• 문화기술의 융합
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• 제9권1호
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• pp.619-625
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• 2023

본 논문에서는 다수의 체압 센서가 내장된 의료용 침대의 원격 케어에 관해 기술한다. 낙상은 환자의 안전을 심각하게 위협하고 건강을 해치는 요인중의 하나이다. 본 연구에서는 이를 극복하기 위해 새로운 침대가 개발하였다. 침대 시스템은 동작이 가능한 건반, 건반의 동작을 관리하는 건반 제어기, 체압을 측정하는 센서, 센서의 값을 송수신하는 센서 제어기, 이를 확인하여 알고리즘에 따라 자동 혹은 수동으로 동작하게 하는 메인 제어기, 이 모든 정보를 총괄하는 서버로 이루어져 있다. 침대 시스템은 센서를 통해 환자의 위치를 확인하여 환자가 낙상의 위험이 있다고 판단하게 되면 메인 제어기를 통해 무선으로 서버에 경고를 보내 간호인 혹은 간호사가 환자의 위험한 상태를 인지할 수 있도록 한다. 서버는 유무선 단말에서 송신된 상태 데이터를 전송받아 침대 시스템이 정상적으로 동작하고 있는지 모니터링할 수 있다. 건반의 제어기는 건반형 메커니즘을 구동하고 체압 센서가 연결된 욕창 예방 제어를 자동으로 행하여 환자의 압력이 가해지는 부위를 물리적으로 분리해 욕창을 예방한다. 메인 제어기는 환자의 침상 존재를 확인하여 서버에 전송한다. 결론적으로 제안된 시스템은 사용자의 상태를 스마트 모니터링하고 원격 케어를 행할 수 있게 된다.

• 한국항공우주학회지
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• 제38권10호
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• pp.992-997
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• 2010

과학기술위성3호(STSAT-3)용 홀추력시스템(HPS)의 추력제어모듈(PCM)은 압력정밀도 5%이하와 유량정밀도 3%이하를 목표로 한다. 압력제어기는 비례유량제어밸브(PFCV)와 저압압력센서를 사용하여 목표압력을 제어하도록 하고, 유량제어기는 PFCV와 홀추력기의 에노우드(anode) 전류를 이용하여 유량을 조절한다. 제어형태로는 비례,적분(PI) 제어기를 선택하고, PI 이득은 Matlab 시뮬레이션을 통하여 정한다. 시험결과 압력정밀도 <${\pm}$5%와 유량정밀도 <${\pm}$1.87%를 얻었다. 본 논문은 홀추력 제어모듈의 설계, 구현, 그리고 성능시험 결과를 기술한다.

• 한국공작기계학회논문집
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• 제14권1호
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• pp.95-100
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• 2005

Making the best use of the features of the electro-rheological(ER) valve, a two-port pressure control valve using ER fluids is proposed and manufactured. The ER-Valve characteristics are evaluated by changing the intensity of the electric field and the number of electrode. In addition, the performance of the plate type ER-Valve is investigated by change the particle concentration of the ER fluid. As only with electrical signal change to the ER-Valve in which ER fluid flowing, ER fluid flow is controlled, so development of simple ER-Valves have been tried. The ER-Valves and pressure drop check method are considered to be applied to the fluid power control system. Using the minかnぉd pressure control valve, a one-link manipulator with FHA in robot system is driven. As a result, it is experimentally confirmed that the pressure control valve using ER fluids is applicable to use in driving actuator. If it applies characteristics of the ER fluids, it will be able to apply in the control system fir the ER Valve which occurs from industrial controller(PLC).

• 제어로봇시스템학회논문지
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• 제6권3호
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• pp.329-337
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• 2000

This study describes a pressure tracking control of hydroforming process which is used for precision forming of sheet metals. The hydroforming operation is performed in the high-pressure chamber strictly controlled by pressure control valve and by the upward motion of a punch moving at a constant speed, The pressure tracking control is very difficult to design and often does not guarantee satisfactory performances be-cause of the punch motion and the nonlinearities and uncertainties of the hydraulic components. To account for these nonlinearities and uncertainties of the process and iterative learning controller is proposed using Cerebellar Model Arithmetic Computer (CMAC). The experimental results show that the proposed learning control is superior to any fixed gain controller in the sense that it enables the system to do the same work more effectively as the number of operation increases. In addition reardless of the uncertainties and nonlinearities of the form-ing process dynamics it can be effectively applied with little a priori knowledge abuot the process.

• 한국정밀공학회지
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• 제25권12호
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• pp.75-81
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• 2008

A robust controller is proposed for regulating effectively the pressure of control cylinder of swash plate type variable displacement axial piston pump. In order to design a precise and robust pressure control system, a mathematical model for swash plate control system is identified by the signal compression method. Based on the identified mathematical model, an $H_{\infty}$ robust swash plate controller is designed which is robust to the variation of the load pressure. The precise and robust swash plate control characteristics are verified by experiments.

• 센서학회지
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• 제19권5호
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• pp.375-384
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• 2010

In this paper, we proposed a new shaft distortion correction system having an adaptive PID controller using displacement sensors, which is adaptively reflecting variations of shaft strength owing to irregular heat treatment during an annealing process and sensitivity to the seasonal temperature changes. Generally, the shafts are annealed by heat treatment in order to enlarge the strength of the shaft, which causes an distortion of a shaft such as irregular bending of the shaft. In order to correct such a distortion of the shaft, a mechanical pressure is properly impacted to the distorted shaft. However, the strength of every shaft is different from each other owing to irregular annealing and seasonal temperature changes. Especially, the strength of a thin shaft such as a car transmission shaft is much more sensitive than that of a thick shaft. Therefore, it is very important for considering the strength of each shaft during correction of the car transmission shaft distortion in order to generate proper mechanical pressure. The conventional PID controller for the shaft distortion correction system does not consider each different strength of each shaft, which causes low productivity. Therefore, we proposed a new PID controller considering variations of shaft strength caused by seasonal temperature changes as well as irregular heat treatment and different cooling time. Three displacement sensors are used to measure a degree of distortion of the shaft at three different location. The proposed PID controller generates adaptively different coefficients according to different strength of each shaft using appropriately obtained pressure times from long-term experiments. Consequently, the proposed shaft distortion correction system increases the productivity about 30 % more than the conventional correction system in the real factory.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.302-307
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• 1989

A pressure tracking control of hydroforming process is considered in this paper. To account for nonlinearities and uncertainties of the process, an iterative learning control scheme is proposed using Cerebellar Model Arithmatic Computer (CMAC). The experimental result shows that the proposed learning control is superior to any fixed gain controller in the sense that it enables the system to do the same work more effectively as the number of operation increases.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.665-666
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• 2009

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 추계학술논문발표회 논문집
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• pp.7-10
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• 2008

In our study, Monitoring RF System in real-time on leakage of gas cylinder is developed. The system is consisted of Pressure Transmitting part, Main Controller and Operating program. The pressure data of gas cylinder are transmitted to the modem of main controller part by RF module of Pressure Transmitting part and the data received through the modem are recorded in real-time and showed the situation of gas cylinder on the PC monitor. Through the test on the case of the artificial pressure-reduction, the detecting performance. of the developed system is conformed.

• 한국정밀공학회지
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• 제22권7호
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• pp.155-163
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• 2005

Pressure heating rollers with temperature control were mounted to a flat cable laminating machine (FCLM). Pressure heating rollers should be heated up to the setting temperature $(175^{\circ}C)$ and kept on to producing good quality flexible flat cables (FFC). Existing Pressure heating rollers took more than 70minutes to the setting temperature and did not keep on the setting temperature in production. Temperature controller, electric power controller, material and diameter of rollers and heat capacities were changed to improve the temperature control of the pressure heat rollers for better production of the FFC. Thus, the reaching time to the setting temperature (RT), temperature stability time (TST) and temperature hunting (TH) were measured and compared with the existing pressure rollers case. The RT of A roller was shortened by 50minutes, and B roller was shortened by 15minutes. The TST of A roller was shortened by 13minutes, and B roller was shortened by 15minutes. The THs of both A and B rollers were settled up to ${\pm}5^{\circ}C$. Finally, the productivity of the FCLM and the quality of the FFC were increased.