• 대한기계학회논문집A
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• 제25권2호
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• pp.206-213
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• 2001

The positioner is an essential component of the control valve which is used to control quantity of the liquid in the pipe of chemical plants. In this paper, the experimental methodology for current pneumatic positioner was developed for the investigation of the static and dynamic characteristics of the positioner. The methodology was applied to evaluate response characteristics of two different positioners, which are current model in market and newly designed model. The experimental results of these two models were compared and analyzed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.385-390
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• 1993

It is the purpose of this paper to present a dialogical tuning method of the sampling period in fuzzy control systems. Last year, the authors gave a dialogical tuning technique of fuzzy control system under the fixed sampling period in this symposium. In the case where sampling period is chosen larger, the response of the control system is unsatisfactory, and in the case where the sampling period is smaller, ineffective control actions are repeated. The appropriate sampling period is chosen through the step response of the closed loop fuzzy control process. As the tuning technique depends on the controlled plant, it is necessary to estimate the rough characteristics of it. The authors propose a method to decide th appropriate sampling period, by inspecting the characteristics of the plant.

• Journal of Biosystems Engineering
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• 제36권2호
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• pp.89-95
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• 2011

Tractor implements are mainly utilized for the tillage operation. The proposed hydraulic system control was implemented to experimental apparatus. An implement control system for tractor using proportional valve was fabricated to improve the working efficiency. Hydraulic circuit included the proportional solenoid valve and on/off solenoid valve and so on. This paper shows results of a specification and design of an implement control system for tractor using proportional valve for automation. It was conducted to evaluate response characteristics of the designed implement control system under experimental conditions of various input flow rates. The results of experiments showd that the response characteristics was sufficient to be used as the implement control system.

• 대한기계학회논문집
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• 제12권6호
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• pp.1282-1289
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• 1988

본 연구에서는 형태와 특성이 다른 솔레노이드 밸브를 사용한 위치제어 시스 템에 위에서 언급한 두가지 단속적 제어 방법을 적용하여 이들 밸브의 형태와 특성이 시스템의 응답특성에 미치는 영향을 실험적으로 규명하고 실린더 내의 압력 변화에 미 치는 영향도 조사하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.686-690
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• 2004

This paper describes the performance improvement of transient response and the modeling of small aircraft onboard generator. As the characteristics of the stator coil which are a major parameters of transient response were improved, the characteristics of transient response could be increased, therefore, the improved generator can be satisfied with large and fast load changes. Established the control model of the generator, it could be possible to do the analysis of generator performance, and improve the operational stability of the generator system using the control model.

• 제어로봇시스템학회논문지
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• 제18권12호
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• pp.1101-1105
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• 2012

This study proposes a method for improvement of PD type fuzzy controller. The method includes self tuner using gradient algorithm that is one of the optimization algorithms. The proposed controller improves simple Takagi-Sugeno type FLC (Fuzzy Logic Control) system. The simple Takagi-Sugeno type FLC system changes nonlinear characteristic to linear parameters of consequent membership function. The simple FLC system could control the system by calibrating parameter of consequent membership function that changes the system response. While the determination on parameter of the simple FLC system works well only partially, the proposed method is needed to determine parameters that work for overall response. The simple FLC system doesn't predict the response characteristics. While the simple FLC system works just like proportional part of PID, our system includes derivative part to predict the next response. The proposed controller is constructed with P part and D part FLC system that characteristic parameter on system response is changed by self tuner for effective response. Since the proposed controller doesn't include integral part, it can't eliminate steady state error. So we include a gain to eliminate the steady state error.

• 제어로봇시스템학회논문지
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• 제13권10호
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• pp.990-999
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• 2007

We deal with second order NMP(Non-Minimum Phase) systems which are difficult to control with conventional methods because of their inherent characteristics of undershoot. In such systems, reducing the undesirable undershoot phenomenon makes the response time of the systems much longer. Moreover, it is impossible to control the magnitude of undershoot in a direct way and to predict the response time. In this paper, we propose a novel two sliding mode control scheme which is capable of determining the magnitude of undershoot and thus the response time of NMP systems a priori. To do this, we introduce two sliding lines which are in charge of control in turn. One is used to stabilize the system and achieve asymptotic regulation eventually like the conventional sliding mode methods and the other to stably control the magnitude of undershoot from the beginning of control until the state meets the first sliding line. This control scheme will be proved to have an asymptotic regulation property. The computer simulation shows that the proposed control scheme is very effective and suitable for controlling the second order NMP system because it can decide the magnitude of undershoot in a direct and stable way and reduce the response time compared with the conventional ones.

• 한국정보통신학회논문지
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• 제2권3호
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• pp.295-302
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• 1998

본 논문에서는 한계계단 응답특성을 이용하여 영구자석헝 동기전동기의 속도 제어계에 대한 새로운 자동동조 PI(Proportional Integral) 제어기를 설계하였다. 과도응답 기간동안 소위 한계입력이라고 하는 계단입력을 인가하여 Pㅑ 제어기의 자동동조를 위한 정보를 얻기 위한 기법을 제안한다. 시스템 파라메터 추정과 동시에 속도제어가 온라인으로 이루어지는데, 이것은 시스템의 불확실성에도 불구하고 한계입력에 의해서 얻어진 시스템 파라메터 정보가 연속적으로 PI 제어기에 적용될 수 있다는 것이다. 제안된 자동동조 알고리즘은 단조증가 계단응답 특성을 갖는 영구 자석형 동기전동기의 속도제어에 대한 시뮬레이션과 실험결과를 통하여 그 유효함을 확인하였다.

• 한국공간구조학회논문집
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• 제6권2호
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• pp.61-68
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• 2006

본 논문에서는 패시브 진돈제어시스템을 설치한 실대물 K형 철골브레이스 골조의 실험결과를 다루었다. 패시브 진동제어시스템은 점탄성물질을 이용하여 새롭게 개발된 댐퍼를 사용하였다. 이 실험모델의 진동제어 효율성을 확인하고 철골조 브레이싱의 진동반응특성을 조사하기 위하여 일련의 실험을 행하였다. 자유진동실험결과 댐퍼를 설치시 설치하지 않은 경우와 비교하여 3배정도의 진동제어능력을 나타냈다. 점탄성물질 난류댐퍼의 효율성은 진동실험에 의하여 확인되었다.

• Journal of Advanced Marine Engineering and Technology
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• 제27권3호
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• pp.405-411
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• 2003

An electric control fuel injector of a diesel engine injection systems is very important apparatus for fuel economy and emission control. It's performance was influenced by hydraulic contro1 of valve and solenoid especially the solenoid was important factor for operation and control of injector. In this paper. we made solenoids of 4 type. which changed the shape of armature and core. and measured magnetic force according to input current, and analyzed characteristics of solenoid on the shape through the test results.