• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.72-77
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• 2001

고층 빌딩의 풍하중에 의한 진동을 제어하기 위하여 MR 유체감쇠기를 이용한 반능동 제어 시스템의 설계에 대하여 연구하였다. 제안된 설계기법의 효율성을 검증하기 위하여 ASCE benchmark 구조물을 대상으로 수치 모의 해석을 수행하였다. 유전자 알고리즘을 사용하여 MR 감쇠기의 76층 빌딩 내에서의 최적위치와 용량을 결정하였으며, clipped optimal control 제어기법을 사용하여 가속도 되먹임 구조를 갖는 MR 감쇠기의 제어 알고리즘을 구성하였다, 수치 모의 해석 결과로부터 MR 감쇠기는 ATMD와 유상한 제어 성능을 가지고 있으며 매우 작은 규모의 파워 시스템만으로 운영이 가능한 효율적이고 안정적인 제어 시스템임을 확인할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.460-465
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• 2008

This paper proposes a new type of MR (magentorheological) fluid based suspension system and applies it to military vehicle for vibration control. The suspension system consists of gas spring and MR damper. The nonlinear behavior of spring characteristics is evaluated with respect to the wheel travel and damping force model due to viscosity and yield stress of MR fluid is derived. Subsequently, a military vehicle of 6WD is adopted for the integration of the MR suspension system and its nonlinear dynamic model is establishes by considering vertical, pitch and roll motion. Then, a sky-hook controller associated with semi-active actuating condition is designed to reduce the vibration. In order to demonstrate the effectiveness of the proposed MR suspension system, computer simulation is undertaken showing vibration control performance such as roll angle and pitch angle evaluated under bump and random road profiles.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.980-985
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• 2008

This paper presents vehicle road test of a semi-active suspension system equipped with continuously controllable magnetorheological (MR) dampers. As a first step, front and rear MR dampers are designed and manufactured based on the optimized damping force levels and mechanical dimensions required for a commercial middle-sized passenger vehicle. After experimentally evaluating dynamic characteristics of the MR dampers, the test vehicle is prepared for road test by integrating current suppliers, real-time data acquisition system and numerous sensors such as accelerometer and gyroscope. Subsequently, the manufactured four MR dampers (two for front parts and two for rear parts) are incorporated with the test vehicle and a skyhook control algorithm is formulated and realized in the data acquisition system. In order to emphasize practical aspect of the proposed MR suspension system, road tests are undertaken on proving grounds: bump and paved roads. The control responses are evaluated in both time and frequency domains by activating the MR dampers.

• 한국소음진동공학회논문집
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• 제19권3호
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• pp.235-242
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• 2009

This paper presents vehicle road test of a semi-active suspension system equipped with continuously controllable magnetorheological(MR) dampers. As a first step, front and rear MR dampers are designed and manufactured based on the optimized damping force levels and mechanical dimensions required for a commercial middle-sized passenger vehicle. After experimentally evaluating dynamic characteristics of the MR dampers, the test vehicle is prepared for road test by integrating current suppliers, real-time data acquisition system and numerous sensors such as accelerometer and gyroscope. Subsequently, the manufactured four MR dampers(two for front parts and two for rear parts) are incorporated with the test vehicle and a skyhook control algorithm is formulated and realized in the data acquisition system. In order to emphasize practical aspect of the proposed MR suspension system, road tests are undertaken on proving grounds: bump and paved roads. The control responses are evaluated in both time and frequency domains by activating the MR dampers.

• 한국소음진동공학회논문집
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• 제19권1호
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• pp.17-23
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• 2009

This paper proposes a new type of MR(magnetorheological) fluid based suspension system and applies it to military vehicle for vibration control. The suspension system consists of gas spring and MR damper. The nonlinear behavior of spring characteristics is evaluated with respect to the wheel travel and damping force model due to viscosity and yield stress of MR fluid is derived. Subsequently, a military vehicle of 6WD is adopted for the integration of the MR suspension system and its nonlinear dynamic model is established by considering vertical, pitch and roll motion. Then, a sky-hook controller associated with semi-active actuating condition is designed to reduce the imposed vibration. In order to demonstrate the effectiveness of the proposed MR suspension system, computer simulation is undertaken showing vibration control performance such as roll angle and pitch angle evaluated under bump and random road profiles.

• 제어로봇시스템학회논문지
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• 제8권10호
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• pp.861-866
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• 2002

A seat suspension system with a controlled MR(Magneto Rheological) fluid damper is introduced to improve the ride quality and prevent the health risk of a driver compared to fixed seats. The system is located between a seat cushion and the base, and is composed of a spring, MR fluid damper and controller. The MR fluid damper designed in valve mode is capable of producing a wide range of damping force according to applied currents. In experiments, a person was sitting on the controlled seat excited by a hydraulic system The skyhook control, continuous skyhook control and relative displacement control were applied and the continuous skyhook control improved the vibration suppression by 36.6%.

• 한국구조물진단유지관리공학회 논문집
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• 제25권1호
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• pp.41-50
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• 2021

본 연구에서는 MR Damper의 제어력을 결정하는 다양한 요인들 중, 유로폭(Gap Size)을 다르게 선정하여 그에 따른 제어력의 변화를 확인하였다. 이를 위해 Gap Size 1.0mm, 1.5mm인 MR Damper 두 대를 제작하고 인가전류와 가진조건을 정하였으며 그에 따른 동하중 실험을 수행하였다. 실험결과 최소제어력은 Gap Size 1.0mm 조건이 Gap Size 1.5mm 조건보다 3.2배 높았으며 최대제어력은 Gap Size 1.0mm 조건이 Gap Size 1.5mm 조건보다 2.3배 높았다. 또한, 인가전류에 따른 제어력의 증가폭은 Gap Size 1.0mm일 때 34N, Gap Size 1.5mm일 때 12.7N으로 나타났다. Gap Size가 커질수록 전체 제어력과 인가전류에 따른 제어력의 증가는 감소하였다. 두 개의 MR Damper의 동적범위를 확인해 본 결과 Gap Size 1.0mm일 때 평균 2.3, Gap Size 1.5mm일 때 평균 2.8인 것을 볼 때 두 MR Damper의 준능동제어장치로써 사용가능성을 확인하였다.

• 한국소음진동공학회논문집
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• 제26권2호
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• pp.165-171
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• 2016

A prosthetic knee for above-knee (AK) amputee is categorized into passive and active type. The passive prosthetic knee is generally made by elastic material. Although AK amputee can easily walk by using passive prosthetic leg, knee joint motions are not similar to ordinary persons. The active prosthetic leg can control the knee angle owing to the actuator and microprocessor. However, the active type is not cost-effective and the stability may be lost due to the malfunction of sensors. In order to resolve these disadvantages of passive and active type, a semi-active prosthetic knee which can control the knee angle is proposed in this work. The proposed semi-active one requires a less input energy but provides active type performance. In order to achieve this goal, in this work, a semi-active prosthetic knee using magneto-rheological (MR) damper for AK amputees is designed. The MR damper can support the weight of body by using less energy than actuator of active prosthetic. It can control knee angle by inducing the magnetic field at the time of stance phase. This salient characteristic is evaluated and presented in this work.