• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권11호
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• pp.611-616
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• 1999

The introduction of the eddy current braking(ECB) system in HSRT(high speed railway train) is known to be advantageous, in that the system is independent on wheel-rail adhesion coefficient which is greatly affected by weather condition. It also minimize the maintenance of the brake system and does not require any additional electric energy because it is powered form the regenerated power at the time of the braking. In this study, the braking and attraction forces of the ECB are simulated by 2-D FEM and are experimentally verified on a down-scaled prototype. A control algorithm of the ECB is proposed to generate constant braking torque using linear variation of the reference current according to speed. Experimental results shows that the constant torque is generated over all operating speed region by developed control algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2745-2747
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• 1999

Recently, the eddy current braking system has an advantage as the high speed railway train is developed. Because it is independent on wheel-rail coefficient of adhesion and it can be used in adverse weather conditions by reason of non-acting on wheels. In this paper we designed down-scaled eddy current brake model and developed control algorithm to generate constant braking torque. Our algorithm is verified through experiments to generate constant torque.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.424-428
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• 2004

A wind turbine system converts wind energy into electric energy, the system operated under normal environmental conditions. In case of particular turbulent wind flow such as typhoon, hurricane etc, the control of a blade used to a yaw control and a pitch control method. A small wind turbine has not a speed control system to only a manual tail safety brake. This paper shows a automatic tail safety brake controller based on feedback control using wind velocity. The controller composed of wired motor, relay system, steel wired motor him down a perpendicular to wind flow and then the blade speed reduced high to zero. The operation of automatic tail safety controller verified by manual test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.68-70
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• 2006

This paper formulates the principle of the magnetic actuator break system (MASS) for emergency situation driving a car. When the exciting break system of a car is broken, MASS will be able to stop the car by the electric system. MASS controls the rotating wheel to slow down gradually while holding and laying the wheel down several ten times per second. We present the magnetic field and dynamic behavior analyses for the magnetic actuator break system using finite element method (FEM) associated with parameter, for calculating the displacement of the moving parts and the supplying current.

• 한국항공운항학회지
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• 제19권2호
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• pp.58-63
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• 2011

A Continuous Descent Approach(CDA) is defined as a simple, cost-effective, noise and emission abatement technique for any powered aircraft on approach. CDA also can be optimised within energy, speed and safety constraints by avoiding unnecessary flap, air brake and engine thrust. This study includes comparison on fuel consumption between Continuous Descent type and Step Down type by using flight data. In particular, we investigated fuel flow per hour, calibrated airspeed and pressure altitude for all flight time. During descent flight, the fuel consumption of Continuous Descent type was less than the fuel consumption of Step Down type.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.361-364
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• 2005

Some bogie frames manufactured in 1999, 2000 year have the fatal problem. Three or four years later, the cracked end beam among them have discovered in 2002, 2003 year. The crack situation of the end beam have a bad effect on brake system. In that case, the cars would be in danger of derailment. To improve the end beam, a research of covering the whole field of welded type bogie frame was started. Main line real tests were performed at Young-Dong line. The stress of main positions for bogie frame was measured. Also up-down direction and left-right direction vibration acceleration of the bogie frame were measured. At this time the tests were performed for the three types bogie. The test result concludes that the crack cause of the end beam is not brake load but vibration at running mainly. It is estimated that the life of the improved car which end beam reinforced is safe within the car permitted life(25 years). The improvement methods of the end beam are presented by construction modification, parts modification. The integrity evaluation is inspected by analysis the real line test results, the improvement methods of the end beam.

• 디지털융복합연구
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• 제13권11호
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• pp.171-178
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• 2015

디스크 커버는 브레이크 디스크 및 캘리퍼를 보호하기 위해 설치하고, 고객에게 인도되기 직전에 제거된다. 본 연구에서 디스크 커버의 온도는 주행 시험 차량(2000cc, 디젤)을 대상으로 측정되었다. 주행 시험(120km/h-제동(0.3G)-정지-120km/h-제동(0.5G)-정지)에서 측정된 최고 온도는 디스크 커버 상부에서 $260{\sim}270^{\circ}C$이었고, 디스크 커버 주위에 상당한 변화를 보였다. 이는 고온 디스크로부터 커버로의 주요 열전달이 대류를 통해서임을 커버 주위의 온도 분포로부터 추론 할 수 있다. 즉, 마찰 제동에 의해 발생된 고온의 공기가 디스크 커버 상부까지 올라간 것이다. 그리고 주행 시험 중에 디스크 커버의 상부 영역만이 용융되었다. 디스크 커버의 두께를 0.7mm부터 1.0mm로 증가시키고, 마스킹 테이프 1장을 디스크 커버 상부 영역에 부착하였다. 그 후에 디스크 커버는 주행 시험 시 마찰 제동에 의해 형성된 고온의 공기에도 변형되지 않았다.

• 동력기계공학회지
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• 제13권6호
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• pp.102-109
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• 2009

A retarder, as a supplementary brake system that is not friction-based, is frequently used in heavy-duty vehicles generally to slow the vehicles down on inclines. The electric retarder mainly used in a heavy-duty bus is generally placed between the transmission and the axle. The rotor inside the retarder system is attached to the axle. The operation of the retarder within a driven vehicle generates reverse torque due to coast driving force on hypoid gears in the differential gear system. By the reverse torque, scoring or scuffing on the hypoid gear teeth may directly occur. The scoring may be generated due to excessive contact stresses on the tooth surface. In this study, tooth contact stresses and contact patterns were analysed in order to investigate on the tooth scoring phenomenon using a finite element analysis program T900 in which the Hertzian contact stress formula was taken. Backlash, wear and surface finish were considered in the finite element simulation on the scoring.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.281-285
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• 1990

Our N.C. sewing machine is a device that acts sewing automatically in reference to N.C. data made by data input device. Our N.C. sewing mechine is composed of induction motor that has electric clutch and brake, step motor that drives x-y table. Sewing area of our machine is 170 mm * 100 mm, maximum sewing speed is about 2000 spm, maximum stitch length 6.2 mm. In actual sewing, synchronization between motion of needle up-down and motion of x-y table is a critical factor. In this paper, technology about synchronization will be profoundly discussed.

• 한국자동차공학회논문집
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• 제8권2호
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• pp.92-101
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• 2000

The objective of this paper is to design the controller for longitudinal vehicle following which makes the vehicle follow the lead vehicle and keeps a safety distance without human driver operation. This paper presents a sliding mode control algorithm for the ACC system. The controller is based on three sliding surfaces. Each surface plays an individual control-deviation control, throttle control and brake control. In addition to sliding mode control, we propose some additional schemes to enhance controller performance. The first one is a gear shift-down controller which makes tractive force increase with a change of gear ratio. The other is a predictive correction method which reduces slinky effect.