• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.1
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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.

• Journal of KSNVE
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• v.9 no.1
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• pp.121-130
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• 1999

Generally, A Dynamic Absorber by using Active viscous Damping is highlighted for effective suspension system, such as improved ride comfort and handling in the market. Lately, this system based on the Sky-Hook damper theory is introduced by the name of "Active Dynamic Absorber" to us. This system has an excellent performance in contrast to Passive. Adaptive Dynamic Absorber, besides having low cost components of system, low energy consumption. light weight of system. In this viewpoint. most of car-maker will adopt this system in the near future. For this reason, we developed Dynamic Absorber by using Active viscous Damping which is equipped with continuously variable Dynamic Absorber and Control logic consisting Filter and Estimator. control apparatus of Dynamic Absorber operated by 16-bit microprocessor of high performance. variable device of viscous Damping. G-sensor so on. In this paper. several important points of development procedure for realizing this system will be described with results in which is obtained from experiment by simulation and Full car test in Proving ground. respectively.pectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.213-218
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• 2001

A magnetorheological(MR) engine mount for a passenger vehicle and its vibration control performance is experimentally evaluated. A mixed-mode model for the MR engine is derived by incorporating Herschel-Bulkely model of the MR fluid. After analyzing the field-dependent damping force, a appropriate size of the MR engine mount is manufactured. The field-dependent is displacement transmissibility of the engine mount is evaluated in the frequency domain at various excitation levels. In addition, time-dependant damping force is experimentally investigated by changing the excitation amplitude.

• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.53-61
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• 2007

A conventional passive TMD is only effective when it is tuned properly. In many practical applications, inevitable off-tuning of a TMD occurs because the mass in a building floor could change by moving furnishings, people gathering, etc. When TMDs are offtuned, TMDs their effectiveness is sharply reduced. Moreover, the off-tuned TMs can excessively amplify the vibration levels of the primary structures. This paper discusses the application of a new class of MR damper, for the reduction of floor vibrations duo to machine and human movements. The STMD introduced uses a MR damper called to semi-active damper to achieve reduction in the floor vibration. Here, the STMD and the groundhook algorithm are applied to a single degree of freedom system representative or building floors. The performance or the STMD is compared to that or the equivalent passive TMD. In addition, the effects of off-tuning due to variations in the mass of the floor system. Comparison of the results demonstrates the efficiency and robustness of STMD with respect to equivalent TMD.

• Journal of Korean Association for Spatial Structures
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• v.7 no.5
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• pp.49-56
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• 2007

Passive, active and semi-active control system are classified in floor vibration control system by providing control force. This paper discusses the application of a new class of semi-active TMD(MR-TMD), for the reduction or floor vibrations due to machine and human movements. This MR-TMD consists of passive TMD and MR damper. Here, displacement-based control methods are used to assess the performance of this STMD(MR-TMD). And, skyhook and the groundhook algorithm are applied to a single degree of freedom system representative of building floors. If the allowed operation space of tuned mass is limited in MR-TMD system, skyhook algorithm is more efficient than groundhook algorithm for floor vibration control. Hybrid control method demonstrates the efficiency of MR-TMD with respect to another methods.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.481-486
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• 2000

This paper presents vibration control performance of a passenger vehicle installed with olectro-rheological(ER) engine mounts. As a first step, a mixed-mode ER engine mount is modeled and manufactured. After verifying the controllability of the dynamic stiffness by the intensity of the electric field, ER engine mounts are incorporated with a full-car model. The governing equation of motion is then formulated by considering engine excitation force. A skyhook controller to attenuate vibration motions is designed. The controller is implemented through hardware-in-the-loop simulation and control responses are presented in the both frequency and time domains.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.2
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• pp.157-164
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• 2016

The paper studies a comparison analysis of semi-active control strategies for a Macpherson strut type suspension system consisting of MR(magneto-rheological) damper. As a first step, in order to formulate governing, a dynamic full model of a Macpherson strut is developed considering the kinematics. The nonlinear equation of motion of the strut is then linearized around the equilibrium point. A new adaptive moving sliding model controller is developed for fast response of the system. A newly proposed adaptive moving sliding mode control strategy is then compared with conventional sliding mode controller and skyhook controller. The comparison is made for two different types of road inputs; bump and random road profiles showing superior vibration control performance in time and frequency domains.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.3
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• pp.199-207
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• 2002

In this paper, a self-tuning gain-scheduled skyhook control for semi-active suspension systems is investigated. The dynamic characteristics of a continuously variable damper including electro-hydraulic pressure control valves is analyzed. A 2-d.o.f. time-varying quarter-car model that permits variations in sprung mass and suspension spring coefficient is considered. The self-tuning skyhook control algorithm proposed in this paper requires only the measurement of body acceleration. The absolute velocity of the sprung mass and the relative velocity of the suspension deflection are estimated by using integral filters. The skyhook gains are gain-scheduled in such a way that the body acceleration and the dynamic tire force are optimized. An ECU prototype is discussed. Experimental results using a 1/4-ear simulator are discussed. Also, a suspension ECU prototype targeting real implementation is provided.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.7
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• pp.614-621
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• 2001

The controllers for a full car 7-DOF model with 4 active or semi-active suspension units are designed and evaluated in this research. The control algorithms for suspension systems, such as full state feedback active, full state feedback semi-active, sky-hook active, sky-hook semi-actvie, and on-off suspension systems, are analyzed and evaluated with respect to ride comfort. The vehicle dynamic performances are expressed by response curves to a bump input, performance indices for asphalt road input, and frequency characteristic curves. Heaving, rolling, and pitching inputs are applied to the vehicle dynamic system to evaluate frequency characteristics. The simulation results show that the ride quality of the sky-hook controller approaches that the full state feedback controller more closely in semi-active suspension system than in active suspension system. For the implementation of a vehicle with sky-hook suspension control systems in this paper, 7 velocity sensors are required to measure the states.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.159-169
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• 2004

In this study, integration control of air-cell seat and semi-active suspension is proposed to minimize the road-tyre force which can cause uncomfortable feeling to rider. The proposed integration control with sliding perturbation observer is consisted of air-cell seat control which uses the force generated by air-cell and the sky-hook control. The air-cell seat itself has been modeled as a 1 degree of freedom spring-damper system. The actual characteristics of the air-cell have been analyzed through experiments. In this paper, we introduces a new robust motion control algorithm using partial state feedback for a nonlinear system with modelling uncertainties and external disturbances. The major contribution of this work is the development and design of robust observer for the state and the perturbation. The combination skyhook controller and air-cell controller using the observer improves control performance, because of the robust routine called Sliding Observer Design for Integration Control of Air-Cell Seat and Semi-active Suspension. The simulation results show a high accuracy and a good performance.