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 (12,058)
2023–2024 Reviewers
El-Sayed, Mohamed
Ongoing research in simulated vehicle crash environments utilizes postmortem human subjects (PMHS) as the closest approximation to live human response. Lumbar spine injuries are common in vehicle crashes, necessitating accurate assessment methods of lumbar loads. This study evaluates the effectiveness of lumbar intervertebral disc (IVD) pressure sensors in detecting various loading conditions on component PMHS lumbar spines, aiming to develop a reliable insertion method and assess sensor performance under different loading scenarios. The pressure sensor insertion method development involved selecting a suitable sensor, using a customized needle-insertion technique, and precisely placing sensors into the center of lumbar IVDs. Computed tomography (CT) scans were utilized to determine insertion depth and location, ensuring minimal tissue disruption during sensor insertion. Tests were conducted on PMHS lumbar spines using a robotic test system for controlled loading in flexion
Burns, Michael R.Caldwell, A. JamesShin, JeesooSochor, Sara H.Kopp, Kevin P.Shaw, GregGepner, BronislawKerrigan, Jason R.
Athletes may sustain numerous head impacts during sport, leading to potential neurological consequences. Wearable sensors enable real-world head impact data collection, offering insight into sport-specific brain injury mechanisms. Most instrumented mouthguard studies focus on a single sport, lacking a quantitative comparison of head impact biomechanics across sports. Additionally, direct comparison of prior studies can be challenging due to variabilities in methodology and data processing. Therefore, we gathered head impact data across multiple sports and processed all data using a uniform processing pipeline to enable direct comparisons of impact biomechanics. Our aim was to compare peak kinematics, impulse durations, and head impact directionality across ice hockey, American football, rugby, and soccer. We found that American football had the highest magnitude of head impact kinematics and observed directionality differences in linear and angular kinematics between sports. On the
Masood, Zaryan Z.Luke, David S.Kenny, Rebecca A.Bondi, Daniel R.Clansey, Adam C.Wu, Lyndia C.
Extreme out-of-position pre-crash postures may need high-force pre-pretensioner (PPT) for effective repositioning (Mishra et al., 2023). To avoid applying a high force on the chest, we hypothesized that in case of these extreme postures the PPT may be activated in the absence of a pre-crash motion as a cautionary measure. Therefore, the aims of this study were: (1) to understand the effect of the PPT in repositioning a forward-leaning occupant in static conditions and (2) to characterize occupants’ kinematic variability during repositioning. Sixteen healthy volunteers (8 males, 8 females, 23.8 ± 4.2 years old) were seated with a 40° forward posture on a vehicle seat and restrained with a 3-point seat belt equipped with a PPT. Two PPT seatbelt conditions were examined: low PPT (100 N) and high PPT (300 N). Head and trunk rearward displacements relative to the initial forward-leaning position at 350 ms from PPT onset were collected with a 3D motion-capture system and compared between
Witmer, MaitlandGriffith, MadelineGraci, Valentina
Prevention and diagnosis of traumatic brain injuries (TBI) are reliant on understanding the biomechanical response of the brain to external stimuli. Finite element models (FEM) and artificial head surrogates are becoming a common method of investigating the dynamic response of the brain to injurious impact and inertial stimuli. The accuracy and validity of these models is reliant on postmortem human subject (PMHS) research to produce biofidelic brain tissue responses. Previous PMHS research has been performed to measure intracranial pressures, displacements, and strains when subjected to impact and inertial loading; however, there remains a need for additional PMHS datasets to improve our understanding of the brain’s dynamics. The purpose of this study is to measure the relative brain–skull displacement in a PMHS specimen when subjected to blunt force impacts. A high-speed X-ray (HSXR) imaging system and embedded radiopaque elastomeric markers were used to record PMHS impacts at
Demiannay, Jean-JacquesRovt, JenniferBrannen, MacKenzieXu, ShengKang, GiaYip, AshleyAzadi, Amir HosseinDehghan, ParisaGoodwin, ShannonTaylor, ReggiePoon, KatherineBrien, SusanHoshizaki, BlaineKarton, ClaraPetel , Oren
Fragility fracture of the hip is a global health concern with generally poor outcomes. Clinical studies have shown prophylactic augmentation of the femur to be a plausible intervention with success in some approaches; however, its use is not yet widespread in the clinical community. We aimed to evaluate the efficacy and clinical safety of prophylactic intramedullary nailing for hip fracture prevention after a fall impact in six cadaveric pelvis–femurs. Post-fall fracture status of the native specimens was determined in a virtual control group built using a validated and peer-reviewed finite element method. A commercially available intramedullary nailing system was prophylactically implanted in all specimens. After augmentation, specimens were subjected to an experimental sideways fall impact and inspected for fracture. Overall, fracture status was unchanged or lowered in severity in the augmented group compared to the native control group. No sign of femur fracture was found in the
Bliven, Emily K.Fung, AnitaBaker, AlexanderHelgason, BenediktGuy, PierreCripton, Peter A.
Exploring the mechanical properties of soft tissues under compressive loading is crucial for understanding their role in automobile incidents. Soft tissues, which serve as cushions or padding between bone and vehicle interiors, significantly influence contact duration and forces, thereby altering incident kinematics and injury. In this investigation, muscle and soft connective tissues from post-mortem human subjects (PMHS) forearms were excised and subjected to compression and indentation testing methods at various rates and strains. Specific samples with higher proportions of muscle were compared against samples without muscle tissues to evaluate the role of compositional changes. Anthropomorphic test device (ATD) upper extremity foam and vinyl–foam composite analog tissues underwent similar testing for comparison. High impact rates simulating those in high-speed automotive collisions were achieved using a custom-built drop tower impactor setup. The results revealed significantly
Dennis, Cole J.Quenneville, Cheryl E.
Drop tower testing was conducted using 50th percentile male PMHS at 15G peak acceleration in a rigid seat, with a seat pan-to-seatback angle of 90°. Subjects were instrumented with 6DOF motion blocks at T1, T4, T12, L3, and S1 to capture detailed vertebral body kinematics. Pressure sensors were also placed throughout the lumbar spine to estimate force in the intervertebral discs from S1-L2. PMHS were restrained using a pilot torso harness attached to the seat at the shoulders and lap belt, both pretensioned to 89 N. Reaction forces were measured in the seat using six-axis loads under the seat pan. Final positioning of the occupant was documented using a FARO arm point probe and laser scanner. To recreate the experimental setup, CAD models of the experimental fixture were meshed using a commercial FE modeling software (Hypermesh) and imported into LS-Dyna for incorporation with the THUMS model. The belt routing tool in LS-PrePost v4.9.12 was used to develop the torso harness and
DeWitt, Timothy R.Marcallini, Angelo M.Bolte IV, John H.Kang, Yun-Seok
Pelvic orientation in vehicles is crucial for preventing injuries and creating safer vehicles and restraint systems. A better understanding of pelvic orientation could provide more accurate anthropomorphic test device (ATD) models of underrepresented populations such as obese individuals, children, and small females. Sonomicrometry is the use of piezoelectric transducers that transmit ultrasound signals to each other to measure the distance between them. These signals may be aggregated using triangulation. In this experiment, ultrasound crystals were secured to the surface of a porcine surrogate to evaluate pelvic movement. This data was then processed using Sonometrics software to generate a 3D model of four static positions and three dynamic tests. The test was validated using a camera and a 3D measurement arm (CMM) to validate XYZ positions. This article discusses how this method could be helpful for developing more accurate ATD models, preventing fatalities in vehicle crashes
Mrozek, AllisonSirhan, KaterenaMacDonald, RobertDannaoui, AbdulMazloum, AishaOchocki, Katarzyna‘Dale’ Bass , Cameron R.
Thorax injuries are a significant cause of mortality in automotive crashes, with varying susceptibility across sex and age demographics. Finite element (FE) human body models (HBMs) offer the potential for injury outcome analysis by incorporating anthropometric variations. Recent advancements in material constitutive models, cortical bone fracture and continuum damage mechanics model (CFraC) and an orthotropic trabecular bone model (OrthoT), offer the opportunity to further improve rib models. In this study, the CFraC and OrthoT material modes, coupled with age-specific material properties, were progressively implemented to the Global Human Body Model Consortium small female 6th rib. Four distinct 6th rib models were developed and compared against sex and age-specific experimental data. The updated material models notably refined the predictions of force–displacement responses, aligning them more closely with the experimental averages. The CFraC model significantly improved the
Corrales, Miguel A.Holcombe, SvenAgnew, Amanda M.Kang, Yun-SeokMarkusic, CraigSugaya, HisakiCronin, Duane S.
Seventeen research posters were prepared and presented by student authors. The posters covered a wide breadth of works-in-progress and recently completed projects. Topics included a variety of body regions and injury scenarios: Biofidelity Corridors of Powered Two-Wheeler Rider Kinematics from Full-Scale Crash Testing Using Postmortem Human Subjects, Meringolo et al. Cervical Vertebral and Spinal Cord Injuries Remain Overrepresented in Rollover Occupants, Al-Salehi et al. The Effect of Surfaces on Knee Biomechanics during a 90-Degree Cut, Rhodes et al. Investigating the Variabilities in the Spinal Cord Injury in Pig Models Using Benchtop Test Model and Ultrasound Analyses, Borjali et al. Relationship between Tackle Form and Head Kinematics in Youth Football, Holcomb et al. Comparing Motor Vehicle Collision Injury Incidence between Pregnant and Nonpregnant Individuals: A Case–Control Study, Levine et al. Development of an Automated Pipeline to Characterize Full Rib Cage Shape
Bautsch, Brian T.Cripton, Peter A.Cronin, Duane
Head injuries account for 15% of snowsport-related injuries, and the majority of head impacts occur against ice or snow, low-friction surfaces. Therefore, this study aimed to evaluate how surface friction affects snowsport helmets’ oblique impact kinematics. Ten helmet models were impacted using an oblique drop tower with a 45-degree anvil and NOCSAE headform, at three locations, two surface friction conditions, and a drop speed of 5.0 m/s. Our findings indicate that friction affects peak linear acceleration, peak rotational acceleration, and peak rotational velocity during helmet impacts, with changes in post-impact rotation and impact response varying by location. Surface friction affects head impact kinematics, underscoring the need for sport-specific lab testing and emphasizing the need for friction-specific and sport-specific testing, particularly for snowsports, where surface conditions like snow and ice can alter kinematics
Stark, Nicole E.-P.Calis, AndrewWood, MatthewPiwowarski, Summer BlueDingelstedt, KristinBegonia, MarkRowson, Steve
Rear-end vehicle collisions may lead to whiplash-associated disorders (WADs), comprising a variety of neck and head pain responses. Specifically, increased axial head rotation has been associated with the risk of injuries during rear impacts, while specific tissues, including the capsular ligaments, have been implicated in pain response. Given the limited experimental data for out-of-position rear impact scenarios, computational human body models (HBMs) can inform the potential for tissue-level injury. Previous studies have considered external boundary conditions to reposition the head axially but were limited in reproducing a biofidelic movement. The objectives of this study were to implement a novel head repositioning method to achieve targeted axial rotations and evaluate the tissue-level response for a rear impact condition. The repositioning method used reference geometries to rotate the head to three target positions, showing good correspondence to reported interverbal rotations
Reis, Matheus SeifCronin, Duane
Human body models have been used for decades to inform efforts in promoting automobile occupant and pedestrian safety. However, many of these models fail to capture the intricacies of individual variability. Cadaveric subjects typically exceed representative age ranges and hence mechanics. Animal subjects typically require specific setups that stray from that which is representative of human crash scenarios. Computational models can only consider so many practical real-world variables. Artificial surrogates, dummies being popular among them, are very popular for reusability and robust data collection. However, even the biomechanically accurate skeletal surrogates available commercially are limited in that they do not consider human variability and skeletal microstructure local variability. The objective of the work herein is to assess computational methods of metastructural variability mimicry by fabrication material. We implement mimicry approaches focusing on bulk isotropic
Hezrony, Benjamin S.C. F. Lopes, PedroBrown, Philip J.
Mitigating both neck and head injuries in the pediatric population relies heavily on improving our understanding of the underlying biomechanics of the pediatric cervical spine. The tensile response for individual motion segments and the whole cervical spine (WCS) has been reported, but there is no data characterizing the intersegmental kinematics of pediatric WCS under axial loading conditions. The structural response of motion segments and WCS provide valuable data for the design and validation of biofidelic physical and computational models for the pediatric population. However, the use of motion segment data to construct WCS response or the use of WCS axial response to accurately characterize intersegmental response may present limitations to accurately modeling the pediatric cervical spine response. In this secondary analysis of the work of Luck et al. (2008, 2013), the fixed-fixed, low load, quasi-static tensile response of the WCS and individual motion segments (O-C2, C4-C5, and
Liu, MirandaLuck, Jason F.
2023–2024 Reviewers
Xu, Peijun
This work aims to define a novel integration of 6 DOF robots with an extrusion-based 3D printing framework that strengthens the possibility of implementing control and simulation of the system in multiple degrees of freedom. Polylactic acid (PLA) is used as an extrusion material for testing, which is a thermoplastic that is biodegradable and is derived from natural lactic acid found in corn, maize, and the like. To execute the proposed framework a virtual working station for the robot was created in RoboDK. RoboDK interprets G-code from the slicing (Slic3r) software. Further analysis and experiments were performed by FANUC 2000ia 165F Industrial Robot. Different tests were performed to check the dimensional accuracy of the parts (rectangle and cylindrical). When the robot operated at 20% of its maximum speed, a bulginess was observed in the cylindrical part, causing the radius to increase from 1 cm to 1.27 cm and resulting in a thickness variation of 0.27 cm at the bulginess location
Srivastava, KritiKumar, Yogesh
Aluminum alloys serve a critical role in the aerospace industry, accounting for a significant amount of commercial aircraft weight. Despite the growing use of composite materials, aluminum remains important in airframe construction due to its lightweight, cost-effectiveness, and high strength potential. Structural integrity is critical in modern engineering, necessitating early diagnosis and localization of damage. To detect the flaws, cracks, and cut-out in the structures, structural health monitoring (SHM) systems are essential, with non-destructive testing (NDT) methodologies playing critical roles. Among these technologies, ultrasonic guided wave testing (UGWT) has gained popularity because of its capacity to propagate over long distances and detect subsurface faults. This article investigates the use of UGWs to identify cut-outs in aluminum plates. The numerical investigation has been carried out using commercially available finite element software Abaqus. The ultrasonic lamb
Rajput, ArunPatil, Vaibhav KailasBhosale, AniketYadav, RiteshGhatge, AdityarajPandey, Anand Ji
With the rapid development of electric vehicles, the need for improved reliability and safety performance of electric vehicle braking systems has become paramount. In response to this demand, a novel direct-drive brake-by-wire actuator based on linear motors was designed to address these challenges. This article presents the structure and principles of the proposed braking actuator. Leveraging the traditional electromechanical brake systems as a foundation, the prototype was modified and fabricated. Additionally, the control and drive system for the braking actuator was established using the TMS320F28335 digital signal processor. Moreover, the current-position dual closed-loop control algorithm was devised to regulate the braking force accurately. Experimental results demonstrate that the direct-drive brake-by-wire actuator exhibits rapid responsiveness and precise braking force modulation, showcasing promising prospects in the field of electric vehicle braking
He, HaitaoGong, XiaoxiangDeng, ZhenghuaLi, TianleWang, XunZhang, HongXu, Rong
2023–2024 Reviewers
Barkey, Mark
Super Duplex Stainless Steels (SDSS) are attracting attentions of the manufacturing industries due to the excellent corrosion resistance to critical corrosion. But SDSS2507 is the hardest to machine with lowest machinability index among DSS family. Moreover, formation of built-up layer (BUL) and work hardening tendency makes it further difficult to machine. Researchers have the conflict in opinions on using wet machining or dry machining using tool coatings. In this investigation SDSS2507 machining is carried out using uncoated and PVD–TiAlSiN-coated tools. The wet and dry machining environment are compared for increase in cutting speed from 170 m/min to 230 m/min. Excellent properties of PVD–TiAlSiN coatings exhibited microhardness of 39 GPa and adhesion strength of 88 N, which outperformed the uncoated tools. Tool life exhibited by coated tools was four times higher than uncoated tools. Wet machining was found to be ineffective when PVD-coated tools are used, exhibiting the same
Sonawane, Gaurav DinkarBachhav, Radhey
Modeling the thermal behavior of dry sliding contacts is complex due to nonlinear thermal boundary conditions and intricate surface interactions. This study reviews and analyzes various thermal models applicable to dry sliding contacts, employing finite element analysis-based numerical simulations for model validation and deeper insights into the system’s physics. The primary goal is to assess the average contact temperatures in sliding pairs of copper-graphite, bronze-graphite, and graphite-graphite. A thermal model is developed, incorporating experimentally measured temperatures taken 2 mm from the contact point and considering the experimental setup’s boundary conditions. The temperature distribution in both the pin and the disc under different loads shows maximum temperatures at the contact point, decreasing with distance both laterally and in depth, reaching a minimum at the outer edges. Results show that the highest temperatures are observed at the contact points, with
Mouadji, YoucefYounes, RassimKhima, SalimBradai, Mohand AmokraneBouchoucha, AliHadidi, Haitham
The dissimilar welding of titanium to steel enables the integration of the advantageous properties of both metals, facilitating the design of lightweight, corrosion-resistant, and high-strength multifunctional composite structures. However, significant differences in their thermophysical properties pose substantial technical challenges in practical welding scenarios, necessitating careful selection of process parameters to enhance the quality and performance of the weld joint. This article establishes a support vector machine (SVM) model with laser power, welding speed, and laser spot diameter as independent variables, and the maximum residual stress and minimum yield strength of the weld joint as dependent variables. To improve prediction accuracy, the SVM model is optimized using the beluga whale optimization (BWO) algorithm. Taking the established model as the objective function, the multi-objective salp swarm algorithm (MSSA) is employed to optimize the laser welding process
Zhu, YubinMeng, XiangliZhang, Xinran
Recent developments in manufacturing techniques and the development of Al7075 metal matrix composites (MMCs) with reinforcements derived from industrial waste have been steadily gaining popularity for aerospace and automobile applications due to their outstanding properties. However, there are still a lot of limitations with these composite materials. A great deal of research has been done to create new Al7075 MMC materials with the use of economic fly ash (FA) that possesses superior mechanical properties, corrosion resistance, density, and cycle cost. This review outlines different synthesis techniques used in the development of Al7075 MMCs using stir casting. Effects of FA along with other reinforcements on the mechanical, wear, machining, and microstructural properties of the composite are also discussed. Finally, a summary of the application of FA-based MMCs and a recap of the previous discoveries and challenges are reported. Future scope and potential areas of application are
Kumar, RandhirMondal, Sharifuddin
Thorax injury remains a primary contributor to mortality in car crash scenarios. Although human body models can be used to investigate thorax response to impact, isolated rib models have not been able to predict age- and sex-specific force-displacement response and fracture location simultaneously, which is a critical step towards developing human thorax models able to accurately predict injury response. Recent advancements in constitutive models and quantification of age- and sex-specific material properties, cross-sectional area, and cortical bone thickness distribution offer opportunities to improve rib computational models. In the present study, improved cortical and trabecular bone constitutive models populated with age-specific material properties, age- and sex-specific population data on rib cross-sectional area, and cortical bone thickness distribution were implemented into an isolated 6th rib from a contemporary human body model. The enhanced rib model was simulated in
Corrales, Miguel A.Cronin, Duane S.Holcombe, SvenAgnew, Amanda M.Kang, Yun-Seok
This study compared modern vehicle and booster geometries with relevant child anthropometries. Vehicle geometries (seat length, seat pan height, shoulder belt outlet height, and roof height) were obtained for 275 center and outboard rear seating positions of US vehicles (MY 2009–2022). Measurements of 85 US boosters (pan height and pan length) and anthropometries of 80 US children between 4–14yo (seated height, thigh length, leg length, and seated shoulder height) were also collected. Comparisons were made between vehicles, boosters, and child anthropometries. Average vehicle seat lengths exceeded child thigh lengths (+9.5cm). Only 16.4% of seating positions had seat lengths less than the child thigh length mean+1SD. Even for children at least 145cm, only 18.8% had thigh lengths greater than the average vehicle seat length. Child thigh lengths were more comparable with average booster seat pan lengths for all multi-mode and high-back designs (-2.0cm) and low-back boosters (+3.1cm). The
Baker, Gretchen H.Connell, Rosalie R.Rhodes, Carrie A.Mansfield, Julie A.
In this article, a novel tuning approach is proposed to obtain the best weights of the discrete-time adaptive nonlinear model predictive controller (AN-MPC) with consideration of improved path-following performance of a vehicle at different speeds in the NATO double lane change (DLC) maneuvers. The proposed approach combines artificial neural network (ANN) and Big Bang–Big Crunch (BB–BC) algorithm in two stages. Initially, ANN is used to tune all AN-MPC weights online. Vehicle speed, lateral position, and yaw angle outputs from many simulations, performed with different AN-MPC weights, are used to train the ANN structure. In addition, set-point signals are used as inputs to the ANN. Later, the BB–BC algorithm is implemented to enhance the path-tracking performance. ANN outputs are selected as the initial center of mass in the first iteration of the BB–BC algorithm. To prevent control signal fluctuations, control and prediction horizons are kept constant during the simulations. The
Yangin, Volkan BekirYalçın, YaprakAkalin, Ozgen
Electromechanical brakes (EMB) are currently coming into focus in the automotive industry. This trend was confirmed in 2022, when a first automotive supplier [1] announced the series production of EMB systems. One major driver is safety, especially if EMB systems are implemented with smart actuators that install redundant electronic control units (ECU) and distributed software [1]. Earlier, the authors have addressed safety mechanisms in EMB actuators [2]. In this article the authors extend their investigation to address safety mechanisms in future EMB central control systems (CCS). Impact of different brake system topologies (X-, H-, centralized) vis-à-vis potential safety mechanisms within communication buses and ECUs is analyzed
Schrade, SimonRöhler, AndreasNowak, XiVerhagen, ArminSchramm, Dieter
This study investigates the flow characteristics in the test section of a model-scale, three-quarters open-jet, closed-loop return wind tunnel equipped with a novel device featuring three subsystems to generate transient yaw, gusts, and turbulence. The effect of each subsystem on the resulting turbulent and unsteady flows is evaluated individually and simultaneously. It is demonstrated that this new turbulence generation system can generate yaw distributions with standard deviations ranging from 2.1° to 8.0°. This replicates a wide range of on-road yaw behavior. Additionally, the subsystems can activate transient yaw events and unsteady gusts. Frequency sweeping was demonstrated to fill a wide range of low-frequency spectra, which helps recreate the on-road flow spectra in wind tunnels. Unsteady gusts of more than 15% of the mean flow velocity were achieved. The active turbulence subsystem generates turbulence levels from a few percent, passively, to over 20% intensity levels actively
Cacho, GemielMarques, JoshuaVan Every, DavidWaudby-Smith, PeterHanson, Ronald
Vehicle light-weighting constitutes a critical component in the automotive sector’s drive to improve fuel economy and reduce greenhouse gas emissions. Among the various options for lightweight materials, thermoplastic foams are distinguished by their durability, low weight, and environmental sustainability. This study explores the manufacturing of novel graphene-filled polypropylene (PP) foam, employing supercritical nitrogen as an eco-friendly substitute instead of conventional chemical foaming agents, and investigated the role of over-molding a solid skin over a foamed core on the flexural strength of the molded component. Our approach is broken down into four distinct investigations—Study I investigated the effect of different graphene content by weight percentage (wt.%), namely 0.1%, 0.5%, and 1%, on flexural properties and foam morphology obtained for 15 wt.% reduction of the PP thermoplastic, thereby helping identify an optimum graphene loading wt.%. Study II broadened the wt
Pradeep, Sai AdityaDeshpande, Amit MakarandShah, BhavikKhan, SaidaFarahani, SaeedSternberg, JamesLi, GangPilla, Srikanth
This article presents experimental investigations and machine learning-based analysis on depositions of super duplex stainless steel (SDSS ER2594) material in wire arc additive manufacturing (WAAM) considering the process parameters namely voltage, wire feed rate, torch travel speed, and gas flow rate. Deposition efficiency and surface height values of the accumulated material were measured to build machine learning models using artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). The developed ANN model could predict the deposition efficiency and surface height with mean absolute deviations (MADs) of 8.9% and 16.1%, respectively. The MAD for prediction of the two responses for ANFIS model was found to be 6.1% and 14.9% as compared to the experimental data. Multi-objective optimization was also performed to obtain optimal solutions to achieve desired deposition results. Mechanical properties and microstructures of the deposited materials with optimal
Kumar, PrakashMondal, SharifuddinMaji, Kuntal
Accurate prediction of the demand for shared bicycles is not only conducive to the operation of relevant enterprises, but also conducive to improving the image of the city, facilitating people’s travel, and solving the balance between supply and demand of bicycles in the region. To precisely predict the demand of shared bicycles, a model combining temporal convolution network (TCN) and bidirectional gating recurrent unit (BiGRU) model is proposed, and the Chernobyl disaster optimizer (CDO) is used to optimize its hyperparameters. It has the ability of TCN to extract sequence features and gated recurrent unit (GRU) to mine time series data and combine the characteristics of CDO with fast convergence and high global search ability, so as to reduce the influence of model hyperparameters. This article selects the shared bicycles travel data in Washington, analyzes its multi-characteristics, and trains it as the input characteristics of the model. In the experiments, we performed comparison
Ma, ChangxiHuang, XiaoyuZhao, YongpengWang, TaoDu, Bo
Automated vehicles (AVs) can get additional information from infrastructure and other vehicles via vehicle-to-everything (V2X) communication. However, how can an AV decide if the surrounding V2X field can reliably provide qualitative, relevant, and trustworthy information? Related research analyzes V2X performance from various angles. However, not only are there identified open gaps in the analysis of loaded channels, but there has also not yet been an effort to design a lightweight metric for rating the quality of the surrounding V2X field. Hence, this work aims to close this existing performance measurement gap and develop a metric for rating the quality of the surrounding V2X field. This article first highlights the gaps identified in performance analysis before closing them with a dedicated measurement campaign. Next, it combines these findings with related research to design a straightforward V2X field rating metric. The resulting V2X field rating metric is a starting point for
Pilz, ChristophKuschnig, LukasSteinberger, AlinaSammer, PeterPiri, EsaCouturier, ChristopheNeumayr, ThomasSchratter, MarkusSteinbauer-Wagner, Gerald
In order to modify both stiffness and damping rates according to various road conditions, this research introduces a pneumatic spring in conjunction with a magnetorheological (MR) fluid damper as a single suspension unit for each wheel in the truck. Preventing weight transfer and improving riding comfort during braking, acceleration, and trajectory prediction are the main objectives. A two-axle truck has been used, consisting of three degrees of freedom for the sprung mass, including vertical, pitch, and roll motions, and four degrees of freedom for the unsprung masses, which have been redesigned according to the different types of springs and dampers. Pneumatic-controlled springs, often referred to as dynamic or classic models, replace laminated leaf springs commonly found in vehicles. Additionally, an MR damper replaces a hydraulic double-acting telescopic shock absorber. These models are studied to evaluate the effect of pneumatic spring parameters on truck dynamics. Pneumatic
Shehata Gad, AhmedEl-Zomor, Haytham M.
Background: Road accident severity estimation is a critical aspect of road safety analysis and traffic management. Accurate severity estimation contributes to the formulation of effective road safety policies. Knowledge of the potential consequences of certain behaviors or conditions can contribute to safer driving practices. Identifying patterns of high-severity accidents allows for targeted improvements in terms of overall road safety. Objective: This study focuses on analyzing road accidents by utilizing real data, i.e., US road accidents open database called “CRSS.” It employs advanced machine learning models such as boosting algorithms such as LGBM, XGBoost, and CatBoost to predict accident severity classification based on various parameters. The study also aims to contribute to road safety by providing predictive insights for stakeholders, functional safety engineering community, and policymakers using KABCO classification systems. The article includes sections covering
Babaev, IslamMozolin, IgorGarikapati, Divya
Automatic emergency braking (AEB) systems play a crucial role in enhancing vehicular safety. Current research predominantly focuses on the longitudinal dynamics of vehicles, utilizing various control algorithms to improve braking effectiveness. However, there has been limited exploration into utilizing wheel deflection as a method to further enhance emergency braking performance. This study aims to contribute by proposing an advanced enhancement of the AEB system through coordinated wheel deflection strategies. In an emergency situation, when the speed of AEB-equipped vehicle drops to the set threshold due to wheel braking, the innovative control system will activate. The vehicle’s coaxial wheels will then execute a counter-deflection maneuver to maximize friction between the tires and the road surface. As a result, this approach reduces braking distance, thereby enhancing vehicle safety. The effectiveness of the proposed control algorithm is validated through combined simulation using
Lai, FeiXiao, HaoHuang, Chaoqun
To enhance vehicle dynamic stability during driving, we developed a three-dimensional phase space model that incorporates the sideslip angle of center of mass, yaw rate, and lateral load transfer rate. This model enabled real-time evaluation and active control of vehicle stability. First, longitudinal and lateral controllers were implemented to ensure precise vehicle trajectory. Second, a hierarchical control strategy was designed to actively manage the desired sideslip angle, yaw rate, and roll angle based on the vehicle’s destabilizing conditions, thereby maintaining the vehicle within a stable state space. We simulated and tested the stability analysis methods and integrated control strategies for both cars and trucks under DLC (double lane change) and CDC (circular driving condition) scenarios using joint simulations with CarSim/TruckSim and Simulink. The proposed integrated stability control strategy, which combined MPC-based trajectory tracking with direct yaw moment control and
Lai, FeiXiao, HaoHuang, Chaoqun
The aim of this work is to develop a composite material and investigate its mechanical characteristics especially suited for automotive applications, and finite element analysis (FEA) of fabricated composite is carried out to examine the mechanical behavior of composites. Utilizing aluminum alloy ingot (LM13) as the matrix material and zirconium diboride (ZrB2) as reinforcement, this work creates composites with improved mechanical and physical properties by accounting impact, tensile, compression, and hardness behavior. FEA is used to examine the increasing behavior of material properties for various volume segments of reinforcement (2.5, 5, 7.5, and 10 wt%) that are supplied to the matrix to determine an acceptable volume percentage of composite based on their input features. In FEA, the impact, tensile, compression, and hardness characteristics of the composite model are investigated by considering von Mises stress, equivalent elastic strain, and total deformation. The experimental
Vijayan, S. N.Chelladurai, Samson Jerold SamuelSaiyathibrahim, A.Infant Jegan Rakesh, A. J.Thriveni, K.Preethi, V.Jatti, Vijaykumar S.Karthik, S.Balaji, K.Saranya, S.
This study provides a detailed energy consumption analysis of two popular micromobility vehicles—an e-scooter and an e-bike—under various conditions, including steady-state and dynamics scenarios. Employing a custom-built data acquisition system, the research tested these vehicles in throttle mode, additionally assessing the e-bike across three pedal-assist levels. The findings reveal that the e-bike operates significantly more efficiently than the e-scooter, with both vehicles demonstrating peak power outputs significantly exceeding their rated values. Furthermore, the study explores how cargo affects the e-bike’s energy use, along with the charging and discharging behaviors of both platforms. Notably, the e-scooter exhibited a considerable battery self-depletion rate, a characteristic not observed on the e-bike
Pamminger, MichaelDuvall, AndrewWallner, Thomas
The primary objective of this article is to study the improvement of machining efficiency of EN-31 steel by optimizing turning parameters using newly developed cutting fluids with different proportions of aloe vera gel and coconut oil, utilizing the Taguchi technique. Furthermore, performance metrics including material removal rate (MRR), surface roughness, and tool wear rate (TWR) were assessed. Analysis of variance (ANOVA) suggested that as cutting speed and feed increase, the MRR is positively influenced, but likewise tool wear is intensified. The surface roughness exhibited a positive correlation with cutting speed, and a negative correlation with increasing both cutting speed and feed. It was found that the maximum MRR value was attained at a cutting speed of 275 m/min, a feed rate of 1.00 mm/rev, and a cutting fluid composition of 30% aloe vera and 70% coconut oil. For the best surface smoothness, it is advisable to adjust the cutting speed to 350 m/min and the feed rate to 0.075
Premkumar, R.Ramesh Babu, R.Saiyathibrahim, A.Murali Krishnan, R.Vivek, R.Jatti, Vijaykumar S.Rane, Vivek S.Balaji, K.
Letter from the Focus Issue Editors
Lakhlani, HardikKumar, VivekWenbin, YuBagga, KalyanGundlapally, SanthoshDi Blasio, GabrieleSplitter, DerekRajendran, Silambarasan
To address the issues of functional conflicts in execution subsystems and the deterioration of control performance due to model parameter uncertainties in the motion control of distributed vehicle by wire, this article proposes an integrated control strategy considering parameter robustness. This strategy aims to compensate for model mismatch, resolve functional conflicts, and achieve motion coordination. Based on the over-actuation characteristics of distributed vehicle by wire, this article constructs the dynamic model and utilizes the tire cornering properties along with phase portraits to delineate the working regions of the execution subsystems. To deal with model parameter uncertainties and mismatch, tube-based model predictive control (tube-based MPC) is applied to the control strategy design, which compensates for model deviations through state feedback and constructs a robust positively invariant set (RPI) to constrain the system state. Correspondingly, the weights of control
Chen, GuoyingBi, ChenxiaoZhao, XuanmingYang, LiunanTang, ZhuoYu, Huili
Forward-facing child restraint systems (FF CRS) and high-back boosters often contact the vehicle seat head restraint (HR) when installed, creating a gap between the back surface of the CRS and the vehicle seat. The effects of HR interference on dynamic CRS performance are not well documented. The objective of this study is to quantify the effects of HR interference for FF CRS and high-back boosters in frontal and far-side impacts. Production vehicle seats with prominent, removeable HRs were attached to a sled buck. One FF CRS and two booster models were tested with the HR in place (causing interference) and with the HR removed (no interference). A variety of installation methods were examined for the FF CRS. A total of twenty-four tests were run. In frontal impacts, HR interference produced small but consistent increases in frontal head excursion and HIC36. Head excursions were more directly related to the more forward initial position rather than kinematic differences caused by HR
Mansfield, Julie A.
2023-2024 Reviewers
Yilmaz, Nadir
For turbocharged engine design, manufacturer-provided turbocharger maps are typically used in simulation analysis to understand key engine performance metrics. Each data point in the turbocharger map is generated by physically testing the hardware or through CFD analysis—both of which are time-consuming and expensive. As such, only a modest set of data can be generated, and each data map must be interpolated and extrapolated to create a smooth surface, which can then be used for engine simulation analysis. In this article, five different machine learning algorithms are described and compared to experimental data for the prediction of Cummins Turbo Technologies (CTT) fixed geometry turbines within and outside of the experimental data range. The results were validated against xxx-provided test data. The results demonstrate that the Bayesian neural networks performed the best, realizing a 0.5%–1% error band. In addition, it is extrapolatable when suitable manually created extra data
Supe, ShreyasNatarajan, BharathShaver, Greg
This study investigates the failure mechanisms of needle bearings within fuel transfer pump assemblies through a comprehensive approach combining endurance testing, detailed inspection, the Dykem blue method, proximity sensors, and finite element analysis (FEA). The findings reveal critical insights into the causes of failure, highlighting significant axial displacement, with a maximum of 0.37 mm measured by proximity sensors. The Dykem technique identified distinct wear patterns across various components, pinpointing areas of high stress and potential failure. Detailed bearing inspections uncovered trunnion damage and abrasive wear, corroborated by FEA, which quantified displacements of 0.144 mm in the x-direction, 0.030 mm in the y-direction, and 0.015 mm in the z-direction. The primary operational factors contributing to bearing failure were contamination and inadequate axial control. These insights are pivotal, as they align with and expand upon established literature on bearing
Kaliyanda, Aneesh
Autonomous vehicle technologies have become increasingly popular over the last few years. One of their most important application is autonomous shuttle buses that could radically change public transport systems. In order to enhance the availability of shuttle service, this article outlines a series of interconnected challenges and innovative solutions to optimize the operation of autonomous shuttles based on the experience within the Shuttle Modellregion Oberfranken (SMO) project. The shuttle shall be able to work in every weather condition, including the robustness of the perception algorithm. Besides, the shuttle shall react to environmental changes, interact with other traffic participants, and ensure comfortable travel for passengers and awareness of VRUs. These challenging situations shall be solved alone or with a teleoperator’s help. Our analysis considers the basic sense–plan–act architecture for autonomous driving. Critical components like object detection, pedestrian tracking
Dehghani, AliSalaar, HamzaSrinivasan, Shanmuga PriyaZhou, LixianArbeiter, GeorgLindner, AlisaPatino-Studencki, Lucila
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