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Viewing 1 to 30 of 2764
2011-04-12
Technical Paper
2011-01-0457
Yixin Chen, Jeffrey Pfeiffer, Ken Simpson
This paper first presents a basic mean value engine plant model implemented in a hardware-in-the-loop (HIL) system. The plant model includes some basic engine parameters such as engine speed, manifold absolute pressure, etc., which are critical to both control algorithm integrity and default actions that result from improper signal performance (e.g., ECU shuts down due to corrupted signal(s)). The model is then improved to develop the HIL bench-based testing capabilities in the areas where a vehicle has traditionally been required. The on-board diagnostic monitor tests covered by SID $06 of SAE J1979 are selected as a case study. Specifically, for OBD exhaust gas sensor monitor testing purposes, the oxygen sensor model is developed to simulate normal or abnormal binary switching signals which might have asymmetric “lean to rich” and “rich to lean” transitions, or largely off maximum/minimum sensor voltages, etc.
2011-04-12
Technical Paper
2011-01-0454
Matt Rings, Paul Phillips
The increase in the number of electronic control units (ECUs) in the modern vehicle, combined with increased software complexity and more distributed controls has led to an extreme testing challenge when it comes to the verification and validation of body-control ECUs. In general test engineers have to deal with more software configurations, more closed-loop interaction between ECUs, and more fault conditions than ever before. By adding Unified Diagnostic Services (UDS) over CAN to a Hardware-In-The-Loop (HIL) test system, Lear was able to increase test automation and provide wider test coverage by automating the ECU flashing process, adding diagnostic identifiers and trouble codes to their test scripts, and providing a quick and easy way to exercise ECU I/O. Lear chose to implement their HIL testers on the open PXI[1] hardware platform, utilizing National Instruments' VeriStand software framework.
2011-04-12
Technical Paper
2011-01-0451
Florian Schmidt
Advanced Driver Assistance Systems (ADAS) in modern cars contain actively reacting functionality, like autonomous steering or braking assistants. The demand for functional Hardware-in-the-Loop (HiL) testing of these systems contains the need to create realistic models of the car's surrounding. Generating high-resolution photorealistic 3D-graphics in real-time proved to be critical, but with modern graphics technology, “Visual Loop” test-systems can be built. Integrated into test processes and with automated test case generation, these testing tools can improve the performance and quality of functional verification and validation significantly.
2011-04-12
Technical Paper
2011-01-0231
YoungJae Jung, Yeongwoo Yoo
In recent years, many automotive companies have been striving to reduce costs and shorten new vehicle development cycle time. To develop a new vehicle costs a tremendous amount especially at the prototype phase. So currently vehicle simulation on the powertrain bench is an attractive alternative at the development phase to reduce the quantity of proto vehicles. This test method moves the test site from the road to the bench without the need for real chassis parts. This paper deals with the method and strategy for moving testing from road to bench, specifically emission and fuel economy test for vehicles equipped with manual transmission. To execute vehicle type tests on the bench requires correlation and simulation of many parameters - for example gear shifting, throttle position, clutch travel and related driver characteristics, temperature and driving road load resistance, etc.
2011-04-12
Journal Article
2011-01-0227
Sebastian Kunkel, Martin Werner, Georg Wachtmeister
This SAE Technical Paper gives a summary of the essential findings in the development and operation of a test engine dedicated to the measuring of the friction between the piston group and the liner. Firstly the fundamental demands on the high-precision and close to real engine operation friction measuring are laid out. Subsequently the basic engine, the measuring system based on the floating liner method including a gas balance device, as well as the implemented measuring technique are specified. Major influencing variables on the friction of the piston assembly and its interference variables are also summarized. Extensive information about the systematic and strategies for the test engine's operation startup are given in acknowledgement of influencing and interference variables. This strategy reduces the developmental and startup process of an engine dedicated to the measuring of piston group friction.
2011-04-12
Technical Paper
2011-01-0225
Sam Scime
For decades, the industry standard for laboratory durability simulations has been based on reproducing quantified vehicle responses. That is, build a running vehicle, measure its responses over a variety of durability road surfaces and reproduce those responses in the laboratory for durability evaluation. To bring a vehicle to market quickly, the time between tightening the last bolt on a prototype test vehicle and starting the durability evaluation test must be minimized. A method to derive 4-Post simulator displacements without measuring or predicting vehicle responses is presented.
2011-04-12
Technical Paper
2011-01-0161
Tsuneaki Ishima, Yasushi Takahashi, Haruki Okado, Yasukazu Baba, Tomio Obokata
In CFD (Computational Fluid Dynamics) verification of vehicle aerodynamics, detailed velocity measurements are required. The conventional 2D-PIV (Two Dimensional Particle Image Velocimetry) needs at least twice the number of operations to measure the three components of velocity ( u,v,w ), thus it is difficult to set up precise measurement positions. Furthermore, there are some areas where measurements are rendered impossible due to the relative position of the object and the optical system. That is why the acquisition of detailed velocity data around a vehicle has not yet been attained. In this study, a detailed velocity measurement was conducted using a 3D-PIV measurement system. The measurement target was a quarter scale SAE standard vehicle model. The wind tunnel system which was also designed for a quarter scale car model was utilized. It consisted of a moving belt and a boundary suction system.
2011-04-12
Journal Article
2011-01-0484
Andrew Halfpenny, Mark Pompetzki
Proving grounds are an extremely efficient means of qualifying the durability of vehicle components. They accelerate damage accumulation rates so failures are detectable in a very short period of time. It is important that proving ground damage is correlated with target customer usage. It is also important to determine the most efficient use of the proving ground in order to meet project targets and minimize overall development costs. This paper describes the latest techniques for proving ground correlation and optimization. Acceleration, strain, wheel force and other types of data are collected on a vehicle as it traverses different proving ground surfaces. Comparable data are also collected from instrumented ‘customer’ vehicles. The objective of the analysis is to determine which mixture of proving ground surfaces offers the best representation of customer usage while minimizing the total test time.
2011-04-12
Technical Paper
2011-01-0490
Sharvin Motamedi, John Dennis, Ted T. Stawiarski, A.K. Khosrovaneh, Li L. Sun, Mohamed El-Sayed
Large hood mounted plastic trim components are subjected to complex and often extreme loading conditions. Typical loading conditions include solar and thermal cycling, as well as road and powertrain induced vibrations, aero lift and buffeting, and mechanical loads such as car wash. For the above components understanding and classifying the typical loading conditions is an essential and important step in achieving long term quality. This paper discusses different approaches to the design, analysis, development, and testing of plastic trim components. Samples of analysis and test results are presented to demonstrate how to identify and prevent the loss of the part function. Some useful guidelines and practices for addressing thermal expansion, dimensional variation, and redundancy in attachments are also discussed.
2013-05-13
Journal Article
2013-01-1962
Robert Otto Rasmussen
Pavements complying with the ISO 10844 standard are an important component of vehicle and tire noise testing. In 2011, a new version of this standard was published, which includes many important changes compared to the 1994 version. As a result, some tracks that complied with the 1994 standard are now nonconforming with the 2011 version. Many tracks are in the process of being resurfaced, particularly before regulations are adopted that require conformance with the new version of the standard. While repaving is costly, it can also lead to opportunity. Pavement engineering encompasses pavement design, materials selection and proportioning, and the selection of construction techniques. Pavement life is also an important engineering criterion. In the case of test tracks, life is most often defined by functional performance including changes in friction, rolling resistance, ride, and in this instance, noise.
2013-05-13
Technical Paper
2013-01-1968
Daniel Fernandez Comesana, Branko Zjamsek, Andrea Grosso, Keith Holland
Exterior noise testing is one of the main standardized quality controls required for developing the majority of vehicles. The combination of static tests and on-road measurements provides an essential key to undertaking a successful refinement process. Beamforming techniques using phased microphone arrays are one of the most common tools for localizing and quantifying noise sources across the vehicle body. However, the use of such devices can result in a series of well-known disadvantages regarding, for instance, their very high cost or transducer calibration problems. Virtual Phased Arrays (VPAs) are proposed as an alternative solution to prevent these difficulties providing the sound field is time stationary. Several frequency domain beamforming techniques can be adapted to only use the relative phase between a fixed and a moving transducer.
2013-05-13
Journal Article
2013-01-1970
Roland Sottek, Bernd Philippen
In a vehicle's development process, Transfer Path Analysis (TPA) is commonly used for identifying sound sources and their transmission to a receiver. Forces acting on the structure are the reason for the structure-borne sound share of the vehicle interior noise. In practice it is not possible, or too extensive, to measure operational forces directly. Instead, they are often calculated indirectly from accelerations and from additionally measured inertances. As the car body is a strongly coupled system, a force acting at one position results in accelerations throughout the structure. This crosstalk must be considered by using a dense inertance matrix consisting of the ratios between each force excitation and the accelerations at every sensor position. Then a matrix inversion is performed to solve the system of equations describing the coupling of the structure.
2013-05-13
Technical Paper
2013-01-1965
X. Hua, D. W. Herrin
The measurement of sound absorption coefficient (SAC) of porous materials is covered by both American and international standards. However, by using the standards alone it is difficult to achieve consistently repeatable results given the large number of variables such as sample cutting and preparation, sample fit and position in the tube, and sample material variability. This paper will review the standards briefly and examine what is available in the literature to guide users in making consistently repeatable SAC measurements. The paper will also show some of the authors' results and interpret these results in light of the standards and technical literature on the subject.
2013-05-13
Technical Paper
2013-01-1978
Seung Min Lee, Taejin Shin, ByungHyun Kim, Sang Kwon Lee
In this paper, the sound intensity and airborne source quantification methods were used to estimate the airborne noise radiating from a gasoline direction injection engine and the contribution of gasoline direction injection engine components to such airborne noise. In order to estimate noise contribution using airborne source quantification, the volume velocity for source should be estimated. In the previous method, the volume velocity has been estimated by using the inverse method. In this paper, the volume velocity is estimated directly. For this work, the sources of noise radiating from the engine are first identified by measuring the sound intensity of the noise sources while the car's engine is running at idle condition. The volume velocities of these sources estimated by multiplying the area of that noise source and directly measured particle velocity.
2013-05-13
Journal Article
2013-01-1977
Jorgen Hald
Beamforming with an array of microphones on a sphere is an attractive tool for doing noise source localization in cabin environments. In order to achieve acceptable angular resolution, the array must have some minimum diameter, implying that many microphones are needed to obtain low sidelobe level over the frequency range of interest. For electric cars there is an increased need to cover high frequencies. The present paper describes a method to significantly reduce the sidelobe level over a broad frequency range relative to Spherical Harmonics Beamforming (SHB). For each focus point, a set of Finite Impulse Response (FIR) filters are optimized to minimize the highest sidelobe in a Filter And Sum (FAS) beamformer, while maintaining sensitivity at the focus point and limiting the White Noise Gain (WNG).
2013-05-13
Technical Paper
2013-01-2008
Steven Jorro, John Zehme, Sam Mleczko, Eglind Myftiu, Blake Rager
The reduction of full acceleration truck pass-by noise conforming to Type ECE-51 regulation (Reference 1) was predicted in a hemi-anechoic chassis dynamometer chamber with microphone arrays and compared with actual test track results. This gave a close match to the track data, with both showing a 4 dB reduction in the A-weighted overall noise level after identical acoustic treatments were applied. Noise control materials were selected to perform as acoustic barriers and absorbers. These were optimized by analyzing the 1/3 octave spectra, determining dominant frequency bands, in critical source locations and engine speeds, and using combinations that dissipate or contain energy well within those bands. With the truck being stationary while tested, important source locations could be quickly identified both subjectively and with localization tools such as Beamforming.
2013-04-08
Journal Article
2013-01-0891
Sumit Khadilkar, Ahmed Soliman, Peter Schuetzbach, Marko Kustic
Filtration of diesel and gasoline fuel in automotive applications is affected by many external and internal parameters, e.g. vibration, temperature, pressure, flow pulsation, and engine start-stop. Current test procedures for automotive fuel filters, proposed by most of the researchers and organizations including Society for Automotive Engineers (SAE) and International Organization for Standardization (ISO), do not apply the previously mentioned real-world-conditions. These operating conditions, which are typical for an automotive fueling system, have a significant effect on fuel filtration and need to be considered for the accurate assessment of the filter. This requires the development of improved testing procedures that will simulate the operating conditions in a fuel system as encountered in the real world.
2013-04-08
Journal Article
2013-01-1218
Saikrishna Sundararaman
One of the commonly used methods for evaluating friction and wear behavior of hard plastics is described in ASTM 3702 test specification. Wear tests conducted using this test method show that friction coefficient is dependent on temperature (generated due to friction), especially for filled plastics. Tests with high load and / or speed result in melting of the plastic due to excessive temperature build up. In the present study, a method has been developed to conduct dry and lubricated wear tests while controlling test temperature. Controlling temperature ensures that the failure mode of the test specimen is due to wear and not due to melting resulting from excessive temperature build up. The details of temperature control for both dry and lubricated wear tests are outlined and wear rate / friction for different combinations of loads and speeds are presented.
2013-04-08
Journal Article
2013-01-1230
Steffen Ostendorff, Joerg Sachsse, Heinz-Dietrich Wuttke, Jorge Meza Escobar
This paper presents an adaptive test approach to improve the structural testing of printed circuit boards (PCB) found in electronic automotive components. The approach makes use of FPGAs available on the PCBs, and its applicability is supported by the global trend taking place in the automotive industry of replacing ASICs with programmable devices such as FPGAs. For structural testing of PCBs, Boundary Scan (BScan) is mostly used. However, BScan has the disadvantage of being a static test method due to the slow execution speed reducing the fault coverage concerning dynamic faults. FPGAs support BScan as well, but they also offer a vast number of programmable resources. These resources can be configured for testing purposes. Our approach is to speed-up the testing process during the PCB manufacturing by moving data intensive processing from the external software side (Test-PC) to the programmable hardware side on-board (FPGA), reducing the data transfer over the slow JTAG interface.
2013-04-08
Journal Article
2013-01-1228
Graciela Becci, Gunwant Dhadyalla, Alexandros Mouzakitis, James Marco, Andrew David Moore
Testing real-time vehicular systems challenges the tester to design test cases for concurrent and sequential input events, emulating unexpected user and usage profiles. The vehicle response should be robust to unexpected user actions. Sequence Covering Arrays (SCA) offer an approach which can emulate such unexpected user actions by generating an optimized set of test vectors which cover all possible t-way sequences of events. The objective of this research was to find an efficient nonfunctional sequence testing (NFST) strategy for testing the robustness of real-time automotive embedded systems measured by their ability to recover (prove-out test) after applying sequences of user and usage patterns generated by combinatorial test algorithms, considered as “noisy” inputs. The method was validated with a case study of an automotive embedded system tested at Hardware-In-the-Loop (HIL) level. The random sequences were able to alter the system functionality observed at the prove-out test.
2013-09-08
Technical Paper
2013-24-0180
Thomas Stanger, Richard Viskup, Luigi del Re, Alexander Bergmann, Tristan Reinisch
Measurements of transient emissions become more important due to the increasing contribution of transient operation to the total tail pipe emissions. While for many quantities measurement devices with response time in the range of few milliseconds exist, the same is not true for particulate matter(PM). Pulsed Laser Induced Incandescence (LII) is widely used in experimental setups and may offer a viable approach also for production engines, but the specific nature of LII raises doubts on the quantitative precision achievable by the method, especially in transient operation. Indeed, there are two main problems in particular for dynamic measurements. On one side, the emitted laser power must be high enough to excite a sufficiently large number of particles within the observed area, but not as high to destroy them, and varying engine operating conditions imply changes in the number and size distribution of the particles as well.
2013-09-30
Technical Paper
2013-01-2071
Carlos Agudelo, Raleigh Belcher, Dhawal Dharaiya
This paper presents three main topics which proved useful during the systematic resolution and testing program to confirm the ability of the proposed friction material to conform to the performance requirements indicated on the TP-121D [1] dynamometer test. Initially, the paper presents some commonalities and differences between the vehicle FMVSS 121[2], the dynamometer TP-121D and the SAE J2115-06 [3] test protocols. The second part of the paper elaborates on the implementation of the methodology established on the ASTM E1169-07 [4]. This standard relies on Design of Experiments (DOE) methods to assess the robustness of a given test method when testing on the extreme values allowed for key test conditions. The DOE used a three-factor, two-level, fractional factorial design to investigate the influence of (a) cooling air speed, (b) brake power as the combination of test inertia and deceleration settings, and (c) brake adjustment method.
2004-03-08
Technical Paper
2004-01-0133
Wenyue Zheng, C. Derushie, R. Zhang, J. Lo
Magnesium alloys, with the highest strength-to-weight ratio of the common engineering alloys, have been used in castings of various automotive components. The forecast trend for the use of the metal in automobiles suggests a more rapid growth pace in the coming decade. However, Mg alloys happen to be among the most reactive materials in natural environments, such as those applicable to the exterior automotive conditions. The most challenging form of corrosion is galvanic corrosion: the corrosion of Mg parts when in contact with other materials such as coated steel bolts and nuts. In the joining areas, crevice corrosion can also be a concern. Effective coatings are essential for such applications.
2004-03-08
Technical Paper
2004-01-0137
S. E. LeBeau, M. W. Walukas, R. F. Decker, Pierre LaBelle, A. R. Moore, J. W. Jones
Automotive manufacturers are continually pushing for reduced cost, increased fuel economy, lower emissions and improved performance. Magnesium is the lightest structural metal and has therefore enjoyed a double-digit annual growth in automotive applications since 1990, aimed at reducing vehicle platform weights to increase fuel economy. Nevertheless the progress of magnesium as an alternative lightweight structural material (compared to aluminum, engineered plastics and high alloy steels) is being impeded by the lack of published alloy properties and general knowledge of the material. Thixomat, Inc. is conducting independent fundamental studies to measure the influence of Thixomolding® process parameters on a variety of physical and mechanical properties for injection molded magnesium alloys. Determination of conventional mechanical properties are being complemented with fatigue behavior studies using new ultrasonic fatigue instrumentation at the University of Michigan.
2004-03-08
Technical Paper
2004-01-0144
Houliang Li, Robin Soon, Xiaoming Bian, Joseph Lanzesira, Pamela Dawson, Richard Beason
There are benefits of using ultra thin wall (UTW) substrates (i.e., 900/2, 400/4, etc) in lowering cost and emission level. However, the more fragile mechanical characteristics of the UTW present a challenge to design and manufacture of robust catalytic converters. This paper describes a method of canning trial, where a combined Design of Experiment / Monte-Carlo analysis method was used, to develop and validate a canning method for ultra thin wall substrates. Canning trials were conducted in two stages-- Prototype Canning Trial and Production Canning Trial. In Prototype Canning Trial, the root cause of substrate failure was identified and a model for predicting substrate failure was established. Key factors affecting scrap rate and gap capability were identified and predictions were performed on scrap rate and gap capability with the allowed variations in the key factors. The results provided guidelines in designing production line and process control.
2004-03-08
Technical Paper
2004-01-0147
H. Sumida, Y. Koda, A. Sadai, S. Ichikawa, M. Kyogoku, M. Takato, Y. Miwa, R.W. McCabe
Phosphorous poisoning on customer-aged catalysts was investigated by material analysis and performance testing. Most of the phosphorus was associated with the oxide components in the washcoat. These contaminants were roughly classified as aluminum phosphate, cerium phosphate, zinc-calcium phosphate. Deactivation of the catalyst with aluminum phosphate was strong and followed a linear correlation from oxalic acid testing. Phosphorus scavenging additives were researched to inhibit increase of aluminum phosphate. According to thermodynamic calculations, lower free energy of compounds of additive and phosphate is expected to prevent formation of aluminum phosphate.
2004-03-08
Technical Paper
2004-01-0146
Nathan Brunner
While emission standards require greatly reduced levels of certain vehicle emissions, additional regulations require those levels to be met for the useful life of the vehicle, currently specified as 10 years / 100,000 miles for light duty vehicles1. As vehicle manufacturers anticipate requirements of 15 years / 150,000 miles, converter performance and durability must be predicted further into the future. The realities of the world market and competitive pressures require greatly improved test methods to establish converter robustness well in advance of the start of production. Such methods must enable robustness assessment in a compressed timeframe and at low cost. Often, a converter concept must be evaluated well before the first prototype engine or vehicle is assembled. To address these needs, a new approach to converter package durability was conceived by an industry group whose members shared the goal of early converter life prediction.
2004-03-08
Technical Paper
2004-01-0351
Burak A. Gecim
Efficiency of a toroidal traction drive is measured at different torques, speeds, speed ratios, and temperatures, with an emphasis on the effect of the design traction coefficient on variator efficiency. This is accomplished by independently controlling the trunnion and the clamp pressures representing the variator torque and the clamp load, respectively. Also measured is the effect of roller conformity on variator efficiency. Furthermore, a low-speed and high-temperature test is conducted to observe a potential change in the effective coefficient of traction due to a transition in the lubrication mode. It is shown that, by optimum clamping (without gross slip) the variator efficiency can be increased by 1- to 2-percentage point over the efficiencies measured with nominal clamp loads. Also verified is the rapid decrease in variator efficiency with over clamping above the nominal clamp loads. All test results compared well with model predictions.
2004-03-08
Technical Paper
2004-01-0395
Venkatesh Kannan, John Seifert, Tony Golletti, Dave Hanner
An intake manifold produced a distinct whistle noise in a vehicle while driving through high torque conditions. The diagnostic tests in a steady air flow test bench helped reveal that the whistle was occurring due to the shear layer instabilities in the air flow over the sump cavity in the intake manifold which acts as an Helmoltz-like resonator. Joint time-frequency domain signal analysis was applied to detect the peak whistle. A sharp radius and a ramp at the upstream edge of the sump cavity reduced the peak whistle sound pressure level from 106dB to 85dB in the air flow bench and made the whistle inaudible in the vehicle. Tolerance study was performed on this geometry to allow manufacturing variations. A test method, using rapid prototype parts, has been developed in order to identify whistles early in the design cycle.
2004-03-08
Technical Paper
2004-01-1506
Chris Swales, Christoph Capellmann, Matt Crompton, Marcus Matthes
Customer clinics and surveys have revealed the increased importance to the customer of good defrost and demist performance in their vehicle. Achieving this level of performance, within the time and cost constraints of a modern vehicle development program, places increased reliance on computational (CAE) techniques. However, this paper describes how the optimum development process should be to combine this reliance upon CAE methods with a newly developed experimental technique. This new laser Doppler velocimetry (LDV) based methodology is employed at all stages of the development process and complements the CAE techniques perfectly. The end result is optimized airflow management within the vehicle cabin – essential if good defrost and demist performance is to be achieved in a vehicle.
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