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 (11,008)

Cumulative Prospect Theory Coupled with Multi-Attribute Decision-Making for Path Selection in Hazardous Materials Road Transportation

09-14-02-0002

2/20/2026

Path selection for the transport of hazardous materials (Hazmats) is a multi-facet decision problem that needs to account for multiple factors such as accident risk as well as transportation cost. Most existing literature has modeled the risk of Hazmats transportation as the product of accident loss, and its probability-based expected utility theory, however, could be problematic since such a risk definition does not necessarily reflect the real perceived risk by the decision-maker. This article proposes a novel approach to the path selection of Hazmats transportation based on the cumulative prospect theory (CPT). Specific steps in the decision of path selection are first laid out in the framework of CPT. Value (Loss) functions of accident in Hazmats transportation are then derived, together with the decision weighting function reflecting accident probabilities. For illustration, a case study is conducted using transportation data from a Hazmats transportation firm in Shanghai

Wang, Xulei, Sun, Chunwei

Four-Wheel Independent Steering Vehicle Control under Wheel-Corner Brake Faults

10-10-04-0028

2/18/2026

Wheel-corner brake failures can significantly deteriorate vehicle stability and safety, since unbalanced braking forces may introduce an undesired yaw moment. This work investigates a fault-tolerant control strategy for Active Wheel-Corner Systems, exploiting Four-Wheel Independent Steering (4WIS) to mitigate such effects and preserve vehicle stability when brake actuator malfunctions occur. Unlike many existing approaches, the proposed framework does not require explicit fault detection or quantification as a prerequisite for corrective action, eliminating potential delays and uncertainties associated with fault-diagnosis schemes. A reference model for yaw rate and sideslip angle, incorporating combined longitudinal and lateral dynamics, is proposed, and a Weighted Pseudo-Inverse Control Allocation (WPCA) scheme is employed to distribute corrective actions among the four steering angles according to each tire’s capability, compensating for yaw moment imbalances caused by degraded

Sonnino, Samuel, Melzi, Stefano, Caresia, Pietro, Manzoni, Alessandro, Vaini, Gianluca

On the Modal Characteristics of Motor Stators under Different Interlaminate Fastening Conditions

14-15-01-0005

2/14/2026

The increasing demand for quiet and efficient electric vehicles has highlighted the importance of understanding vibration and noise characteristics of motor stators. Previous studies have extensively modeled electromagnetic excitation and laminated structures, but there has been little experimental evidence clarifying how different interlaminate fastening methods affect vibration modes under comparable conditions. This knowledge gap limits the ability to optimize fastening strategies for noise and vibration control in practical motor design. In this study, laminated stator cores were fabricated with different fastening conditions—bolting, clinching, and welding—and subjected to vibration testing and experimental modal analysis. Natural frequencies, damping ratios, and mode shapes were identified for torsional, circumferential, and breathing modes. The results revealed that the in-plane torsional natural frequencies increase with bolt axial force, while clinching provides additional

Matsubara, Masami, Saito, Akira, Shimada, Shogo, Oishi, Taizan, Furuya, Kohei, Kawamura, Shozo, Tajiri, Daiki

Thoracic Responses of Rear-Seated Midsized Male Surrogates during Frontal Sled Tests

2025-22-0011

2/13/2026

The purpose of this study was to evaluate the thoracic responses of the 50th-percenitle male Hybrid III, THOR, and post mortem human surrogates (PMHS) in the rear seat during frontal sled tests using conventional and advanced restraints in multiple vehicle environments. Twenty-one sled tests were conducted using the Hybrid III and THOR in seven vehicle bucks, and 12 PMHS sled tests were performed using four vehicle bucks. Trends in chest deflections between vehicles and restraint conditions were compared between surrogates. The Hybrid III and THOR thoracic injury risk predictions were compared to the thoracic skeletal damage observed during the PMHS tests. The Hybrid III chest deflections were statistically significantly greater for vehicles equipped with conventional restraints compared to those equipped with advanced restraints. The THOR chest deflections generally followed this trend, but the differences between restraint types were not statistically significant. Hence, the THOR

Albert, Devon L., Bianco, Samuel T., Guettler, Allison J., Boyle, David M., Kemper, Andrew R., Hardy, Warren N.

Optimized Design and Economic Evaluation of a Renewable Hydrogen Refueling Station for Public Transport on Elba Island

14-15-01-0004

2/13/2026

The aim of this study is to develop a methodology to significantly reduce emissions in bus fleet renewal scenarios by investigating both technical and economic aspects. This work presents a case study based on Elba Island, Italy, which investigates optimal solutions for replacing existing Diesel buses through a total cost of ownership analysis. The investigation is carried out for four different potential scenarios: renewing the fleet with Diesel buses, renewing the fleet with electric buses, adopting fuel cell buses, and implementing a hybrid solution. The latter represents a synergistic solution that integrates fuel cell buses with the development of a hydrogen refueling station driven by a proton exchange membrane electrolyzer, unlocking the techno-economic potential of self-producing green hydrogen for bus refueling. The novelty of this study is its integrated methodology that combines a total cost of ownership analysis with a tailored design of a green hydrogen production network

Bove, Giovanni, Sorrentino, Marco, Baldinelli, Arianna, Desideri, Umberto

The Membrane Engine: Concept, Model, and First Results

03-19-01-0003

2/12/2026

This study investigates the feasibility of a novel internal combustion engine (ICE) architecture, termed the membrane engine, in which the conventional piston is replaced by a flexible elastic membrane. Although the concept appears in several patent documents proposing reduced friction, improved sealing, and lower heat losses, no empirical data has been published to support these claims. To the authors’ knowledge, this work presents the first membrane engine built and experimentally tested. The primary aim is to verify whether such an engine can operate as a functional ICE, regardless of its current efficiency or performance level. To support concept validation, a simplified mathematical model was developed to describe the membrane’s deformation and its effect on combustion chamber volume. Unlike conventional piston engines, the membrane introduces a pressure-dependent geometry, enabling a variable compression ratio. The model is not intended to predict performance but to assist in

Allmägi, Roland, Ilves, Risto

Research on Online Learning Architecture for Engine Combustion Prediction on Multi-Platform Simulation

03-19-01-0005

2/11/2026

To address the limitations of conventional offline data-driven models for engine parameter prediction in HIL testing, including poor generalization and inefficient use of supplementary data, this study develops an innovative cross-platform online learning architecture that integrates a pre-trained Python-based Wiebe parameter prediction model with high-fidelity MATLAB/Simulink engine simulation. The proposed framework incorporates five key functional modules (real-time data processing, online regression prediction, performance evaluation, incremental learning optimization, and engine simulation) to enable dynamic adaptation to varying engine conditions through seamless integration of Python’s incremental learning algorithms with Simulink’s simulation environment. By implementing a kth order polynomial decay learning rate strategy, the architecture significantly improves model convergence under limited training conditions while enhancing real-time performance and reliability in HIL

Wei, Mingxin, Shuai, Xiuyun, Wang, Zhaoyu, Zhao, Feiyang, Yu, Wenbin

TOC

99-08-01-0TOC

2/11/2026

TOC

Tobolski, Sue

Measurement of Light Truck Tire Operating Deflection Shapes Using Scanning Doppler Laser Vibrometry: Issues and Insights

10-10-02-0010

2/10/2026

As internal combustion engines are replaced by quieter electric motors in ground vehicles, noise and vibration sources aside from the powertrain have become relatively more important. This is especially true of tires. Measurement of the dynamic vibratory characteristics of tires is critical to understanding their influence on the noise and vibration performance of vehicles, both outside the vehicle body and inside of it. In this work, the normal modes and operating deflection shapes of a Yokohama Geolander A/T light truck tire are measured using traditional modal analysis techniques as well as a non-contact Scanning Laser Doppler Vibrometry (SLDV) approach. Boundary conditions including free, fixed, loaded, and rotating are implemented to the tire and investigated. Rotating conditions are accomplished in a physical chassis dynamometer environment, with the measured tire mounted on the front axle of a Chevrolet Silverado 1500 pickup truck. Modes of vibration and associated natural

Bastiaan, Jennifer M., Chauda, Gaurav, Baqersad, Javad, Gupta, Arjun, Dhami, Kevalya

Research on Active Predictive Speed Control of Dual-Fuel Engine for Hardware Real-Time Applications

03-19-01-0004

2/9/2026

The present article proposes an active observation speed prediction control algorithm architecture for embedded applications, with the aim of addressing the problems of complex operating conditions, strong perturbations, and high control real-time requirements of high-pressure direct injection (HPDI) dual-fuel engines. A nonlinear speed prediction model with diesel and natural gas injection mass as inputs has been established, and the nonlinear model predictive control (NMPC) method is used to realize the optimized control of engine speed. In order to enhance the operational efficiency of the algorithm on the embedded platform, a system has been developed that includes an event triggering mechanism and a warm-start strategy. These mechanisms work in tandem to dynamically adjust the computation cycle. Additionally, a torque reduced-order expansion state observer (RESO) has been integrated to improve the accuracy of perturbation estimation and computational efficiency. The model-level

Yang, Xinda, Li, Yunhua, Chen, Dongdong, Li, Yao, Zhang, Shutao, Zhao, Feiyang, Yu, Wenbin

Experimental Study of Entrainment by Hydrogen-Like Impinging Jets of Various Types in a Confined Compartment

03-19-01-0006

2/9/2026

Recent literature has highlighted significant heat transfer losses and elevated particle formation in direct-injection hydrogen engines, particularly when compared to hydrocarbon fuels such as methane. These challenges are attributed to hydrogen’s unique physicochemical properties, notably its short flame quenching distance and high diffusivity, as well as the interaction between the hydrogen jet and lubricated cylinder surfaces, which promotes lubricant entrainment into the combustion chamber. Consequently, a fundamental understanding of these entrainment mechanisms is a prerequisite for developing engineering strategies to enhance thermal efficiency and mitigate particle formation. The reported study investigates gaseous jet–air interaction in a confined volume to elucidate the influence of injector geometry on jet propagation and air entrainment. Three distinct jet configurations were examined: the wide hollow-cone, the narrow hollow-cone, and the round jets. The jet evolution and

Ben David Holtzer, Ben Binyamin, Tartakovsky, Leonid

Vibration Dynamics of a Half-Car Model Considering Tire–Road Separation

02-19-04-0021

2/9/2026

The vibrating half-car model is used to represent the dynamic behavior of a truck’s dependent suspension system, capturing four degrees of freedom. This research investigates time and frequency responses of vibration behavior of half-car model with possible tire–road separation. This investigation is significant because all previously reported analyses based on the tire-road attachment were incorrect, particularly regarding the tire-road separation phenomenon. The differential equations are extended to enhance the accuracy of the model, incorporating tire–road separation conditions for both wheels. A numerical approach is applied to simulate the vertical and roll dynamics of the system under the separation assumption. The simulation results are validated through experiments conducted using ADAMS View software. Integrating the tire–road separation into the model results in dynamic responses that closely reflect real-world behavior. These findings provide valuable guidance for designing

Nguyen, Quy Dang, Jazar, Reza

Understanding Prevailing Physics in Automotive Aerodynamics Applications—Detached Eddy Simulation vs Reynolds-Averaged Navier–Stokes Approach

02-19-04-0023

2/6/2026

This study presents a structured approach to the aerodynamic evaluation of commercial heavy-duty vehicles by categorizing the underlying flow physics into three primary phenomena: pressure-induced separation, geometry-induced separation, and flow diffusion. Furthermore, the study gives insights into the benefits of Detached Eddy Simulations (DES) over traditional Reynolds-Averaged Navier–Stokes (RANS) approaches by analyzing the flow behavior in cases that correspond to these phenomena. Fundamental insights on pressure and geometry-induced separation were developed through simulations of flow over a sphere and a rectangular cylinder at a Reynolds number of 2.8 × 106. Additionally, flow diffusion was investigated using a coaxial jet interacting with surrounding fluid at a Reynolds number of 2.1 × 104. These cases were analyzed using three turbulence modeling techniques: k-ε, k-ω SST, and DES. To demonstrate the practical relevance of these phenomena, a comprehensive aerodynamic

Sankar, Hari, Holay, Sarang, Ikeda, Masami, Singh, Ramanand

TwinAV: Valve Timing Strategy for Divided Exhaust Periods in Turbocharged Spark-Ignition Engines: A Simulation-Based Evaluation

03-19-01-0002

2/6/2026

Turbocharging is a common and simple method to utilize the exhaust heat of an internal combustion engine. However, conventional turbocharging exhibits the drawback of exhaust gas backpressure and thus increased residual gas mass in the cylinder. A promising concept to increase optimum efficiency is found in the TwinAV concept, which assigns divided exhaust valve cam timing and exhaust manifold configuration. This concept is hypothesized to reduce the static backpressure in the gas exchange loop and the residual exhaust gas amount in the gas exchange phase. In this article, a 1D simulation model was adapted to an existing 4-cylinder gasoline TC engine. Subsequently, the engine concept was applied to this engine model, whereas the focus was to achieve an engine layout for the entire engine speed range applicable for use in passenger vehicles. The results were compared at the full RPM range. Also, a load variation was conducted and benchmarked. The found results show an additional

Gotter, Andreas, Gotter, Alexander

A Data-Driven Method for Typical Landing Gear Structure Optimization Based on Neural Networks

01-19-01-0002

2/6/2026

The landing gear, as a crucial component of an aircraft, is pivotal for maintaining the safety and reliability of air travel. This study introduces a data-driven structural optimization method aimed at mitigating the peak strain on the landing gear’s rocker arm. The initial phase involves selecting nine design variables for parametric modeling to generate an initial dataset. Subsequently, the Maximum Information Coefficient (MIC) technique is used to conduct a parameter sensitivity analysis, enabling the identification and elimination of variables with minimal influence. A comparative analysis between the Genetic Algorithm–Backpropagation Neural Network (GA-BPNN) and BPNN reveals that GA-BPNN has a superior fitting capability on the enhanced dataset. By applying Particle Swarm Optimization (PSO), the optimal solution for GA-BPNN is identified. The implementation of this optimized method results in a 38.16% reduction in peak strain, validating its feasibility and reliability in

Chen, Hu, Shi, Shi, Wang, Meng, Fang, Xingbo, Wei, Xiaohui, Nie, Hong

A Study in System Design and Plumbing Selection Impacts no Steering System Noise in Medium- and Heavy-Duty Commercial Vehicle Hydraulic Steering Systems

02-19-04-0022

2/5/2026

This study investigates noise, vibration, and harshness (NVH) characteristics of hydraulic steering systems in medium- and heavy-duty commercial vehicles due to hydraulic system design. Utilizing on-vehicle and lab environment testing, primarily a pressure sweep test and speed sweep test, to identify sources of NVH. Testing demonstrated a significant impact to perceptible noise and vibration through changes to system and component design. NVH mitigation is accomplished by reducing pressure pulsations, cavitation, and turbulence within the fluid by changing hydraulic plumbing diameter. Reduction in sound pressure level (SPL) averaged 30% with peak reduction of 75%. While optimizing hose diameter is an effective method for controlling NVH in commercial vehicle hydraulic steering systems, additional studies should be conducted in optimizing plumbing materials and routing.

Bari, Praful Rajendra, Kintner, Jason

Improving Semi-Truck Torque Overlay Steering Systems to Boost On-Center Performance: Hardware Design Investigation

02-19-02-0012

2/4/2026

In class 8 semi-trucks, the hydraulic steering gear and torque overlay system are critical components affecting the steering feel design and vehicle control. Transitioning from traditional hydraulic gears to hydraulic gears with torque overlay steering (TOS) systems for increased enhancement of driver comfort is beneficial but has also resulted in drawbacks for on-center steer feel, especially at high vehicle speeds (60+ km/h). This article evaluates the impact of three design mechanisms within hydraulic steering gears of a TOS system that have shown improvement in on-center performance for traditional hydraulic gears. The study compares a standard assembly of TOS, i.e., baseline, and a design-optimized ideal prototype, to evaluate the effectiveness of the three design mechanisms: valve curve performance, on-center friction, and torsion bar stiffness. The two samples underwent high-speed vehicle testing to gather driver feedback and assess potential enhancements to the on-center

Bari, Praful Rajendra, Chaudhuri, Nilankan

Dynamic Stability Enhancement during Emergency Obstacle Avoidance under Inappropriate Driver Operation

10-10-02-0015

2/2/2026

In response to the decline in vehicle stability and the resulting safety risks caused by inappropriate driver operations during high-speed emergency obstacle avoidance, a human–machine cooperative control strategy based on driver operation recognition is proposed. The strategy establishes a vehicle controllability boundary by integrating real-time driver inputs with tire adhesion limits, enabling dynamic evaluation of the influence of operations on system controllability and identification of potential inappropriate operations. On this basis, a control authority allocation mechanism is developed, capable of adaptively adjusting to vehicle states and driver operations. By combining road boundary constraints with vehicle stability envelope constraints, the strategy dynamically regulates the steering angle, ensuring vehicle stability while retaining the driver’s effective intentions as much as possible. Unlike conventional path-tracking or single-envelope control approaches, the proposed

Liu, Yangyi, Zhou, Bing, Wu, Xiaojian, Jiang, Xiaokun, Cui, Qingjia

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

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

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.

Human Detection Capacity of Vehicle Front Sonar Sensors in Light and Small Passenger Cars and Minivan

2025-22-0009

1/22/2026

Sonar sensor systems have been developed to prevent collisions between vehicles and surrounding objects by employing ultrasonic sensors mounted at the front of the vehicle. These systems warn drivers when nearby obstacles are detected. However, relatively few studies have examined the capacity of sonar to detect humans. This study aims to clarify the human detection capacity of front sonar sensors installed in two light passenger cars (LPC-I and LPC-II), one small passenger car (SPC), and one minivan (MNV). The LPC-I, SPC, and MNV were equipped with center and corner sensors, whereas the LPC-II had only corner sensors. Three volunteers—a child, an adult female, and an adult male—participated in the study. Human detectability was assessed using the “maximum detection distance ratio,” defined as the ratio of the maximum detection distance for a volunteer to that for a standard pipe. The results showed that both the center and corner sensors consistently detected front- and side-facing

Matsui, Yasuhiro, Oikawa, Shoko

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.

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

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

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

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.

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

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

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