• Journal of the Earthquake Engineering Society of Korea
• /
• v.5 no.1
• /
• pp.53-61
• /
• 2001

구조물이 과동한 기진력을 받을 때에 구조물의 진동 제어를 위하여 적응형 뱅뱅 제어 알고리듬이 저자들에 의해서 제안된 바 있으며, 이 제어 알고리듬을 1자유도계의 시험 구조물에 적용하여 제어 성능을 실험적으로 확인하였다. 본 논문은 이의 연장으로서 제안된 적응형 뱅뱅 제어 알고리듬을 최상층에 유압식 농동질량 감쇠기가 설치된 다자유도계의 시험 구조물에 적용하여 이의 유용성을 확인하였다. 이를 통하여 제안된 적응형 뱅뱅 제어 알고리듬은 제어 및 전체 구조계의 안전성이 보장되는 가운데 과도항 외부의 기진력을 받는 다자유도계의 구조물의 진동을 제어함에 효과적임을 확인할 수 있었다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.12
• /
• pp.82-89
• /
• 2006

This paper describes the development results of electrohydraulic actuation system which performs the attitude and trajectory control of pitch and yaw motion using thrust vector control for high altitude launching vehicle operated in high vacuum environment (altitude higher than 300 km). As compared with electrohydraulic actuation system for low altitude launch vehicle which operated under altitude of stratosphere, the intensified development requirements, newly adopted design and manufacturing technologies, newly developed test equipments and test results are summarized in this paper. The development test and evaluation of actuation system were successfully accomplished. The developed actuation system will be installed on KSLV-I after finishing verification of interface and integration compatibility with related other systems.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.13 no.2
• /
• pp.213-220
• /
• 1989

This paper describes the application of the variable structure control(VSC) concept for the position control of an electro-hydraulic servomotor system. The basic philosopy of VSC is that the structure of the feedback control is altered as the state crosses discontinuity surfaces in the state space with the result that certain desirable properties are achieved. The switching of the control function yields total(or selective) invariance to system parameter variations and disturbances, and closed loop eigen value placement in time-varing and uncertain systems. The control scheme is derived, implemented and tested in the laboratory where analog controller have been used to control the representive servosystem. The control system schematics are given and simple results are shown for illustration. And the results of variable structure system for the electro-hydraulic servomotor were compared to that of the fixed structure system when load disturbance and system parameter variation exists.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.7
• /
• pp.947-952
• /
• 2010

Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions prescribed in ISO and SAE standards. The impulse pressure test machine needs to have a high pressure, a precise control system and a long life. It should satisfy the requirements for fabrication of the impulse tester to generate ultra high pressure in the hydraulic system. In the impulse tester, a servo-valve control system is adopted; although the control application is convenient, it is expensive owing to the cost of developing the system. The type of the control system determines the pressure wave, which affects the components that are tested. In this study, the manufacturing process and the intensifier system design related to the flow, pressure, and the increasing rate of pressure are investigated. The results indicate the ultra high pressure waves in the system.

• Journal of KSNVE
• /
• v.11 no.1
• /
• pp.96-103
• /
• 2001

Past research has repeatedly demonstrated the fact that hydraulic semiactive systems, if operated Properly, can provide levels of control authority in structural vibration control systems that are comparable to a fully active hydraulic damper. The performance of the semiactive system when used to provide vibration mitigation for a laboratory test structure is described in this paper Numerical and experimental verification of the effectiveness of the proposed bistate controller which relies on a Lyapunov approach that seeks to dissipate the energy of the system is also presented. The results based on the bistate control are compared with those of two different control strategies. The work indicates that hydraulic semiactive actuator provides a reliable, and inexpensive means of achieving structural control.

• Journal of Advanced Navigation Technology
• /
• v.13 no.5
• /
• pp.756-762
• /
• 2009

As nonlinear friction, stick-slip friction in hydraulic actuators are a problem for accuracy and repeatability. Therefore friction compensation has been approached through various control algorithms. A Adaptive discrete time sliding mode tracking controller has been applied in order to compensate the nonlinear friction characteristics in a hydraulic Actuator. Based on the diophantine equation, a new discrete time sliding function is defined and utilized for the control law which includes a friction and modeling error. Robustness is increased by using both a projection algorithm and a sliding function-based nonlinear feedforward. From the results of simulation and experiment good tracking performance is achieved.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.91-92
• /
• 2010

다이어프램은 교류주파수에 의해 전후로 이동하는 진동판으로 공기의 압력을 조절하는 장치이다. 본 논문에서는 다이어프램의 공기 유량 및 유압을 제어하기 위해서 가변주파수의 전류 제어를 통해 다이어프램의 추력을 제어하고, 이를 통해 지령치가 요구하는 유량 및 유압의 제어가 이루어지도록 하였다. 다이어프램의 토출압력은 진동판의 주파수에 의해 조절이 가능하며, 진동 및 소음은 주파수에 반비례 하게 된다. 높은 주파수에서 충분한 추력을 내기위해서 본 논문에서는 가변주파수 전류제어 방식을 사용하였으며, 그 결과를 실험으로 검증하였다.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.6 no.2
• /
• pp.183-190
• /
• 1982

이 논문에서는 유압제어장치의 응답에 대하여 관성하중, 점성하중, 쿨룸(Coulomb)마찰 및 입력 신호의 주파수가 시스템에 미치는 영향을 고찰하였고, 이에 따른 속도와 압력파형을 주로 서 술하였다. 피스톤의 드리프트(drift)와 스프링하중을 제외한 대부분의 요소가 고려되었다. 추출된 방정식은 모두 무차원화 하였으며 입력 신호를 계단함수로 할 때에는 위치 피이드백 (feedback)이 삽입되었다.

• Proceedings of the KSME Conference
• /
• 2005.11a
• /
• pp.182.2-182.2
• /
• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.10a
• /
• pp.174-178
• /
• 2001

선박내의 발전장치로는 독립된 디젤기관으로 구동되는 발전장치를 사용하는 것이 일반적이자만, 근래에는 에너지 절약과 관리, 보수의 편의를 목적으로 축발전(Shaft Generator) 시스템이 연구, 개발되고 있다. 본 연구에서는 비교적 가격이 저렴하고, 설치 공간이 적으면서고 양질의 교류전력을 얻을 수 있어 소형선박에서 사용하기에 적합한 축발전 시스템으로, 마이크로컴퓨터에 의하여 제어되는 유압구동식 축발전시스템을 제안하고자 한다.