bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation on Combustion Stability, Unregulated and Particle Emissions in RCCI Engine
Authors: Yadav Ratnesh Kumar , Saxena Mohit Raj , Maurya Rakesh Kumar
Published: April 2024

This study experimentally investigates the combustion stability in RCCI engines along with the gaseous (regulated and unregulated) and particle emissions. Multifractal analysis is used to characterize the cyclic combustion variations in the combustion parameters (such as IMEP, CA50, and THR). This analysis aims to investigate the multifractal characteristics of the RCCI combustion mode near the misfiring limit. The investigation is carried out on a modified single-cylinder diesel engine to operate in RCCI combustion mode.The RCCI combustion mode is tested for different diesel injection timing (SOI) at fixed engine speed (1500rpm) and load (1.5 bar BMEP). The particle number characteristics and gaseous emissions are measured using a differential mobility spectrometer (DMS500) and Fourier Transform Infrared Spectroscopy (FTIR) along with Flame Ionizing Detector (FID), respectively. The results indicate that the NOx emissions decrease with advanced SOI while the Total Hydro-Carbon (THC) emission increases. The result shows that advanced SOI decreases the formation of propylene (C3H6), ethylene (C2H4), 1-3 butadiene (C4H6), and methane (CH4). However, formaldehyde (HCHO) emission increased with advanced SOI. The emission of the total particle number (PN) and nucleation mode particles (NMPs) decreased with advanced diesel SOI. Multi-Fractal Detrended Fluctuation Analysis (MFDFA) demonstrated a positive correlation between diesel SOI and the level of multifractality. It is found that the time series of combustion parameters exhibits large fluctuations at smaller time scales, while small fluctuations are detected at higher time scales.
CARB Off-Road Low NOx Demonstration Program - Engine Calibration and Initial Test Results
Authors: Neely Gary , Sharp Christopher , Adsule Kartik , Zavala Bryan
Published: April 2024

Off-road diesel engines remain one of the most significant contributors to the overall oxides of nitrogen (NOX) inventory and the California Air Resources Board (CARB) has indicated that reductions of up to 90% from current standards may be necessary to achieve its air quality goals. In recognition of this, CARB has funded a program aimed at demonstrating emission control technologies for off-road engines. This program builds on previous efforts to demonstrate Low NOX technologies for on-road engines. The objective was to demonstrate technologies to reduce tailpipe NOX and particulate matter (PM) emissions by 90 and 75%, respectively, from the current Tier 4 Final standards. In addition, the emission reductions were to be achieved while also demonstrating a 5 to 8.6% carbon dioxide (CO2) reduction and remaining Greenhouse Gas (GHG) neutral with respect to nitrous oxide (N2O) and methane (CH4). This paper focuses on the engine calibration efforts for aftertreatment (AT) thermal management and improved fuel economy which included a diesel Dynamic Skip Fire (dDSF™) calibration. Test results obtained with a development-aged (hydrothermal aging only) AT system over the applicable off-road test cycles and a low load cycle are presented. The emission control system and modified calibrations could achieve internal tailpipe (TP) NOX development targets with technologies suitable for production, allowing for a significant potential compliance margin. The level of CO2 reduction was dependent on the test cycle with the target achievable without dDSF for all cycles except for the RMC where a 4% reduction was observed. The addition of dDSF reduced cycle CO2 by an additional 0.5 to 3%, depending on the test cycle, and maintained higher AT temperatures which reduced the use of AT thermal management modes.
Fuzzy Control of Regenerative Braking on Pure Electric Garbage Truck Based on Particle Swarm Optimization
Authors: Zhang Yu
Published: April 2024

To improve the braking energy recovery rate of pure electric garbage removal vehicles and ensure the braking effect of garbage removal vehicles, a strategy using particle swarm algorithm to optimize the regenerative braking fuzzy control of garbage removal vehicles is proposed. A multi-section front and rear wheel braking force distribution curve is designed considering the braking effect and braking energy recovery. A hierarchical regenerative braking fuzzy control strategy is established based on the braking force and braking intensity required by the vehicle. The first layer is based on the braking force required by the vehicle, based on the front and rear axle braking force distribution plan, and uses fuzzy controllers. Achieve one-time distribution of the front axle braking force; the second layer, according to the magnitude of the braking intensity, divides the braking conditions into light braking, moderate braking and emergency braking, and realizes braking under the three working conditions respectively. Secondary distribution of front axle braking force. Using the driving mileage contribution as the evaluation index and NEDC as the simulation working condition, it is verified that the regenerative braking control strategy can achieve energy recovery. To further improve the braking energy recovery and ensure the vehicle braking effect, the braking effect and braking energy recovery are used as the optimization objective function, the particle swarm algorithm is used to optimize the fuzzy rules, and the optimized fuzzy controller is reloaded into the regenerative braking control Simulation is carried out in the strategy to verify that the designed multi-section front and rear wheel braking force distribution curves and fuzzy rules optimized by particle swarm algorithm can effectively improve regenerative braking energy recovery and improve vehicle driving range, while ensuring braking safety.
Model Based Algebraic Weight Selection for LQI Control Reducing Dog Clutch Engagement Noise
Authors: Piracha Muddassar , Grauers Anders , Hellsing Johan
Published: April 2024

This paper presents a feedback control strategy to minimize noise during dog clutch engagement in a hybrid transmission. The hybrid transmission contains an internal combustion engine(ICE) and 2 electric motors in P1 and P3 configurations. For efficiency during driving, at high vehicle speeds ICE is connected to wheels, via the dog clutch, hence shifting the vehicle from series to parallel hybrid mode. It is shown by experimental results that if the speed difference between the two sides of the dog clutch is below a certain level the engagement will be without clonk noise. In this paper the designed state feedback Linear Quadratic Integral (LQI) control provides the synchronization torque request to the P1 motor, hence matching the speed of one side of dog clutch with the other under the disturbance from combustion torque of the engine. Normally LQI controllers are tuned by trial-and-error methods, but this paper presents an algebraic approach where the feedback gains of the LQI controller are calculated based solely upon the physical parameters of the system, the required time for speed synchronization and acceptable values of speed difference from experimental results. This approach minimizes the need for manual tuning and can deliver the controller gains for any size and version of the transmission by just modifying the parameter values and functional requirements. The results are shown by simulations on a 2DOF torsional system representing ICE, dual mass flywheel and P1 electric motor.
Design Methodology for Efficient Electrified Powertrains Applied to Customer Technical Need Identification
Authors: Couillandeau Matthieu , El Ganaoui-Mourlan Ouafae , Miliani El Hadj , Carlos Da Silva Daniel , Oussedik Nassila , Lombard Tristan , Mendes Alves Breno
Published: April 2024

Radical greenhouse gases emissions reduction necessity is bringing deep evolution in mobility behaviors and is the core reason for a significant diversification of automotive powertrain technologies, making it more and more complex for customers to find the best suited technology. This paper proposes a customer-oriented approach that translates needs into technical requirements that can be used as choice guidelines. First, customers answer a small survey on their driving habits and the class of car they want. Real life driving cycles are then recorded, and Simulink simulations, based on lowest equivalent consumption calculations, allow to identify and size an ideal powertrain that can then become a benchmark for vehicle final selection. As a methodology development step, this paper focused on Battery Electric Vehicle (BEV), Hybrid Electric Vehicle (HEV) and Fuel Cell Electric Vehicle (FCEV), and on two case studies: a customer driving in urban areas with a small city car, and another one who needs the space of a SUV for frequent highway trips, the former advised to choose a BEV with a small battery, the latter a FCEV. Investigation of more complex case studies would then only require enriching the inputs of the method, adding other architectures and other key choice parameters, such as the availability and cost of energy (charging station at work, H2 fueling stations nearby), total cost of ownership, and the availability of alternative mobility solutions for punctual transportation needs, still relying on the basic principles illustrated in this paper.
Exploring Optimization Opportunities for Battery Electric Vehicle Compact Powertrains by Enhancing Power Density to Meet Customer Demand
Authors: Villarreal Jaret
Published: April 2024

The rapid evolution of battery electric vehicle (BEV) development has highlighted the need to develop BEVs that meet customer demands for both high-performance and space-efficiency. This paper explores the optimization opportunities available within the landscape of BEV powertrains, focusing on the power-dense potential of single-axis powertrain systems. The need to adhere to power density requirements to accommodate performance aspirations while simultaneously yielding more cabin or storage space to the customer creates a challenging problem for designers. With this pursuit, these competing interests must strike a harmonious balance to create the best experience for the customer. The subject of this study is an investigation into a leading competitor's powertrain that explores the potential optimization opportunities available within its already compact single-axis electric transmission. The methodology entails a reverse-engineered model of the geartrain, enabling an outsider’s assessment of the gear durability responses experienced by the actual system. An in-house optimization workflow is then leveraged that can explore the feasibility of further size reduction while upholding the standards exhibited by the existing system. Insights into the workflow process and software employed are presented while analysis of the optimization outputs is examined. In conclusion, the findings provide a glimpse into the ability for the BEV transaxle design process to consider optimization at earlier stages in development. This study aims to highlight the need for continuous improvement in design by addressing the feasibility of attaining a more compact yet resilient powertrain. By leveraging an intelligent optimization workflow, the paper determines whether a compact production powertrain yields any additional room for improvement. With current technological advancements allowing for engineers to simultaneously pursue many competing objectives such as efficiency, NVH, durability, size, and cost into unique workflows, designs that bring the best driving experience for our customers can be delivered.
Design Development and Weight Optimization of Crankshaft for Commercial Vehicle Application
Authors: Khandelwal Meha , Kaundabalaraman Kaarthic , Rathi Hemantkumar
Published: April 2024

In crank- train system, the prime objective of crankshaft is to facilitate the transformation of reciprocating motion of connecting rod into rotational motion at flywheel end. Moreover, the contribution of mass from crankshaft is in the same order as of flywheel assembly mass which accounts to approximately 40% to 50% of total mass of engine. Therefore, to accomplish the development of an efficient engine it is vital to optimize the crankshaft based on simulation parameters like balance rate, mass, torsional frequency, web shear stress etc. In the given work, crankshaft has been designed and developed for an engine used in light duty commercial vehicle. The defined work demonstrates the application of 1D simulation tool AVL Excite in development phase of the engine. To establish equilibrium between the weight and simulation guidelines, many iterations of models were evaluated and finally we were able to achieve mass reduction of nearly 8% from the base model. Thenceforth, validation of the entire system was executed for bearing, torsional and strength parameters first in AVL Excite and then in engine test bed. The validation phase is under progress and initial trials are showing no issues, in parallel fatigue test is planned for further design validation.

Additionally, as an initiative we have considered hollow crankshaft technology concept for better reduction in weight of crankshaft. Soft simulation has been completed and further process of part development is in progress, the work highlights in detail and necessary reference used for developing the concept.
Influence of Microstructure on CFD Simulation of Water Removal in a PEM FC Channel
Authors: Antetomaso Christian , Merola Simona Silvia , Irimescu Adrian , Vaglieco Bianca Maria , Jannelli Elio
Published: April 2024

Water removal from Proton Exchange Membrane (PEM) Fuel Cell (FC) mainly involves two phenomena: some of the emerging droplets will roll on the Gas Diffusion Layer (GDL), others may impact channel walls and start sliding along the airflow direction. This different behaviour is linked to the hydrophobic/hydrophilic nature of the surface the water is moving on. In this paper, the walls of the channel of a FC were characterized by applying optical techniques. The deposition of droplets on the channel wall led to an evaluation of the proper range for Contact Angle Hysteresis (CAH = 55° - 45°), and due to the high wettability of the surface, droplets dimension was defined with a dimensionless parameter B/H. Under high crossflow condition (15 m/s) a sliding behaviour was observed. The channel features determined through image processing were used as boundary conditions for a 2D CFD two phase simulation employing the Volume of Fluid (VOF) model to keep track of the fluids interface. A droplet was initialized on the wall and its behaviour was observed under 15 m/s airflow. Starting from the values observed experimentally, three different contact angle strategies were adopted to manage the liquid-solid-gas interface: static contact angle, quasi-dynamic contact angle and dynamic contact angle. The calculated sliding velocity was validated against experimental data. The static contact angle led to an overestimation of water removal capability. The quasi-static approach improved the accuracy of the simulation, but only the dynamic contact angle consistently falls inside the error bars of experimental measurements. Moreover, bigger droplets show higher sensitivity to contact angle boundary conditions.
Characteristic Frequency Screening of Electrochemical Impedance Spectroscopy in Proton Exchange Membrane Fuel Cells Based on Genetic Algorithm
Authors: Guan Peng , Shen Yitao , Wang Zheyu , Bai YuXin , Ji ZhaoQi
Published: April 2024

In the diagnosis of membrane flooding and drying faults in a Proton Exchange Membrane Fuel Cell (PEMFC) through Electrochemical Impedance Spectroscopy (EIS), this paper proposes a Genetic Algorithm (GA)-based feature selection method for selecting the required frequency points of failure, to reduce the measurement time taken by EIS while ensuring high diagnostic accuracy. This feature selection method searches the feature space through GA and proposes an encoding method tailored to this problem. During the searching process, three algorithms, i.e., Backpropagation Neural Network (BPNN), K-Nearest Neighbor (KNN), and eXtreme Gradient Boosting (XGBoost), are used to extract various features and select higher diagnostic rates of feature frequencies. Comparisons are made between the feature frequencies selected by the proposed method and those selected by conventional methods based on empirical experience, and it is found that the feature frequencies selected by the proposed method have better diagnostic performance.
Revealing the Impact of Mechanical Pressure on Lithium-Ion Pouch Cell Formation and the Evolution of Pressure During the Formation Process
Authors: Xu Wentao , Zhu Jiangong , Zhang Jie , Jin Yiqun , Wang Xiuwu , Wei Xuezhe , Dai Haifeng
Published: April 2024

The formation is a crucial step in the production process of lithium-ion batteries (LIBs), during which the solid electrolyte interphase (SEI) is formed on the surface of the anode particles to passivate the electrode. It determines the performance of the battery, including its capacity and lifetime. A meticulously designed formation protocol is essential to regulate and optimize the stability of the SEI, ultimately achieving the optimal performance of the battery. Current research on formation protocols in lithium-ion batteries primarily focuses on temperature, current, and voltage windows. However, there has been limited investigation into the influence of different initial pressures on the formation process, and the evolution of cell pressure during formation remains unclear. In this study, a pressure-assisted formation device for lithium-ion pouch cells is developed, equipped with pressure sensors. This device allows for precise adjustment of the initial pressure during cell formation and enables the recording of pressure evolution. Employing the initial pressure as a variable, five groups of pouch cells are subjected to distinct initial pressure settings for individual formation processes. Simultaneously, the pressure evolution signals during formation are meticulously recorded. The results reveal that applying an appropriate initial pressure (0.05/0.1 MPa) during the formation resulted in a capacity enhancement of over 2% for the pouch cells, accompanied by significantly improved consistency. Conversely, both inadequate and excessive pressure adversely affect the capacity of the battery. The effectiveness of the formation is analyzed using rate capability testing, electrochemical impedance spectroscopy (EIS) testing, battery disassembling, and scanning electron microscopy (SEM). Additionally, the pressure evolution during formation is scrutinized to track the growth of the SEI from a unique perspective.
Parameterization of an Electrochemical Battery Model Using Impedance Spectroscopy in a Wide Range of Frequency
Authors: Chen Chao , Wurzenberger Johann
Published: April 2024

The parameterization of the electrochemical pseudo-two-dimensional (P2D) model plays an important role as it determines the acceptance and application range of subsequent simulation studies. Electrochemical impedance spectroscopy (EIS) is commonly applied to characterize batteries and to obtain the exchange current density and the solid diffusion coefficient of a given electrode material. EIS measurements performed with frequencies ranging from 1 MHz down to 10 mHz typically do not cover clearly isolated solid state diffusion processes of lithium ions in positive or negative electrode materials. To extend the frequency range down to 10 μHz, the distribution function of relaxation times (DRT) is a promising analysis method. It can be applied to time-domain measurements where the battery is excited by a current pulse and relaxed for a certain period. By means of curve-fitting techniques, the pulse-relaxation measurement can be transferred in a function suitable for the DRT analysis, which is the basis for constructing additional low-frequency impedance points.

In this work, the EIS measured in the frequency domain and the simulated EIS derived from the time-domain measurement by the DRT method are combined to cover all electrochemical processes of the battery, especially the lithium-ion diffusion in the electrodes. The electrical equivalent circuit model (ECM) consisting of resistors, ZARC elements and Warburg elements in the frequency domain is applied to fit the EIS curve and identify the P2D model parameters. By investigating the intercalation processes using the distribution function of the differential capacity (DDC) technique, particles with different particle sizes are considered and their corresponding solid diffusion coefficients are identified by the established ECM. The consistency between time- and frequency-domain data is elaborated based on a model of a commercial automotive cell.
Parameters Affecting Torsional Stiffness of Vehicle Doors
Authors: Goyal Vinay Kumar , Selvan Veera , Pandurangan Venugopal , Unadkat Siddharth , Almeida Neil Ricardo
Published: April 2024

Side doors are pivotal components of any vehicle, not only for their aesthetic and safety aspects but also due to their direct interaction with customers. Therefore, ensuring good structural performance of side doors is crucial, especially under various loading conditions during vehicle use. Among the vital performance criteria for door design, torsional stiffness plays an important role in ensuring an adequate life cycle of door. This paper focuses on investigating the impact of several door structural parameters on the torsional stiffness of side doors. These parameters include the positioning of the latch, the number of door side hinge mounting points on doors (single or double bolt), and the design of door inner panel with or without Tailor Welded Blank (TWB) construction. The findings of this study reveal that the change in latch position has the most significant influence on torsional stiffness, followed by the removal of TWB from the inner panel, upon implementation of suitable local hinge reinforcements in TWB removed design, torsional stiffness enhances significantly. While decreasing the number of hinge mountings from a double bolt to a single bolt configuration does affect torsional stiffness, it has the least impact among these three parameters. All these parameters are very useful from vehicle architectural, weight optimization and assembly process aspects and consideration of same would lead to optimized door design with less weight and cost.
Responses to Flashing Warning Lights and Colors of Service Vehicles
Authors: Bullough John D. , Skinner Nicholas P. , Rea Mark S.
Published: April 2024

Flashing warning lights and vehicle markings of various colors are used on a wide range of emergency and other service vehicles to help inform drivers about the presence of these vehicles and the types of situations that drivers are approaching. Although not applied consistently among all jurisdictions, the colors and performance of these visual elements are often selected to help communicate the type of scenario (such as red flashing lights to indicate an emergency vehicle, or yellow flashing lights to indicate a non-emergency service vehicle). Previous investigations have shown that flashing light colors, vehicle and marking colors, and flashing temporal characteristics (e.g., rapid versus slower flashing) can all affect a driver’s perception of whether a vehicle along the road is responding to an emergency situation or not. Building on previous research, a laboratory study was carried out to investigate how drivers perceive scale-model roadway scenarios including different numbers of vehicles varying in their colors, and with flashing lights modulating at different intensity levels and flash frequencies. For each scenario, observers were asked whether as drivers they would proceed with caution past the scene or prepare to slow down or stop. Observers’ responses were recorded, and the time taken to provide a response was also recorded as a measure of certainty/uncertainty. Overall, the results show that coordinating the presence and color of flashing lights with the colors of vehicles and their markings are among the primary cues used by drivers to assess whether a roadside incident scene is an emergency situation or not. The results also provide suggestions for using flashing lights when multiple vehicles are present to reinforce consistent judgments among drivers.
Performance of Headlights Fitted with LED Replacement Bulbs
Authors: Bullough John D. , Skinner Nicholas P.
Published: April 2024

To ensure adequate visibility without excessive glare, vehicle headlights are designed to use a specific source of illumination. The optical designs of headlights gather the luminous flux produced by the light source to produce a useful beam pattern that meets the relevant requirements and standards for vehicle forward lighting. With the advent of solid state, light emitting diode sources for general illumination, an increasing number of LED replacement headlight bulb products has emerged over the past decade. In most cases, these LED replacement bulbs are not permitted for legal use on public roadways, but some countries have begun to permit specific LED replacement bulbs to be used legally on the road for specific makes, models and production years of certain vehicles. If they can be demonstrated to produce a beam pattern that meets the photometric requirements for a legal headlight, they are permitted to be used legally for on-road use. In the present paper we present photometric measurement data for two North American headlight systems originally designed for halogen bulbs. Each was fitted with a halogen bulb and with two different LED replacement bulbs and measured at specific angles to check photometric compliance with the minimum and/or maximum luminous intensity at those angles. We also present data on the illuminances produced at several locations along a hypothetical roadway to compare performance between the headlights with halogen bulbs and with each LED bulb.
Comparison of Bake Hardening Effects on AHSSs and Extruded Aluminum Alloys Applied in BEV Reinforcement Structures
Authors: Hu Jun , Sun Yeting , Yu Miao , Wang Yu-Wei , Thomas Grant
Published: April 2024

At the dawn of battery electric vehicles (BEVs), protection of automotive battery systems as well as passengers, especially from severe side impact, has become one of the latest and most challenging topics in the BEV crashworthiness designs. Accordingly, two material-selection concepts are being justified by the automotive industry: either heavy-gauge extruded aluminum alloys or light-gauge advanced high-strength steels (AHSSs) shall be the optimal materials to fabricate the reinforcement structures to satisfy both the safety and lightweight requirements. In the meantime, such a justification also motivated an ongoing C-STARTM (Cliffs Steel Tube as Reinforcement) Protection project, in which a series of modularized steel tube assemblies, were demonstrated to be more cost-efficient, sustainable, design-flexible, and manufacturable than the equivalent extruded aluminum alloy beams as BEV reinforcement structures. Tangent to this comparative study, the present work shed some light on the bake hardening (BH) effects during a paint-baking cycle, which was a necessary processing procedure for a body-in-white (BIW), on some representative AHSSs and extruded aluminum alloys via various coupon-level mechanical experiments under precise in-situ strain/displacement and temperature control conditions at multiple strain rates and stress states. The corresponding material mechanisms were also reviewed and explained. Eventually, the test results revealed some tremendously distinct changes induced by the BH effects on the two types of metallic materials: the baking-induced Cottrell atmosphere could effectively enhance the strength without weakening the local ductility of the target AHSS, while the baking-induced precipitation slightly hardened the selected aluminum alloy yet lowered its fracture limit. Such a distinction further indicated the advantages of the AHSSs in this application. The ultimate objective of this work was to provide relative references for future finite element simulations and BEV structural designs.
A Study on Handling Steering Angle Sensor Failure on Redundancy-Based EPS Systems
Authors: Jeong Sangwoo , Kim Taegyun , Kim Daesung
Published: April 2024

A redundant system refers to a system that operates identical unit systems simultaneously to enhance robustness to fault. In particular, considering system complexity, a redundant system consisting of two identical unit systems is widely used. However, dual-system redundancy can detect the presence of malfunction when the outputs of the two unit systems differ, but it is challenging to identify the normally functioning unit system. Therefore, the functionality can degrade or be interrupted even when a normally operating unit system is present. Hence, research is actively ongoing to address the challenge of identifying the normally functioning unit system. This study proposes an algorithm to identify the normally operating sensor in the event of a steering angle sensor fault in a redundant Electronic Power Steering (EPS) system. In this paper, an Extended Kalman Filter is designed based on the Bicycle model of vehicle dynamics to estimate the steering angle of the steering wheel. Real-time driving data for estimation is acquired through CAN communication inside the vehicle. By comparing estimated values with actual sensor outputs, the algorithm discern sensor faults from normal operation and maintain the steering assist function when a normally functioning sensor is in present. The proposed steering angle estimation algorithm and failure determination algorithm were verified with driving data obtained from an actual vehicle. To evaluate the algorithm, a disturbance was applied to one sensor to simulate a failure. The experimental results demonstrated that the steering assistance function is maintained even when one sensor malfunctions.
The Ultimate Bending Resistance of Thin-walled Square Tube with Strengthened Ridgelines
Authors: Zheng Yuqing , Cui Yongquan , Yang Minghao
Published: April 2024

By introducing the yield strength ratio λ of strengthened ridgeline to plate and the strengthening coefficient multiplier R, the theoretical prediction expression of maximum bending moment of thin-walled square tube with strengthened ridgelines under static cantilever bending condition is obtained. Then the software of Hypermesh 13. 0 was used to establish two quasi-static finite element simulation comparison models under the corresponding static cantilever conditions. One model was designed for the original material thin-walled square tube, and another one was designed for the thin-walled square tube with strengthened ridgelines. After that, the LS-DYNA 971 solver was introduced to perform the solution calculations. Through a series of simulation calculations and result analysis, the accuracy of the theoretical expression for the maximum bending moment of a thin-walled square tube with strengthened ridgelines was verified. The simulation results of the maximum bending moment are in good agreement with the corresponding theoretical predictions, and the maximum deviation is less than 10%. The simulation results and deviation analysis show that for a thin-walled square tube with a section size of 56. 36*56. 36mm and a wall thickness of 1. 0mm, when the yield strength ratio λ of strengthened ridgeline to plate is about 4, and the section strengthening areas of four ridgelines account for 9%, the maximum bending moment can be increased by about 27%.
XiLS (X in the Loop Simulation) Based Thermal Management Development
Authors: Lim Taewoong , Baek Junho , Dongmyeong Lee , Jeon Jee Hwan , Lee Hyeonseob , Park Junhyeong , Myeong Hanseung , Kim Myeongwoo , Choi Seockhwan
Published: April 2024

The significance of thermal management performance in electric vehicles (EVs) has grown considerably, leading to increased complexity in thermal systems and a rapid rise in safety and quality-related concerns. The present real-vehicle-based development methods encounter several constraints in their approach when dealing with highly complex systems. Huge number of verification and validation work To overcome these limitations and enhance the thermal system development process, a novel virtual development environment established using the XiLS (X in the Loop Simulation) methodology. This XiLS methodology basically based on real-time coupling between physical thermal system hardware and analytical models for the other systems of vehicle. To control vehicle model and thermal system, various options were realized through hardware, software and model for VCU (Vehicle control unit) and TMS (Thermal management system) control unit. With XiLS evaluation environment as the foundation, conventional air conditioning test such as cabin cooling /heating and component cooling performance were evaluated even without real test vehicle. Furthermore, calibration of thermal management system control was performed, which resulted in partial improvement in energy efficiency. EV driving range and energy efficiency for cold ambient condition (-7°C) were evaluated based on homologation drive cycle tests, such as the MCT (Multi-cycle test) according to the US EPA protocol. The comprehensive evaluation work was conducted during the developmental phase of new electric vehicle projects before SOP, which demonstrated the effectiveness of this proposed methodology.
Analysis and Design of Suspension State Observer for Wheel Load Estimation
Authors: Zeng Tianyi , Liu Zeyu , He Chenyu , Zeng Zimo , Chen Haotian , Zhang Feiyang , Fu Kai , Chen Xinbo
Published: April 2024

Tire forces and moments play an important role in vehicle dynamics and safety. X-by-wire chassis components including active suspension, electronic powered steering, by-wire braking, etc can take the tire forces as inputs to improve vehicle’s dynamic performance. In order to measure the accurate dynamic wheel load, most of the researches focused on the kinematic parameters such as body longitudinal and lateral acceleration, load transfer and etc. In this paper, the authors focus on the suspension system, avoiding the dependence on accurate mass and aerodynamics model of the whole vehicle. The geometry of the suspension is equated by the spatial parallel mechanism model (RSSR model), which improves the calculation speed while ensuring the accuracy. A suspension force observer is created, which contains parameters including spring damper compression length, push rod force, knuckle accelerations, etc., combing the kinematic and dynamic characteristic of the vehicle. Subsequently, the wheel load can be obtained by solving the above nonlinear system using Extended Kalman Filtering (EKF). Validation experiments are conducted on a quarter-suspension model as well as a Formula Student race car under standard working conditions. The car is equipped with sensors for the signals required by the algorithm as well as signal processing units. While calculations are performed, the conventional acceleration-based estimation method is used for comparison. The experimental results show that the measurement error of the method in this paper is significantly smaller than that of the traditional method, and it has higher sensitivity to dangerous conditions such as bumps and rollovers, which is of greater significance for the usage of wheel load for vehicle control and active safety.
Evaluation of Semi-Active Vehicle Suspension System Performance Incorporating Magnetorheological Damper Using Optimized Feedback Controller Based on State-Derivative
Authors: M.Faragallah Mohamed , Metered Hassan , Abdelaziz Taha H.
Published: April 2024

The purpose of this paper is to investigate the efficiency of a quarter car semi-active suspension system with the state-derivative feedback controller using the Bouc-Wen model for magneto-rheological fluids. The magnetorheological (MR) dampers are classified as adaptive devices because of their characteristics can be easily modified by applying a controlled voltage signal. Semi-active suspension with MR dampers combines the benefits of active and passive suspension systems. The dynamic system captures the basic performance of the suspension, including seat travel distance, body acceleration, passenger acceleration, suspension travel distance, dynamic tire deflection and damping force. With minimal reliance on the use of sensors, the investigation aims to improve ride comfort and vehicle stability. In this study, the state derivative feedback controller and Genetic algorithm (GA) is utilized to improve the performance of semi-active suspension system. Moreover, the cost is reduced compared to the passive suspension and the active suspension systems in which sensors and actuators are used. The performance of the semi-active suspension is represented by applying the road profile to the system. This is accomplished by simulating and analyzing system performance using MATLAB and SIMULINK. Initial results show an improvement in the semi-active system, which includes both the passive suspension system without any control system and the active suspension system with a PID controller.
An Active Suspension Control Strategy for Planet Rover on Rough Terrain
Authors: Liu Jun , Zhang Kaidi , Shi Junwei , Wu Jinglai , Zhang Yunqing
Published: April 2024

The soft and rough terrain on the planet's surface significantly affects the ride and safety of rovers during high-speed driving, which imposes high requirements for the control of the suspension system of planet rovers. To ensure good ride comfort of the planet rover during operation in the low-gravity environment of the planet's surface, this study develops an active suspension control strategy for torsion spring and torsional damper suspension systems for planet rovers. Firstly, an equivalent dynamic model of the suspension system is derived. Based on fractal principles, a road model of planetary surface is established. Then, a fuzzy-PID based control strategy aimed at improving ride comfort for the planet rover suspension is established and validated on both flat and rough terrains. This study provides an advanced suspension system control strategy for planet rovers' ride comfort and safety during high-speed driving, ensuring the smooth operation of vehicles on the rough extraterrestrial terrain.
Road Feel Modeling and Return Control Strategy for Steer-by-Wire Systems
Authors: Chen Chaoning , Kaku Chuyo , Zheng Hongyu
Published: April 2024

The steer-by-wire (SBW) system, an integral component of the drive-by-wire chassis responsible for controlling the lateral motion of a vehicle, plays a pivotal role in enhancing vehicle safety. However, it poses a unique challenge concerning steering wheel return control, primarily due to its fundamental characteristic of severing the mechanical connection between the steering wheel and the turning wheel. This disconnect results in the inability to directly transmit the self-aligning torque to the steering wheel, giving rise to complications in ensuring a seamless return process. In order to realize precise control of steering wheel return, solving the problem of insufficient low-speed return and high-speed return overshoot of the steering wheel of the SBW system, this paper proposes a steering wheel active return control strategy for SBW system based on the backstepping control method. First, the dynamics model of the SBW system is established, thereby laying the foundation for further analysis. Next, an active return judgment logic based on steering wheel angle, driver torque and the change rate of driver torque to make informed decisions regarding return control is proposed. Then, the active return control algorithm based on the backstepping control method is designed and the stability analysis of this algorithm is provided to ensure its reliability in practice. At last, the effectiveness of the steering wheel active return control strategy is evaluated by simulations and hardware-in-the-loop test. The results show that the return control strategy can accurately judge the return time and have a relatively good return effect with the low-speed return deficiency and high-speed return overshoot of steering wheel be alleviated.
Identification of Important Issues and Driving Modes for Enhancing NVH Performance of Electric Vehicles Based on Comparative Analysis of User Experience with Conventional ICE Vehicles
Authors: Mise Shion , Torii Kenji , Sellerbeck Philipp , Hank Stefan , Iwano Hidetaka , Nishikoji Takuya
Published: April 2024

The challenges concerning noise, vibration, and harshness (NVH) performance in the vehicle cabin have been significantly changed by the powertrain shift from a conventional drive unit with an internal-combustion engine (ICE) to electric drive units (eAxles). However, there is few research regarding the impact of electrification on NVH considering the influence of the context such as multi-stimuli and traffic rules during a real-life driving.

In this study, the authors conducted test drives using EVs and ICEVs on public roads in Europe and conducted a statistical analysis of the difference in driver impression of NVH performance based on interviews during actual driving. The impression data were categorized into clusters corresponding to related phenomena or features based on driver comments. Furthermore, the vehicles data (vehicle speed, acceleration, GPS information, etc.) were recorded to associate the driver impressions with the vehicle’s conditions when the comments were made.

Through the statistical analysis of driver’s impression and comments, this study has revealed that the most important factor in improving the NVH marketability of EVs is the enhancement of acoustic phenomena, particularly addressing issues related to whine and whistling noises generated by eAxles. Based on the results regarding the association between a driver's impression and driving conditions, the shift to EVs expands the range of driving conditions in which the whine and whistling noises make a negative impression on drivers, specifically during acceleration and at higher vehicle speeds. Additionally, these noises are less correlated with driver feedback regarding vehicle behavior. Whereas, for achieving improvements of whine and whistling noises, the comprehensive management of the acoustic environment is indispensable, because these noises are masked by road noise and wind noise.
Experimental Study on Engine Performance Fueled with Ammonia-Hydrogen Blend Ignited by Diesel Pilot
Authors: Akram Muhammad Saad , Cheng Qiang , Yeganeh Maryam , Kaario Ossi , Larmi Martti
Published: April 2024

The global energy crisis and drastic climate change are continuously promoting the implementation of sustainable energy sources. To meet the emission standards and carbon-neutrality targets in vehicle industry, ammonia is considered to be one of the promising carbon-neutral fuels. However, running the engines on high amounts of ammonia may lead to significantly high ammonia slip. This originates huge safety concerns. Therefore, hydrogen is added in certain ratio with ammonia to promote combustion and reduce ammonia slip. Furthermore, adding diesel as a pilot fuel further facilitates the combustion reactions. This experimental study investigated the effect of different ammonia-hydrogen blend ratios on in-cylinder pressure, heat release rate, cumulative heat release, indicated mean effective pressure (IMEP), indicated thermal efficiency (ITE), CA5 and CA50. This effect of blend ratios was tested for varied diesel pilot amounts and timings. The results show that increasing the hydrogen amount in ammonia-hydrogen blend from 20% to 40% (by vol.) increased the in-cylinder pressure and heat release rate. In addition, significant increasing trend for cylinder pressure and heat release rate was observed by increasing the diesel pilot amount from 5% to 10% to 20% (by vol.) and pilot timing from 9 to 11 and 13 DBTDC. Furthermore, increasing the diesel pilot amount increased the IMEP and ITE.
Advanced Aftertreatment System Meeting Future HD CNVII Legislation
Authors: Wang Yan , Chen Shuyue , Zhang Jun , Chen Junyin , Long Lucas , Geisselmann Andreas , Bender Michael , Tao Zemin , Zhu Minlin
Published: April 2024

Options for CNVII emission legislation are being widely investigated in a national program organized by China Vehicle Emission Control Center (VECC) since early 2020. It is foreseen that this possibly last legislation in China will have more stringent emission requirements compared to CNVI, including among other changes especially a further reduction of nitrogen oxide (NOx), inclusion of nitrous oxide (N2O) and sub-23 nm particle number (PN).

This study investigates the technical feasibility to fulfill a CNVII emission legislation scenario, based on a modified CNVI 8 L engine operating under both cold and hot World Harmonized Transient Cycle (WHTC) and Low Load Cycle (LLC). Methods to address the challenges are discussed and validated, including application of a twin dosing system, electric heater, hybrid concepts of combining Copper (Cu-), Iron (Fe-) and Vanadium (V-) SCR technologies, filters with ultra-high filtration efficiency and optimization of engine calibration and urea dosing strategies.

Based on the results, an advanced aftertreatment system is then proposed that can meet the requirements of the discussed CNVII scenario.
Investigation of Injection Strategy on Combustion and Emission Characteristics in a GDI Engine with a 50 MPa Injection System
Authors: Wang Tong , Lou Diming , Zhao Yinghua , Zhang Yunhua , Tan Piqiang , Hu Zhiyuan , Fang Liang
Published: April 2024

A DMS500 engine exhaust particle size spectrometer was employed to characterize the effects of injection strategies on particulate emissions from a turbocharged gasoline direct injection (GDI) engine. The effects of operating parameters (injection pressure, secondary injection ratio and secondary injection end time) on particle diameter distribution and particle number density of emission were investigated. The experimental result indicates that the split injection can suppress the knocking tendency at higher engine loads. The combustion is improved, and the fuel consumption is significantly reduced, avoiding the increase in fuel pump energy consumption caused by the 50 MPa fuel injection system, but the delayed injection increases particulate matter emissions. In terms of particulate matter emissions, increasing the excess air ratio, advancing direct fuel injection, increasing fuel injection pressure, and delaying ignition timing will all lead to the reduction of the particulate matter emissions. The emission results also demonstrate that an increase in fuel injection pressure from 35 MPa to 50 MPa significantly reduces the particle number (PN) of all particle size segments, which has a significant effect on reducing the number of accumulated particles, and the PN concentration is reduced by more than 20%. At 1500r/min 15 bar working condition, triple injection strategy with 50MPa injection pressure, the PN is reduced by 41% compared with the base engine, and fuel consumption is increased by 0.8%. The characteristics of gas emissions are mainly to provide guidance for the selection of injection strategy to avoid excessive deterioration of gas emissions while optimizing particulate matter emissions and fuel consumption. The optimal particulate emission characteristic is obtained at the last injection end timing of 90°CA.