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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Automotive Engineers
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Journal DOI :
The Korean Society of Automotive Engineers
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Volume & Issues
Volume 23, Issue 6 - Nov 2015
Volume 23, Issue 5 - Sep 2015
Volume 23, Issue 4 - Jul 2015
Volume 23, Issue 3 - May 2015
Volume 23, Issue 2 - Mar 2015
Volume 23, Issue 1 - Jan 2015
Selecting the target year
Application and Analysis of 2D FRI (Finite Rate of Innovation) Super-resolution Technique in Vision Navigation
Yoo, Kyungwoo ; Kong, Seung-Hyun ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 1~10
DOI : 10.7467/KSAE.2015.23.1.001
In urban area, since multipath and signal attenuations frequently occur due to street trees, street lights and buildings, it is difficult to obtain accurate navigation solution using GPS. As these problems also impact negatively on the INS/GPS coupled system, implementing advanced transportation systems such as autonomous navigation system and Intelligent Transportation System (ITS) become quite hard. For this reason, to alleviate deterioration of navigation system performance in urban area, direction information extraction algorithm using vision system is proposed in this paper. 2D Finite Rate of Innovation (FRI) technique is applied to extract lane edges. The proposed technique is simulated using road images and feasibility of proposed technique is analyzed through the simulation results.
Driving Performance Analysis of a Rear In-wheel Motor Vehicle with Simultaneous Control of Driving Torque and Semi-active Suspension System
Shin, Sulgi ; Choi, Gyoojae ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 11~17
DOI : 10.7467/KSAE.2015.23.1.011
Recently, the in-wheel motor vehicle is rapidly developed to solve energy exhaustion and environmental problems. Especially, it has the advantage of independently driving the torque control of each wheel in the vehicle. However, due to the weight increase of wheel, the comfort of vehicle riding and performance of road holding become worse. In this paper, to compensate the poor performance, a simultaneous control of the driving torque and semi-active suspension system is investigated. A vehicle model is generated using CarSim Software and validated by field tests. Co-simulation of CarSim and MATLAB/Simulink with control logics is carried out, and it is found that simultaneous control of the driving torque and semi-active suspension system can improve driving stability and durability of the in-wheel motor system.
Experimental Study on the Performance Characteristics of a CO
Air-conditioning System for Vehicles
Lee, Daewoong ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 18~24
DOI : 10.7467/KSAE.2015.23.1.018
In this study, a
air-conditioning system was investigated with different types of electrically driven compressors, parallel flow type gas cooler, four-pass type evaporator, internal heat exchanger integrated with accumulator, and electric expansion valve. The experimental study was conducted under various operating conditions (ie., different rotational compressor speeds, air inlet temperatures and air velocity coming into heat exchangers). The experimental results showed the cooling capacity was 3.5kW at
ambient temperature when the vehicle was idle (ie., the worst condition for cooling off the gas cooler). In terms of performance effect of the compressor, the e-RP model had a slightly better cooling capacity and coefficient of performance than the e-GR model under the same test conditions. An experimental equation for optimum cooling-performance control was also suggested based on the results. A high-pressure control algorithm for the super critical cycle was determined to achieve both maximum cooling performance and efficient energy consumption. The results from the experimental equation coincided with those of previous experimental studies.
Prediction of Iron Loss Resistance by Using HILS System
Jeong, Kiyun ; Kang, Raecheong ; Lee, Hyeongcheol ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 25~33
DOI : 10.7467/KSAE.2015.23.1.025
This paper presents the d-q axis equivalent circuit model of an interior permanent magnet (IPM) which includes the iron loss resistance. The model is implemented to be able to run in real-time on the FPGA-based HIL simulator. Power electronic devices are removed from the motor control unit (MCU) and a separated controller is interfaced with the real-time simulated motor drive through a set of proper inputs and outputs. The inputs signals of the HIL simulation are the gate driver signals generated from the controller, and the outputs are the winding currents and resolver signals. This paper especially presents iron loss prediction which is introduced by means of comparing the torque calculated from d-q axis currents and the desired torque; and minimizing the torque difference. This prediction method has stable prediction algorithm to reduce torque difference at specific speed and load. Simulation results demonstrate the feasibility and effectiveness of the proposed methods.
Optimization of Automotive PEMFC Bipolar Plates considering Heat Transfer and Thermal Loads
Kim, Young-Sung ; Kim, Cheol ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 34~40
DOI : 10.7467/KSAE.2015.23.1.034
A stack in the proton exchange membrane fuel cell (PEMFC) consists of bipolar plates, a membrane electrode assembly, a gas diffusion layer, a collector and end plates. High current density is usually obtainable partially from uniform temperature distribution in the fuel cell. A size optimization method considering the thermal expansion effect of stacked plates was developed on the basis of finite element analyses. The thermal stresses in end, bipolar, and cooling plates were calculated based on temperature distribution obtained from thermal analyses. Finally, the optimization method was applied and optimum thicknesses of the three plates were calculated considering both fastening bolt tension and thermal expansion of each unit cell (72 cells, 5kW). The optimum design considering both thermal and mechanical loads increases the thickness of an end plate by 0.64-0.83% the case considering only mechanical load. The effect can be enlarged if the number of stack increases as in an automotive application to 200-300 stacks.
The Study of Roll-forming Technology for UHSS Hydroformed Parts
Park, Sungpill ; Kwon, Yongjai ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 41~48
DOI : 10.7467/KSAE.2015.23.1.041
In the automotive industry, it is required to reduce weight of the car and improve fuel efficiency. Competitive pricing is also a very important issue. That's why application of welded steel tube is increasing in order to produce a vehicle with a competitive price. Also, hydroforming technology is asking more and more for thinner tubing to realize to a lighter vehicle design. Steel tube is produced through a multi-stage process called roll forming. In that case, bucking and work hardening should be considered key forming technology is to prevent buckling and minimize work hardening during steel tubing for hydroforming To prevent buckling, it is required to optimize forming process in order to minimize stretching in edge sections and hold tightly cross-section during welding. And to minimize work hardening, it is needed to know the proper process to avoid reforming.
Development of Air Cutoff Valve for Improving Durability of Fuel Cell
Park, Jeonghee ; Lee, Changha ; Kwon, Hyuckryul ; Kim, Chimyung ; Choi, Kyusung ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 49~55
DOI : 10.7467/KSAE.2015.23.1.049
In this study, among in various scenarios of the duration degradation of the fuel cell, countermeasures for the cathode carbon carrier oxidation and the deactivation of catalyst by hydrogen / air interface formation have been studied. so the system was applied to the air cutoff valve. In terms of the component, the cold start performance, electrical stability, the airtight performance were mainly designed and their performance was confirmed. And in terms of the system, the air electrode flow is blocked off, so the oxygen concentration drops when system is powered off, As a result, By reducing unit cell voltage which affect the durability of the fuel cell reached up to 0.8V, the improved durability of the fuel cell was confirmed.
Model-based Gain Scheduling Strategy for Air-to-fuel Ratio Control Algorithm of Passenger Car Diesel Engines
Park, Inseok ; Hong, Seungwoo ; Sunwoo, Myoungho ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 56~64
DOI : 10.7467/KSAE.2015.23.1.056
This study presents a model-based gain scheduling strategy for PI-based EGR controllers. The air-to-fuel ratio is used as an indirect measurement of the EGR rate. In order to cope with the nonlinearity and parameter varying characteristics of the EGR system, we proposed a static gain model of the EGR system using a new scheduling parameter. With the 810 steady-state measurements, the static gain model achieved 0.94 of R-squared value. Based on the static gain of the EGR system, the PI gains were robustly designed using quantitative feedback theory. Consequently, the gains of the PI controller are scheduled according to the static gain parameter of the EGR path in runtime. The proposed model-based gain scheduling strategy was validated through various operating conditions of engine experiments such as setpoint step responses and disturbance rejections.
The Research for Higher Ride Quality with OPAX and OTPA
Shin, Kwangsoo ; Choi, Sangill ; Kim, Jongsik ; Lee, Sangkwon ; Im, Sebin ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 65~73
DOI : 10.7467/KSAE.2015.23.1.065
The ride quality has become a key component of not only design but car selling as the technology developed and the requirement of passengers grew up. Thus car industry invests lots of time and cost for the higher ride quality. The evaluation of the ride quality mainly is expressed by subjective element that drivers felt. In this paper, instead of the original transfer path analysis method, relatively new methods such as OPAX(Operational path analysis with eXogeneous inputs) and OTPA(operational transfer path analysis) are used for analyzing the main hindrance element of ride quality. With those new method, contribution rate of all paths that the vibration propagate along analyzed after driving test on the roads having different characteristic. The comprehensive hindrance elements of ride quality are deduced from the contribution rate and the improve experiment by changing one of hindrance elements for higher ride quality.
A Numerical Study of the Effect of Small Passenger Car's Grille Shape on the Aerodynamic Performance
Kim, Jaemin ; Cho, Hyeongkyu ; Kim, Taekgi ; Kim, Moonsang ; Kim, Yongsuk ; Kim, Yongnyun ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 74~87
DOI : 10.7467/KSAE.2015.23.1.074
A numerical parametric study has been accomplished to figure out the effect of grille shape built in a small passenger car on the aerodynamic performance such as drag and mass flow rate through CRFM(Condenser Radiator Fan Module). Three grille opening parameters and three grille mesh parameters are selected and adopted to a simple shape passenger car model. This research will provide a design guideline for grille opening geometry and mesh shape in the grille. FLUENT, which is very well known commercial code, hires k-
turbulence model at the driving speed of 110km/h with moving wall boundary condition. A porous media condition is prepared to estimate the pressure drop amount through CRFM parts.
Study on Evaluation Method of Flow Characteristics in Steady Flow Bench(1) - Raising Issue
Park, Chanjun ; Ohm, Inyong ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 88~96
DOI : 10.7467/KSAE.2015.23.1.088
This paper is the first investigation on the evaluation methods of flow characteristics in the steady bench. For this purpose, several assumptions used in the steady flow evaluation are examined, comparing the measured and/or processed results by the conventional impulse swirl meter with the ones by the real velocity through a particle image velocimetry. The results show that the most questionable assumption is the solid rotation of swirl. With regard to this assumption, the flow characteristics by the conventional methods are distorted seriously by both of the eccentricity of the swirl center and non-uniform velocity profile along the cylinder radial direction. In addition, the cylinder axial velocity distribution also has the great effect on the flow characteristics.
An Experimental Analysis for System Optimization to Reduce Smoke at WOT with Low Volatile Fuel on Turbo GDI Engine
Kim, Dowan ; Lee, Sunghwan ; Lim, Jongsuk ; Lee, Seangwock ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 97~104
DOI : 10.7467/KSAE.2015.23.1.097
This study is a part of the high pressure injection system development on the Turbo GDI engine in order to reduce smoke emission in case of using the low volatile(high DI) fuel which is used as normal gasoline fuel in the US market. Firstly, theoretical approach was done regarding gasoline fuel property, performance, definition of particle matters and its creation as well as problems of the high DI fuel. In this experimental study, 2L Turbo GDI engine was selected and optimized system parameter was inspected by changing fuel, fuel injection mode (single/multiple), fuel pressure, distance between injector tip and combustion chamber, start of injection, intake valve timing in engine dyno at all engine speed range with full load. In case of normal gasoline fuel, opacity was contained within 2% in all conditions. On the other hands, in case of low volatile fuel (high DI fuel), it was confirmed that the opacity was rapidly increased above 5,000 rpm at 14.5 ~ 20 MPa of fuel pressure and there were almost no differences on the opacity(smoke) between 17 MPa and 20 MPa fuel pressure. According to the SOI retard, smoke decrease tendency was observed but intake valve close timing change has almost no impact on the smoke level in this area. Consequently, smoke decrease was observed and 16% at 6000rpm respectively with injector washer ring installed. By removing injector washer to make injector tip closer to the combustion chamber, smoke decrease was observed by 46% at 5,500 rpm, 42% at 6,000 rpm. It is assumed that the fuel injection interaction with cylinder head, piston head, intake and exhaust valve is reduced so that impingement is reduced in local area.
Design of Bumper Backbeam Center Reinforcement Bracket for IIHS Full Overlap Bumper Test
Kang, Sungjong ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 105~111
DOI : 10.7467/KSAE.2015.23.1.105
Since 2007, Insurance Institute of Highway Safety(IIHS) has conducted the new bumper test using bumper barrier to estimate the repair cost of impacted vehicle. In this study, for the front body FE model of a medium size passenger car analyzes were carried out to optimize the shape of backbeam center reinforcement bracket. First, overlap effect was examined with changing the overlap magnitude and spot welds were added along the backbeam center line for reducing the section shear deformation. Next, for an overlap model design parameter study was performed for the bracket. Thickness effect was examined and an inner reinforcement was added to the bracket. Also, the lower part of bracket was deleted and additionally the bracket length was extended. The results were discussed in terms of backbeam backward deflection, barrier backstop intrusion and weight. Compared with the current design, the final model showed 44.1% bracket weight reduction with 30.0% decrease of backbeam deflection.
Analysis of Powertrain Characteristics for Output Split Type Plug-in Hybrid Electric Vehicle
Kim, Jeongmin ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 112~121
DOI : 10.7467/KSAE.2015.23.1.112
In this paper, powertrain of output split type plug-in hybrid electric vehicle is analyzed for the operation range of speed, torque, and power. First, it is assumed that the efficiency of motor is 100%. And, the speed and torque equations are derived based on the lever analogy. With the above equations, the simulations are performed for the powertrain of output split type plug-in hybrid electric vehicle. From the simulation results, it is found that the output torques of EV1 and series modes are larger than the EV2 and power split modes' ones. It means the EV1 and series modes can be used for the rapid acceleration. But the EV1 and series modes can be used only the velocity of under the 120 km/h. It is because the motor reaches its maximum speed when the velocity is over the 120 km/h for the EV1 and series modes. When the engine is turned on, the engine power is transmitted through the two motors. But, the power split mode shows the power split of engine at the output shaft, and it has the point of zero motor power. Thus, the transmission efficiency of the power split mode can be higher than the series mode's one, it the motor efficiency is considered.
A Study of Temperature Predictions for Manual Transmission Clutch System via Anti-fade and Hill Start Virtual Test
Park, Ki-Jong ; Kim, Dong-Won ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 122~129
DOI : 10.7467/KSAE.2015.23.1.122
Excessive overheating to a manual transmission clutch system under operating conditions can be considered the main reason of its performance degradation. The clutch system has to be ensured with its service life by showing that it passes the extreme tests called anti-fade test and hill start test in a certain design step. In general, design feedbacks from these kinds of the experiments are adapted to the system to enhance its performance. However, it usually takes much time and costs a lot due to the repetition of the tests. In this research, a process to calculate temperature of the clutch system was developed to determine whether the design can be passed the anti-fade test and hill start test in the design phase. The process incorporates many CAE techniques such as heat transfer analysis using 1D dynamic simulation method, system dynamics, CFD and parametric optimization. CFD is utilized to analyze 3-dimensional heat transfer of the clutch system and fluid dynamics of air in the clutch housing. The process was applied for the clutch systems in several vehicle models. The results was compared with those of the experiment. The applicability of the developed process was verified by comparing the predicted results with experimental results.
Characteristics of Real-road Driving NOx Emissions from Korean Light-duty Vehicles regarding Driving Routes
Oak, Seonil ; Eom, Myoungdo ; Lee, Jongtae ; Park, Junhong ; Kim, Jichul ; Chon, Mun Soo ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 130~138
DOI : 10.7467/KSAE.2015.23.1.130
Despite of recently strengthened vehicle emission regulations, NOx emissions are not decreased in urban areas because of discrepancies between certification emission test modes and real driving conditions. Thus, researches on RDE-LDV (Real-driving Emission-Light-duty Vehicle) have been conducted actively using PEMS (Portable Emissions Measurement Systems). In the present study, NOx emissions were measured for 5 Korean light duty vehicles for real driving conditions including city, combined, highway, and up-downhill test route. Emission characteristics were analyzed for averaged NOx emissions per unit driving distance of each driving test routes. Furthermore, MAW (Moving Average Window) method based on
emissions from WLTC, which will be supported for EU regulations, was utilized. It was revealed that DRs (deviation ratios) for diesel vehicles (i.e., 5.1 ~ 8.4) were greater than gasoline vehicles (less than 0.15). Especially DR of diesel vehicle for up-downhill test route was 8.4, which indicates severe NOx emissions.
Study on Evaluation Method of Flow Characteristics in Steady Flow Bench(2) - Comparison of ISM and PIV Measurement
Park, Chanjun ; Ohm, Inyong ;
Transactions of the Korean Society of Automotive Engineers, volume 23, issue 1, 2015, Pages 139~147
DOI : 10.7467/KSAE.2015.23.1.139
This paper is the second investigation on the evaluation methods of flow characteristics in a steady flow bench. In the previous work, several assumptions used in the steady flow bench were examined and it was concluded that the assumption of the solid rotation might cause serious problems. In this study, intake valve angle is selected as a main parameter for the assessment because the main flow direction to cylinder governed by this angle has the strongest influence on the in-cylinder flow pattern. For this purpose, four heads, which have the different angle, are prepared and the flow characteristics are estimated both by the conventional impulse swirl meter and a particle image velocimetry at 1.75 times bore position apart from the cylinder head, which is widely used plane in the steady flow measurement. The results show that both of the eccentricity and the velocity profile distort the flow characteristics when using the ISM at 1.75 plane, however, the effects of two factors act in the opposite direction. In addition, the profile's influence is much greater than that of the eccentricity.