• 한국정보통신학회논문지
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• 제3권4호
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• pp.907-914
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• 1999

This paper studies on the model identification of electro-hydraulic servo systems, which are composed of servo valves, double-rod cylinder and load mass. The identified plant is described as a discrete-time ARX or ARMAX model which is respectively obtained from the identification algorithms of least square error method, instrumental variable method and prediction error method. where a nominal model and the variation of model parameters are quantitatively evaluated.

• 한국정보통신학회논문지
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• 제15권5호
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• pp.1207-1212
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• 2011

본 논문은 BLDC 서보모터 펌프를 사용하는 PBW(power-by-wire) 시스템을 위한 DSP(Digital Signal Processor) 제어기에 대한 연구를 제시한다. PBW 유압 엑츄에이터는 BLDC 서보모터에 의해 구동되는 유압펌프와 유압 실린더 그리고 제어기로 구현된다. 이 PBW 시스템은 유압 실린더의 선형 추진 동작을 위해 서보 모터의 속도 제어를 필요로 한다. 본 논문에서는 벡터 제어 방법과 MIN-MAX PWM 기술을 활용하는 서보 제어기를 구현한다. 제어기로서, PWM 파형발생기, A/D변환기, SPI(직병렬인터페이스) 포트 그리고 많은 입/출력 포트 등을 가지고 있는 이유로 TMS320F2812 DSP가 채택되었다.

• 제어로봇시스템학회논문지
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• 제14권3호
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• pp.263-272
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• 2008

We implemented a real-time servo system for a manipulator based on Laser Range Finder (LRF). and established algorithms for grasping a moving cylinder. We devised a manipulator mechanism and driving hardware based on a system board equipped with Xscale Processor with real-time operating system RTAI on Linux. The manipulator motor driver is connected to the system board via CAN communication link, and LRF is connected via RS-232C. We implemented real-time software including CAN device driver, RS-232C device driver, manipulator trajectory generator, and LRF control software. A typical application experiment for grasping a cylinder with circle motion demonstrated our system's real-time performance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.71-75
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• 1994

This paper presents a method of optimal design of an automatic transfer system which is controlled by the electro-pneumatic servo scheme. The electro-pneumatic automatic transfer system can move parts to desired points or displace defective parts. The dynamic performance of the system can be examined by observing the behavior of the output. The output of the servo control system is the motion of the cylinder, pneumatic actuator. The dynamic performance of the cylinder is governed by the parameters of the components of the entire system. The optimal design can be accomplished by selecting of the parameters such that the desired dynamic performance of the cylinder is obtained. The optimal set of parameters might be obtained through the repeated simulations. Repeated simulations, however, is not effective to determine the optimal set of parameters since the set of parameters is large. This paper presents modeling, application of an optimization method, and the numerical results. The optimization algorithm utilizes the concept of the conjugate gradient method. The results show that the suggested optimization scheme can render faster convergence of iteration compared to other method based on an algebraic optimization method and can reduce the design efforts.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.817-818
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• 2013

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.730-735
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• 1992

In this study, heavy loads driving servo control systems, which are composed of electro-hydraulic servo-valve, hydraulic motor/cylinder, gear box and link mechanism, are investigated for implemention. To predict the performances of the systems, modelling and simulation with some nonlinearities are carried out. Simulation results are compared with experimental results.

• 한국자동차공학회논문집
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• 제22권5호
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• pp.108-115
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• 2014

In this study, experimental approaching method was applied under and single-cylinder engine to research the performance of direct needle-driven piezo injector (DPI) for CR direct-injection. As key-point factor of this DPI that relies on direct-acting operating of injector needle, unlike conventional hydraulic-servo, its nozzle needle can be directly driven by piezo actuator. Thus, effect of direct-acting injection of DPI on diesel combustion and emission characteristics was investigated under common-rail single-cylinder direct-injection engine, equipped with three different driving mechanism, including indirect-acting solenoid, piezo and DPI system. As main results, it found that a direct-acting piezo injector has higher of IMEP. And it has higher heat release rate during premixed combustion and mixing controlled combustion phase due to its higher heat release, even though nitrogen oxide (NOx) formations were increased slightly.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.1-6
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• 1989

For the design of synergistic hydraulic motion simulator, the load locus method is introduced. The given mass property of load and its velocity profile is resolved into the load locus of each actuator which decides the suitable valve and cylinder. This asymmtic cylinder and 4 way valve system have the pressure oscillation on zero velocity. The variable structure position controller which based on linearized flow equation makes elimination of the unstable pressure oscillation.

• 한국산업융합학회 논문집
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• 제25권5호
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• pp.881-888
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• 2022

Servo presses are used in variety of ways in industry throughout the production and assembly lines of machine parts. The bottom of the servo press is fixed to a bed or a tabletop, and the press cylinder continuously operates under vertical upward loads. In this research, a static structural analysis was performed by simplifying 3D model of the servo press, and the maximum deformation was applied to the clamp and bolt. The maximum value of Von Mises stress was reported in this paper. The result was used to calculate the safety factor, and it was confirmed that the design was conservative.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.985-990
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• 2007

This paper presents a novel control algorithm for position control of pneumatic cylinder. Generally, it is difficult to control the pneumatic servo system, due to nonlinearities such as air compressibility, the opening area of the valve, and frictional force between the cylinder and the piston. Especially, it is of significant importance for the control consisten-cy to return the cylinder pressures at equilibrium point to the initial states, still with guaranteeing the continuity of the pressures. For this purpose, the proposed control algorithm makes pressures of both cylinder chambers identical in magnitude but different in direction. The effectiveness and practicability of the control algorithm for the precise position control of the pneumatic cylinder are verified through the simulation study.