• Journal of Institute of Control, Robotics and Systems
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• v.18 no.7
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• pp.627-631
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• 2012

Observable mathematical model of DDM (Direct Dirve Motor) was suggested. The motor that operates the object system directly is called DDM. DDM has many strong points, however, it has a significant disadvantage, that it is more sensitive to the external force than the motor with reduction gear. In other word, if the force is applied, air gap of the motor can be perturbed. This causes not only difficulty in motor control but also even more serious problem, such as the breakdown of motor. However, if the air gap variation can be estimated, it can help prevent these problems. DDM should be modeled to estimate the air gap variation. The type of researched DDM is PMSM (Permanent Magnet Synchronous Motor) and precedent model of PMSM includes only characteristics of electro-magnetic system and rotational motion. However, suggested model should also include characteristics of translational motion of rotor to estimate the air gap variation. Also, this model should satisfy observability condition, because state observer is designed based on this model.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.1
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• pp.93-97
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• 2007

In this paper a new clock generation scheme for TDM-CDM converter in the Gap Filler for satellite DMB systems has been proposed. The scheme uses the frame sync signal from the Ku band TDM receiver to lock the VCXO which provides the system clock for the TDM-CDM converter. The locking algorithm can be easily implemented in the FPGA, so that no separate circuitry is needed as in conventional PLL. With a stable OCXO, The scheme can be used to generate the reference clock to the local oscillator for RF parts.

• 열병합발전
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• s.77
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• pp.18-22
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• 2010

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.99-99
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• 2012

본 개발에서는 초고속복합분자펌프 구동을 위한 디지털 구동장치를 설계하였다. BLDC구동을 위한 디지털 제어 시스템의 핵심제어 보드 설계 및 모듈 설계를 하여 보드제작 및 기본성능평가를 하고 고속 회전 실험을 하였다. AMB제어기는 넓은 제어대역폭을 확보하기 위하여 FPGA 1개와 마이크로 콘트롤러 2개를 사용하여 구성하였으며 FPGA로 AMB구동을 위한 PWM기능과 CPU 2개의 원활한 Data 통신을 위하여 Dual Memory을 구현하였으며 PWM의 디지털노이즈 회피를 위하여 AMB구동용 PWM과 동기화하여 Gap Sensor 및 전류센서신호 샘플링할 수 있도록 ADC를 구동 및 샘플링한다. 그리고 Gap Sensor 구동 회로와 제어기회로를 하나의 보드로 구연하였다.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.2 s.152
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• pp.101-110
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• 2007

Recently, rudder erosion due to cavitation frequently has occurred at large high speed container carriers. Especially, in the case of a horn-type rudder, the rudder erosion is severe around a gap. The gap-flow characteristics are investigated through a computational method to understand the effects of a gap on the cavitation and rudder efficiency. A viscous flow theory utilizing a cavitation model is applied to calculate the flow around idealized 2-dimensional rudder sections in a full scale. The effects of gap clearance and flow-control projection are also investigated. From the computational results, the mass flow rate through a gap is found to be one of the important parameters to affect the cavitation and rudder efficiency.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.52-55
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• 1997

This paper discusses an automatic visual-servoing system, in which a laser and a CCD camera are used for imaging the pattern of joint groove. The algorithm used here is simple and robust to find out the gap width and gap center. As a consequence, the speed of algorithm is very fast and optimized. A feature of this system is that it processes only by summing the vertical line and horizontal line of screen without any image preprocessing in order to get the energy information of lines alternatively. It is practical and useful for the system requiring a fast process time of vision.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.51-54
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• 2003

진화하드웨어는 하드웨어 스스로 진화하여 필요한 회로를 구성한다 회로를 재구성하기 위해서 유전자 알고리즘을 사용한다. 유전자 알고리즘(Genetic Algorithm)은 전역적 탐색을 통하여 해를 구한다. 하지만 유전자 알고리즘은 많은 개체의 평가를 통하여 이루어지기 때문에 수행하는데 시간이 많이 소요된다. 이전의 연구에서 유전자 알고리즘 프로세서를 이용하여 진화하드웨어를 구성했다. 유전자 알고리즘 프로세서는 유연성이 떨어지고 범용적으로 사용하기 어렵다. 본 논문에서는 CPU를 이용하여 유전자 알고리즘 프로세서를 소프트웨어로 제어하는 방법을 제안한다 소프트웨어로 합성한 신호로 GAP의 동작을 제어하기 때문에 유연성을 가질 수 있다 FPGA에 CPU와 유전자 알고리즘 프로세서를 구현하여 one-chip 하드웨어를 구현한다.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.626-630
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• 2005

This paper presents a novel Intelligent-Welding-Carriage (IWC) for automation of curved block in shipbuilding. The curved block is usually used in both front and back side of the ship. In curved block root gap is big, $1{\sim}7$ [mm] and inclination, $0{\sim}30$ [deg]. Since available conventional carriage type is limited to use below root gap of 3 [mm], only manual welding is employed in curved block. To adopt an IWC in curved block, it requires control of the welding conditions, i.e., voltage, current and travel speed, with respect to root gap and inclination to achieve good welding quality. In this paper, an IWC is developed for automization of welding operation to accommodate gap and inclination. Kinematics model and dynamics using Lagrangian formulation of the manipulator is introduced. IWC utilizes a database to perform accurate welding. The database is programmed based on numerous experimental test results with respect to gap, inclination, material, travel speed, weaving condition, voltage, and current. Finally, experimental result using PID control is addressed for verify the trajectory tracking accuracy of end-effector.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.794-797
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• 1988

G. Binnig and H. Rohrer introduced the Scanning Tunneling Microscope (STM) in 1982 and developed it into a powerful and not to be missed physical tool. Scanning tunneling Microscopy is a real space surface imaging method with the atomic or subatomic resolution in all three dimensions. The tip is scanned over the surface by two piezo translators mounted parallel (X-piezo and Y-piezo) to the surface and perpendicular to each other. The voltage applied to the third piezo (Z-piezo) translator mounted perpendicular to the surface to maintain the tunneling current through the gap at a constant level reflects then the topography of the surface. The feed back control loop for the constant gap current is designed using the automatic control technique. In the designing process of the feed back loop, the identification of the gap dynamics is very complex and has difficulty. In this research, using some suitable test signals, the system dynamics of the gap including the Z-piezo are investigated. Especially, in this paper, a system model is proposed for the gap and Z-piezo series system. Indicial response is used to find out the model. The driving voltage of the Z-piezo and the tunneling current are considered as input and output signals respectively.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.699-703
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• 1991

A magnetic levitation system with hybrid magnets, which is composed of permanent magnets and electromagnets, consumes less power than the conventional attraction type system. In this paper, we propose PID controller and PID-Fuzzy controller for hybrid magnet. We first present "constant gap" control technology with PID controller. Secondly, "zero power" control technology with PID-Fuzzy hybrid controller is presented.roller is presented.