• 한국융합학회논문지
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• 제8권12호
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• pp.283-289
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• 2017

본 연구에서는 자동차 현가장치의 정적설계인자를 계산하기 위한 프로그램을 개발하였다. 이를 위해 기호계산기법을 사용하여 구속방정식의 자코비언에 대한 편미분을 계산하여 자코비언의 변형률 행렬을 유도하였다. 상용프로그램에서는 자코비언의 변형률 행렬을 계산하기 위하여 유한차분법 등을 사용하기도 하지만 본 연구에서는 이를 정확하게 고려하기 위하여 기호계산기법을 사용하여 계산하였다. 계산된 구속방정식 자코비언의 변형률 행렬을 사용하기 쉽도록 모듈화해 프로그램을 구성하였다. 계산된 자코비언 행렬을 사용한 결과를 1/4차량 더블위시본 현가장치에 대한 시뮬레이션을 통해 상용프로그램의 결과와 비교하여 정확성을 검증하였다. 향후 계산된 자세정보로부터 정적설계인자를 자동으로 추출하는 모듈과 함께 이를 이용하여 가상 테스트를 수행할 수 있는 융합 모듈을 추가할 예정이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.218-225
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• 2000

Recently, right rail transit (L.R.T.) systems become influential as a new traffic system in urban area to solve heavy traffic problems. However, there are little research results about the dynamic interaction problems between the vehicle and structural system, even though some studies far those static problems have been carried out. Therefore, first of ail, the dynamic equations of an interaction between vehicle system and surface roughness of the vehicle path are derived before developing the dynamic equations of vehicle-structure-surface roughness system, in this study. As a vehicle model, an automated guide-way transit (A.G.T.) system is adopted. Parametric study shows that the dynamic wheel loads of the vehicle system has a tendency to increase with vehicle speeds and stiffness of suspension system. However, those dynamic wheel loads have tendencies to decrease in according to loads of the vehicle system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.597-603
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• 2003

Air spring system in railway vehicles primarily ensure the air suspension of the vehicle body. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestic development productions are obtained the good results.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.247-259
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• 1996

Kinematic design sensitivity analysis for vehicle in suspension systems design is performed. Suspension systems are modeled using composite joins to reduce the number of the constraint equations. This allows a semi-analytical approach that is computerized symbolic manipulation before numerical computations and that may compensate for their drawbacks. All the constraint equations including design variables are derived in symbolic equations for sensitivity analysis. By directly differentiating the equations with respect to design variables, sensitivity equations are obtained. Since the proposed method only requires the hard point data, sensitivity analysis is possible in suspension design stage.

• 한국공작기계학회논문집
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• 제11권1호
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• pp.97-103
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• 2002

In the determination of control laws of semi-active suspension system, optimal control theory is applied, which used in the design of fully active suspension system and in the performance index sense. Optimal semi-active control laws are designed, and the computer program is developed fur estimation of performance In the time and frequency domain. It is certified that in the semi-active control system, it is desirable to minimize the spring constant and damping coefficient as possible in the given constraints. The effect of performance improvement which is almost equal to fully active type is obtained.

• Journal of Mechanical Science and Technology
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• 제17권12호
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• pp.1961-1968
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• 2003

In this paper, an efficient numerical algorithm for the kinematic analysis of the standard MacPherson suspension system is presented. The kinematic analysis of the suspension mechanism is carried out in terms of the rectangular Cartesian coordinates of some defined points in the links and at the kinematic joints. Geometric constraints that fix the distances between the points belonging to the same rigid link are introduced. The nonlinear constraint equations are solved by iterative numerical methods. The corresponding linear equations of the velocity and acceleration are solved to yield the velocities and accelerations of the unknown points. The velocities and accelerations of other points of interest as well as the angular velocity and acceleration of any link in the mechanism can be calculated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.543-546
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• 1997

The purpose of this study is to investigate the ERSU(Electr0-Rheological Suspension IJnit) and some progress of damping force characteristic of a ERSU. This paper describes overall construction of th'e system design and the manufacturing of ERSU. A model of the ERSU is made by using electric field dependent on Bingham properities of ER fluid. In this paper. the ERSU is designed and manufactured for a light ground tracked vehicle. From the results, it is shown that the damping performance of ERSLJ is better than that of a passive suspension unit. This experimental study might be very useful for the simulat~on and the design of semi-active suspension units.

• 동력기계공학회지
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• 제6권2호
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• pp.33-39
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• 2002

Commercial vehicles are mostly subjected to relatively rougher ground environment than passenger vehicles. Many driver's seats of commercial vehicles have suspension system with spring and dampers. Then, impact or vibrative forces transmitted from the vehicle to the driver can be attenuated. This study deals with a ride evaluation method using sky-hook control algorithm for the suspension dampers. Vibration amplitude transmissibilities were compared between passive dampers and semi-active dampers with sky-hook control method.

• 동력기계공학회지
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• 제3권3호
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• pp.91-96
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• 1999

This study is about the design and analysis ot a suspension damper for truck driver's seat to improve the ride comfort. Trucks are usually subjected to hostile driving environments. Therefore, many truck driver's seat have suspension seats to isolate the vibration from the cab floor panel. Because the vehicle suspension system can reduce the primary vibration from the ground, only low frequency vibration can be transmitted to the driver's seat. But, this low frequency vibration can be harmful to the driver. The seat damper is very critical element to improve the ride comfort for the driver. In this study, a four-stage damper is designed and analyzed for the vibration capability. The damping coefficient of this damper can lie manually controlled in response to the road and driving environment.

• 한국자동차공학회논문집
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• 제5권2호
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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.