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Viewing 1 to 30 of 207
2016-04-05
Technical Paper
2016-01-0492
Bokyung Kim
The downsizing technology of engines is increasingly applied to the automotive since it is more important to decrease the emission of CO2 and the energy consumption. The engine parts are requested to enhance heat-resistance to apply the high performance engine. This study presents new coating materials composed of nano-meter grains with CrN, Cr and Cu functioning low-friction, anti-wear and heat resistance. The coatings were synthesized by hybrid PVD including metal arc source, magentron sputter source and ion-gun source. Although Cu has low hardness (~0.3GPa), the hardness of Cr-Cu-N is not declined because it was composed of below 20nm sized grains (Cu, CrN, Cr) Cr-Cu-N had lower friction than CrN owing to Cu’s low shear strength. Cr-Cu-N films optimized using RSM showed the excellent tribological behavior and low COF compared with DLC. The tribological properties of the Cr-Cu-N demostrated superior wear resistance and low friction at normal and severe temperature conditions.
2016-04-05
Technical Paper
2016-01-0508
Hyung Seok KIM
This study provides a tire puncture sealant including NR latex and acrylic emenrseion, which has a reduced viscosity at -40℃, and is also exellent storage stability at -40℃ to 70℃, initial sealaing performance. Also, this study provides device for sealaing inflatable objects. 'One- Piece Tire Repair Kit' can reduced weight and operation steps.
2016-04-05
Technical Paper
2016-01-1236
Jun Yeon PARK, Hojoong Lee
One of the ways to improve the fuel efficiency of the Hybrid and Electric Vehicle is to optimize electric system. Since power system for auxiliary equipments in vehicles such as lighting, audio and A/C cooling fan is based on 12V system, optimizing the LDC (Low voltage DC-DC- Converter) system, transform the voltage from High voltage DC (200-300V) to Low voltage DC (12V), it has become a key issue in Hybrid and Electric Vehicle. In order to achieve these goals, the LDC variable voltage control based on the ADAS (Advanced Driver Assistance System) map is carried out to predict charge-discharge behaviors of a 12V lead-acid battery during driving and to increase charging efficiency. In the present study, feedback control system for 12V battery charging and discharging is designed to compromise between the 12V battery SOC (State of Charge) and driving conditions at different traffic points.
2016-04-05
Technical Paper
2016-01-1112
Byeong wook Jeon, Sang-Hwan Kim, Donghoon Jeong, Joseph Young-il Chang
In general, driving performance development of a vehicle is focused on satisfying preference of average customers. But there is no single standardized setup which can fulfill various driving tastes of all drivers, since they are different by gender, culture, age group, and personal habits. To resolve this issue, automotive companies have introduced selectable drive mode buttons which drivers can manually select desired drive mode among Normal, Eco, and Sport. These manually selected multi-mode systems provides variety of choices than single-mode system, but it still is a transitory solution which induces inconvenience of requiring drivers' effort to select and frequently change preferred drive mode in volatile driving situations. Also, it is a questionable supposition that categorizing complex needs of drivers into 3 modes is sufficient.
2016-04-05
Technical Paper
2016-01-1114
Jinsung Kim
A dry clutch is vulnerable to judder phenomenon which is caused by variations in the vehicle load condition and frictional material properties. Such a problem may lead to the stick-slip limit cycle that results in undesired longitudinal vibrations of vehicles. The amplitude of vibrations is detected by the signal conditioning from the measurements with the transmission input shaft spend and the wheel speed sensors. Based upon this, a perturbation is applied additionally on the nominal launch controller to make the drive shaft oscillation vanish. It can be achieved by the control design without any extra hardware cost. Finally, experimental results confirm the effectiveness of the proposed mechanism.
2016-04-05
Technical Paper
2016-01-1294
Jonggyu KIM, Pyoung Beom Kim, YoungChan Lee, Sunghee Jung, Byeong-Ug Choi
This paper presents the characteristics of a 3 Cylinder CVT vehicle and a process to improve fuel economy and reduce noise and vibration. To increase the lock-up area of damper clutch for the high fuel economy and to decrease booming and vibration affected by lock-up, chassis systems of a driveline and structure resonance characteristics are studied by experiment and simulation. CVT software calibration parameters are optimized for fuel economy and NVH. With This Study, the lock-up area has been increased by 300RPM and the fuel economy has been improved by approximately 1%, while the NVH characteristic is almost same.
2016-04-05
Technical Paper
2016-01-1098
Jongsool Park
The market demands for CO2 reduction and fuel economy have led to a variety of new gear set concepts of automatic transmissions with 4 planetary gear sets and 6 shift elements in recent years. Understanding the relationship between the torque of clutch and brake and gear ratio in the design stage is very important to assess new gear set concepts and to set up the control strategy for enhancing shift quality and to reduce the heat generation of clutch and brake. In this paper, a new system approach is used to unify the relationship between torque and gear ratio during the gear shift for all multi-step planetary automatic transmissions.
2016-04-05
Journal Article
2016-01-0515
Jee Young Youn, Seok Hwan Kim, Yong Sun (Steven) Jin
The increased demand to reduce weight is forcing automotive industry to replace some metal under hood components with plastic materials. Parts such as engine cylinder head cover, air intake manifold was already replaced from metal to plastic. In recently Parts which is located in the underbody parts like engine and transmission oil pans is developing as a plastic material. In this case, impact resistance performance is very important to have reliability against splatting of rocks or impact of hump. In this research, Impact resistance of plastic underbody parts was studied using simulated plastic injection molding specimen which is able to test as type of material, foaming method (position and number of injection molding gate), and feature of ribs. Applied material was glass fiber reinforced polyamide which is able to apply for underbody part. Test was performed as several combination of injection molding gate and rib type.
2016-04-05
Journal Article
2016-01-1569
Kiho Yum
In this research, the influence of tire force and moment (F&M) characteristics on vehicle on-center steering performance was analyzed and then how to improve vehicle on-center performance was studied through controlling tire structure design parameter and tire tread grip characteristics. First, the relationship between vehicle on-center steering performance and tire F&M characteristics was identified by comparing vehicle steering measurement and tire F&M measurement. It was found that on-center steering performance is improved as the aligning torque at slip angle 1° increases. Secondly the influence of tire structure design parameter on tire aligning torque was studied by tire F&M finite element analysis. It was also found aligning torque increases as tire tread and sidewall stiffness decreases. However it shows trade-off characteristics with tire cornering force stiffness so it is necessary to optimize cornering force stiffness and aligning torque stiffness.
2016-04-05
Journal Article
2016-01-1122
Hyungsouk Kang, TaeYoung Chung, Hyeongcheol Lee, Hyungbin Ihm
Booming noise can be heard at specific engine speed when driving. Engine’s combustion pressure variation generates crankshaft vibration and it is transferred through the driveline. Driveline vibration is delivered to the vehicle body and cause the body components vibrate. This is how booming noise is occurred. HMC(Hyundai Motor Company)’s TMED(Transmission Mounted Electric Device) type HEV has a weakness in booming noise due to increased weight caused by additional hybrid customized parts and absence of torque converter. To overcome the weakness some works are needed such as lowering torsion-damper stiffness, adding dynamic dampers and moving engine operation point from the optimized point. But it has consideration such as increased cost and sacrificed fuel economy. In this study, a method of reducing lock-up booming noise at low engine speed of HEV is introduced.
2016-04-05
Technical Paper
2016-01-1029
Jinsuk Kang, Byungchan Lee, Dohoy Jung
Charge boosting strategy plays an essential role in improving the power density of diesel engines while meeting stringent emissions regulations. Especially in downsized two-stage turbocharged engines turbocharger matching is very challenging and critical to achieve desired boost pressure while maintaining sufficiently fast transient response. A numerical simulation model is developed to evaluate the effect of two-stage turbocharger configurations on the perceived vehicle acceleration in a virtual experimental environment. An engine system model is developed in GT-SUITE and model-based turbocharger control logic is developed in MATLAB using an analytical compressor model and a mean-value engine model as observers. The compressor model computes pressure ratio in each stage based on the compressor rotational speeds, and uses the information to estimate the turbine operation.
2016-04-05
Technical Paper
2016-01-1184
Kyoung-Ku Ha, Chang Ha Lee, Chi Myung Kim, Sae Hoon Kim, Byung Ki Ahn
The subject of this study is a centrifugal compressor for fuel cell electric vehicles (FCEV). Recently there is a growing interest in FCEV since it considered as a realistic solutions to environmental regulations for passenger cars. Water vapor is the only byproduct of a reaction in the fuel cell stack which generates electricity with oxygen from the surrounding air and hydrogen from a fuel tank. Auxiliary systems called balance of plant (BOP) serves to provide air and hydrogen to the stack in a correct ratio. The compressor is one of key components of this system because compression of the intake air brings an increase in efficiency and power density of FCEV. This paper presents the characteristics of a 10kW class centrifugal compressor with an oil-free bearing system. It consists of a shaft, two airfoil journal bearings and a pair of thrust bearings. They make it possible to obtain a compact high speed design and proper stability of the compressor without lubrication systems.
2016-04-05
Technical Paper
2016-01-1532
Kyoungtaek Kwak, Seungwoo Seo, Randi Potekin, Antoine Blanchard, Alexander Vakakis, Donald McFarland, Lawrence Bergman
In order to secure the safety of the passengers, the door should be kept closed during side impact crash and many car makers conduct a various research on this area. Typically, there are two major factors that affect the opening of door during side impact crash tests. One is a physical failure such as the damage of linkage of door locking system, which can be intuitively analyzed and resolved. The other is the inertia effect due to the instantaneous impact and deformation between a barrier and door outer panel. In case that the door opening is, however, resulted from the inertia effect, it is difficult to be intuitively resolved because it takes extremely short time less than 30ms for a whole phenomenon to come out. Also, because the randomly deformed outer panel due to the crash generates not only translational but also angular accelerations that more complicatedly affect dynamic behavior of door handle.
2016-04-05
Technical Paper
2016-01-1546
Dongpil Lee, Kyongsu Yi, Bongchoon Jang, Sehyun Chang, Byungrim Lee
This paper describes a reference steering feel tracking algorithm for Electric-Power-Steering (EPS) system. Development of the EPS system with intended steering feel has been time-consuming procedure, because the feedforward map-based method has been applied to the conventional EPS system. However, in this study, a three-dimensional reference steering feel surface, which is determined from current vehicle states, is proposed. In order to track the proposed reference steering feel surface, sliding mode approach is applied to second-order steering dynamics model considering a coulomb friction model. An adaptive technique is utilized for robustness against uncertainties. In order to validate the proposed EPS control algorithm, hardware-in-the-loop simulation (HILS) has been conducted with respect to various steering tests (Weave, Transition, Flick, and Return-ability). It is shown that the reference steering feel is realized well by the proposed EPS control algorithm.
2015-09-27
Journal Article
2015-01-2691
Ju Young Kim, Jeongkyu Kim, Young Min Kim, Wontae Jeong, Hojoon Cho
Abstract In the brake system, unevenly distributed disc-pad contact pressure not only leads to a falling-off in braking feeling due to uneven wear of brake pads, but also a main cause of system instability which leads to squeal noise. For this reason there have been several attempts to measure contact pressure distribution. However, only static pressure distribution has been measured in order to estimate the actual pressure distribution. In this study a new test method is designed to quantitatively measure dynamic contact pressure distribution between disc and pad in vehicle testing. The characteristics of dynamic contact pressure distribution are analyzed for various driving conditions and pad shape. Based on those results, CAE model was updated and found to be better in detecting propensity of brake squeal.
2015-09-01
Technical Paper
2015-01-1886
Joonsuk Kim, Kwang Min Chun, Soonho Song, Hong-Kil Baek, Seung Woo Lee
For gasoline engine, thermal efficiency can be improved by using lean burn. However, combustion instability occurs when gasoline engine is operated on lean condition. Hydrogen has features that can be used for improving combustion stability of gasoline engine. In this paper, an experimental study of hydrogen effect on lean limit was carried out using a four-cylinder 2.0L turbo gasoline direct injection engine. The engine torque was fixed at 110Nm on 1600RPM, 2000RPM and 2400RPM. The results showed that lean limit was extended and brake thermal efficiency was improved by hydrogen addition. Especially, at lower engine speed, the large improvement of lean limit was achieved. However, improvement of brake thermal efficiency was achieved at high speed. HC and CO2 emissions were decreased and NO emissions increased with hydrogen addition. CO emissions were slightly reduced with hydrogen addition.
2015-06-15
Technical Paper
2015-01-2297
Insoo Jung, Jaemin Jin, Kwangmin Won, Seungwook Yang, Kyoungdoug Min, Hoimyung Choi
Abstract The combustion noise of a diesel engine can be deteriorated by combustion characteristics such as the maximum rate of heat release and the start of combustion. These combustion characteristics in turn are influenced by the factors such as the engine NVH durability, driving conditions, environmental factors and fuel properties. Therefore, we need to develop the robust combustion noise that is insensitive to these factors. To achieve this aim, methods for predicting combustion characteristics has been developed by analyzing the vibration signal measured from the engine cylinder block. The closed-loop control of injection parameters through combustion characteristics prediction has been performed to produce the desired engine combustion performance. We constructed an ECU logic for the closed-loop control and verified the design in a diesel passenger car. We also evaluated the effect of combustion noise and fuel consumption by applying the closed-loop control.
2015-06-15
Journal Article
2015-01-2216
Dong Chul Park, Eun Soo Jo, Seokgwan Hong, Michael Csakan
Abstract An important trend among vehicle NVH engineers is the production of attractive engine acceleration sound quality for the enhancement of a vehicle's image and performance. In addition, customers have increasing interest and enjoyment in customizing their cars to reflect their personal taste and preferences. The PESS (Personalized Engine Sound System) has been developed for making a unique and individually customizable vehicle concept. The system allows the customers an opportunity to create a variety of engine sounds in a single vehicle using active sound design technology. In this system, three different engine sound concepts are pre-defined, Dynamic, Sporty, and Extreme. Each of the engine sounds can then be adjusted with parameters that determine the timbre, such as main order, rumble, and high order. In addition, the pedal position during acceleration has also been used as a parameter to further personalize the experience.
2015-06-15
Technical Paper
2015-01-2248
Florian Pignol, Emiel Tijs, Daniel Fernandez Comesana, Daewoon Kim
Abstract In order to apply an effective noise reduction treatment determining the contribution of different engine components to the total sound perceived inside the cabin is important. Although accelerometer or laser based vibration tests are usually performed, the sound contributions are not always captured accurately with such approaches. Microphone based methods are strongly influenced by the many reflections and other sound sources inside the engine bay. Recently, it has been shown that engine radiation can be effectively measured using microphones combined with particle velocity sensors while the engine remains mounted in the car [6]. Similar results were obtained as with a dismounted engine in an anechoic room. This paper focusses on the measurement of the transfer path from the engine to the vehicle interior in order to calculate the sound pressure contribution of individual engine sections at the listener's position.
2015-04-14
Technical Paper
2015-01-1312
MyoungKwon Je
Abstract The power sliding door system(PSD) is being equipped in the MPV(Multi-Purpose Vehicle/minivans) vehicle for convenience in the door operation. This study will focus on package space optimization for interior design and overall vehicle packaging for the vehicles equipped with PSD. To optimize the package, investigation for PSD's structure need to be done and the examples of other vehicle maker will be investigated and compared. The study that considers performance and package requirements resulted in a unique PSD design. And finally, this study will show the result vehicle in which the optimized mechanism is applied.
2015-04-14
Technical Paper
2015-01-0354
Ji Wan Kim, Tae Hee Lee
Abstract This study has been conducted to analyze microbial diversity and its community by using a method of NGS(Next generation sequencing) technique that is not rely on cultivation for microbial community in an core evaporator causing odor of car air conditioner. The NGS without any cultivation method of cultivation, has been developed recently and widely. This method is able to research a microorganism that has not been cultivated. Differently with others, it can get a result that is closer to fact, also can acquire more base sequence with larger volume in relatively shorter time. According to bacteria population analysis of 23 samples, It can be known limited number of bacteria can inhabit in Evaporator core, due to small exposure between bacteria and evaporate, as well as its environmental characteristics. With the population analysis, only certain group of it is forming biofilm in proportion.
2015-04-14
Technical Paper
2015-01-1188
Seongjun Yun, SungJin Park, Daekwang Kim, Junyong Lee, Sejun Kim, Kwang-yeon Kim
Abstract The fuel economy of a vehicle can be improved by recuperating the kinetic energy when the vehicle is decelerated. However, if there is no electrical traction component, the recuperated energy can be used only by the other electrical systems of the vehicle. Thus, the fuel economy improvement can be maximized by balancing the recuperated energy and the consumed energy. Also, suitable alternator and battery management is required to maximize the fuel economy. This paper describes a design optimization process of the alternator and battery system equipped with recuperation control algorithms for a mid-sized sedan based on the fuel economy and system cost. A vehicle model using AVL Cruise is developed for cycle simulations and validated with experimental data. The validated model is used for the parametric study and design optimization of the alternator and battery systems with single and dual energy storage.
2015-04-14
Technical Paper
2015-01-0685
Jeong Uk Ahn, Sung Moon Choi
Abstract Most bucket type valvetrain engines use DLC coated tappet for low friction and fuel efficiency. However the requirements on coating robustness have been increased as the tribological environments have become more severe by use of low viscosity oil or higher engine output. In order to obtain higher coating efficiency and improved wear resistance, 5∼9 at.% Si doped DLC (Si-DLC) coated tappet has been developed using PACVD process. Thermal stability and wear resistance of Si-DLC were improved impressively than those of DLC, although mechanical properties such as hardness and adhesion were degradated. It seems that Si suppresses a graphitization of DLC and thin SixOy film on coating surface acts as a barrier to oxidation or flash heat.
2015-04-14
Journal Article
2015-01-1566
Youngil Koh, Kyongsu Yi, Kilsoo Kim
Abstract This paper presents a tire slip-angle based speed control race driver model. In developing a chassis control system for enhancement of high-speed driving performance, analysis of the vehicle-driver interaction at limit handling is one of the main research issues. Thus, a driver model which represents driving characteristics in a racing situation is required to develop a chassis control system. Since a race driver drives a vehicle as fast as possible on a given racing line without losing control, the proposed driver model is developed to ensure a lateral stability. In racing situation, one of the reasons which cause the lateral instabilities is an excessive corner-entry speed. The lateral instability in that moment is hard to handle with only a steering control. To guarantee the lateral stability of the vehicle while maximizing a cornering speed, a desired speed is determined to retain a tire slip-angle that maximizes lateral tire forces without front tire saturation.
2015-04-14
Journal Article
2015-01-1309
Hyunggyung Kim
Abstract This Study describes about the development of new concept' rear wheel guards for the reduction of Road Noise in the passenger vehicles. The new wheel guards are proposed by various frequency chamber concept and different textile layers concept. Two wheel guards were verified by small cabin resonance and vehicle tests. Through new developing process without vehicle test, Result of road noise will be expected if this concepts and materials of wheel guard are applied into automotive vehicle. As this concept consider tire radiation noise frequency and multilayers sound control multilayers, 2 concepts reduced road noise from 0.5 to 1.0dB. The proposed method of part reverberant absorption is similar to results of vehicle tests by part absorption index. Furthermore, optimization of frequency band in wheel guards will reduce more 0.5 dB noises.
2015-03-10
Technical Paper
2015-01-0010
Sungwon Lee, Seung Jeon, Jae Woon Lee, Cha-Sub Lim
Abstract In this study, several design factors are considered to predict door deformation. Door deformation is mainly influenced by air flow around A-pillar and door static stiffness. Therefore design factors can be divided into two categories. First, design elements determined by the appearance of a car affect to the air flow around A-pillar. Second, door static stiffness is determined by engineering design parameters. Kriging method is used to predict door deformation by means of the design factors. Door deformation can be successfully predicted with this method.
2015-03-10
Technical Paper
2015-01-0018
Dongwon Yeon
Abstract There are some problems “windows fog up a lot” for ventilation system. We have Test Development Procedure to prevent the fog problems. But, Many fog problems occurred in the cars that we made. So in this paper, new ventilation system is needed and developed. The Smart Ventilation System automatically controls indoor air quality even though the blower motor is off. There are two sensors that is used for AutoDefogSensor system and CO2 CONTROL system.. The sensor is on when blower motor and heater control is off. We use these signals and make new ventilation logics. We evaluate this system in chamber & '13 winter test in USA.
2015-03-10
Technical Paper
2015-01-0019
Heeyun Lee, Suk Won Cha, Hyunsup Kim, Seok-Joon Kim
Abstract This paper is concerned with the energy management strategy of hybrid electric vehicle using stochastic dynamic programming. The aim is the control strategy of the power distribution for hybrid electric vehicle powertrains to minimize fuel consumption while maintaining drivability. The fuel economy of hybrid electric vehicle is strongly influenced by power management control strategy. Rule-based control strategy is popular strategy thanks to its effectiveness in real-time implementation, but rule should be designed and efficiency of entire drive trains is not optimized. Dynamic programming, one of optimization-based control strategy presents outstanding performance, but cannot be used as real-time control strategy directly, since its non-causal property and drawback that global optimal solution can only be obtained for specific driving cycle.
2015-03-10
Technical Paper
2015-01-0025
Jaeyong Park, Joonhong Park, JinHee Lee, Yong-Sub Yi, TeaWon Park
Abstract In the view point of driving safety, the crosswind sensitivity of a vehicle becomes more important, as the driving speed in highway gets higher in these days. The sensitivity of a vehicle to crosswind depends on many factors, including the design of the suspension and aerodynamics of the body, etc. However, the knowledge about this phenomenon has still to be improved, in order to develop vehicle with optimum characteristics for crosswind stability. In this research, the physics behind the sensitivity of a vehicle is discussed in detail through various kinds of virtual test using computer aided engineering (CAE) simulation scheme. In the first, a reliable simulation model for vehicle, driver, wind generator and interactions among them is built. This simulation model is verified by comparison with test results of real vehicle. Then, the sensitivity analysis is carried out to find out the most influential design parameters.
2015-03-10
Technical Paper
2015-01-0024
Jaehaeng Yoo
Abstract For the robust passenger NCAP(New Car Assessment Program) 5star and the stable neck injury performance, a new concept of passenger airbag has been required. Especially, the deployment stability and the vent hole control technology of the passenger airbag can be improved. According to these requirements, the deployment stability technique has been studied and the ‘Active Vent’ technology has been developed. As a result, these technologies have led to achieve the robust NCAP rating and are applied to the production vehicles.
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