• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.451-454
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• 1995

Increasing the transfortation efficiency is very important issue in railway system. Speed-up of train and shortage of headway can be its solution. Headway can vary with blocksection length, characteristics of the railway and signalling systems. Safety braking distance needed for passenger's safety is very important factor in block section division method. In this study, basic block section division program was developed with the differential ratio of braking distance resulted by grade value of the track. More complete block section division program is going to be developed by the help of experienced experts.

• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.623-640
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• 2017

The full nonlinear equations of an unmanned aerial vehicle ground taxiing mathematical dynamic model are built based on a type of unmanned aerial vehicle data in LMS Virtual.Lab Motion. The flexible landing gear model is considered to make the aircraft ground motion more accurate. The electric braking control system is established in MATLAB/Simulink and the experiment of it verifies that the electric braking model with the pressure sensor is fitted well with the actual braking mechanism and it ensures the braking response speediness. The direction rectification control law combining the differential brake and the rudder with 30% anti-skid brake is built to improve the directional stability. Two other rectifying control laws are demonstrated to compare with the designed control law to verify that the designed control is of high directional stability and high braking efficiency. The lateral displacement increases by 445.45% with poor rectification performance under the only rudder rectifying control relative to the designed control law. The braking distance rises by 36m and the braking frequency increases by 85.71% under the control law without anti-skid brake. Different landing conditions are simulated to verify the good robustness of the designed rectifying control.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.261-264
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• 1997

A contactless eddy current type braking system is developed to take advantages of the recent brake system which uses hydraulic force can show high efficiency in a certain velocity region, but not in a high velocity region, and has initial response delay time and pressure build-up time which make stopping distance longer. These are the limits of mechanical brake system of a contact type, which makes a concept brake system required. So, in this paper, the contactless brake system .of a inductive current type is chosen instead of hydraulic brake system. This brake system can be used almost forever for being no wear and contributed to lightening weight of a vehicle. Besides, the contactless brake system can be used as that of electric or solar car with anti-lock brake system. The analysis of induced electromotive force and braking torque obtained with theoretical approximate model, the design of a braking system and a nonlinear controller, and the results of simulation of the ABS, experiment are included.

• 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.

• 한국정보통신학회논문지
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• 제12권4호
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• pp.752-757
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• 2008

본 논문은 자동차의 정차 또는 주행 중 다양한 조건으로 제동 거리와 제동 안정성 시험을 할 수 있는 제동시험용 계측 S/W를 개발하였다. 본 논문에서 구현한 자동차 제동시험 용 계측 S/W는 제동시험에 대한 객관성을 확보하고, 제동시험에 대한 반복 재현성을 확보하여 현재 세계 각 국에서 실시하고 있는 다양한 제동 거리와 제동 안정성 시험에 적용할 수 있다. 자동차 제동시험용 계측기를 자동차에 장착하여, 정차 상태와 주행 중에 신차평가제도(NCAP)의 시험 조건과 자동차 제작사인 A, B사의 자체 시험조건에 맞추어 제동 거리와 제동 안정성 시험을 하였고, 모든 시험 조건에 맞는 시험을 할 수 있었으며, 보다 가혹한 시험 조건에도 적용해 봄으로써 차후 시험 조건이 변경 될 경우에도 본 논문에서 제작한 계측 S/W의 적용 가능성을 확인하였다.

• 센서학회지
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• 제16권1호
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• pp.68-76
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• 2007

In general, the braking system of a high speed train has an important role for the safety of the train. To stop safely the train at its pre-decided position, it is necessary to properly combine the various brakes. The train has adopted a combined electrical and mechanical (friction) braking systems. In order to design a good brake system, it is essential for designers to predict the brake performance. In this paper, the braking performance analysis program has been developed and verified by comparing the simulation results with the brake test results of HSR-350x; both results match very well. Also, the brake performances of high speed trains can be predicted by using this program under various conditions.

• 한국자동차공학회논문집
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• 제25권1호
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• pp.19-27
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• 2017

In this paper, a simulator hardware and control design for an electronic parking brake (EPB) are proposed for emergency vehicle braking when the hydraulic break and anti-lock brake systems (ABS) fail to function. EPB systems are designed specifically for park braking and are usually installed on the rear wheels. However, in an emergency situation when all vehicle brake systems fail, the EPB can be utilized to stop the vehicle and track the target slip ratio as the ABS. This paper analyzed the non-linear EBP of the type of motor on caliper (MoC) based on experiments. A simulator hardware is also designed to validate the performance of the designed EPB controller in terms of braking distance and performance in tracking the target slip ratio. Through the experimental analysis, it is confirmed that a sliding mode controller can be applied on a non-linear EPB to track the target slip ratio.

• 제어로봇시스템학회논문지
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• 제4권4호
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• pp.525-533
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• 1998

A conventional contact type brake system which uses a hydraulic system has mny Problems such as time delay response due to pressure build-up, brake pad wear due to contact movement, bulky size, and low braking performance in high speed region. As vehicle speed increases, a more powerful brake system is required to ensure vehicle safety and reliability. In this work, a contactless brake system of an eddy current type is proposed to overcome problems. Optimal torque control which minimizes a braking distance is investigated with a scaled-down model of an eddy current type brake. It is possible to realize optimal torque control when a maximum friction coefficient (or desired slip ratio) corresponding to road condition is maintained. Braking force analysis for a scaled-down model is done theoretically and experimentally compensated. To accomplish optimal torque control of an eddy current type brake system, a sliding mode control technique which is, one of the robust nonlinear control technique is developed. Robustness of the sliding mode controller is verified by investigating the braking performance when friction coefficient is varied. Simulation and experimental results will be presented to show that it has superior performance compared to the conventional method.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.238-241
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• 2008

A brake system in automobile is one of the important parts that directly affect the safety of passengers. Particularly, disk brake module is applied to almost all kinds of automobile brake system due to its remarkable braking power and braking distance. In the disk brake module of an automobile, the bolt for tire wheel is assembled to the disk brake hub by interference fit (bolt pressing process). The process induces small deformation whose range is within tens of ${\mu}m$ and this deformation may cause the runout badness of the whole disk brake module, and even braking problems such as judder or squeal phenomena which makes the loss of braking efficiency. In this study, bolt pressing fit into hub was simulated by $ANSYS^{TM}$, a commercial structure analysis program. Also, the aspect and the cause of hub displacement were analyzed and the solution for decreasing runout of hub was proposed.

• 대한교통학회지
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• 제30권5호
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• pp.83-90
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• 2012

운전자가 위급한 상황을 인지하였을 경우 일반적으로 가장 먼저 급제동 조치를 취하게 된다. 그렇기 때문에 교통사고 현장에서 가장 흔하게 볼 수 있는 흔적이 급제동흔적, 즉 스키드마크라 할 수 있다. 오늘날까지 스키드마크의 길이를 측정해서 사고 당시 속도를 추정하고 이를 통해 과속 여부를 판단하고 있다. 그러나 스키드마크의 길이를 통해 추정된 속도는 불완전 제동구간의 감속정도를 배제한 활주직전의 속도로써 제동직전 속도와는 다소 차이를 보인다. 최근 연구에서 제동직전 속도를 추정하기 위해 실차 실험을 통해 몇가지 방법이 제시되었으나, 물리적 원칙에 입각하여 제동직전 속도를 산정할 수 있는 근본적인 방법을 제시하지 못하였다. 그 중에서도 가장 핵심적인 사항이 불완전 제동구간과 활주구간의 감속도를 파악하는 것이며, 본 연구에서는 승용차와 대형차의 실차 급제동 실험을 통해서 불완전 제동구간과 활주구간의 감속도 경향을 분석하였다. 본 연구는 자동차의 실질적인 제동직전 주행속도를 산출할 수 있도록 기초정보를 제공하고 나아가서는 현행보다 과속 적용의 범주가 확대됨에 따라 운전자의 경각심을 유발하여 국가 교통사고 감소에 일조할 수 있을 것으로 기대된다.