• Proceedings of the KSR Conference
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• 2008.11b
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• pp.584-589
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• 2008

A bi-modal tram has been developing to consist of articulated-two cars propelled by CNG hybrid (series type) in Korea since 2003. All wheels are driven by electrical motors independently, which can eliminate differential gears to reduce turning radius and make low floor to provide the old and the handicapped with easy access. In the bi-modal tram, therefore, reduction gear unit is key technology to make low floor and drive wheels independently. This study was aimed at performance evaluations of the reduction gear unit for the bi-modal tram. Oil leakage, oil temperature, vibration, acoustic noise in idle operations were measured for the reduction gear unit of the bimodal tram.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.4
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• pp.423-430
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• 2019

The convergence of the automotive industry and the ICT technology can be broadly divided into the commercial service sector and the Cooperative-ITS (C-ITS) service sector. The C-ITS service sector is using V2X communication technology as a field that aims to provide safer transportation, more green and efficient transportation, and more predictable and productive mobility. The recent convergence of self-driving cars and connected cars requires high data rates, low transmission delays, and low transmission error rates. Interest in comparison of performance between WAVE and C-V2X (LTE-V2X, 5G-V2X) has been amplified and application services by communication technology are being studied. In this paper, we design the application performance evaluation method of Hybrid V2X communication system and confirm that the decrease of packet error rate (PER) performance is caused by the increase of communication distance, not the vehicle speed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2252-2260
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• 2015

In this paper, we propose a vehicular cooperative navigation system using GNSS, vision sensor and radar sensor that are frequently used in mass-produced cars. The proposed cooperative vehicular navigation system is a variant of the Hybrid-Sum Product Algorithm over Wireless Network (H-SPAWN), where we use vision and radar sensors instead of radio ranging(i.e.,UWB). The performance is compared and analyzed with respect to the sensors, especially the position estimation error decreased about fifty percent when using radar compared to vision and radio ranging. In conclusion, the proposed system with these popular sensors can improve position accuracy compared to conventional cooperative navigation system(i.e.,H-SPAWN) and decrease implementation costs.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.2
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• pp.152-160
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• 2011

The electromagnetic characteristics of FCEVs (fuel cell electric vehicles) are much different from the existing combustion engine cars as well as hybrid, plug-in-hybrid, and pure electric vehicles due to the high voltage/current generated by a fuel cell stack which uses a compressed hydrogen gas reacted with oxygen. To operate fuel cell stack efficiently, BOP (Balance of Plant) which is consisted of many motors in water pump, air blower, and hydrogen recycling pump as well as inverters for these motors is essential. Furthermore, there are also electric systems for entertainment, information, and vehicle control such as navigation, broadcasting, vehicle dynamic control systems, and so on. Since these systems are connected by high voltage or general cables, EMC (Electromagnetic compatibility) analysis for high voltage and general cable of FCEV is the most important element to prevent the possible electric functional safety errors. In this paper, electromagnetic fields by high voltage and general cables for FCEVs is studied. From numerical analysis results, total time harmonic electromagnetic field strength from high voltage and general cables have difference of 13~16 dB due to ground effect by impedance matching. The EMI results of FECV at 10 m distance shows difference of 41 dB at 30 MHz and 54 dB at 230 MHz compared with only general cable routing.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.256-261
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• 2011

In this paper, a design and an implementation of an Analog to Digital (A/D) converter are introduced for the conversion of monitored battery cell voltage in the cell voltage monitoring(CVM) system in battery management system(BMS), which is one of the key devices of ECO hybrid cars. The A/D converter in CVM system required a middle conversion speed and a high resolution, therefore, a successive approximate register(SAR) typed A/D converter with 10 bits resolution has been designed and implemented using Magna 0.6um 40V process. The measurement result which kept ${\pm}1$ LSB accuracy in the full scale range(FSR) of 5V, showed the usefulness of the SAR typed A/D converter in realizing a CVM system.

• Journal of Auto-vehicle Safety Association
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• v.9 no.1
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• pp.13-18
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• 2017

In recent years, NCAP regulations of many countries have induced automaker to improve the vehicle crashworthiness. But, the current NCAP regulations don't cover all types of traffic accidents. And rapid-increasing market share of compact cars and SUVs has brought for both consumer and automaker to pay more attention on crash compatibility. So, many countries have tried to develop the new crash test mode and update the present crash test mode. Especially, Euro NCAP has been developing a new impact protocol of the car-to-car frontal offset impact including the crash compatibility assessment. There are plans to introduce this new protocol in 2020, and it will be replaced the current Euro NCAP frontal offset impact. The test dummy in the front seats of this new test mode will be changed from 50% Hybrid-III male to 50% THOR male. This paper will address the vehicle responses, the occupant responses and the vehicle compatibility performance from a full vehicle crash test using the new car-to-car frontal offset test protocol of Euro NCAP.

• Transactions of Materials Processing
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• v.22 no.3
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• pp.133-142
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• 2013

Recently, electric vehicles and hybrid cars are being promoted as alternatives to reduce automobile emissions. Generally, thin sheet materials such as aluminum alloy AA300X and cold-rolled steel sheet such as JIS-G-3141 are used for the container for the lithium-ion secondary batteries. In this study, a multi-stage deep drawing process is used to produce a rectangular cup from thin stainless steel sheet material, SUS409L, with an initial blank thickness of 0.4mm for the battery container application. Numerical simulations of the first through the fifth stages for the multi-stage deep drawing with thin SUS409L sheet were conducted using LS-Dyna3D Implicit/Explicit. Special consideration was given to the deformation characteristics due to the normal anisotropy of the sheet material. The numerical simulations were conducted with both isotropic properties and the anisotropic properties of the initial blank material. An unexpected forming failure, barreling in the bottom region of the deep drawn rectangular cup, was observed. This failure mode can be avoided by additional ironing thickness control during the process.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.75-83
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• 2001

RIM(Reaction Injection Molding) is a widely used method to manufacture middle-large size outfit-part for a prototype car. The main advantage of RIM is the capability of manufacturing a small number of prototype parts with less cost and lead time than injection molding which is the most popular method to manufacture plastic parts. Generally, epoxy resin and RTV(Room Temperature Vulcanization) silicon are used as mold materials for RIM, and the selection of mold materials is usually depended upon the industrial environment of manufactures and it decides overall mold making process and part quality. This paper suggests a new mold making process by consolidating the advantages of epoxy resin and RTV silicon based RIM mold to enhance the parts quality while reducing the manufacturing cost and time and shows the competitiveness of the suggested process compared with conventional methods.

• Journal of Drive and Control
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• v.9 no.1
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• pp.1-9
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• 2012

Nowadays, various researches about eco-friendly vehicles such as hybrid electric vehicle, fuel cell vehicle and electric vehicle have been actively carried out. Since most of these green cars have electric motors, the regenerative energy technology can be used to improve the fuel economy and the energy efficiency of vehicles. The regenerative brake is an energy recovery mechanism which slows a vehicle by converting its kinetic energy into electric energy, which can be either used immediately or stored until needed. This technology plays a significant role in achieving the high energy usage. However, there are some technical problems for controlling the regenerative braking and the electro-hydraulic brake during switching at transient region. In this paper, the performance simulator for fuel-cell vehicle is developed and transient response characteristics of the regenerative braking system are analyzed in the various driving situations. And the hardware-in-the-loop simulation of electro-hydraulic brake is performed to validate the transient characteristics of the regenerative braking system for fuel-cell electric vehicle.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.98-105
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• 2014

As environmentally friendly energy takes center stage, interests for Electric Vehicles/Plug in Hybrid Electric Vehicles (EVs/PHEVs) are getting increase. With this trend, there is no doubt EVs will take large portion to penetrations of total cars. Therefore, accurate EV modeling is required. Battery is one of the main components with the power system view of aspect. Hence, in this paper, reviews and discussions of some types of batteries for EV are contained by considering energy density and weight of the batteries. In addition, simulations of Li-Ion battery are accomplished with various variables such as temperature, capacity fading and charge/discharge current. It is confirmed that temperature is the main factor of capacity fading. Validation of the modeled battery is also conducted by comparing it with commercialized battery.