• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.937-941
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• 2004

Since semi-active suspension systems of automobile, of which suspension damper are controlled actively, exhibit high performance with light system weight, low cost and low energy consumption. From this view point, semi-active suspension systems are greatly expected to be in the mainstream of future controlled suspension systems. In this Paper, mathematical modeling and dynamic characteristics analysis of a reverse continuously variable damper and valve used for semi-active suspension systems are investigated. The mathematical model of piston with valve are proposed by IMAGINE/AMESim in the paper. To verify the mathematical model developed, the dynamic characteristics are simulated by IMAGINE/AMESim and are compared with experimental results. It was confirmed that the developed models represent well the actual system and can be used for control system design.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.57-65
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• 2011

In this paper, a hydropneumatic modeling and dynamic analysis of a heavy truck semi-active cabin air suspension system is presented. Semi-active cabin air suspension system improves driver's ride comfort by controlling the damping characteristics in accordance with driving situation. So it can reduce vibration between truck frame and cabin. Semi-active cabin air suspension system is consist of air spring, leveling valve and CDC shock absorber, and full cabin system are mathematically modelled using AMESim software. Simulation results of components and full cabin system are compared with experimental data of components and test results of a cabin using 6 axis simulation table. It is found that the simulation results are in good agreements with test results, and the hydropneumatic model can be used well to predict dynamic characterics of heavy truck semi-active cabin air suspension system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.248-253
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• 2013

The maximum speed is one of the most important performance in high speed railway vehicle. The higher the train speed is, the worse the ride comfort is, In order to solve this problem, a semi-active or active suspension can be applied to high speed railway vehicle. The variable damper with hydraulic solenoid valve is used in the semi-active suspension. But the variable damper with hydraulic solenoid valve requires tank for supplying fluid. The MR(Magneto Rheological) damper can be considered instead of hydraulic variable damper which needs additional device, i.e. reserver tank for fluid. In the case of active suspension, hydraulic actuator or electro-mechanical one is used to suppress the carbody vibration in railway vehicle. In this study the MR damper and electro-mechanical actuator was considered in secondary suspension system of high speed railway vehicle. The dynamic analysis was performed by using 10-DOF dynamic equations of railway vehicle. The performance of the semi-active suspension and active suspension system were reviewed by using MATLAB/Simulink S/W. The vibration suppression effect of semi-active and active suspension system were investigated experimentally by using 1/5-scaled railway vehicle model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.144-147
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• 2000

In this paper, ANFIS intelligence control of a semi-active suspension system is investigated. The strength of the ER damper is controlled by a high voltage power supply. This paper deals with a two-degree-of-freedom suspension using the damper with ERF for a quarter vehicle system. The control law for semi-active suspensions modeled in this study is developed using passive and ANFlS control method. Computer simulation results show that the semi-active suspension with ERF damper has good performances of ride quality

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.278-281
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• 2003

The focus of this research is to realize the function which is equivalent to the active suspension system, with controlling semi-active suspension through the attenuation of power variable damper in lower cost and smaller energy. Actually some semi-active suspension systems have been adopted, but they are not sufficient in performance. The authors intended to develop more effective and practical system and applied the optimal control technique. The results of experiments with practical suspension system showed a degree of improvement of comfortableness.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.139-147
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• 2001

2 DOF half-car model with 6 semi-active suspension units is utilized to evaluate the tracked vehicle dynamic performance simulated by several suspension control algorithms. The target of this research is to improve the ride comfort to maintain operator's handling capability when the tracked vehicle travels fast on the rough road. The control algorithms for suspension systems, such as full state feedback active, full state feedback semi-active, sky-hook active, sky-hook semi-active, and on-off systems, are evaluated and analyzed in view point of ride comfort. The dynamic performances of vehicle are expressed and evaluated by vibratory characteristic evaluation curves, performance indices and frequency characteristic curves. The simulation results show that the performances of sky-hook algorithms for ride comfort nearly follow those of full state feedback algorithms and on-off algorithm is recommendatory when the vehicle runs relatively fast.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.1
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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.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.135-143
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• 2003

In this study, a real-time simulation model was developed for tracked vehicles with in-arm type semi-active hydro-pneumatic suspension unit using MATLAB S-functions. Since the vehicle model uses relative coordinates and massless link elements, the developed model has an enhanced analytic time performance. Through the comparison of simulation results with multi-body software(DADS), the vehicle model is verified. A controller using on-off skyhook control algorithm is designed with the pilot-centre]led proportional valve based on conventional damper characteristics. Exploiting the developed tracked vehicle model with other subsystem model such as a controller model, a suspension unit model, and a test road model, computer simulations are carried out. Control simulation results with the developed tracked vehicle model show that the semi-active suspension control system has a better performance than the conventional suspension system.

• Journal of Biosystems Engineering
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• v.37 no.3
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• pp.148-154
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• 2012

Purpose: In order to improve road-friendliness of heavy vehicles, a fuzzy hybrid control strategy consisting of a hybrid control strategy and a fuzzy logic control module is proposed. The performance of the proposed strategy should be effectively evaluated using a hardware-in-the-loop (HIL) simulation model of a semi-active suspension system based on the fuzzy hybrid control strategy prior to real vehicle implementations. Methods: A hardware-in-the-loop (HIL) simulation system was synthesized by utilizing a self-developed electronic control unit (ECU), a PCI-1711 multi-functional data acquisition board as well as the previously developed quarter-car simulation model. Road-friendliness of a semi-active suspension system controlled by the proposed control strategy was simulated via the HIL system using Dynamic Load Coefficient (DLC) and Dynamic Load Stress Factor (DLSF) criteria. Results: Compared to a passive suspension, a semi-active suspension system based on the fuzzy hybrid control strategy reduced the DLC and DLSF values. Conclusions: The proposed control strategy of semi-active suspension systems can be employed to improve road-friendliness of road vehicles.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.783-788
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• 1990

Computer simulation is carried out for passive, active, and semi-active suspension system. Each RMS and frequency response to road profile input is calculated for comparison and evaluation of the performance. The vibration analysis and active control of the quarter model of a vehicle suspension is studied in order to evaluate the alternative control laws. This paper derives an optimal closed-loop feedback law for the semi-active suspension that justifies the clipped optimal approach.