• JOURNAL OF ELECTRICAL WORLD
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• s.241
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• pp.81-86
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• 1997

자동차의 배출가스가 가져오는 대기오염문제로 배출하지 않는 장점이 있는 전기자동차의 도입이 계획되고 있는 한편, 세계의 자동차관련메이커들은 꾸준히 개발$\cdot$개량을 추진하고 있다. 그 기술은 착실하게 진전되어 근거리역내에서의 교통수단으로서는 실용역에 이르고 있으며 앞으로 실용화를 위한 시험이 본격화될 것으로 보인다. 삼릉전기(주)에서는 보다 고성능의 전기자동차의 실용화를 위하여 유도전동기와 선진 구동제어 기술의 연구$\cdot$개발에 진력하여 유도전동기와 선진 구동제어기술을 조합한 구동시스템을 개발하였다. 유도전동기는 고속화, 냉각의 수냉화, 스테이터절연의 고내열화, 저손실코어재의 적용 등으로 소형$\cdot$경량화를 기하였다. 컨트롤러는 인버터의 파워소자에 구동$\cdot$보호회로를 내장한 IPM(Intelligent Power Module)을 채용하고 유도모터의 고효율화와 토크제어의 고응답$\cdot$고정도화를 양립시킨 고효율$\cdot$고응답벡터제어를 적용하였다. 또한 속도센서의 생략으로 코스트저감과 신뢰성의 향상을 위한 속도센서레스제어의 적용을 검토하고 있다. 이상으로 소형$\cdot$경량$\cdot$고효율$\cdot$저코스트를 조화시킨 고성능의 전기자동차구동시스템을 실현하였다.

• The KSFM Journal of Fluid Machinery
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• v.7 no.5 s.26
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• pp.43-49
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• 2004

A turbo blower, driven by a high-speed blushless DC motor, was designed as a efficient substitute of a ring blower or a roots blower. Computational analysis and performance tests have been performed to investigate performance characteristics of the blower. Experimental measurements showed that the blower has a good stability margin. This paper gives an outline of design, computational flow analysis and performance test for aerodynamic evaluation of the variable speed turboblower.

• Tunnel and Underground Space
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• v.32 no.5
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• pp.298-311
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• 2022

Some problems, such as aging workers, a decreased population due to a low birth rate, and shortage of skilled workers, are rising in construction sites. Therefore research for smart construction technology that can be improved for productivity, safety, and quality has been recently developed with government support by replacing traditional construction technology with advanced digital technology. In particular, the motor grader that mainly performs road surface flattening is a construction machine that requires the application of automation technology for repetitive construction. It is predicted that the construction period will be shortened if the construction automation technology such as trajectory tracking, automation work, and remote control technology is applied. In this study, we introduce the hardware and software architecture of the smart motor grader to apply unmanned and automation technology and then analyze the traditional earthwork method of the motor grader. We suggested the application plans for the path pattern and blade control method of the smart motor grader based on this. In addition, we verified the performance of waypoint-based path-following depending on scenarios and the blade control's performance through tests.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.3849-3855
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• 2012

This paper describes a control algorithm and test results of an automated manual transmission clutch actuated by a stepping motor. The control algorithm extracts driver's demand from CAN signals and decides the exact timing to engage or disengage the clutch based on the demand. A pulse signal is generated to drive the clutch and the travel of the clutch can be calculated by accumulating the pulse signal. An auto code generation method was introduced in implementing the control logic to the micro-processor of the prototype controller and a series of basic tests were carried out to validate its performance.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.691-700
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• 2017

This paper describes the design and implementation of automatic braille converter based on image processing for a person who is visually impaired. The conversion algorithm based on the image processing converts the input image obtained by the web-cam to binary image, and then calculates the cross-correlation with the stored character pattern image by labeling the character area and converts the character pattern image into the corresponding braille. The computer simulations showed that the proposed algorithm showed 95% and 91% conversion success rates for numerals and alphabets printed on A5 paper. The prototype test implemented by the servo motor using Arduino confirmed 89%, conversion performance. Therefore, we confirmed the feasibility of the automatic braille transducer.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.45-52
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• 2020

In this paper, a subminiature solid rocket motor(SSRM) was designed to develop a miniature smart-bullet and the designed propellant grain was made of thermoplastic propellant for production convenience of inner shape. The internal ballistics analysis and ground test were performed to investigate the performance of SSRM. And a numerical simulation was carried out to obtain basic data on the design of safety distance between the nozzle outlet and a gunner, the temperature distribution of exhaust gas was analyzed by comparing a numerical simulation and the results of IR camera.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.60-65
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• 2003

An experimental study was performed to understand ignition characteristics of gas turbine combustor with rotating fuel injection system. Liquid fuel applied to the inner surface of rotating fuel nozzle which was driven by high speed electrical motor is flung away by centrifugal forces. The real scale combustor and test rig was manufactured and tested under atmospheric condition in KARl combustion test facility. From the test results, this combustor ignition characteristics are highly dependent upon fuel nozzle rotating speed. Futhermore, combustor exit gas temperature was rapidly changed by increasing or decreasing the fuel nozzle rotating speed.

• Journal of Aerospace System Engineering
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• v.15 no.5
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• pp.43-49
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• 2021

This research shows how is designed, and its performance is evaluated on the ground for the VTOL drone before the flight test initiates. The targeted drone weight is approximately 45 kg including battery packs, and 4 motors are utilized to produce thrust and control directions. 30 min flight schedules were simulated to estimate the total power consumptions which result in 2.4 kWh. Then, two packs of 13-cells lithium-polymer battery with operating voltage ranging between 54 V and 44 V with up to 4 C-rate were fabricated to safely operate a VTOL drone. Moreover, the battery management system was installed to prevent over and under-voltage and over-current while running a battery system. To finally verify battery's performance, we conducted a ground evaluation for discharging battery tests at -10 ℃, 25 ℃ and 40 ℃, resulting in satisfying simulated power consumption conditions for flight schedules.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.3
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• pp.43-53
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• 2022

In this study, analysis of the flow characteristics of pintle-controlled nozzle with split-line TVC system and the thrust performance prediction was performed. The numerical computation was verified by comparing the thrust coefficient derived from the analysis results with the experimental data. By applying the same numerical analysis technique, the flow characteristics of nozzle were confirmed according to operating altitude, pintle stroke position and TVC angle with the 1/10 scale. As the TVC angle increased, thrust loss occurred and the tendency of AF was different depending on the position of the pintle stroke. Based on the analysis results, the relation of thrust coefficient was derived by applying the response surface methods. The thrust performance model with a slight difference of 1.2% on average from the analysis result was generated.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.5
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• pp.1-9
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• 2021

As part of the commercialization research of small gas turbine engines, starting and normal operation control logic research of small gas turbine engine was conducted. It was investigated how the igniter, starting motor and fuel pump/valve are controlled during the ignition and normal operation process and it was applied to the prototype engine control unit(ECU) of the small gas turbine engine for commercialization research. Based on the ground test results, an ECU for flight test is being developed, and after completion of the development, an altitude test will be performed through an altitude test facility of Korea Aerospace Research Institute.