A357-T6 cast aluminum alloy based on the affected depth (AD) approach. This technique is applied as a useful way to anticipate the fatigue life of notched components using the multiaxial fatigue criterion proposed by Crossland. Simulations of the cyclic finite element (FE) calculations in Abaqus involve implementing an elastic–plastic combined Chaboche model. Calculations lead to determining the Kitagawa–Takahashi diagram for this type of defect under the load ratio Rσ = 0.1, showed good agreement with the experimental data. The study provides a clear quantification of the effect of the notch on fatigue resistance. The fatigue limit of the notched specimen decreases by about 16% when the radius of the notch is equal to 3 m. This cast aluminum alloy has revealed a low sensitivity to notches. The notch sensitivity factor (q) was estimated for different defects and conditions, indicating that

Majed, Nesrine, Nasr, Anouar, Youssef, Marwa

Risk-Aware Navigation Framework for Autonomous and Human-Driven Vehicles: Integrating Crash Probability Data for Safer Mobility

12-09-03-0019

1/9/2026

This article presents a system to incorporate crash risk into navigation routing algorithms, enabling safety-aware path optimization for autonomous and human-driven vehicles alike. Current navigation systems optimize travel time or distance, while our approach adds crash probability as a routing criterion, allowing users to balance efficiency with safety. We transform disparate data sources, including traffic counts, crash reports, and road network data, into standardized risk metrics. Because traffic volume data only exist for a small subset of road segments, we develop a solution to project average daily traffic estimates to an entire road inventory using machine learning, achieving sufficient coverage for practical implementation. The framework computes exposure-normalized crash rates weighted by severity and integrates these metrics into routing cost functions compatible with existing navigation algorithms. The key strength of our solution is its scalability. In addition to the

Skaug, Lars, Nojoumian, Mehrdad

Architecting ATA 28 with Model-Based Systems Engineering: Center of Gravity Balance and System Performance

01-18-03-0015

1/7/2026

The fuel management system for a fixed-wing aircraft has been developed and explored with the model-based systems engineering (MBSE) methodology for maintaining the center of gravity (CoG) and analyzing flight safety. The system incorporates high-level modeling abstractions that exploit a mix of behaviors and physical detail resembling real-world components. This approach enables analysis for a multitude of system requirements, verification, and failure scenarios at high simulation speed, which is necessary during system definition. Initially, the CoG is maintained by directly accessing the flight deck valves and pumps in both wings and controlling them through the bang-bang control law. In the refinement phase of the fuel system controller, the manual and individual controls of the valves and pumps are replaced with an autonomous fuel transfer scheme. The autonomous scheme achieves no more than a 20 kg difference in fuel between the wings during normal conditions. In the event of

Zaidi, Yaseen, Michalek, Ota

A Study on Combustion Process in Hydrogen/Hydrotreated Vegetable Oil Dual-Fuel Operation Using Hydroxyl Radical Chemiluminescence

03-18-08-0050

1/7/2026

This study investigated the combustion processes in hydrogen dual-fuel operation using hydrotreated vegetable oil (HVO) and diesel fuel as pilot fuels. The visualizations of hydrogen dual-fuel combustion processes were conducted using hydroxyl radical (OH*) chemiluminescence imaging in an optically accessible rapid compression and expansion machine (RCEM), which can simulate a compression and expansion stroke of a diesel engine. Pilot injection pressures of 40 and 80 MPa and injection quantities of 3, 6 mm3 for diesel fuel and to match the injected energy, 3.14, 6.27 mm3 of HVO were tested. The total excess air ratio was kept constant at 3.0. The RCEM was operated at a constant speed of 900 rpm, with in-cylinder pressure at top dead center (TDC) set to approximately 5.0 MPa. Results demonstrated that using HVO as pilot fuel, compared to diesel fuel, led to shorter ignition delay and combustion duration. OH* chemiluminescence imaging revealed that longer ignition delays observed with

Mukhtar, Ghazian Amin, Une, Naoto, Horibe, Naoto, Hayashi, Jun, Kawanabe, Hiroshi, Hiraoka, Kenji, Koda, Kazuyuki

Modeling and Validating Foreseeable Misuse in Safety of the Intended Functionality: A Case Study of Automated Emergency Braking

12-09-03-0017

12/31/2025

This study presents a structured evaluation framework for reasonably foreseeable misuse in automated driving systems (ADS), grounded in the ISO 21448 Safety of the Intended Functionality (SOTIF) lifecycle. Although SOTIF emphasizes risks that arise from system limitations and user behavior, the standard lacks concrete guidance for validating misuse scenarios in practice. To address this gap, we propose an end-to-end methodology that integrates four components: (1) hazard modeling via system–theoretic process analysis (STPA), (2) probabilistic risk quantification through numerical simulation, (3) verification using high-fidelity simulation, and (4) empirical validation via driver-in-the-loop system (DILS) experiments. Each component is aligned with specific SOTIF clauses to ensure lifecycle compliance. We apply this framework to a case of driver overreliance on automated emergency braking (AEB) at high speeds—a condition where system intervention is intentionally suppressed. Initial

Kang, Do Wook, Kim, Woojin, Jang, Eun Hye, Chang, Mi, Yoon, Daesub, Jang, Youn-Seon

Pathway to Non-Intrusive In-Flight Flow Diagnostics with Filtered Rayleigh Scattering

01-19-01-0001

12/26/2025

A pathway to in-flight application of filtered Rayleigh scattering (FRS) is herein presented, including a viable concept, based on recently published related work. The proposed pathway considers the key technical, operational, and regulatory challenges to enable in-flight measurements using FRS for inlet flow distortion characterization ahead of the aeroengine. Solutions to these challenges are proposed, in particular methods for light delivery, flow imaging and integration of the measurement system in the in-flight environment. This complements the experimental lab-scale demonstration of an FRS concept for flow distortion measurements and provides a route for further exploitation as a diagnostic tool for next-gen aircraft.

Lawson, Nicholas John, Migliorini, Matteo, Doll, Ulrich, Melnikov, Sergey, Steinbock, Jonas, Dues, Michael, Zachos, Pavlos K., Röhle, Ingo, MacManus, David G.

Improving Late Pilot Injection Strategy in Dual-Fuel Diesel/Methane Engines through Supercharging and Hydrogen Enrichment

03-18-08-0049

12/24/2025

In this study, a novel dual-fuel combustion strategy is investigated, employing late pilot injection in diesel–methane engines to improve performance and reduce emissions. The engine was first tested with conventional diesel and methane, exploring a wide range of pilot injection timings, injection pressures, and intake boost pressures. Subsequently, experiments were repeated using a methane/hydrogen blend to assess the influence of hydrogen addition. Results show that, when using only methane, delayed pilot injections have minimal effects on engine performance. In naturally aspirated operation, unburned hydrocarbons and carbon monoxide are reduced, while in supercharged conditions, emissions increase; however, they remain within acceptable limits. Nitrogen oxides and particulate matter reach their lowest levels with delayed injection. Introducing hydrogen reduces engine performance and hydrocarbons and carbon monoxide emissions; notably, it suppresses the typical nitrogen oxides

Carlucci, Antonio Paolo, Strafella, Luciano, Ficarella, Antonio

Toward Enhanced Goods Tracking in Commercial Vehicle Interiors through AI and Sensor Integrations

12-09-02-0016

12/23/2025

The efficient tracking and management of goods within light commercial vehicles (LCVs) is crucial for various industries, particularly craftsmen and parcel delivery services. This article explores the integration of artificial intelligence (AI) and sensor technologies to enhance item tracking and optimize logistical operations in LCVs. Two technological approaches are examined: a Bluetooth-based tracking system and a camera-based parcel identification framework. The Bluetooth-based solution is designed primarily for craftsmen. It employs Bluetooth tags, vehicle connectivity gateways (VCGs), and a centralized server to provide real-time inventory monitoring and prevent tool misplacement. The camera-based system is aimed at parcel carriers. It utilizes AI-driven object detection and pose estimation to localize and identify parcels within the vehicle. Experimental evaluations show that Bluetooth tracking ensures reliability in tool management and the AI-based vision system holds promise

Aslandere, Turgay, Lens, Mathijs, Kirchhof, Jörg Christian, Robberechts, Pieter, Grein, Marcel, Meert, Wannes, Vandewalle, Patrick, Davis, Jesse, Rumpe, Bernhard, Goedemé, Toon

Mixed Aggregation by Comprehensive Normalization Technique–Based Parametric Optimization of Turning of Ti-6Al-4V Alloy in Minimum Quantity Lubrication Environment

05-19-03-0022

12/19/2025

Although Ti-6Al-4V alloy offers high strength-to-weight ratio, corrosion resistance, and biocompatibility properties, its machining is challenging due to low thermal conductivity, high hardness, and chemical reactivity. This study examines turning of Ti-6Al-4V under minimum quantity lubrication (soybean oil). Cutting speed (CS), feed rate (FR), and depth of cut (DOC) are considered as the input parameters. On the other hand, material removal rate (MRR), tool wear rate (TWR), surface roughness (SR), and cutting force (Fc) are treated as the responses. Optimization of the said process is carried out using the mixed aggregation by comprehensive normalization technique (MACONT), a recently developed multi-criteria decision-making (MCDM) method. The optimal parameters are identified as CS = 72.26 m/min, FR = 0.022 mm/rev, and DOC = 0.2 mm, achieving high MRR with low TWR, SR, and Fc. The effects of different turning parameters on the responses are also investigated. Sensitivity analysis

Das, Partha Protim, Sharma, Saurabh, Chakraborty, Shankar

A Comparative Lifecycle Assessment Framework for Automotive Battery Storage Systems

13-07-01-0001

12/19/2025

The transportation sector faces heightened scrutiny to implement sustainable technologies due to market trends, escalating climate change and dwindling fossil fuel reserves. Given the decarbonization efforts underway in the sector, there are now rising concerns over the sustainability challenges in electric vehicle (EV) adoption. This study leverages ISO 14040 Lifecycle Assessment methodology to evaluate EVs, internal combustion engine vehicles (ICEVs), and hybrid electric vehicles (HEVs) spanning cradle-to-grave lifecycle phases. To accomplish this an enhanced triadic sustainability metric (TSM) is introduced that integrates greenhouse gas emissions (GHG), energy consumption, and resource depletion. Results indicate EVs emit approximately 29% fewer GHG emissions than ICEVs but about 4% more than HEVs on the current the US grid, with breakeven sustainability achieved within a moderate mileage range compared to ICEVs. Renewable energy integration on the grid significantly enhances EV

Koech, Mercy Chelangat, Fahimi, Babak, Balsara, Poras T., Miller, John

A Literature Review on Application of Maintenance and Management Strategies for Electric-Vertical Take-Off and Landing Aircraft’s Maintenance, Repair, and Overhaul Organizations

01-18-03-0016

12/18/2025

In the context of emerging technology developed for advanced air mobility concept, its maintenance protocols are not yet mature and existing aviation maintenance systems may not support electric-vertical take-off and landing (e-VTOL) needs. Thus, the operation of e-VTOL aircraft during its deployment stage necessitates the need for qualitative maintenance support. The main purpose of this study is to develop the basic structural principles of the projected new maintenance, repair, and overhaul (MRO) organization for e-VTOL air vehicles, which will support airworthiness through comprehensive maintenance approaches. Thus, the operation of e-VTOL aircraft during its deployment stage necessitates the need for qualitative maintenance support. The importance of the study is to offer standard procedures based on management and maintenance strategies, application of predictive and prescriptive maintenance tools, which pose a significant contribution to ensuring safety, reliability, and cost

Imanov, Tapdig, Bozdereli, Arzu

Farewell and Thank You to Our Founding Editor, Thomas W. Ryan III

03-18-08-0045

12/18/2025

SAE International extends its heartfelt thanks to Tom Ryan for his dedicated work as Editor-in-Chief of the SAE International Journal of Engines from 2008 to 2025. His vision for SAE allowed and encouraged the establishment of our journals program in 2008. As the SAE president that year, he saw the launch of our first journals, assuming the leadership for this journal, as well as establishing the beginning of our other journals. His dedication has helped to establish the journal as an impactful venue for academics and industry researchers alike. Dr. Ryan has been the leading force behind the SAE International Journal of Engines since its inception and is now retiring at the end of 2025 after an impressive tenure with the journal. Because of his instrumental policies and practices, Dr. Ryan will be listed on the journal as Founding Editor in perpetuity. We offer our thanks and great respect for his efforts, dedication, and leadership throughout the years. Dr. Ryan has been working

Martin, Kimberly J.

2024–2025 Reviewers

09-13-02-0014

12/15/2025

2024–2025 Reviewers

Hardy, Warren

Development of an Adaptive Algorithm for the Automatic Emergency Braking System

10-10-01-0008

12/13/2025

Automatic emergency braking (AEB) systems are crucial for road safety but often face performance challenges in complex road and climatic conditions. This study aims to enhance AEB effectiveness by developing a novel adaptive algorithm that dynamically adjusts braking parameters. The core of the contribution is a refined mathematical model that incorporates vehicle-specific correction coefficients and a real-time prediction of the road–tire friction coefficient. Furthermore, the algorithm features a unique driver-style adaptation module to optimize warning times. The developed system was functionally tested on a vehicle prototype in scenarios including dry, wet, and snow-covered surfaces. Results demonstrate that the adaptive algorithm significantly improves collision avoidance performance compared to a non-adaptive baseline, particularly on low-friction surfaces, without introducing excessive false interventions. The study concludes that the proposed adaptive approach is a vital step

Petin, Viktor, Keller, Andrey, Shadrin, Sergey, Makarova, Daria, Antonyan, Akop, Furletov, Yury

2024–2025 Reviewers

13-06-03-0026

12/12/2025

2024–2025 Reviewers

Pilla, Srikanth

Tailpipe NOx Emissions Modeling of a Heavy-Duty Diesel Truck Using Deep Learning Methods

03-18-08-0048

12/11/2025

This study develops deep learning (DL) long–short-term memory (LSTM) models to predict tailpipe nitrogen oxides (NOx) emissions using real-driving on-road data from a heavy-duty Class 8 truck. The dataset comprises over 4 million data points collected across 11,000 km of driving under diverse road, weather, and load conditions. The effects of dataset size, model complexity, and input feature set on model performance are investigated, with the largest training dataset containing around 3.5 million data points and the most complex model consisting of over 0.5 million parameters. Results show that a large and diverse training dataset is essential for achieving accurate prediction of both instantaneous and cumulative NOx emissions. Increasing model complexity only enhances model performance to a certain extent, depending on the size of the training dataset. The best-performing model developed in this study achieves an R2 higher than 0.9 for instantaneous NOx emissions and less than a 2

Shahpouri, Saeid, Jiang, Luo, Koch, Charles Robert, Shahbakhti, Mahdi

Identification of Runway Friction Coefficient Using Extended Kalman Filter

09-13-02-0012

12/11/2025

Aircraft operations during landing or takeoff depend strongly on runway surface conditions. Safe runway operations depend on the tire-to-runway frictional force and the drag offered by the aircraft. In the present research article, a methodology is developed to estimate the braking friction coefficient for varied runway conditions accurately in real-time. To this end, the extended Kalman filtering technique (EKF) is applied to sensor-measured data using the on-ground mathematical model of aircraft and wheel dynamics. The aircraft velocity and wheel angular velocity are formulated as system states, and the friction coefficient is estimated as an augmented state. The relation between the friction coefficient and wheel slip ratio is established using both simulated and actual ground roll data. Also, the technique is evaluated with the simulated data as well as real aircraft taxi data. The accuracy of friction estimation, with and without the measurement of normal reaction force on the

T.K., Khadeeja Nusrath, Singh, Jatinder

Letter from the Guest Editors

04-19-01-0001

12/10/2025

Letter from the Guest Editors

Assanis, Dimitris, Cho, Seokwon, Lawler, Benjamin, Pintor, Dario Lopez

The Technological Concept of a Self-Adjusting Segmented Ceramic Sealing System for a Turboshaft Engine with Isochoric Combustion

03-18-08-0046

12/8/2025

The article presents self-adjusting segmented ceramic seals designed for a novel turboshaft engine operating according to the Humphrey thermodynamic cycle. The sealing system is an integral part of the developed engine concept, which features rotating isochoric combustion chambers. The seals utilize centrifugal force as the sealing force, enabling uniform sealing regardless of thermal conditions and associated deformations. The sealing consists of segments with adjustable dimensions in both circumferential and transverse directions. The sealing elements should be made of Si3N4 ceramic, characterized by high thermal resistance (1300°C) and low thermal expansion (3.2•10−6/°C). The article presents three different variants of sealing systems, differing in terms of the technological possibilities of their manufacturing. Special treatments must be applied to ensure high machining accuracy of the sealing elements. The proposed sealing system is a critical point in the design of an engine

Tarnawski, Piotr

Study of Long-Term Variation of Air Resistance of a Tractor with Semitrailer Using Recorded Weather Data Together with Vehicle Data

02-19-02-0010

12/8/2025

With air resistance being one of the two major energy losses in on-road vehicles (the other one being tire losses) and therefore heavily contributing to the range of battery electric and fuel cell electric vehicles, it is necessary to account for realistic air resistance in a priori assessments like vehicle range estimations, component dimensioning, and system simulations. However, lack of input data tempts analysts to instead assume unrealistic “nominal conditions” throughout—a simplification which usually underestimates the amount of energy actually required to overcome air resistance and completely ignores the fact that varying environmental conditions will lead to significant variances in energy consumption and therefore vehicle range. Using “nominal conditions,” it is thus impossible to assess the robustness of these measures and, therefore, difficult to design robust systems and to perform meaningful trade-off studies. In this study, we show how publicly available data from

Filla, Reno

A Review of the Application and Research Progress of Turbulent Jet Ignition Technology

03-18-08-0047

12/3/2025

For the sustainable development of human society, energy saving, emission reduction, and carbon reduction are urgent challenges to be addressed in the energy industry. As a power device for energy conversion in the transportation sector, the internal combustion engine also needs to enhance its thermal efficiency while cutting pollutant emissions. To meet the current stringent requirements, lean combustion has been widely studied as an effective strategy. However, the ignition difficulty resulting from lean burn needs to be addressed. As a high-energy ignition system, the prechamber turbulent jet ignition can accelerate in-cylinder combustion, thereby enhancing engine efficiency and reducing emissions. Thus, it is considered a promising technology. This review reveals efforts to apply prechamber ignition systems to optimize combustion in the engine characterized by low-carbon fuels and low-emission features. First, this article briefly introduces the evolution of the prechamber

Bai, Xiujuan, Zheng, Dayuan

Robust Lateral Trajectory Tracking of Intelligent Vehicles by Using Fuzzy Adaptive Dynamic Model Predictive Control

10-10-02-0009

12/3/2025

To further improve the smoothness and robustness of lateral trajectory tracking for intelligent vehicles under complex operating conditions, this study proposes and experimentally validates a fuzzy adaptive dynamic model predictive control (FADMPC) strategy on the basis of model predictive control (MPC) framework. Thereinto, a three-degrees-of-freedom vehicle dynamics model serves as the predictive model, and a recursive least-squares algorithm with a forgetting factor is used to estimate tire cornering stiffness, thereby improving model fidelity. A whale optimization algorithm (WOA)–based adaptive horizon scheduler is devised to address the sensitivity of the prediction horizon to vehicle speed and road friction, and a fuzzy regulator adjusts the weight on the lateral displacement error in the objective function in real time. Hardware-in-the-loop tests on jointed and split-road surfaces show that compared with adaptive dynamic MPC, traditional MPC, and linear quadratic regulator, the

Teng, Fei, Jin, Liqiang, Wang, Junnian, Yang, Chen, Fan, Jiapeng, Qiu, Neng, Li, Andong, Zhou, Yanbo

Micromachining through Ultrasonic-Assisted Electrochemical Discharge Process: A Review

05-19-03-0021

12/3/2025

As demand for microcomponents has escalated in diverse areas of automotive, medicine, communications, electronics, optics, biotechnology, and avionics industries, there is a need for hybrid manufacturing techniques that can effectively micromachine hard and brittle materials. Electrochemical discharge machining (ECDM) is an advanced manufacturing process for machining difficult-to-cut materials. With a need for precision and accuracy, tool kinematics is a potential research area in ECDM for achieving geometrical dimensioning and tolerances (GD&T). Therefore, the present study reviews the ultrasonic vibration–assisted ECDM (UA-ECDM) hybrid process and the performance of its process parameters (voltage, electrolyte type and its concentration, electrode material, pulse duration, and amplitude) on the material removal rate (MRR), tool electrode wear (TEW), surface integrity, and difficult-to-cut materials. Also, the present work mentions current problems (debris and bubbles trapped

Prajapati, Mehul S., Lalwani, Devdas I.

TOC

99-07-06-0TOC

12/2/2025

TOC

Tobolski, Sue

Quantifying Naturalistic Changes in Occupant Postures in Belt-Positioning Booster Seats Utilizing Pressure Mats

2025-22-0008

12/2/2025

Belt-positioning booster seats (BPBs) help promote proper seat belt fit for children in vehicles. The effectiveness of BPBs depends on occupant posture, which can be influenced by BPB design features. This study aimed to quantitatively describe how children's postures naturally change over time in BPBs, using pressure mats. Thirty children aged 5 to 12 participated in two 30-minute trials using randomly assigned seating configurations. Five configurations were studied by installing two backless BPBs in vehicle captain’s chairs, varying booster profile (high, low, or no BPB) and armrest presence (with or without BPB/vehicle seat armrests). TekScan 5250 pressure mats were placed on the seating surfaces. Children began in an ideal reference posture, and center of force (COF) data were collected continuously. Additional observations on posture, behavior, and comfort were periodically collected. Mixed models, including effects of seating configuration, time, and volunteer characteristics

Connell, Rosalie, Baker, Gretchen H., Mansfield, Julie A.

2024–2025 Reviewers

14-14-03-0023

11/28/2025

2024-2025 Reviewers

Onori, Simona

2024–2025 Reviewers

02-18-04-0025

11/28/2025

2024–2025 Reviewers

Sandu, Corina

Impinging Shockwave/Boundary Layer Interaction–Induced Separation Mitigation Using Passive Control

01-18-03-0014

11/28/2025

A passive control device to mitigate shock-induced separation in a generic supersonic inlet model is computationally studied. The simulations were based on the Favre-averaged Navier–Stokes equations with the Spalart–Allmaras (SA) turbulence model. The shockwave was generated by an 8° turn supersonic inlet. The Mach number in the inlet was varied between 2.1 and 2.46. The baseline shockwave/boundary layer interaction (SBLI) simulation results compare favorably with experimental data. The passive device, in the form of a splitter plate, eliminates both the separation and flow unsteadiness. The splitter plate causes reduction in the total pressure of the boundary layer at the exit of the inlet due to increased skin friction on the floor and due to wake of the plate.

Olcmen, Semih, Wahidi, Redha, Hegde, Amruthkiran, Datta, Narendra

Full-State Decoupling Motion Control Strategy for Distributed Vehicle via Bayesian Parameter Optimization

10-10-01-0007

11/26/2025

With the rapid development of autonomous driving technology, unmanned ground vehicles (UGVs) are gradually replacing humans to perform tasks such as reconnaissance, target tracking, and search in special scenarios. Omnidirectional mobility based on rapid adjustment of vehicle heading posture enhances the applicability of UGVs in specialized scenarios. Omnidirectional mobility signifies the capability for rapid adjustments to the vehicle’s heading angle, longitudinal velocity, and lateral velocity. Traditional vehicles are constrained by the limitations of under-actuation, which prevents active regulation of lateral movement. Instead, they rely on the coordinated regulation of longitudinal and yaw movements, failing to meet the requirements for omnidirectional mobility. Distributed vehicles featuring steering distributed between the front/rear axles and four-wheel independent drive leverage the over-actuation advantages provided by multi-actuator coordinated control, making them

Chen, Guoying, Dong, Jiahao, Wang, Xinyu, Zhao, Xuanming, Bi, Chenxiao, Gao, Zhenhai, Zhang, Yanping, He, Rong

2024–2025 Reviewers

12-08-04-0039

11/25/2025

2024–2025 Reviewers

Watzenig, Daniel, Fruehling, Terry

Controller Area Network–Based Vehicle Safety System

09-13-02-0011

11/22/2025

This article entails the design, manufacturing, application, testing, and analysis/discussion of a controller area network (CAN)–based vehicle safety system that detects vehicle failure such as brake failure, gear failure, tire blowouts, and other failures that can be monitored using digital or analogue sensors. The aim and objectives are to implement a real-life tire blowout on an Iveco S-Way Euro III and design a system that sends out CAN-based messages using J1939 protocol to the Iveco S-Way Euro III to downshift the gears, retarders, activate the limp mode braking system, activate the hooter, and activate the hazards. The system is split into five sections: (1) detection and activation, (2) gear control system, (3) retarder control system, (4) braking control system, and (5) hooter and hazard control system; while analyzing the: acceleration in the lateral, longitudinal, and vertical acceleration (g) vs. time (s), vehicle speed (km/h), rate of deflation (s), and the steering torque

Rampath, Amaan, Stopforth, Riaan, Proctor-Parker, Craig

Uncertainty Optimization of Vibration Characteristics in Engineering Machinery Powertrain Mounting Systems Using Monte Carlo and Genetic Algorithms

10-10-01-0006

11/22/2025

With the rising demand for high performance and reliability in engineering machinery, the vibration isolation performance and robustness of the powertrain mounting system (PMS) have become critical to overall machine performance. However, during service, rubber mounts are prone to environmental influences, causing significant stiffness deviations that render traditional optimization and analysis methods inadequate. To address this, this article proposes an uncertainty optimization strategy combining Monte Carlo and genetic algorithm (MC-GA), applied to design optimization accounting for stiffness uncertainty due to mount aging, to enhance vibration isolation robustness under large-scale stiffness fluctuations. The study first establishes a Monte Carlo analysis framework based on the statistical characteristics of retired mount stiffness and a dynamic model, systematically evaluating the impact of varying stiffness deviations on vibration characteristics under the original PMS

Xiang, Xingyu, Yi, Hongwei, Hou, Jie, Peng, Cheng, Huang, Haibo, Huang, Xiaorong

Current Research Progress and Future Perspectives of Early Fire Prediction Modeling for Electric Vehicles

14-15-01-0001

11/21/2025

With the wide application of electric vehicles (EVs) around the world, the increase in battery pack energy density and the growing complexity of electrical systems have gradually heightened the risk of vehicle fires. Therefore, achieving efficient and timely fire risk prediction is essential to minimize the probability of fires in EVs. However, the development of EV prediction models requires multidisciplinary integration to address complex safety challenges. This article provides a detailed discussion on the mechanisms and combustion characteristics of EV fires, followed by an investigation into the high-risk factors that trigger such fires. Based on the above content, this article conducts an in-depth analysis of the characteristics of different models for high-risk factors such as batteries, electrical systems, and collision damage, offering insights to bridge the gap between different disciplines. Finally, it explores the future development direction of predictive models for EVs

Shao, Yuyang, Cong, Beihua, Jianghong, Liu

Evaluation of Advanced Powertrain Technologies for Large Agricultural Tractors: Insights on Energy Consumption and Life Cycle Environmental Impact

13-06-03-0025

11/21/2025

This study aims to assess how alternative electrified powertrain technologies affect energy use for agricultural tractors in the Autonomie simulation tool. The goal of this study is also to assess the feasibility and performance of hydrogen internal combustion engines as a suitable alternative for the agricultural tractor powertrains. The energy consumption and efficiencies of alternative powertrains and fuel options are analyzed and compared across a variety of duty cycles using modeling and simulation methodologies. The considered alternative powertrains are series, parallel, power-split hybrid electric, fuel cell, and battery electric powertrains. The alternative fuel and powertrains are evaluated for their energy efficiency as well as their potential to reduce greenhouse gas emissions and improve overall tractor performance in a variety of agricultural applications. Following a methodology developed by Argonne National Laboratory and Aramco Americas, the study applied prospective

Kim, Namdoo, Yan, Ziming, Vijayagopal, Ram, Jung, Jaekwang, He, Xin

Measurement of Road Friction Coefficient with Strain at Tire Sidewall: Verification by Actual Vehicle Driving Experiments

10-10-01-0005

11/20/2025

If road friction coefficient can be measured in a car driving, the performance of advanced driver-assistance systems (ADAS) such as antilock braking system (ABS) and automatic braking systems can be improved. Generally, ADAS uses information obtained from wheel speed sensors, acceleration sensors, and the like. However, it is difficult to measure accurately road friction coefficients with these sensors. Therefore, many studies measured road friction coefficients from strain or deformation in the bottom of a tire (tread), which is the only place to contact with a road surface. However, a sensor installed on the bottom of a tire is easy to peel or damage because greater deformation occurs locally on the bottom of a tire. Therefore, this study develops a method of measuring the road friction coefficient from the strain induced in a tire sidewall. If the tire sidewall can be used, stable measurement can be expected because the sidewall is harder to deform locally than the bottom of a tire

Higuchi, Masahiro, Tachiya, Hiroshi

Effect of Fuel Injection Strategies on Performance, Combustion, and Emission Characteristics of Diesel–Diethyl Ether–Fueled Compression Ignition Engine

03-18-07-0043

11/20/2025

This experimental study compared a blend of diesel–DEE (DEE 40% v/v in diesel) with baseline diesel. This experimental study assesses different fuel injection strategies for controlling the in-cylinder charge stratification, such as single, double, and triple injections. The peak in-cylinder pressure under the partially premixed combustion mode was higher than conventional diesel combustion. Higher in-cylinder pressure with increasing dwell time was observed under triple injections. Retarding pilot injections increased the peak in-cylinder pressure. Conventional diesel combustion mode exhibited the highest brake thermal efficiency and lowest emissions with all injection strategies. A longer dwell time of 12° CA showed higher brake thermal efficiency, nitric oxide, and carbon monoxide emissions, whereas hydrocarbon emissions were lower compared to a shorter dwell time of 6° CA. Hydrocarbon and carbon monoxide emissions increased, but nitric oxide and brake thermal efficiency were

Sonawane, Utkarsha, Agarwal, Avinash Kumar

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