• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2263-2265
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• 2004

발전소 증기터빈 밸브제어의 핵심을 이루고 있는 서보밸브 제어특성을 파악하고, 조속기 개조에 필요한 제어루프 구성방법 및 각종 제어상수를 시험을 통해 미리 파악하여 교체 적응 시에 발생될 문제점을 해결하고자 시험한 내용을 서술하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.4
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• pp.475-481
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• 2013

The control system of a direct drive servo valve is a nonlinear system, and the flow force effect on the spool motion is significant and dependent on the load pressure. To satisfy the control system design requirements, the optimal parameters of the lead-lag controller and the derivative feedback controller are searched for using a genetic algorithm and a complex constrained direct search type method. The obtained controller parameters successfully perform their role to satisfy the control system design requirements.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.510-515
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• 1993

본 연구에서는 저속에서도 시스템의 자세 제어가 용이하게 하기 위하여 추진기 뒤에 제어판이 위치하도록 설계하였으며, 일반 서보 시스템과는 달리 무게와 공간 제약이 크고, 제어판 운동에 따른 외란 등록성의 변화가 심하므로 push-pull 형태의 소형, 고출력 편로드 복동 복수 실린더의 작동기를 설계하였다. 또한 일반적으로 서보밸브와 작동기는 일체형으로 설계되나 본 시스템의 공간상 심한 제약으로 인하여 서보밸브와 작동기를 분리하는 방법으로 구조설계를 하고 그 사이 유로는 매니폴드식으로 하여 동력전달을 하였다. 설계된 구동장치를 실제 정밀제작하여 실험을 수행하였으며, 시뮬레이션 결과와 실험에 의하여 얻어진 결과를 비교 분석하여 설계의 타당성 및 시스템의 성능을 검증하였다. 고속 수중운동체에 대하여 저속에서 자세제어를 용이하게 하고, 제한된 좁은 설치공간의 문제점을 해결하기 위하여 1) 추진기 후미에 독립된 4개의 상, 하, 좌, 우 제어판 설치 2) 서보밸브는 몸체에, 작동기는 Tail Tube에 분리 작동 설계 3) 소형의 편로드 복동 복수 실린더로 설계 구성된 유압식 구동장치는 시뮬레이션과 실험 결과를 통하여 시스템의 타당성을 입증하였다. 그러므로, 개발한 구동장치는 저속에서도 큰 제어력으로 자세 제어가 용이하기 때문에 얕은 수심에서 발사시 예상되는 위험 요소를 상다ㅇ 개선 시키므로써 운용범위의 다양화를 가져 올것으로 기대된다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.5
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• pp.475-482
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• 2014

The precision hydraulic valve is widely used in various industrial field like aircraft, automobile, and general machinery. Servo actuator is the most important device for driving the precise hydraulic valve. The reliable operation of servo actuator effects on the overall hydraulic system. The performance of servo actuator relies on frequency response and step response according to arbitrary input signal. In this paper, we performed the analysis for the components of servo actuator to satisfy the reliable operation and response characteristics through the reliability analysis, and also induced the design parameters to realize the reliable operation and fast response characteristics of servo actuator for hydraulic valve operation through the empirical knowledge of experts and electromagnetic theories. We suggested the design equations to determine the values of design parameters of servo actuator as like bobbin size, length of yoke and plunger and turn number of coil, and verified the achieved design values through FEM analysis and performance tests using some prototypes of servo actuators adapted in hydraulic valve.

• Transactions of The Korea Fluid Power Systems Society
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• v.5 no.4
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• pp.10-16
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• 2008

In this paper, the authors benchmark a servo valve model for the fuel supply system of Auxiliary Power Unit (APU) in the KHP helicopter. This valve is directly driven with a torque motor, and the size of small gap controlled by a flapper can make change of flow rate under given pressure drop between inlet and outlet. CFD analyses using a commercial code, ANSYS-CFX 10 are performed for the series of three-dimensional models at various openness conditions. The computational results on simplified models show that CFD can play a fine roll in the design of flow path as well as in the estimation of flow force due to its precision and good repeatability. Consequently, the CFD analysis helps valve designers to understand its flow characteristics from the basis of physical fundamentals.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.710-714
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• 2005

A dynamical analysis and PID control of a compressed gas expulsion system is performed. The purpose of this study is to develop a compressed gas discharging system and to verify the validity of the system. The electro-hydraulic servo valve is modeled as a 3th order transfer function to calculate flow force affecting expulsion valve is significantly considered. The friction force in the expulsion valve is considered as a nonliner model of stribeck effect. The dynamic characteristics of this system is examined by the computer simulation. The position control of the expulsion valve is performed by PID controller.

• Journal of Drive and Control
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• v.9 no.4
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• pp.32-41
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• 2012

Most diagnosis methods for servo valves requires installing spool displacement sensor or flow sensor as well as pressure sensor. The measurement of flow is hard to implement and many kinds of servovalves or proportional direction valves do not have a built-in spool displacement sensor. In this study, static performances of servovalve or proportional-direction-valve are studied theoretically and a diagnosis technique, which uses only load pressure and input current signal, is assessed. An experimental setup was made based upon a personal computer and the LabVIEW graphical language. A series of diagnosis tests were performed and the analysis results showed it possible to measure the pressure gain, hysteresis and null bias in a relatively simple methodology.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.9
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• pp.76-81
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• 2006

This paper deals with a fuel metering unit (referred to as FMU) for air breathing engine. The proposed FMU consists of a constant pressure drop valve and a metering valve, both of which are controlled by servovalve. Linear analysis derived from a nonlinear mathematical model of FMU is carried out to find major parameters on the system performance. Numerical results using established model of FMU were in good agreement with the experimental results. It is also shown that the system stability is improved by reducing the constant pressure drop at metering valve and applying the triangular orifice to constant-pressure-drop valve through the simulation and experiments.

• ICROS
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• v.5 no.1
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• pp.35-40
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• 1999

• 기계와재료
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• v.11 no.2 s.40
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• pp.22-29
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• 1999