• Journal of the Korean Society for Precision Engineering
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• v.18 no.1
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• pp.56-62
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• 2001

In this paper, skyhook control of a semi-active ER(Electro-Rheological) damper 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 skyhook and Linear Quadratic Regulator(LQR) optimal control method. Computer simulation and experimental results show that the semi-active suspension with ERF damper has good performances of ride quality.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.174.1-174
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• 2001

The role of suspension system in tracked vehicles cannot be overestimated because the driving and running conditions of such vehicles are very severe. It reduces the vibration and shock which are generated by road profile in running condition. As the tracked vehicle's running speed increases, more undesired vibrations can be generated by road profile particularly in the situation of field running. Because, the excessive vibration can harm the operation ability of crewmen and stability of complex equipments, the maximum running speed is limited. In this study, to improve the performance of the tracked vehicle system, we examined the feasibility of using the active preview control for the tracked vehicle´s suspension system. First, we developed ...

• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.287-293
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• 2007

This paper proposed modelling and design method in suspension system design to analyze active suspension equipment by adopting intelligent robust control theory. Recent in the field of suspension system design it is general to adopt active control scheme for stiffness and damping, and connection with other vehicle stability control equipment is also intricate, it is required for control system scheme to design more robust, higher response and precision control equipment. It is known that active suspension system is better than passive spring-damper system in designing suspension equipment. We analyze suspension system with considering location of front-rear wheel and driving velocity, then design robust control system. Numerical example is shown for validity of intelligent control system design in active suspension system.

• Journal of Power System Engineering
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• v.6 no.2
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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.

• 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.

• Journal of KSNVE
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• v.7 no.2
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• pp.239-246
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• 1997

This paper presents an active suspension control algorithm to improve the suspension performance trade-offs between riding comfort and handling stability. In this paper, a hybrid control scheme is proposed, the idea of which is that sliding mode control is used for nonlinear hydraulic system and the skyhook control is applied to control the vehicle behavior. The parameter variations in hydraulic system are considered for the robust controller design. The performance of the proposed control method is evaluated by simulation and experiments based on a half car roll model which can reveal both heave and roll behavior.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.369-374
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• 2004

Nowadays, the more speedy and functional railway vehicles are required by customers, the more broad boundary conitions of train's running are present. At this condtion, it is difficult for the traditional concept of suspension system which has the constant characteristics dependant on the running condition to meet the advenced requirements such as high ride quality. So, the active suspension should be designed to supplied the optimized suspensnion condition actively and to perform the optimal ride quality on the irregula running condition such as on the enterance or exitance of the tunnel or on the crossing the high speed train each others. On this study, the train dynamic model, integration of active suspension system, and the control logic would be proposed, and the advanced performace of train would be shown though the simulation tests.

• Journal of KSNVE
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• v.5 no.1
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• pp.29-35
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• 1995

This paper presents the simultaneous optimal design of structure and LQG control systems for the improvement of riding comforts of active vehicle suspension systems. The performance index of riding comforts is extended to include frequency-weighted acceleration in the quadratic cost functional. Janeway human response curve with respect to acceleration is used to verify the usefulness of the presented method. The method is applied to a half model of an active vehicle suspension systems with elastic body moving on randomly profiled road. The values of stiffness of suspensions are used for the structural design variables. The conjugate gradient method is used for optimization. The simulated results of simultaneous optimization with frequency-weighted cost functional are compared with those without frequency- weighted cost functional.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1048-1053
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• 2003

This paper proposed a MR(Magneto-rheological) seat damper for a commercial vehicle. After formulating the governing equation of motion, an appropriate size of damper is designed and manufactured. Following the equation of fie d-dependent damping force characteristics, a semi-active seat suspension installed with the proposed MR-damper is constructed and its dynamic model id established, Subsequently, vibration isolation performance of the semi-active suspension system is demonstrated by incorporating with a MRAC(Model referenced adaptive control) fer the MR Seat Damper

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.28-34
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• 2011

The carbody underframe of TTX vehicle should be modified a lot for the installation of new devices such as an active suspension system between the bogie and the carbody of TTX vehicle, because the carbody underframe is one body structure consisting of a center sill welded with a carbody bolster. Modification operation of the carbody takes a lot of time and cost, because the huge sized carbody structure should be moved to a machining apparatus and machined to guarantee the manufacture accuracy of new device installation brackets. For this reason, modification operation improvement is needed to install new devices more efficiently between the bogie and the carbody. This paper introduce the development of 'bogie/carbody interface bolster' that not only supports the carbody weight but also enables new devices to be installed more efficiently between the bogie and the carbody. This development has advantage to reduce working time and cost to install new devices such as an active suspension system between the bogie and the carbody by minimizing the modification of the carbody of TTX vehicle.