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Viewing 1 to 30 of 1601
2018-04-03
Technical Paper
2018-01-1134
Shouvik Dev, Navjot Singh Sandhu, Mark Ives, Shui Yu, Ming Zheng, Jimi Tjong
Close-loop feedback combustion control is essential for improving the internal combustion engines to meet the rigorous fuel efficiency demands and emission legislations. A vital part is the combustion sensing technology that diagnoses in-cylinder combustion information promptly, such as using cylinder pressure sensor and ion current measurement. The promptness and fidelity of the diagnostic are particularly important to the potential success of using intra-cycle control for abnormal cycles such as super knocking and misfiring. Enormous researches have demonstrated the use of ion-current sensing as feedback signal to control the spark ignition gasoline engines, with the spark gap shared for both ignition and ion-current detection. The conventional technique cannot extract the combustion ion-current from the measured signal during the sparking process, since the sparking current overwhelms the combustion ion current.
2018-04-03
Technical Paper
2018-01-1288
Zefang Xu, Nagesh Gummadi, Daniel Woytowich, Abdelkrim Zouani
FEA-Based Simulation of Exhaust Hanger Forces ABSTRACT Exhaust system can be a source of vibrations that transmit inside the vehicle thru the exhaust hangers. These vibrations are caused by engine excitations under acceleration. During the upfront development stage, it is important to predict accurately the forces at the exhaust hangers in order to drive a robust exhaust system design and prevent objectionable noise and vibrations inside the vehicle. This paper describes an FEA-based simulation method to predict the exhaust hanger forces. It demonstrates the effect of temperature on the exhaust dynamic behavior and its importance for an accurate prediction of the exhaust hanger forces.
2018-04-03
Technical Paper
2018-01-0558
Donald F. Tandy, Clay Coleman, Robert Pascarella
In repeated physical testing of vehicles at or near their handling limit, tire shoulder wear occurs that is not typical of normal customer use. It has been observed for decades that this type of severe cornering induced tire wear can have a significant effect on the force and moment characteristics of tires. In this study, this the severe cornering wear effect was studied by testing vehicles in a controlled manner using a robot steering controller. This testing shows how a vehicles response to steering inputs change significantly as the number of runs on the same tires accumulates. Additionally, for one vehicle configuration an additional run was made with tires that had accumulated 10,000 miles of customer usage. The results of that test confirmed that changes in vehicle response due to severe cornering are not observed on tires worn in a typical manner.
2018-04-03
Technical Paper
2018-01-0556
Donald F. Tandy, Robert Pascarella, Clay Coleman
There has been a general consensus in the scientific literature that a rim gouging, not scraping, into a roadway surface generates very high forces which can cause a vehicle to overturn in some situations. However, a paper published in 2004 attempts to minimize the forces created during wheel rim gouging and the effect on vehicle rollover. This paper relied largely on heavily filtered lateral acceleration data and discounted additional test runs by the authors and NHTSA that did not support the supposed conclusions. This paper will discuss the effect of rim gouging using accepted scientific methods, including full vehicle testing where vehicle accelerations were measured during actual rim gouging events and static testing of side forces exerted by wheels mounted on a moving test fixture. The data analyzed in this paper clearly shows that forces created by rim gouges on pavement can be very high and can contribute to vehicle rollover.
2018-04-03
Technical Paper
2018-01-0583
Zhao Liu, Ping Zhu, Liwei Wang, Ching-Hung Chuang
Because of rising complexity during the automotive product development process, the number of disciplines to be concerned has been significantly increased. Multidisciplinary design optimization (MDO) methodology, which provides an opportunity to integrate each discipline and conduct compromise searching process, is investigated and introduced to achieve the best compromise solution for the automotive industry. To make a better application of MDO, the suitable coupling strategy of different disciplines and efficient optimization technique for automotive design are studied in this paper. Firstly, considering the characteristics of automotive load cases which include many shared variables whereas rare coupling variables, a multilevel MDO coupling strategy based on enhanced collaborative optimization is studied to improve the computational efficiency of MDO problems.
2018-04-03
Technical Paper
2018-01-0584
Junqi Yang, Ching-Hung Chuang, Zhenfei Zhan, Hongyi Xu, Gang Guo
This paper presents a design process with data mining technique and advanced optimization strategy. The proposed design method provides insights in three aspects. First, data mining technique is employed for sensitivity study to select key factors of design variables. Second, relationship between multiple types of size and shape design variables and performance responses can be investigated based on sufficient training data. Last but not least, design preference can be initialized based on data analysis to provide priori guidance for the starting design points of optimization algorithm. An exhaust system design problem which largely contributes to the improvement of vehicular Noise, Vibration and Harshness (NVH) performance is employed for the illustration of the process. . Two types of design parameters, structural variable (gauge of component) and layout variable (hanger location), are considered in the studied case.
2018-04-03
Technical Paper
2018-01-0008
Rajagopal Jayaraman, Adit Joshi, Viet To, Ghamdan Kaid
The propulsion system of a power-split hybrid vehicle typically comprises of an engine drive system in which the engine, drivetrain and generator are mechanically coupled on a planetary gear set driveline while the electric drive system consists of a high voltage battery and a traction motor. Traditionally, Hardware-in-the-Loop (HIL) simulations of hybrid vehicle controls and high-voltage battery controls have been implemented on separate HIL benches which were exclusively targeted to hybrid vehicle controls and battery controls simulations respectively. This research demonstrates an implementation of enhanced fidelity of a power-split hybrid vehicle powertrain controls HIL by integrating it with high- voltage traction battery subsystem HIL by networking the two aforementioned HIL systems together.
2018-04-03
Technical Paper
2018-01-0082
Eric C. Myers, Syed Ali
Jet pumps are viable options of pumping fluid if a pressurized flow stream is available as an energy source. For a Ford engine cooling circuit an effort was undertaken to improve an existing (conventional) jet pump design which could not meet more demanding pumped flow requirements. Various virtual jet pump designs were analyzed using 3D CFD where the pumped flowrate was used to evaluate the effectiveness of the design. It was found that the existing design could not be modified to provide the needed pump flow rate. It was decided to forgo the current design and develop a completely new configuration. This effort produced many design variances which were evaluated and resulted in a final design that closely reached the pumped flow rate requirements. As new designs were evaluated through the process, particular geometrical aspects were observed which improved the pumped flow performance.
2018-04-03
Technical Paper
2018-01-0042
William Buller, Helen Kourous, Jakob Hoellerbauer
One of the principal bottlenecks for sensing and perception algorithm development for autonomous vehicles is the ability to evaluate tracking algorithms against ground truth data. By ground truth we mean independent knowledge of the position, size, speed, heading, and class of objects of interest (moving and stationary) in complex operational environments. Our goal was to execute a data collection campaign at an urban test track in which trajectories of moving objects of interest are measured with auxiliary instrumentation, in conjunction with several AVs with a full sensor suite of radar, LiDAR, and cameras. Multiple autonomous vehicles (both moving and stationary) collected measurements in a variety of scenarios designed to incorporate real world interactions of vehicles with bicyclists and pedestrians. Trajectory data for a set of bicyclists and pedestrians was collected by separate means.
2018-04-03
Technical Paper
2018-01-0062
Ravi Rungta, NOORI PANDIT
There is an ongoing effort at Ford Motor Company to develop an accelerated corrosion test for automotive heat exchangers. This has become even more important as automakers are focusing on corrosion durability of 15 years in the field versus current target of 10 years. To this end an acid immersion test was developed and reported in a previous paper for condensers (1). This paper extends those results to evaporators and establishes the efficacy of the test using these results and those reported in the literature. The paper also discusses variability in corrosion test results as observed in tests such as SWAAT and salt/SO2, and its relation to field durability. 1. Rungta, R. and Pandit, N., “A Rapid Screening Test to Assess Relative Corrosion Performance of Automotive Condensers,” SAE Technical Paper 2017-01-0174, 2017.
2018-04-03
Technical Paper
2018-01-1411
WENKAI Li, Carlos Engler-Pinto, Xuming Su, Ziang li
Ultrasonic fatigue tests (testing frequency around 20kHz) have been conducted on A356 aluminum alloys with different Cu contents and AS7GU aluminum alloy. Tests were performed in dry air and submerged in water. The effect of Cu percentage was investigated, it was concluded that under the same Cu percentage, the material strength may be the key factor influencing the environment humidity effect in ultrasonic fatigue testing.
2018-04-03
Technical Paper
2018-01-1410
Wei-Jen Lai, Carlos Engler-Pinto
An innovative specimen design and test system for thermal fatigue (TF) analysis is developed to compare the fatigue behavior of different cylinder head materials under realistic cyclic thermal loadings. Finite element analyses were performed to optimize the specimen geometry and thermal cycles. The reduced section of the TF specimen is heated locally by a high frequency induction heater and cooled by compressed air. The mechanical strain is then induced internally by the non-uniform thermal gradient generated within the specimen to closely simulate what valve bridges in cylinder heads experience in real operation. The resulting fatigue life is a function not only of the inherent fatigue resistance of the alloys, but also of other relevant properties such as thermal conductivity, modulus of elasticity, and coefficient of thermal expansion. This test is an essential tool for comparing different alloys for thermal fatigue applications.
2018-04-03
Technical Paper
2018-01-1444
Krishnakanth Aekbote, Clifford Chou, James Cheng, King Yang, John Cavanaugh, Stephen Rouhana, Jamel Belwafa
An understanding of stiffness characteristics of different body regions, such as thorax, abdomen and pelvis of ES-2re and SID-IIs dummies under controlled laboratory test conditions is essential for development of both compatible performance targets for countermeasures and occupant protection strategies to meet the recently updated FMVSS214, LINCAP and IIHS Dynamic Side Impact Test requirements. The primary purpose of this study is to determine the transfer functions between the ES-2re and SID-IIs dummies for different body regions under identical test conditions using flat rigid wall sled tests. The experimental set-up consists of a flat rigid wall with five instrumented load wall plates aligned with dummy's shoulder, thorax, abdomen, pelvis and femur/knee impacting a stationary dummy seated on a rigid low friction seat at a pre-determined velocity.
2018-04-03
Technical Paper
2018-01-1448
Krishnakanth Aekbote, Clifford Chou, John Cavanaugh, James Cheng, Jamel Belwafa, King Yang, Stephen Rouhana
The main purpose of this study was to determine the impact responses of the different body regions (shoulder, thorax, abdomen and pelvis/leg) of the ES-2re and SID-IIs dummies using rigid wall impacts under different initial test conditions. The experimental set-up consisted of a flat rigid wall with five instrumented load wall plates aligned with dummy's shoulder, thorax, abdomen, pelvis and knee impacting a stationary dummy seated on a rigid seat at a pre-determined velocity. The relative location and orientation of the load wall plates was adjusted relative to the body regions of the ES-2re and SID-IIs dummies respectively.
2018-04-03
Technical Paper
2018-01-1449
Krishnakanth Aekbote, Clifford Chou, John Cavanaugh, James Cheng, King Yang, Stephen Rouhana, Jamel Belwafa
The main purpose of this study was to determine the impact responses of the different body regions (shoulder, thorax, abdomen and pelvis/leg) of the ES-2re and SID-IIs dummies using rigid wall impacts under different initial test conditions. The experimental set-up consisted of a flat rigid wall with five instrumented load walls aligned with dummy's shoulder, thorax, abdomen, pelvis and knee impacting a stationary dummy seated on a rigid seat at a pre-determined velocity. The relative location and orientation of the load wall was adjusted relative to the body regions of the ES-2re and SID-IIs dummies respectively.
2018-04-03
Technical Paper
2018-01-1360
Ondrej Santin, Jaroslav Beran, Ondřej Mikuláš, Jaroslav Pekar, John Michelini, Steven Szwabowski, Shankar Mohan, Dimitar Filev, Junbo Jing, Umit Ozguner
In order to improve the fuel economy while in cruise, the Model Predictive Control (MPC) technology has been adopted utilizing the road grade preview information and allowance of the vehicle speed variation. This paper is focused on robustness study of delivered fuel economy benefit of Adaptive Nonlinear Model Predictive Controller (ANLMPC) reported earlier to several noise factors, e.g. vehicle platform, vehicle weight, fuel type etc. Further, as the vehicle position is obtained via GPS with finite precision and source of road grade preview might be inaccurate, the effect of inaccurate information of the road grade preview worsen the fuel economy benefits is studied and remedy to it is established.
2018-04-03
Technical Paper
2018-01-1331
Noelle Baker, Scott Henry, Tony Laituri
An eleven-group taxonomy was created to classify real-world side crashes from the Crashworthiness Data System (CDS) component of the National Automotive Sampling System (NASS). Three steps were taken to develop the taxonomy: (1) side-impact towaway crashes were identified by examining 1987-2016 model year light passenger vehicles with Collision Deformation Classification (CDC) data from the 1997-2015 calendar years of NASS; (2) case reviews, engineering judgments, and categorization assessments were conducted on these data to produce the eleven-group taxonomy; and (3) taxonomy groups were reviewed relative to regulated crash test procedures. "Oblique" and "Partial Perpendicular F" crashes were the most frequent crash types, each contributing approximately 22% to the total, followed closely by “No Wheel Engaged P” contributing approximately 19%. The “No Wheel Engaged P” group was also the most highly represented crash type for vehicles with at least one seriously-injured occupant.
2018-04-03
Technical Paper
2018-01-0098
Zhangxing Chen, Manlin Wang, Yimin Shao, Qingping Sun, Haibin Tang, Hongyi Xu, Katherine Avery, Danielle Zeng, Xuming Su
Chopped carbon fiber sheet molding compound(SMC) material is a promising candidate for mass-production vehicle components. However, the experimental characterization of SMC material property is still a challenging task and needs to be further investigated. There now exists two ASTM standards (ASTM D7078/D7078M and ASTM D5379/D5379M) for characterizing the shear properties of composite materials. However, which standard is suitable for SMC material characterization is still unknown. To find out a suitable way for characterize the shear property of SMC material, Digital Image Correlation(DIC) shear tests according to two standards are conducted separately to make a comparison. The results show that none of the test samples according to ASTM are valid. Moreover, the failure mode of these samples indicate that the failure is caused by the additional moment raised by the improper design of the fixture.
2018-04-03
Technical Paper
2018-01-0149
Xianjun Sun, Srikar Vallury, Lingxuan Su, Patricia Tibbenham, Hong-Tae Kang, Anthony Yang, Xuming Su, Danielle Zeng
Warpage is the distortion induced by inhomogeneous shrinkage during injection molding of plastic parts. The uncontrolled warpage will result in dimensional instability and bring a lot of challenges to the mold design and part assembly. Current commercial simulation software for injection molding cannot provide consistently accurate warpage prediction, especially for semi-crystalline thermoplastics. In this study, the root cause of the inconsistency in warpage prediction has been investigated by using injection molded polypropylene plaques with a wide range of process conditions. The warpage of injection molded plaques are measured and compared to the numerical predictions from Moldex3D. The study shows that with considering cooling rate effect on crystallization kinetics and using of the improved material model for residual stress calculations, good agreements are obtained between experiment and simulation results.
2018-04-03
Technical Paper
2018-01-0228
Stephen Busch, Kan Zha, Eric Kurtz, Alok Warey, Richard Peterson
In light- and medium-duty diesel engines, piston bowl shape influences thermal efficiency, either due to changes in wall heat loss or to changes in the heat release rate. The relative contributions of these two factors are not clearly described in the literature. In this work, two production piston bowls are adapted for use in a single cylinder research engine: a conventional, re-entrant piston, and a stepped-lip piston. An injection timing sweep is performed at constant load with each piston, and heat release analyses provide information about thermal efficiency, wall heat loss, and the degree of constant volume combustion. Zero-dimensional thermodynamic simulations provide further insight and support for the experimental results. The effect of bowl geometry on wall heat loss depends on injection timing, but changes in wall heat loss cannot explain changes in efficiency.
2018-04-03
Technical Paper
2018-01-0230
Kan Zha, Stephen Busch, Alok Warey, Richard C. Peterson, Eric Kurtz
In light-duty, direct injection (DI) diesel engines, combustion chamber geometry influences the complex interactions between swirl and squish flows, spray-wall interactions as well as late-cycle mixing. Because of these interactions, piston bowl geometry significantly affects fuel efficiency and emissions behavior. However, due to lack of reliable in-cylinder measurements, the mechanisms responsible for piston-induced changes in engine performance are not well understood. Non-intrusive, in-situ optical measurement techniques are necessary to provide a deeper understanding of the piston geometry effect on in-cylinder processes and to assist in the development of predictive engine simulation models. This study compares two substantially different piston bowls with geometries representative of existing technology: a conventional re-entrant bowl and a stepped-lip bowl. Both pistons are tested in a single-cylinder optical diesel engine under identical boundary conditions.
2018-04-03
Technical Paper
2018-01-0462
Zhuxian Xu, Chingchi Chen, Thomas Lei
SiC devices have inherent fast switching capabilities due to their superior material properties, and are considered potential candidates to replace Si devices for traction inverters in electrified vehicles in future. However, SiC devices usually have a lower gate threshold voltage Vg(th) (2-4V) than that of Si devices (6-7V). The characteristics make SiC devices prone to the crosstalk between upper and lower devices especially during fast switching. For example, when a lower device is turning on, the upper device is supposed to be in the off state. However, the gate of upper device may be charged through the parasitic inductance / capacitance and goes beyond gate threshold voltage Vg(th), which results in the false turn-on of upper device. The crosstalk causes excessive switching loss, device overstress, and even device failure. In this paper, the root cause of the crosstalk phenomenon and excessive ringing is identified through experiments.
2018-04-03
Technical Paper
2018-01-0464
Xi Lu, Kewei Xiao, Guangyin Lei, Chingchi Chen
In this paper, the high-temperature capability of the traction inverter was investigated by applying coolant with temperature much higher than the typical allowed value until the system fails. The purpose of this study is to identify the weakest link of the traction inverter system in terms of temperature. This study was divided into two stages. In the first stage, a series of nondestructive tests were carried out to investigate the key component temperature rise (ΔT) above coolant temperature as a function of the outside controllable parameters, such as dc link voltage, phase current, and switching frequency. The key components include power modules, gate driver board, gate driver power supply, bus bar near current sensors, and dc link capacitor. Their temperatures were tracked and recorded by thermocouples or on-die temperature sensors.
2018-04-03
Technical Paper
2018-01-0452
Baoming Ge, Lihua Chen, Shahram Zarei
A typical Hybrid Electric Vehicle (HEV) drive system includes a traction motor drive, a generator drive, and a boost converter. Both motor and generator can operate in motoring or generating modes, the former operation mode consumes power/energy and the latter operation mode produces power/energy. These three parts are coupled via the capacitor based DC bus, where low voltage of battery is boosted by the boost converter to a high level for enhancing performance of the traction motor drive. The boost converter is to ensure a desired constant DC bus voltage regardless of what powers of the motor/generator inverter consuming or generating. The existing control methods of boost converter employ DC bus voltage closed-loop control and inductor current closed-loop control, combined with pulse width modulation (PWM) to maintain a constant DC bus voltage. This control method has intrinsic performance limitations for dynamic response.
2018-04-03
Technical Paper
2018-01-0481
Sujeendran S, Selvakumar Palani, Da Wei Li, Balajikumar Srinivasan, Jerry Lai, Youssef Ziada
During the assembly process of planetary gear, the pinion shaft is initially press-in to the planetary carrier and then staking is performed for affixing pinion shaft onto the position. The main purpose of staking process is to prevent the movement of pinion shaft during transmission operation with minimal distortion of the assembly. During the press-in process, pinion shaft and carrier are subjected to extremely high friction due to interference fit. In staking process, the pinion shaft top and bottom ends are deforming permanently and becoming a lump structure to hold the shaft in position. Pinion shaft should sustain certain axial force exerted by helical planetary gears, which tends to push the carrier flange out of position during operation. Staking length, staking force and interference between shaft and carrier hole are the critical parameters, which determine the maximum axial force that pinion shaft can withstand.
2018-04-03
Technical Paper
2018-01-0479
Shuxin gu, Reda Adimi, C. Hsieh
With strict government requirements for automobile fuel economy and global climate warming concerns, powertrain design becomes ever more challenging and complicated. New technologies come out daily, and each component, small or large, is scrutinized for weight, cost, performance, etc. To meet these ever demanding requirements, Computer Aided Engineering (CAE) becomes very critical in the product development process. It not only saves tremendous developing time and cost, but also helps discover new and innovative ideas very quickly. Digital product development process is an industrial norm nowadays. Parts are modeled in 3D in a Computer Aided Design (CAD) system, and then they are passed to and modeled in a Finite Elements Analysis (FEA) software package for analysis. If the analysis results do not meet the requirements, engineers either modify the FEA models or 3D CAD geometry for re-analysis.
2018-04-03
Technical Paper
2018-01-0487
Wen Dai, Eric W. Curtis, Kim Hwe Ku, Wolfram Buschhaus, Peter D. Kuechler
Vehicle designs usually do not mature until late in the development cycle when available time to make certain hardware changes for vehicle system optimization becomes impossible. As a result, the designs of many components and various actuators cannot be optimized on the vehicle system level. A good example would be the vehicle transient performance in launch acceleration of different engine cam profiles. In lieu of hardware tests, Computer Aided Engineering (CAE) tools are often used to optimize component designs systematically. This normally requires the modeling of the vehicle with full controls and mature calibrations. Both full controls and mature calibrations, however, wouldn’t be available until late during the vehicle development cycle. Putting together a vehicle system model with full controls and mature calibrations is also very time consuming and often with prohibitive workloads to support the designs of all components.
2018-04-03
Technical Paper
2018-01-0318
Patrick Phlips, David Scholl
To study the feasibility of fleet CO2 regulations, government agencies have been simulating the entire vehicle fleet with a large number of powertrain technology combinations. The modelling is based on component data from benchmarking or suppliers. One difficulty with this ‘bottom up’ approach is that the agencies have a limited understanding of the many requirements and constraints involved, and may therefore come to optimistic conclusions. As many of the technologies under investigation are already being used on individual vehicles today, it is proposed here to take the ‘top down’ view of studying what these technologies actually achieve. The required data was combined from the EPA Test Car List and the DOE Fuel Economy Guide. Powertrain technologies are characterized by estimating statistically a simple physical model of fuel consumption for groups of vehicles sharing the same technology.
2018-04-03
Technical Paper
2018-01-0322
Patrick Phlips, Mrudula Orpe, Genesis Vasquez
Decoupling Vehicle Work from Powertrain Properties in Fuel Consumption Prediction Patrick Phlips, Mrudula Orpe, Genesis Vasquez Ford Motor Company To study the feasibility of fleet CO2 regulations, government agencies have been simulating the entire vehicle fleet with a large number of engine and transmission technology combinations. In addition, this multitude of possibilities is multiplied by the multitude of variations in vehicle weights, tires and aerodynamic resistances. The result is that, even for a single level of performance per vehicle, over 100,000 drive cycle simulations are required to compute the possible range of outcomes for a fleet of vehicles. The emerging theoretical understanding of the linkage of vehicle fuel consumption to engine properties suggests that, for any one powertrain, the vehicle fuel consumption on a drive cycle is proportional to the total work delivered by the powertrain to the vehicle.
2018-04-03
Technical Paper
2018-01-0670
Dominique Meroux, Gil Tal
Plug-in hybrid (PHEV) technology offers the ability to achieve zero tailpipe emissions coupled with convenient refueling. Fleet adoption of PHEVs, often motivated by organizational and regulatory sustainability targets, may not always align with optimal use cases. In a car rental application, barriers to improving fuel economy over a conventional hybrid include: diminished benefits of additional battery capacity on long-distance trips, sparse electric charging infrastructure at the fleet location, lack of renter understanding of electric charging options, and a principle-agent problem where the driver accrues fewer benefits than costs for actions that improve fuel economy, like charging and eco-driving. This study uses high-resolution driving data collected from twelve Ford Fusion Energi sedans owned by University of California, Davis (UC Davis), where the vehicles are rented out for university-related activities.
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