• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1276-1281
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• 2006

In general, the wheel-skid prevention of braking system is very important in modern railway applications. This is because wheel-skid can lead to an increase in noise and vibration from wheels with flat points, as well as an increased braking distance. However conventional anti-skid control has problems because wheel adhension and skid characteristics are very difficult nonlinear systems and time consuming to accurately model. In this paper, we design a fuzzy controller using a model of relation between ahdension and braking force, we show that anti-skid fuzzy controller has a very good performance, performing better than the previous conventional controller.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권12호
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• pp.659-663
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• 2002

The brake systems of high-speed train are to be equipped with three different brake systems, such as regenerative brake with regenerative feedback in driving car, a pneumatic disc brake, and non-contact linear eddy-current brake(ECB). The regenerative brake and the pneumatic disc brake are acting on the wheels. Their achievable braking force depends on the adhesive coefficient, which is influenced by the weather condition and speed, between the wheel and The linear eddy current brake gets an economical solution in the high-speed train because of the independence of the adhesive coefficient, no maintenance needed. and the good control characteristics. The braking force and the normal force of ECB for korean high-speed train are analysed by the 2D FEM(Finite Element Method). Finally the normal force is compared with the experiential values to verify the analysis.

• Journal of Magnetics
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• 제18권3호
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• pp.276-282
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• 2013

In this paper, magnetic flux distributions of several permanent magnet arrays, including Halbach array, are analyzed and compared. Also, braking force characteristics on a moving solid conductor in the eddy current brake systems with such magnet arrays are analyzed. Then, a new performance index taking into account the maximum braking force and the volume of the magnet is introduced for the comparison and case study of permanent magnet arrays. By changing the lengths, magnetization directions and the height of the permanent magnet arrays, a higher braking force per volume of the magnet can be achieved.

• 한국정밀공학회지
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• 제12권12호
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• pp.81-90
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• 1995

Anti-lock Brake System has been developed to reduce tendency for wheel lock and improve vehicle control during sudden braking on slippery road surfaces. This is achieved by controlling the braking pressure avoiding wheel lock, while retaining handling and brake performance. This paper is concerned about characteristics of a solenoid valve in hydraulic modulator for controlling brake pressure. First, it was modeling the electromagnet by the permeance method. Second, it was modeling the commercial Maxwell poackage program. And then, a experiment was performed in order to justify modeling. The result of modeling coincided with teh result of experiment and commercial packabe program. As a result, these modelings will be able to use in analysis of dynamic character- istics of the solenoid valve for braking.

• 한국산학기술학회논문지
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• 제13권6호
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• pp.2428-2434
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• 2012

본 논문은 제동 시스템에서 전자식 주행안정 제어장치(ESC)의 유압 모듈레이터의 솔레노이드 밸브 제어에 대한 것이다. ESC의 전자제어유니트(ECU)를 제어하기 위한 방법으로 고주파수 제어와 슬로프 제어를 적용하였으며, 서지 압력 및 전자파간섭(EMI) 저감 특성을 연구하였다. 고주파수에서의 전자파 방출을 줄이기 위하여 ECU 출력 단에 슬로프 제어 기능을 추가하였다. 측정결과 제동 시스템에서 고주파수 ECU의 솔레노이드 밸브제어 방법에 따라 서지 압력과 전자파 방출이 저감될 수 있음을 확인하였다. 결론적으로 고주파수 ECU 제어 연구 결과에 의해 제동 시스템 성능을 향상방안을 제시하고자 한다.

• Tribology and Lubricants
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• 제28권3호
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• pp.112-116
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• 2012

wet-type multiple disk brakes are very important parts of turning decelerator for deck crane, because they are advanced in durability and braking power, and can be designed compactly. Thus, we designed and made wet-type multiple disk brakes of turning decelerator for deck crane to be localization of these imported all. In this study, wet multiple disk brakes were made a comparative test with the 2 types materials of friction disk by the SAE No.2 dynamometer. The friction characteristics were measured and analyzed to decide a suitable material as wear depth of friction disk and dynamic and static friction coefficient.

• Tribology and Lubricants
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• 제16권4호
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• pp.266-273
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• 2000

The friction characteristics of phenolic resin and model friction materials were investigated with the content of hexamethylenetetamine (HEXA). At 10 wt.% of HEXA, the phenolic resin and model friction materials showed the most stable friction coeffcient in constant temperature test at various test conditions because of its good thermal stability and proper curing reaction. It was found from constant interval test in mild condition that the friction coeffcients of friction materials cured with 10 wt.% of HEXA was the highest and stable values in the whole range of braking operations. However, at the severe condition in constant interval test, the friction coefficient of friction materials cured with 10 wt.% to of HEXA was lowered and as the number of braking operation increased, the values became stable. In order to obtain the thormal stable friction materials, the content of HEXA from 5 to 10 wt.% could be recommended.

• Tribology and Lubricants
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• 제25권6호
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• pp.381-386
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• 2009

In general, a brake system of axle for heavy duty machine as a wheel excavator makes use of wettype multiple disk brakes. These disk bakes are very important parts of heavy duty machine because they are dvanced in durability and braking power, and can be designed compactly. Thus, we adesigned and made wettype multiple disk brakes of axle for the wheel excavator to be localization of these imported all. In this study, wet multiple disk brakes were made a comparative test with the 3 types materials of friction disk by the SAE No.2 dynamometer. The friction characteristics were measured and analyzed to decide a suitable material as wear depth of friction disk and dynamic and static friction coefficient on temperature of oil and applied pressure.

• 오토저널
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• 제15권2호
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• pp.64-75
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• 1993

In this study, the function of a hydraulic brake system with a vacuum booster is systematically analyzed according to the mutual relations which follow : - the brake pedal force vs. booster cylinder input force - the booster output force vs. master cylinder input force - the hydraulic line pressure vs. braking deceleration. A computer program is developed based on the theory which is able to predict and analyze the pedal force characteristics at the beginning of the initial stage of brake system design. Analytical results show good agreement with the experimental vehicle test.

• 오토저널
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• 제8권4호
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• pp.56-65
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• 1986

This paper theoretically analyzed the relations between the out-put braking torque and the wheel cylinder pressure in the leading-trailing drum brake for heavy duty truck as the characteristics of friction in break lining, comparing with the results derived from full-scale inertial brake dynamometer test in actual braking condition to develop reliable brake system in extensive using conditions. The main results obtained are as follows; 1) The characteristic curve representing the relations between BEF (Brake Effectiveness Factor) and Friction coefficient derived from theoretical analysis are consistent with the experimental results of dynamometer test. 2) According to the results of dynamometer test, the friction coefficient of brake lining is subject to initial brake speed and the actual using temperature in brake system.