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In the modern automotive industry, improving fuel efficiency while reducing carbon emissions is a critical challenge. To address this challenge, accurately measuring a vehicle’s road load is essential. The current methodology, widely adopted by national guidelines, follows the coastdown test procedure. However, coastdown tests are highly sensitive to environmental conditions, which can lead to inconsistencies across test runs. Previous studies have mainly focused on the impact of independent variables on coastdown results, with less emphasis on a data-driven approach due to the difficulty of obtaining large volumes of test data in a short period, both in terms of time and cost. This paper presents a road load energy prediction model for vehicles using the XGBoost machine learning technique, demonstrating its ability to predict road load coefficients. The model features 27 factors, including rolling, aerodynamic, inertial resistance, and various atmospheric conditions, gathered from a
Song, HyunseungLee, Dong HyukChung, Hyun
With the rapid development of intelligent connected vehicles, their open and interconnected communication characteristics necessitate the use of in-vehicle Ethernet with high bandwidth, real-time performance, and reliability. DDS is expected to become the middleware of choice for in-vehicle Ethernet communication. The Data Distribution Service (DDS), provided by the Object Management Group (OMG), is an efficient message middleware based on the publish/subscribe model. It offers high real-time performance, flexibility, reliability, and scalability, showing great potential in service-oriented in-vehicle Ethernet communication. The performance of DDS directly impacts the stable operation of vehicle systems, making accurate evaluation of DDS performance in automotive systems crucial for optimizing system design. This paper proposes a latency decomposition method based on DDS middleware, aiming to break down the overall end-to-end latency into specific delays at each processing stage
Yu, YanhuaLuo, FengRen, YiHou, Yongping
On-board diagnosis (OBD) of gasoline vehicle emissions is detected by measuring the fluctuations of the rear oxygen sensor due to the time-dependent deterioration of the oxygen storage capacity (OSC) contained in the automotive catalyst materials. To detect OBD in various driving modes of automobiles with an order of magnitude higher accuracy than before, it is essential to understand the OSC mechanism based on fundamental science. In this study, time-resolved dispersive X-ray absorption fine structure (DXAFS) using synchrotron radiation was used to carry out a detailed analysis not only of the OSC of ceria-based complex oxides, which had previously been roughly understood, but also of how differences in design parameters such as the type of precious metals, reducing gases (CO and H2), detection temperatures, and mileages (degree of deteriorations) affect the OSC rate in a fluctuating redox atmosphere. A fundamental characteristic was clearly demonstrated in ceria-based complex oxides
Tanaka, HirohisaMatsumura, DaijuUegaki, ShinyaHamada, ShotaAotani, TakuroKamezawa, SaekaNakamoto, MasamiAsai, ShingoMizuno, TomohisaTakamura, RikuGoto, Takashi
Electric vehicles (EVs) are particularly susceptible to high-frequency noise, with rubber eigenmodes significantly influencing these noise characteristics. Unlike internal combustion engine (ICE) vehicles, EVs experience pronounced variations in dynamic preload during torque rise, which are substantially higher. This dynamic preload variation can markedly impact the high-frequency behaviour of preloaded rubber bushings in their installed state. This study investigates the effects of preload and amplitude on the high-frequency dynamic performance of rubber bushings specifically designed for EV applications. These bushings are crucial for vibration isolation and noise reduction, with their role in noise, vibration, and harshness (NVH) management being more critical in EVs due to the absence of traditional engine noise. The experimental investigation examines how preload and excitation amplitude variations influence the dynamic stiffness, damping properties, and overall performance of
Hazra, SandipKhan, Arkadip Amitava
Abstract The technological advancements in the automotive industry have seen a significant leap with the introduction of automated driving system (ADS)-equipped Vehicles (AVs), with potential for enhanced safety, efficiency, and mobility. As the development of an AV transitions from the stages of conceptual design to deployment, assessing the maturity of the technology through a structured framework is crucial. This paper proposes the adaptation of the Technology Readiness Level (TRL) framework originally developed by NASA (and adopted widely in a variety of industries) to the AV industry to provide a consistent, understandable, and transparent method to describe an AV product’s stage of development. The TRL framework is mated to the existing safety case framework (SCF) developed in the Automated Vehicle – Test and Evaluation Process (AV-TEP) Mission, a collaboration between Science Foundation Arizona and Arizona State University. The claim that the AV is ready to transition from one
Swaminathan, SunderWishart, JeffreyZhao, JunfengRusso, BrendanRahimi, Shujauddin
Apple’s mobile phone LiDAR capabilities can be used with multiple software applications to capture the geometry of vehicles and smaller objects. The results from different software have been previously researched and compared to traditional ground-based LiDAR. However, results were inconsistent across software applications, with some software being more accurate and others being less accurate. (Technical Paper 2023-01-0614. Miller, Hashemian, Gillihan, Benes.) This paper builds upon existing research by utilizing the updated LiDAR hardware that Apple has added to its iPhone 15 smartphone lineup. This new hardware, in combination with the software application PolyCam, was used to scan a variety of crashed vehicles. These crashed vehicles were also scanned using a FARO 3D scanners and Leica RTC 360 scanners, which have been researched extensively for their accuracy. The PolyCam scans were compared to FARO and Leica scans to determine accuracy for point location and scaling. Previous
Miller, Seth HigginsStogsdill, MichaelMcWhirter, Seth
In a three-phase voltage source inverter, in order to prevent the direct short circuit of the upper and lower tubes of the bridge arm and ensure the normal operation of the inverter, microsecond-level dead time needs to be added when the power devices are turned on and off. However, due to the dead-time effect, slight distortion may occur in the inverter within the modulation period, and this distortion will eventually lead to harmonic components in the output current after accumulation, thereby generating torque ripple. Against the above background, implementing dead-time compensation strategies is very important. To compensate for the voltage error caused by the dead-time effect, current polarity determination is required first. Then, the dead time is compensated, thereby indirectly compensating for the voltage error caused by the dead-time effect. Regarding the dead-time compensation time, without changing the hardware, this paper proposes a solution to turn off the dead-time
Jing, JunchaoZhang, JunzhiZuo, BotaoLiu, YiqiangYang, TianyuZhu, Lulong
Electric vehicles (EVs) are gaining popularity due to their zero tailpipe emissions, superior energy efficiency, and sustainable nature. EVs have various limitations, and crucial one is the occurrence of thermal runaway in the battery pack. During charging or discharging condition of battery pack may result in thermal runaway condition. This promotes the requirement of effective cooling arrangement in and around the battery pack to avoid localized peak temperature. In the present work, thermal management of a 26650 Lithium iron phosphate (LFP) cell using natural convection air cooling, composite biobased phase change material (CBPCM) and its combination with copper fins is numerically investigated using multi-scale multi dimension - Newman, Tiedenann, Gu and Kim (MSMD-NTGK) battery model in Ansys Fluent at an ambient temperature of 306 K. Natural convection air cooling was found effective at discharge rates of 1C to 3C, maintaining cell temperature below the safe limit of 318 K for 80
Srivastav, DurgeshPatil, Nagesh DevidasShukla, Pravesh Chandra
Neck injury is one of the most common injuries in traffic accidents, and its severity is closely related to the posture of the occupant at the time of impact. In the current era of smart vehicle, the triggered AEB and the occupant's active muscle force will cause the head and neck to be out of position which has significant affections on the occurrence and severity of neck injury responses. Therefore, it is very important to study the influences of active muscle force on neck injury responses in in frontal impact with Automatic Emergency Braking conditions. Based on the geometric characteristics of human neck muscles in the Zygote Body database, the reasonable neck muscle physical parameters were obtained firstly. Then a neck finite element model (FEM) with active muscles was developed and verified its biofidelity under various impact conditions, such as frontal, side and rear-end impacts. Finally, using the neck FEM with or without active muscle force, a comparative study was
Junpeng, XuGan, QiuyuJiang, BinhuiZhu, Feng
This study investigates the influence of magnetorheological (MR) dampers in semi-active suspension systems (SASSs) on ride comfort, vehicle stability, and overall performance. Semi-active suspension systems achieve greater flexibility and efficacy by combining MR dampers with the advantages of active and passive suspension systems. The study aims to measure the benefits of MR dampers in improving ride comfort, vehicle stability, and overall system performance. The dynamic system model meets all required performance criteria. This study demonstrates that the proposed artificial intelligence approach, including a fuzzy neural networks proportional-integral-derivative (FNN-PID) controller, significantly enhances key performance criteria when tested under various road profiles. The control performance requirements in engineering systems are evaluated in the frequency and time domains. A quarter-car model with two degrees of freedom (2 DOF) was simulated using MATLAB/Simulink to assess the
M.Faragallah, MohamedMetered, HassanAbdelghany, M.A.Essam, Mahmoud A.
The problem of monitoring the parametric failures of a traction electric drive unit consisting of an inverter, a traction machine and a gearbox when interacting with a battery management system has been solved. The strategy for solving the problem is considered for an electric drive with three-phase synchronous and induction machines. The drive power elements perform electromechanical energy conversion with additional losses. The losses are caused by deviations of the element parameters from the nominal values during operation. Monitoring gradual failures by additional losses is adopted as a key concept of on-board diagnostics. Deviation monitoring places increased demands on the information support and accuracy of mathematical models of power elements. We take into account that the first harmonics of currents and voltages of a three-phase circuit are the dominant energy source, higher harmonics of PWM appear as harmonic losses, and mechanical losses in the rotor and gearbox can be
Smolin, VictorGladyshev, SergeyTopolskaya, Irina
The rapid development of intelligent and connected vehicles is transforming them into data-rich information carriers, which generate and store vast amounts of sensitive information. However, the frequent sharing of resources within these vehicles poses substantial risks to user privacy and data security. Should sensitive resources be accessed maliciously, the consequences could be severe, leading to significant threats to the safety, property, and reputation of both drivers and passengers. To address these risks, this paper proposes an adaptive risk-based access control with Trusted Execution Environment (TEE) specifically designed for vehicles, aimed at managing and restricting access permissions based on risk assessments. Firstly, this paper designs an adaptive risk model in accordance with ISO/SAE 21434, taking into account factors such as the security levels of subjects and objects, context, and the risk history of subjects to separately quantify threats and impacts. By adjusting
Luo, FengLi, ZhihaoWang, JiajiaLuo, Cheng
Optimizing engine mounting systems is a complex task that requires balancing the isolation of vehicle vibrations with controlling powertrain movement within a limited dynamic envelope. Six Degrees of Freedom (6DOF) optimization is widely used for mounting stiffness and location optimization. This study investigates the application of various optimization algorithms for 6DOF analysis in engine mount design, where the system’s stochastic behaviour and probabilistic characteristics present additional challenges. Selecting an appropriate optimization framework is essential for achieving accurate and efficient NVH results. Recent advancements in research have introduced several 6DOF optimization algorithms to determine the optimal stiffness and location of engine mounts. The study evaluates a range of optimization methods, including Simultaneous Hybrid Exploration that is Robust, Progressive and Adaptive (SHERPA), Quadratic Programming (QP), Genetic Algorithm (GA), Particle Swarm
Hazra, SandipKhan, Arkadip
Many methods have been proposed to accurately compute a vehicle’s dynamic response in real-time. The semi-recursive method, which models using relative coordinates rather than dependent coordinates, has been proven to be real-time capable and sufficiently accurate for kinematics. However, not only kinematics but also the compliance characteristics of the suspension significantly impact a vehicle’s dynamic response. These compliance characteristics are mainly caused by bushings, which are installed at joints to reduce vibration and wear. As a result, using relative or joint coordinates fails to account for the effects of bushings, leading to a lack of compliance characteristics in suspension and vehicle models developed with the semi-recursive method. In this research, we propose a data-driven approach to model the compliance characteristics of a double wishbone suspension using the semi-recursive method. First, we create a kinematic double wishbone suspension model using both the semi
Zhang, HanwenDuan, YupengZhang, YunqingWu, Jinglai
In the pre-crash emergency braking scenario, the occupant inside the vehicle will move forward due to inertia, deviating from the standard upright seating position for which conventional restraint systems are designed. Previous studies have mainly focused on the influence of out-of-position (OOP) displacement on occupant injuries in frontal collisions, and provided solutions such as active pretensioning seatbelts (APS). But little attention has been paid to the influence of OOP on whiplash injury during a subsequent rear-end collision. To investigate the forward OOP impact on whiplash injuries and the effectiveness of APS in this accident scenario, a vehicle interior model with an active human body model (AHBM) was setup in the MADYMO simulation platform. Different braking strengths (0.8g and 1.1g), APS triggering times (from 0.2s before to 0.2s after the braking initiation) and pretensioning forces (from 100N to 600N) were input to the simulation matrix. The occupant’s forward OOP
Fei, JingQiu, HangWang, PeifengLiu, YuCheng, James ChihZhou, QingTan, Puyuan
The integration of mobile device data in accident/crash/collision reconstruction methodologies offers significant potential in analyzing collision events. This study evaluates the utility of iPhone-recorded data, specifically Global Navigation Satellite System (GNSS) position and speed data, along with Coordinated Universal Time (UTC) based time and date information associated with application usage and device activity events. By conducting controlled tests, the accuracy, precision, and reliability of iPhone GNSS data were compared against high-accuracy reference systems, including a Racelogic VBox Video HD2 25 Hz GPS data logger and VBox Sport 25 Hz GPS data logger. The synchronicity between recorded app events and device activities with physical events was also analyzed to assess the temporal resolution of the data. Results highlight the strengths and limitations of iPhone data for reconstructing crash events, including potential discrepancies in GNSS accuracy under varying
Burgess, ShanonPhy, LanceLevan, Matthew
It is becoming increasingly common for bicyclists to record their rides using specialized bicycle computers and watches, the majority of which save the data they collect using the Flexible and Interoperable Data Transfer (.fit) Protocol. The contents of .fit files are stored in binary and thus not readily accessible to users, so the purpose of this paper is to demonstrate the differences induced by several common methods of analyzing .fit files. We used a Garmin Edge 830 bicycle computer with and without a wireless wheel speed sensor to record naturalistic ride data at 1 Hz. The .fit files were downloaded directly from the computer, uploaded to the chosen test platforms - Strava, Garmin Connect, and GoldenCheetah - and then exported to .gpx, .tcx and .csv formats. Those same .fit files were also parsed directly to .csv using the Garmin FIT Software Developer Kit (SDK) FitCSVTool utility. The data in those .csv files (henceforth referred to as “SDK data”) were then either directly
Sweet, DavidBretting, Gerald
The Autocycle is a style of vehicle that most often utilizes a reverse-tricycle design with two front wheels and a single rear wheel. Modern autocycles in the United States are often utilized in a recreational role. This work presents physical measurements of two modern autocycles for use in accident reconstruction and pursues a deeper understanding of the unique attributes and handling associated with these vehicles. Vehicles were used to measure physical properties and subjected to cornering tests presented herein, and the data is compared to that for a conventional automobile. Observations on tire scuff marks are made from cornering tests unique to these vehicles. Strengths and challenges with this type of vehicle design are presented for various use cases as compared to conventional automobiles. Data and knowledge from this study are published to aid accident reconstruction efforts.
Warner, WyattSwensen, GrantWarner, Mark
Electric vehicles (EVs) have experienced significant growth, and the battery safety of EVs has drawn increased attention. However, the mechanical responses of battery during crashes have rarely been studied. Hence, the objective of this study was to understand EV battery package mechanics during side-pole crashes at different impact locations and speeds beyond regulated side-pole test with one specific speed and one location. An EV finite element (FE) model with a battery package was used. Side-pole impact simulations were conducted at four impact locations, including the baseline impact location according to side-pole impact regulation, plus three positions by moving the rigid pole 400 mm toward the back of the EV and moving the pole 400 and 800 mm toward the front of the EV. In addition, the impact velocities at 32, 50, and 80 km/h were simulated. Based on simulations, the peak relative displacement, the maximum change in gap between batteries, the maximum change in gap between the
Chen, JianBian, KeweiMao, Haojie
Comprehensive requirements generation is a critical stage of the design process. Requirements are used to bound the design space and to guide the selection and evaluation of various solutions. Requirements can be categorized as either functional, defining things that the solution must do (such as produce a certain amount of horsepower), or non-functional, defining desirable qualities of the solution (such as weigh less than a particular value). Functional requirements are relatively easy to define and are often associated with particular components or subsystems within the design. As such, they can be the main focus of academic design instruction and therefore the design projects undertaken by novice designers. However, non-functional requirements (NFRs) capture important characteristics of the design solution and should not be ignored. Because of their nature, they are also difficult to assign to a particular subset of components or subsystem within the system. In this study, a group
Sutton, MeredithAnbuvanan, AadithanCastanier, Matthew P.Turner, CameronKurz, Mary E.
In driving condition, the electric drive system of electric vehicles generates significant heat, which increases temperature of the motor, leading to reduced performance and energy loss. To manage the motor temperature and recover energy, a plate-fin heat exchanger (PFHE) is used to facilitate heat exchange between the electric drive system and the vehicle's thermal management system. In this study, Computational Fluid Dynamics (CFD) method was used to investigate the fin structure on thermal flow performance within the PFHE. The mathematical models of pressure drop and heat transfer of plate-fin heat exchanger are established in this paper, and an empirical formula for the friction factor was derived by using test data. The NTU method was applied to fit the formula of convective heat transfer coefficient, enabling the derivation of an empirical formula for the Colburn factor. A CFD simulation model was developed for a local heat exchange unit, considering the generic boundary
Yin, JintaiYin, ZhihongLu, XuanWang, MengmengLiu, Qian
With increasing attention to complex aerodynamic conditions such as crosswinds, gusts, road turbulence, and vehicle drafting, accurately reconstructing these unsteady and turbulent environments in automotive wind tunnels has become a significant challenge. Addressing this challenge is crucial for broadening experimental conditions and advancing research in unsteady aerodynamics. However, the integration of turbulence generation systems impacts low-frequency fluctuation phenomena, leading to pressure and velocity inaccuracy, and also affects the flow structure in the test section as well, especially in the jet shear layer. In this paper, the impact of an active turbulence generation system on turbulence characteristics and flow structures within jet shear layer in a wind tunnel is numerically investigated. By comparing the flow structure among the empty wind tunnel, and wind tunnel with static and dynamic active turbulence generation system, the mechanisms underlying these
Jia, QingQin, LanweiZhao, CivilWang, YikunXia, ChaoYang, ZhigangWei, Huanxia
To address the issue of signal aliasing when multiple particles pass through a metallic particle sensor, which can lead to misidentification of particle count, we employ numerical simulation methods for an in-depth investigation. We developed a mathematical model of a three-coil inductive metal particle sensor to explore the signal variations induced by the passage of a single particle. We utilized micro-element simulation analysis to dissect the signal generated by a single particle, elucidating the underlying change process. Focusing on dual ferromagnetic particles as the subject of study, we conducted simulations and demodulation of the induced voltage under various combinations of sizes and spacings to investigate the influence patterns of dual adjacent ferromagnetic particles on the sensor's induced signal. Further research into the peak signals of different diameter particles at a constant spacing revealed that, for a given spacing, the ratio of peak signals between particles of
Chen, SenShen, YitaoQiang, GuiyanZheng, ZhengWang, ZheyuHao, YinHu, Ting
The improvement of heat dissipation performance of ventilated brake discs is vital to braking safety. Usually, the technical approaches shall be material optimization or structural improvement. In this paper, a simulation model of the heat transfer of brake discs is established using STAR-CCM+ software. Cast iron, aluminum metal matrix composite (Al-MMC), and carbon-ceramic composite materials (C-SiC) are compared. The results show that: Al-MMC has better thermal conductivity so that a more uniform temperature gradient distribution shall be formed; C-SiC has poorer heat capacity yet, according to previous studies, it has better thermal stability, which is the ability to ensure its friction factor under high-temperature condition; cast iron performs better with convective heat transfer rate, which enhances the heat transfer between the surface and surrounding flow field. Based on the results, this paper proposes four types of material combined brake discs using different friction
Wang, JiaruiJia, QingZhao, WentaoXia, ChaoYang, Zhigang
Model-Based Systems Engineering (MBSE) enables requirements, design, analysis, verification, and validation associated with the development of complex systems. Obtaining data for such systems is dependent on multiple stakeholders and has issues related to communication, data loss, accuracy, and traceability which results in time delays. This paper presents the development of a new process for requirement verification by connecting System Architecture Model (SAM) with multi-fidelity, multi-disciplinary analytical models. Stakeholders can explore design alternatives at a conceptual stage, validate performance, refine system models, and take better informed decisions. The use-case of connecting system requirements to engineering analysis is implemented through ANSYS ModelCenter which integrates MBSE tool CAMEO with simulation tools Motor-CAD and Twin Builder. This automated workflow translates requirements to engineering simulations, captures output and performs validations. System
Upase, BalasahebShroff, Roopesh