Display:

Results

Viewing 61 to 90 of 23980
2016-04-05
Technical Paper
2016-01-1072
Peter Schaal, Byron Mason, Sotiris Filippou, Ioannis souflas, Mark Cary
The paper presents a measurement methodology which combines an ultra-fast thermocouple with an input reconstruction technique in order to measure crank angle resolved temperature phenomena in an engine air-intake system. Thermocouples that are of practical use in engine experiments tend to have a large time constant which affects measurement accuracy during rapid temperature transients. Input reconstruction methods have previously been applied for use on larger diameter thermocouples but have not been applied to ultra-thin uninsulated wire thermocouples to investigate cyclic intake temperature behaviour. Accurate measurement results are of interest to improve the validity of many crank-angle resolved engine models. An unshielded thermocouple sensor has been developed which is rigid enough to withstand the aerodynamic forces of the intake air.
2016-04-05
Technical Paper
2016-01-0646
Pablo Olmeda, Jaime Martin, Antonio Garcia, Diego Blanco, Alok Warey, Vicent Domenech
Regulated emissions and fuel consumption are the main constraints affecting engine design. Over the years, many techniques have been used with the aim of meeting these limitations. In particular, EGR has demonstrated to be a necessary solution to reduce NOx emissions, becoming a widely used technique in production diesel engines. However, its application has a direct effect on fuel consumption due to both the changes in the in-cylinder processes, affecting indicated efficiency, as well as air management. An analysis, based on the engine Global Energy Balance, is presented to thoroughly assess the behavior of a HSDI diesel engine under variable EGR conditions at different operating points. The tests have been carried out, while keeping combustion phasing and conditions at intake valve closing (IVC) fixed.
2016-04-05
Technical Paper
2016-01-1365
Siddharth Bhupendra Unadkat, Suhas Kangde, Mahalingesh Burkul, Mahesh Badireddy
The overall automotive industry is moving toward first time right test which in turn needs first time right analysis. This is due to the enormous pressure of cost, mass, time to market and availability of prototype vehicles for testing. Use of finite element methods enables to upfront predict the system behavior in operating conditions and evaluation of structural strength. In vehicle product development process, hood slam durability evaluation is one of the important test for body closure structure. Current work showcases an effort made for developing virtual Hood slam test. The virtual model consists of BIW, hood, hinge joint, interface like CRFM and latch mechanism with spring preload. Analysis performed with LSDyna solver. An impact loading is applied by converting potential energy to kinetic energy, mimicking the hood dropping from a specified height on the hood latch.
2016-04-05
Technical Paper
2016-01-1549
Nicola Bartolini, Lorenzo Scappaticci, Francesco Castellani, Alberto Garinei
The knocking noise is a transient structural noise triggered by the shock absorber's piston rod vibrations that excites the vibration of chassis components. Piston rod vibrations can be caused by valves motion (opening and closing) and dry friction during stroke inversions. This study investigates the shock absorber knocking noise on a twintube gas-filled automotive shock absorber and the aim is to define an acceptance criterion (threshold level) for a sample check of the component. If infact the damper derives from a large mass production, may happen that small differences in the assembly might lead to different behaviours resulting in higher or lower levels of knocking noise. To achieve the goal, experimental tests were carried out at various excitation frequencies and amplitudes. Test were performed using a oleodynamic test bench monitoring displacement and force; accelerometers were placed in proximity of the rebound valve, on the body of the damper and on the piston rod.
2016-04-05
Technical Paper
2016-01-0499
Xu Zhang, Jennifer Johrendt
Successful manufacture of Carbon Fibre Reinforced Polymers (CFRP) by Long-Fibre Reinforced Thermoplastic (LFT) processes requires knowledge of the effect of numerous processing parameters such as temperature set-points, rotational machinery speeds, and matrix melt flow rates on the resulting material properties after the final compression moulding of the charge is complete. The degree to which the mechanical properties of the resulting material depend on these processing parameters is integral to the design of materials by any process, but the case study presented here highlights the manufacture of CFRP by LFT as a specific example. The material processing trials are part of the research performed by the International Composites Research Centre (ICRC) at the Fraunhofer Project Centre (FPC) located at the University of Western Ontario in London, Ontario, Canada.
2016-04-05
Technical Paper
2016-01-0479
Kuniaki Goto, Takashi kondo, Masakiyo Takahira, Eiji Umemura, Masashi Komada, Yasuhiko Nishimura
Generally, the field pass-by noise level measurement is not stable under the influence of weather conditions , background noise and driver’s skill.So, automobile manufactures try to reproduce proving ground driving on chassis dynamometer measurement.But, the tire noise on actual road surface is difficult to replace on indoor test. In 2016,new pass-by noise regulation (UN R51-03)will take effect in Europe and Japan etc. Furthermore , 2dB stricter regulation will take effect in 2020. In addition to the acceleration run of the current regulation , UN R51-03 requests constant speed run . Therefore, the efficient measurement is necessary for vehicle development. To solve the above mentioned issues , we have developed an indoor evaluation system capable of reproducing the tire noise on road surface.
2016-04-05
Technical Paper
2016-01-0274
Sharon L. Honecker, David J. Groebel, Adamantios Mettas
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 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
2016-01-0484
Chad W. Chichester
Silicone fluids are known to have high Viscosity Indices (VI), and high Oxidation Onset Temperatures (OOT). Silicone VI and OOT characteristics make those fluids appealing for use as lubricants in high temperature applications, and where lubricant longevity is desired. Despite thermal and oxidative benefits, silicones lubricants have a reputation as being poor lubricants in metal-to-metal applications, and are typically only selected for use in plastic applications. Most industrial knowledge about silicone lubricants is based on characteristics of PolyDiMethyl Siloxanes (PDMS), in which case, lubricity limitations do exists. However, there are other silicone based lubricating fluid technologies, that have been commercially available for decades, that far exceed known lubricity performance of PDMS, and in some ways can rival traditional synthetic hydrocarbon.
2016-04-05
Technical Paper
2016-01-0905
Robert J. Middleton, Omnaath Guptha Harihara Gupta, Han-Yuan Chang, George Lavoie, Jason Martz
This study evaluates 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 a 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 over the EPA’s FTP and HWY test schedules. The model test vehicle is a midsized sedan based on the MY2012 Ford Fusion with constant test weight of 3625 lbs, with constant drag and rolling resistance characteristics.
2016-04-05
Technical Paper
2016-01-0414
Nehal Sardar Rahim
"The Aisin A465 6-Speed Diesel Hybrid powertrain started production in early 2012 and is available in the North American market in the Hino 195 COE truck.  The suitability, and added fuel efficiency, of a Hybrid powertrain for Class 5 Box truck is very dependent on fleet usage conditions and duty cycle.  Aisin has undertaken real-world, extended mileage, durability testing on public roads to determine the operational modes for which such a powertrain is most suitable, and for which a fleet owner can expect significant fuel savings that will result in a payback period that justifies the higher initial cost of a hybrid system equipped commercial truck.  Data collected on the same Aisin proprietary durability test routes with a conventional Class 3-5 Cab Chassis truck provides insights into truck usage parameters that differ between Hybrid and conventional Class 3-5 commercial trucks.
2016-04-05
Technical Paper
2016-01-0463
Juan Sierra, Camilo Cruz, Luis Munoz, Santiago Avila, Elkin Espitia, Jaime Rodriguez
Brake systems are strongly related with safety of vehicles. Therefore a reliable design of the brake system is critical as vehicles operate in a wide range of environmental conditions, fulfilling different security requirements. Particularly, countries with mountainous geography expose vehicles to aggressive variations in altitude and road grade. These variations affect the performance of the brake system. In order to study how these changes affect the brake system, two approaches were considered. The first approach was centered on the development of an analytical model for the longitudinal dynamics of the vehicle during braking maneuvers. This model was developed at system-level, considering the whole vehicle. This allowed the understanding of the relation between the braking force and the altitude and road grade, for different fixed deceleration requirement scenarios. The second approach was focused on the characterization of the vacuum servo operation.
2016-04-05
Technical Paper
2016-01-0429
Paul Augustine, Timothy Hunter, Nathan Sievers, Xiaoru Guo
The performance of a structural design depends upon the assumptions made on input load. In order to estimate the input load, during the design stage of the suspension assembly of a BAJA car, designers invest immense amount of time and effort to formulate the mathematical model of the design. The theoretical formulations may include idealization errors which can affect the performance of the car as a final product. These errors in estimating design load will lead to more weight or less strength than needed. This discrepancy between the assumed input load 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 understand the real world loading of structures. A limitation of load cells is that the structure needs to be modified to accept the load cell and not all desired loading can be measured.
2016-04-05
Technical Paper
2016-01-1534
Rudolf Reichert, Pradeep Mohan, Dhafer Marzougui, Cing-Dao Kan, Daniel Brown
A detailed finite element model of a 2012 Toyota Camry was developed by reverse engineering. The model consists of 2.3M elements representing the geometry, thicknesses, material characteristics, and connections of relevant structural, suspension, and interior components of the mid-size sedan. This paper describes the level of detail of the simulation model, the validation process, and how it performs in various crash configurations, when compared to full scale test results. Under contract with the National Highway Safety Administration and the Federal Highway Administration, the Center for Collision Safety at the George Mason University has developed a fleet of vehicle models which have been made publicly available. The updated model presented in this paper is the latest finite element vehicle model with a high level of detail using state of the art modeling techniques.
2016-04-05
Technical Paper
2016-01-1594
Petter Ekman, Roland Gardhagen, Torbjorn Virdung PhD, Matts Karlsson
Considerable amounts of the everyday goods transport in Sweden is done with light trucks. In the last ten years (2005-2015) the number of light trucks has increased by 33% in Sweden. The majority of these light trucks are fitted with a swapbody, and encounter the same problem as many other truck configurations, namely that several different manufacturers contribute to the final shape of the vehicle. Due to this, the aerodynamics of the final vehicle is often not fully considered, hence there appear to be room for improving the aerodynamic performance. The flow around a light truck fitted with a swapbody has been investigated with use of Computational Fluid Dynamics (CFD). Focus has been on improving the swapbody shape in order to reduce the aerodynamic drag and the fuel consumption, but still keeping it usable for daily operations.
2016-04-05
Technical Paper
2016-01-0273
Richard DeJong, Se Ge Jung, John Van Baren
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
2016-01-0440
Li Jie, Wang Wenzhu, Gao Xiong, Zhang Zhenwei
The heavy truck often moves in a poor, long-distance and high-speed freight state environment, so drivers are easy to fatigue and goods are easily damaged. At the same time, compared to the passenger car, the ride comfort of heavy trucks has a lot of room for improvement. Therefore, the research on the ride comfort of heavy trucks becomes crucial.Based the elastic theory of Euler-Bernoulli beam with both free ends, a 6 DOF half rigid-elastic vibration model of the vertical dynamic response is developed, which is more suitable to the actual movement of heavy trucks. The DOFs include: vertical displacements of the body and each of two axles; the pitch displacement of the body; the first and second order bending displacements of the body. The root mean square values of body acceleration, dynamic deflections and relative dynamic loads act as evaluation index.
2016-04-05
Technical Paper
2016-01-0128
Philip Koopman, Michael Wagner
Software testing is too often simply a hunt for bugs, rather than a well considered exercise in ensuring quality. A more methodical approach than simply drive-patch-drive-patch will be required to deploy safe autonomous vehicles at scale. The development V process sets up a framework that ties each type of testing to a corresponding design or requirement document, but is insufficient to deal with the sorts of novel testing problems that face autonomous vehicles. Based on our experience with several years of stress-testing autonomous vehicles, we propose an autonomous vehicle testing approach that can be thought of as an extension to ISO 26262 practices and the traditional V processes. Our testing strategy matches well defined design, requirement, and environmental fault models with matching layers of phased testing and deployment. A multi-layered testing plan can manage exposure to help boot-strap fleet deployment in a methodical way.
2016-04-05
Technical Paper
2016-01-0139
Andreas Himmler, Klaus Lamberg, Tino Schulze, Jann-Eve Stavesand
Developers of safety-critical systems need to verify the output of software tools in order to ensure their suitability for safety-relevant applications. The importance of verification holds specifically for test automation tools that are used to run hardware-in-the-loop (HIL) tests of safety-related software automatically 24/7. This paper will focus on two aspects that maximize the productivity of a COTS test automation tool: (a) Minimize the efforts for tool users for tool certification and (b) maximize the productivity for tool application. The latter refers to a new concept of signal-based test description. It is common sense that a test automation tool that automatically performs tests 24/7 has a tool confidence level of TCL 3. This causes a major initial hurdle for tool users, since the resulting required tool qualification is time-consuming and requires advanced knowledge.
2016-04-05
Technical Paper
2016-01-0833
Lei Meng, Yuqiang Li, Karthik Nithyanandan, Timothy Lee, Chunnian Zeng, Chia-Fon Lee
To face the challenges of fossil fuel shortage and air pollution problems, there is growing interest in the potential usage of alternative fuels such as bio-ethanol and bio-butanol in internal combustion engines. The literature shows that the acetone in the Acetone-Butanol-Ethanol (ABE) blends plays an important part in improving the combustion performance and emissions, owing to its higher volatility. In order to study the effects of acetone addition into commercial gasoline, this study focuses on the differences in combustion, performance and emission characteristics of a port-injection spark-ignition engine fueled with pure gasoline (G100), ethanol-containing gasoline (E30) and acetone-ethanol-gasoline blends (AE30 at A:E volumetric ratio of 3:1). The tests were conducted at 1200RPM with the default calibration (for gasoline), at 3 bar and 5 bar BMEP under various equivalence ratios.
2016-04-05
Technical Paper
2016-01-1545
Huan Liu, Guoying Chen, Changfu Zong
Comparing with traditional steering system, motor and reducing mechanism are added to Electric Power Steering System(EPS), this part of the existence of additional hardware increase the friction torque of steering system, which affect vehicle’s steering portability, return-to-center performance and central road feel at low speed and high-speed. To overcome the friction resistance moment, and formulate the corresponding control strategy to exert friction compensation control system, appropriate friction model must be selected to describe the friction properties of EPS system. The current EPS friction model can’t describe the friction torque’s smoothness and hysteresis characteristics, so a new electric power steering system dynamic friction model based on normalized Bouc-Wen model is given, as well as its structure form and model features. In addition, experimental method has been used to identify corresponding parameters.
2016-04-05
Technical Paper
2016-01-0049
Jinwei Zhou, Roman Schmied, Alexander Sandalek, Helmut Kokal, Luigi del Re
The implementation of Advanced Driver Assistant Systems (ADAS) in production standard vehicles requires extensive test bench and field testing as the manufacturer has to guarantee for functionality and safety in all possible traffic environment situations. Especially field tests consume a lot of time and money which is the reason why methods that allow a reduction of field test hours obtain high attention. Virtual ADAS testing 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 drives. The idea is to reproduce environmental conditions obtained on a test drive within a simulation environment.
2016-04-05
Technical Paper
2016-01-0051
Hongyu Zheng, Mingxin Zhao
Electric power steering, active front wheel steering and steer by wire systems can improve the steering portability at low speed and ameliorate the steering feeling at high speed, so as to enhance the handling stability of the vehicle. It can even perform an active steering intervention in dangerous working conditions to increase the active safety of automobile. However, the development of the electric steering system , which needs to test and modify repeatedly, involves the machinery, the controller hardware , control algorithm and many other aspects of designs. Now the development of the electric steering system is mainly based on the way that combines the test of the electric steering hardware-in-loop(HIL) test bench with real vehicle road test. But the real vehicle test with higher cost, long cycle and vulnerable to space weather have the potential safety problems at the beginning of the system development.
2016-04-05
Technical Paper
2016-01-0052
Jihas Khan
HILS is a proven and essential part of embedded product development life cycle which strives to reduce effort, time and cost spent on automotive validation activities. An efficient HILS system allows to create a precise simulation environment for the ECU which believes that it is sitting inside the real vehicle and there by intended functionalities implemented in the same can be tested even before the vehicle prototypes or other ECUs or sensors and actuators are available. Inefficient and faulty HILS system provides erroneous test results which leads to wrong inferences. This paper is proposing a standardized process flow aided by specific documentation and design concepts which makes sure that the test system designed is robust and catering to the actual requirement. Main agenda of the paper is to design a test system which itself is more robust than the expected device under test.
2016-04-05
Technical Paper
2016-01-0055
Mark Steffka, Cyrous Rostamzadeh
Automotive systems can generate un-intentional radio frequency energy. The levels of these emissions must be below maximum values set by the Original Equipment Manufacturer (OEM) for customer satisfaction and/or in order to meet governmental requirements. Due to the complexity of electromagnetic coupling mechanisms that can occur on a vehicle, many times it is difficult to measure and identify the noise source(s) without the use of an electromagnetic interference (EMI) receiver or spectrum analyzer (SA). An efficient and effective diagnostic solution can be to use a low-cost portable, battery powered RF detector with wide dynamic range as an alternative for automotive electromagnetic compatibility (EMC) and design engineers to identify, locate, and resolve radio frequency (RF) noise problems. A practical circuit described here can be implemented easily with little RF design knowledge, or experience.
2016-04-05
Technical Paper
2016-01-1550
Ming Peng, Xuexun Guo, Junyi Zou, Chengcai Zhang
This paper presents a novel concept of the application of the hydraulic electromagnetic energy-regenerative shock absorber (HESA) into the commercial vehicle suspension system and the vehicle road performances are simulated by the evaluating indexes (e.g. the root-mean-square values of vertical acceleration of sprung mass, dynamic tire-ground contact force, suspension deflection and harvested power). Firstly, the configuration and working principle of the HESA are introduced. Then, the damping characteristics of the HESA and the seven-degrees-of-freedom vehicle dynamics were modeled respectively before derive the dynamic characteristics of a vehicle equipped with the HESA. The control current is fixed at 7A to match the similar damping effect of traditional linear damper on the basis of the energy conversion method of nonlinear shock absorber.
2016-04-05
Technical Paper
2016-01-0796
Ashish Shah, Per Tunestal, Bengt Johansson
This article presents a study related to application of pre-chamber ignition system in heavy duty natural gas engine which, as previously shown by the authors, can extend the limit of fuel-lean combustion and hence improve fuel efficiency and reduce emissions. A previous study about the effect of pre-chamber volume and nozzle diameter on a single cylinder 2 liter truck-size engine resulted in recommendations for optimal pre-chamber geometry settings. The current study is to determine the dependency of those settings on the engine size. For this study, experiments are performed on a single cylinder 9 liter large bore marine engine with similar pre-chamber geometry and a test matrix of similar and scaled pre-chamber volume and nozzle diameter settings. The effect of these variations on main chamber ignition and the following combustion is studied to understand the scalability aspects of pre-chamber ignition. Indicated efficiency and engine-out emission data is also presented.
2016-04-05
Technical Paper
2016-01-0050
Huafeng Yu, Chung-Wei Lin, BaekGyu Kim
Modern vehicles can have millions of lines of software, for vehicle control, infotainment, etc. The quality and correctness of the software play a key role in the safety of whole vehicle. 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 medical devices and avionics. At the same time, safety-relevant standards and techniques, including ISO 26262 and assurance case, have been well adopted.
2016-04-05
Technical Paper
2016-01-0105
Yogesh Chandra Sharma
In this technical paper, a conceptual framework for collective thermal behavior of multiple terminals in an electrical connector has been discussed. A terminal in the connector affects ambient temperature of the surrounding cavities due to resistive heat loss of current passing through that terminal by conduction and convection (heat flow mechanisms). Multiple parameters (size, geometry, material, plating etc…) decide thermal property of a terminal. Hence, it is complex to identify the method for each terminal series, which will exhibit the same properties as defined by the manufacturer. To simplify the understanding of this interaction, an alternative method is identified. This method utilizes the manufacturing curves provided by the manufacturer, which include the effects of all the design parameters of terminals. In this method, the important step is to characterize the terminal manufacturing curves.
2016-04-05
Technical Paper
2016-01-0936
Anoop Reghunathan Nair, Brett Schubring, Kiran Premchand, Andrew Brocker, Peter Croswell, Craig DiMaggio, Homayoun Ahari, Jeffrey Wuttke, Michael Zammit, Michael Andrew Smith
New Particulate Matter (PM) and/or Particulate Number (PN) regulations throughout the world have created an interest in aftertreatment solutions as an option to comply with the legislation. Limitations in other criteria emissions cannot be sacrificed to accomplish the reduction of PM/PN. Catalytic functions and volume requirement for consistent catalytic performance was determined through NOX , CO and HC conversion over U.S. Federal Test Procedure 75 (FTP-75) and US06 Supplemental Federal Test Procedure (US06) on a catalytic wall flow GPF (4WC) and flow through TWC catalyst. Four flow-through TWC and four wall-flow GPF catalysts were used for the study. All the exhaust systems had the same PGM loading and different cell structures. It was observed that replacing the flow through catalyst with a GPF will reduce the effective volume, which results in a more compact architecture.
2016-04-05
Technical Paper
2016-01-1062
Ramachandran Ragupathy, Pothiraj K, C Chendil, T Kumar Prasad, Prasanna vasudevan
In today's world where fuel efficiency and reduced emissions are fast becoming the order of the day, hybrid powertrains are a feasible intermediate step to clean transportation. Hybrid powertrains generally add an electric propulsion system in addition to propulsion power from conventional internal combustion engines. As such, the powertrain complexity increases both due to the number of interplaying systems and due to the advanced systems used to control system performance in an optimum manner. This paper shall describe, in detail and in particular, the effects of torsional impact loads in a mild hybrid electric powertrain and the mitigation measures adopted to resolve them. The powertrain configuration consists of a diesel engine with a crankshaft mounted electric machine. The torque from the engine/electric machine combination passes through a dry clutch to a manual transaxle.
Viewing 61 to 90 of 23980

Filter