국내 전동차의 직선구간과 곡선구간에 따른 동적 시뮬레이션 승차감 평가

송태섭(Taeseop Song),이희성(Hisung Lee) 한국도시철도학회 2021 한국도시철도학회논문집 Vol.9 No.4

철도차량의 승차감은 승객의 안락도를 평가하는 척도이다. 국내 도시철도는 직선과 여러 곡선구간으로 이루어져 있다. 하지만 신조차량을 제작 시에는 형식승인과정에서 차량에 대한 직선구간의 승차감 평가만 적용되고 있다. 이에 본 논문에서는 국내 도시철도차량의 승차감 시험환경에 따라 동적 시뮬레이션으로 직선구간에 대한 승차감과 직선구간의 승차감 방법을 적용하여 곡선구간의 승차감 평가하고자 한다. The ride comfort of a railroad car is a measure to evaluate the comfort level of passengers. Domestic urban railways consist of straight lines and several curved sections. However, when manufacturing a new vehicle, only the ride comfort evaluation of the straight section of the vehicle is applied during the type approval process. Therefore, in this paper, the ride comfort in the curved section is evaluated by applying the method of riding comfort in the straight section and the ride comfort in the straight section through a dynamic simulation according to the riding comfort test environment of domestic urban railway vehicles.

곡선부 주행시 차량 승차감 분석

최일윤(Il-Yoon Choi),엄주환(Ju-Hwan Um),이준석(J S Lee),최민지(Min-Ji Choi) 한국철도학회 2014 한국철도학회 학술발표대회논문집 Vol.2014 No.5

철도선형 중 곡선구간은 직선구간에 비하여 상대적으로 주행안전성 및 승차감 측면에서 불리하다. 본 연구에서는 차체 횡방향 진동가속도 계측결과를 토대로 곡선부에서의 승차감을 계산하였다. 일반철도 곡선부에서의 횡방향승차감 분포수준을 관련 기준과 비교하였으며, 선로의 곡선반경 크기가 횡방향 승차감에 미치는 영향을 분석하였다. 또한, 차량의 주행속도에 따른 횡방향 승차감 분포특성을 조사하였다. Curved section of railway can be critical than tangent section in terms of ride comfort and running behavior of rolling stock. Ride comfort on the curves is investigated using the lateral acceleration measured on floor of car body. The influence of radius on ride comfort is investigated and the relationship between cant deficiency and ride comfort are discussed in brief. Finally, the distribution of ride comfort on the curve section is also discussed.

승차감 분석 및 객관평가 해법, 랜덤 노면 DRA

김승한(Seunghan Kim) 한국자동차공학회 2022 한국자동차공학회 학술대회 및 전시회 Vol.2022 No.11

Ride comfort is a performance that combines the human emotional response to the low-frequency behavior of the vehicle on the road. Subjective rating has been carried out in the vehicle development process, and due to the uncertainty of the subjective rating, there has been a limit in that it was not possible to quickly and clearly approach a solution for improving ride comfort performance. Ride comfort is the only performance index that is difficult to derive a solution directly from the commonly known task of measuring vehicle behavior. And ride comfort is a continuously difficult performance index in vehicle development as long as the vehicle is driving on the road. This paper proposes random road DRA as the solution for the analysis and objective rating of ride-comfort.

극치이론을 이용한 표본기반의 차량승차감 신뢰성 설계

최찬규(Chan Kyu Choi),유홍희(Hong Hee Yoo) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

The properties of the system parameters in a vehicle have uncertainties due to material irregularity, manufacturing tolerances or any other uncertain factors. Since the uncertainties of the system parameters lead to the uncertainty of the vehicle ride comfort, the uncertainties of the system parameters are direct causes of declining reliability of the vehicle ride comfort. So, the uncertainty of the vehicle ride comfort should be analyzed and considered for reliable design of the vehicle ride comfort. In order to analyze the uncertainty of the vehicle ride comfort accurately, exact probability distributions of the uncertain system parameters are needed. In most of practical situations, however, obtaining the exact probability distributions of the uncertain system parameters is almost impossible because of the limited time and cost. For that case, the reliability of the vehicle ride comfort cannot be obtained. Therefore, the reliability of the vehicle ride comfort should be estimated using limited samples of the uncertain system parameters. For the purpose, samplebased reliability estimation method employing an extreme value theory was proposed in this paper. Using the proposed reliability estimation method, reliability design of the vehicle ride comfort was conducted.

반응표면법과 유전자 알고리듬을 이용한 런플랫 타이어 최적화

최재형(Jaehyeong Choi),강남철(Namcheol Kang) 한국소음진동공학회 2015 한국소음진동공학회 논문집 Vol.25 No.4

Ride comfort is one of the major factors in evaluating the performance of the vehicle. Tire is closely related to the ride comfort of the vehicle as the only parts in contact with the road surface directly. Vertical stiffness which is one of the parameters to evaluate the tire performance is great influence on the ride comfort. In general, the lower the vertical stiffness, the ride comfort is improved. Research for improving the ride comfort has been mainly carried out by optimizing the shape of the pneumatic tire. However, demand for safety of the vehicle has been increased recently such as a run-flat tire which is effective in safety improvement. But a run-flat tire have trouble in practical use because of poor ride comfort than general tire. Therefore, In this paper, the research was carried out for improving the ride comfort through the optimization of the SIR shape inside a run-flat tire. Meta-model was generated by using the design of experiment and it was able to reduce the time for the finite element analysis of optimization. In addition, Shape optimization for improving the ride comfort was performed by using the genetic algorithm which is one of the global optimization techniques.

차체의 유연성을 고려한 고속철도 차량 승차감 해석

신범식(Bum-Sik Shin),최연선(Yeon-Sun Choi),구자춘(Ja-Choon Koo),이상원(Sang-Won Lee),이승일(Sung-Il Lee) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.4

고속철도 개발에 있어 승차감은 차량의 품질을 결정하는 중요한 요소이다. 본 논문에서는 고속철도 차량의 강체 및 유연체 모델 각각에 대해 속도증가에 따른 고속철도 차량의 승차감을 평가하였다. 가진원은 휠/레일 불균일에 의한 상하 진동만을 고려하였다. 속도 증가에 따른 차체의 진동을 계산하기 위해 강체 및 유연체 모델의 고유진동수와 모드형상을 계산하였다. 복잡한 형상의 압출재로 구성된 차체를 유연체로 모델링하기 위해 등가 물성치를 산출하여 등가 쉘로 모델링하였다. 계산된 차량의 진동으로 승차감을 평가한 결과, 강체 모델로 예측된 고속철도의 승차감은 고속에서 오히려 좋아지는 불합리한 결과가 도출 되었다. 반면 차량의 유연체 모드까지 고려하여 평가한 고속철도의 승차감은 속도 증가에 따라 승차감이 나빠지는 당연한 결과를 보여 주었다. 따라서 고속에서의 철도차량 개발은 차체의 유연체 특성을 고려해야함을 확인하였다. In the development of high-speed trains, ride comfort is an important factor that determines the quality of the train. In this study, the ride comforts of high-speed trains with rigid and flexible car bodies were evaluated. The rail irregularity is used as an exciting source of the car-body bounce motion. The complex extruded structures of the car-body are modeled as shell structures using the calculated equivalent stiffness of the flexible model. The numerical results show that the ride of the rigid-body model improves as the speed increases, which is unreasonable. In contrast, the relationship between ride comfort and speed in the case of flexible-body model is reasonable. Thus, it is confirmed that the flexibility of the car body needs to be taken into consideration while fabricating a high-speed train.

공리적 설계를 이용한 현가 장치 설계와 승차감에 관한 연구

김정훈(Junghoon Kim),강연준(Yeon June Kang),김강식(Kangsik Kim) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In the present study, a theoretical formulation based on the axiomatic design approach to suspension system is presented for improving both ride comfort and static design factors (SDFs) of the passenger vehicle. The design of a suspension system is affected by a lot of design parameters. The axiomatic design approach was adapted to the kinematic design of the suspension system to make a decoupled or less coupled relationship between the functional requirements (FRs) and design parameters (DPs) of the suspension system. SDFs which are related to wheel alignment and ride comfort are selected for the FRs and the position of the suspension hard points are chosen for common DPs. To mathematically express SDFs, the performance index is defined and the dynamic characteristics are analyzed for ride comfort evaluation using flexible vehicle body model of the commercial vehicle. The sensitivity matrices are defined between the FRs and DPs. The design sequences of SDFs are proposed by using these matrices with the vehicle model. Finally, by choosing independent DPs from the matrices of SDFs and sensitive DPs to ride comfort, specific DPs are applied to both ride comfort and SDFs. This study can be improved both ride comfort and SDFs by properly designing the kinematic design points.

설계변수의 산포를 고려한 차량 승차감의 강건최적설계

송필곤(Song, Pil-Gon),유홍희(Yoo, Hong-Hee) 한국소음진동공학회 2008 한국소음진동공학회 논문집 Vol.18 No.12

Vehicle vibration mostly originates from the road excitation and causes discomfort, fatigue and even injury to a driver. Vehicle ride comfort is one of the most important performance indices to achieve a high-quality vehicle design. Since design parameter variations inevitably result in the vehicle ride comfort variance, the variance characteristics should be analyzed in the early design stage of the vehicle. The vehicle ride comfort is often defined by an index which employs a weighted RMS value of the acceleration PSD of a seat position. The design solution is obtained through two steps in this study. An optimization problem to obtain a minimum ride comfort index is solved first. Then another optimization problem to obtain minimum variance of the ride comfort index is solved. For the optimization problems, the equations of motion and the sensitivity equations are derived basing on a 5-DOF vehicle model. The numerical results show that an optimal solution for the minimum ride comfort is not necessarily same as that of the minimum variance of the ride comfort.

공차의 영향을 고려한 차량 승차감의 강건최적설계

송필곤(Pil Gon Song),Maksym Spiryagin,유홍희(Hong Hee Yoo) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

Vehicle vibration mostly originates from the road excitation and causes discomfort, fatigue and even injury to a driver. Vehicle ride comfort is one of the most important performance indices to achieve a high-quality vehicle design. Since design parameter tolerances inevitably result in the vehicle ride comfort variance, the variance characteristics should be analyzed in the early design stage of the vehicle. The vehicle ride comfort is often defined by an index which employs a weighted RMS value of the acceleration PSD of a seat position. The design solution is obtained through two steps in this study. An optimization problem to obtain a minimum ride comfort index is solved first. Then another optimization problem to obtain minimum variance of the ride comfort index is solved. For the optimization problems, the equations of motion and the sensitivity equations are derived basing on a 5-DOF vehicle model. The numerical results show that an optimal solution for the minimum ride comfort is not necessarily same as that of the minimum variance of the ride comfort.

고속열차 좌석 및 입석 조건에 따른 승차감 평가

김덕만(Deokman Kim),김득하(Deukha Kim),최성훈(Sunghoon Choi),박준홍(Junhong Park) 한국소음진동공학회 2019 한국소음진동공학회 논문집 Vol.29 No.1

Various factors including vibration levels influenced ride comfort recognized by passengers during transits by high-speed trains. The vibration level was measured on the floor of the train. The measurement on the surface on the seat cushion and the seatback is also being considered for evaluations. The frequency weightings were applied to evaluate the ride comfort. In this study, three axis vibration on the passenger body was measured to analyze the human body vibration and its effect on the ride comfort. The vibration levels were measured for passengers in the seated and the standing positions. The vibrations of the seat and the human body were measured at constant speed of 300 ㎞/h. The frequency weightings defined in ISO 2631-1 were applied to the body vibration levels for finding the ride comfort. The ride comfort in the seated position was compared to that in the standing position using the proposed level. The comparison shows information about the importance of the vibration measurement locations for ride comfort evaluation.