• Journal of the Korea Convergence Society
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• v.3 no.4
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• pp.35-44
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• 2012

In this study, a simulation program is developed in order to investigate non steady-state cornering performance of 6WD/6WS special-purpose vehicles. 6WD vehicles are believed to have good performance on off-the-road maneuvering and to have fail-safe capabilities. But the cornering performances of 6WS vehicles are not well understood in the related literature. In this paper, 6WD/6WS vehicles are modeled as a 18 DOF system which includes non-linear vehicle dynamics, tire models, and kinematic effects. Then the vehicle model is constructed into a simulation program using the MATLAB/SIMULINK so that input/output and vehicle parameters can be changed easily with the modulated approach. Cornering performance of the 6WS vehicle is analyzed for brake steering and pivoting, respectively. Simulation results show that cornering performance depends on the middle-wheel steering as well as front/rear wheel steering. In addition, a new 6WS control law is proposed in order to minimize the sideslip angle. Lane change simulation results demonstrate the advantage of 6WS vehicles with the proposed control law.

• KIPE Magazine
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• v.14 no.5
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• pp.36-41
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• 2009

전기철도차량에는 대용량 추진제어 컨버터/인버터부터 소용량 스위칭 모드 전원장치에 이르기까지 철도차량의 운행에 필요한 각종 동력 및 전력을 공급하기 위한 여러 가지 형태의 전력변환장치가 사용되고 있다. 그 중 가장 대표적인 전력변환장치가 추진제어인버터와 보조전원장치이다. 전기철도차량의 성능평가는 전력변환장치의 성능평가라 할 수 있을 정도로 많은 비중을 전력변환장치가 차지하고 있다. 한국철도기술연구원은 국토해양부로부터 지정받은 성능시험기관으로서 국내 도시철도 및 철도차량의 성능평가를 수행하고 있다. 성능시험은 차량의 제작공정에 따라 부품시험, 구성품시험, 완성차시험, 예비주행 및 본선시운전의 각 단계별로 실시하고 그 시험기준으로 도시철도차량의 성능시험에관한기준 및 철도차량성능시험 시행지침이 적용된다. 성능시험기준을 근간으로 추진제어인버터와 보조전원장치의 성능시험 대한 시험항목과 시험방법에 대하여 소개한다.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.636-639
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• 1997

In this paper, a dynamic control scheme is proposed which not only compensates for the lateral dynamics and longitudinal dynamics but also deal with the yaw motion dynamics. Using the dynamic control technique, adaptive and learning algorithm together, the proposed controller is not only robust to disturbance and parameter uncertainties but also can learn the inverse dynamics model in steady state. Based on the proposed dynamic control scheme, a dynamic vehicle simulator is contructed to design and test various control techniques for 4-wheel steering vehicles.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.2
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• pp.31-41
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• 1997

Equations of motion for a 7 DOF full car model is developed in detail and used for the design of LQR based active suspension system. The frequency response to road disturbance input and the motion of a car passing unequal bumps were used to analyzed the dynamic characteristics of the 7 DOF full car with passive or active suspensions. The resulting linear equations of motion may be usefull in designing other types of active suspension.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.702-707
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• 2000

Under the rapid change of a new vehicle model, it is necessary to develop a durability analysis technique using computer simulation. In order to do this. reliable dynamic stress-time history for the vehicle components must be calculated on various road conditions. In this paper, a full vehicle simulation model which is composed of flexible frame and chassis components is proposed and verified its reliability from the comparison with field test data. Finally, dynamic stress-time history on the rear chassis components is predicted with hybrid and modal superposition method.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.105-111
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• 1999

The paper presents development of a Hardware-In-the-Loop simulation (HILS) system for the purpose of testing performance, stability, and reliability of an electronic power steering system(EPS). In order to realistically test an EPS by the proposed HILS apparatus, a simulated uniaxial dynamic rack force is applied physically to the EPS hardware by a pnumatic actuator. An EPS hardware is composed of steering wheel &column, a rack & pinion mechanism, andas motor-driven power steering system. A command signal for a pneumatic rack-force actuator is generated from the vehicle handling lumped parameter dynamic model 9software) that is simulated in real time by using a very fast digital signal processor. The inputs to the real-time vehicle dynamic simulation model are a constant vehicle forward speed and from wheel steering angles driven through a steering system by a driver. The output from a real-time simulation model is an electric signal that is proportional to the uniaxial rack force. The vehicle handling lumped parameter dynamic model is validated by a fully nonlinear constrained multibody vehicle dynamic model. The HILS system simulation results sow that the proposed HILS system may be used to realistically test the performance stability , and reliability of an electronic power steering system is a repeated way.

• Archives of design research
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• v.17 no.3
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• pp.123-132
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• 2004

This paper shows a study on the "Korean High Speed Train Design" method, its design process and the result in the form of aerodynamic optimal exterior design development of a prototype test train(HSR 350${\times}$). It was developed from 1996 until 2002, six years long in R '||'&'||' D project titled "Development of High Speed Railway Technology" The end result of the project is a prototype test train, which has two power cars, two motorized trailers and three trailers, had been tested successfully in the year 2003 to the highest speed limit 380km/h on high speed line. The improved conceptual design work of a new commercial train and next generation's train is also performed for future needs.uture needs.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.903-912
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• 2009

This study is focused on simulation-based dimensional tolerance optimization process (DTOP) to minimize vehicle pulls by reduction of dimensional variation in front suspension system. In previous studies, the effect of tires and wheel alignment sensitivity have mainly been investigated to eliminate vehicle pulls in nominal design condition without allocating optimal tolerance level for selected components, among various factors regarding vehicle pulls such as vehicle design parameters, vehicle weight balance, tires, and environmental factors. Unfortunately, there are wide variations in the real vehicle, and these have impacted actual vehicle pulls, especially wheel alignment effects from suspension geometry variation has not been considered in the previous studies. In the tolerance design of suspension, tolerance variables with the uncertainty such as parts dimensional variation, assembly process, datum position and direction, and assembly tool tolerance has a great influence on the variation of the suspension dimensional performances. This study introduces total vehicle pull prediction model in considering major key factors for vehicle pull sensitivity. The Monte Carlo-based tolerance analysis model using Taguchi robust method is developed to optimize dimensional tolerance parameters, satisfying on the target variation level.

• Review of KIISC
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• v.33 no.4
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• pp.31-40
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• 2023

차량 기술의 발전으로 커넥티드 및 자율주행 차량 환경과 같은 차량 기술의 발전은 운전자에게 편의와 안전을 위한 기능을 제공한다. 하지만 이러한 장점들에도 불구하고 사이버 공격의 다양한 취약점 노출되어 있다. 최근까지 자동차 내부 네트워크로써 가장 널리 사용되는 통신기술인 CAN(Controller Area Networks) 통신은 대부분 차량의 동력을 담당하는 역할을 하다보니, 보안 문제의 중심에 서게 될 수 있다. 다양한 이기종 네트워크에서 구성된 가상화 기반의 사이버 훈련 프레임워크에 대해 설명하고자 한다. 이러한 사례 연구는 차량에 대해 물리적인 실험 환경에서의 모의침투와 같은 테스트가 어렵고, 보안과 안전이 함께 고려되어야 하는 특수성을 가진 차량 내부 네트워크의 사이버 훈련 프레임워크 설계에 도움을 줄 것이다. 본 논문에서는 가상화 개발환경 구축 사례 조사, 가상화 개발환경 구현과 차량의 공격 시나리오 및 탐지 프레임워크의 동향을 설명한다.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.455-460
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• 2003

180km/h 급 한국형 틸팅차량의 틸팅 메카니즘 기구동역학 해석을 통하여 얻어진 틸팅 대차를 형성하는 주요 파라메터들의 값을 기반으로 틸팅대차용 엑츄에이터의 성능과 용량을 계산하여 설계에 결과를 반영하고자 한다. 승객의 안락감을 유지하기 위해 차체 틸팅 각가속도에 Sine 연속 함수를 적용하여 차체의 틸팅 제어 패턴을 결정하였으며, 이를 통해 차체의 틸팅 각속도와 틸팅각의 패턴을 얻어내었다. 또한 이번 연구를 통해 틸팅 메카니즘의 파라메타를 변화하면서 각각의 틸팅각에 따른 Swing bar 와 엑츄에이터에 작용되는 반발력에 대한 영향력을 분석, 검토하였으며, 이에 따른 엑츄에이터의 출력과 변위 속도등의 변화를 조사하였다. 이러한 결과와 틸팅 메카니즘 기구동력학 해석의 결과를 토대로 틸팅차량이 요구하는 최적의 틸팅 운동을 수행하는 파라메타를 결정하였다.