• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1721-1726
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• 2004

The studies of the half active suspension have been performed using various suspension models. In the early days, the modeling considered the inputs to the active suspension as the linear forces. Recently, due to the development of new control theory, the forces input to the half car active suspension system has been replaced by an actual input to the hydraulic actuators. Therefore, the dynamic of the active suspension system now consists of the dynamic of half car suspension system plus the dynamic of the hydraulic actuators. This paper proposed a new modeling technique in integrating both dynamic models. The proportional integral sliding mode control technique is utilized to control the hydraulically actuated of the half car active suspension system. The performance of the half car hydraulically actuated active suspension system is simulated with a bump input. The results show that the proposed modeling technique and the proportional integral sliding mode controller are improved the ride comfort and ride handling of the half car active suspension system.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.805-810
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• 2004

The model is verified thorough simulations and experiments. And then the developed model is applied to a half car model and automobile vibrations are analyzed. The effects of tire design parameters on the automobile vibration energy are investigated. The results from laboratory and field tests confirm the validity of the analytical model. The 17-DOF half-car model is built to analyze the automobile vibration. The characteristics of the nonlinear model for a shock absorber are applied to this model. The results from the present 17-DOF half car model incorporating the analytical tire model with tire design parameters, are compared with a 5-DOF half car model where the tire is modeled with linear springs. The results of the 17-DOF model are closed to experimental results. Using the 17-DOF model, the influences of tire design parameter are considered. According to the results of analyses, the vibrations at seat/body/wheel are predicted by simulation and experiment.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.217-217
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• 2000

A decentralized robust EA(eigensoucture assignment) controller is designed for an active suspension system of a vehicle based on a full car model with 7-degree of freedom. Using overlapping decomposition, the full car model is decentralized by two half car models. For each half car model, a robust eigenstructure assignment controller can be obtained by using optimization approach. The performance of the decentralized robust EA controller is compared with that of a conventional centralized EA controller through computer simulations.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.2 s.95
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• pp.135-147
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• 2005

As automobile technology advances, a smoother ride with less noise is desired. In order to achieve these purposes, a study on the vibration and noise produced by a moving automobile was carried out and a model for tire vibration characteristics which influence the ride performance was developed. The model was verified through simulations and experiments. The developed model was then applied to a half car model and automobile vibrations were analyzed. The effects of tire design parameters on the automobile vibration energy were investigated. The results from laboratory and field tests confirm the validity of the analytical model. The 17-DOF half-car model was built to analyze automobile vibration. The characteristics of the nonlinear model for a shock absorber were applied to this model. The results from the present 17-DOF half car model incorporating the analytical tire model with tire design parameters, were compared with the 5-DOF half car model where the tire was modeled with linear springs. The results of the 17-DOF model are close to the experimental results. Using the 17-DOF model, the influence of tire design parameter were considered. According to the analysis results, the vibrations at seat/body/wheel were predicted by simulation and experiment.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.41-50
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• 1998

In this study, to investigate a characteristics of slip ratio control of H.C.U for ABS, half car model tester were developed and a new H.C.U. was compactly designed comparing to the commercical H.C.U. for ABS. In half car model tester, variable inertia wheel has been used to load the car weights and braking forces according to the road surface conditions which were realized by pneumatic cylinder. And solenoid valves using P.W.M. (Pulse Width Modulation) method were installed in the new H.C.U The slip ratio characteristics of tire had been measured using half car model tester and the results were used in the control simulation for a new H.C.U.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.206-213
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• 2001

An overlapping decentralized robust EA(eigenstructure assignment) controller is designed for an active suspension system of a vehicle based on a full car model with 7-degree of freedom. Using overlapping decomposition, the full car model is decentralized by two half car models. For each half car model, an effective and disturbance suppressible controller can be obtained by assigning appropriately a left eigenstructure of the system. The performance of the proposed overlapping decentralized robust EA controller is compared with that of a conventional centralized EA controller through computer simulations.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.105-105
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• 2000

In this paper, an integrated control of the semi-active suspension system using a reduced full-car model is investigated. By including the reduced full-car dynamics in the control law, the semi-act ive suspension system is able to control not only the vertical acceleration but also the roll and pitch mot ions of the car body, which is not Possible with a quarter-car model or a half-car model. The damping forces for the semi-active dampers are designed to track the damping forces of the skyhook controller designed from the reduced full car dynamics. Computer simulations and experimental results using a real car are also included.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.44-50
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• 2010

Durability performance evaluation technology using Virtual Testing Method is a new concept of a vehicle design, which can reduce the automotive components design period and cost. In this paper, the fatigue life of an aluminum knuckle of a passenger car is evaluated using virtual testing method. The flexible multibody dynamic model of a front half car module is generated and solved with service loads which are measured from Belgian roads. Using a multibody dynamic analysis software, the flexible multibody dynamic simulation of a half car model is carried out and the dynamic stress profile of an aluminum knuckle is acquired. The stress profile is exported to a fatigue analysis software and durability performance of an aluminum knuckle is evaluated.

• The Journal of the Acoustical Society of Korea
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• v.32 no.4
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• pp.329-334
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• 2013

Order spectrum analysis is widely used to grasp the features of noises due to powertrain system including engine and intake/exhaust system. It is known from many previous researches that order components related to the first and second firing frequencies of engine considerably affect the noise of car interior. The purpose of this paper is to find out the difference in sound quality: Pleasantness of car interior noise according to the change of its order spectrum. For this, car interior noises of 6-cylinder and 4-cylinder engines are recorded and their order spectrum levels are modified by applying adaptive digital filters. After subjective listening test employing paired comparison method is conducted, it is investigated that the level change of half-order components is a noticeable factor to improve Pleasantness of the car interior noises whereas level decrease of firing order does not always give the positive effect on its sound quality.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.833-839
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• 2006

In this paper, roll behavior of three planar half car models are compared. The first model is a simple model whose contact point between a wheel and the ground is assumed to be fixed with a revolute joint. The second model is a modified model of the fIrst model, whose wheel tread width can vary. In this model, the instant center of a wheel with respect to the ground, which is crucial to find the roll center, is assumed to be at the contact point of a wheel and the ground. The last model uses the pole of a wheel with respect to the ground for small displacement as the instant center of a wheel with respect to the ground. Loci of the center of gravity point, the fixed and the moving centrodes which are traces of roll center position in the ground and the body frame respectively, wheel contact points, and instant centers of a wheel with respect to the ground are calculated.