• 한국항공우주학회지
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• 제37권5호
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• pp.450-456
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• 2009

수동형 진동제어 방식과 같이 시스템이 안정되며, 수동형에 비해 높은 제진 효과가 기대되는 반능동 진동제어 방식은 시스템의 안정화가 요구되는 우주구조물의 제진방법에 유효한 진동제어 방식중 하나이다. 본 논문에서는 유연우주트러스구조물의 진동제어를 위해 고안된 반능동 댐퍼내 작동유체의 질량을 모델링에 고려했을 경우의 제진특성을 분석하였고 댐퍼내 작동유체의 점성이 부족감쇠를 유지 할 경우, 작동유체 질량 적용에 따른 반능동 댐퍼의 제진효과를 확인하였으며 이를 토대로 반능동 댐퍼의 성능향상을 위한 설계방법을 제시하였다.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.77-83
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• 2008

Semi-active cabin air suspension system improves driver's comfort by controlling the damping characteristics in accordance with driving situation. For the driver's comfort evaluation, test procedure has the two methodologies which are filed test and lab test. A field test method has a drawback. It requires a lot of time and money on repetitive test, due to the sensitivity of field test. On the other hand, the test with six axes simulation table at laboratory can obtain the repeatability of test, better than the field test method. In this paper, the procedures of ride performance test and control logic tuning with the table are presented. Drive files of the table can be represented with the almost same input condition as field test data. According to the result from the comparative test using six axes simulation table between passive and semi-active system by making ECU logic tuning, the RMS acceleration of semi-active cabin air suspension system was reduced by 29.6% compared with passive system.

• 한국지진공학회논문집
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• 제10권1호
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• pp.51-62
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• 2006

다양한 원인에 의해서 발생하는 구조물의 동적응답을 감소시키기 위하여 현재까지 여러 가지 형태의 동조질량감쇠기(Tuned Mass Damper; TMD)가 개발되었고 이에 대한 많은 연구가 수행되어 왔다. 본 연구에서는 구조물의 응답에 따라서 실시간으로 TMD의 감쇠를 변화시킬 수 있는 준능동 TMD(Semi-active TMD; STMD)의 제어성능을 다양한 형태의 하중을 적용하여 해석적으로 검토하였다. STMD를 구성하는 준능동 감쇠기의 감쇠력을 조절하기 위하여 skyhook 제어알고리즘을 이용하였다. 조화하중 및 임의의 동적하중을 직접가력하중과 지반진동하중 형태로 단자유도 구조물에 가하여 STMD와 일반적인 TMD의 제어성능을 비교하였다. 또한, 주구조물의 질량의 변화에 따른 TMD 및 STMD의 제어성능의 견실성을 비교하였다. 그리고, 가변감쇠장지 뿐만 아니라 MR 감쇠기를 사용한 STMD의 제어성능도 평가하여 새로운 진동제어장치로서의 활용가능성을 검토하였다. 수치해석을 수행한 결과 STMD는 TMD에 비하여 조화하중 및 임의의 동적하중에 대해서 매우 뛰어난 제어성능을 보이는 것을 확인할 수 있었다.

• 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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.510-518
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• 2008

This paper presents recent development of (semi)-active steering bogies for railway vehicles and introduce the state-of-art of related technologies. Steering bogies have been studied in various researchers since they can offer high ride quality for passengers and reduce the maintenance costs of wheel and rail wear. Especially, they are considered to be a fundamental solution to dramatically reduce the squeal noise on tight curves. However, passive steering bogies such as self-steering bogies and forced steering bogies have shown their limits to cope with the various running conditions. Therefore, (Semi)-active steering bogies have been studied to overcome the drawbacks of the passive steering bogies. As a result, an active steering bogie, so called mechatronic bogie, is developed successfully in Europe and it has shown remarkable performance in test line.

• Smart Structures and Systems
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• 제11권2호
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• pp.163-183
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• 2013

Control systems have been greatly studied in recent years and can be classified as: passive, active, semi-active or hybrid systems. Most forms of control systems have been applied in a centralized manner where all the information is sent to a central node where control the algorithm is then calculated. One of the possible problems of centralized control is the difficulty to scale its application. In this paper, a completely decentralized control algorithm is analytically implemented. The algorithm considers that each of the control systems makes the best decision based solely on the information collected at its location. Semi-active control is used in preference to active control because it has minimal energy consumption, little to no possibility of destabilization, a reduction in the possibility of data saturation, and a reduction in the response time in comparison to centralized control.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.190-198
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• 1999

Continuously controlled semi-active suspension system may improve ride and handling properties. Here, as a mechanism to control the fluid flow solenoid valve mechanism is introduced and added to the basic passive damper to create damping forces of the shock absorbers. The system may produce continuously controlled damping forces in both solenoid valve only and combination with passive shock absorber including fluid flow is studied, and then the combined model is added to the full vehicle model to evaluate its ride and handling performance. Finally, the simulation results are compared to the vehicle models having similar suspension system.

• 한국대기환경학회지
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• 제21권5호
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• pp.481-494
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• 2005

The monitoring of persistent organic pollutants (POPs) in the atmosphere is a basis for the study of the fate of POPs in multimedia environments. Recently, passive air samplers (PASs) for POPs have been developed. In this paper, we deal with the principle, properties, and applications of the PAS. The principle of PAS, which has no pump, is physical sorption of semi-volatile organic chemicals on various sorbent materials. The PAS is much smaller than a high-volume air sampler and does not need electricity. These properties of the PAS make it possible to conduct various-scaled environmental monitoring all over the world including the Arctic and Antarctic, but the major disadvantage of PAS is its long sampling periods up to 2 years. To date, four kinds of PAS have been developed: polyurethane foam (PUF), polymer-coated glass (POG), semi-permeable membrane devices (SPMDs), and XAD resin-based PAS. Among them, SPMDs have been commercialized and are most widely used now. Meanwhile, the POPs emitted from China have a large potential to influence the levels and fates of POPs in Korea. Since characteristics of PAS are quite useful to monitor long-range transport of POPs, the use of PAS is highly recommended.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.568-573
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• 2003

This paper proposed to recognize and tracking the ID and location when a person and objects moved from indoor using RFID a type of passive tag. An antenna was installed in both sides of a door due to the limitation of a recognition distance. And frequency bandwidth was used to the 134.2kHz bandwidth to pass and bend several obstacles. Because a type of passive tag is a semi -permanent and miniaturization, it has applied to this paper.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.59-63
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• 2011

Friction damping is one of the attractive vibration control technique for space structures due to its simplicity and large damping capacity. However, passive approaches for friction damping have a limitation because energy is no longer dissipated at sticking. In order to overcome this problem, semi-active control methods to adjust normal force at frictional interface have been studied in previous researches. In this paper, two semi-active friction control method is compared by simulating SDOF model of truss structure. The first approach is on-off control to maximize rate of energy dissipation, whereas the second concept is variable friction force control to minimize amplitude ratio for each half period. The maximum friction force, control variable in on-off control method, is obtained to minimize 1% settling time, and is different from optimal friction force in passive control. Simulation results show that performance of on-off control is better than that of variable friction force control in terms of settling time and controlled friction force.