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Viewing 91 to 120 of 33097
2017-03-28
Technical Paper
2017-01-0962
Jian Gong, Di Wang, Avra Brahma, Junhui Li, Neal Currier, Aleksey Yezerets, Pingen Chen
Abstract Oxygen storage capacity (OSC) is one of the most critical characteristics of a three-way catalyst (TWC) and is closely related to the catalyst aging and performance. In this study, a dynamic OSC model involving two oxygen storage sites with distinct kinetics was developed. The dual-site OSC model was validated on a bench reactor and a natural gas engine. The model was capable of predicting temperature dependence on OSC with H2, CO and CH4 as reductants. Also, the effects of oxygen concentration and space velocity on the amount of OSC were captured by the model. The validated OSC model was applied to simulate lean breakthrough phenomena with varied space velocities and oxygen concentrations. It is found that OSC during lean breakthrough is not a constant for a particular TWC catalyst and is dependent on space velocity and oxygen concentration. Specifically, breakthrough time exhibits a non-linear, inverse correlation to oxygen flux.
2017-03-28
Technical Paper
2017-01-1064
Mustafa Yıldırım
Abstract Engine design is crucial in terms of NVH. It is the sources of vibration for a vehicle. Nowadays engine tends to being smaller and less stiff and more powerful according to predecessor. Small engines with high power is inherently generates extreme force and vibrations and accordingly generates more noise. Thus engine structure and also engine main components should be designed to prevent this vibration. There are two main sources: One of them is combustion and other is inertia loads. Due to this sources engine structure can cause severe vibration and accordingly this can cause noise via transmitting it into vehicle with both structure and airborne. This paper focused on to reduce engine vibration level with changing the combustion inputs such as cylinder pressure parameters and inertia parameters like piston mass, conrod length and balancing parameters. Design of experiment is used to obtain most robust case in terms of NVH.
2017-03-28
Technical Paper
2017-01-1148
Toumadher Barhoumi, Hyunjun Kim, Dongsuk Kum
Abstract Finding optimal split hybrid configurations through exhaustive search is almost intractable, mainly due to the huge design space, e.g. 252 compound split configurations using two planetary gear sets (PG). Thus, a systematic exhaustive design methodology is required to find optimal configurations. While most of the prior studies proposed methodologies that assess the performance within the physical design space, i.e. based on the powertrain configurations, this paper proposes a compound lever-based comprehensive design methodology. The (virtual) compound lever is an attractive design tool defined by two design variables, i.e. α and β, that omits the redundancy existing within the physical design space, thus, reduces the computational load. The proposed method explores the entire (virtual) compound lever design space to find optimal compound split configurations with outstanding fuel economy and acceleration performance.
2017-03-28
Technical Paper
2017-01-1057
Paul Zeng, Debabrata Paul, Vincent Solferino, Mark Stickler
1. Abstract Valvetrain ticking noise is one of the key failure modes in noise vibration harshness (NVH) evaluation at idle. It affects customer satisfaction inversely. In this paper, the root cause of the valvetrain ticking noise and key parameters that impact ticking noise will be presented. A physics based math model has been developed and integrated into a parameterized multi-body dynamic model. The analytical prediction has been correlated with testing data. Valvetrain ticking noise control is discussed.
2017-03-28
Technical Paper
2017-01-1062
Abdelkrim Zouani, Gabriela Dziubinschi, Vidya Marri, Simon Antonov
Abstract In modern automotive engines, Variable Displacement Oil Pump (VDOP) is becoming the pump of choice to enable reduction in friction and delivery of stringent fuel economy. However, this pump creates pressure ripples, at the outlet port during oil pump shaft rotation, causing oscillating forces within the system and leading to the generation of tonal noises and vibrations. In order to minimize the level of noise, different porting geometries and vane spacing are used. This paper describes an optimization method intended to identify the best possible spacing of the vanes in the conventional 7-vanes, 9-vanes and 11-vanes oil pumps. The method integrates a Matlab routine with the modeFRONTIER software to create the required design space in order to perform a multi-objective optimization using a genetic algorithm. Results of this optimization method are discussed and a design guideline for the VDOP vane spacing is disclosed.
2017-03-28
Technical Paper
2017-01-1192
Amardeep Sidhu, Afshin Izadian, Sohel Anwar
In this paper, multiple-model adaptive estimation techniques have been successfully applied to fault detection and identification in lithium-ion batteries. The diagnostic performance of a battery depends greatly on the modeling technique used in representing the system and the associated faults under investigation. Here, both linear and non-linear battery modeling techniques are evaluated and the effects of battery model and noise estimation on the over-charge and over-discharge fault diagnosis performance are studied. Based on the experimental data obtained under the same fault scenarios for a single cell, the non-linear model based detection method is found to perform much better in accurately detecting the faults in real time when compared to those using linear model based method.
2017-03-28
Technical Paper
2017-01-1178
Ken Laberteaux, Karim Hamza
Abstract This work presents a simulation-based modeling of the equivalent greenhouse gas (GHG) of plugin hybrid electric vehicles (PHEVs) for real driving patterns obtained from monitoring of real vehicles in public survey data sets such as the California Household Travel Survey (CHTS). Aim of the work is to highlight differences in attainable GHG reduction by adopting a PHEV instead of a conventional vehicle (CV) for different driving patterns obtained from real-world sub-populations of vehicles. Modeling of the equivalent GHG for a trip made by a PHEV can be challenging since it not only depends on the vehicle design and driving pattern of the trip in question, but also on: i) all electric range (AER) of the PHEV, ii) “well to tank” (W2T) equivalent GHG of the electricity used to charge the battery, as well as, iii) battery depletion in previous trips since the last charging event.
2017-03-28
Technical Paper
2017-01-1205
Letao Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai
Abstract To monitor and guarantee batteries of electric vehicles in normal operation, battery models should be established primarily for the further application in battery management system such as parameter identification and state estimation including state of charge (SOC), state of health (SOH) and so on. In this paper, an improved battery modeling method is proposed which is based on the recursive least square (RLS) algorithm employing an optimized objective function. The proposed modified objective function not only includes the normal sum of voltage error squares between measured voltage and model output voltage but also introduces a new variable representing the sum of first order difference error squares for both kinds of voltages. This specialty can undoubtedly guarantee better agreement for the measured output and the model output. The battery model used in this paper is selected to be the conventional second order equivalent circuit model.
2017-03-28
Technical Paper
2017-01-1169
Ahmed M. Ali, Alhossein Mostafa Sharaf, Hesham Kamel, Shawky Hegazy
Abstract This paper presents an integrated experimental and simulation investigation which is conducted on a series hybrid electric vehicle. The mathematical model is simulated in two distinct environments; MATLAB/Simulink and GT-Suite. An experimental test rig is devised in order to measure the vehicle performance including wheeled-chassis dynamometer. Components consumed powers, vehicle speed, engine revolution, fuel consumption and consumed energies are all measured in real time and the results are used to verify the numerical modelling work. For optimizing the performance of the vehicle, a rule based control algorithm is proposed and applied to the model using Stateflow environment. Many sequential-decision logic-based rules are graphical coded to operate the internal combustions engine at its most fuel efficient modes.
2017-03-28
Technical Paper
2017-01-1233
Mohamed A. Elshaer, Allan Gale, Chingchi Chen
Abstract Vehicle safety is of paramount importance when it comes to plugging the vehicle into the electric utility grid. The impact of high voltage ground fault has been neglected or, if not, addressed by guidelines extracted from general practices, written in international standards. The agile accretion in Electric Vehicle (EV) development deems an exhaustive study on safety risks pertaining to fault occurrence. While vehicle electrification offers a vital solution to oil scarcity, it is essential that the fast development of the number of electric vehicles on the road does not compromise safety. Meanwhile, the link between technology and demands of society must be governed by vehicle safety. In this paper, a comprehensive study on high voltage (HV) fault conditions occurring in an EV will be conducted. In the next decade, EVs are expected to be prevalent worldwide. Ground fault characteristics are significantly dependent on the earthing system.
2017-03-28
Technical Paper
2017-01-1236
Shuitao Yang, Lihua Chen, Mohammed Khorshed Alam, Fan Xu, Yan Zhou
Abstract A hybrid electric vehicle (HEV) can utilize the electromechanical path to optimize the ICE operation and implement the regenerative brake, the fuel economy of a vehicle therefore gets improved significantly. Bi-directional Boost converter is usually used in an electric drive system to boost the high voltage (HV) battery voltage to a higher dc-link voltage. The main advantages for a system with Boost converter is that the traction inverter is de-coupled from battery voltage variations causing it to be over-sized. When designing this Boost converter, the switching frequency is a key parameter for the converter design. Higher switching frequency will lead to higher switching loss of power device (IGBT +diode), moreover, it has significant impact on inductor ripple current, HV battery ripple current and input capacitor current. Therefore, the switching frequency is one of the most important parameters for the design and selection of both active and passive components.
2017-03-28
Technical Paper
2017-01-1234
Srikanthan Sridharan, Joseph Kimmel, Jun Kikuchi
Abstract Dc-link capacitor sizing considerations are discussed for HEV/EV e-Drive systems. The capacitance value of the dc-link in HEV/EV e-Drive systems affects numerous factors. Some of the most significant are the system stability and the maximum tolerable dc-bus transient voltage with operating point change or with worst-case energy dump into the capacitor. Also requiring attention is the equivalent series resistance and inductance of the capacitor module. The former affects thermal behavior of the capacitor module and the latter affects voltage spikes occurring at every turn-off of a power semiconductor switch. In addition, these factors are dependent on other power-stage component parameters, control structures and controller gains. Also such effects and cross-couplings are operating-point dependent.
2017-03-28
Technical Paper
2017-01-1230
Cyrille Goldstein, Joel Hetrick
Abstract Mechanical losses in electric machines can contribute significantly to overall system losses in an electric drive [1]. With a permanent magnet synchronous machine (PMSM), measuring mechanical losses is difficult without an un-magnetized rotor. Even with an un-magnetized rotor, physical testing can be time consuming and expensive. This paper presents a simple theoretical model of mechanical drag in an electric machine. The model was built using calculations for bearing, seal, and windage drag and was compared to experimental results from testing with un-magnetized motors. Based on this information, the model was modified to better represent the physical system. The goal of this work is to understand the contributors to mechanical drag, to be able to estimate mechanical losses without physical testing, and to be able to quickly evaluate design choices that could reduce mechanical losses.
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
2017-01-1211
SoDuk Lee, Jeff Cherry, Michael Safoutin, Joseph McDonald
Abstract As part of the Midterm Evaluation of the 2017-2025 Light-duty Vehicle Greenhouse Gas Standards, the U.S. Environmental Protection Agency (EPA) developed simulation models for studying the effectiveness of stop-start technology for reducing CO2 emissions from light-duty vehicles. Stop-start technology is widespread in Europe due to high fuel prices and due to stringent EU CO2 emissions standards beginning in 2012. Stop-start has recently appeared as a standard equipment option on high-volume vehicles like the Chevrolet Malibu, Ford Fusion, Chrysler 200, Jeep Cherokee, and Ram 1500 truck. EPA has included stop-start technology in its assessment of CO2-reducing technologies available for compliance with the standards. Simulation and modeling of this technology requires a suitable model of the battery. The introduction of stop-start has stimulated development of 12-volt battery systems capable of providing the enhanced performance and cycle life durability that it requires.
2017-03-28
Technical Paper
2017-01-1214
Jujun Xia, Haifeng Dai, Zechang Sun, Massimo Venturi
Abstract Lithium-ion batteries have been applied in the new energy vehicles more and more widely. The inconsistency of battery cells imposes a lot of difficulties in parameter and state estimations. This paper proposes a new algorithm which can online identify the parameters of each individual battery cell accurately with limited increase of computational cost. An equivalent circuit battery model is founded and based on the RLS (recursive least squares) algorithm, an optimization algorithm with the construction of weight vectors is proposed which can identify the parameters of lithium battery pack considering inconsistency of single battery cell. Firstly, the average value of the parameters of the battery pack is identified with the traditional RLS algorithm. Then the ratios between the parameters of each battery cell can be deduced from the mathematical model of battery. These ratios are used to determine the weight vector of each parameter of individual battery cells.
2017-03-28
Technical Paper
2017-01-1206
Zhihong Jin, Zhenli Zhang, Perry Wyatt
Abstract Power limit estimation of a lithium-ion battery system plays an important balancing role of optimizing the battery design cost, maximizing for power and energy, and protecting the battery from abusive usage to achieve the intended life. The power capability estimation of any given lithium-ion battery system is impacted by the variability of many sources, such as cell and system components resistance, temperature, cell capacity, and real time state of charge and state of health estimation errors. This causes a distribution of power capability among battery packs that are built to the same design specification. We demonstrated that real time power limit estimation can only partially address the system variability due to the errors introduced by itself. Integrating feedback control algorithms with the lithium-ion battery model maximizes the battery power capability, improves the battery robustness to variabilities, and reduces the real time estimation errors.
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
2017-01-1222
Jeongwon Rho, Jeongbin Yim, Daewoong Han, Gubae Kang, Seongyeop Lim
Abstract The current sensor for motor control is one of the main components in inverters for eco-friendly vehicles. Recently, as the higher performance of torque control has become required, the current sensor measurement error and accuracy of motor controls have become more significant. Since the response time of the sensor affects the motor output power, the response delay of the sensor causes measurement errors of the current. Accordingly, the voltage vector changes, and a motor output power deviation occurs. In the case of the large response delay of the sensor, as motor speed increases, then difference between motoring and generating output power becomes larger and larger. This results in the deterioration of power performance in high-speed operation. The deviation of the voltage vector magnitude is the main cause of motor output power deviation and imbalance through the simulation.
2017-03-28
Technical Paper
2017-01-1224
Ryota Kitamoto, Shinnosuke Sato, Hiromichi Nakamura, Atsushi Amano
Abstract A new fuel cell voltage control unit (FCVCU) has been developed for a new fuel cell vehicle (FCV). In order to simultaneously reduce the electric powertrain size and increase the driving motor power, the FCVCU is needed to boost the voltage supplied from the fuel cell (FC) stack to the driving motor. The FCVCU circuit configuration has four single-phase chopper circuits arranged in parallel to form a 4-phase interleaved circuit. The intelligent power module (IPM) is a full SiC IPM, the first known use to date in a mass production vehicle, and efficiency has been enhanced by making use of the effects of the increased frequency to reduce both the size of the unit and the loss from passive parts. In addition, a coupled inductor was used to reduce the inductor size. As a result, the inductor volume per unit power was reduced approximately 30% compared to the previous VCU inductor.
2017-03-28
Technical Paper
2017-01-1259
Eduardo D. Marquez, John Stevenson, Ethan Dietrich, Douglas Nelson, Christopher Flake, Alexander Neblett, Samuel Reinsel
Abstract The Hybrid Electric Vehicle Team of Virginia Tech (HEVT) is currently modeling and bench testing powertrain components for a parallel plug-in hybrid electric vehicle (PHEV). The custom powertrain is being implemented in a 2016 Chevrolet Camaro for the EcoCAR 3 competition. The engine, a General Motors (GM) L83 5.3L V8 with Active Fuel Management (AFM) from a 2014 Silverado, is of particular importance for vehicle integration and functionality. The engine is one of two torque producing components in the powertrain. AFM allows the engine to deactivate four of the eight cylinders which is essential to meet competition goals to reduce petroleum energy use and greenhouse gas emissions. In-vehicle testing is performed with a 2014 Silverado on a closed course to understand the criteria to activate AFM. Parameters required for AFM activation are monitored by recording vehicle CAN bus traffic.
2017-03-28
Technical Paper
2017-01-1318
Prashant Khapane, Suresh Bhosale
Abstract Robustness to sand dune impact is one of the key requirements for Jaguar Land Rover products. Historically off road vehicles were built on a ladder sub frame; and the steel cross beam at the front provided robust protection for the cooling pack. With the move to monocoque construction, the cooling pack became vulnerable to low speed grounding damage. Unfortunately this vulnerability is not confirmed until later in the program when fully representative vehicles are available, which results in late engineering changes that are expensive, time consuming and stressful. Like all late changes it is rarely optimised for cost and weight. With no historic literature or procedure available, the challenge was to model the physics of sand media and also solve the complex multi-physics problem of impact of the whole vehicle with the sand dune.
2017-03-28
Technical Paper
2017-01-1314
Santhoji Katare, Dilip Reddy, Amar Ourchane, Giri Nammalwar
Abstract Virtual Verification (VV) of engineering designs is a critical enabler in the Product Development (PD) process to reduce the time-to-market in a cost efficient manner. Reliance on cost effective VV methods have significantly increased with increased pressure to meet customer expectations for new products at reduced PD budgets. Computer Aided Engineering (CAE) is one such VV method that affords an engineer to make decisions about the ability of the designs to meet the design criteria even before a prototype is built. The first step of the CAE process is meshing which is a time consuming, manual and laborious process. Also mesh development time and accuracy significantly varies with the (1) component (trim body, engine, suspension, brakes, etc.), (2) features predominantly occurring in the component (welds, ribs, fillets, etc.), meshing guidelines based on which the model needs to be developed (durability, safety, NVH, etc.), and the expertise of the meshing engineer involved.
2017-03-28
Technical Paper
2017-01-1317
Luis Felipe Blas Martinez, Rodolfo Palma, Francisco Gomez, Dhaval Vaishnav, Francisco Canales
Abstract Liquid sloshing is an important issue in ground transportation, aerospace and automotive applications. Effects of sloshing in a moving liquid container can cause various issues related to vehicle stability, safety, component fatigue, audible noise and, liquid level measurement. The sloshing phenomenon is a highly nonlinear oscillatory movement of the free-surface of liquid inside a container under the effect of continuous or momentarily excitation forces. These excitation forces can result from sudden acceleration, braking, sharp turning or pitching motions. The sloshing waves generated by the excitation forces can impact on the tank surface and cause additional vibrations. For the loads with the frequencies between 2 to 200 Hz, the structural fatigue failure is a major concern for automotive applications.
2017-03-28
Technical Paper
2017-01-1250
Tomokazu Ishikawa, Kouhei Ikebuchi, Kenji Nakamura, Osamu Ichinokura, Naoki Kurimoto, Yoshiaki Nishijima
Abstract An electromagnetic and motion-coupled analysis is made for a Switched Reluctance Motor (SRM) based on a Reluctance Network Analysis (RNA). A full-pitch-winding SRM is promising since it has a high torque density. Since the motor characteristics such as driving torque significantly depend on commutation pattern, an analysis coupled with motor motion and its drive circuit is requisite for the performance prediction. However, in the full-pitch-winding SRM, the relationship between the coil magnetomotive force and the core flux is complicated, and thus Finite Element Method (FEM) has been major method to predict the motor characteristics, which takes too much computational time for cycle calculations. An RNA treats the relationship of coil magnetomotive force and core flux as lumped parameter circuit, and thus enables fast computation with a macroscopic view of magnetic phenomena.
2017-03-28
Technical Paper
2017-01-1255
Zhihong Wu, Ke lu, Yuan Zhu, Xiaojun Lei, Liqing Duan, Jian_ning Zhao
Abstract Permanent magnet synchronous motors (PMSM) are widely used in the electric vehicles for their high power density and high energy efficiency. And the motor control system for electric vehicles is one of the most critical safety related systems in electric vehicles, because potential failures of this system can lead to serious harm to humans’ body, so normally a high automotive safety integrity level (ASIL) will be assigned to this system. In this paper, an ASIL-C motor control system based on a multicore microcontroller is presented. At the same time, due to the increasing number of connectivity on the vehicle, secure onboard communication conformed to the AUTOSAR standard is also implemented in the system to prevent external attacks.
2017-03-28
Technical Paper
2017-01-0686
Mohammed Jaasim Mubarak Ali, Francisco Hernandez Perez, S. Vedharaj, R. Vallinayagam, Robert Dibble, Hong Im
Abstract Pre-ignition in SI engine is a critical issue that needs addressing as it may lead to super knock event. It is widely accepted that pre-ignition event emanates from hot spot(s) that can be anywhere inside the combustion chamber. The location and timing of hotspot is expected to influence the knock intensity from a pre-ignition event. In this study, we study the effect of location and timing of hot spot inside the combustion chamber using numerical simulations. The simulation is performed using a three-dimensional computational fluid dynamics (CFD) code, CONVERGE™. We simulate 3-D engine geometry coupled with chemistry, turbulence and moving structures (valves, piston). G-equation model for flame tracking coupled with multi-zone model is utilized to capture auto-ignition (knock) and solve gas phase kinetics. A parametric study on the effect of hot spot timing and location inside the combustion chamber is performed.
2017-03-28
Technical Paper
2017-01-0839
Luigi Allocca, Alessandro Montanaro, Amedeo Amoresano, Giuseppe Langella, Vincenzo Niola, Giuseppe Quaremba
Abstract The paper reports an innovative method of analysis based on an advanced statistical techniques applied to images captured by a high-speed camera that allows highlighting phenomena and anomalies hardly detectable by conventional optical diagnostic techniques. The images, previously elaborated by neural network tools in order for clearly identifying the contours, have been analyzed in their time evolution as pseudo-chaotic variables that may have internal periodic components. In addition to the Fourier analysis, tools as Lyapunov and Hurst exponents and average Kω permitted to detect the chaos level of the signals. The use of this technique has permitted to distinguish periodic oscillations from chaotic variations and to detect those parameters that actually determine the spray behavior.
2017-03-28
Technical Paper
2017-01-0829
Gina M. Magnotti, Caroline L. Genzale
Abstract The atomization and initial spray formation processes in direct injection engines are not well understood due to the experimental and computational challenges associated with resolving these processes. Although different physical mechanisms, such as aerodynamic-induced instabilities and nozzle-generated turbulence and cavitation, have been proposed in the literature to describe these processes, direct validation of the theoretical basis of these models under engine-relevant conditions has not been possible to date. Recent developments in droplet sizing measurement techniques offer a new opportunity to evaluate droplet size distributions formed in the central and peripheral regions of the spray. There is therefore a need to understand how these measurements might be utilized to validate unobservable physics in the near nozzle-region.
2017-03-28
Technical Paper
2017-01-0828
Dongwei Wu, Baigang Sun, Dan Xu, Xiaodong An, Yunshan Ge
Abstract The pressure fluctuation characteristics of a constant pressure fuel system has great influence on its fuel injection characteristics. It is, therefore important to understand the impacts of these fluctuations in order to better study and optimize the fuel injection characteristics. In this study, the pressure fluctuation characteristics of the high pressure common rail system have been investigated experimentally. The transient pressure at different positions in the high pressure common rail system have been measured. The phase of pressure fluctuation during the injection process has been analyzed and the corresponding fluctuating characteristic parameters have been characterized for each phase. The changes in pressure wave propagation velocity, fuel injection pressure drop amplitude, wave amplitude, period and decay time are obtained by studying the fluctuation characteristic parameters caused by fuel pressure and temperature change.
Viewing 91 to 120 of 33097