• Title/Summary/Keyword: special vehicles

Search Result 207, Processing Time 0.024 seconds

Measurement and Analysis of Transient Voltage for an Inverter-fed Induction Motor (인버터 구동 유도전동기에서 과도전압의 측정과 분석)

  • Kil, Gyung-Suk;Rhyu, Keel-Soo;Park, Dae-Won;Cho, Young-Jin;Cheon, Sang-Gyu;Choi, Su-Yeon
    • Journal of the Korean Society for Railway
    • /
    • v.10 no.6
    • /
    • pp.650-654
    • /
    • 2007
  • Induction motors are widely used as a source of driving force in electric vehicles and pulse width modulation (PWM) inverters are applied to their operation. The issue is that insulation of inverter-fed induction motors (IFMs) are more stressed than in line-powered motors by transient voltages. This paper dealt with experimental results on transient voltage produced by the PWM operation of an induction motor. The peak and the dv/dt of transient voltage depending on the length of power feeding cable and operating frequency were investigated. In the experiment, transient voltages up to 3.3PU of the rated-inverter voltage were recorded for the cable length of 50m. As the cable length is increased, the peak voltage appeared at the motor terminals increases. This phenomenon can be explained by the reflection and the transmission of travelling wave. Consequently, special care for the cable length between the motor and the inverter should be taken in the use of IFM to ensure the full life of insulation system.

Development of Road traffic Air Diffusion Simulation System using Graphic User Interface (GUI) (그래픽 유저 인터페이스(GUI)를 이용한 도로의 대기확산 예측시스템 개발)

  • Lee, Hwa-Woon;Oh, Eun-Joo
    • Journal of the Korean earth science society
    • /
    • v.24 no.5
    • /
    • pp.411-419
    • /
    • 2003
  • The assessment of environmental impact on NO$_2$ (or TSP) emitted by vehicles is important for local residents from the point of view of their health and environmental protection. In the course of field investigations, correct concentrations are measured and meteorological data are observed for numerical simulation. To determine background concentration for numerical simulation, annual average concentrations of NO$_2$ (or TSP) are estimated using the Puff-Plume model. If the estimated result affects the environment, it must be considered in the environmental conservation activity. To make the process of a estimation of environmental assessment more easily, this system is developed. Moreover, this system was supplied a Graphic User Interface (GH) for the user who calculated the concentration of air pollution exhausted from the traffic on general roads except special roads such as interchanges and entrances to tunnels. This system can offer not only the numerical result but also a graphic display. Even a beginner who is not a professional programmer can calculate the result easily.

An Adaptive Incentive/Topology Control Scheme for Stimulating Real time Data Forwarding in VANET Environment (VANET 환경에서 실시간 데이터 포워딩 진작을 위한 적응형 인센티브/토폴로지 제어 기법)

  • Bae, Seo-Yun;Kim, Nak-Myeong
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.48 no.7
    • /
    • pp.1-8
    • /
    • 2011
  • Vehicular Ad-hoc Network (VANET) is a special form of Mobile Ad-hoc Network designed to provide communications among nearby vehicles without communications infrastructure. Some characteristics in VANET environment such as high mobility, dynamic topology and selfishness of nodes can cause degradation of network quality. In this paper, we propose an adaptive incentive/topology control scheme to improve network quality in VANET by stimulating real time data forwarding and reporting changes of network topology. In the proposed scheme, an incentive suggested by the source node is updated in real time simultaneously with data transmission to stimulate real time data forwarding. In addition, when the order of the nodes in the path is changed, nodes which report the changes of network topology will get an additional incentive. By computer simulation, it is shown that the proposed incentive/topology control scheme outperforms the conventional schemes with respect to data delivery time and data delivery ratio.

Properties of CFRP by VaRTM Process and Its Application to Automobile Engine Hood (VaRTM 공법에 의해 제조된 CFRP의 특성평가 및 자동차 엔진 후드에 응용)

  • Kim, Y.H.;Choi, B.G.;Son, J.H.;Cho, Y.D.;Eum, S.H.;Woo, B.H.
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2005.06a
    • /
    • pp.377-381
    • /
    • 2005
  • The using of composite material is an aviation field but it changes into a general industry. Especially composites are expanding the use on transportation vehicles like automobiles, ships, and aircraft. The main factor of this expansion is high specific strength. It can supply a high quality and efficiency of energy. But manufacturing of composite products requires many raw materials and tooling cost for special process, so we needs a reduction of these costs to achieve best efficiency. In the present study, we contrast the change of mechanical and physical properties between VaRTM(Vacuum Assisted Resin Transfer Molding) and hand lay-up process. VaRTM process can offer a high quality the same as autoclave products, and low cost like hand lay-up process. In the results of mechanical tests, VaRTM specimen is stronger than hand lay-up specimen and hand lay-up specimen became delamination. In the results of physical tests, the resin content of VaRTM specimen is lower than hand lay-up specimen. On micrograph, the strength of specimen by VaRTM between fiber and resin is stronger than that of one by hand lay-up. And the specimen by hand lay-up contains more defects than one by VaRTM. So, VaRTM process can practically apply for automobile engine hood. This paper shows that VaRTM process is one of the most suitable processes for composite parts of automobile.

  • PDF

Design for Automated Roadside Parking Management System (무인 노변주차 관리시스템 운영방식 및 설계)

  • Nam, Doo-Hee;Lim, Kwan-Su
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.8 no.3
    • /
    • pp.20-26
    • /
    • 2009
  • One way to increase public revenue from public parking spaces is by improving the way parking meters gather data. Improved parking meters have evolved that increase car park revenue as well as efficiency in service and operations. It provides parking meters with the capacity to provide real-time information. This information consist primarily of the status of parking spaces (it indicates which expired metered spaces have parked vehicles.) The technology consists of sensors located at meters that report on their condition (i.e. whether it is working or if it is expired). This information is processed by a microprocessor and then sent via an internal wireless modem to the server. This server then processes the information from all the parking meters and sends it to the public institution in charge of them. This system also provides verification of parking permits. For example, disabled people with special license plates can be automatically approved for parking in designated places.

  • PDF

Detection of Misfire in Car Engines using Walsh Discrete Fourier Transform (WDFT를 이용한 자동차 엔진의 실화검출)

  • 김종부;이태표;오정수;임국현
    • Journal of the Korean Institute of Telematics and Electronics T
    • /
    • v.35T no.1
    • /
    • pp.67-74
    • /
    • 1998
  • The primary cause of air pollution by vehicles is imperfect combustion of fuel. One of the most usual causes of this imperfect combustion is the misfire in IC engins. The U.S. EPA(Environment Protection Agency) and the CARB(California air Resources Board) have imposed regulations for the detection of misfiring in automotive engines. The OBD-II regulations require that misfire should be monitored by the engine diagnostic system, and that the goal of OBD-II is to alert the driver to the presence of a malfunction of the emission control system. Several solutions to the misfire detection problem have been proposed for the detection of misfires. However, the performance of these methods in the presence of misfire is not altogether clear. This paper presents a precise method and system for internal combustion engine misfire. Present invention based upon measurements of engine roughness as derived from crankshaft angular velocity measurements with special signal processing method. Crankshaft angular velocity signals are processed by WDPT, so that the more reliable misfire detection than the time domain analysis. Experimental work confirms that it is possible to apply the WDFT for the detection of misfires in no-load idle and road testing.

  • PDF

Prevention of Women's Crime Using Autonomous car & Drones of Smart Police Efficient Multicasting Environment (스마트치안에서의 자율주행차 및 드론을 활용한 여성 범죄 예방 연구)

  • Kim, Seung-woo;Jung, Yu-jin
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.22 no.10
    • /
    • pp.1294-1299
    • /
    • 2018
  • 'SMART Police' means collecting, analyzing and utilizing the police database such as crime statistics, reflecting 'strategic management', 'analysis and research', 'science technology' do. In recent years, the number of sex offenses has more than doubled based on the 'crime analysis' of the Supreme Prosecutors' In this trend, we started to build a sex crime prevention program for women 's relief special 3.0 which is suitable for regional characteristics. However, it was not enough for the women to have low publicity and utilization results, and to show the practical effect. In the future, we propose a crime prevention system which can safely take home safeguarding with autonomous driving car or drone by applying ICT to the future police system. Although it is difficult to operate autonomous vehicles and drones in the surrounding environment such as narrow alleys and power lines for application to this system, it is thought that the artificial intelligence technology can be sufficiently overcome to operate.

Development of Fire Extinguisher Valves for Tracked Vehicle Using Novec1230 (친환경 소화약제 Novec1230을 적용하는 궤도차량용 소화기밸브 개발)

  • Kim, Jong-Ryeol;Ku, Hak-Keun;Oh, Sang-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.12 no.4
    • /
    • pp.1539-1546
    • /
    • 2011
  • Halon which is one of the typical fire extinguishing agents for special purposes was banned not only to use but to manufacture because it destroys the earth's ozone layer. There have been many efforts to find or create Halon alternatives and Novec1230 which is one of the eco-friendly fire extinguishing agents is nominated. In this paper 6 kinds of valve structures were suggested to apply Novec1230 to fire extinguishing agents for railroad vehicles as Novec1230 needs different valve specifications from Halon and spray shapes and action time were compared and measured. As the results, the extinguishing times of A type and F type valves are 20% faster than the other 4 types, and 178% faster than MIL-DTL-62547(USA). Therefore, they can be suggested to the eco-friendly extinguishing agents and Novec1230.

Influence of Vehicle Vibration on Track Geometry Measurement (차량 진동이 궤도 선형 측정에 미치는 영향)

  • Bae, Kyu-Young;Yong, Jae Chul;Kim, Lee-Hyeon;Kwon, Sam-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.26 no.6_spc
    • /
    • pp.644-650
    • /
    • 2016
  • Track maintenance works based on track geometry recordings are essential to enhance the safety and comfort of railway transportation. Usually, the track irregularity has been measured by a special inspection trains which all were imported from abroad. Because the inspection train speed is limited under 160 km/h, it takes a long time to inspect railways and there is difficulty in daytime operation. To solve this problem, we started to develop a track geometry measuring system (TGMS) with measurement speed up to 300 km/h which can be installed in commercial vehicles such as HEMU-430X. In this paper, we introduce a newly developed inertial TGMS and propose two inertial navigation system (INS) algorithms (method A, B) for measuring track geometry. In order to investigate advantage and disadvantage of each algorithm, we performed vibration test of the TGMS, which was simulated by 6-axis shaking table. Through the vibration test, we analyzed the influence of vehicle vibration on the TGMS which will be installed on bogie frame. To the vibration test, two methods satisfied the required accuracy of track geometry measurement under the level of the actual vehicle vibration of HEMU-430X train. Theoretically, method A is sensitive to vehicle vibration than method B. However, HEMU-430X's bogie vibration frequency range is out of interest range of measurement system. Therefore, method A can also apply the HEMU-430X train.

A Study on the Development of Calculation Tables and Formulas for Determining Separation Distance in Case of Cl2・HF Tank-lorry Leakage (염소・불화수소 탱크로리 누출사고 시 이격거리 산정을 위한 산정표 및 산정식 개발 연구)

  • Jeon, Byeong-Han;Kim, Hyun-Sub;Lim, Sang-Min;Lee, Joo-Chan;Lee, Gang-San
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.22 no.4
    • /
    • pp.212-219
    • /
    • 2021
  • Chemical accidents caused by transport vehicles account for 20% of all chemical accidents every year, but there are difficulties in the accident-response process due to repeated situations where the impact assessment information is unknown. In this study, we developed a calculation table and formula for predicting the range of damage for chlorine and hydrogen fluoride, which have a high domestic usage, high risk of accidents, and high accident frequency in the last 7 years. The calculation table is based on the leakage rate, wind speed, and temperature, and the calculation formula was derived using R software for special situations where it is difficult to apply the calculation table. The calculation table and formula could be used on site by related organizations to obtain important information for decision making, which could help in minimizing damage from chemical accidents, setting separation distances, and deciding to evacuate residents.