Criteria

Display:

Results

Viewing 1 to 30 of 29953
2015-04-14
Technical Paper
2015-01-1132
Jiaxing Zhan, Mohammad Fard
Preventing the backdriving and controlling the position stability of gearbox are critical tasks in some precision machineries and instruments. Consequently, many self-locking mechanisms have been developed to stabilize the rotation accuracy in gearing system. However, these assistant devices could enlarge the volume of gearbox, increase the complexity of transmission system and introduce more errors between gear pairs. Therefore, alternative methods are required to achieve design requirement without adding any extra electric or mechanical device. As a novel gear designed with anti-backdriving capacity, the self-locking gear has been of great interest to researchers and engineers to date. The self-locking gear can be used to prevent either the inertia driving, or backdriving, or both, when the driving torque is suddenly reduced as a result of power off, torsional vibration, power outage, or any mechanical failure at the transmission input side.
2015-04-14
Technical Paper
2015-01-0217
William Buller, Rini Sherony, Brian Wilson, Michelle Wienert
To reduce the number and severity of accidents, automakers have invested in active safety systems to detect and track neighboring vehicles to prevent accidents. These systems often employ RADAR and LIDAR, which are not degraded by low lighting conditions. In this research effort, reflections from deer were measured using two sensors often employed in automotive active safety systems. Based on a total estimate of one million deer-vehicle collisions per year in the United States, the estimated cost is calculated to be $8,388,000,000 [1]. The majority of crashes occurs at dawn and dusk in the Fall and Spring [2]. The data includes tens of thousands of RADAR and LIDAR measurements of white-tail deer. The RADAR operates from 76.2 to 76.8 GHz. The LIDAR is a time-of-flight device operating at 905 nm. The measurements capture the deer in many aspects: standing alone, feeding, walking, running, does with fawns, deer grooming each other and gathered in large groups.
2015-04-14
Technical Paper
2015-01-0433
Zeyu Ma, James Yang, Ming Jiang, Yunqing Zhang
A new recursive method is presented for real-time estimating the inertial parameters of a vehicle using the well-known Two-Degree-of-Freedom (2DOF) bicycle car model. The recursive state and parameter estimation is built on the framework of polynomial chaos theory and maximum likelihood estimation. Then the most likely value of both the mass and yaw mass moments of inertial can be obtained with the numerical simulations of yaw velocity. To work with a realistic set of measurements, several levels of measurement noise are exerted to the simulation results of yaw velocity. The estimation values indicate that the proposed method remains robust against the measurement noise together with high convergence speed and accuracy. The proposed novel method will also be useful for a broad range of estimation problems.
2015-04-14
Technical Paper
2015-01-1373
Yulong Lei, Hui Tang, Xingjun Hu, Ge Lin, Bin Song
With the continuous improvement of the road condition, commercial vehicles get to be faster and more overloaded than before, which puts higher pressure on the vehicle braking system. Conventional friction braking has been difficult to meet the needs of high-power commercial vehicle. The auxiliary brake equipment will become the future trend for commercial vehicle. Hydraulic retarder is superior secondary braking equipment. Previously hydraulic retarder research mainly focus on flow field analysis, the braking torque calculation, cascade system optimization and control methods for hydraulic retarder. The gas-liquid two-phase flow in working chamber is less researched. Based on this, this article discusses on the hydraulic retarder from two aspects, including CFD numerical modeling method, transient characteristics of oil-filling , which provides support for hydraulic retarder design and matching in the vehicle. The main contents and conclusions are as follows: 1.
2015-04-14
Technical Paper
2015-01-0608
Gang Tang, Hengjia Zhu, Yunqing Zhang, Ying Sun
The vehicle ride comfort behavior is closely associated with the vibration isolation system such as the primary suspension system, the engine mounting system, the cab suspension system and the seat suspension system. Air spring is widely used in the cab suspension system for its low vibration transmissibility, variable spring rate and inexpensive automatic leveling. The mathematical model of the pneumatic system including the air spring, the leveling valve and the pipe is presented. The frequency dependency of the air spring’s stiffness characteristic is highlighted. The air spring dynamic model is validated by comparing the results of the experiments and the simulation. The co-simulation method using ADAMS and AMESim is applied to integrate the pneumatic system into the cab multi-body dynamic model. The simulation and ride comfort test results under random excitation are compared.
2015-04-14
Technical Paper
2015-01-0442
Sudhi Uppuluri, Ajay Naiknaware
Abstract: With increasing pressure to meet CAFE standards, various strategies are being developed to actively manage the vehicle drag and engine thermal performance to squeeze out additional fuel economy performance from existing vehicle. This paper develops on the previous work presented at this conference and discusses the sensitivity of key vehicle parameters that affect the engine thermal performance and fuel economy of the vehicle. The sensitivity analysis is based on a vehicle level system model that captures the entire engine thermal model and transient behavior of various key components such as the thermostat, the active grill shutter and accessory loads. Results discussed in this paper provides guidance on which variables have the most affect on fuel economy and which variables must be tightly controlled to improve the robustness and stability of the design.
2015-04-14
Technical Paper
2015-01-0803
Marko Jeftić, Jimi Tjong, Graham Reader, Meiping Wang, Ming Zheng
Experimental testing was done with a modern compression ignition engine to study the effect of the engine load and the effect of different fuels on the post injection characteristics. Two different fuels were utilized; ultra-low sulphur diesel and n-butanol. The results showed that a post injection can be an effective method for increasing the operating range of the engine load. Engine operation at high load can be limited by the peak cylinder pressure but the test results showed that an early post injection can increase the engine load without increasing the peak in-cylinder pressure. Neat butanol combustion may have a very high peak in-cylinder pressure and a very high peak pressure rise rate even at low load conditions. The test results showed that a butanol post injection can contribute to engine power without significantly affecting the peak pressure rise rate and the peak in-cylinder pressure.
2015-04-14
Technical Paper
2015-01-0192
Yukihide Niimi, Toshinori Matsui, Naoya Tsuchiya
Vehicle electronics system will continue to become more complex and larger in scale, and because of this the development is conducted without control. As a result, in system development in reality, things are intertwined with each other, like spaghetti. This has made it extremely difficult to develop the entire electronics system coherently and efficiently from the functional architecture down to physical architecture. So, we have to reform the R&D style of the electronics field to a style which will continuously and efficiently generate high-quality products. This will be achieved by dividing development into functions and components. The development of functions OEMs want to equip in the vehicles, that is, "what to make," and the components development, that is, "how to realize them."  For this activity, it is necessary to promote and accelerate the platform-based development looking down at the entire electronics systems.
2015-04-14
Technical Paper
2015-01-0669
Nagarjun Jawahar, Saharash Khare
Automotive OEM’s are looking for innovative solutions to capture the possible failure due to warpage and shrinkage of an insert molded part through virtual simulations with help of FEA tools, thereby saving the mold cost, material cost and time. This work demonstrates an approach to study and simulate the failure of an insert molded part which happened after few days of the part molding under idle condition. To simulate the above failure, an innovative approach coupling Moldflow and Abaqus software was derived. First, a flow simulation including phase change of plastic material was carried out with derived parameters, results of which were exported as input to the Abaqus structural solver. Secondly, a thermo-mechanical analysis of the model was then carried out considering the thermal and moisture effect on material property. A good correlation was achieved between the actual failure location and max stress location as predicted by said coupled approach.
2015-04-14
Technical Paper
2015-01-1235
Kevin L. Snyder, Jerry Ku
The Wayne State University (WSU) EcoCAR2 student team converted a 2013 Chevrolet Malibu into a plug-in parallel hybrid for their participation in the EcoCAR2 design competition. EcoCAR2 was a three-year Department of Energy (DoE) Advanced Vehicle Technical Competition (AVTC) for 15 select university student teams competing on designing, building, and then optimizing their different plug-in hybrid reengineering of GM donated vehicles. WSU’s Parallel Through The Road (PTTR) powertrain design provides 49 km (30 miles) of electric driving using a rear axle mounted traction motor before the front axle mounted ethanol (E85) Internal Combustion Engine (ICE) powertrain is needed. This design allows the vehicle to operate the traction motor and ICE independently for increased reliability and also together: for increased fuel economy or increased dynamic performance.
2015-04-14
Technical Paper
2015-01-1375
James Price
Compressed development cycles drive increased focus on virtual development, including both functional verification and quantitative simulation of electrical system designs. However, one hurdle often cited is the effort needed to develop behavioral models of electrical components such as wires, fuses, and ECUs. This presentation shows that it is fully possible to obtain reliable and surprisingly accurate results using the simplest of models. By placing these models in a re-usable library and providing a simple, visual interaction environment, early design debugging using a computer becomes possible for every electrical engineer.
2015-04-14
Technical Paper
2015-01-0486
Jamshid Mohammadi, Mehdi Modares
Performance data offers a powerful tool for system condition assessment and health monitoring. In most applications, a host of various types of sensors is employed and data on key parameters (describing the system performance) is compiled for further analysis and evaluation. In ensuring the adequacy of the data acquisition process, two important questions arise: (1) is the complied data robust and reasonable in representing the system parameters; and (2) is the duration of data acquisition adequate to capture a favorable percentage (say for example 90%) of the critical values of a given system parameter? The issue related to the robustness and reasonableness of data can be addressed through known values for key parameters of the system. This is the information that is not often available. And as such, methods based on trends in a given system parameter, expected norms, the parameter’s relation with other known parameters, and simulations can be used to assure the quality of the data.
2015-04-14
Technical Paper
2015-01-0673
Rohit Ray, Nagarjun Jawahar
Automotive OEM’s are looking to develop plastic parts with maximum life and durability through virtual simulations with help of CAE tools, thereby saving the mold cost, material cost and time. The design constrains would be manufacturability, loads, boundary condition and aesthetics. This work involves the multi-discipline approach to virtually visualize the effect of fluid structure interaction due to splashing on the rear fender of a motorcycle which acts as mud guard. This study shows effect of splashing of water over rear fender on wet roads. First, the pressure developed on the rear fender due to impingement of water on surface is obtained through a multiphase volume of fluid analysis using CFD software Fluent. Secondly, these pressure values are taken as input in Abaqus software and the part is analyzed for its durability along with road excitations.
2015-04-14
Technical Paper
2015-01-1121
Enrico Galvagno, Mauro Velardocchia, Alessandro Vigliani, Antonio Tota
In this paper the torsional dynamic behaviour of a Dual Mass Flywheel is investigated both experimentally and numerically. The study presents a mathematical description of the system both in time and frequency domain, using lumped parameter models. Concerning the frequency domain analysis, two types of excitation are applied and compared: sine sweep excitation (with different directions) and steady-state sinusoidal excitation. A square wave excitation is used to stimulate the model and the real system in the time domain. The unknown damping parameter has been identified and a sensitivity analysis is presented. Good correspondence between experimental and numerical results has been found.
2015-04-14
Technical Paper
2015-01-1243
Michal Pasternak, Fabian Mauss, Fabio Xavier, Michael Rieß, Marc Sens, Andreas Benz
Numerical simulations, based on zero-dimensional (0D) and three-dimensional (3D) engine models, have been carried out to analyze the impact of multi spark-plug technology on combustion process in a gasoline engine. The 3D computational fluid dynamics (CFD) cold flow simulations were carried out to characterize the in-cylinder flow in terms of the occurring time and length scales. This information was used as an input for 0D simulations that focused on the combustion processes. The 0D simulations were carried out using a stochastic reactor model for spark ignition engines (SI-SRM), which is built on a probability density function (PDF) approach. The quasi-three dimensional treatment of the combustion chamber geometry by the 0D SI-SRM, and detailed chemistry consideration, enabled to investigate the impact of the 3D character of the flame propagation, and the number of spark-plugs and their location on the combustion progress, completeness, and access the risk of knock occurrence.
2015-04-14
Technical Paper
2015-01-1738
Dileep Namdeorao Malkhede, Hemant Khalane
Due to reciprocating nature of IC engine, flow physics in intake manifold is complex and has significant effect on volumetric efficiency. Variable length intake manifold technology offers potential for improving engine performance. This paper therefore investigated effect of intake length on volumetric efficiency for wider range of engine speeds. For this purpose 1-D thermodynamic engine model of a single cylinder 611cc standard CFR engine capable of predicting pressure pulsations in the intake was developed. For validation, pressure pulsations were predicted at two different locations on intake manifold and compared against test data. This model was used to predict volumetric efficiency for different intake lengths and engine speeds. Volumetric efficiency was found to be a function of both engine speed and intake length, more so at higher engine speeds. FFT analysis of intake pressure pulsations during suction stroke and intake valve closed phase was carried out separately.
2015-04-14
Technical Paper
2015-01-1751
Feng Yan, Wanhua Su
A theoretical–numerical analysis on the roles of initial charge temperature (Tin), initial pressure (Pin), equivalent ratio (Ф) and oxygen concentration ([O2]) on exergy loss events of n-heptane adiabatic constant volume combustion process by detailed chemical kinetics were explored in aspect of overall exergy loss rates, exergy loss rates of individual reactions, and loss distributions. The analysis is based on computing the various entropy generation terms among detailed kinetics controlled chemical reactions. Three apparent peaks of the overall exergy loss rate are observed so that the combustion process is classified as: Stage 1 (the process of large molecule fuels -> small molecule fuels), Stage 2 (the process of small molecule fuels -> H2O2 loop reactions -> CO) and Stage 3 (the oxidation processes of CO, H, and O to final products of CO2 and H2O).
2015-04-14
Technical Paper
2015-01-1698
Balamurugan Rathinam, Frederic Ravet, Cedric Servant, Laurent Delahaye, Upendra Naithani
Optimising the in-cylinder aerodynamics in Spark ignition (SI) engines is one of the most important contribution to improve the combustion efficiency and thus to save the fuel consumption and to limit CO and unburnt hydrocarbon emissions. The tumble motion originated near the Top Dead Centre (TDC) known as “Tumble Squeeze” is responsible for higher level of turbulence which is necessary to increase the turbulent flame velocity. Higher the flame velocity is, higher the combustion efficiency is. Experiments are conducted in an optical engine and the velocity fields are measured with the aid of advanced particle image velocimetry (PIV) measurement technique. The velocity fields are computed through simulation and compared with measurements. Then, the turbulence kinetic energy is also calculated from the velocity fields which are basically not possible to measure from the experiments. This study is performed for three different operating points with low and high tumble configurations.
2015-04-14
Technical Paper
2015-01-1493
Vinay L. Virupaksha, Stuart Brown
Research Council for Automotive Repairs (RCAR) has developed a bumper test at 10.5 km/h to assess the damageability and repairing cost during a low speed collusion. For minimum damage and minimum repairing cost during low speed collusion it is necessary to design a bumper beam which provides structural stiffness and reduced deflection. Often it is challenging to design a front bumper beam to meet all safety requirements including, RCAR, high speed offset barrier and pedestrian protection, since these requirements are not necessarily compatible with each other. Design changes in rails and packaging constraints add to this challenge. In this study, design of six sigma and finite element analysis is used to study the parameters that affect the stiffness and deflection of the front bumper beam.
2015-04-14
Technical Paper
2015-01-0590
Dae-Un Sung, Young Hyun Ryu, Soon Cheol Park
Recently, many kinds of new technology systems are adapted to a new developing vehicle. However the field usage information of a new technology system could not be easily obtained because this system has not been used by customers. It is not easy to evaluate the reliability and durability of these kinds of new systems. In this research, the durability test mode of AFLS (Adaptive Front Lightning System) with LED (Light Emitting Diode) lamp has been developed. First of all, The failure modes were analyzed by considering failure mechanism for each component. The thermal load, vibration, swiveling movement and electrical loads were investigated. The RLDA (Road Load Data Acquisition) technique was used for obtaining the vibration and temperature of LED AFLS in proving ground. The vibration test mode was developed by PSD (Power Spectral Density). The thermal load effect on life time of LED was investigated.
2015-04-14
Technical Paper
2015-01-1228
Zhuoran Zhang, Miriam Di Russo, Xianfeng Yan, Ahmed I. Uddin, Dhanya Sankaran, Jerry C. Ku
This paper presents the work performed by the Wayne State University (WSU) EcoCAR 3 student design competition team in its preparation for the hybrid electric vehicle architecture selection process. This process is recognized as one of the most pivotal steps in the EcoCAR 3 competition. With a key lesson learned from participation in EcoCAR 2 on “truly learning how to learn,” the team held additional training sessions on architecture selection tools and exercises with the goal of improving both fundamental and procedural skills. The work conducted represents a combination of the architecture feasibility study and final selection process in terms of content and procedure, respectively. At the end of this study the team was able to identify four potentially viable hybrid powertrain architectures, and thoroughly analyze the performance and packaging feasibility of various component options.
2015-04-14
Technical Paper
2015-01-1231
Eli H. White, Douglas J. Nelson, P. Christopher Manning
Throughout the past several years, a major push has been made for the automotive industry to provide vehicles with lower environmental impacts while maintaining safety, performance, and overall appeal. Various legislation has been put into place to establish guidelines for these improvements and serve as a challenge for automakers all over the world. In light of these changes, hybrid technologies have been growing immensely on the market today as customers are seeing the benefits with lower fuel consumption and higher efficiency vehicles. With the need for hybrids rising, it is vital for the engineers of this age to understand the importance of advanced vehicle technologies and learn how and why these vehicles can change the world as we know it. To help in the education process, this paper seeks to define a powertrain model created and developed to help users understand the basics behind hybrid vehicles and the effects of these advanced technologies.
2015-04-14
Technical Paper
2015-01-0627
Xiaoguang Yang, Oluremi Olatunbosun, Daniel Garcia-Pozuelo, Emmanuel Bolarinwa
The development of intelligent tyre technology from concept to application covers multi-disciplinary fields. During its development course, computational method has a significant effect on understanding tyre behaviour, assisting design of intelligent tyre prototype system and developing tyre parameters estimation algorithm, etc. In this paper, finite element tyre model was adopted for developing strain-based intelligent tyre system. The finite element tyre model was created considering tyre composite structure and nonlinear material properties, which was also validated by fundamental test. It is used to study tyre strain characteristics by steady state simulation for straight line rolling, traction and braking, and cornering rolling. Tyre loading conditions were estimated by feature extraction and data fitting. This process forms the fundamentals for identifying tyre loadings from strain information on potential sensor locations.
2015-04-14
Technical Paper
2015-01-0626
Adam C. Reid, Moustafa El-Gindy, Fredrik Oijer, David Philipps
The purpose of this research paper is to outline the methodology and procedure used for the development of a wide base rigid ring tire model. A rigid ring model is a mechanical representation of a tire model in which its in-plane and out-of-plane characteristics and behaviour can be captured. The FEA construction of the tire model is first completed to match all known information regarding the physical dimensions and material properties of the tire. For information that is unknown, an optimization-based parameter tuning algorithm is then run in order to solve for said parameters while matching any experimental data that is supplied. A series of virtual experiments are then conducted which replicate laboratory tests as well as some high speed maneuvers in order to isolate for specific tire dynamic parameters.
2015-04-14
Technical Paper
2015-01-0242
Nick Smith
Correct by construction design processes can be dramatically enhanced using simulation techniques, especially early in the design process. But simulation is too often the preserve of specialist staff, who may work disconnected from day-to-day design updates. This paper highlights simulation and analysis tools that can be used by every electrical engineer, addressing topics ranging from functional verification to component sizing to failure modes & effects analysis. Furthermore, valuable results can be obtained with the simplest of models; and the models themselves can mature as the organization's use of simulation matures.
2015-04-14
Technical Paper
2015-01-1717
Li-Chun Chien, Matthew Younkins, Mark Wilcutts
Dynamic skip fire is a control method for internal combustion engines in which engine cylinders are selectively fired or skipped to meet driver torque demand. Each cylinder is operated at or near its best thermal efficiency and flexible control of acoustic and vibrational excitations is achieved. In this type of engine operation, fueling, and possibly intake and exhaust valves of each cylinder are actuated on an individual firing opportunity basis. The implementation and benefits of this system have been described in several previous papers. This paper describes engine thermofluid modeling for this type of operation for purposes of air flow and torque prediction. Airflow dynamic and thermodynamic results for skip fire engine operation are presented and compared with experimental data under several different firing sequences. Unique impacts of dynamic skip fire on air estimation, and performance parameters are discussed.
2015-04-14
Technical Paper
2015-01-0693
Tadashi Naito, Yuta Urushiyama, Michael Bruyneel
Carbon Fiber Reinforced Plastic (CFRP) composite material has more strength and stiffness than steel. FEM analysis of coupon test specimens were performed which are accompanied by intra-ply fracture, applying damage model. This model considers the damage evaluation for different fracture modes, stiffness degradation due to the damage, and coupling between different damage modes. The intra-ply damage is divided into three modes; fiber direction damage which represents fiber fracture, and damages in transverse and shear direction with respect to fiber, which arise from resin fractures. Each damage mode is represented by function of thermodynamic force which has the same dimension as strain energy. Damages in transverse and shear directions are coupled by coupling factor and thermodynamic forces. Permanent deformation of resin and non-linearity of the fiber modulus are also considered.
2015-04-14
Technical Paper
2015-01-0705
Koichi Taniguchi, Hiroshi Matsuda, Rinsei Ikeda, Kenji Oi
High joint strength of resistance spot welds is necessary for high rigidity and reliability of car body using ultra high strength steel (UHSS) sheets with tensile strength over 980MPa. We developed “pulsed current pattern” consisting the combination of short cool time and short-time high-current post-heating. This new process can achieve high cross tension strength (CTS) with sufficient tensile shear strength (TSS) in shorter welding time than conventional temper pattern. This paper presents the heating pattern and the effect on the joint strength by pulsed current pattern. Finite element analysis (FEA) for post-heating patterns was conducted using SORPAS. Temperature dependent material properties of 1180MPa grade steel were taken into account. FEA shows that the short-time high-current post-heating leads to rapid heating in nugget and heat affected zone (HAZ) compared to conventional temper pattern consisting long-time low-current post-heating.
2015-04-14
Technical Paper
2015-01-1693
Mark Allen, Graham Hargrave, Petros Efthymiou, Viv Page, Jean-Yves Tillier, Chris Holt
It is an engineering requirement that gases entrained in the coolant flow of an engine must be removed to retain cooling performance, while retaining a volume of gas in the header tank for thermal expansion and pressure control. The main gases present are air from filling the system, exhaust emissions from leakage across the head gasket, and also coolant vapour. These gases reduce the performance of the coolant pump and lower the heat transfer coefficient of the fluid. This is due to the reduction in the mass fraction of liquid coolant and the change in fluid turbulence. The aim of the research work contained within this paper was to analyse an existing phase separator using CFD and physical testing to assist in the design of an efficient phase separator.
2015-04-14
Technical Paper
2015-01-0195
Satishchandra C. Wani
Bonds wires in automotive electronics modules are used to carry current from external harness to components on PCB. They are very thin wires (few µm) made up of gold, aluminum or copper and have to undergo mechanical reliability to withstand extreme mechanical and thermal loads under vehicle operation. Thermal reliability of bond wire is to make sure that it can withstand prescribed electric current under given external boundary conditions without fusing retaining electronic module functionality. While carrying current, wire bond material by nature offers electric resistance that is converted to heat, joule heating, is proportional to current flow and electrical resistance. For constant current flow, electrical resistance is proportional to wire material resistivity, length and inversely proportional to cross sectional area available for current flow. The resistivity of wire increases with temperature thus leading to thermal runaway situation if not handled properly.
Viewing 1 to 30 of 29953