• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.104-111
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• 1999

A semi-active suspension system for a vehicle using an Electrorheological Fluid damper has been studied. Apparent viscosity of ERF(Electrorheological Fluid) can be changed rapidly by applying electric field. The damping force of ER damper can be selectively controlled by employing electric field to the ER fluid domain. This paper deals with a two-degree-of-freedom suspension using the ER damper for a quarter car model. An intelligent control method using fuzzy control with genetic algorithm has been employed to control the damping force of the ER damper. The GA designs the optimal structure and performance of Fuzzy Net Controller having hybrid structure. The designed fuzzy net controller has been compared with the skyhook type controller for a quarter car model. The computer simulation results show that the semi-active suspension with ER damper has a good performance in the sense of ride quality with less vibration for ground vehicle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.3
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• pp.5-10
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• 2006

The objective of this paper is to investigate the Intelligence control characteristics of a digital damper. This paper deals with a two-degree-of-freedom suspension using the damper with ER fluid for a quarter vehicle system. The control law for semi-active suspensions modeled in this study is developed using passive and ANFIS control method. Computer simulation results show that the semi-active suspension with ER damper has good performances of ride quality.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.71-76
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• 2010

This paper presents the feasibility for improving the ride quality of railway vehicle equipped with semi-active suspension system using magnetorheological(MR) fluid damper. In order to achieve this goal, a fifteen degree of freedom of railway vehicle model, which includes a car body, bogie frame and wheel-set is proposed to represent lateral, yaw and roll motions. The MR damper system is incorporated with the governing equation of motion of the railway vehicle which includes secondary suspension. To illustrate the effectiveness of the controlled MR dampers on railway vehicle secondary suspension system, the sky-hook control law using the velocity feedback is adopted. Computer simulation for performance evaluation is performed using Matlab. Various control performances are demonstrated under external excitation which is the creep force between wheel and rail.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.2
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• pp.83-94
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• 1994

Performance test result on prototype car equipped with low-band type active suspension system is reported. Control theory is explained first. Simulation for feasibility and parameter tuning, control module test using hydraulic exciter and test run, and performance evaluation of the test car on test track are reported successively. Emphasis was put on modification of control theory which caused many unexpected problems in actual implementation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.713-719
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• 2012

This paper is concerned with the dynamic modeling for the hardware-in-the-loop simulation of lateral vibrations of a railway vehicle. The resulting dynamic model is a nine degree-of-freedom model which can describe the lateral, roll and yaw motions of the car body and two bogies. It is assumed that the external disturbances come from wheel motions. In order to test the efficacy of the model, the linear quadratic regulator and the sky-hook control algorithm were designed and applied to the model. The simulation results show that both control algorithms are effective in suppressing the vibrations of railway vehicles.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.7
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• pp.634-641
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• 2012

This paper is concerned with the dynamic modeling for the hardware-in-the-loop simulation of lateral vibrations of a railway vehicle. The resulting dynamic model is a nine degree-of-freedom model which can describe the lateral, roll and yaw motions of the car body and two bogies. It is assumed that the external disturbances come from wheel motions. In order to test the efficacy of the model, the linear quadratic regulator and the sky-hook control algorithm were designed and applied to the model. The simulation results show that both control algorithms are effective in suppressing the vibrations of railway vehicles.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.4
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• pp.582-589
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• 1996

In this paper, an adaptive control problem of a hydraulic actuator for vehicle active suspension controller is divided into two parts: the inner loop controller and the outer loop controller. Inner loop controller, which is a nonlinear adaptive controller, is designed to control the force generated by the nonlinear hydraulic actuator acting under the effects of Coulomb friction. For simplicity of designing a nonlinear controller, the spool valve dynamics of a hydraulic actuator is reduced using a singular perturbation technique. The estimation error signal used to an indirect parameter adaptation is calculated without a regressor filtering. The absolute velocity of a sprung mass will be damped down by its negatively proportional term(sky-hook damper) adopted as an outer loop controller. Simulation results are presented to show the importance of controlling the actuator force and the validity of the proposed adaptive controller. (author). refs., figs. tab.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.469-475
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• 2006

In this paper, an optimal suspension system with preview of the road input is synthesized for a half tracked vehicle. The main goal of this research is to improve the ride comfort characteristics of a fast moving tracked vehicle in order to maintain the driver's driving capability. Several different kinds of preview control algorithms are evaluated with active or semi-active suspension systems. The road information estimated from the motion of the 1st road-wheel is adequate to make the best use of the preview control algorithm for tracked vehicles. The ride-comfort characteristics of the tracked vehicle are more dependent on pitching angular acceleration than heaving acceleration. The pitching motion is reduced by the suspension system with hard outer suspensions and soft inner suspensions. Simulation results show that the performance of sky-hook algorithms for ride comfort nearly follow that of full state feedback algorithms.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.2
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• pp.73-82
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• 1994

Low-band type active suspension system is implemented on a passenger car. Level. roll, pitch and bouncing motion of body are controlled by a digital controller. Sky-hook damper is applied to control bouncing motion. This paper describes overall construction of the system, design of hydraulic system, sensor system, controller, and control scheme. Performance of prototype car has been evaluated on a test track and reported in the second paper.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.121-123
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• 2008

The suspension systems currently in use can be classified as passive, semi-active and active. The passive suspension systems are the most commonly used due their low price and high reliability. However, this system cannot assure the desired performance form a modern suspension system. An important improvement of suspension performance is achieved by the active systems. This paper treats active damper system and applying DC-Motor. In this system, all the energy for active control is supplied from the damper, which regenerates energy. And simulations by sky-hook control.