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Viewing 121 to 150 of 15362
2017-03-28
Technical Paper
2017-01-1147
Hyunjun Kim, Jingeon Kang, Dongsuk Kum
Abstract Input- and output-split hybrids using a single planetary gear (PG) can provide high fuel economy, but they tend to suffer from low acceleration performance. In order to improve their acceleration performance, speed reduction (multiplication) gears (SRG/SMG) have often been employed in various mass-produced split hybrids. In fact, adding one SRG (SMG) to input- or output-split hybrids can improve not only the acceleration performance, but also the fuel economy. Nevertheless, the full potentials of using SRGs (SMGs) have not yet been thoroughly investigated because the design space of input- and output-split configurations using one SRG (SMG) is huge; 432 configurations can be generated using two PGs where one PG is used as an SRG/SMG. Thus, in order to investigate the impacts of SRG (SMG) within a reasonable time, an efficient analysis procedure is required.
2017-03-28
Technical Paper
2017-01-1237
Ahmad Arshan Khan, Michael J. Kress
Abstract For high performance motor controls applications such as electric vehicles, accurate motor parameter knowledge is required. Motor parameters like d-axis inductance, q-axis inductance, resistance and permanent magnet flux linkage are difficult to obtain and measure directly. These four parameters can be reduced to three parameters resistance, d-axis and q axis flux linkage. In this paper, a new scheme is proposed to approximate d-axis and q-axis flux linkage using measured torque, dq-axis measured current, and dq-axis voltage commands to the inverter. d-axis and q-axis flux linkages are estimated over a range of d-axis and q-axis currents that fully map the desired motor operation region.
2017-03-28
Technical Paper
2017-01-1239
Naoya Take, Takuya Kadoguchi, Masao Noguchi, Kimihiro Yamanaka
Abstract Power modules are used to operate three-phase alternating current motors in hybrid vehicles and electric vehicles. Good fuel efficiency and high power density are required in the field of hybrid vehicles. To achieve this goal, the miniaturization of the power module will be necessary. This trend may make a current density, which is created by insulated gate bipolar transistors (IGBTs) and free wheel diodes (FWDs), higher in power modules. Solder is often used as the joint material of power modules. It is known that a current density larger than 10 kA/cm2 causes solder electromigration. This phenomenon may cause delamination of the joint area. In addition, the ambient temperature has an influence on electromigration. The temperature of an engine compartment is high, so it is likely to cause electromigration. However, the current density of the double-sided cooling power modules in 2007 with solder joint is lower than 0.4 kA/cm2, and this value is lower than 10 kA/cm2.
2017-03-28
Technical Paper
2017-01-1245
Takamitsu Tajima, Hideki Tanaka, Takeo Fukuda, Yoshimi Nakasato, Wataru Noguchi, Yoshikazu Katsumasa, Tomohisa Aruga
Abstract The use of electric vehicles (EV) is becoming more widespread as a response to global warming. The major issues associated with EV are the annoyance represented by charging the vehicles and their limited cruising range. In an attempt to remove the restrictions on the cruising range of EV, the research discussed in this paper developed a dynamic charging EV and low-cost infrastructure that would make it possible for the vehicles to charge by receiving power directly from infrastructure while in motion. Based on considerations of the effect of electromagnetic waves, charging power, and the amount of power able to be supplied by the system, this development focused on a contact-type charging system. The use of a wireless charging system would produce concerns over danger due to the infiltration of foreign matter into the primary and secondary coils and the health effects of leakage flux.
2017-03-28
Technical Paper
2017-01-1220
Ahmad Arshan Khan
Abstract In an interior permanent magnet machine, magnet temperature plays a critical role in determining optimal current control trajectory. Monitoring magnet temperature is a challenging task. In lab and various specialized applications, infrared sensors or thermocouples are used to measure the temperature. But it adds cost, maintenance issues and their integration to electric machine drives could be complicated. To tackle issues due to sensor based methods, various sensorless model based approaches are proposed in the literature recently such as flux observer, high-frequency signal injection, and thermal models, etc. Although magnet temperature monitoring received a lot of attention of researchers, very few papers give a detailed overview of the effects of magnet temperature on motor control from a controls perspective. This paper discusses the impact of magnet temperature variation on Maximum Torque per Ampere control and Flux Weakening Control trajectory.
2017-03-28
Technical Paper
2017-01-1555
Mirosław Jan Gidlewski, Krystof JANKOWSKI, Andrzej MUSZYŃSKI, Dariusz ŻARDECKI
Abstract Lane change automation appears to be a fundamental problem of vehicle automated control, especially when the vehicle is driven at high speed. Selected relevant parts of the recent research project are reported in this paper, including literature review, the developed models and control systems, as well as crucial simulation results. In the project, two original models describing the dynamics of the controlled motion of the vehicle were used, verified during the road tests and in the laboratory environment. The first model - fully developed (multi-body, 3D, nonlinear) - was used in simulations as a virtual plant to be controlled. The second model - a simplified reference model of the lateral dynamics of the vehicle (single-body, 2D, linearized) - formed the basis for theoretical analysis, including the synthesis of the algorithm for automatic control. That algorithm was based on the optimal control theory.
2017-03-28
Technical Paper
2017-01-0160
Longjie Xiao, Tianming He, Gangfeng Tan, Bo Huang, Xianyao Ping
Abstract While the car ownership increasing all over the world, the unutilized thermal energy in automobile exhaust system is gradually being realized and valued by researchers around the world for better driving energy efficiency. For the unexpected urban traffic, the frequent start and stop processes as well as the acceleration and deceleration lead to the temperature fluctuation of the exhaust gas, which means the unstable hot-end temperature of the thermoelectric module generator (TEG). By arranging the heat conduction oil circulation at the hot end, the hot-end temperature’s fluctuation of the TEG can be effectively reduced, at the expense of larger system size and additional energy supply for the circulation. This research improves the TEG hot-end temperature stability by installing solid heat capacity material(SHCM) to the area between the outer wall of the exhaust pipe and the TEG, which has the merits of simple structure, none energy consumption and light weight.
2017-03-28
Technical Paper
2017-01-0371
Raju Gandikota, Amit Nair, Kurt Miller
Abstract Testing elastomeric materials that undergo large strains pose challenges especially when establishing failure criteria. The failure criterion for composites and polymers based on finite elasticity published by Feng (1) requires testing under uniaxial and biaxial stretching modes. The classic inflation of a circular disk for biaxial stretch mode poses stability and safety challenges. The test can also be sensitive to end constraints resulting in failure of materials at the constraints. Biaxial stretching with a hemispherical punch is explored in this work. The biaxial stretching allows controlled and repeatable testing. It establishes a clear and reliable failure mechanism of the material at the poles. Through a combination of testing and numerical methods, the stretch ratios and its relation to failure have been established. The method greatly simplifies testing and provides reliable data for a failure criterion for elastomers in numerical modeling.
2017-03-28
Technical Paper
2017-01-0341
Seyyedvahid Mortazavian, Javid Moraveji, Reda Adimi, Xingfu Chen
Abstract In this study, a finite element analysis method is developed for simulating a camshaft cap punching bench test. Stiffness results of simulated camshaft cap component are correlated with test data and used to validate the model accuracy in terms of material and boundary conditions. Next, the method is used for verification of cap design and durability performance improvement. In order to improve the computational efficiency of the finite element analysis, the punch is replaced by equivalent trigonometric distributed loads. The sensitivity of the finite element predicted strains for different trigonometric pressure distribution functions is also investigated and compared to strain gage measured values. A number of equivalent stress criteria are also used for fatigue safety factor calculations.
2017-03-28
Technical Paper
2017-01-0626
LeeAnn Wang, George Garfinkel, Ahteram Khan, Mayur Harsha, Prashanth Rao
Abstract When a driver completes an aggressive drive cycle on a hybrid vehicle, the High Voltage (HV) battery system may be at risk of exceeding the power limit temperature, due to continuous absorption of radiative and convective heat from the environment, such as from exhaust and pavement, even after key-off. In such a case, in the absence of active cooling, the vehicle may not be keyed-on until battery temperatures are reduced below critical values. A transient thermal analysis is conducted on a HV battery system to simulate the key-off operation using an effective Computational Fluid Dynamics (CFD) methodology. Two stages are considered in this methodology to capture the complexity of the geometry and the multiple phenomena that need to be simulated in the model. The introduced modeling technique can be used for Full Hybrid Electric Vehicle (FHEV) and Plug-in Hybrid Electric Vehicle (PHEV) transient key-off situations.
2017-03-28
Technical Paper
2017-01-0182
Gautam Peri, Saravanan Sambandan, S. Sathish Kumar
Abstract Cool down of a passenger vehicle cabin is a preferred method to test the efficiency of the vehicle HVAC (Heating, Ventilation and Air Conditioning) system. The intended primary objective of a passenger vehicle air conditioning system is to ensure thermal comfort to the passengers seated inside at all prevailing conditions. Presently 1-D analysis plays a major role in determining the conformation of the selected system to achieve the desired results. Virtual analysis thus saves a lot of time and effort in predicting the system performance in the initial development phase of the vehicle HVAC systems. A variety of parameters play an important role in achieving the above thermal comfort. Thermal comfort is measured using the Human comfort sensor for all the passengers seated inside.
2017-03-28
Technical Paper
2017-01-0164
Venkatesan Muthusamy, S. Sathish Kumar, Saravanan Sambandan
Abstract In an automotive air-conditioning (AC) system, upfront prediction of the cabin cool down rate in the initial design stage will help in reducing the overall product development (PD) time. Vehicle having higher seating capacity will have higher thermal load and providing thermal comfort to all passengers uniformly is a challenging task for the automotive HVAC (Heating Ventilation and Air conditioning) industry. Dual HVAC unit is generally used to provide uniform cooling to a large cabin volume. One dimensional (1D) simulation is being extensively used to predict the HVAC performance during the initial stage of PD. The refrigerant loop with components such as compressor, condenser, TXV and evaporator was modeled. The complicated vehicle cabin including the glazing surfaces and enclosures were modeled as a three row duct system using 1D tool AMESim®. The material type, density, specific heat capacity and thermal conductivity of the material were specified.
2017-03-28
Technical Paper
2017-01-0166
Noori Pandit
Abstract The effects of substituting a 12 mm thick subcool on top condenser in place of a 16 mm subcool on bottom condenser are evaluated in a vehicle level AC pull down test. The A to B testing shows that a thinner condenser with subcool on top exhibits no degradation in AC performance while resulting in a lower total system refrigerant charge. The results are from vehicle level tests run in a climatically controlled vehicle level wind tunnel to simulate an AC pull down at 43°C ambient. In addition to cabin temperature and AC vent temperatures, comparison of compressor head pressures was also done. The conclusion of the study was that a standard 16 mm thick subcool on bottom IRD condenser can be replaced by a 12 mm thick subcool on top IRD condenser with no negative effects on performance.
2017-03-28
Technical Paper
2017-01-1410
Richard F Lambourn, James Manning
Abstract It can happen, following a collision between a car and a pedestrian or in a deliberate assault with a motor vehicle, that the pedestrian comes to be caught or wedged beneath the car, and that the driver then travels on for a considerable distance, afterwards claiming to have been unaware of the presence of the person. However, police, lawyers and jurors are often incredulous that the driver should not have been able to “feel” that there was something underneath his car. The authors have investigated the matter by carrying out practical tests with suitable cars and dummies. This paper describes instrumented tests performed by the authors following one such incident, and gives accounts of two previous incidents investigated in a more subjective fashion. The general conclusion is that the effect on the behavior of the car is very small and that a driver might indeed be unaware that there was a person trapped beneath them.
2017-03-28
Technical Paper
2017-01-1240
Koki Matsushita
Abstract For the purpose of improving vehicle fuel efficiency, it is necessary to reduce energy loss in the alternator. We have lowered the resistance of the rectifying device and connecting components, and control the rectifying device with an IC to reduce rectification loss. For the package design, we have changed the structure of the part on which the rectifying device is mounted into a high heat dissipation type. The new structure has enabled optimizing the size of the rectifying device, resulting in the reduction of size of the package. In addition, the rectifying device is mounted using a new soldering material and a new process, which has improved the reliability of the connection. Moreover, since the alternator has introduced a new system, the controller IC has a function for preventing malfunction of the rectifying device and a function for detecting abnormalities, in order to ensure safety.
2017-03-28
Technical Paper
2017-01-1231
Chun Tang, Natee Limsuwan, Nurani Chandrasekhar, Zhichun Ma, Jacob Krizan, Joel Hetrick, Wei Wu
Abstract The current of an electric machine driven by PWM switching inverter is not ideal sinusoidal, containing different levels of harmonics. The current harmonics have important impact on the electrical machine torque ripple which could translate into transmission and vehicle level Noise Vibration and Harshness (NVH). In this work, the current waveforms were measured from dyno test at prescribed torque and speed levels, and the electric machine torque ripple was computed with the measured current. This paper will focus on the investigation of the current harmonics behaviors and features at various torque and speed conditions, the impact on torque ripple, and the possible mitigation method to reduce torque ripple.
2017-03-28
Technical Paper
2017-01-1427
Daniel Koch, Gray Beauchamp, David Pentecost
Abstract Tire disablement events can cause a drag force that slows a vehicle. In this study, the magnitude of the deceleration was measured for different phases of 29 high speed tire tread separation and air loss tests. These deceleration rates can assist in reconstructing the speed of a vehicle involved in an accident following a tire disablement.
2017-03-28
Technical Paper
2017-01-0331
Qiuren Chen, Haiding Guo, Katherine Avery, Xuming Su, HongTae Kang
Abstract Fatigue crack growth tests have been carried out to investigate the mixed mode fatigue crack propagation behavior of an automotive structural adhesive BM4601. The tests were conducted on a compound CMM (Compact Mixed Mode) specimen under load control with 0.1 R ratio and 3Hz frequency. A long distance moving microscope was employed during testing to monitor and record the real time length of the fatigue crack in the adhesive layer. The strain energy release rates of the crack under different loading angles, crack lengths and loads were calculated by using finite element method. The pure mode I and mode II tests show that an equal value of mode I strain energy release rate results in over ten times higher FCGR (Fatigue Crack Growth Rate) than the mode II stain energy release rate does. The mixed mode tests results show that under a certain loading angle, the mixed mode FCGR is changed by changing the load, which is contrary to the find in pure mode I and mode II tests.
2017-03-28
Technical Paper
2017-01-1226
Nurani Chandrasekhar, Chun Tang, Natee Limsuwan, Joel Hetrick, Jacob Krizan, Zhichun Ma, Wei Wu
Abstract Noise and Vibration (NVH) characteristic of an electric machine (e-Machine) is the outcome of complex interaction between source level disturbances and the surrounding structure to which the e-Machine is attached. Key e-Machine metrics that objectively quantify source level disturbance include torque ripple and radial electro-magnetic forces. These disturbances can radiate directly from the e-Machine housing (air-borne component) and also can be transmitted through the structural attachments like stator bolts, stator ring, powertrain mounts etc. (structure-borne component). In the e-machine driven by PWM switching inverter, current is not perfectly sinusoidal but contain different level of harmonics. Current harmonics impact Torque ripple, which in turn would translate into undesirable noise and vibration. There is very limited literature referencing the influence of current harmonics on torque ripple and e-machine NVH.
2017-03-28
Technical Paper
2017-01-0134
Jan Eller, Heinrich Reister, Thomas Binner, Nils Widdecke, Jochen Wiedemann
Abstract There is a growing need for life-cycle data – so-called collectives – when developing components like elastomer engine mounts. Current standardized extreme load cases are not sufficient for establishing such collectives. Supplementing the use of endurance testing data, a prediction methodology for component temperature collectives utilizing existing 3D CFD simulation models is presented. The method uses support points to approximate the full collective. Each support point is defined by a component temperature and a position on the time axis of the collective. Since it is the only currently available source for component temperature data, endurance testing data is used to develop the new method. The component temperature range in this data set is divided in temperature bands. Groups of driving states are determined which are each representative of an individual band. Each of the resulting four driving state spaces is condensed into a substitute load case.
2017-03-28
Technical Paper
2017-01-0260
Yuanying Wang, Heath Hofmann, Denise Rizzo, Scott Shurin
Abstract This paper presents a computationally-efficient model of heat convection due to air circulation produced by rotor motion in the air gap of an electric machine. The model calculates heat flux at the boundaries of the rotor and stator as a function of the rotor and stator temperatures and rotor speed. It is shown that, under certain assumptions, this mapping has the homogeneity property. This property, among others, is used to pose a structure for the proposed model. The coefficients of the model are then determined by fitting the model to the results of a commercial Computational Fluid Dynamics (CFD) simulation program. The accuracy of the new model is compared to the CFD results, shown an error of less than 0.3% over the studied operating range.
2017-03-28
Technical Paper
2017-01-0121
Zhijia Yang, Jesus PradoGonjal, Matthew Phillips, Song Lan, Anthony Powell, Paz Vaqueiro, Min Gao, Richard Stobart, Rui Chen
Abstract Thermoelectric generator (TEG) has received more and more attention in its application in the harvesting of waste thermal energy in automotive engines. Even though the commercial Bismuth Telluride thermoelectric material only have 5% efficiency and 250°C hot side temperature limit, it is possible to generate peak 1kW electrical energy from a heavy-duty engine. If being equipped with 500W TEG, a passenger car has potential to save more than 2% fuel consumption and hence CO2 emission reduction. TEG has advantages of compact and motionless parts over other thermal harvest technologies such as Organic Rankine Cycle (ORC) and Turbo-Compound (TC). Intense research works are being carried on improving the thermal efficiency of the thermoelectric materials and increasing the hot side temperature limit. Future thermoelectric modules are expected to have 10% to 20% efficiency and over 500°C hot side temperature limit.
2017-03-28
Technical Paper
2017-01-1042
Eric J. Passow, Paras Sethi, Max Maschewske, Jason Bieneman, Kimm Karrip, Paul Truckel
Abstract Current market demands in conjunction with increasingly stringent emission legislation have vehicle manufactures striving to improve fuel economy and reduce CO2 emissions. One way to meet these demands is through engine downsizing. Engine downsizing allows for reduced pumping and frictional losses. To maintain acceptable drivability and further increase efficiency, power density increase through the addition of boosting is employed. Furthermore, efficiencies have been realized through the use of high gear count transmissions, providing an opportunity for manufactures to effectively down speed the engine whilst still achieving the desired drivability characteristics. As a result of these efficiency improvements, gasoline turbo charged direct injected (GTDI) engines are developed for and tend to operate in low engine speed, high torque conditions .
2017-03-28
Technical Paper
2017-01-1065
Douglas R. Martin, Benjamin Rocci
Abstract Exhaust temperature models are widely used in the automotive industry to estimate catalyst and exhaust gas temperatures and to protect the catalyst and other vehicle hardware against over-temperature conditions. Modeled exhaust temperatures rely on air, fuel, and spark measurements to make their estimate. Errors in any of these measurements can have a large impact on the accuracy of the model. Furthermore, air-fuel imbalances, air leaks, engine coolant temperature (ECT) or air charge temperature (ACT) inaccuracies, or any unforeseen source of heat entering the exhaust may have a large impact on the accuracy of the modeled estimate. Modern universal exhaust gas oxygen (UEGO) sensors have heaters with controllers to precisely regulate the oxygen sensing element temperature. These controllers are duty cycle based and supply more or less current to the heating element depending on the temperature of the surrounding exhaust gas.
2017-03-28
Technical Paper
2017-01-1671
Johannes Bach, Marc Holzäpfel, Stefan Otten, Eric Sax
Abstract Enhanced technological capabilities render the application of various, increasingly complex, functional concepts for automated driving possible. In the process, the significance of automotive software for a satisfactory driving experience is growing. To benefit from these new opportunities, thorough assessment in early development stages is highly important. It enables manufacturers to focus resources on the most promising concepts. For early assessment, a common approach is to set up vehicles with additional prototyping hardware and perform real world testing. While this approach is essential to assess the look-and-feel of newly developed concepts, its drawbacks are reduced reproducibility and high expenses to achieve a sufficient and balanced sample. To overcome these drawbacks, new flexible, realistic and preferably automated virtual test methods to complement real world verification and validation are especially required during early development phases.
2017-03-28
Technical Paper
2017-01-0738
Akhilendra Pratap Singh, Avinash Kumar Agarwal
Abstract Premixed charge compression ignition (PCCI) combustion is an advanced combustion technique, which has the potential to be operated by alternative fuels such as alcohols. PCCI combustion emits lower oxides of nitrogen (NOx) and particulate matter (PM) and results thermal efficiency similar to conventional compression ignition (CI) engines. Due to extremely high heat release rate (HRR), PCCI combustion cannot be used at higher engine loads, which make it difficult to be employed in production grade engines. This study focused on development of an advanced combustion engine, which can operate in both combustion modes such as CI combustion as well as PCCI combustion mode. This Hybrid combustion system was controlled by an open engine control unit (ECU), which varied the fuel injection parameters for mode switching between CI and PCCI combustion modes.
2017-03-28
Technical Paper
2017-01-0324
Anbo Pan, Ashley Walsh, Mark Dearth, Xiao Qing Zhang
Abstract Ford China had carried out a research project to validate the target compounds that lead to Chinese customers’ complaint about interior cabin odor. The aim of the study was to understand the sensitivity of the customers, using experimental design and determine which substances that are key contributors to customer odor concerns. In this research, acetaldehyde, toluene, xylene, ethylbenzene, acetone and butyraldehyde are used to conduct odor re-manufacture study through reconstituting their concentration in vehicles, it is concluded that compound classes aromatics, aldehydes, and ketones have direct relationship to the odor concerns in China.
2017-03-28
Technical Paper
2017-01-1417
Enrique Bonugli, Richard Watson, Mark Freund, Jeffrey Wirth
Abstract This paper reports on seventy additional tests conducted using a mechanical device described by Bonugli et al. [4]. The method utilized quasi-static loading of bumper systems and other vehicle components to measure their force-deflection properties. Corridors on the force-deflection plots, for various vehicle combinations, were determined in order to define the system stiffness of the combined vehicle components. Loading path and peak force measurements can then be used to evaluate the impact severity for low speed collisions in terms of delta-v and acceleration. The additional tests refine the stiffness corridors, previously published, which cover a wide range of vehicle types and impact configurations. The compression phase of a low speed collision can be modeled as a spring that is defined by the force-deflection corridors. This is followed by a linear rebound phase based on published restitution values [1,5].
2017-03-28
Technical Paper
2017-01-1540
Yuri M. Lopes, Maxwell R. Taylor, Todd H. Lounsberry, Gregory J. Fadler
Abstract Typical production vehicle development includes road testing of a vehicle towing a trailer to evaluate powertrain thermal performance. In order to correlate tests with simulations, the aerodynamic effects of pulling a trailer behind a vehicle must be estimated. During real world operation a vehicle often encounters cross winds. Therefore, the effects of cross winds on the drag of a vehicle–trailer combination should be taken into account. Improving the accuracy of aerodynamic load prediction for a vehicle-trailer combination should in turn lead to improved simulations and better thermal performance. In order to best simulate conditions for real world trailer towing, a study was performed using reduced scale models of a Sport Utility Vehicle (SUV) and a Pickup Truck (PT) towing a medium size cargo trailer. The scale model vehicle and trailer combinations were tested in a full scale wind tunnel.
2017-03-28
Technical Paper
2017-01-0123
Saiful Bari
Abstract In general, diesel engines have an efficiency of about 35% and hence, a considerable amount of energy is expelled to the ambient air. In water-cooled engines, about 25%, 33% and 7% of the input energy are wasted in the coolant, exhaust gas, and friction, respectively. The heat from the exhaust gas of diesel engines can be an important heat source to provide additional power and improve overall engine efficiency. Studies related to the application of recoverable heat to produce additional power in medium capacity diesel engines (< 100 kW) using separate Rankine cycle are scarce. To recover heat from the exhaust of the engine, an efficient heat exchanger is necessary. For this type of application, the heat exchangers are needed to be designed in such a way that it can handle the heat load with reasonable size, weight and pressure drop. This paper describes the study of a diesel generator-set attached with an exhaust heat recovery system.
Viewing 121 to 150 of 15362