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Methods of Pegging Cylinder Pressure to Maximize Data Quality

Michigan Tech APS LABS-Jeremy Worm
Michigan Technological Univ-Darrell Robinette
Published 2019-04-02 by SAE International in United States
Engine cylinder pressure is traditionally measured with a piezo-electric pressure transducer, and as such, must be referenced or pegged to a known value. Frequently, the cylinder pressure is pegged to the pressure in the intake manifold plenum whereby the manifold absolute pressure (MAP) at the end of the intake stroke is measured and the cylinder pressure trace for the entire cycle is adjusted such that the cylinder pressure is set equal to the manifold pressure at the end of the intake stroke. However, any error in pegging induces an error in the cylinder pressure trace, which has an adverse effect on the entire combustion analysis. This research is focused on assessing the pegging error for several pegging methods across a wide range of engine operating conditions, and ultimately determining best practices to minimize error in pegging and the calculated combustion metrics. The study was conducted through 1D simulations using the commercially available GT-Power. The test matrix included variations of speed, load, intake runner length and intake valve timing. Five different pegging locations were compared, and…
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Cooling Fan Selection in Power Car Application Using CFD and FEA Analysis

Cummins Inc.-Mukesh Kumar, Vitthal Khandagale, Prashant Kelkar, Rohit Saha
Published 2019-04-02 by SAE International in United States
This paper describes the methodology used to select an application-based fan that has optimum operating characteristics in terms of cooling air flow rate, fan power, and noise. The selected fan is then evaluated for structural strength.To evaluate different fans, complete rail coach under-hood simulations were carried out using steady-state 3D computational fluid dynamics (CFD) approach. These simulations considered an actual, highly non-uniform flow field. For each fan option, fan power, air flow rate, and surface acoustic power was evaluated. Pressure profiles on the fan blades were studied to assess the effect of non-uniform downstream air passage designs. Surface acoustic power was calculated using broadband noise source (BNS) model in ANSYS Fluent®. Surface pressure profiles over fan blades imported from 3D CFD were used in finite element analysis (FEA) in ANSYS. Analyses were carried out for blade linear and non-linear properties. Equivalent fully reversed (EFR) stress was calculated based on an internal code that uses Goodman theory.It can be concluded from simulation study that the fluid structural coupled approach can be used to predict and optimize…
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Machine Learning with Decision Trees and Multi-Armed Bandits: An Interactive Vehicle Recommender System

Carnegie Mellon University-Tong Yu, Ole Mengshoel
Ford Motor Co., Ltd.-Dominique Meroux, Zhen Jiang
Published 2019-04-02 by SAE International in United States
Recommender systems guide a user to useful objects in a large space of possible options in a personalized way. In this paper, we study recommender systems for vehicles. Compared to previous research on recommender systems in other domains (e.g., movies or music), there are two major challenges associated with recommending vehicles. First, typical customers purchase fewer cars than movies or pieces of music. Thus, it is difficult to obtain rich information about a customer’s vehicle purchase history. Second, content information obtained about a customer (e.g., demographics, vehicle preferences, etc.) is also difficult to acquire during a relatively short stay in a dealership. To address these two challenges, we propose an interactive vehicle recommender system based a novel machine learning method that integrates decision trees and multi-armed bandits. Decision tree learning effectively selects important questions to ask the customer and encodes the customer's key preferences. With these preferences as prior information, the multi-armed bandit algorithm, using Thompson sampling, efficiently leverages the user’s feedback to improve the recommendations in an online fashion. The empirical results show that…
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A Study on Control Logic Design for Power Seat

Hyundai Motor Co.-Misun Kwon, Taehoon Lee, Sangdo Park
Published 2019-04-02 by SAE International in United States
The large luxury sedan seat has a 22-way Movement. It offers a wide range of adjustments to enhance passenger comfort performance while it has many constraints on movement in constrained indoor space. In addition, the power seat is operated by a motor, which makes it difficult for the user to determine the amount of adjustment, unlike determining the amount of adjustment by the power and feel of a person, such as manual seat adjustment. IMS, one-touch mode, is also constrained by parameters such as indoor space package, user's lifestyle, etc. during function playback. This paper aims to design the seat control logic to achieve the best seat comfort while satisfying each constraint.The results of this study are as follows. Increase robustness of power seat control logic.Provide optimal adjustments and comfort at each location.Offer differentiated custom control and seating modes for each seat.Improve customer satisfaction and quality by upgrading software.
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A Quasi-Dimensional Model of Pre-Chamber Spark-Ignition Engines

FEV Engine Technology-Knut Habermann
University of Naples-Fabio Bozza, Vincenzo De Bellis, Daniela Tufano, Enrica Malfi
Published 2019-04-02 by SAE International in United States
Increasingly stringent pollutant and CO2 emission standards require the car manufacturers to investigate innovative solutions to further improve the fuel economy of their fleets. Among these techniques, an extremely lean combustion has a large potential to simultaneously reduce the NOx raw emissions and the fuel consumption of spark-ignition engines. Application of pre-chamber ignition systems is a promising solution to realize a favorable air/fuel mixture ignitability and an adequate combustion speed, even with very lean mixtures.In this work, the combustion characteristics of an active pre-chamber system are experimentally investigated using a single-cylinder research engine. Conventional gasoline fuel is injected into the main chamber, while the pre-chamber is fed with compressed natural gas. In a first stage, an experimental campaign was carried out at various speeds, spark timings and air-fuel ratios. Global engine operating parameters as well as cylinder pressure traces, inside main combustion chamber and pre-chamber, were recorded and analyzed.Based on the available experimental data, a phenomenological model of this unconventional combustion system with divided combustion chambers was developed and validated. The model was then implemented…
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Heavy-Duty Aerodynamic Testing for CO2 Certification: A Methodology Comparison

Intl. Council on Clean Transportation-J. Felipe Rodriguez, Oscar Delgado
University of Technology Graz-Martin Rexeis, Martin Röck
Published 2019-04-02 by SAE International in United States
Aerodynamic drag testing is a key component of the CO2 certification schemes for heavy-duty vehicles around the world. This paper presents and compares the regulatory approaches for measuring the drag coefficient of heavy-duty vehicles in Europe, which uses a constant-speed test, and in the United States and Canada, which use a coastdown test. Two European trucks and one North American truck were tested using the constant-speed and coastdown methods. When corrected to zero yaw angle, a difference of up to 12% was observed in the measured drag coefficients from the US coastdown procedure and the EU constant-speed test. The differences in the measured drag coefficient can be attributed, among others, to the assumptions in the speed-dependence of the tire rolling resistance and axle spin losses, the data post-processing required by each methodology, unaccounted frictional losses in the transmission, the behavior of the automated manual transmission during the coastdown run, and the yaw angle correction.
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PHEV Real World Driving Cycle Energy and Fuel and Consumption Reduction Potential for Connected and Automated Vehicles

Michigan Technological University-Darrell Robinette, Eric Kostreva, Alexandra Krisztian, Anthony Lackey, Christopher Morgan, Joshua Orlando, Neeraj Rama
Published 2019-04-02 by SAE International in United States
This paper presents real-world driving energy and fuel consumption results for the second-generation Chevrolet Volt plug-in hybrid electric vehicle (PHEV). A drive cycle, local to Michigan Technological University, was designed to mimic urban and highway driving test cycles in terms of distance, transients and average velocity, but with significant elevation changes to establish an energy intensive real-world driving cycle for assessing potential energy savings for connected and automated vehicle (CAV) control. The investigation began by establishing baseline and repeatability of energy consumption at various battery states of charge. It was determined that drive cycle energy consumption under a randomized set of boundary conditions varied within 3.6% of mean energy consumption regardless of initial battery state of charge. After completing 30 baseline drive cycles, a design for six sigma (DFSS) L18 array was designed to look at sensitivity of a range of parameters to energy consumption as related to connected and automated vehicles to target highest return on engineering development effort. The parameters explored in the DFSS array that showed the most sensitivity, in order of…
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Risk of Concussion in Low- to Moderate-Speed Frontal and Rear-End Motor Vehicle Collisions Evaluated Using Head Acceleration-Based Metrics

Exponent, Inc.-Stephanie A. Pasquesi, Alexander Bruno, Amy Courtney, Stacy M. Imler, Janine Smedley, Michael T. Prange
Published 2019-04-02 by SAE International in United States
Over the past decade, there has been an increase in awareness and concern about the occurrence and long-term effects of concussions. Traumatic brain injury (TBI)-related emergency department (ED) visits associated with motor vehicle collisions, including patients with a diagnosis of concussion or mild TBI (mTBI), have increased while deaths and hospital admissions related to TBI have decreased. The diagnostic criteria for concussion have evolved and broadened, and based on current assessments and diagnostic imaging techniques, there are often no objective findings, yet a diagnosis of concussion may still be rendered. Clinical assessment of concussion may be based only on patient-reported symptoms and history, making it difficult to objectively relate the reported increase in TBI-related ED visits due to motor vehicle collisions to specific collision parameters. This study aims to perform a scientific evaluation of concussion risk during motor vehicle collisions, strengthened by objective, quantitative data, specifically focusing on head acceleration-based metrics. Data from full-scale passenger vehicle crash tests are reported for frontal and rear-end collisions with delta-Vs ranging from 6.0 to 19.0 kph (3.7 to…
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Research on the Model of Safety Boundary Condition Based on Vehicle Intersection Conflict and Collision

Tongji University-Biao Wu, Xichan Zhu, Maozhu Liao, Rui Liu
Published 2019-04-02 by SAE International in United States
Because of the high frequency and serious consequences of traffic accidents in the intersection area, it is of great significance to study the vehicle conflict and collision scenarios of the intersection area. Due to few actual crash accidents occurring in naturalistic driving studies data or field operational tests data, the data of traffic accident database should be also used to analyze the intersection conflict and collision. According to the China Field Operation Test (China-FOT) database and the China in Depth Accident Study (CIDAS) database, the distribution feature of the respective intersection scenario type is obtained from the data analysis. Based on the intersection scenario type, two characters of intersection conflict and collision, the environmental character and the vehicle dynamic character, are used to analyze for the integration process of intersection conflict and collision. The environmental character contains several parameters, including environment type, weather and time, which has a strong influence on the collision accidents. Through the environmental parameters analyzing, the distribution model of environmental character is obtained. The vehicle dynamic character includes two vehicle dynamic…
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Thoracic Spine Extension Injuries in Occupants with Pre-Existing Conditions during Rear-End Collisions

Exponent, Inc.-Mathieu Davis, Jessica Isaacs, Martin Graber, Jacob Fisher
Published 2019-04-02 by SAE International in United States
Certain ankylosing spondyloarthropathies such as ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH) can substantially alter clinicopathologic spine biomechanics as well as injury mechanisms in rear-end motor vehicle collisions. AS is an inflammatory disease which can lead to structural impairments of the spine secondary to flowing ossification along the spinal column, including ossification across the spinal discs, facet joints, and ligaments, and it has also been associated with diffuse osteoporosis of the spine. DISH is characterized by excess bone formation along the spinal column, encompassing the annulus and forming the thickest and strongest bridging osteophytes over adjacent vertebral bodies at the level of the disc space. In both conditions the spine is mechanically stiffened and generally more kyphotic than a healthy spine. This paper presents a series of case studies in which a front-seat occupant with ankylosing spondyloarthropathy experienced a moderate- or high-speed rear-end collision and sustained a thoracic spine fracture/dislocation, often with spinal cord injuries. Forward acceleration of the occupant by the seat back in each case resulted in straightening of the kyphotic…
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