bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Shift Control of Dual Clutch Transmission in Electric Vehicles Based on Linear Quadratic Regulator
Authors: Zhou ShuiTing , Wu Jinglai , Zhang Yunqing
Published: April 2023

Unsuitable shift control strategies may increase the vehicle jerk and clutch wear. In order to improve the shift quality of electric vehicles (EVs) equipped with dual clutch transmission, this paper proposes an optimal shift control strategy based on linear quadratic regulator, in which weighting matrices are selected by using genetic algorithm (GA). The dynamics of the shift process of the dual clutch transmission is analyzed to establish the dynamic model of the driving system. In addition to the vehicle jerk, the friction work of clutch is also considered as one of the performance criteria and a new linear quadratic objective function is formulated. The optimal weighting matrices for obtaining a globally optimal solution are selected benefit from the global search capacity of genetic algorithm. The optimal target trajectories of the torque of the two clutches and motor are obtained by simulating the linear quadratic regulator (LQR). The dynamic model of the driving system including dry clutch is built and a controller is introduced to track the optimal target trajectories. The simulation results indicate that the optimal control strategy proposed in this paper can effectively reduce the vehicle jerk and friction work of clutch.
A Novel Position and Posture Measuring Method in the Docking of the Towbarless Towing Vehicle and the Aircraft
Authors: Zhu Hengjia , Chao Wang , Liu Yunhao , Zhang Wei
Published: April 2023

Nowadays the ultrasonic radar, infrared detection, laser scanning radar or other perception technologies have been widely used in the automatic docking conditions. However, it’s not absolutely applicable in severe weather such as heavy rain and snow days, especially in the operation not allowed to fail, for example, the docking of the future unmanned towbarless towing vehicle (TLTV) with the expensive civil plane. A novel mechanism is proposed for relatively position and posture measuring between the TLTV and the aircraft nose tire during the automatic docking operation. The geometrical relationship between the towing vehicle and the nose tire is obtained by mathematical calculation. The position and posture of the nose tire have been obtained by splice angles and the length of rotatable rods connected with the vehicle during the docking operation.
Neural Network Model to Predict the Thermal Operating Point of an Electric Vehicle
Authors: Kolachalama Srikanth , Malik Hafiz
Published: April 2023

The automotive industry widely accepted the launch of electric vehicles in the global market, resulting in the emergence of many new areas, including battery health, inverter design, and motor dynamics. Maintaining the desired thermal stress is required to achieve augmented performance along with the optimal design of these components. The HVAC system controls the coolant and refrigerant fluid pressures to maintain the temperatures of [Battery, Inverter, Motor] in a definite range. However, identifying the prominent factors affecting the thermal stress of electric vehicle components and their effect on temperature variation was not investigated in real-time. Therefore, this article defines the vector electric vehicle thermal operating point (EVTHOP) as the first step with three elements [instantaneous battery temperature, instantaneous inverter temperature, instantaneous stator temperature]. As a next step, a novel deep learning model was proposed utilizing the integrated functions of MATLAB, which predicts the vector EVTHOP mapping the elements of [Body module, Driver behavior, Environmental factors], which represent the dynamic state of the system. The trained models were developed using real-time data retrieved by driving the test vehicle 2023 Cadillac Lyriq, provided by General Motors Inc. Since the data retrieved is time-series, the trained functions were developed using the known established method NARX. The Error vector was defined by estimating the conformance of actual and predicted values. The performance of NARX was done by analyzing the Error using the known statistical techniques (RMSE, Area under the curve, Smoothness measure: RSquare). The data snippets for 100 seconds were selected randomly to validate the deep learning model, and it was observed that statistical analysis of the Error resulted [RMSE < 0.2; Area < 632, RSquare > 0.7] in all scenarios. Thus, the developed predictive model was assumed to produce satisfactory results in predicting the vector EVTHOP.
Study of Flashing Flows Entering Evacuated Sampling Cylinders for Oil Circulation Rate Measurement in an Automotive Air Conditioning System
Authors: Haider Syed Angkan , Wang Xin , Elbel Stefan
Published: April 2023

The oil circulation rate (OCR) is a deciding factor for the performance of automotive air conditioning systems at both the system and component levels. OCR is defined as the percentage by mass of oil present in a representative sample of oil-refrigerant mixture drawn from the system at steady state. In recent years, many industries are opting for low-OCR compressors, and so the OCR values are getting smaller, making it even more important to be able to accurately measure the OCR in the system. All the different OCR measurement techniques rely on the ASHRAE Standard 41.4 for proper calibration. This standard describes OCR measurement using a sampling technique which involves connecting an evacuated sampling cylinder at the liquid line of the system at steady state to draw a sample containing the liquid mixture of refrigerant and oil. However, several factors such as orientation of sampling cylinder and valve opening speed can affect the OCR results. The flow entering the sampling cylinder initially consists of both liquid refrigerant and liquid oil. As the valve on the sampling cylinder is opened, the refrigerant undergoes flashing followed by recompression and re-condensation of vapor refrigerant, and simultaneous filling up with liquid mixture until pressure equalization between the system supply line and evacuated sampling cylinder is achieved. This two-phase, two-component, phase changing flow is complex, and for the present study, flow visualization using a high-speed camera and analytical tools are used to study the flashing flow of pure refrigerant entering an evacuated sampling cylinder. The obtained results are used to compare with those obtained with oil-refrigerant mixture to shed light on how parameters such as sampling cylinder orientation and valve opening speed can affect the measured OCR values.
Transient Oil Migration and Flow Behavior during Automotive Compressor Startup
Authors: Wang Xin , Haider Syed Angkan , Elbel Stefan
Published: April 2023

Oil migration has a great impact on vapor compression systems, especially for automobile air conditioning systems which require frequent on-off cycling without sufficient oil management inside the compressor. Excessive amounts of oil retained in the system and lack of oil returned to the compressor can cause low system efficiency and potential compressor failure. This paper explores and quantifies the transient effects in oil migration and property changes at the compressor suction and the discharge. Oil flow behavior and oil migration are quantified and analyzed by the high-speed camera recording and optical method at the compressor discharge and the liquid line under different compressor startup speeds and on-off frequencies. The flow under cold and warm startup conditions is studied and compared. The oil-refrigerant mixture flow at the suction and discharge during cold startup transitions from two-phase flow to vapor refrigerant flow and oil annular mist flow. Severe oil foaming happens inside the compressor and at the discharge. Plug flow, foam flow, bubbly flow and annular mist flow were observed within three minutes after compressor cold startup before steady state is reached. In contrast, after a short idle time, the oil flow develops to annular mist flow in steady state within one minute without foam happening and phase transition. The difference between oil flow behaviors is explained by mixture property variations such as oil-refrigerant solubility, viscosity, and saturation pressure. The characterization helps to reduce oil migration and improves further oil management strategies of the system.
Driver Mental Stress in Response to Thermal Stress Change during Highway Driving
Authors: Song Donghyun , Kim Eunjee , Kwon Yujin , Yoon Woojin , Lee Baekhee , Lee Yoseob , Shin Gwanseob
Published: April 2023

Monitoring driver thermal stress is an integral step for developing an automated climate control function. In this experimental study, various physiological measures for driver’s thermal stress were tracked while intentionally by altering thermal conditions of the seat with a seat air conditioning system (ACS) in summer and a seat heating system (HS) in winter. It was aimed to determine reliable physiological measures for identifying the changes in thermal status induced by the two seat climate control systems. In the first experiment, twenty experienced drivers drove a comfortable sedan for 60 minutes on a real highway while varying the intensity of the seat ACS every 10 minutes to incur ‘hot’ – ‘cool’ – ‘hot’ – ‘cool’ thermal stress. In the second experiment, a new group of eighteen drivers drove the same highway for 30 minutes while increasing the intensity of seat HS to incur ‘cold’ to ‘warm’ thermal stress. Their thermal stress status has been evaluated by heart rate variability (HRV), skin conductance (SC) level, heart rate (HR), and respiration (RES) rate, as well as subjective discomfort ratings during driving. The reliability of each physiological measure was determined by detection rate, which indicated the ratio of occurrences that the physiological measure followed the changes in thermal conditions. The thermal change by seat ACS was detected over 60% by the high-frequency power of HRV, mean SC level, and RES rate. Changes in the thermal stress by seat HS were detected over 60% by the low-frequency power of HRV and RES rate. The findings of this study suggest that monitoring the driver’s HRV and RES rate may enable the vehicle to detect the changes in the driver’s thermal stress reliably.
Hierarchical Decentralized Model Predictive Control for Multi-Stack Fuel Cell Vehicles Using Driving Cycle Data
Authors: Khalatbarisoltani Arash , Hu Xiaosong
Published: April 2023

The energy management strategy, commonly known as the EMS, is an essential component of fuel cell cars (FCVs). The majority of current research is concentrated on centralized emergency management systems (Cen-EMSs), but it does not provide sufficient flexibility (plug-and-play) or robustness. Regarding this matter, a hierarchical decentralized energy management system (Dec-EMS) that is based on a model predictive control (MPC) technique is offered for a modular FCV powertrain that is comprised of two parallel proton exchange membrane fuel cells (PEMFC) and an energy storage system. Gain scheduling makes the proposed Dec-EMS controller more effective in terms of its performance. The hierarchical decentralized control approach is assessed within the framework of a driving scenario that is representative of real-world conditions. According to the numerical result, the decentralized emergency management system (Dec-EMS) proposal provides superior performance than the centralized approach.
Demonstration of Ego Vehicle and System Level Benefits of Eco-Driving on Chassis Dynamometer
Authors: Bhagdikar Piyush , Sarlashkar Jayant , Gankov Stanislav , Rengarajan Sankar
Published: April 2023

Eco-Driving with connected and automated vehicles has shown potential to reduce energy consumption of an individual (i.e., ego) vehicle by up to 15%. In a project funded by ARPA-E, a team led by Southwest Research Institute demonstrated an 8-12% reduction in energy consumption on a 2017 Prius Prime. This was demonstrated in simulation as well as chassis dynamometer testing. The authors presented a simulation study that demonstrated corridor-level energy consumption improvements by about 15%. This study was performed by modeling a six-kilometer-long urban corridor in Columbus, Ohio for traffic simulations. Five powertrain models consisting of two battery electric vehicles (BEVs), a hybrid electric vehicle (HEV), and two internal combustion engine (ICE) powered vehicles were developed. The design of experiment consisted of sweeps for various levels of traffic, penetration of smart vehicles, penetration of technology, and powertrain electrification. The large-scale simulation study consisted of doing approximately 96,000 powertrain simulations. A sophisticated clustering scheme was built and utilized to down select representative traces for each scenario from the simulation study for vehicle testing on a chassis dynamometer. This paper provides a summary of individual ego vehicle testing as well as a comprehensive overview of the method utilized for down selecting representative traces from large scale simulation studies that can be used to quantify corridor level benefits. Vehicle test results along with corresponding analyses are presented.
Predicting Lead Vehicle Velocity for Eco-Driving in the Absence of V2V Information
Authors: LAKSHMANAN Vinith Kumar , Gupta Shobhit , D'Alessandro Stefano , Spano Matteo , Kibalama Dennis , Stockar Stephanie , Canova Marcello , El Ganaoui-Mourlan Ouafae , Sciarretta Antonio
Published: April 2023

Accurately predicting the future behavior of the surrounding traffic, especially the velocity of the lead vehicle is important for optimizing the energy consumption and improve the safety of Connected and Automated Vehicles (CAVs). Several studies report methods to predict short-to-mid-length lead vehicle velocity using stochastic models or other data-driven techniques, which require availability of extensive data and/or Vehicle-to-Vehicle (V2V) communication. In the absence of connectivity, or in data-restricted cases, the prediction must rely only on the measured position and relative velocity of the lead vehicle at the current time. This paper proposes two velocity predictors to predict short-to-mid-length lead vehicle velocity. The first predictor is based on a Constant Acceleration (CA) with an augmented stop mode. The second one is based on a modified Enhanced Driver Model (EDM-LOS) with line-of-sight feature. Both predictors rely only on information on the present values of lead vehicle position and velocity to compute a future velocity estimate. An analysis is done to compare the prediction accuracy of the proposed predictors with different experimental driving data recorded using an OBD2 scanner plugged into a passenger vehicle. Finally, the predicted lead vehicle velocity is utilized to formulate time-gap constraints for the eco-driving optimal control problem, solved via Model Predictive Control (MPC). The energy savings of the considered velocity predictors are evaluated by performing a large-scale simulation study. The proposed velocity predictor provides closest energy savings to a wait-and-see solution for a CAV in absence of V2V communication.
Investigation of High Fuel Pressure and Multiple Injection to Reduce Engine Emission during Catalyst Light-Off
Authors: Lonari Yashodeep , Yoneya Naoki , Miyake Takao , Namaizawa Yasuo
Published: April 2023

The demand for clean energy efficient transportation is rapidly increasing to meet greenhouse gas emissions reduction and promote sustainability. Gasoline direct injection engines (GDI) have high thermal efficiency thus low greenhouse gas emissions compared with conventional port fueled engines. However, during cold start conditions GDI engines produce harmful emissions, including nitrogen oxides, hydrocarbons, and particulate matter. Thus, high pressure fuel system development for direct injection of gasoline is being conducted to reduce emissions during engine cold start. This paper summarized the effect of high fuel pressure and multiple injections on cold catalyst light-off strategy for rapid heating of the catalyst. Experiments were carried out using light-duty four-cylinder engine at cold catalyst light-off conditions with coolant temperature at 30 °C. Fuel injection strategy optimization was carried out considering (a) 25 MPa - two injections (b) 25 MPa - three injections and (c) 35 MPa - three injections, and engine emission, combustion stability, as well as fuel consumption data analyzed for each case. Experimental results show that 25 MPa and 35 MPa fuel injection pressure with three injection pulse have 60% and 80% reduction of HC and NOx combined relative to 25MPa fuel injection pressure and two injection pulse. It is expected that the improved homogeneous mixing realized by controlling spray penetration with multiple injections as well as the better spray atomization due to high fuel pressure, led to further HC reductions in the presence of high internal residual gases. Moreover, it has been also found that the combustion stability, and fuel consumption were similar for all three cases considered in this study. Experimental results show the benefits of using high pressure fuel injector with multiple injection strategies to realize reductions in engine emissions.
A Computational Investigation of Piston Bowl Geometry Effects on PPCI-Diffusion Combustion in a Light-Duty GCI Engine
Authors: Zhang Yu , Zhang Anqi , Sellnau Mark
Published: April 2023

A PPCI-diffusion combustion strategy has shown the potential to achieve high efficiency, clean gasoline compression ignition (GCI) combustion across the full engine operating range. By conducting a 3-D CFD-led combustion system design campaign, this investigation was focused on developing a next generation (NextGen), step-lipped piston design concept in a 2.6L advanced light-duty GCI engine. Key geometric features of the NextGen piston bowl were parametrized and studied with customized spray targeting. A low lip positioning design with 128° spray targeting was found to provide the best performance.

Fuel injection strategy optimization was performed at a full-load operating point (OP), 2000 rpm/24 bar closed-cycle IMEP (IMEPcc). When combined with the optimized fuel injection strategy, the best NextGen design was predicted to produce a 1.3% ISFC improvement and 42.5% lower soot compared to the baseline piston bowl design due to faster diffusion combustion and enhanced late-stage air-utilization. Subsequently, at 2000 rpm/12 bar IMEPcc, the NextGen design was able to soften the first-stage PPCI combustion to reduce the negative work and lower the MPRR, leading to 2.1% better ISFC and 48.8% lower soot than the baseline design when combined with its benefit to improve the second-stage diffusion combustion. Finally, at 1500 rpm/6 bar IMEPcc, the NextGen design was found to appreciably reduce the in-cylinder heat transfer and enable a larger fuel injection quantity in the first fuel injection event while retaining its air utilization benefit compared to the baseline design. Therefore, it was predicted to produce 2.4% better ISFC and 49.3% lower soot.
Underexpanded Impinging Gaseous Jet Interaction with a Lubricated Cylinder Surface
Authors: Ben David Holtzer Ben Binyamin , Tartakovsky Leonid
Published: April 2023

The dynamics of the gaseous jet is a major factor affecting the particulate matter and gaseous pollutants formation in the combustion of hydrogen or a hydrogen-rich reformate. Mitigation of particulate matter formation is essential for the sustainability of a novel high-efficiency propulsion cycle with High-Pressure Thermochemical Recuperation which has been developing in the Technion. The latter suffers from elevated particle emissions compared to hydrocarbon fuels combustion in a wide range of operating regimes. An intensified lubricant involvement in the combustion process was found to be the source of the elevated particle formation in a non-premixed reformate and hydrogen combustion. The reported research further analyzes and compares using analytical, empirical, and experimental tools the gaseous impinging underexpanded jet evolution and propagation with a focus on the lubricant vapor entrainment mechanisms from a heated cylinder wall surface into the combustion chamber bulk. Shadowgraph optical imaging was employed to investigate the impinging jet interaction with a heated lubricated surface. Semi-analytical model of the jet development along the piston axis and the cylinder wall after impingement has been derived and validated based on previous publications and the experimental results of this study. The obtained experimental data showed for the first time that the evolving after impingement gaseous fuel vortex climbs over the liner wall and sweeps away the lubricant vapors into the combustion chamber bulk. This entrainment mechanism was found to be stronger compared with the lubricant entrainment in the free-jet region. The lower heating value of the reformate fuel compared to hydrogen requires a longer injection duration and/or higher injection pressure. These contribute to longer and more intensive vortex flow along the cylinder wall, thus explaining the previously observed higher particle formation with the reformate compared to hydrogen. Fundamental principles of the impinging jet interaction with a heated lubricated surface have been discussed. Possible ways of mitigating the lubricant vapor entrainment into the combustion bulk have been suggested.
Layer Coating on DPF for PN Emission Control
Authors: Zhao Chuang , Wang Lifeng , Lou Diming , Ren Yedi
Published: April 2023

China VI emission standards (Limits and measurement methods for emissions from diesel fueled heavy-duty vehicles, China VI, GB17691-2018) have strict particle number (PN) emission standards and so the coated diesel particulate filter (DPF) technology from the EU and US market has challenge in meeting the regulation. Hence, a coated DPF with higher PN filtration efficiency (FE) is required. Currently, there are two approaches. One is from the DPF substrate standpoint by using small pore size DPF substrate. The other is from the coating side to develop a novel coating technology. Through the second approach, a layer coating process has been developed. The coated DPF has an on-wall catalytic layer from inlet side and an in-wall catalytic coating from outlet side. The DPF has improved PN filtration efficiency and can meet China VI regulation without any pre-treatment. It has lowered soot loading back pressure (SLBP), compared to the DPF with small pore size. The paper will discuss the design concept, the impact of key parameters and some application cases.
Development of New V6 3.0 L Turbocharged and 3.5 L Naturally Aspirated Gasoline Direct Injection Engines
Authors: Taki Shotaro , Konishi Yukio , Tomitani Yuki , Ishii Kazumasa , Imakita Akio , Kawawa Satoshi
Published: April 2023

With the objective of further enhancing the engine performance of the Acura brand and the environmental performance of the Honda brand in relation to the North American market, where there is a need for powertrains with driving force margin for SUVs and pickup trucks, Honda has developed a 3.0 L turbocharged engine and a 3.5 L naturally aspirated engine. Both engines adopt the same newly developed valvetrain structure and share main engine geometries.

These newly developed engines are equipped with a compact new valvetrain structure combining Hydraulic Lash Adjusters and roller rocker arms with a valve-lifter based Variable Cylinder Management system which has an internalized switching mechanism. This newly developed valvetrain made it possible to incorporate dual overhead cam structure without enlarging the cylinder head shape relative to the single overhead cam structure. It further achieves this while permitting application of a Variable Cylinder Management system and of a Variable Timing Control for intake and exhaust valves to this engine.

Sharing the main engine geometries and components for each type of engine, primarily the new valvetrain structure, also facilitated changes in reciprocating and other parts, and minor changes such as the mounting of a turbocharger and increases in fuel injection system pressure, enabling the required enhancements in engine and environmental performance to be achieved.

Regarding the turbocharged engine, the twin-scroll type turbocharger combined with the V6 engine made it possible to increase power and enhance boost pressure responsivity while preventing enlargement even over the single turbocharger. That turbocharged engine achieves maximum power of 265 kW and maximum torque at 1400 rpm of 480 Nm, raising the figures for the existing engine by 26.7% for power, and 35.2% for torque.

Regarding the natural aspiration engine, the high fuel pressure system and the multi-stage injections made it possible to reduce emissions by reducing fuel adhesion in the cylinders and enhancing homogeneity. It further enables enhancement of the thermal efficiency by combining dual Variable Timing Control and high-tumble ports and piston crown shape designed to maintain tumble flow. That natural aspiration engine achieves a maximum power of 213 kW and a maximum torque of 355 Nm. In terms of environmental performance, the thermal efficiency is 37.5%, an increase over the 36.5% of the existing engine. A vehicle equipped with this engine was also able to achieve LEV III and SULEV30 standards as well as particulate matter (PM) of 1 mg/mile.
A Compact and Efficient Modular High Pressure Diesel Common Rail Pump Platform for Future Diesel Engine Applications
Authors: Stroia Bradlee
Published: April 2023

The invention of the diesel common rail (DCR) fuel system has enabled a complete new performance scope for the operation of the Diesel Engine. Among the most important characteristics, the DCR fuel system provides increased fueling flexibility in both quantity and timing, improved packaging, relatively low weight, and attractive cost to the fuel system integrator. The four main top level requirements for DCR pumps have been identified: (1) Efficiency, (2) Function and Performance, (3) Size and Weight, and (4) Cost. In this paper, the development of key features of Stanadyne’s Modular DCR (MDCR) pump platform will first be described. Design strategies for fuel metering, robustness to debris, increased pressure, increased speed, and increase in B10 life for both an automotive MDCR pump and a heavy duty MDCR pump will be presented. Detailed results from an in-depth analysis of the pumps will be presented. Results of performance testing and durability testing will be presented. Finally, use of the pumps to meet a wide spectrum of future Diesel and Diesel Performance step applications will be discussed.
Experimental Characterization of the Mechanical Loss Components of a Single-Cylinder Spark-Ignition Engine by Progressive Disassembly Method
Authors: Romero Carlos Alberto , Ramírez Juan David , Henao Castañeda Edison de Jesús
Published: April 2023

In this work, the progressive disassembly method is used to determine the mechanical losses contributed by the different components of a single-cylinder spark ignition engine tested at crankshaft angular speeds of 300−1900 min-1, and lubricant temperatures between 30−35 °C. From the experimental measurements, the losses due to the intake and exhaust manifolds, cylinder head, valve train, camshaft bearings, connecting rod-piston assembly, flywheel, and crankshaft bearings are determined. It is obtained that the elements with the highest contribution are the piston-connecting rod assembly and the cylinder head with contributions of 19.2−36.9% and 27−33.3%, respectively. Additionally, the indicated diagram method is applied to assess the pumping, heat, and blow-by losses of the complete motored engine during the intake and exhaust processes. Pumping losses, heat and blow-by transfers, friction, and auxiliary losses are characterized, obtaining contributions between 5.8−14.7%, 14.8−37.9%, 46.4−64.6%, and 5.8−9.9% for each group of component losses, respectively.
Cross-Domain Fault Diagnosis of Powertrain System using Sparse Representation
Authors: Shen Pengfei , Bi Fengrong , Tang Daijie , Yang Xiao , Huang Meng , Guo Mingzhi , Bi Xiaoyang
Published: April 2023

Although excellent progress has been made recently in powertrain fault diagnosis based on vibration signals, most of them are based on the assumption that the fault features of the training and test data are drawn from the same probability distribution. Due to the limitation of the domain shift phenomenon, the performance of the current intelligent fault diagnosis methods is significantly reduced. Even many existing transfer learning methods have the problem of low generalization ability. Inspired by sparse representation theory, a novel cross-domain fault diagnosis method based on K-means singular value decomposition (K-SVD) and long short-term memory network (LSTM) is proposed in this study. First, K-SVD can convert source domain data into a sparse dictionary and sparse coefficient. The domain-invariant features are explored in the sparse dictionary, which contains redundant features. The sparse coefficients are input into the LSTM to obtain a primary classifier. Then, the sparse coefficients of the target domain are solved by using the sparse dictionary of the source domain. It is input into the primary classifier for fine-tuning training, and the final diagnostic classification model is obtained. The proposed method establishes knowledge transfer from the source domain to the target domain by exploring domain-invariant features in the sparse domain and bridging the distribution discrepancy. It is evaluated using powertrain operating data acquired on cross-speed, cross-load and cross-sensor working conditions. It is demonstrated that the proposed method has superior performance in dealing with data imbalance and different distributions. It offers a promising approach for industrial applications on cross-domain fault diagnosis.
Relation between Vertical, Longitudinal and Transverse Vibration in the Engine Block and Performance Parameters of an Otto Cycle Internal Combustion Engine Operated with Gasoline and Ethanol Fuel
Authors: Santana Claudio Marcio
Published: April 2023

In recent years, the use of ethanol fuel in internal combustion engines has gained importance due to environmental and commercial factors, since ethanol produces lower emission rates at similar performance parameters compared to gasoline fuel. The objective of this study is to evaluate and compare the effects of engine performance parameters on the vibration level of the engine block operated with gasoline and ethanol fuel. The experimental tests consisted of operating an Otto cycle engine on a bench dynamometer under full load conditions varying rotation and correlating the vertical, longitudinal and transverse vibration levels of the block engine with the engine performance parameters. The results showed that the engine vibration level was influenced by engine speed, load, type of fuel and performance parameters of the engine. The combustion process is primarily responsible for the highest level of vibration reached when using ethanol fuel. Under all operating conditions, the vibration level of the engine block was highest when using ethanol compared to the engine run on gasoline. On average, the transverse engine vibration was higher than vertical and longitudinal engine vibration. This study holds relevance as it correlates the vertical, longitudinal and transverse vibration level of the block of an internal combustion engine, as is found in an engine combustion process fueled by ethanol and gasoline.
Auto-Tuning PID Controller on Electromechanical Actuators Using Machine Learning
Authors: Saini Sandeep , Hernandez Jorge , Nayak Sameer
Published: April 2023

The performance of an electromechanical actuator largely depends on the control strategy implemented and calibrated. The purpose of this paper is to analyze the shortcomings of existing methods and practices involved in the manual tuning of a Proportional-Integral-Derivative (PID) controller of a Brushless DC (BLDC) motor and therefore, to propose an improved auto-tuning method. The controller investigated is a 3-stage cascaded PID, where the outermost loop is a position-based control followed by speed and current loops, respectively. The tuning method is independent of the application and provides a fast, stable, and efficient response. The motor model is first approximated to a first-order system; then mechanical parameters of the motor such as inertia and coefficient of friction are estimated using the Recursive Least Square (RLSQ) optimization method. These mechanical parameters are used in conjunction with the steady state gain and time constant of each control loop to calculate PID gain. To further improve the performance of the controller, the load torque on the motor is also estimated using an Artificial Neural Network (ANN), which is used as a feed-forward command in the current controller to improve the response of the system. The tuning method was tested on an actuator which consisted of a BLDC motor and a gear reducer. The neural network was developed by taking extensive data on the brake fixture setup. The actuator was subjected to different loads and speeds irrespective of the application load profile. The PID gains for the actuator were then calculated using the tuning rules by running the actuator on the actual application. The results demonstrate a 90% improvement in overshoot, 45% in settling time, and a 12% improvement in current consumptions against the initial baseline manual calibration.
CFD Simulation and Modelling of a Battery Thermal Management System: Comparison between Indirect and Immersion Cooling
Authors: Carello Massimiliana , Bovio Massimo , Ricci Federico , Dall'Acqua Simone , Strano Daniele Isidoro , Rizzello Alessandro
Published: April 2023

Battery Electric Vehicles (BEVs) and Hybrid Electric Vehicles (HEVs) are becoming relevant in the transportation sector, and it is therefore of utmost importance to find a solution to allow batteries to work safely and in a correct temperature range in which performance degradation and/or thermal runaway do not occur. For this purpose, a Battery Thermal Management System (BTMS) is required to ensure the correct operation of the battery pack.

The design and control of an efficient BTMS is a complex task, in which multiple technical fields are involved. The paper mainly focuses on the thermal problems affecting the BTMS and sets two main goals: 1) to provide a comparison of two possible BTMS solutions, analyzing constraints and thermal performance for the design task; 2) to present a battery thermal 1D model able to describe the battery module behavior in real-time application to be implemented in a BMS control.

The design workflow of the two BTMS proposed solutions, indirect liquid-based cooling plate and direct immersion liquid cooling, is investigated in this paper. A CFD simulation is performed to evaluate the local temperature hot spot, thermal gradient and the global thermal performance of the systems. Subsequently, to overcome the issue of high computational cost of CFD simulation, a first 1D thermal model of the immersion liquid cooling solution is properly developed for temperature evolution estimation in real-time applications. The results of the CFD simulations and of the 1D model are compared to assess the accuracy of the 1D model.
Strategies to Define Reasonable Acceptance Criteria and Validation Targets for SOTIF Assurance
Authors: Madala Kaushik , Erdos David , Krishnamoorthy Jayalekshmi , Wang Zihao , Avalos Gonzalez Carlos , Shivkumar Abhishek , Chang Melody
Published: April 2023

Acceptance criteria and validation target are the most important metrics used to measure/assure safety of the intended function (SOTIF) of an autonomous vehicle or advanced driver assistance system (ADAS). Often acceptance criteria are defined as acceptable number of fatalities, injuries or property damage events in certain hours of operation or for certain mileage driven. Validation target on the other hand is the amount of effort required in terms of hours of operation or mileage to be driven to show that the acceptance criteria is met. Although existing research details about potential values for acceptance criteria and validation target, they overlook various factors such as operational design domain, operational lifetime of a vehicle, average mileage of a vehicle, and length of roads. As a result, often acceptance criteria values are very small (e.g., 10-12 incidents/h or mi) and validation targets are very large (e.g., 1013 miles). However, these targets may not be practical to distribute within various testing avenues/platforms and provide as evidence for a given version. In this paper, we discuss the various factors and strategies we can consider for defining reasonable and practically achievable acceptance criteria and validation targets. For example, the number of miles driven by motor vehicles in United States in 2020 and the number of accidents occurred in those miles is given based on distance travelled by around 276 million vehicles. Will the distance and number of accidents remain the same even as the fleet size is 100 vehicles? In this paper, we aim to resolve such questions. Using an illustrative example, we demonstrate the usefulness of our proposed factors and strategies.
Design of a Car Battery Box with Combined Steel Stamped and Aluminum Extruded Process
Authors: Yi Xiao-Yu , Wang Xi-Hui , Shangguan Wen-Bin , Liu Yong
Published: April 2023

In the manufacturing of battery boxes using the aluminum extruded process, poor consistency of products and a short life of the die for making aluminum structural sections are usually observed. A new method of producing battery boxes is proposed that combines steel stamped and aluminum extruded process. This paper first describes the design requirements for a battery box using a new process, and several important issues such as weld seam arrangement and error proofing in the manufacturing process are discussed. To address the issue of weld seam arrangement, the following three principles should be considered in the design: These principles include that the profile lap angle should be above 90°, three or more beams should not be lapped too closely together, and multiple brackets in close proximity should be designed as one unit. Secondly, according to the maximum external dimensions of the box and the relative position of each structure, a new box was designed in two parts: the external frame and the internal frame. In the box design, the external frame is designed from both the external frame mating surface and the external mount reinforcement, while the internal frame is solely described from the design of the internal frame mating surface. Finally, the newly designed box is subjected to finite element simulation analysis, a manufacturing process study, test verification, and bead optimization. The results show that the performance of the new battery box meets the design requirements. The study of composite process battery boxes in this paper is of guiding significance for the design of battery boxes.
An Evaluation of the Sensitivity of the User-Selected Forward Collision Warning Distance in a 2017 Honda CR-V
Authors: Harrington Shawn , Nagarajan Sundar Raman
Published: April 2023

Testing was conducted to evaluate the effect on the Time to Collision (TTC) values of the visual and audible components of the Forward Collision Warning (FCW) provided by a 2017 Honda CR-V by changing the user-selected FCW Distance between Long, Normal, and Short. As part of the Honda Sensing Collision Mitigation Braking System (CMBSTM), these user-selected values change the timing of the issuance of the visual and audible warning provided to drivers. This testing evaluated the Honda at speeds of 20, 35, 50, 60, and 65 miles per hour (mph) versus a stationary live vehicle in daytime conditions in a simulated rear collision scenario. Different FCW distance settings were selected to compare the response of the system at the 20 – 65 mph range of speeds. The TTC at FCW and the distance between the Honda and the target at FCW are presented and compared at each speed and user-selected FCW Distance setting. A subset of the current research – the 20- and 35-mph tests – were compared to testing conducted by the Insurance Institute for Highway Safety (IIHS) at speeds of 12 and 25 mph.
Trajectory Planning and Tracking for Four-Wheel Independent Drive Intelligent Vehicle Based on Model Predictive Control
Authors: Wu Haidong , Long Xiang , Lu Dang
Published: April 2023

This paper proposes a dynamic obstacle avoidance system to help autonomous vehicles drive on high-speed structured roads. The system is mainly composed of trajectory planning and tracking controllers. The potential field (PF) model is introduced to establish a three-dimensional potential field for structured roads and obstacle vehicles. The trajectory planning problem that considers the vehicle’s and tires’ dynamics constraints is transformed into an optimization problem with muti-constraints by combining the model predictive control (MPC) algorithms. The trajectory tracking controller used in this paper is based on the 7 degrees of freedom (DOF) vehicle model and the UniTire tire model, which was discussed in detail in previous work [25, 26]. The controller maintains good trajectory tracking performance even under extreme driving conditions, such as roads with poor adhesion conditions, where the car’s tires enter the nonlinear region easily. The innovation of this paper lies in introducing a high-fidelity vehicle model and a muti-conditions UniTire tire model with high precision obtained after parameter identification through tire test data. In addition, the nonlinear relationship between tire lateral force and slip angle is expressed as a linear function. This method updates the equivalent cornering stiffness in the linear function by solving the slope of the secant of the tire cornering characteristic curve at the current moment online, which solves the problem of high computational complexity caused by applying complex tire models in the control system. The co-simulation results of Simulink and CarSim show that the designed system has good dynamic obstacle avoidance and driving stability performance under driving conditions with high speed and poor road adhesion.
Studies of Tire Frictional Characteristics on the Snowy Road
Authors: Zhu Hengjia , Tian Yidong , Zhang Wei
Published: April 2023

The tire frictional characteristics, which are the most critical factors of braking performance, depend on the road condition. Unsafe accidents always occur when driving in a hostile environment, especially under snowy road conditions. The coupled dynamic behaviors between the tire and the snow on the road are closely related to the water film generated from the tire rolling on the snow. The winter tire and summer tire with specification 175/65R14 are modeled separately by the finite element method (FEM), and the stiffness characteristics of the winter tire are analyzed. Further, the coupled dynamic model between the tire and the snowy road is built by considering the tire motion effects of the water film. The tires’ friction coefficient is investigated under the straight snowy road with different velocities. It shows that the friction decreases as the velocity increases, and vice versa because the intermediate water film thickness between the tire and snow depends on the tire motion state.
Load Spectrum Extraction of Double-Wishbone Independent Suspension Bracket Based on Virtual Iteration
Authors: Chang Haozheng , Gao Yunkai , Zhang Suo
Published: April 2023

The displacement of the shaft head fails to be accurately measured while the three-axle heavy-duty truck is driving on the reinforced pavement. In order to obtain accurate fatigue load spectrum of the suspension bracket, the acceleration signals of the shaft heads of the suspension obtained by the reinforced pavement test measurement are virtually iterated as responses. A more accurate model of the rigid-flexible coupled multi-body dynamics (MBD) of the whole vehicle is established by introducing a flexible frame based on the comprehensive modal theory. Furthermore, the vertical displacements of the shaft heads are obtained by the reverse solution of the virtual iterative method with well-pleasing precision.

The accuracy of the virtual iteration is verified by comparing the simulation results with the vertical acceleration of the shaft head under the reinforced pavement in the time domain and damage domain. The results show that the rms between the simulated signal and the measured signal is less than 20%, and the relative damage value is in the range of 0.5-2. It can be demonstrated that the rigid-flexible coupled MBD model of the vehicle can obtain relatively accurate iterative results. Compared to durability test results, fatigue simulation analysis using virtual iteration results can accurately predict the location of the damage. It is further verified that virtual iterations can accurately extract the load spectrum for fatigue analysis. Compared with the traditional fatigue load extraction method, the virtual iterative technique can more quickly obtain accurate loads that fails to be directly measured.
Study on State-of-the-Art Preventive Maintenance Techniques for ADS Vehicle Safety
Authors: Sanket Rohit , Hanif Athar , Ahmed Qadeer , Monohon Mark
Published: April 2023

1
Autonomous Driving Systems (ADS) are developing rapidly. As vehicle technology advances to SAE level 3 and above (L4, L5), there is a need to maximize and verify safety and operational benefits. As a result, maintenance of these ADS systems is essential which includes scheduled, condition-based, risk-based, and predictive maintenance. A lot of techniques and methods have been developed and are being used in the maintenance of conventional vehicles as well as other industries, but ADS is new technology and several of these maintenance types are still being developed as well as adapted for ADS. In this work, we are presenting a systematic literature review of the “State of the Art” knowledge for the maintenance of a fleet of ADS which includes fault diagnostics, prognostics, predictive maintenance, and preventive maintenance. We are providing statistical inference of different methodologies, comparison between methodologies, and providing our inference of different techniques that are used in other industries for maintenance that can be utilized for ADS. This paper presents a summary, main result, challenges, and opportunities of these approaches and supports new work for the maintenance of ADS.
Fuel Flow Rates for Jet-Powered Commercial Aircraft Taxi Operations
Authors:   A-21 Aircraft Noise Measurement Aviation Emission Modeling
Published: April 2023

This SAE Aerospace Information Report (AIR) summarizes prior empirical findings (AIAA 2018-3991; Chati, 2018) to recommend a modified baseline fuel flow rate model for jet-powered commercial aircraft during taxi operations on the airport surface that better reflects operational values. Existing standard modeling approaches are found to significantly overestimate the taxi fuel flow rate; therefore, a modified multiplicative factor is recommended to be applied to these existing approaches to make them more accurate. Results from the analysis of operational flight data are reported, which form the basis for the modeling enhancements being recommended.
Nickel Alloy, Corrosion- and Heat-Resistant, Bars, Forgings, and Rings Ni - 18Cr - 2.8Mo - 5.5Cb (Nb) - 0.70Ti - 1.50Al - 10Fe - 9Co - 1W Consumable Electrode Remelted or Vacuum Induction Melted 1775 °F (968 °C) Solution Heat Treated, Precipitation-Hardenable
Authors:   AMS F Corrosion and Heat Resistant Alloys Committee
Published: April 2023

This specification covers a corrosion- and heat-resistant nickel alloy in the form of bars, forgings, and flash welded rings in the solution heat-treated condition, 5 inches (127 mm) and under in nominal diameter or least distance between parallel sides (thickness) having a maximum cross-sectional area of 50 square inches (323 cm2), and stock of any size for forging, flash welded rings, or heading.