Viewing 1 to 12 of 12
Technical Paper
Seungha Lee, Youngbok Lee, Kyoungchan Han, Kyoung Min Lee, Jun Yu, Junyong Lee, Kyoungdoug Min
Nowadays, diesel engine-out exhaust NOx emission level prediction is one of the major challenges for not only that complies with the stricter emission legislation but also for a controlling purpose of the after-treatment system. Most of the NOx prediction researches are based on Zeldovich thermal mechanism, which is reasonable for physical point of view and simplicity. Nevertheless, there are some predictable range limitations as low temperature with high EGR rate operating conditions or high temperature with low EGR rates. In the present paper, 4 additional considerations: pilot burned gas mixing before the main injection; major NO formation area; concentration correction; NOx decomposition, were applied with the previous developed real-time NO estimation model based on in-cylinder pressure and data available from ECU by authors. The model improvement was verified on a 1.6 liter EURO5 diesel engine in both steady and transient operation.
Technical Paper
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.
Technical Paper
Sangchul Lee, SeongMin Park, Changsun Hwang
Low pressure EGR system (LP EGR system) enables to expand operating area of EGR than previous high pressure lonely EGR system. As a result, fuel consumption and emissions could be improved. For meeting EU 5 emissions regulation, we applied exhaust throttle LP EGR system. With these system, our EU5 vehicles got merit than competitor's. But because exhaust throttle LP EGR valve has installed adjacent after-treatment system, material of LP EGR valve itself had no choice but stainless steel (SUS) for enduring against thermal stress. Consequently, it occurred cost increasing. To achieve cost rationalization for EU 6 vehicles, we have developed to apply intake throttle LP EGR system instead of exhaust throttle LP EGR system. In case of applying intake throttle LP EGR system, EGR valve could be installed in front of turbo charger compressor. Under this installation circumstance, we can have wider range of material selection (e.g. Al).
Technical Paper
Ki-Hwa Lee, Chung-Guen Nam, Hyung-Shin KIm, Dong-Kyu Yoo, Koo-Tae Kang
A comprehensive investigation was carried out in order to develop the idle sound quality for diesel V6 engine when the engine development process is applied to power-train system, which included new 8-speed automatic transmission for breaking down the noise contribution between the mechanical excitation and the combustion excitation. First of all, the improvement of dynamic characteristic can be achieved during the early stages of the engine development process using experimental modal analysis (EMA) & the robust design of each engine functional system. In addition, the engine structural attenuation (SA) is enhanced such that the radiated combustion noise of the engine can be maintained at a target level even with an increased combustion excitation. It was found that the engine system has better parts and worse parts in frequency range throughout the SA analysis. It is important that weak points in the system should be optimized.
Technical Paper
Dongkon Lee, Franck Perot, Kang-Duck Ih, David Freed
Nowadays vehicle quality is rated for noise and vibration and the interior sound levels have become a major target of automotive companies. Strides have been made in reducing power train, tire and external wind noise over the years. However, HVAC and blower fan flow-induced noise reaches the interior cabin without any sound isolation and can strongly impact customer comfort. In the early stage of vehicle design, it is experimentally difficult to get an estimate of the flow pattern and sound levels. The goal of this study is to develop and validate a numerical noise prediction tool for complete HVAC systems noise, defined as the arrangement of sub-systems such as air intake duct, thermal mixing unit, blower, ducts and outlet vents. This tool can then be used during the development of vehicles to evaluate and optimize the aeroacoustics performances of the system without additional or belated experiments.
Technical Paper
Yong Woo Park, Hyo Seok Kim, Kwangjin Joo, Namil Jeon
The purpose of this paper is to identify and reduce the suspension rattle noise. First, the characteristics of the rattle noise are analyzed experimentally in the time and frequency domain. It was found that the rattle noise and vibration at shock absorber mounting point are strongly correlated. Second, the sensitivity analysis of design parameters is performed using a half car model in ADAMS. The result of the simulation model is verified by comparison with test. Finally, the influence of design parameters for the rattle noise is investigated. The study shows that the shock absorber mounting bushing is the most sensitive parameter to affect the suspension rattle noise. This paper shows how the suspension rattle noise can be improved.
Technical Paper
Sangjoon Kim, Joonyoung Park, Jeongho Hong, Myungwon Lee, Hyunsung Sim
Transient control for EV/HEV mode change takes an important role in the system of the parallel HEV, which consists of internal combustion engine (ICE), electric motor (EM), integrated starter & generator (ISG), battery, automatic transmission and clutch (that replaces the torque converter), not only ICE/EM control but also clutch engagement control are the key of it. To improve the mode change performance, this study proposes clutch slip control methods. Method 1. focuses on the open loop clutch pressure control so as to adjust target clutch transfer torque. The main idea of Method 2. is to control the clutch pressure in order to achieve the desired speed difference(Method 2-1) from each side of clutch when motor speed is faster than engine idle speed and keep target engine speed(Method 2-2) when motor speed is slower than engine idle speed. This paper defines control sequence which is scheduling the behavior of powertrain components as well.
Technical Paper
Do Hoi Kim, Kyung Ryol Yun, Kal Hyuk Je
At present, the assembling order of COWL is decided according to the design of the Vehicle’s A pillar outer. Therefore when the factory layout changes, extensive costs are needed according to the changes of the A pillar outer design. Thus, this study was carried out to develop a new COWL structure that is able to determine the layout of the factory without changing the design of the A pillar outer. In addition, by adjusting the DFSS tool to COWL, the direction of the material and thickness of COWL was studied to optimize the dynamic stiffness of the body structure and pedestrian protection performance. Based on this study, the optimization of the OPEN COWL is presented.
Technical Paper
Seungjae Lee, Junwan Tak, Sunsuk Ok, Jangdon Choi, Sangki Kim, Taeyeon Lee, Ealgoo Kim, Hakbong Kim, Jaehong Park
This paper describes the ground system model and algorithm for a ground level simulation tool. First, the modeling of an automotive ground system will be discussed and the algorithm for a simulation tool will be explained. We divided the model into a ground tree and a ground body. The ground tree model consists of resistance formed by the wires that connect the load to ground point with various structures and the ground body model consists of resistance between ground points in the car body. The wires with large current, such as engine ground cable, was modeled in detail by dividing the resistance into wire, bolt, and clamping resistance, in order to simulate the effect of increased contact resistance after durability test. The algorithm of the ground level simulation tool was designed to adjust the currents of the alternator, battery, and ground points in order to evaluate the various driving and load conditions.
Technical Paper
Gi-Ho Lee, Jong-Hoon Lim, Gi-Tae Kim
Ride quality of heavy duty truck becomes important item, due to long distance transfer and long time driving This study describes how to determine and evaluate design parameters related to cab suspension system through time and frequency domain analysis The spring and damper-stiffness of the cab suspension system were optimized by two objective functions, which consist of cab pitching acceleration peak level and vibrational absorbed power Cab pitching is the main item which should be studied for ride quality In an attempt at optimizing, we made use of “Taguchi Method”,which was applied to experiments and simulation. We made truck cab model by use of DADS, which is dynamic analysis software,in order to find out the cab motions The results of simulation and test of a heavy duty truck gave us the optimum design parameters, which were verified and confirmed by real vehicle test
Technical Paper
Hae-Woo Park, Chang-Seok Han, Chul-Soo Kim, Bong-Ho Lee, Young-Woo Kim, Paul R Gifford
Abstract The development of a high-performance battery and safe and reliable charging methods are two important factors for commercialization of the Electric Vehicles(EV) Hyundai and Ovonic together spent many years in the research on optimum charging method for Ni-MH battery This paper presents in detail the results of intensive experimental analysis, performed by Hyundai in collaboration with Ovonic An on-board Ni-MH battery charger and its controller which are designed to use as a standard home electricity supply are described In addition, a 3 step constant current recharger with the temperature and the battery aging compensator is proposed This has a multi-loop algorithm function to detect its 80% and fully charged state, and carry out equalization charging control The algorithm is focused on safety, reliability, efficiency, charging speed and thermal management (maintaining uniform temperatures within a battery pack) It is also designed to minimize the necessity for user input.
Technical Paper
Dong Hoon Park, Tae Seok Seo, Do Gi Lim, Hee Bock Cho
This paper introduces mathematical equations for power loss calculations of major automatic transmission components. It also presents a theoretical investigation on contributions of each component's power loss to transmission total power losses. A computer program for automatic transmission efficiency calculation has been developed based on mathematical equations. Efficiency calculations for the Hyundai A4BF1 electronic 4 speed automatic transmission has been executed in order to validate the program. The calculated efficiency under various input and operating conditions - such as different input torque & RPM, transmission gear state, ATF temperature, torque converter clutch on/off - showed quite good agreement with the test results.
Viewing 1 to 12 of 12


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