Browse Topic: Tests and Testing

Items (24,034)

On-Road Investigation of Energy Saving Opportunity for Autonomous Light-Duty Vehicles through Automated Vehicle-Following in Safe Distance Scenarios

2025-01-8029To be published on 04/01/2025

Reducing aerodynamic drag through vehicle following is one of the energy reduction methods for connected and automated vehicles with advanced perception systems. This paper presents the results of an experimental investigation aimed at assessing energy reduction in manually driven light-duty vehicles through on-road tests of reducing the aerodynamic drag by vehicle following. This study provides insights into the effects of lateral positioning in addition to intervehicle distance and vehicle speed, and the profile of the lead vehicle. A series of tests were employed to analyze the impact of these factors, conducted under realistic driving conditions. The research encompasses various light-duty vehicle models and configurations, with advanced instrumentation and data collection techniques employed to quantify energy-saving potential. The study featured a two set of L4 capable light duty vehicles, including the Stellantis Pacifica PHEV minivan and Stellantis RAM Truck, examined in

Poovalappil, Aman, Robare, Andrew, Schexnaydre, Logan, Santhosh, Pruthwiraj, Bahramgiri, Mojtaba, Bos, Jeremy P., Chen, Bo, Naber, Jeffrey, Robinette, Darrell

Tire wear life prediction using machine learning technique

2025-01-8757To be published on 04/01/2025

As global warming and environmental problems are becoming more serious, tires are required to accomplish balanced performance such as low rolling resistance, wet braking performance, driving stability, and ride comfort, while minimizing wear, noise, and weight. Furthermore, to respond to the rapid changes in the market environment, there is a strong demand for tire performance prediction and testing methods adapted to MBD. In MBD, Magic Formula and Ftire are used in performance design to predict handling and stability and ride comfort. However, predicting tire wear life, which is affected by both vehicle and tire characteristics, is difficult. And practical prediction method for estimating tire wear life has long been awaited. So, we had proposed an experimental-based tire wear life prediction method that using actual measurement tire characteristics and an abrasive wear volume formula. This method achieves accuracy that can be practically used in the early stages of vehicle

ANDO, TAKASHI

Multi-source error analysis for loading disk of suspension kinematics & compliance test bench

2025-01-8291To be published on 04/01/2025

The suspension Kinematics & compliance (K&C) characteristics test bench can simulate the excitation of the road to the wheels under various typical working conditions in a quasi-static manner on the bench, enabling the measurement of the K&C characteristics of the suspension system without knowing the specific suspension structure form, parameters, etc., assisting in the entire design process of the vehicle. In this paper, aiming at various geometric source errors existing in the processing and assembly process of the K&C characteristic test bench, an evaluation method based on the homogeneous transformation matrix is proposed to establish the position error of the center of the end loading disk in the series motion chain. Firstly, the mapping relationship between the position error of the end loading disk in the series mechanism kinematic chain and the assembly error is established by using the homogeneous transformation matrix. Then, the change matrix of the coordinate system from

Sun, Haihua, Duan, Yupeng, Wu, Jinglai, Zhang, Yunqing

Effectiveness of Nail Penetration for Thermal Propagation Test in Battery Packs and Vehicles

2025-01-8128To be published on 04/01/2025

The number of electric vehicles (EVs) has increased significantly in recent years. Consequently, incidents of EV fires have been reported. To protect passengers and evaluate battery robustness, thermal propagation tests are conducted. Typically, these tests initiate a cell in a battery pack using either a heater or a nail. While the heater method is commonly used, the nail method faces restrictions when selecting an initiation cell, especially for battery pack and vehicle testing. For battery pack testing, vertical penetration against the vehicle's travel direction does not have cell selection restrictions. However, for horizontal penetration, the initiation cells are limited to the outermost cells in the battery pack. In vehicle testing, horizontal penetration is unfeasible, whereas vertical penetration from bottom to top is possible. To demonstrate the feasibility of the nail method for battery pack and vehicle testing, especially in vehicles, nail tests were conducted on an electric

Maeda, Kiyotaka, Takahashi, Masashi

A Methodology to Characterize the Influence of Paint Baking and Pre-Straining on the Tensile Properties and Sheared Edge Sensitivity of Third Generation Advanced High Strength Steels

2025-01-8223To be published on 04/01/2025

The existing ASTM A653 standard for characterization of the bake hardening index (BHI) involves application of a pre-strain followed by bake hardening and subsequent testing of an ASTM-E8 tensile coupon that can lead to premature fracture in steels with high strengths and lower elongations. To this end, a new test procedure is proposed with application to 980 and 1180 MPa third generation advanced high strength steels (3G-AHSS). The proposed methodology involves pre-straining over-sized tensile specimens using the so-called KS-1B geometry, which is followed by the extraction of an ASTM E8 sample from the gauge region on which the baking and secondary tensile testing are conducted. Various pre-strain levels from 2% to 10% were considered with all tests performed using the proposed methodology avoiding premature fracture compared to the ASTM A653 method that was evaluated for pre-strain levels of 2% and 8%. Finally, to characterize the influence of paint baking on regions with

Northcote, Rhys Brennan, Berry, Avalon, Narayanan, Advaith, Tolton, Cameron, Butcher, Cliff, McCarty, Eric

Fuzzy Sliding Mode Control of Intelligent Electric Vehicles Based on Phase Plane Stability Domain Boundaries

2025-01-8802To be published on 04/01/2025

In order to effectively improve the chassis handling stability and driving safety of intelligent electric vehicles (IEVs), especially in combing nonlinear observer and chassis control for improving road handling. Simultaneously, uncertainty with system input, are always existing, e.g., variable control boundary, varying road input or control parameters. Due to the higher fatality rate caused by variable factors, how to precisely chose and enforce the reasonable chassis prescribed performance control strategy of IEVs become a hot topic in both academia and industry. To issue the above mentioned, a fuzzy sliding mode control method based on phase plane stability domain is proposed to enhance the vehicle’s chassis performance during complex driving scenarios. Firstly, a two-degree-of-freedom vehicle dynamics model, accounting for tire non-linearity, was established. Secondly, combing with phase plane theory, the stability domain boundary of vehicle yaw rate and side-slip phase plane based

Liao, Yinsheng, Wang, Zhenfeng, Guo, Fenghuan, Deng, Weili, Zhang, Zhijie, Zhao, Binggen, Zhao, Gaoming

Simulating the DrivAer Notchback Car Model using Wall-Function LES

2025-01-8777To be published on 04/01/2025

This paper summarizes work on the application of a new and fully parallelized native GPU-based finite-volume solver on the DrivAER Notchback configuration using a wall-function LES approach. A series of meshes generated using a Rapid-Octree strategy have been investigated, and results for drag, surface pressure coefficient and velocity profile are compared with available experimental data

Menter, Florian, Dalvi, Ashwini, Flad, David, Sharkey, Patrick

Aggressive Autonomous Control on Snow and Ice

2025-01-8040To be published on 04/01/2025

In cold and snowy areas, low-friction and non-uniform road surfaces make vehicle control complex. Manually driving a car becomes a labor-intensive process with higher risks. To explore the upper limits of vehicle motion on snow and ice, we use an existing aggressive autonomous algorithm as a testing tool. We built our 1:5 scaled test platform and proposed an RGBA-based cost map generation method to generate cost maps from either recorded GPS waypoints or manually designed waypoints. From the test results, the AutoRally software can be used on our test platform, which has the same wheelbase but different weights and actuators. Due to the different platforms, the maximum speed that the vehicle can reach is reduced by 1.38% and 2.26% at 6.0 m/s and 8.5 m/s target speeds. When tested on snow and ice surfaces, compared to the max speed on dirt (7.51 m/s), the maximum speed decreased by 48% and 53.9%, respectively. In addition to the significant performance degradation on snow and ice, the

Yang, Yiming, Bos, Jeremy P.

A Sled Test Methodology for 25% Offset Crash Tests

2025-01-8737To be published on 04/01/2025

Sled crash tests are an important tool to develop automotive restraint systems. Compared with full-scale crash tests, the sled test has a shorter development cycle of the restraint system and lower cost. The objective of the present study is to create a cost-effective sled test methodology, calculate the optimal static yaw angle and loading curves, and analyze the motion response and injuries of the dummy in the small-offset crash test. The effectiveness of the proposed methodology was verified under two typical Small Overlap Frontal Crash (SOFC) modes “energy-absorption” and “sideswipe”. The results show that with the calculated yaw angle α, the head HIC was different from the SOFC model, but all remaining indices were within 5% of the injury criteria . All International Organization for Standardization (ISO) values between the combined accelerations of all parts of the dummy and those of the basic model exceeded 0.75, and some values were above 0.8. Therefore, the proposed sled test

Yu, Liu, Chen, Jianzhuo, Wan, Ming Xin, Fan, Tiqiang, Yang, Peilong, Nie, Zhenlong, Ren, Lihai, Cheng, James Chih

Comparative Kinematic Performance Testing to SAE J3230 on a Dynamometer and Test Track

2025-01-8792To be published on 04/01/2025

SAE J3230 provides Kinematic Performance Metrics for Powered Standing Scooters. These performance metrics include many tests which require specific conditions including flat pavement with a near zero slope, drivers of specific height and weights, and data acquisition equipment. In order to determine the efficacy of replicating SAE J3230 tests in a laboratory setting, a device called the Micromobility Device Thermo-Electric Dynamometer was used alongside outdoor tests to provide a comparison of scooter performance in these two testing applications. Based on the testing outcomes, it can be determined whether SAE J3230 and similar standards for other micromobility devices can be replicated in a lab-based setting, saving time, operator hazard, and providing more thorough data outputs

Bartholomew, Meredith, Andreatta, Dale, Zagorski, Scott, Heydinger, Gary

Research on the Motor Mode Control based on the Shut off Test in Dual Motor Hybrid System

2025-01-8576To be published on 04/01/2025

In order to improve the safety and reliability of the inverter used in hybrid vehicles and reduce the risk of inverter failure, based on the functional safety ISO26262 development process and software architecture, a safe shutdown path scheme is designed in this paper. After entering the initialization mode, on the basis of adding the inverter control signal feedback mechanism on the inverter control system, this scheme designs the control methods and specific processes of the shutdown path test and insulation detection. The shutdown path test and insulation detection designed in this scheme are implemented during the control initialization process, including designing the hardware diagnostic safety mechanism and the unique output shutdown path test method. If the shutdown path test or insulation detection fails, the risk of IGBT out of control can be avoided; the detection mechanism of this system can effectively reduce the failure rate and potential failure rate of faults. The CAN

Jing, Junchao, Liu, Yiqiang, Zuo, Botao, Huang, Weishan, Dai, Zhengxing

LLM-Powered Fuzz Testing of Automotive Diagnostic Protocols

2025-01-8091To be published on 04/01/2025

Modern vehicles contain tens of different Electronic Control Units (ECUs) from several vendors. These small computers are connected through several networking busses and protocols, potentially through gateways and converters. Moreover, vehicle-to-vehicle and internet connectivity are now considered to be requirements, adding an addi- tional layer of complexity to an already complex electronic system. Due to this complexity and the safety-critical nature of vehicles, au- tomotive cyber-security a difficult undertaking. One critical aspect of cyber-security is the robust testing of software for potential bugs and vulnerabilities. Fuzz testing is an automated software testing method that injects a large set of inputs to a system. It is an invaluable tech- nique across many industries, and has been increasingly gaining popu- larity since its conception. Its success highly relies on the ”quality” of inputs injected. One shortcoming associated with fuzz testing is the expertise required in

McShane, John, Celik, Levent, Brooks, Richard, Pesé, Mert D., Aideyan, Iwinosa

Development of a Test Course Selection Method for Statistically Correct Wind Modeling on US Public Roads

2025-01-8780To be published on 04/01/2025

Traditional automotive aerodynamic development relies on wind tunnel testing and Computation Fluid Dynamics (CFD), where the former provides reliable values to be used for fuel economy calculations, and the latter enables the investigation of the flow features responsible for improvement/degradation of the averaged large-scale performances in terms of aerodynamic coefficients. The abovementioned procedure overlooks a crucial factor: natural wind. The speed of the wind encountered while driving alters the vehicle’s effective yaw angle. Such condition implies that the minimization of the drag coefficient at zero-yaw, commonly performed through wind tunnel testing and CFD simulations, may not yield real-world optimal shapes. While it is possible to employ a wind signal as an input in a wind tunnel, the signal itself must be available beforehand, and such key element is the focus of the present research effort. In this paper, we explain a methodology behind the selection of a statistically

Nucera, Fortunato, Onishi, Yasuyuki, Metka, Matt

Investigation of Skin Friction Topology on the AeroSUV Using GLOF Meter

2025-01-8782To be published on 04/01/2025

In this study, the aerodynamics and skin flow field of a 1/5 scale SUV vehicle model called “AeroSUV” were experimentally investigated. The aerodynamics and skin flow field investigations were carried out in the wind tunnel at Hiroshima University with a Reynolds number ReL = 1.2×10^6, baseline yaw angle β = 0° and crosswind conditions β = 5°, 10° and 15° for two rear ends, Estateback and Fastback. The results provide aerodynamic information and detailed skin flow field information for a standard middle-class SUV vehicle with different rear ends, which is important for automotive design. By applying GLOF measurements to automotive aerodynamics, the skin friction topology was revealed in detail as skin flow field information that is useful for understanding the physics of the flow. The skin friction topology clearly shows the separation lines, reattachment lines, and focus points associated with the separation flow, longitudinal vortices and recirculation vortices of this vehicle model

Hijikuro, Masato, Shimizu, Keigo, Nakashima, Takuji, Hiraoka, Takenori

Characterisation and variabilities of aerosols produced by tyres rotating on wet surfaces

2025-01-8763To be published on 04/01/2025

Understanding the formation and behaviour of aerosols generated by vehicles traveling on wet surfaces is crucial due to their impact on vehicle soiling, visibility, and autonomous driving. These aerosols can reduce visibility for other drivers, contribute to traffic accidents, and reduce the operational capabilities of sensors for driving assistance systems and future autonomous vehicles. Despite the importance of understanding the physical properties of these aerosols is crucial for testing and validating sensors for environmental perception and recognition, field data on this topic is scarce. The formation and behaviour of these aerosols are complex. A fraction of the trailing droplets and ligaments originates directly from the tyres, while the remainder is generated upon the impact of the particles ejected from the tyres with the vehicle’s surfaces, resulting in either coalescence or further disintegration. Aerodynamic forces also significantly influence the formation of these

Otxoterena, Paul, Kallhammer, Jan-Erik, Eriksson, Peter, Ronelov, Erik

CAATS - Automotive Wind Tunnel Calibrations

2025-01-8762To be published on 04/01/2025

Wind tunnel calibration is necessary for repeatable and reproducible data for all industries interested in their output. Quantities such as wind speed, pressure gradients, static operating conditions, ground effects, force and moment measurements, as well as flow uniformity and angularity are all integral in an automotive wind tunnel’s data quality and can be controlled through appropriate calibration, maintenance, and statistical process control programs. The purpose of this technical paper is to (1) provide a basis of commonality for automotive wind tunnel calibration, (2) help customers and operators to determine the calibration standards best suited for their unique automotive wind tunnel and, (3) complement the American Institute of Aeronautics and Astronautics recommended practice R-093-2003(2018) Calibration of Subsonic and Transonic Wind Tunnels as specifically applied to the automotive industry. This document compiles information from various automotive wind tunnel customers

Bringhurst, Katlynn, Best, Scott, Nasr Esfahani, Vahid, Senft, Victor, Stevenson, Stuart, Wittmeier, Felix

Research on road-sense simulation algorithm and analysis of its effect on different steering wheels

2025-01-8753To be published on 04/01/2025

With the continuous development of automotive intelligence, cars increasingly want chassis to be more intelligent, electronically controlled, integrated and lightweight. Therefore, the steer-by-wire system, controlled by the line, with high precision and fast response, can provide better flexibility, stability and comfort for the car and can well meet the above requirements, has been widely concerned. As the steer-by-wire system eliminates the mechanical structure, the road sense cannot be directly transmitted to the steering wheel. The road sense obtained according to the vehicle state or combined with the driving environment planning needs to be applied to the steering wheel through the road sense motor to complete the simulation of the road sense so that the driver can feel the feedback similar to driving the traditional steering vehicle. In this way, the driving experience of the driver can be increased. It can also enhance driving safety, so it is very important to study the road

Li, Shang, Zheng, Hongyu, Kaku, Chuyo

On the critical importance of physical modelling for the analysis of coastdown data

2025-01-8774To be published on 04/01/2025

Novel experimental and analytical methods were developed, with the objective of improving the reliability and repeatability of aerodynamic and road-load results derived from coastdown tests. The new methods were applied in the context of a coastdown test campaign conducted using a SUV and a tractor-trailer. Both vehicles had been tested in the NRC 9m Wind Tunnel, providing aerodynamic comparison-points. The rationale behind the novel techniques was to minimize the number of unknowns in the equation of motion by measuring directly the following parameters: axle mechanical resistance, rolling resistance at low speed and wheel-axle moments of inertia. This was achieved, respectively, by means of an axle-deceleration apparatus, a low-speed hauling facility and a wheel-oscillator developed for this study. In addition, the speed-dependence of tire rolling resistance was measured at a private laboratory, via rotating-drum tests, and modeled using a previously-validated exponential formulation

de Souza, Fenella, Tanguay, Bernard

An Investigation of the Inter-Vehicle Distances and Lateral offsets on Aerodynamic Forces and Wake Structures of Vehicles Platooning

2025-01-8769To be published on 04/01/2025

In traffic scenarios, the spacing between vehicles plays a crucial role, as the actions of one vehicle can significantly impact others, particularly with regards to energy conservation. Accordingly, modern vehicles are equipped with inter-vehicle communication systems to maintain specific distances between vehicles. The aerodynamic forces experienced by both leading vehicles (leaders) and following vehicles (followers) are connected to the flow patterns in the wake region of the leaders. Therefore, improving our understanding of the turbulent characteristics associated with vehicles platooning is important. This paper investigates the effects of inter-vehicle distances on the flow structure of two vehicles: a small SUV as the leader and a larger light commercial van as the follower, using a Delayed Detached Eddy Simulation (DDES) CFD technique. The study focuses on three specific inter-vehicle distances: S = 0.28 L, 0.4L, and 0.5L, where S represents the spacing between the two

Mosavati, Maziar, Guzman, Arturo, Lounsberry, Todd, Fadler, Gregory

Integrated Nonlinear Observer and Prescribed Performance Control for a Four In-wheel Motor-Driven Electric Vehicles Based on Phase Plane and Road Classification

2025-01-8298To be published on 04/01/2025

To effectively improve the performance of chassis control of a four in-wheel motor (IWM)-driven electric vehicles (EVs), especially in combing nonlinear observer and chassis control for improving road handling and ride comfort, is a challenging task for the IWM-driven EVs. Simultaneously, inaccurate state-based control and uncertainty with system input, are always existing, e.g., variable control boundary, varying road input or control parameters. Due to the higher fatality rate caused by variable factors, how to precisely chose and enforce the reasonable chassis prescribed performance control strategy of IWM-driven EVs become a hot topic in both academia and industry. To issue the above mentioned, the paper proposes a novel observer-based prescribed performance control to improve IWM-driven EVs chassis performance under the double lane change steering and various road input. Firstly, a nonlinear nine degree-of-freedom of full-car model is developed to describe vehicle chassis dynamics

Wang, Zhenfeng, Zhao, Binggen

Impact of Thermal and Electrical Dissimilarities on Battery Module Aging

2025-01-8173To be published on 04/01/2025

Battery cell aging and loss of capacity are some of the many challenges facing the widespread implementation of electrification in mobility. One of the factors contributing to cell aging is the dissimilarities of individual cells connected in a module. This paper reports the results of several aging experiments using a mini-module consisting of seven 18.2 Ah 21700 Lithium-ion battery cells connected in parallel. The aging cycle comprised a constant current-constant voltage charge cycle at a 0.7C C-rate, followed by a 0.2C constant current discharge, spanning the useful voltage range from minimum to maximum according to the cell manufacturer. Charge and discharge events were separated by one-hour rest periods and were repeated for four weeks. Weekly reference performance tests were executed to measure static and pulse power capacity as well as discharge impedance. All diagnostics were normalized with respect to their starting numbers to achieve a percentage change over time. Both

Swarts, Andre, Salvi, Swapnil S., Juarez Robles, Daniel

An Approach Towards the Input Load Calculation for Determining Vehicle Body Durability Performance in Proving Ground

2025-01-8286To be published on 04/01/2025

In the competitive automotive market, the vehicle must be designed and validated quickly without compromising the build quality. Vehicle durability is one of the key aspects in which vehicle structure quality can be analysed. The vehicle's durability is tested either by the accelerated testing equipment e.g. multi-axial simulators in the test labs or "Proving ground" testing which depicts the same quantum of damage which occurs in actual road running conditions. In both these cases, the actual prototype vehicle must be built and evaluated which increases the cost and actual product development time. Proving Ground simulation is an alternative way to the actual endurance test running for durability evaluation. The two major steps for Proving Ground simulation are to build and extract the loads at the suspension-body attachment points and to calculate the fatigue life of the body using these loads. In this paper, two approaches of load extraction at the attachment points have been

Sri Harsha, IVN, Gupta, Praneet, Matharu, Ranjit Singh

Study on an Urban Ramp Driving Cycle Using Self-Organizing Map Neural Network

2025-01-8259To be published on 04/01/2025

To tackle the issue of lacking slope information in urban driving cycles used for vehicle performance evaluation, a construction method for urban ramp driving cycle (URDC) is formulated based on self-organizing map (SOM) neural network. The fundamental data regarding vehicles driving on typical roads with urban ramp characteristics and road slopes were collected using the method of average traffic flow, which were then pre-processed and divided into short trips; and twenty parameters that can represent the operation characteristics of vehicle driving on urban ramp were selected as the feature parameters of short trip. Dimension of the selected feature parameters was then reduced by means of principal component analysis. And a SOM neural network was applied in cluster analysis to classify the short trips. An URDC with speed and slope information were constructed by combination of short trips with highly relevant coefficients according to the principle of smooth connection of slope. The

Yin, Xiaofeng, Wu, Zhimin

A Novel Hybrid Approach for Segmenting Driver Based on their Driving Style

2025-01-8205To be published on 04/01/2025

Drivers present a diverse landscape with their distinct personalities, preferences, and driving habits influenced by many factors. While drivers exhibit a wide range of behaviors, identifiable patterns in driving styles enable the classification of drivers into discrete segments. Discrete segmentation provides a practical and effective way to categorize and address the differences in driving style. The segmentation approach offers many benefits, including simplification, measurement, proven methodology, customization, and safety. Numerous studies have investigated driving style classification using real-world vehicle data. These studies employed various methods to identify and categorize distinct driving patterns, including naturalist differences in driving and field operational tests. This paper presents a novel hybrid approach for segmenting driver behavior based on their driving patterns. We leverage vehicle acceleration data to create granular driver segments by combining event

Chavan, Shakti Pradeep, Chinnam, Ratna Babu

A Study of Tire Handling and Ride Performance Map according to Tire Tread Wear State

2025-01-8760To be published on 04/01/2025

The electric vehicle market is expected to grow further within the automotive industry, driven by the increasing computing power of vehicle ECUs and the advancement of SDV(Software Defined Vehicle) systems. The results of these advanced and expanded vehicle technologies will offer customers higher quality and increased productivity in the market. A practical application of this technology is tire wear prediction algorithms. Tire wear prediction algorithms can inform customers of the optimal time to change tires while also allowing chassis control systems and other ADAS systems to adjust to varying tire performance as wear conditions change. This trend is growing, prompting several automakers to invest in developing these advanced technologies to enhance their product quality and safety. Therefore, it is essential to understand how vehicle handling and ride performances can change in response to varying tire wear conditions to evaluate the effectiveness of tire wear algorithms. This

Kim, Changsu

Spectral Estimation to Quantify Road/Track Surface Degradation

2025-01-8252To be published on 04/01/2025

Track testing methods are utilized in the automotive industry for emissions and fuel economy certification. These track tests are performed on smooth road surfaces which deteriorate over time due to wear and weather effects, hence warranting regular track repaves. The study focuses on the impact of repaving on track quality and surface degradation due to weather effects. 1D surface profiles and 2D surface images at different spatial frequencies were measured at different times over a span of two years using various devices to study the repave and degradation effects. Data from coastdown tests was also collected over a span of two years and is used to demonstrate the impact of track degradation and repaving on road load characterization parameters that are used for vehicle certification tests. Kernel density estimation and non-parametric spectral estimation methods are used to visualize the characteristic features of the track at different times. In the pre-processing stage, outliers

Singh, Yuvraj, Jayakumar, Adithya, Rizzoni, Giorgio

A zero-emission braking system: experimental setup, system characterization and model validation

2025-01-8250To be published on 04/01/2025

Following the current need of the automotive sector on reducing secondary emissions coming from non-exhaust sources, this paper presents an innovative zero-emissions magneto-rheological braking system, specifically designed to meet future brake emission targets while maintaining state-of-the-art brake performance. In particular the article focusses on the experimental setup definition to evaluate the full-sized prototype under real load conditions and presents the preliminary results obtained from the experimental campaign. The zero-emission braking prototype has been developed for reaching performance compatible with the automotive application, specifically a segment-A vehicle, being able to generate enough braking torque as to perform an emergency brake maneuver without any other traditional braking system. A central aspect to confirm system’s performance is the development of a test bench engineered for assessing the magneto-rheological braking technology. Detailed insights into the

De Carlo, Matteo, Tempone, Giuseppe Pio, Imberti, Giovanni, de Carvalho Pinheiro, Henrique, Carello, Massimiliana

Validation of Elastomeric SLA Control Arm Bushing Fatigue Life Under Multi-Channel Road Load Input

2025-01-8235To be published on 04/01/2025

The rapid virtualization of engineering workflows for elastomer parts calls for the pairing of robust simulation capabilities with correspondingly thorough validation. Continuing prior work, which established a simulation workflow for simulating fatigue performance of elastomeric bushings operating under a full schedule of 6 channel (3 forces + 3 moments) road load histories, the present report presents the results of an experimental program comparing predicted and measured fatigue performances for an SLA control arm bushing. The experimental fatigue testing program was conducted on a servo-hydraulic 3 axis test rig. The rig was designed to provide radial (cross-car), axial (for-aft), and torsional inputs into the bushing. The test schedule was comprised of 11 virtual test track events. The individual events were run using remote parameter control playback of virtual road load data acquisition signals. Four bushings were operated under the subject loading schedule. Bushings were tested

Mars, WILL, Barbash, Kevin, Wieczorek, Matthew, Pham, Liem, Braddock, Scott, Steiner, Ethan, Strumpfer, Scott

Dynamic Driving Task Assessment Scores for Scenarios Navigated by an OEM ADS-Equipped Vehicle

2025-01-8672To be published on 04/01/2025

One of the major issues facing the automated driving system (ADS)-equipped vehicle (AV) industry is how to evaluate the performance of an AV as it navigates a given scenario. The development and validation of a sound, consistent, and transparent dynamic driving task (DDT) assessment (DA) methodology is a key component of the safety case framework (SCF) of the Automated Vehicle – Test and Evaluation Process (AV-TEP) Mission, a collaboration between Science Foundation Arizona and Arizona State University. The DA methodology was presented in earlier work, and includes the DA metrics from the recently published SAE J3237 Recommended Practice. This work implements the methodology with an AV developed by OEM May Mobility in five diverse scenarios: (1) VRU crossing in front of the AV’s path, (2) an oncoming vehicle entering the AV’s lane, (3) a vehicle executing a three-point turn encroaches into the AV’s path, (4) the AV departing its lane in a parking lot, and (5) the AV exhibiting

Wishart, Jeffrey, Rahimi, Shujauddin, Swaminathan, Sunder, Zhao, Junfeng, Como, Steven Gerard

Mitigating Paint Blistering Defects in Aluminum Casted Parts: A QC Story Approach Utilizing Computed Tomography

2025-01-8229To be published on 04/01/2025

Blistering in aesthetic parts poses a significant challenge, affecting overall appearance and eroding brand image from the customer's perspective and blister defects disrupt painting line efficiency, resulting in increased rework and rejection rates. This paper investigates the causes and effects of blistering, particularly in the context of internal soundness of Aluminium castings, emphasizing the crucial role of Computed Tomography in defect analysis. Computed Tomography is an advanced Non-Destructive Testing technique used to examine the internal soundness of a material. This study follows a structured 7-step QC story approach, from problem identification to standardization, to accurately identify the root Cause and implement corrective actions to eliminate blister defect. The findings reveal a strong link between internal soundness and surface quality. Based on the root cause, changes in the casting process and die design were made to improve internal soundness, leading to reduced

D, Balachandar, Nataraj, Naveenkumar

Time Step Analysis of Sliding Mesh Rotation Modeling

2025-01-8626To be published on 04/01/2025

This paper analyzes the accuracy and computational cost of increasing the time-step size on a production vehicle while using Sliding Mesh (SM) for the rotation modeling of the wheels with two turbulence models (Unsteady Reynolds-Averaged Navier-Stokes (URANS) and Delayed Detached-Eddy Simulations (DDES)). The current recommendations of using a SM model are too computationally expensive to be used in a consistent manner, especially compared to a Moving Reference Frame (MRF) model for the wheels. While changing the time-step size from 1x - 50x, 1x being the current recommendations of 1 degree of rotation on the wheels per time-step, a CFD analysis of a mass-production vehicle model was compared to wind tunnel data using time-averaged flow. The DDES simulations were more robust at larger time steps compared to the URANS simulations. The drag coefficients and flow field was more consistent to the wind tunnel data for SM compared to using a MRF rotation model for the wheels even at the

Struk, Michael, AULTMAN, MATTHEW, Disotell, Kevin, Duan, Lian, Bianco, Antonello, Metka, Matt, Khasdeo, Nitin, Ramsay, Thomas

Driving in the Rain: Evaluating How Surface Material Properties Affect Lidar Perception in Autonomous Driving

2025-01-8016To be published on 04/01/2025

Light Detection and Ranging (LiDAR) is a promising type of sensor for autonomous driving that utilizes laser technologies to provide perceptions and accurate distance measurements to obstacles in the vehicle path. In recent years, there has also been a rise in the implementation of LiDARs in modern and autonomous vehicles to aid the self-driving features. However, navigating in adverse weather remains to be one of the biggest challenges in achieving Level 5 full autonomy due to sensor soiling, which subsequently leads to performance degradation that poses safety hazards. When driving in rain, raindrops impact the LiDAR sensor assembly and cause attenuation of signals when the light beams undergo reflections and refractions. Consequently, signal detectability, accuracy, and intensity are significantly affected. To date, limited studies were able to perform objective evaluations of LiDAR performance, most of which faced limitations that hindered realistic, controllable, and repeatable

Pao, Wing Yi, Li, Long, Agelin-chaab, Martin, Roy, Langis, Knutzen, Julian, Baltazar, Alex, Muenker, Klaus, Chakraborty, Anirban, Komar, John

Compensation Algorithm Development in Platform for Pedestrian ADAS Testing

2025-01-8066To be published on 04/01/2025

Test procedures such as EuroNCAP, NHTSA’s FMVSS 127, and UNECE 152 all require specific pedestrian to vehicle overlaps. These overlap variations allow the vehicle differing amounts of time to respond to the pedestrian’s presence. In this work, a compensation algorithm was developed to be used with the STRIDE robot for Pedestrian Automatic Emergency Braking tests. The compensation algorithm uses information about the vehicle’s speed and position to determine whether the robot needs to move faster or slower in order to properly overlap the vehicle. Tests of the algorithm include two different methodologies for testing functionality and the use of a robotic test driver to vary the vehicle speed in a consistent manner

Bartholomew, Meredith, Nguyen, An, Helber, Nicholas, Heydinger, Gary

Research on the Thermal Performance of Thick Film Heater for Electric Vehicle Battery

2025-01-8154To be published on 04/01/2025

The life of power battery and its discharge efficiency in electric cars will be significantly reduced in a low temperature environment. Therefore, in order to ensure its working mileage and safety, heating the power battery is required. Heat pump air conditioners and PTC-based onboard heaters are usually way to heat the power battery under lower temperature so far. In low temperature environment, due to the lower heating efficiency of the heat pump air conditioner, onboard heaters are widely used in electric cars. A specific thick film heater(TFH) for electric vehicles is investigaed in this study, and its three dimensional heat tansfer analysis model is established. The heat transfer and fluid performace of the TFH is analied using a computational fluid dynamics software. The performance of TFH is measured on a test bench, and the measured data is used to validate the developed model. Using the established model, the heating efficiency of TFH is studied for different inlet

Guan, Wenzhe, Guo, Yiming, Wu, Xiaoyong, Wang, Dongdong, Shangguan, Wen-Bin

The New China Automotive Engineering Research Institute Co., Ltd Full-Scale Aero-acoustic Wind Tunnel

2025-01-8779To be published on 04/01/2025

The China Automotive Engineering Research Institute Co., Ltd (CAERI) has completed a new vehicle aero-acoustic wind tunnel (AAWT), which is located in Chongqing, China, and has been in operation for 5 years. To help address Chinese vehicle market’s need to improve fuel economy, reduce exhaust emissions, and decrease product development period, the wind tunnel was designed and implemented to achieve high degree of automation for vehicle test and high accuracy aerodynamic and acoustic test for product development. The CAERI wind tunnel was in operation in August 2019, which has a top speed of 250 kph, a 5-belt rolling road system with a long center belt for proper wake simulation, a test section with very low static pressure gradient, background noise and an overhead traverse both for wind tunnel calibration and customized measurement activities. This paper describes the main facilities of AAWT including some auxiliary equipment. The aerodynamic and acoustic performances of the CAERI

Xu, Lei, Zhu, Xijia, Wang, Qingyang, Bu, Han, Peng, Chao, Shi, Feng, Yang, Chao, Huang, Tao, Zeng, Yi, Zeng, Xiangyi, Wallmann, Steffen, Münstermann, Henning, Wittmeier, Felix, Mercker, Edzard, Blumrich, Reinhard

Supervisory Control System Development for a Toyota Mirai FCEV

2025-01-8586To be published on 04/01/2025

The performance of a second-generation Toyota Mirai fuel cell was characterized as part of the SwRI internal research program. This data was used to develop a supervisory controller scheme designed to balance the plant for the fuel cell system during steady-state and transient vehicle conditions. This was accomplished using a Supervisory Integrated Controller (SIC) implemented on a Real-time Power Electron- ics Control System (RPECS) with a Simulink-based control algorithm. The actuators of interest are the three hydrogen injectors at anode inlet, air compressor and three air side valves on at the cathode inlet. The FC power measurement and pressure sensor readings at the anode and cathode were utilized as real-time feedback for the controller operation. The aim of the controller was to achieve and maintain the power target set by the hybrid powertrain ECU present on the vehicle, which is responsible for balancing power on the fuel cell and battery over the high-voltage bus. These

Chundru, Venkata Rajesh, Kubesh, Matthew, Legala, Adithya

DCFC EVSE Security

2025-01-8118To be published on 04/01/2025

The rapid spread of electric vehicles (EVs) and EV charging stations requires an urgent focus on the security of the entire charging infrastructure. As EV charging stations are a major interface in the charging infrastructure, ensuring cybersecurity of the personal and private data transmitted to and from chargers is a key component to the overall security. To evaluate the security of a part of the EV charging ecosystem, researchers from Southwest Research Institute® (SwRI®) assessed the vulnerability of a DC Fast Charging (DCFC) EV Supply Equipment (EVSE)’s communication protocol and system. The researchers established an undetected Adversary in the Middle (AitM) between the EV and EVSE to examine the communication used between the two. They identified vulnerabilities that exposed critical data—such as the MAC address of both the EV and EVSE—either sent in plaintext or encrypted with a known algorithm. These values allowed for reprogramming of the non-volatile memory of Power-Line

Kozan, Katherine

Fluid topology optimization for heat dissipation of Ventilated brake discs

2025-01-8183To be published on 04/01/2025

Passenger car ventilated brake disc is a rotating structure, which has a similar motion to impeller machinery and similar performance indexes to devices such as radiators. The optimization of the heat dissipation performance of a ventilated brake disc is a complex problem that includes fluids, solids, rotational motion, heat and friction. To address this problem, this paper built a brake disc heat dissipation simulation model based on the wind tunnel test of a MPV model with constant speed heat dissipation, compared the advantages and disadvantages of the two preconfigured discs; analyzed the sensitivity of each design parameter of the brake disc blade, and introduced the method of topology optimization in the optimization of the brake disc heat dissipation performance. The topology optimization method was demonstrated to be feasible to be applied to the complex system of brake disc thermal simulation, and through this, a brake disc blade with a special shape was obtained, and the

Zhao, Civil, Jia, Qing, Qin, Lanwei, Xia, Chao, Yang, Zhigang

Application of 1.7GPa Martensitic Steel in Dash Lower Cross Member to Enhance Automotive Frontal Impact Safety

2025-01-8218To be published on 04/01/2025

The rapid growth of electric vehicles (EVs) has led to a significant increase in vehicle mass due to the integration of large and heavy battery systems. This increase in mass has raised concerns about collision energy and the associated risks, particularly in high-speed impacts. As a consequence, crashworthiness evaluations, especially front-impact regulations, have become increasingly stringent. Crash speed between the vehicle and the Mobile Progressive Deformable Barrier (MPDB) is increasing, reflecting the growing emphasis on safety in the automotive industry. Moreover, a new frontal pole crash scenario is under consideration for future regulatory standards, highlighting the continuous evolution of crash testing protocols. To ensure occupant protection and battery safety, manufacturers have traditionally used Hot Blow Forming technology for producing closed-loop dash lower cross member components. However, this process is both costly and energy-intensive, necessitating more

Lee, Jongmin, Kim, Donghyun, JANG, MINHO, Kim, Geunho, Seongho, Yoo, Kim, Kyu-Rae

Advanced Methodology for Accelerated Durability Block Cycle Testing of Automotive Rubber Suspension Bushings and Powertrain Mounts

2025-01-8236To be published on 04/01/2025

In the field of automotive engineering, the performance and longevity of suspension bushings and powertrain mounts are critical. These components must endure fatigue loads characterized by their variable amplitude, multi-axial nature, and out-of-phase oscillations. The challenge lies in comprehensively characterizing these service loads during the early stages of vehicle production to foresee potential issues that may arise during later stages. Additional complexity in this analysis is introduced by the nonlinear hyperelastic deformation exhibited by natural rubber, a common material used in these components. To address these challenges, original equipment manufacturers (OEMs) and suppliers employ Computer-Aided Engineering (CAE) techniques for fatigue life predictions. These predictions are complemented by physical testing involving what are known as block cycles. However, the results obtained from these approaches often fail to fully represent the real loading conditions that a

ZARRIN-GHALAMI, Touhid, Datta, Sandip

Automotive fatigue load spectra: modelization, identification and applications

2025-01-8240To be published on 04/01/2025

Fatigue design is invariably of prior concern for the automotive industry, no matter of the evolution of the mobility market: at first because carmakers have to stay compliant with general structural integrity requirements for reliability, notably applicable to the chassis system, then due to the endless competition for lightweighting in order to mitigate product costs and/or enhance vehicle efficiency. In the past, this key performance was often tackled by basic reference load cases, making use of the simplest signal content, e.g. sinus functions, to practice constant amplitude loads on test rigs and for computations, respectively. Nowadays, full time series coming from proving ground measurements, or any corresponding virtual road load data computations, may be applied to feed complex vehicle computations for virtual assessment and complex test facilities for final approval, under variable amplitude loads. In between, the concept of load spectra (i.e. distribution of amplitudes with

Facchinetti, Matteo Luca, Tjhung, Tana, Jaffre lng, Sébastien, Datta, Sandip, Hayat lng, Romain, Guo, Mingchao

Adapting the Technology Readiness Level (TRL) Framework to AV Development

2025-01-8671To be published on 04/01/2025

The technological advancements in the automotive industry have seen a significant leap with the introduction of ADS-Equipped Vehicles (AVs), with potential for enhanced safety, efficiency, and convenience. 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 state 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. Advancing from one TRL to the next is argued through the satisfaction of requirements

Swaminathan, Sunder, Wishart, Jeffrey, Zhao, Junfeng, Russo, Brendan, Rahimi, Shujauddin

Correlation of Vehicle drop test in front & rear wheel landing condition using multibody dynamics simulations

2025-01-8638To be published on 04/01/2025

Two wheelers motorcycles are used for many purposes e.g. commuting from place to another, long highway rides, racing and off-roading. Motorcycles which are used in off-road conditions require large suspension strokes to absorb large oscillations due to road conditions. These motorcycles undergo jumps of different heights and different vehicle orientations. In some of the dynamic situations front wheel may land first than the rear and in some of the situations rear may land first as compared to front. To make sure that the vehicle is durable enough to withstand loads in such operating conditions, vehicle drop test was developed at component test lab where vehicle is dropped from predefined heights in both front & rear wheel landing conditions. Same load case is simulated in multibody dynamics to capture loads at important connections of the frame. This paper presents the correlation exercise carried out to validate MBD model and simulation process with test data captured during lab test

Jain, Arvind Kumar, Nirala, Deepak

Investigation of the Blockage Phenomenon in Closed Wall Wind Tunnels During the Testing of Bluff Automotive Bodies with Large Wakes in Yawed Configurations

2025-01-8786To be published on 04/01/2025

Abstract The difficulties of testing a bluff automotive body of sufficient scale to match the on-road vehicle Reynolds number in a closed wall wind tunnel has led to many approaches being taken to adjust the resulting data for the inherent interference effects. But it has been very difficult to experimentally analyze the effects that are occurring on and around the vehicle when these blockage interferences are taking place. The present study is an extension of earlier works by the author and similarly to those studies uses the computational fluid dynamics analysis of four bodies that generate large wakes to examine the interference phenomena in solid wall wind tunnels and the effects that they have on the pressures, forces and force increments experienced by the vehicle model when it is in yawed conditions up to 20 degrees. This is accomplished by executing a series of CFD configurations with varying sized cross sections from 0.4% to 14% blockage enabling an approximation of free air

Gleason, Mark, Riegel, Eugen

Impact of Active Turbulence Generation System in 3/4 Open-Jet Wind Tunnel: Flow Structures, Shear Layer, and Low-Frequency Fluctuations

2025-01-8783To be published on 04/01/2025

With increasing attention to complex aerodynamic conditions such as crosswinds, gusts, road turbulence, and vehicle queuing, 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 blank wind tunnel, and wind tunnel with static and dynamic active turbulence generation system, the mechanisms underlying these configurations

Jia, Qing, Qin, Lanwei, Zhao, Civil, Wang, Yikun, Xia, Chao, Yang, Zhigang, Wei, Huanxia

The aerodynamics development of the New Range Rover

2025-01-8781To be published on 04/01/2025

The New Range Rover is the fifth generation of this luxury SUV. With a drag coefficient of 0.30 at launch, it was the most aerodynamically efficient luxury SUV in the world. This aerodynamic efficiency was achieved by applying the latest science. Rear wake control was realised with a large roof spoiler, rear pillar and bodyside shaping, along with an underfloor designed to reduce losses over a wide range of vehicle configurations. This enabled manipulation of the wake structure to reduce drag spread, optimising emissions measured under the WLTP regulations. Along with its low drag coefficient, in an industry first, it was developed explicitly to achieve reduced rear surface contamination with reductions achieved of 70% on the rear screen and 60% over the tailgate when compared against the out-going product. This supports both perceptions of luxury along with sensor system performance, demonstrating that vehicles can be developed concurrently for low drag and reduced rear soiling. This

Chaligné, Sébastien, Gaylard, Adrian Philip, Simmonds, Nicholas, Turner, Ross

Investigation of flow structures in different body types contributing to drag change due to crosswind

2025-01-8767To be published on 04/01/2025

To reduce aerodynamic drag during real world driving, it is important to consider the effect of crosswinds. In this study, we investigated the differences in flow structures between an SUV and a notchback to understand the mechanism behind the difference in yaw angle dependence of Cd value when a quasi-steady yaw angle is applied. In this study, simulations and wind tunnel tests were performed for the SUV and the notchback with yaw angles of 0°, 2°, and 5°. The indicator of flow structure analysis were crossflow and total pressure, and the results of wind tunnel tests and simulations were visualized, focusing on rear wake. In addition, iso-surfaces and path lines around the vehicle were visualized in detail, using the results of simulations. These results revealed the differences in flow structures depending on the body type. In the case of the notchback, the main vortex at yaw angle zero is behind the C-pillar. When a yaw angle is applied, this becomes stronger on both the leeward and

Nakata, Akihiro, Okamoto, Satoshi, NISHIDA, Shuhei, Morikawa, Yosuke, Nakashima, Takuji

Research on Segmented Latency Testing Method for In-Vehicle Real-Time Systems Based on DDS Middleware

2025-01-8083To be published on 04/01/2025

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, Yanhua, Luo, Feng, Ren, Yi, Hou, Yongping

High Performance Computer Based Software Defined Vehicle Hardware in the loop testing

2025-01-8137To be published on 04/01/2025

Recent years have seen a strong move towards Software Defined Vehicle concept as it is seen as an enabler for advancing the mobility by integrating complex technologies like Artificial Intelligence (AI) and Connected Autonomous Driving (CAD) into the vehicle. However, this comes with fundamental changes to the vehicle’s Electrical/Electronic (EE) architecture which require novel testing approaches. This paper presents FEV’s SDV Hardware-In-The-Loop (HIL) test setup which focuses on testing the developed HPC-based software. The functionality of the SDV HIL test setup is demonstrated by testing the software of multiple technologies within the HPC environment like ADAS and teleoperation virtual control units with OTA capability. Test results show the effectiveness of utilizing FEV’s HIL setup in developing and validating the software of SDV platforms

Alzu'bi, Hamzeh

The Guangzhou Automotive Group Co. Aerodynamic, Acoustic, and Thermal Wind Tunnel

2025-01-8788To be published on 04/01/2025

The Guangzhou Automotive Group Co., Ltd (GAC Group) wind tunnel, located in Guangzhou, China, is a state-of-the-art facility that uniquely integrates world-class aerodynamic flow quality, acoustic capability, and thermal conditions into a single system for the development of passenger vehicles. This closed return, ¾ open jet wind tunnel features a nozzle with a cross-section of 20 m² and a 2.5 MW fan, capable of delivering a maximum wind speed of 200 km/h. The wind tunnel is equipped with a ±90° turntable, a boundary layer control system, and a 5-belt moving ground plane system for aerodynamic tests. Comprehensive acoustic treatments in the test section and throughout the wind tunnel circuit establish a hemi-anechoic test environment with minimal background noise levels for acoustic tests. For thermal tests, the wind tunnel includes a 4-wheel chassis dynamometer system downstream of the turntable, with temperature control ranging from 20°C to 60°C and humidity control between 15% and

Bender, Trevor, Nasr Esfahani, Vahid, Liu, Zheng, Yang, Hui, Li, Shuya, song, Xin, liu, Man, Ma, Zhijian

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