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Abstract This article presents a multistage, coupled thermal management simulation approach, informed by physical testing where available, to aid design decisions for PACCAR’s SuperTruck II hybrid truck cabin concept. Focus areas include cabin insulation, battery sizing, and sleeper curtain position, as well as heating, ventilating, and air-conditioning (HVAC) component and accessory configurations, to maintain or improve thermal comfort while saving energy. The authors analyzed weather data and determined the national vehicle miles traveled weighted temperature and solar conditions for long-haul trucks. Example weather day profiles were selected to approximate the 5th and 95th percentile weighted conditions. A daylong drive cycle was developed to impose appropriate external wind conditions during rest and driving periods.

Abstract The current publication considers several methodologies to minimize tailpipe (TP) nitrogen oxides (NOx) emissions during cold start operation. A standard, 2019 aftertreatment design of diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR)/ammonia oxidation catalyst (AMOX) was used as the baseline. Cold start NOx conversion and TP NOx emissions improvements were measured when a larger SCR, dual diesel exhaust fluid (DEF) dosing, and an electric heater were added to the exhaust configuration. Additional improvements were achieved by an improved cold start combustion mode was developed.

Abstract The increased market penetration of hybrid electric powertrains in medium heavy-duty (MHD) applications has provided a novel platform for vehicle research. One example of such a platform is the MHD parallel hybrid truck developed by Odyne Systems, LLC. In collaboration with Odyne Systems, LLC and the Department of Energy (DOE), Oak Ridge National Laboratory (ORNL) developed a validated vehicle plant model for this truck and tested the Odyne powertrain in a hardware-in-the-loop (HIL) environment. While testing in the HIL environment, the effects of reduced engine load, and thus catalyst heating, on the selective catalytic reduction (SCR) catalyst produced diminished hybrid improvement as the level of energy storage usage increased. This article will discuss these results and the potentially unforeseen interactions with modern aftertreatment systems when hybridizing conventional powertrains.

Abstract Objectified analysis and evaluation tools offer cost- as well as time-saving potentials regarding the calibration process of vehicle control units. To reduce the time required for the calibration effort, standardized processes including the frontloading of development tasks enable swift calibration procedures and can be used to develop a basis for the comparison of different vehicles and also the calibration quality. In this environment, objectified evaluation methods are also being developed for the investigation of the drivability of electric vehicles. This article presents a methodology for assessing the longitudinal drive behavior of battery electric vehicles during deceleration maneuvers. The aim is to objectively evaluate the vehicle deceleration by means of reproducible driving maneuvers. In addition to further measurement signals, the longitudinal acceleration signal serves as the main evaluation basis.

Abstract This work puts presents an all-inclusive state of the art bibliographical review of all categories of electrified transportation (xEVs) standards, issued by the most important standardization organizations. Firstly, the current status for the standards by major organizations is presented followed by the graphical representation of the number of standards issued. The review then takes into consideration the interpretation of the xEVs standards developed by all the major standardization organizations across the globe. The standards are differentiated categorically to deliver a coherent view of the current status followed by the explanation of the core of these standards. The ISO, IEC, SAE, IEEE, UL, ESO, NTCAS, JARI, JIS and ARAI electrified transportation vehicles xEV Standards from USA, Europe, Japan, China and India were evaluated. A total approximated of 283 standards in the area have been issued.

Abstract Possible oil contamination of aircraft bleed air is an ongoing operational issue for commercial aircraft. A sensitive and reliable method to detect contamination, especially at very low levels, has been elusive due, in part, to the lack of information about the physical nature of oil that results when entrained in the bleed air by an engine compressor. While it was expected that high shear rates in the compressors would result in very finely dispersed particles, detailed data on the size characteristics of these droplets were not available, making it difficult to develop reliable detection techniques. The goal of the reported research was to collect experimental data to provide this information. The concentration and size distribution of particles were measured for bleed air with different rates of controlled oil contamination under various engine operating conditions.

Abstract TOC

Abstract The growing interest from automakers and ride-hailing companies has increased the investment for high automation levels in vehicles. An important challenge in introducing autonomous vehicle (AV) technology to the market is the effort required in the validation. The research shows that AVs have to be test-driven hundreds of millions of miles to demonstrate reliability, which could take hundreds of years. Therefore, the identification of critical test scenarios and reduction of scenario sample space are urgent requirements for providing safe and reliable AVs in a time- and cost-efficient manner. This article proposes an AV test scenario generation system that creates abstract test scenarios using historical fatal accident data. The method processes and prunes the extensive fatal accident data to generate core test scenarios targeting the reasoning systems of AVs.

Abstract The power battery cooling system of a hybrid electric vehicle is composed of a fan and duct assembly with its inlet positioned inside the vehicle cabin. For the prototype vehicle considered in this work, the air inlet is positioned on the package tray due to limited feasible choices. When the battery temperature is over rated limit, the cooling fan starts to operate to cool the battery system. Propelled by the fan in the cooling system, the air in the passenger compartment enters the duct inlet, and rushes through the air duct to reach the battery pack to fulfill the intended cooling function. In this case, the rear seat occupants could clearly perceive the existence of an annoying whirring noise. In this paper, the characteristics of the battery air cooling system and its working principles are briefly described. The air inlet noise generation mechanism and its frequency characteristics are then analyzed.

Abstract Turbocharging can provide a low cost means for increasing the power output and fuel economy of an internal combustion engine. Currently, turbocharging is common in multi-cylinder engines, but due to the inconsistent nature of intake air flow, it is not commonly used in single-cylinder engines. In this article, we propose a novel method for turbocharging single-cylinder, four-stroke engines. Our method adds an air capacitor-an additional volume in series with the intake manifold, between the turbocharger compressor and the engine intake-to buffer the output from the turbocharger compressor and deliver pressurized air during the intake stroke. We analyzed the theoretical feasibility of air capacitor-based turbocharging for a single-cylinder engine, focusing on fill time, optimal volume, density gain, and thermal effects due to adiabatic compression of the intake air.

Abstract Li-ion batteries have been widely applied in the areas of personal electronic devices, stationary energy storage system and electric vehicles due to their high energy/power density, low self-discharge rate and long cycle life etc. For the better designs of both the battery cells and their thermal management systems, various numerical approaches have been proposed to investigate the thermal performance of power batteries. Without the requirement of detailed physical and thermal parameters of batteries, this article proposed a data-driven model using the adaptive neuro-fuzzy inference system (ANFIS) to predict the battery temperature with the inputs of ambient temperature, current and state of charge. Thermal response of a Li-ion battery module was experimentally evaluated under various conditions (i.e. ambient temperature of 0, 5, 10, 15 and 20 °C, and current rate of C/2, 1C and 2C) to acquire the necessary data sets for model development and validation.

Abstract This study aims to solve the problem of impact in a parallel hybrid electric system based on the continuously variable transmission (CVT) during switching from pure electric mode to engine-driven, power-generating mode. Taking into account the torque response characteristics of the engine and motor and the dynamic characteristics of the wet clutch hydraulic control system, the mode switching process is divided into six stages, namely, pure electric mode, wet-clutch free travel, engine start-up, engine speed synchronization, clutch combination, and engine intervention drive. A coordination control strategy is developed based on the model predictive control algorithm to ensure smooth mode switching. The effectiveness of the control algorithm is verified using Matlab/Simulink and the AMESim co-simulation platform. Results show that with the mode switching coordination control strategy, the components of the system work harmoniously.

Abstract To comply with the increasingly severe regulations related to exhaust emission, internal combustion engines are required to monitor their operating conditions on a continuous basis. Vibration-based techniques have been successfully applied in reciprocating engines to assess the condition of the machines and detect faults. Dealing with turbocharged engines, methodologies based on the employment of accelerometer signals to obtain an estimation of the turbocharger rotation have been proposed with the aim of using the instantaneous turbocharger speed for the engine function monitoring. The present article focuses on the analysis in time and frequency domains of the vibration signals from the compressor housing of a medium-duty, four-cylinder, turbocharged common rail diesel engine aimed at indirectly evaluating the turbocharger speed in terms of its mean component and fluctuation. Data have been acquired during experimental tests at different values of engine speed and torque.

Abstract To address the difficulties in modeling the starting process of dual-clutch transmission (DCT) vehicles and poor adaptability of vehicles in complex driving conditions, this article proposes a new modeling and control strategy for the DCT starting system based on data-driven autoregressive moving average exogenous (ARMAX) modeling. Firstly, the DCT starting process is considered equivalent to the time series-related ARMAX model, and a data-driven ARMAX model could be obtained using input-output data relating to the starting process; also, the effectiveness of the data-driven ARMAX modeling technique is verified using the starting test of a real vehicle. Secondly, a data-driven adaptive model predictive control (A-MPC) strategy, which synthetically considers driving intention and clutch engagement status, is proposed.

Abstract In the development of hydrocarbon (HC) traps for E85 fuel vehicle emission control, the addition of palladium (Pd) to BEA zeolite was studied for trapping and decreasing cold-start ethanol emissions. BEA zeolite after a laboratory aging at 750°C for 25 hours released nearly all of the trapped ethanol as unconverted ethanol at low temperature, and some ethene was released at a higher temperature by a dehydration reaction. The addition of Pd to BEA zeolite showed a decrease in the release of unconverted ethanol emissions even after the lab aging. The release of methane (CH4), acetaldehyde (CH3CHO), carbon monoxide (CO), and CO2 from Pd-BEA zeolite during desorption (temperature programmed desorption (TPD)) demonstrated that multiple ethanol reaction mechanisms were involved including dehydrogenation and decomposition reactions.

Abstract This study on engine journal bearing wear is based on a simulation approach using the engine start-up condition. This study presents an attempt to predict the potential regions where a wear scar would occur on crankshaft bearings, and estimates the instantaneous wear volume for bearings operating at a variable angular velocity of a shaft at the beginning of the real firing start-up cycle. The potential wear regions are discovered by finding the minimum oil film thickness at every crank angle (CA) existing below most oil film thickness scarring wear (MOFTSW) obtained by the concept of the centerline average surface roughness (cla = Ra). The simulation results give an increased understanding of when and where a wear scar may occur in the journal bearings for the firing start-up condition.

Abstract Present-day vehicles come with a variety of new features like the pre-crash warning, the vehicle-to-vehicle communication, semi-autonomous driving systems, telematics, drive by wire. They demand very high bandwidth from in-vehicle networks. Various ECUs present inside the automotive transmits useful information via automotive multiplexing. Transmission of data in real-time achieves optimum functionality. The high bandwidth and high-speed requirement can be achieved either by using multiple buses or by implementing higher bandwidth. But, by doing so, the cost of the network as well as the complexity of the wiring increases. Another option is to implement higher layer protocol which can reduce the amount of data transferred by using data reduction (DR) techniques, thus reducing the bandwidth usage. The implementation cost is minimal as the changes are required in the software only and not in hardware.

Abstract In this work, a three-phase integrated onboard battery charger is investigated and implemented for electric vehicle (EV) applications. A three-switch add-on interface is introduced to connect with the inverter and the motor windings, such that a two-channel interleaved boost converter is formed for the battery charging. The detailed system analysis, design methodology, and control strategy are discussed. Moreover, a simulation study is carried out to validate the effectiveness of the proposed integrated charger. As verification, a 5 kW liquid-cooled prototype is built and tested. The proposed integrated charging system achieves a power factor of 0.99, and total harmonic distortion (THD) of 4.82% at 5 kW with an efficiency of 93.2%.

Abstract Current advances in connected and automated mobility claim to change driving scenarios worldwide. Nevertheless, the impact of automated mobility on the design of vehicle powertrains still need exhaustive assessment. In this article, a design methodology is proposed for BEV powertrains that integrates the consideration of vehicle-to-vehicle (V2V) connected driving. Particularly, each analyzed design solution is evaluated in standard drive cycles both as normal human-operated vehicle and as following car in automated V2V driving. The overall battery energy consumption for the latter case is evaluated by solving an optimization problem to determine off-line the most suitable vehicle speed trajectory. Remaining design requirements include vehicle maximum speed, acceleration capability, and gradeability. Obtained results aim at quantifying the amount of energy savings for V2V automated driving depending on the considered mission and BEV powertrain design.

Abstract This article presents a control strategy to improve the overall energy efficiency of connected and automated-hybrid electric vehicles (CA-HEV) in urban driving conditions. A forward-looking, traffic-aware, high-level decision control (HLDC) algorithm is proposed in this article, where both traffic and road information (obtained from surrounding vehicles and municipal traffic management centers through connected vehicle technologies) are utilized. The objective is to dynamically optimize the vehicle speed trajectories to reduce, and potentially eliminate, idling time at red traffic lights. The benefits include reduced unnecessary engine restart, emissions, and an improvement in the overall energy efficiency of the CA-HEV.