• 한국정밀공학회지
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• 제17권1호
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• pp.34-44
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• 2000

In this paper, a modified skyhook control for the semi-active Macpherson suspension system is investigated. A new model for the semi-active type suspension, which incorporates the rotational motion of the unsprung mass, is introduced and an output feedback control law using the skyhook control method is derived. The gains in the skyhook controller are adaptively adjusted by estimating the road conditions. Because two vertical acceleration sensors, one for the sprung mass and another for the unsprung mass, are used rather than using the angle sensor for the rotational motion of the control arm, the relative velocity of the rattle space is filtered using the acceleration signals. For testing the control performance, the actual damping force has been incorporated via the hardware-in-the-loop simulations. The performances of a passive damper and a semi-active damper are compared. Simulation results are provided.

• International Journal of Automotive Technology
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• 제7권6호
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• pp.749-756
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• 2006

This paper presents a complex stochastic wheelbase preview control method of a motorcycle suspension based on hierarchical modeling method. As usual, a vehicle suspension system is controlled as a whole body. In this method, a motorcycle suspension with five Degrees of Freedom(DOF) is dealt with two local independent 2-DOF suspensions according to the hierarchical modeling method. The central dynamic equations that harmonize local relations are deduced. The vertical and pitch accelerations of the suspension center are treated as center control objects, and two local semi-active control forces can be obtained. In example, a real time Linear Quadratic Gaussian(LQG) algorithm is adopted for the front suspension and the combination of the wheelbase preview and LQG control method is designed for the rear suspension. The results of simulation show that the control strategy has less calculating time and is convenient to adopt different control strategies for front and rear suspensions. The method proposed in this paper provides a new way for the vibration control of multi-wheel vehicles.

• 한국생산제조학회지
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• 제9권5호
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• pp.127-134
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• 2000

This paper presents the development of a semi-active seat damper using MR fluids and the performance analysis of seat suspension system with a MR seat damper. An annular orifice type MR seat damper is proposed for a seat suspension of a commercial vehicle. After formulating the governing equation of motion, then an appropriate size of the seat damper is designed and manufactured. Following the evaluation of field-dependant damping force characteristics, the controllability of the damping force is experimentally demonstrated in time domain by adopting PID controller. A semi-active seat suspension with the proposed MR damper is constructed and its dynamic model is established. Subsequently, vibration control capability of the semi-active suspension system is investigated by employing the sky-hook controller.

• 한국정보통신학회논문지
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• 제10권6호
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• pp.1147-1152
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• 2006

본 논문에서는 스카이훅댐퍼 시스템의 해석 및 설계에 능동 서스펜션 강인제어 이론을 적용하여 현가장치설계에 응용 할 수 있는 이론 및 실험적 제어 장치 적용에 관한 연구를 수행하였다. 최근의 현가장치설계에서는 강성과 감쇠를 능동적으로 제어하는 기술의 적용이 일반화되고 있으며, 다른 차량안정성제어장치와의 연계성이 높아짐에 따라, 제어시스템설계에서 보다 내구성이 강하고 제어효과의 응답성이 빠르며 정도 또한 높은 제어장치의 필요성이 요구되고 있다. 본 연구는 센서의 위치 관계에 따른 능동현가시스템을 해석하여 위와 같은 빠른 응답성과 높은 정도의 제어가 가능한 제어시스템을 해석, 설계하기 위하여 강인제어시스템의 적용에 관한 고찰을 하였다. 그리고 제어대상시스템에 대한 강인제어시스템을 설계하기 위한 모델링 및 적용방법을 수식적으로 해석하였으며, 스카이훅현가장치의 제어시스템설계에 중요한 내외란성 향상을 위한 강인제어 시스템설계에 적용하는 방법에 관해 고찰하였다.

• 제어로봇시스템학회논문지
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• 제8권11호
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• pp.922-927
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• 2002

A variable structure control (VSC) based model following control system that possesses fault detection and isolation (FDI) capability as well as fault tolerance property is proposed. The nonlinear part of the proposed control law. whose magnitude is determined by sliding variables, plays the role of suppressing fault effect. Thus, approximate fault reconstruction is also possible via the analysis of sliding variables. The proposed algorithm is applied to an active suspension system of pound vehicles to verify its applicability.

• 한국자동차공학회논문집
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• 제21권2호
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• pp.26-36
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• 2013

Purpose of this study is to develop virtual components and environment for developing a controller of an Active Air Suspension System in laboratory that slough off existing development environment using real vehicle test. This paper presents an air spring modeling and analysis of air suspension system for a commercial vehicle. Preferentially, It was performed vehicle test for pneumatic system and an air spring for characteristic analysis of system. Each component of an air spring suspension system was developed through emulations and modeling of system for pressure and height sensors in the basis on test results in SILS environment. Non-linear characteristics of air spring are accounted for using the measured data. Also, pressure and volume relations for vehicle hight control is considered. After performance verification of virtual model was performed, we developed virtual environment based on HILS for an Active Air Suspension System. We studied estimation and verification technology for control algorithm that developed.

• 한국소음진동공학회논문집
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• 제26권1호
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• pp.82-88
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• 2016

This paper proposes a new type of semi-active direct-drive valve(DDV) car suspension system using piezoelectric actuator associated with displacement amplifier. As a first step, controllable piezoelectric DDV damper is designed and governing equation of a quarter-vehicle suspension system consisting of sprung mass, spring, tire and the piezostack DDV damper is constructed. After deriving the equations of the motion, in order to control spool displacement and damping force the skyhook controller is designed and applied. The performance evaluation of the proposed semi-active suspension system is conducted with different displacement of spool. Then, the ride comfort analysis is undertaken in time domain with bump road profile.

• 한국자동차공학회논문집
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• 제9권6호
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• pp.186-194
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• 2001

To meet the challenge of testing increasingly complex automotive control systems, the real-time hardware-in-the-loop(HIL) simulation technology has been developed. In this paper, a strategy for evaluation of semiactive suspension systems using real-time HIL simulation is presented. A multibody vehicle model is adopted to simulate vehicle dynamic motions accurately. Accuracy of the vehicle simulation results is compared to that of the real vehicle field test and proven to be very accurate. The controller and stepping motor to adjust semi-active damper stage are equipped as external hardwares and connected to the real-time computer which has vehicle dynamic model. Open and closed loop test methods are used to evaluate a controlled suspension system and the system's operations are verified it is found that the proposed evaluation methods can be used well for the verification of semi-active suspension systems.

• 한국소음진동공학회논문집
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• 제14권1호
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• pp.17-23
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• 2004

The semi-active suspension system is getting widely adopted in passenger vehicles for its ability to improve ride comfort over the passive suspension system while not degrading driving safety. A key to the success is to develop practical controllers that yield performance enhancement over the passive damper under various driving conditions. To this end, several control strategies have been studied and evaluated in this research in consideration of practical aspects such as nonlinearity and dynamics of the damper. From simulation results. it has been observed that, with the proposed control schemes, ride comfort can be significantly upgraded while suppressing degradation of driving safety.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1219-1224
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• 2007

This is Presents experimental results of a force tracking controller for a quarter-car suspension system. The active suspension system was decomposed into two loops. At the main loop, the desired force signal is calculate by using a standard LQ design process. The Time Delay Control(TDC) design technique is then used to design the force controller such that the desired force signal is achieved in a robust manner when actuator or other plant uncertainties are present. The ADAMS controls module was used to realize the joint simulation of ADAMS and MATLAB, of which the results showed that the TDC strategy is reasonable and feasible.