• 한국기계기술학회지
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• 제13권3호
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• pp.57-64
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• 2011

Vibrations on the floor in a car are transmitted to the foot, hip, and back from the seat. Human body recognizes these vibrations, but the sensitivity for each vibration is different. To evaluate these vibrations, RMS(root mean square) of accelerations, VDV(vibration does value) are commonly used. The ride comfort evaluation is usually carried out by experiments of real cars which are expensive. The purpose of this paper is to briefly review the status of several ride vibration standards and criteria having relevance to construction machinery vehicles and to suggest recommendations for the effective use of such criteria in vehicle / component development.

• 한국철도학회논문집
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• 제11권6호
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• pp.543-549
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• 2008

철도 교통은 다른 교통수단에 비해 승객과 화물을 많이 수송할 수 있을 뿐만 아니라 안전성, 정시성(定時性) 및 환경 친화성 등의 장점을 갖고 있다. 철도를 다른 교통수단과의 경쟁력을 강화시키기 위해서는 열차의 속도 및 여객수송의 품질 향상 등이 필요하다. 특히, 승객이 여객수송의 품질에 대해 최종적으로 평가한다는 점을 감안할 때 승차감을 일정한 수준이상으로 향상시키는 것이 필수적이다. 일반적으로 철도차량에 대한 승차감은 차량의 진동 가속도를 측정한 후 인간의 등가 감응량으로 정량화시켜 평가하는 방법을 사용한다. 본 논문에서는 UIC 513R 규격에 따라 측정된 한국형 고속열차의 승차감 지수를 t-검정, 분산분석(ANOVA), 회귀분석 등과 같은 추리통계적인 방법론을 적용하여 분석 및 평가하고자 한다.

• 한국철도학회논문집
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• 제10권2호
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• pp.146-152
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• 2007

The ride comfort is more important in the train speedup. Generally, it is defined as the vehicle vibration. There are many studies on evaluation method of ride comfort for railway. But the ride comfort for Korean high speed train(HSR 350x) has been assessed by statistical method according to UIC 513R. It is impossible for HSR 350x to run at constant speeds above 310km/h during 5 minutes required in UIC 513R because of the same operational condition as KTX and the design limitation of infrastructures. The ride indices data had been acquired from 80 to 310km/h through the on-line test. The present study has suggested the methodology for the estimation of the ride indices at high speed above 310km/h by using those obtained below 310km/h and reviewed the ride comfort for HSR 350x in these speeds.

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.999-1006
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• 2004

Recently, the ride comfort problem becomes increasingly important because of today's needs for train speedup. The railway has the track irregularities which cause vibrations, such as rail joints, turnout, level crossing, transition corves and super-elevation ramps, and variations in the track level(z-axis) and the gauge(y-axis). In Korea, the service run of the high speed train has been made since the 1st of April, 2004. The commercial high-speed trains must be run on the compound lines which are composed of high-speed line and conventional line. The high speed lines in both Kyoungbu line and Honam line have 57.5％ and 33.8％, respectively In this Paper, the ride comfort has been reviewed by the various experimental methods when the high-speed trains are operated on both Kyoungbu line and Honam line. The results show that the high-speed train has no problems from the viewpoint of the comfort ride during the operation on the high speed line and conventional line.

• 한국자동차공학회논문집
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• 제8권3호
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• pp.171-180
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• 2000

This paper deals with the whole-body vibration and ride quality evaluation in the vertical direction. The responses of the floor, hip, back, and head in four subjects were measured for various seats when the floor was excited by random vibration with r.m.s of 1.2m/s2 in the vertical direction. In the transmissibility between the hip and floor, the fundamental mode is observed at 4.4 Hz. In the transmissibility between the head and floor, the fundamental mode at 4.4Hz and the second mode at 7.6Hz are observed. It is shown that the head motion is 41% larger than the hip motion and the response of female subject is larger than that of male subject. The response without backrest also was compared with that with backrest. From these human responses ride quality of five seats were evaluated by the ride value such as transfer ration having frequency weighting function is the statistical sense. It is observed that the seat having high damping property can reduce the most acceleration exposed to hip in the statistical sense for all ride valves, while the seat having different seat spring doesn't show statistical difference.

• 한국소음진동공학회논문집
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• 제27권2호
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• pp.162-167
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• 2017

The chevron rubber spring is used for subway vehicle as a primary suspension. Generally, the primary suspension has an influence to the running performance and not so much effect on the ride comfort in railway vehicle. But the stiffness of chevron spring is harder and harder as time goes on because of rubber characteristics. Therefore the dynamic characteristics such as ride comfort and derailment coefficient should be reviewed according to the stiffness variation of chevron rubber spring. In this paper the effect of chevron rubber spring on dynamic characteristics was studied by considering multi-body dynamics of railway vehicle on one straight line and seven curved lines.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.192-197
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• 2003

The ‘AEIPR’(Accelerometer Established Inertial Profiling Reference) method has been applied to measure the road profile. The dynamic road profiling method using AEIPR has the advantages of cost effectiveness, measuring speed and relatively high reliability. However, it is required to improve the double integration algorithm to get the measurement results with the accuracy of hither level. In the first part of this paper, the effective double integration algorithm is suggested and the ‘Road Profiler’ software is developed on the basis of the algorithm. Road profiling tests are performed using the developed ‘Road Profiler’ system on the specially designed tracks for the durability tests and the various types of pubic roads. Test results are shown and evaluated by the international road evaluation indicies and classification.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.780-787
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• 2013

Virtual Seat Method (VSM) is used in this study for a combined evaluation method (objective & subjective) to determine comfort value of passenger vehicle seat in terms of idle vibration. In the study, a process for applying VSM divided into two stages is established. Two kinds of seat mounting passenger vehicle and six subjects are employed to compare the comfort value obtained by VSM method and by SEAT value. As a conclusion, the results by the two methods were well consistent so that VSM is verified as a method to measure ride comfort of seat in terms of idle vibration at passenger vehicle.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.838-843
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• 2005

The nonlinear characteristics of a suspension is directly related to the ride quality of a passenger car. In this study, a dynamic experiment for a spring and a damper of a passenger car is performed to analyze the nonlinear characteristics using MTS 1-axial testing machine and a mathematical nonlinear dynamic suspension model based on experimental data is devised to estimate the ride quality using Billings' method. The devised nonlinear model is applied to the ride quality analysis using K factor and the effect of suspension parameters is examined. As a result, the friction between the cylinder and the piston of a damper is the most effective parameter for the ride quality of a passenger car.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(B)
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• pp.328-332
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• 2010

교통사고는 운전자, 차량, 주변 교통상태, 도로 및 교통시설 등의 여러 요인이 복합적으로 작용하여 발생하지만, 많은 경우 운전자의 운전 행태가 가장 큰 영향을 미친다. 본 논문은 이러한 운전자의 운전 행태를 분석하여 점수화 하여 보여줌으로써 운전 행태를 개선할 수 있도록 도와주는 정숙 운전 지수 표기기 개발에 관한 것이다. 연구에서는 MEMS 기반 3차원 가속도 센서와 3축 지자기 센서, GPS 등 모션 센서들을 이용하여 운전 안정성 / 승차감 지수를 측정, 저장하고 정량적으로 보여 줌으로써 운전자의 운전습관을 개선할 수 있도록 해 준다. 실제 구현에는 정숙 운전 지수 계산에 필요한 모든 센서를 이미 포함하고 있는 아이폰을 이용하였으나, 내비게이션 시스템이나, 차량용 블랙 박스 등에 최소한이 센서를 부가 장착함으로써 적용이 가능하다.