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Viewing 181 to 210 of 24128
2016-04-05
Technical Paper
2016-01-0993
Yoshinori Otsuki, Kenji Takeda, Hiroshi Nakamura
Abstract Recently, it was reported that the atmospheric pollution levels of nitrogen dioxide (NO2) and particulate matter (PM) are not decreasing despite the introduction of stricter vehicle emission regulations. The difference between conditions of the test cycles defined by the vehicle emission regulations and the real driving can contribute to the differences between expected and actual pollution levels. This has led to the introduction of in-use vehicle emission monitoring and regulations by means of a portable emission measurement system (PEMS). An optimized on-board PM analyzer was developed in this study. The on-board PM analyzer is a combination of a partial flow dilution system (PFDS) particulate sampler and a diffusion charger sensor (DCS) for real-time PM signals. The measuring technology and basic performance of the analyzer will be explained. Acceleration of the vehicle can cause uncertainty of flow measurement in the PM sampler.
2016-04-05
Technical Paper
2016-01-0045
Takanori Uno, Akahori Ichiro, Yoichiro Hara
Abstract In this paper, consideration is made to create a simulation model of the BCI test method, which is one of the EMC evaluation methods for in-vehicle electronic devices, and an intrinsic model of a BCI probe is provided. Using this model, it is demonstrated that when the impedance of the BCI probe is sufficiently high, the BCI probe serves as a transformer with a winding ratio of 1:1, and the admittance of a line or a load connected to each wire becomes proportional to the magnitude of current flowing in each wire. This model can also be applied when the leakage inductance inside the BCI probe is taken into consideration. The validity of this model is verified by experiment using a jig which can clamp multiple wires. In addition, by using this model, it is demonstrated that the S-parameters for dozens of wires clamped in the BCI probe can be generated using the S-parameter measurement results from when one wire is in the BCI probe.
2016-04-05
Journal Article
2016-01-0128
Philip Koopman, Michael Wagner
Abstract Software testing is all too often simply a bug hunt rather than a well-considered exercise in ensuring quality. A more methodical approach than a simple cycle of system-level test-fail-patch-test will be required to deploy safe autonomous vehicles at scale. The ISO 26262 development V process sets up a framework that ties each type of testing to a corresponding design or requirement document, but presents challenges when adapted to deal with the sorts of novel testing problems that face autonomous vehicles. This paper identifies five major challenge areas in testing according to the V model for autonomous vehicles: driver out of the loop, complex requirements, non-deterministic algorithms, inductive learning algorithms, and fail-operational systems.
2016-04-05
Technical Paper
2016-01-1277
Monis Alam, Ashish Jaiswal, Jatin Agarwal, Ketan Yadav, Naveen Kumar
Abstract Gasoline has been the major fuel in transportation, its good calorific value and high volatility have made it suitable for use in different injection methods. The drastic increase in use of carbon based fuels has led to increase in harmful emissions, thus resulting in implementation of stricter emissions norms. These harmful emissions include carbon monoxide and NOx. To meet the new norms and reduce the harmful emissions, better techniques have to be implemented to achieve better combustion of gasoline and reduce the amount of carbon monoxide in the exhaust. One such way of doing this is by enriching gasoline with hydrogen. Due to its low activation energy and high calorific value, the high energy released from hydrogen can be used to achieve complete combustion of gasoline fuel. However, there are certain drawbacks to the use of hydrogen in spark ignition engine, knocking and overheating of engine parts being the major problems.
2016-04-05
Technical Paper
2016-01-0273
Richard DeJong, Se Ge Jung, John Van Baren
Abstract Methods for conducting accelerated vibration fatigue testing of structures, such as MIL-STD-810G, allow for the non-linear scaling of the test time with the inverse of the rms vibration amplitude based on the slope of the material S-N curve obtained from cyclic fatigue tests. The Fatigue Damage Spectrum (FDS) is used as a method to allow for different level scalings at different frequencies in a broadband vibration environment using the relative responses of resonances in the structure. A recent development in industry has been to mix impulses with random excitations to increase the vibration peak levels (as measured by the kurtosis), thereby accelerating the fatigue even more than would occur with a Gaussian excitation. This paper presents results from a study to determine the conditions under which high kurtosis, impulsive excitations actually produce high kurtosis responses in structural resonances thus increasing the level of the FDS.
2016-04-05
Technical Paper
2016-01-0274
Sharon L. Honecker, David J. Groebel, Adamantios Mettas
Abstract In order to accurately predict product reliability, it is best to design a test in which many specimens are tested for a long duration. However, this scenario is not often practical due to economic and time constraints. This paper describes a reliability test in which a limited number of specimens are tested with little time remaining before the scheduled start of production. During the test, an unexpected failure mode that can be mitigated through a product redesign occurs. Because the scheduled start of production is near, there is not enough time to perform a test with redesigned specimens, so the current test proceeds as planned. We discuss several methods and the associated assumptions that must be made to account for the presence of the unexpected failure mode in the test data in order to make predictions of reliability of the redesigned product.
2016-04-05
Technical Paper
2016-01-0051
Hongyu Zheng, Mingxin Zhao
Abstract Electric power steering (EPS), active front wheel steering (AFS) and steer by wire systems (SBW) can enhance the handling stability and safety of the vehicle, even in dangerous working conditions. Now, the development of the electric control steering system (ECS) is mainly based on the way that combines the test of the electric steering hardware-in-loop (HIL) test bench with real vehicle tests. However, the real vehicle tests with higher cost, long cycle and vulnerable to space weather have the potential safety problems at early development. On contrast, electronic control steering HIL test bench can replace real vehicle tests under various working conditions and make previous preparations for real vehicle road tests, so as to reduce the number of real vehicle test, shorten the development cycle, lower development costs, which has gradually become the important link of research and development of electronic steering system.
2016-04-05
Technical Paper
2016-01-0272
Huairui Guo, David Dronzkowski
Abstract Pre-production vehicle validation is a critical step in understanding what potential issues end customers may find. Road profiles used in vehicle level tests are critical in finding failures. Clearly, if all the vehicles are tested only on highway, many failures will not be discovered. Therefore, using the right road profiles is very important. Traditionally, customer survey data is used to identify an appropriate road profile by defining a route that represents the Xth percentile customer. In this paper, a clustering method is applied to group all the customers into several groups. Each group is represented by a single road profile, and the entire customer population can be represented by multiple road profiles. If vehicles are tested using these profiles, then the road test can better represent the field condition, and hopefully failures can be discovered more efficiently.
2016-04-05
Technical Paper
2016-01-0417
Wan Xu, Xinfeng Shi, Tian Bai, Guobiao Yang, Lianxiang Yang, Changqing Du, Dajun Zhou, Yongjun Zhou
Abstract In Aluminum Alloy, AA, sheet metal forming, the through thickness cracking at the edge of cut out is one of the major fracture modes. In order to prevent the edge cracking in production forming process, practical edge stretch limit criteria are needed for virtual forming prediction and early stamping trial evaluations. This paper proposes new methods for determining the edge stretching limit of the sheet coupons, with and without pre-stretching, based on the Digital Image Correlation (DIC) technique. A numbers of sets of notch-shaped smaller coupons with three different pre-stretching conditions (near 5%, 10% and fractured) are cut from the prestretched large specimens. Then the notch-shaped smaller coupons are stretched by uniaxial tension up to through edge cracking observed. A dual-camera 3D-DIC system is utilized to measure both coupon face strain and thickness strain in the notch area at the same time.
2016-04-05
Technical Paper
2016-01-0419
Whitney Poling, Vesna Savic, Louis Hector, Anil Sachdev, Xiaohua Hu, Arun Devaraj, Fadi Abu-Farha
Abstract The strain-induced diffusionless shear transformation of retained austenite to martensite during straining of transformation induced plasticity (TRIP) assisted steels increases strain hardening and delays necking and fracture leading to exceptional ductility and strength, which are attractive for automotive applications. A novel technique that provides the retained austenite volume fraction variation with strain with improved precision is presented. Digital images of the gauge section of tensile specimens were first recorded up to selected plastic strains with a stereo digital image correlation (DIC) system. The austenite volume fraction was measured by synchrotron X-ray diffraction from small squares cut from the gage section. Strain fields in the squares were then computed by localizing the strain measurement to the corresponding region of a given square during DIC post-processing of the images recorded during tensile testing.
2016-04-05
Technical Paper
2016-01-0907
Matthew Blanks, Nathan Forster
Abstract In 2012, NHTSA and EPA extended Corporate Average Fuel Economy (CAFE) standards for light duty vehicles through the 2025 model year. The new standards require passenger cars to achieve an average of five percent annual improvement in fuel economy and light trucks to achieve three percent annual improvement. This regulatory requirement to improve fuel economy is driving research and development into fuel-saving technologies. A large portion of the current research is focused on incremental improvements in fuel economy through technologies such as new lubricant formulations. While these technologies typically yield less than two percent improvement, the gains are extremely significant and will play an increasing role in the overall effort to improve fuel economy. The ability to measure small, but statistically significant, changes in vehicle fuel economy is vital to the development of new technologies.
2016-04-05
Technical Paper
2016-01-0905
Robert J. Middleton, Omnaath Guptha Harihara Gupta, Han-Yuan Chang, George Lavoie, Jason Martz
Abstract This study evaluates the fuel economy implication of powertrain technologies capable of reducing light duty vehicle fuel consumption for compliance with 2025 CAFE standards. In a companion paper, a fully integrated GT-Power engine model was used to evaluate the effectiveness of one plausible series of engine technologies, including valve train improvements such as dual cam phasing and discrete variable valve lift, and engine downsizing with turbocharging and cooled EGR. In this paper, those engine efficiency/performance results are used in a vehicle drive cycle simulation to estimate the impact of engine and transmission technology improvements on light duty vehicle fuel consumption/economy over the EPA’s FTP and HWY test schedules. The model test vehicle is a midsized sedan based on the MY2012 Ford Fusion.
2016-04-05
Technical Paper
2016-01-1496
Richard R. Ruth, Brad Muir
Abstract Earlier research1 suggests there may be positive offset in the longitudinal G sensor in Toyota Corolla Gen 02 EDR’s. This research tests if a similar offset is present in Toyota Gen 04 EDR’s in the 2007 Yaris. A series of low speed forward and rearward collisions into a stationary vehicle were conducted. In addition to the installed vehicle ACM, additional identical “ride along” ACM’s were installed back to back, one front facing and one rear facing. The vehicle was also instrumented with a video VBOX to record speed at impact, and with the high precision “IST” accelerometer reference instrumentation. ACM’s facing toward the crash under-reported the negative longitudinal Delta V. After the initial impact was over, these forward facing ACM’s had a positive slope and at the end of the 200 ms recording were reporting a positive net Delta V, indicating a G sensor bias. The ACM’s facing away from the crash over reported the positive longitudinal Delta V.
2016-04-05
Technical Paper
2016-01-0105
Yogesh Chandra Sharma
Abstract This technical paper aims to provide a framework for simulating the thermal behavior of an automotive electrical connector with the current flow across each terminal. An automotive electrical connector uses multiple terminals fitted in the respective cavity of a connector. Temperature at terminal increases with the current flow level across it. This temperature rise occurs due to resistive heat loss in the terminal. Due to this, temperature in the surrounding cavities also rises; hence, the current carrying capacity of those cavities reduces. Analysis of similar scenarios for design alternatives and design decisions is important to develop reliable and optimized solutions. The reliable and optimized solution helps to save the cost. There is a large variation of different terminals used in the wiring harness, and there are various parameters attributing to this variation (shape, size, material, plating etc…).
2016-04-05
Technical Paper
2016-01-0099
Deepak Venkatesh, Arockia Selvakumar
Abstract The concept of camless engines enables us to optimize the overall engine efficiency and performance, as it provides great flexibility in valve timing and valve displacement. This paper deals with design of camless engines with pneumatic actuator. The main objective is to build a prototype and test its performance at different engine speeds. Also an extensive research on the sensors is done to detect the various sensors that could be used to identify the crankshaft position. Here the features and advantages over conventional engines are discussed. In addition the overview of the camless system in the engine is focused along with the design principle and the components used. The system thus designed is capable of actuating at 1500 rpm and demonstrates the ability of pneumatic actuators to be used in an internal combustion engine with low rpm needs.
2016-04-05
Journal Article
2016-01-1310
Yitian Zhang, David W. Herrin, T. Wu, Xin Hua
Abstract Prior research on assessing multiple inlet and outlet mufflers is limited, and only recently have researchers begun to consider suitable metrics for multiple inlet and outlet mufflers. In this paper, transmission loss and insertion loss are defined for multiple inlet and outlet mufflers using a superposition method that can be extended to any m-inlet n-outlet muffler. Transmission loss is determined assuming that the sources and terminations are anechoic. On the other hand, insertion loss considers reflections. For both metrics, the amplitude and phase relationship between the sources should be known a priori. This paper explains both metrics, and measurement of transmission and insertion loss are demonstrated for a 2-inlet 2-outlet muffler with good agreement.
2016-04-05
Technical Paper
2016-01-1559
Francesco Vinattieri, Tim Wright, Renzo Capitani, Claudio Annicchiarico, Giacomo Danisi
Abstract The adoption of Electrical Power Steering (EPS) systems has greatly opened up the possibilities to control the steering wheel torque, which is a critical parameter in the subjective and objective evaluation of a new vehicle. Therefore, the tuning of the EPS controller is not only becoming increasing complicated, containing dozens of parameters and maps, but it is crucial in defining the basic DNA of the steering feeling characteristics. The largely subjective nature of the steering feeling assessment means that EPS tuning consists primarily of subjective tests on running prototypes. On account of that, this paper presents an alternative test bench for steering feeling simulation and evaluation. It combines a static driving simulator with a physical EPS assisted steering rack. The end goal is to more accurately reproduce the tactile feedback to the driver by including a physical hardware in lieu of complicated and difficult to obtain software models.
2016-04-05
Technical Paper
2016-01-1573
Ken Archibald, Kyle Archibald, Donald Neubauer
Abstract This paper will document a rationale for wheel straightening based on the rise of declining roads, increased consumer preference for lower profile tires, unintended consequences of wheel customization and the reduction in energy consumption. A recommended patented procedure detailing how A356-T6 wheels can be straightened will be presented. To validate the recommended procedure a sample of wheels was uniformly deformed and straightened and subsequently tested per SAE J328 and SAE J175. Test results are provided that indicate straightened wheels should be fully serviceable in their intended service. A laboratory protocol to replicate the wheel flange cracks is described. The protocol is used to demonstrate that wheels without deformations do not result in flange cracks. Conversely wheels with deformations in excess of 1.5mm do result in cracks at less than 750,000 cycles.
2016-04-05
Journal Article
2016-01-0578
Giuseppe Cicalese, Fabio Berni, Stefano Fontanesi
Abstract New SI engine generations are characterized by a simultaneous reduction of the engine displacement and an increase of the brake power; such targets are achieved through the adoption of several techniques such as turbocharging, direct fuel injection, variable valve timing and variable port lengths. This design approach, called “downsizing”, leads to a marked increase in the thermal loads acting on the engine components, in particular on those facing the combustion chamber. Hence, an accurate evaluation of the thermal field is of primary importance in order to avoid mechanical failures. Moreover, the correct evaluation of the temperature distribution improves the prediction of pointwise abnormal combustion onset.
2016-04-05
Journal Article
2016-01-0959
Dhinesh Kumar, Ashwhanth Raju, Nitin Sheth, Steffen Digeser
Abstract The future emission regulation (BS V) in India is expected to create new challenges to meet the particulate matter (PM) limit for diesel cars. The upcoming emission norms will bring down the limit of PM by 80 % when compared to BS IV emission norms. The diesel particulate filter (DPF) is one of the promising technologies to achieve this emission target. The implementation of DPF system into Indian market poses challenges against fuel quality, driving cycles and warranty. Hence, it is necessary to do a detailed on-road evaluation of the DPF system with commercially available fuel under country specific drive cycles. Therefore, we conducted full vehicle durability testing with DPF system which is available in the European market to evaluate its robustness and reliability with BS III fuel (≤350ppm sulfur) & BS IV (≤50ppm sulfur) fuel under real Indian driving conditions.
2016-04-05
Technical Paper
2016-01-1545
Huan Liu, Guoying Chen, Changfu Zong
Abstract A new electric power steering system (EPS) dynamic friction model based on normalized Bouc-Wen model is given, as well as its structure form and model features. In addition, experimental method is used to identify corresponding parameters. In order to improve road feel feedback, this paper analyzes the shortcoming of traditional constant friction compensation control method and proposes a variable friction compensation control method which the friction compensation current changes according to the assist characteristic gain. Through simulation and real vehicle test verification, variable friction compensation control method eliminates the effect of basic assist characteristic, and improves the driver’s road feel under high speed.
2016-04-05
Technical Paper
2016-01-0270
Zhigang Wei, Limin Luo, Michael Start, Litang Gao
Product validation and reliability demonstration require testing of limited samples and probabilistic analyses of the test data. The uncertainties introduced from the tests with limited sample sizes and the assumptions made about the underlying probabilistic distribution will significantly impact the results and the results interpretation. Therefore, understanding the nature of these uncertainties is critical to test method development, uncertainty reduction, data interpretation, and the effectiveness of the validation and reliability demonstration procedures. In this paper, these uncertainties are investigated with the focuses on the following two aspects: (1) fundamentals of the RxxCyy criterion used in both the life testing and the binomial testing methods, (2) issues and benefits of using the two-parameter Weibull probabilistic distribution function.
2016-04-05
Technical Paper
2016-01-1600
Pruthviraj Mohanrao Palaskar, Vivek Kumar, Rohit Vaidya
Abstract Important vehicle performance parameters such as, fuel economy and high speed stability are directly influenced by its aerodynamic drag and lift. Wind tunnel testing to asses these parameters requires heavy investment especially when test wind tunnel is not available in the country where vehicle development center is present. Hence to save cost and to compress development time, it is essential to asses and optimize parameters of a vehicle in very early stages of development. Using numerical flow simulations optimization runs can be carried out digitally. Industry demands prediction of aerodynamic drag and lift coefficients (CD,CL) within an accuracy of a few counts, consuming minimal HPC resources and in a short turnaround time. Different OEMs deploy different testing methods and different softwares for numerical simulations.
2016-04-05
Technical Paper
2016-01-0429
Paul Augustine, Timothy Hunter, Nathan Sievers, Xiaoru Guo
Abstract The performance of a structural design significantly depends upon the assumptions made on input load. In order to estimate the input load, during the design and development stage of the suspension assembly of a BAJA car, designers and analysts invest immense amount of time and effort to formulate the mathematical model of the design. These theoretical formulations may include idealization errors which can affect the performance of the car as a final product. Due to the errors associated with the assumption of design load, several components might have more weight or may have less strength than needed. This discrepancy between the assumed input load (lab or theoretical studies) and the actual load from the environment can be eliminated by performing a real life testing process using load recovery methodology. Commercial load cells exist in industry to give engineers insight to understanding the complex real world loading of their structures.
2016-04-05
Journal Article
2016-01-0049
Jinwei Zhou, Roman Schmied, Alexander Sandalek, Helmut Kokal, Luigi del Re
Abstract Virtual testing of advanced driver assistance systems (ADAS) using a simulation environment provides great potential in reducing real world testing and therefore currently much effort is spent on the development of such tools. This work proposes a simulation and hardware-in-the-loop (HIL) framework, which helps to create a virtual test environment for ADAS based on real world test drive. The idea is to reproduce environmental conditions obtained on a test drive within a simulation environment. For this purpose, a production standard BMW 320d is equipped with a radar sensor to capture surrounding traffic objects and used as vehicle for test drives. Post processing of recorded GPS raw data from the navigation system using an open source map service and the radar data allows an exact reproduction of the driven road including other traffic participants.
2016-04-05
Technical Paper
2016-01-0053
Abhishek Sharma
Abstract Today open source software is widely used in different domains like Desktop systems, Consumer electronics (smart phones, TV, washing machines, camera, printers, smart watches), Automotive, Automation etc. With the increased involvement of the open source software in the different domains including the safety critical ones, there has been a requirement of the well-defined test strategy to test and verify such systems. Currently there are multiple open source tools and frameworks to choose from. The paper describes the various open source test strategies and tools available to qualify such systems, their features, maintenance, community support, advantages and disadvantages. Target audience would be the software engineers, program managers, using an open source stack for the product development.
2016-04-05
Journal Article
2016-01-0050
Huafeng Yu, Chung-Wei Lin, BaekGyu Kim
Abstract Modern vehicles can have millions of lines of software, for vehicle control, infotainment, etc. The correctness and quality of the software play a key role in the safety of whole vehicles. In order to assure the safety, engineers give an effort to prove correctness of individual subsystems or their integration using testing or verification methods. One needs to eventually certify that the developed vehicle as a whole is indeed safe using the artifacts and evidences produced throughout the development cycle. Such a certification process helps to increase the safety confidence of the developed software and reduce OEM’s liability. However, software certification in automotive domain is not yet well established, compared to other safety-critical domains, such as avionics and medical devices. At the same time, safety-relevant standards and techniques, including ISO 26262 and assurance cases, have been well adopted.
2016-04-05
Technical Paper
2016-01-1007
Benjamin Ellies, Charles Schenk, Paul Dekraker
Abstract As part of its technology assessment for the upcoming midterm evaluation (MTE) of the 2022-2025 Light-Duty Vehicle Greenhouse Gas (LD GHG) emissions standards, EPA has been benchmarking engines and transmissions to generate inputs for use in its Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) model, a physics-based, forward-looking, full vehicle computer simulation tool. One of the most efficient engines today, a 2.0L Mazda SkyActiv engine, is of particular interest due to its high geometric compression ratio and use of an Atkinson cycle. EPA benchmarked the 2.0L SkyActiv at its National Vehicle and Fuel Emissions laboratory. EPA then incorporated ALPHA into an engine dynamometer control system so that vehicle chassis testing could be simulated with a hardware-in-the-loop (HIL) approach.
2016-04-05
Technical Paper
2016-01-0029
Chuanliangzi Liu, Bo Chen, Ming Cheng, Anthony Champagne, Keyur Patel
Abstract The Electronic Control Unit (ECU) of an Electric Power Steering (EPS) system is a core device to decide how much assistance an electric motor applies on a steering wheel. The EPS ECU plays an important role in EPS systems. The effectiveness of an ECU needs to be thoroughly tested before mass production. Hardware-in-the-loop simulation provides an efficient way for the development and testing of embedded controllers. This paper focuses on the development of a HiL system for testing EPS controllers. The hardware of the HiL system employs a dSPACE HiL simulator. The EPS plant model is an integrated model consisting of a Vehicle Dynamics model of the dSPACE Automotive Simulation Model (ASM) and the Nexteer Steering model. The paper presents the design of an EPS HiL system, the simulation of sensors and actuators, the functions of the ASM Vehicle Dynamics model, and the integration method of the ASM Vehicle Dynamics model with a Steering model.
2016-04-05
Technical Paper
2016-01-0575
Konstantinos Siokos, Rohit Koli, Robert Prucka, Jason Schwanke, Shyam Jade
Abstract Low pressure (LP) and cooled EGR systems are capable of increasing fuel efficiency of turbocharged gasoline engines, however they introduce control challenges. Accurate exhaust pressure modeling is of particular importance for real-time feedforward control of these EGR systems since they operate under low pressure differentials. To provide a solution that does not depend on physical sensors in the exhaust and also does not require extensive calibration, a coupled temperature and pressure physics-based model is proposed. The exhaust pipe is split into two different lumped sections based on flow conditions in order to calculate turbine-outlet pressure, which is the driving force for LP-EGR. The temperature model uses the turbine-outlet temperature as an input, which is known through existing engine control models, to determine heat transfer losses through the exhaust.
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