bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrically Heated Mixer for Near-Zero Urea Deposit
Authors: Vernham Bruce , Kadam Vaibhav , Masoudi Mansour , Noorfeshan Sahm , Poliakov Nick
Published: April 2024

When used with injecting urea-water solution forming ammonia, Selective Catalytic Reduction (SCR) catalyst is a proven technology for greatly reducing tailpipe emission of nitrogen oxides (NOx) from Diesel engines. However, one major shortcoming of an SCR-based system is forming damaging urea deposits (crystals) in low temperature exhaust operations, especially exacerbated during lower exhaust temperature operations or higher injection rates. Deposits reduce SCR efficiency, damage exhaust components, and induce high concentration ammonia slips.

We describe here an Electrically Heated Mixer (EHM™) demonstrated on a Diesel engine markedly inhibiting deposit formation in urea SCR systems, both in low (near 200 °C) and higher exhaust temperature operations and for both low and high urea injection rates in various, realistic engine operations. Engine test runs were conducted in long durations, 10 to 20 hours each, for a total of nearly 100 hours. In nearly all operation modes, EHM maintained deposits below 1% of the total injected DEF mass; most were below 0.5%, practically non-existent, including when in higher injection rates. To further gain confidence in and validate the deposit-free outcome due to the EHM impact, CFD simulations of the same exhaust conditions were performed, which further confirmed EHM’s capability in substantially inhibiting urea deposits observed on the engine.

Along with prior publications, this work forms a trilogy demonstrating EHM enabling rapid heat-up making available several-fold lower tailpipe NOx, meeting ultra-stringent NOx regulations (e.g., Californian/EPA 2027 meeting 0.02 gr/bhp.hr), reducing tailpipe NOx in various regulatory and non-regulatory cycles [Frontier, 2022] while enabling highly efficient NOx conversion in low-load cycles and in fast transients [Topics in Catalysis, 2022, COMVEC, 2022].
Research on the Flow and Heat Exchange Performance of the Chiller for Electric Vehicles
Authors: Sun Ming , Kang Yingzi , Wang Mengmeng , Shangguan Wen-Bin
Published: April 2024

A set of enthalpy difference test equipment is set up to test flow and heat exchange performance of chillers. The empirical correlations for the convective heat transfer coefficients on the coolant side and the refrigerant side are obtained by fitting the test data, and a two-particle lumped parameter model of the chiller is established. Based on this, the heat exchange performance of the chiller under different operating conditions is given. The effects of herringbone corrugated plate parameters, including angle, pitch, and depth, on flow and heat exchange performance of chillers under different flow rates are further studied. Using the Wilson plot method in test design, the thermal resistance of convective heat transfer on each side is separated from the total thermal resistance to calculate the convective heat transfer coefficient. In fitting the boiling convective heat transfer coefficient on the refrigerant side, various boiling behaviours within the two-phase zone are considered, and critical value distinguishing dominant boiling behaviours is quantitatively determined. In the modelling of chillers, two-phase and overheated zones of the refrigerant are considered simultaneously, and their area sizes are calculated to enhance the accuracy of the model. The study on the influence of chiller structural parameters on flow and heat exchange performance shows that within a certain range, the chevron angle is positively correlated with pressure drop and Nu, while the chevron pitch and depth are negatively correlated with pressure drop and Nu. As Reeq increases, the correlations between pressure drop and structural parameters become more significant. Insights on chiller design can be gained from this study.
3-Dimentional Numerical Transient Simulation and Research on Flow Distribution Unevenness in Intake Manifold for a Turbocharged Diesel Engine
Authors: Yang Shuai , Yan Kai , Liu Haifeng , Fu Yahao , Liu Hairan , Li Tong
Published: April 2024

The design of engine intake system affects the intake uniformity of each cylinder of the engine, which in turn has an important impact on the engine performance, the uniform distribution of EGR exhaust gas and the combustion process of each cylinder. In this paper, the constant-pressure supercharged diesel engine intake pipe is used as the research model to study the intake air flow unevenness of the intake pipe of the supercharged diesel engine. The pressure boundary condition at the outlet of each intake manifold is set as the dynamic pressure change condition. The three-dimensional numerical simulation of the transient flow process in the intake manifold of diesel engine is simulated and analyzed by using numerical method, and the change of the Intake air flow field in the intake manifold under different working conditions during the intake overlapping period is discussed. The dynamic effects of diesel engine intake boost pressure, rotated speed, and intake pipe geometrical characteristic on the air mass flow at the outlet of each intake manifold, intake air distribution quality, and maximum intake unevenness are analyzed. According to numerical calculation result, it was obtained that the main reasons affecting the intake unevenness of each cylinder of diesel engine and the methods to reduce the intake unevenness: The lower the intake boost pressure of diesel engine, the greater the maximum intake unevenness. The greater the intake overlapping angle, the greater the maximum intake unevenness. When the diesel engine was working at low rotated speed, the maximum intake unevenness was higher than that at high rotated speed due to the long intake overlapping time. By increasing the boost pressure of the intake air, the unevenness intake air distribution of the diesel engine during the intake process could be reduced.
Optimization of Cold Start Performance of Diesel Engine Under Low Temperature and High Altitude Environment
Authors: Fang Liang , Chen Boyu , Lou Diming , Xu Kaiwen , Tan Piqiang , Hu Zhiyuan , Zhang Yunhua , Zhen Lei
Published: April 2024

The problem of keeping the stable starting performance of diesel engine under high altitude and low temperature conditions has been done a lot of research in the field of diesel engine, but there is a lack of research on extreme conditions such as above 2000 meters above sea level and below 0°C. Aiming at solving the cold start problem of diesel engine in extreme environment, a set of chamber system of cold start environment diesel engine was constructed to simulate environment of 3000m altitude and -20°C. A series of experimental research was conducted on cold start efficiency optimization strategy of a certain type of diesel engine at 3000m altitude and -20°C. In parallel, a diesel engine model was constructed through Chemkin to explore the influence of the three parameters of compression ratio, stroke length, and fuel injection advance angle on the first cold start cycle of diesel engine at 4000m altitude and -20°C. The simulation results show that in altitude 4000m and -20°C conditions, increasing the compression ratio, stroke length and appropriately reducing the fuel injection advance angle can shorten the ignition delay period of the first cycle of the diesel engine, and improve the peak cylinder pressure and heat release rate peak. Experimental results show that in altitude 3000m and -20°C conditions, increasing compression ratio, stroke length, starting torque, and properly adjusting diesel engine fuel injection advance angle can improve diesel engine cold start performance to various degrees.
Uncertainty Introduced by Image Projection in Video-Based Reconstructions of Vehicle Positions and Speeds
Authors: Young Cole , Flynn Thomas , Miller Ian , Siegmund Gunter P.
Published: April 2024

Video evidence in collision reconstruction has become a common foundation for vehicle position and speed analyses. The goal of this study was to explore how the uncertainty of these position/speed analyses is affected by various camera-, scene-, and vehicle-related properties. To achieve this goal, we quantified how the size and aspect ratio of pixels in the pixel grid change as a result of correcting for lens distortion and projecting the pixel grid onto a real-world surface captured by the image. Relying on both general and case-specific examples, we used Monte Carlo analyses to explore how uncertainty can be calculated and how it varies for different measurements and different camera-, scene-, and vehicle-related properties. We found that i) the aspect ratio of image pixels projected onto a road surface can vary by multiple orders of magnitude over an entire image and generally increases rapidly as the projected pixel nears the horizon; ii) the uncertainty associated with the real-world position of an object in an image depends on the measurement direction in relation to the elongated axis of the projected pixels in the region of interest, and iii) physical kinematic constraints that govern the motion of a vehicle can be used to reduce the uncertainty of a pixel-based analysis in some situations. Overall, these findings show that uncertainty in video-based reconstruction analyses cannot be expressed as a universally applicable percent error; instead, the uncertainty of a measurement depends on the unique combination of camera, scene, and vehicle in a specific analysis.
Occupant Kinematics During Chain-Collisions: Discrete vs Combined Collisions
Authors: Bussone William R. , Koiler Reza , Benda Jamie , Carney Nicholas , Geffard Andres , Sam Samantha
Published: April 2024

There is little prior research into chain-collisions, despite their relatively large contribution to injury and harm in motor-vehicle collisions. This study conducted a series of rear-impact, front-impact, and chain-collision impacts using a bumper car ride at an active amusement park as a proxy for automobiles. The purpose was to begin to identify the threshold time range when separate, discrete collisions transition into a hybrid or combined chain-collision mode and provide bases for future analyses. The test series consisted of rear impacts into an occupied target vehicle from a driven bullet vehicle; frontal impacts into a perimeter barrier (wall); chain-collisions consisting of a driven bullet vehicle striking an occupied primary target vehicle, which then collided with a non-occupied secondary target vehicle; and chain-collisions consisting of a driven bullet vehicle striking an occupied primary target vehicle which then collided with a wall. Time between collisions was adjusted via spacing. Vehicle impact velocities, changes in velocity (delta-Vs), accelerations, and coefficients of restitution are reported. Head and extremity excursions of the restrained occupant of the primary target vehicle were also tracked using high-speed video recording. The results show that chain-collisions exhibited three phases: an early phase that occurs during the initial rearward occupant excursion, a middle phase that occurs during the forward rebound occupant excursion, and a late phase that occurs while the occupant is recovering back to the initial position. The first phase appears to last for approximately 150 ms, the middle phase for approximately 50 to 75 ms, and the late phase from thereafter until approximately 400 ms to 500 ms after the initial collision. The middle phase appears to be related to the timing of the occupant’s return to their original position and their maximum rebound velocity and the late phase to the remaining occupant displacement but not velocity. Overall, occupant and vehicle kinematics during a chain-collision were different from those of the individual component collisions and were different from a superposition of the component collisions. This is the first reporting of these phases in a chain-collision.
Path Planning and Robust Path Tracking Control of an Automated Parallel Parking Maneuver
Authors: Cao Xincheng , Guvenc Levent
Published: April 2024

Driver’s license examinations require the driver to perform either a parallel parking or a similar maneuver as part of the on-road evaluation of the driver’s skills. Self-driving vehicles that are allowed to operate on public roads without a driver should also be able to perform such tasks successfully. With this motivation, the S-shaped maneuverability test of the Ohio driver’s license examination is chosen here for automatic execution by a self-driving vehicle with drive-by-wire capability and longitudinal and lateral controls. The Ohio maneuverability test requires the driver to start within an area enclosed by four pylons and the driver is asked to go to the left of the fifth pylon directly in front of the vehicle in a smooth and continuous manner while ending in a parallel direction to the initial one. The driver is then asked to go backwards to the starting location of the vehicle without stopping the vehicle or hitting the pylons. As a self-driving vehicle should do a much better job repeatably than a driver, a high order polynomial path model is built along with speed profiling to start and stop smoothly at the ends of the path without large longitudinal and lateral accelerations. In contrast to the long horizon, higher speed path planning and path tracking control applications in the literature, this paper treats low speed and very short horizon path planning and path tracking control with stopping and direction reversal. The path is constructed using a segmented polynomial fit optimization routine that guarantees path curvature smoothness. A linear path-tracking model is utilized as the basis of the designed control system consisting of a disturbance observer based curvature rejection filter and a speed-scheduled, parameter-space robust PID controller. Simulation studies are conducted to analyze the tracking performance of the combined control system, and results indicate that it has better performance compared to other common control systems such as standalone PID controller and combined PID and feedforward control.
Effect of Port Water Injection on the Knock and Combustion Characteristics for an Argon Power Cycle Hydrogen Engine
Authors: Tang Yongjian , Deng Jun , Xie Kaien , Jin Shaoye , Li Liguang
Published: April 2024

Argon power cycle hydrogen engine is an internal combustion engine that employs argon instead of nitrogen of air as the working fluid, oxygen as the oxidizer, and hydrogen as the fuel. Since argon has a higher specific heat ratio than air, argon power cycle hydrogen engines have theoretically higher indicated thermal efficiencies according to the Otto cycle efficiency formula. However, argon makes the end mixture more susceptible to spontaneous combustion and thus is accompanied by a stronger knock at a lower compression ratio, thus limiting the improvement of thermal efficiency in engine operation. In order to suppress the limitation of knock on the thermal efficiency, this paper adopts a combination of experimental and simulation methods to investigate the effects of port water injection on the knock suppression and combustion characteristics of an argon power cycle hydrogen engine. The results show that the port water injection can effectively reduce the knock intensity of the argon power cycle hydrogen engine and optimize the combustion process, thus achieving the improvement of the indicated thermal efficiency and the indicated mean effective pressure. A maximum indicated thermal efficiency of 50.8% was achieved in the test at -5 °CA ATDC ignition time and 2ms per cycle water injection pulse width(15.83mg). However, excessive water injection rather deteriorates the combustion process with a loss of indicated thermal efficiency. Further simulation analysis based on the GT-Power model showed that the indicated thermal efficiency was improved to a maximum value 52.4%, when the water injection was reduced to 13 mg and the ignition time was -6 °CA ATDC.
Effect of Timing Strategy on Mixture Formation, Performance and Emission of Inlet Injection Hydrogen Engine
Authors: Hu Zhiyuan , Yin Li , Zhang Yunhua , Lou Diming , Tan Piqiang , Liu Dengcheng
Published: April 2024

In order to scrutinize the timing variables impacting the combustion performance and emissions of the Port Fuel Injection hydrogen engine (PFI-H2ICE), a model of a four-cylinder hydrogen engine is meticulously built utilizing the 1D software GT-POWER. The effect of excess air coefficients and timing strategies (including the intake valve opening timing (IVO), the start of injection timing (SOI), and ignition timing) is analyzed in this study. The main conclusions are as follows: The hydrogen engine remold from the Isuzu JE4N28 nature gas engine manifests a lean combustion threshold ranging between 2.0 and 2.5. Notably, advancing intake valve opening timing by 20°CA has proven beneficial to the brake thermal efficiency (BTE) of the hydrogen engine while reducing the NOx emissions by a substantial margin, and advancing intake valve opening timing bears the virtue of strengthen the positive influence of the start of injection timing upon the engine's combustion performance. The longer the formation duration of the air-fuel mixture from the start of hydrogen injection timing to the ignition timing enables the better the combustion performance of the engine and the lower the NOx emissions. The outside-cylinder mixing time shows a stronger impact on the brake thermal efficiency, whereas the inside-cylinder mixing time has a greater impact on NOx emissions. The influence level of ignition timing, start of injection timing, and intake valve opening timing upon the combustion performance and emissions of the hydrogen engine decreases successively.
Post-Oxidation Phenomena as a Thermal Management Strategy for Automotive After-Treatment Systems: Assessment by Means of 3D-CFD Virtual Developmen
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Authors: Barillari Loris , Pipolo Mario , Della Torre Augusto , Montenegro Gianluca , Onorati Angelo , Vacca Antonino , Chiodi Marco , Kulzer André
Published: April 2024

The target of the upcoming automotive emission regulations is to promote a fast transition to near-zero emission vehicles. As such, the range of ambient and operating conditions tested in the homologation cycles is broadening. In this context, the proposed work aims to thoroughly investigate the potential of post-oxidation phenomena in reducing the light-off time of a conventional three-way catalyst. The study is carried out on a turbocharged four-cylinder gasoline engine by means of experimental and numerical activities. Post oxidation is achieved through the oxidation of unburned fuel in the exhaust line, exploiting a rich combustion and a secondary air injection dedicated strategy. The CFD methodology consists of two different approaches: the former relies on a full-engine mesh, the latter on a detailed analysis of the chemical reactions occurring in the exhaust line. The coupling between experimental data and simulation results provides a complete assessment of the investigated phenomena. After the validation of the numerical methodology for one fixed engine operating point, a specific investigation is performed to assess the benefits of post-oxidation in terms of catalyst light-off time. Finally, the simulation strategy is applied considering a different fuel: hydrogen. Accordingly, both the full-engine mesh simulation and the detailed analysis of the exhaust line are performed. The 3D-CFD virtual development allows a comparison between the results obtained through gasoline and hydrogen, thus highlighting the differences and the possible improvements associated with the application of the alternative fuel and the exploitation of its peculiar features.
A 3-D Computational Fluid Dynamics Modeling of the Churning Loss and Oil Pattern in a Single-Stage Gearbox
Authors: Chen Yawei , Mohapatra Chinmoy K. , Gao Haiyang
Published: April 2024

Modern gearboxes are meticulously engineered with three primary objectives: enhancing load-carrying capacity, minimizing noise, vibration, and harshness (NVH), and optimizing efficiency. Efficiency, in particular, holds paramount significance due to gearboxes’ substantial influence on energy consumption. One effective strategy for boosting efficiency involves curbing churning losses, stemming from the movement of oil within the gearbox housing. Computational fluid dynamics (CFD) techniques have emerged as invaluable tools for visualizing oil flow dynamics within gearboxes and pinpointing avenues for mitigating churning losses. In the context of electric vehicles (EVs), specifically battery electric vehicles (BEVs), extending their driving range is a top priority. Achieving this hinges on the design of an efficient gearbox. This study employs an oil/air multi-phase volume of fluid (VOF) method in a commercial CFD solver known as Simerics-MP+ to model the oil flow and churning losses within a single-stage gearbox. The model’s predictions are validated against previously published highspeed camera footage and measurements derived from the FZG noload power loss test rig’s single-stage gearbox. The simulation results underscore the potential of CFD simulations in providing an exceptionally detailed portrayal of oil flow behavior, while also aligning closely with experimental measurements concerning churning losses. Additionally, two different modeling approaches for gearbox simulations are compared and the advantages are discussed. This study provides engineers with a new tool that can be used to improve the efficiency and reliability of gearboxes in BEVs.
A Review of Battery Thermal Management System for New Energy Vehicles at Subzero Temperatures
Authors: Huang Hai , Tang Xuan , Zhou Youhang
Published: April 2024

The pressure of energy transition and sustainable development has driven the rapid development of new energy vehicles (NEVs). Lithium-ion batteries (LIBs) are extensively utilized in NEVs because of their higher energy density, lower self-discharge rate, and environmental friendliness. Nevertheless, at subzero temperature environments, the electrochemical performance and available energy of LIBs are severely reduced, exhibiting significant charging difficulties, lifespan degradation, and safety issues. This performance degradation can contribute to the operational difficulties and safety hazards of NEVs. The purpose of this article is to provide a review of the challenges and limitations faced by LIBs in subzero temperature environments, as well as the development of subzero temperature LIBs from the cell level to the system level. Additionally, viable solutions to heat the battery by increasing the internal temperature are introduced. This paper provides a systematic review of low-temperature LIBs and offers a reference direction for the subzero-temperature thermal management of LIBs in NEVs.
Modeling Pre-Chamber Assisted Efficient Combustion in an Argon Power Cycle Engine
Authors: Kim Joohan , Scarcelli Riccardo , Beardsell Guillaume , Strickland Tyler , Nilsen Christopher , Sierra Aznar Miguel
Published: April 2024

The Argon Power Cycle (APC) is a novel zero-emission closed-loop argon recirculating engine cycle which has been developed by Noble Thermodynamics Systems, Inc. It provides a significant gain in indicated thermal efficiency of the reciprocating engine by breathing oxygen and argon rather than air. The use of argon, a monatomic gas, greatly increases the specific heat ratio of the working fluid, resulting in a significantly higher ideal Otto cycle efficiency. This technology delivers a substantial improvement in reciprocating engine performance, maximizing the energy conversion of fuel into useful work. Combined Heat and Power (CHP) operating under the APC represents a promising solution to realize a net-zero-carbon future, providing the thermal energy that hard-to-electrify manufacturing processes need while at the same time delivering clean, dispatchable, and efficient power.

Since the working fluid in an APC is synthetic, the concentration of argon, oxygen, fuel, and carbon dioxide (if combusting a carbon-based fuel) can be precisely adjusted for optimal performance across a wide range of loads. At low load, the in-cylinder mixture is highly diluted, which can present challenges in terms of achieving sufficient flame speed and therefore efficient and reliable combustion. Pre-chamber (PC) combustion has the potential to accelerate the combustion rate by creating multiple turbulent hot jets that provide spatially distributed ignition sources with enhanced turbulent mixing. PC combustion can also help reduce the tendency for knock because it promotes more uniform and timely combustion of the fuel-air mixture in the main-chamber. Computational fluid dynamics (CFD) simulations can assist in the optimization of PC design and operating strategy, but CFD models have not yet been validated against experimental data for the challenging conditions encountered in highly diluted APC engines. This study presents 3D CFD modeling for a natural gas, pre-chamber spark-ignition engine used in an APC. A skeletal mechanism for natural gas combustion in an oxygen-argon mixture is employed, and a level-set based G-equation model is used to simulate the combustion process. Simulations are performed under the Reynolds-Averaged Navier-Stokes framework, and the results are compared to experimental engine data in terms of cylinder pressure, apparent heat release, and mass fraction burned timing. The validated model is also used to investigate different oxidizer compositions and their impact on the indicated thermal efficiency.
Research on the Oscillation Reduction Control During Mode Transition in Hybrid Electric Vehicles
Authors: Jing Junchao , Zhang Junzhi , Liu Yiqiang , Huang Weishan , Dai Zhengxing
Published: April 2024

In order to realize the series-parallel switching control of hybrid electric vehicle (HEV) with dual-motor hybrid configuration, a method of unpowered interrupt switching based on the coordinated control of three power sources was proposed by analyzing the series-parallel driving mode of the dual-motor hybrid configuration. The series to parallel switching process is divided into three stages: speed regulation stage, clutch combination and power source switching. The distribution control of speed regulating torque is carried out in the speed regulating stage. The speed adjustment torque is preferentially allocated to the power source of the input shaft (engine and P1) to carry out the lifting torque. Due to the high speed adjustment accuracy and fast response of the P1 motor, the input shaft is preferentially allocated to P1 for speed adjustment, that is, the torque intervention of P1. If the speed control torque exceeds the intervention capacity of P1, then it is allocated to the engine for speed regulation. In the clutch combination stage, by identifying the motor speed change in the oil filling stage and the shifting stage, the current mode switching under test and the oil filling effect of the shifting clutch are evaluated, and the current mode switching under test and the KP point state of the shifting clutch are judged. Due to the differences in different transmission processing and assembly processes, as well as the wear of the clutch in the whole life cycle; The friction coefficient of the clutch is not a fixed value, so it is necessary to develop the automatic adjustment function for the friction coefficient of the clutch. The friction coefficient of clutch reflects the relationship between clutch torque and pressure, and plays an important role in controlling clutch torque precision. The switching process from parallel mode to series mode is divided into three stages: power source switching, clutch opening and engine operating point shifting. The control method is verified by simulation analysis and real vehicle test. The results show that no power interruption occurs during the whole switching process. Therefore, the control method can successfully complete the series-parallel switching control.
A Study on the CFD-guided Gas Flow Field Plate Optimization of a PEM Fuel Cell with Wave Flow Channels
Authors: Chen Ceyuan , Wei Jingsi , Zhan Wenfeng , Xu Hanjun , Zhang Pengfei , Lin Qianyu
Published: April 2024

The gas flow field design of proton exchange membrane (PEM) fuel cells is crucial to achieve high and stable performance. Since the mass transfer process of air is much more difficult than that of hydrogen, and the possible occurrence of flooding could make performance deteriorate rapidly, the gas flow in the cathode plate is especially important. In the present study, three-dimensional (3D) computational fluid dynamics (CFD) simulations were conducted to evaluate and optimize the performance of a baseline flow field pattern, which is characterized by wave flow channels. The active area is up to the same order as that of commercial products. To consider the turbulent flow, the Reynolds-averaged Navier-Stokes (RANS) approach coupled with the standard k-ω model was used. Moreover, a blend of the viscous and log-law solutions was implemented to calculate the specific dissipation rate in grids near the wall. A flexible grid control method, adaptive mesh refinement (AMR), consisting of both boundary AMR and sub-grid scale (SGS) AMR was also adopted to accelerate simulations while maintaining good accuracy. To validate numerical models, the total pressure losses which were calculated from simulations and obtained from measured data under different boundary conditions have been compared. Results showed that simulations matched well with experimental data. Furthermore, the effect of flow field changes in distribution and reaction zones on both the flow uniformity and pressure loss was investigated. Finally, a methodology to quickly estimate the pressure losses with different channel depths was demonstrated. The correlation analysis results showed that the overall pressure drop has an obvious linear correlation with the inverse square of channel depth.
Research on the Power-on and Power-Off Control and Propulsion Control Method in Hybrid and Electric Vehicles
Authors: Jing Junchao , Liu Yiqiang , Zhong Yongchang , Huang Weishan , Dai Zhengxing
Published: April 2024

The traditional car's power-up and power-down sequence is only designed for 12V low-voltage system, which is harmless to human body and does not involve the functional safety of the vehicle. The existing power-up and power-down technologies for high-voltage systems (above 220V) are mostly designed for pure electric vehicles, plug-in hybrid electric vehicle, and non-plug-in hybrid electric vehicle. There is no one process that is applicable to EV, PHEV, and HEV, and it rarely involves the power-up and power-down sequence of one-key start and remote start, and for the power-down delay problem when there is battery cooling and motor cooling request, the battery failure, DCDC failure, collision, low battery SOC, the active power-down sequence problem when the external charging gun is connected, and the sequence problem when the controller resets the fault. The seven states of the power-up and power-down sequence control defined in this paper are: state 1 is the initial state, state 2 is the CPSR relay disconnection, state 3: the CPSR relay is closed, state 4: the high-voltage relay is closed, state 5: the DCDC is closed, state 6: the initial state of the collision, and state 7: the collision state. Compared with other technologies, the timing definition of the collision state is added. The control logic modeling and simulation analysis of the vehicle's power-up, power-down and motor management system faults are conducted by Simulink, and the verification is carried out under the real vehicle test. The test results show that the power on and the power off treatment accord with the control logic, the failure power off treatment ensures the high voltage safety, and the power on and off control logic is more conducive to the vehicle energy control.
Open-loop Torque Control Strategy based on Constant Volume Instantaneous Combustion Model
Authors: Kang Jun-Mo
Published: April 2024

A model-based torque control strategy which is simple and easily adaptable to various types of engines is developed in this paper. A torque model is derived from constant-volume combustion model, and applications of the model to engine torque control problem are also discussed. As examples, the torque model is calibrated with experimental data collected from two different engines, and simulation and experimental results from the torque control strategy are presented as well.
4D Radar-Inertial SLAM based on Factor Graph Optimization
Authors: Zihang He , Xiong Lu , Zhuo Guirong , GAO Letian , Lu Shouyi , Zhu Jiaqi , Leng Bo
Published: April 2024

SLAM (Simultaneous Localization and Mapping) plays a key role in autonomous driving. Recently, 4D Radar has attracted widespread attention because it breaks through the limitations of 3D millimeter wave radar and can simultaneously detect the distance, velocity, horizontal azimuth and elevation azimuth of the target with high resolution. However, there are few studies on 4D Radar in SLAM. In this paper, RI-FGO, a 4D Radar-Inertial SLAM method based on Factor Graph Optimization, is proposed. The RANSAC (Random Sample Consensus) method is used to eliminate the dynamic obstacle points from a single scan, and the ego-motion velocity is estimated from the static point cloud. A 4D Radar velocity factor is constructed in GTSAM to receive the estimated velocity in a single scan as a measurement and directly integrated into the factor graph. The 4D Radar point clouds of consecutive frames are matched as the odometry factor. A modified scan context method, which is more suitable for 4D Radar’s sparse and noisy point clouds and field of view, is proposed to detect possible loops. Different from the common front-end odometry and back-end optimization structure, we implement the whole SLAM system including odometry, loop detection and graph optimization in the factor graph. We compared our method with some mainstream methods such as EKFRIO on our own and public datasets. At the same time, ablation experiments were also carried out to illustrate the role of 4D Radar velocity factor and odometry factor. Experiments have shown that our proposed SLAM method can converge the bias of accelerometers and gyroscopes well and has excellent accuracy.
Reduced Order Modeling Technology with AI for Model-Based-Development
Authors: Inagaki Takahiro , Nasu Tadaaki , Takeshige Minoru , Iwata Motofumi , Nakane Naoto
Published: April 2024

This paper introduces reduced-order modeling techniques with Artificial Intelligence (AI) for Model-Based Development (MBD). In vehicle development, detailed physical models are replaced by reduced-order models (ROM) to expedite simulations. With recent advancements in AI-based reduced-order modeling, it is expected that modeling work will become more efficient, leading to reduced simulation times. However, the range of simulations (Model-in-the-Loop Simulation - MILS, Hardware-in-the-Loop Simulation - HILS, bench-system) compatible with ROM is limited. To overcome this limitation, this study leverages the ONNX format (Open Neural Network Exchange), a universally supported format among machine learning frameworks, and the Functional Mock-up Interface (FMI), a standard interface format for simulation tools, to enable general-purpose embedded technology with ROM.

This study employs a vehicle model in engine surge simulations to validate AI-based reduced-order modeling for MBD. In MILS simulations, the ONNX-format model, trained using Long Short-Term Memory (LSTM), is integrated into an FMI-format model compatible with the simulation environment. This FMI-format model is then incorporated into MILS/HILS/bench systems, confirming its capability for accurate simulations. Thus, we have successfully established AI-based reduced-order modeling technology for comprehensive MBD.
Design and Evaluation of an in-Plane Shear Test for Fracture Characterization of High Ductility Metals
Authors: Pilozo-Hibbit Lucas , Narayanan Advaith , Abedini Armin , Butcher Cliff
Published: April 2024

Fracture characterization of automotive metals under simple shear deformation is critical for the calibration of advanced fracture models employed in forming and crash simulations. In-plane shear fracture tests of high ductility materials have proved challenging since the sample edge fails first in uniaxial tension before the fracture limit in shear is reached at the center of the gage region. Although through-thickness machining is undesirable, it appears required to promote higher strains within the shear zone. The present study seeks to adapt existing in-plane shear geometries, which have otherwise been successful for many automotive materials, to have a local shear zone with a reduced thickness. It is demonstrated that a novel shear zone with a pocket resembling a “peanut” can promote shear fracture within the shear zone while reducing the risk for edge fracture. An emphasis was placed upon machinability and surface quality for the design of the pocket in the shear zone. A mild steel and two high strength aluminum alloys were tested using both conventional and modified shear geometries with digital image correlation techniques utilized for strain measurement. The modified geometry increased the equivalent fracture strains of the low and medium ductility aluminum alloys by a respective 24% and 41% relative to the conventional geometry. For the mild steel, the conventional shear geometry failed prematurely at the edges. Edge failure still occurred in the modified geometry but achieved an equivalent strain magnitude of over 300% which is a 62% increase relative to the conventional geometry.
Using Natural Refrigerants Propane (R290) & Carbon Dioxide (R744) as Direct & or Indirect Heat Pump Systems to Address PFAS Issue
Authors: Mathur Gursaran
Published: April 2024

Per - and polyfluoroalkyl substances – known as PFAS are man-made chemicals that do not occur naturally. PFAS are widely used, long lasting chemicals, components of which break down very slowly over time. Scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals. Because of their widespread use and their persistence in the environment, many PFAS are found in human and animals’ blood all over the world and are present at low levels in a variety of food products and in the environment. PFAS are found in water, air, fish, and soil at locations across the nation and the globe.

Both refrigerants (HFC-134a & HFO-1234yf) that are currently used in mobile air conditioning systems (MACS) create PFAS. Hence, various countries are looking into banning chemicals that create PFAS. Natural refrigerants are being proposed as alternative refrigerants as they do not create PFAS. Hence, Propane (R290) and Carbon-Dioxide (R744) are being considered as alternate refrigerants for mobile HVAC systems for internal combustion engine (ICE) vehicles and for electric vehicles (EVs). However, propane is highly flammable, and carbon-dioxide operates at extremely high pressures that needs to be addressed.

In this paper, the author has presented the following details: (i) Current situation of PFAS that the world is facing by providing details of actions by European countries, US and Japan. (ii) Details of the alternate refrigerants including thermodynamic and thermophysical properties comparison that affects heat transfer coefficients and pressure gradients during single and two-phase fluid flow. (iii) Safety Considerations. (iv) Details of the test that the author has conducted with hydrocarbon refrigerants and with carbon-dioxide. (v) Finally, the details with heat pump system architectures are presented using natural refrigerants as direct expansion and indirect systems from a safety and performance perspective for ICE and EVs. It should be noted that currently many OEMs and suppliers have heat pumps systems with high degree of complexity and there is no common standard architecture for the ICE/EV heat pumps system.
Internet of Autonomous Vehicles for The Distribution System of Smart Cities
Authors: Ma Shizi , Wang Sheng , Ma Zhitao , QI Zhiguo
Published: April 2024

With the development of internet technology and autonomous vehicles (AVs), the multimodal transportation and distribution model based on AVs will be a typical application paradigm in the smart city scenario. Before AVs carry out logistics distribution, it is necessary to plan a reasonable distribution path based on each customer point, and this is also known as Vehicle Routing Problem (VRP). Unlike traditional VRP, the urban logistics distribution process based on multimodal transportation mode will use a set of different types of AVs, mainly including autonomous ground vehicles and unmanned aerial vehicles (UAVs). It is worth pointing out that there is currently no research on combining the planning of AVs distribution paths with the trajectory planning of UAVs. To address this issue, this article establishes a bilevel programming model. The upper-level model aims to plan the optimal delivery plan for AVs, while the lower-level model aims to plan a driving trajectory for UAVs. Furthermore, this paper proposes an improved heuristic algorithm for the bilevel programming model. Due to the tendency of Group Search Optimizer (GSO) algorithm to fall into local optima during the process of solving large-scale complex problems, this paper designs an improved GSO algorithm based on improved strategies such as spiral search strategy. During the solving process, based on the upper-level model and using the IGSO algorithm, the distribution order of AVs can be directly solved. In the process of trajectory planning based on the lower-level model, the RRT algorithm is first used to plan an initial trajectory for the UAV. Furthermore, the IGSO algorithm is used to further optimize this trajectory, ultimately achieving the delivery task of the UAV. Finally, a simulation experiment was conducted to compare the effectiveness of the proposed scheme with other algorithms.
An Evaluation of the Performance of the Bendix Wingman Fusion G1 Collision Mitigation System in a 2017 Kenworth T680
Authors: Harrington Shawn , Martin Nicholas , Leiss Peter
Published: April 2024

The Bendix Wingman Fusion – a radar and camera collision mitigation system (CMS) available on commercial vehicles – was evaluated in two separate test series to determine its performance in simulated rear collision scenarios. In the first series of tests, evaluations were conducted in daytime, nighttime, and rainy conditions between 15 to 58 miles per hour (mph) to evaluate the performance of the audible and visual forward collision warning (FCW) system in a first-generation Bendix Wingman Fusion CMS while approaching a stationary live vehicle target (SLVT) in a 2017 Kenworth T680. A second test series was conducted with a 2017 Kenworth T680 traveling at 50 mph in daytime conditions approaching a decelerating vehicle to evaluate the Bendix Wingman Fusion CMS on the truck. Both test series sought to determine the maximum distance the system would warn prior to the test driver swerving around the SLVT or moving vehicle target. The first test series utilized a 2014 Ford F150 as the SLVT and the second test series utilized a 2014 Lexus RX350 as a Decelerating Vehicle Target. Testing measured the time to collision (TTC) values of the issuance of the audible/visual FCW utilizing VBOX data acquisition equipment. The results of the two series of tests provide valuable information about the performance of the Bendix Wingman Fusion CMS approaching stationary and decelerating vehicles in rear collision scenarios.
Analysis of Low-Frequency Brake Noise for Drum Brakes on Semi-Trailers
Authors: Tang Hao , Shangguan Wen-Bin , Kang Yingzi , Zheng Jing-Yuan , Lan Wen-Biao
Published: April 2024

A road test on semi-trailers is carried out, and accelerations of some characteristic points on the braking system,axles,and truck body is measured,also brake pressure and noise around the support frame is acquired.The measured data was analyzed to determine the causes of the brake noise, and the mechanism of the noise of the drum brake of semi-trailers during low-speed braking was investigated. The following conclusions are obtained: (1) Brake noise of the drum brake of the semi-trailer at low-frequency is generated from vibrations of the brake shoes, axle, and body, and the vibration frequency is close to 2nd natural frequency of the axle. (2) Brake noise is generated from stick-slip motion between the brake shoes and the brake drum, where the relative motion between the brake drum and the brake shoes is changed alternately with sliding and sticking, resulting in sudden changes in acceleration and shock vibration. A multi-body dynamic model of the semi-trailer is established for analyzing vibrations causing noise and the influencing parameters. In the model, the elastic deformation of components, such as brake drums, brake shoes, axles, and leaf springs during the braking process, is considered. The model is validated by comparing calculated data with experiment data.The simulation shows that there is a heavy stick-slip vibration between the brake drum and brake shoes, which is transmitted to the axle through the brake shoes, and then to the body through the leaf spring. As the speed of the semi-trailer increases, the stick-slip frequency between the frictional pairs increases. When the stick-slip frequency is close to the natural frequency of the axle, it resonance.
El carácter revisor de la jurisdicción contencioso administrativa en materia tributaria: Las doctrinas del tiro
Authors: Pontón Aricha Teresa
Published: April 2024

SUMARIO: I. Exposición del problema. II. ¿Mera revisión del acto administrativo o plena jurisdicción?. III. La ejecución de la resolución o la pieza que falla. IV. La posición de la Administración Tributaria tras la resolución judicial. V. Conclusiones. VI. Referencias.