• 자동차안전학회지
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• 제16권2호
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• pp.14-19
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• 2024

This paper describes autonomous emergency braking systems (AEB) for elderly drivers designed to consider their driving characteristics. With aging, perception-reaction time, and decision-making time increase accordingly. Without being aware of these performance degradations, however, changes in driving patterns due to increased alertness while driving lead to vehicle crashes. Therefore, it is necessary to develop an autonomous emergency braking system by incorporating the characteristics of the elderly driver. In order to enhance the driver acceptance of older people, perception-reaction time, alertness, and ride comfort need to be considered for conventional autonomous emergency braking systems (C-AEB). Proactive AEB(P-AEB) algorithm has been proposed to reflect human factor of elderly driver above. The performance of the proposed algorithm has been evaluated through MATLAB simulink simulation studies. It has been shown from the computer simulations that the proposed P-AEB algorithm enhances the driver acceptance of older people by improving ride comfort while ensuring safety of vehicle.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.290-292
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• 1995

In this paper, the regenerative braking control system for 4 WD Electric Vehicle (EV) is proposed. Many studies on efficient drive of EV are being done to prolong the one charge distance. By using the regenerative braking (REGEN), the resulting EV system has following advantages : a) battery is recharged with the mechanical energy of EV, b) the running load can be reduced, and consequently the efficiency can be increased. The problem of REGEN that the power acceptance ability of battery is limited can be solved by controlling regenerative braking torque. The proposed control system has following characteristics. : a) It controls regenerative power by varying mechanical braking torque. b) It controls mechanical braking torque using load torque observer. c) It controls the regenerative braking torque independently. The control scheme and simulation results are presented for the experimental car.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1866-1870
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• 2008

In this paper, electric braking performances of linear induction motor(LIM) designed for propelling the MAGLEV are presented. Regenerative braking is carried out from 110km/h to 20km/h, and plugging which converts the direction of travelling magnetic field is carried out in the low speed region below 20km/h. It is important to reduce attractive force which can affect the magnetic levitation load during regenerative braking or plugging operation mode. So in this paper the braking performances are analyzed by finite element method. As a result, braking force, attractive force, phase current, voltage to frequency patterns and its magnetic fields of braking LIM are presented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.377-382
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• 2003

In tread braking of freight cars, braking force is produced by the friction between the wheel and the braking shoe. Friction coefficients such as the brake power, weight variation and brake shoe types should be sensitively treated as the design parameters. The conditions of the car, empty and weighted, should also be taken into consideration in brake force design and the control of brake force has some limitations in terms of the brake system design so that the brake materials selection should be considered as important measures to solve that difficulties. Friction characteristics of brake materials should remain within the range of maximum and minimum value and the friction performance should remain stable regardless of braking time and temperature. This study presented an experimental evaluation method to secure optimum braking performance by keeping safe braking effect and braking distance by the friction coefficient of the brake shoe of the freight cars.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.91-93
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• 1998

This paper describes the braking performance of the eddy current brake for high speed trains according to the number of poles. The eddy current brake systems have to be equipped with the maximum braking force and deceleration in the given volume or mass, high braking force rate, as small normal forces as possible and stable construction. The parameters, such as the number of poles, electric ampere turns, slot width have influence on the braking force characteristics. In this paper, the effect of braking performance from the variation of the number poles is calculated by using FEM, the number of the pole which makes the maximum braking force is proposed.

• 한국산학기술학회논문지
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• 제19권12호
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• pp.887-895
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• 2018

본 논문은 수송량 증대를 위한 열차제어시스템의 안전거리 설계와 전동차 제동설계에 활용할 수 있는 제동모델을 제시한다. 제동모델을 위해 6량 1편성으로 운행되는 전동차의 제동특성을 시험하였다. 제동특성에 영향을 줄 수 있는 인자로는 마찰계수, 제동압력의 변화, 회생제동 등이 있으며 시험을 통해 확인하였다. 제동압력은 상용제동과 비상제동으로 구분하고 차량의 특성을 반영하였다. 주행하는 철도차량에 작용하는 외력은 주행저항을 측정 시험과 후처리 방법을 제시하고 있는 KS R 9217에 따라 시험을 수행하고 2차 다항식 형태로 해당 열차의 주행저항을 제시하였다. 차량의 재원, 마찰계수, 제동압력, 주행저항을 바탕으로 직선 평탄 선로를 주행하는 전동차의 동적 거동은 다물체 동역학 해석 소프트웨어를 이용하여 해석하였다. 해석결과는 상용제동과 비상제동에 대하여 시험결과와 비교 검증하였으며 상당히 합리적인 결과를 도출하였다. 검증된 모델은 제동초기 속도에 따른 정지거리를 분석하고 감속도 중심의 제동모델과 비교하였다. 또한, 운영기관의 마찰계수 한계치에 따라 열차제어시스템을 위한 안전거리는 변화할 수 있음을 확인하였다. 본 연구의 결과는 철도차량들을 연결하여 운행하는 열차의 동적 거동해석에 활용할 수 있을 뿐 아니라 차량 설계에서 제동에 영향을 미치는 다양한 선로환경 분석과 제동 성능향상의 기초자료로 활용할 수 있을 것으로 기대된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1394-1400
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• 2003

Tire subjected to inflation pressure and the load of passenger car has a important roll to dynamic performance characteristics of radial tires such as cornering and braking. These performance characteristics are directly related to the belt cord durability of tires. In this paper, we analyze the mechanism of belt cord broken due to cord tension at braking theoretically.

• 한국자동차공학회논문집
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• 제24권6호
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• pp.635-641
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• 2016

Regenerative braking performance of an electrically powered vehicle is closely related to driving distance per battery charge. An electric vehicle uses appropriate amounts of mechanical braking force and electromagnetic regenerative braking force to recover energy and increase driving efficiency. In particular, when it drives on a downhill road, energy recovery rate is maximized through regenerative braking during coasting based on the mass inertia of the vehicle. Since an electric two-wheeled vehicle covered in this paper is lighter than an electric four-wheeled vehicle, the improvement of its driving distance per battery charge through regenerative braking is different from an electric four-wheeled vehicle. This study compared the driving characteristics of an electric two-wheeled vehicle based on regenerative braking. Two driving test modes were simulated with a chassis dynamometer system. By analyzing the measurement of a chassis dynamometer, the driving characteristics of a two-wheel electric vehicle, such as driving efficiency, were analyzed. In addition, test results were reviewed to draw the limitations of conventional test methods for regenerative braking performance of an electric two-wheel vehicle.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.1-5
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• 2005

High-speed trains with maximum speed of 300km/h, named KTX, have started revenue services since April 2004. Is becoming big problem where currently the KTX train because excessive braking noise at a station platform. The KTX braking noise follows in operating mode of KTX train and important railroad station where the quality appears different, the quality against hereupon from the commerce vehicle from the research which it sees it executes and comparison to analyze.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.554-559
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• 2011

Braking performance of a trainset that consists of a locomotive and several coaches and/or wagons is influenced by that of the locomotive as well as each coach or wagon. For trains to safely travel on a railway, trains must be provided with sufficient distance where to stop. Thus, replacing coaches or wagons needs calculating, measuring the braking performance such as a stopping distance or a deceleration. The task is further complicated if there are many kinds of trains with different braking performance characteristics. The accurate calculation is subject to acquire accurate information on the existing cars. Moreover, the initiation of braking by a driver or the geometry of the track affects as complicated factors. In this paper, based on the braking performance test conducted for US-SCRRA coaches, introduced several factors assumed to influence the result and the compensating methodology.