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.

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System-Level Performance of Torque Vectoring Controllers for Electric Vehicles with In-Wheel Motors10-10-04-00293/13/2026
Torque Vectoring (TV) is a critical control technology for enhancing the vehicle dynamics and stability of electric vehicles equipped with four-wheel-independent-drive (4WID) systems. A central challenge in TV design is managing the trade-off between maximizing handling performance and minimizing energy consumption, a crucial factor for EV range. While numerous advanced TV control strategies have been proposed, a comprehensive and comparative benchmark of foundational controllers evaluated on a platform that captures this trade-off is notably absent from the literature. Among the numerous TV control strategies proposed in literature, they are typically evaluated using simplified vehicle models that neglect the detailed dynamics and efficiency losses of the electric powertrain. This study addresses this gap by presenting a comprehensive comparison of six distinct TV control strategies—PID, LQR, two first-order Sliding Mode Controls (SMC), and two second-order SMCs. The controllers are
Carvalho Pinheiro, Henrique de, Carello, Massimiliana
Time-Step Analysis of Sliding Mesh Rotation Modeling15-19-01-00043/13/2026
The current work analyzes the effect of time-step size on the predictive capability and computational cost of the Sliding Mesh (SM) method for modeling flows around the rotating wheels of a mass-production luxury sport utility vehicle (SUV). Two unsteady turbulence models [Unsteady Reynolds-Averaged Navier–Stokes (URANS) and Delayed Detached Eddy Simulations (DDES)] were tested using time-step sizes ranging from the current recommended time-step size of 1 degree of rotation per time-step (1 D/TS) up to 50 degrees of rotation per time-step (50 D/TS). The flow field predictions compare favorably to the 1 D/TS case for a time-step size as large as 5 D/TS. Using this time-step size leads to a reduction in computational cost of approximately 80% for both unsteady methods. At a time-step of 5 D/TS, the computational cost of the SM method is comparable to the more commonly used Moving Reference Frame (MRF) method. However, drag and flow field predictions by the SM method at this larger time
Struk, Michael, Aultman, Matthew, Disotell, Kevin, Duan, Lian, Bianco, Antonello, Metka, Matthew, Khasdeo, Nitin
Accuracy Requirements for the Road Friction Coefficient Estimation of a Friction-Adaptive Automatic Emergency Braking System as a Software Solution for Integrated Chassis Control Systems10-10-02-00163/10/2026
As part of this work, the accuracy requirements for the road friction coefficient estimation of a friction-adaptive automatic emergency braking (AEB) system are determined using a complex, nonlinear vehicle model. The AEB system varies its trigger distance depending on an estimated value of the road friction coefficient. The accuracy requirements are determined at a driving speed of 40 km/h depending on the severity classification of ISO 26262 in the statistically relevant Euro NCAP test scenario with a stationary target vehicle. MATLAB/Simulink is used as simulation software. The permissible estimation error (difference between estimated value and road friction coefficient) is determined by the severity classification S1 (light and moderate injuries). The results show that the positive permissible estimation error (road friction coefficient is overestimated) must not exceed about 30% of the road friction coefficient to comply with the severity classification S1 of ISO 26262.
Ahrenhold, Tim, Wielitzka, Mark, Binnewies, Tomas, Henze, Roman
Optimal Placement and Sizing of Electric Vehicle Charging Stations and Renewable Distributed Generation on Radial Distribution Network in India Using DIgSILENT Power Factory Software14-15-01-00063/6/2026
The integration of electric vehicle charging station (EVCS) and renewable distribution generation (RDG) in the grid affects the grid voltage, power losses, and system instability in the distribution system, therefore the article presents an approach for optimal placement and sizing of EVCS and RDG using an optimization approach named as modified particle swarm optimization (MOPSO) in radial distribution network (RDN). The efficacy of the optimization approach is demonstrated under both balanced and unbalanced dynamic load conditions in the IEEE 33-bus system. The influence of EVs and RDG on the RDN is analyzed by considering the maximum possible cases, e.g., 13 different scenarios, which replicate real-world scenarios. These results are validated using DIgSILENT Power Factory Software. The proposed research also covers Techno-Economic Assessment using HOMER software, which may enhance visibility of the renewable distribution generation importance in the current scenario.
Kumar, Sonu, Agarwal, Ruchi
Eco-Driving Control for Electric Vehicles with Multi-Speed Transmission: Optimizing Vehicle Speed and Powertrain Operation in Dynamic Environments12-09-03-00212/28/2026
This article presents an eco-driving algorithm for electric vehicles featuring multi-speed transmissions. The proposed controller is formulated as a co-optimization problem, simultaneously optimizing both vehicle longitudinal speed and powertrain operation to maximize energy efficiency. Constraints derived from a connected vehicle–based traffic prediction algorithm are used to ensure traffic safety and smooth traffic flow in dynamic environments with multiple signalized intersections and mixed traffic. By simplifying the complex, nonlinear mixed-integer problem, the proposed controller achieves computational efficiency, enabling real-time implementation. To evaluate its performance, traffic scenarios from both Simulation of Urban MObility (SUMO) and real-world road tests are employed. The results demonstrate a notable reduction in energy consumption by up to 11.36% over an 18 km drive.
He, Suiyi, Sun, Zongxuan
Environmental Impact Analysis of a Multi-Material Body Shell15-19-01-00032/28/2026
In recent times, energy conservation and environmental protection have attracted more and more attention. This research presents a comparative study on the quantitative analysis and comprehensive ranking of the cradle-to-grave environmental benefits of a multi-material body shell across 18 countries. For quantitative analysis of the cradle-to-grave environmental impact of the body shell, life cycle assessment (LCA) was adopted to assess the process of interactions between the environment and human activity. For a comprehensive ranking of the environmental impacts across 18 nations, two modified techniques were used for order preferences by similarity to the ideal solution (TOPSIS) methods, which are improved by the fuzzy analytic hierarchy process (FAHP) and entropy method (EM). The outcomes from these three methodologies; FAHP&EM-TOPSIS, FAHP-TOPSIS, and conventional TOPSIS revealed that the comprehensive environmental benefit rankings of TOPSIS are highly different from the two
Li, Shuhua, Wu, Zongyang, Ji, Xiaoyuan, Tang, Zheng, Wu, Bofu, Rokhsun, Hossain Rahman
Detecting Fuel Adulteration for Otto-Cycle Vehicle Using Onboard Diagnostics Data and Supervised Machine Learning04-19-02-00082/26/2026
Fuel adulteration affects operating costs, vehicle efficiency, and air pollution. Published estimates suggest it accounts for at least 10% of global sales. The Brazilian National Petroleum Agency (ANP) reported noncompliance in about 23% of inspections in 2023, including 4.3% confirmed adulteration. Quality verification requires laboratory equipment, and sensor-based approaches are often inaccessible to end consumers. This article proposes a sensorless (software-only) method that detects water adulteration in hydrated ethanol from standard Onboard Diagnostics (OBD) data using supervised machine learning, enabling on-vehicle fuel quality monitoring without additional hardware. The proposed approach is evaluated on real-world driving data from two production vehicles with three water adulteration levels in hydrated ethanol (0.0%, 2.5%, and 5.0%), achieving 84.85%–95.85% multiclass classification accuracy. These results indicate that software-only, OBD-based monitoring can provide a
Marchezan, Andre Ricardo, Giesbrecht, Mateus
Optimization of Combustion Stability and Fuel Economy for Dedicated Hybrid Engines with High Exhaust Gas Recirculation Rate03-19-02-00082/26/2026
In recent years, the rapid growth of hybrid vehicles has driven the development of dedicated hybrid engines (DHEs) as a key powertrain technology for achieving high thermal efficiency and low emissions. Driven by stringent emissions regulations and demand for improved fuel economy, enhancing thermal efficiency in gasoline engines remains a critical industry challenge. Exhaust gas recirculation (EGR) technology dilutes oxygen in the intake charge, suppresses knock, and optimizes combustion phasing. However, excessive EGR rates compromise combustion stability by inducing elevated cyclic variability and potential misfire, posing challenges in maintaining stable combustion and improving fuel efficiency at high EGR levels. Thus, combustion stability and fuel efficiency optimization in Geely’s DHEs under high EGR conditions was investigated in this article. In this study, a high tumble combustion system was designed to enhance charge motion and promote stable flame propagation. Furthermore
Li, Qiang, Deng, Xiaorong, Ren, Siming, Zhang, Peiyi, Zhu, Yunfeng, Li, Hongzhou, Yan, Pingtao, Gu, Xiangsheng
Human-Like Automatic Braking Algorithm Based on Kinematic Cue: Yield Behavior Analysis and Fuzzy Controller Design10-10-03-00192/25/2026
Pedestrians are among the most vulnerable participants in traffic, particularly when crossing the road. Extensive research has been conducted globally on the yielding behavior analysis of vehicle–pedestrian interaction and the design of automatic vehicle braking systems to mitigate pedestrian casualties. However, few studies have comprehensively addressed lateral risks using implicit kinematic cues in pedestrian–vehicle interactions. Moreover, the design of collision avoidance systems has rarely taken into account driving behavior, along with the pedestrian’s kinematics and crossing behavior. This article presents a human-like automatic braking fuzzy control strategy for pedestrian–vehicle collision avoidance, combining the advantages of professional driver emergency braking behavior and kinematic interaction cues. First, a high-fidelity driving simulator is used to investigate the yielding behavior of pedestrian–vehicle interaction when pedestrians cross the road. Second, the
Zhang, Wenyan, Huang, Xiaorong, Sun, Shulei, Fu, Kairong, Xiong, Qing, Huang, Haibo
Anti-Rollover Strategy for Six-Axis Semi-Trailer Based on Lateral Force Balance02-19-04-00242/24/2026
To address the rollover risk of six-axle semi-trailers due to their large mass, high center of gravity, and multi-axle articulation, a lateral force balance anti-rollover strategy based on the Ackermann steering principle is proposed. By establishing the wheel angle constraint equations for the full-wheel steering system of the six-axle semi-trailer, a rigid-body dynamic model considering the articulation characteristics is developed. The key control and observation parameters are included in the wheel angles, center of gravity lateral offset, yaw angular velocity, sideslip angle, and lateral load transfer rate. An SMC-PID joint controller is designed, in which the third axle steering angle of the tractor is optimized by the SMC controller, and the trailer’s three-axle steering angle tracking control is achieved by the PID controller. The nonlinear accumulation of centrifugal force and dynamic load transfer under high-speed emergency lane change conditions is suppressed by a
Zhang, Qiyuan, Zhang, Lei, Liao, Shengkun, Sun, Jinxu, He, Jing
Development of BYD Flat Engine for Luxury Hybrid Vehicles03-19-02-00072/24/2026
To meet the requirements of luxury hybrid vehicles regarding engine power, torque, size, and NVH performance, BYD independently developed a 2.0 T flat engine. Designs such as increased intake valve lift, widened intake valve profile, swept piston bowl, and extended exhaust backflow region optimized in-cylinder airflow, enabling the BYD flat engine to achieve a maximum power of 180 kW and a peak torque of 380 N·m. This engine is 820 mm in length, 430 mm in width, and 420 mm in height, saving approximately 45% in volume compared to a competitor engine. The lubrication challenges of the flat engine were addressed through the coordinated implementation of a dry sump system, a multifunctional oil pump, and piston ring orientation design. A novel parameterized modal analysis methodology (considering phase and amplitude) was used for optimizing NVH performance. In synergy with the sandwich-type soundproof plates and four-sided acoustic encapsulation, the noise level (1-m sound pressure level
Pan, Shiyi, Zhang, Nan, Wang, Qiang, Liu, Jun, Liu, Jing, Xu, Zhiqin, Zheng, Junli, Li , Cunshuo
Yaw Coordinated Control Based on Fuzzy Control and Stability Region Theory10-10-03-00182/23/2026
Electric vehicle chassis integration control aims to improve vehicle handling and comfort. Previous studies encountered significant practical limitations, such as computational overhead in real-time execution scenarios. Designing effective and efficient algorithms for actuator coordination remains challenging. This article presents a synergetic controller for chassis coordination, combining fuzzy logic and stability region theory. First, the controller targets are the yaw rate and side slip angle, which are obtained from a highly accurate multi-body dynamic model. In addition, based on the generated fuzzy rules, the system calculates the required additional yaw moments for each actuator and optimizes their output. Then, the designed controller can distribute control effort optimally in real-time between braking and rear-wheel steering based on the stability status of the vehicle. Furthermore, a stability factor approach is used to formulate a dynamic safety strategy executed by the
Liao, Yinsheng, Hu, Zhiming, Cheng, Yuanshu, Lin, Ruya, Sun, Yue, Gao, Sixiao, Zhang, Junzhi
Experimental Vibroacoustic Measurement of Thin Steel Panels Coated with Different Liquid-Applied Spray Damping Layer Thickness10-10-02-00172/23/2026
This study investigates the effect of liquid-applied spray damping (LASD) thickness on the vibration and sound radiation of thin steel panels. Although LASD is widely used to enhance structural damping, its influence on radiated sound and the role of coating thickness have not been systematically studied. Five steel panels with varying LASD thicknesses were evaluated using two experimental approaches. An impact-based method in a hemi-anechoic chamber measured the structural mobility and noise transfer functions, while a reciprocal method in a reverberation chamber under acoustic excitation measured the radiated sound power transfer function. A thickness ratio was found beyond which additional LASD thickness yielded diminishing improvements in noise and vibration reductions. The effect of LASD thickness on radiation efficiency was also assessed in both narrowband and one-third octave bands.
Neihguk, David, Suh, Sam, Herrin, David W.
Cumulative Prospect Theory Coupled with Multi-Attribute Decision-Making for Path Selection in Hazardous Materials Road Transportation09-14-02-00022/20/2026
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
Chinese Drivers’ Preference for In-Vehicle Information Display: Insights from a Large-Scale Online Survey12-09-03-00202/20/2026
Integrating intelligent and connected technologies in vehicles has significantly enriched the information environment for drivers, aiding them in making comprehensive driving decisions. However, inadequate information display may lead drivers to miss crucial information or increase their cognitive load, thereby affecting driving safety and user experience. It is essential to study drivers’ preferences for in-vehicle information display, the factors influencing these preferences, and to present information through appropriate modalities and carriers. Drawing on 695 valid questionnaire responses, this study investigates drivers’ preferences for recommendatory, explanatory, alerting, and warning information across three display modalities and six display carriers. A multivariate ordered probability model was further developed to examine the influence of user characteristics on these preferences. The results showed that drivers preferred visual cues over auditory ones, with a selection
He, Gang, Diao, Kai, Luo, Fei Long, Xie, Bingjun, Zhong, Yixin, Qi, Jianping
Four-Wheel Independent Steering Vehicle Control under Wheel-Corner Brake Faults10-10-04-00282/18/2026
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 Conditions14-15-01-00052/14/2026
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
Optimized Design and Economic Evaluation of a Renewable Hydrogen Refueling Station for Public Transport on Elba Island14-15-01-00042/13/2026
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
Thoracic Responses of Rear-Seated Midsized Male Surrogates during Frontal Sled Tests2025-22-00112/13/2026
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.
The Membrane Engine: Concept, Model, and First Results03-19-01-00032/12/2026
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 Simulation03-19-01-00052/11/2026
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
TOC99-08-01-0TOC2/11/2026
TOC
Tobolski, Sue
Measurement of Light Truck Tire Operating Deflection Shapes Using Scanning Doppler Laser Vibrometry: Issues and Insights10-10-02-00102/10/2026
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 Applications03-19-01-00042/9/2026
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 Compartment03-19-01-00062/9/2026
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 Separation02-19-04-00212/9/2026
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
TwinAV: Valve Timing Strategy for Divided Exhaust Periods in Turbocharged Spark-Ignition Engines: A Simulation-Based Evaluation03-19-01-00022/6/2026
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
Understanding Prevailing Physics in Automotive Aerodynamics Applications—Detached Eddy Simulation vs Reynolds-Averaged Navier–Stokes Approach02-19-04-00232/6/2026
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
A Data-Driven Method for Typical Landing Gear Structure Optimization Based on Neural Networks01-19-01-00022/6/2026
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 Systems02-19-04-00222/5/2026
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 Investigation02-19-02-00122/4/2026
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 Operation10-10-02-00152/2/2026
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 Injection03-19-01-00011/31/2026
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 Control12-09-03-00181/28/2026
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 Tasks10-10-02-00141/24/2026
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 Optimization2025-22-00101/23/2026
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 Tests09-14-02-00011/23/2026
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.
2024–2025 Reviewers03-18-08-00511/22/2026
2024–2025 Reviewers
Ryan, Tom, Di Blasio, Gabriele
Human Detection Capacity of Vehicle Front Sonar Sensors in Light and Small Passenger Cars and Minivan2025-22-00091/22/2026
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
Fixed-Time Lateral Control of Autonomous Vehicles with Prescribed Performance10-10-02-00121/22/2026
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 Observer10-10-02-00131/16/2026
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 Vehicle14-15-01-00021/14/2026
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
Kinetic Modeling and Adaptive Time Stepping for Battery Thermal Runaway Propagation14-15-01-00031/12/2026
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 Deployment12-09-04-00261/12/2026
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
Study the Tool Profile and Rotational Speed on Mechanical Attributes of FSW of Al 6063 Alloy05-19-03-00231/12/2026
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.
Comparison of Vortex Identification Methods in Highly Separated Base Wakes15-19-01-00021/10/2026
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
Risk-Aware Navigation Framework for Autonomous and Human-Driven Vehicles: Integrating Crash Probability Data for Safer Mobility12-09-03-00191/9/2026
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
Numerical Assessment of High-Cycle Fatigue Behavior of Notched Cast Aluminum Alloy A357-T6 Based on Affected Depth05-19-03-00241/9/2026
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
A CNN–LSTM–SVM Framework for Mapping Driving Styles to Adaptive Suspension Modes10-10-02-00111/9/2026
Personalized suspension control is pivotal for enhancing vehicle dynamics and ride comfort in intelligent driving systems. This study proposes a driver style recognition model integrating convolutional neural network (CNN) and long–short-term memory (LSTM) networks to match suspension modes with driving styles, validated via a MATLAB–Python co-simulation platform. Time-series multi-source sensor data (throttle position, steering angle, braking intensity) are processed by CNN to extract spatiotemporal features and by LSTM to capture long-term temporal dependencies, enabling accurate classification of aggressive, smooth, and conservative driving styles. A support vector machine (SVM) maps these styles to optimal suspension modes—sport, comfort, or economy—forming an end-to-end framework. Simulation results demonstrate that the CNN–LSTM model achieves an 88% classification accuracy, a 17.33% improvement over the genetic algorithm-optimized backpropagation (GA-BP) model. The SVM-based
Wang, Zhuang, Liu, Jiang, Sun, Haoyu, Yuan, Yinghao, Liu, Jianze, Chen, Xiaofei, Wang, Honglin
A Study on Combustion Process in Hydrogen/Hydrotreated Vegetable Oil Dual-Fuel Operation Using Hydroxyl Radical Chemiluminescence03-18-08-00501/7/2026
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
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