• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.15-22
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• 2009

In this paper, a sensorless control of PMSG(Permanent Magnet Synchronous Generator) for small wind turbine systems, which is based on stator flux and back-emf estimation. Also, a cost-effective AE/DC/AC converter that consists of a two-leg three-phase PWM converter and a half-bridge PWM converter is used for vector control of PMSG, which is impossible with the conventional diode-rectifier type converter. A sensorless control algorithm can eliminate pulse encoders for speed measurement, which reduces the system cost. Using PSIM simulation, the validity of the converter control performance and MPPT control of PMSG have been verified.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.111-113
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• 2007

본 논문에서는 FPGA를 사용하여 진행파형 초음파 모 터의 2상 입력 전원 전압의 주파수, 위상차, 진폭 및 2 상간의 전압차 조절이 가능하고, 8대의 초음파 모터를 동 시에 제어할 수 있는 8채널 USB통신 PC기반 초음파 모터 디지털 제어기를 제안한다. 제안한 제어기는 FPGA를 이용 한 디지털 논리에 의해 출력을 발생하기 때문에 PC로부 터 직접 제어 명령을 입력 받아 각각의 파라미터를 실시 간으로 조절할 수 있을 뿐만 아니라, 둘 이상의 파라미터 를 동시에 조절이 가능하다. 또한, PC와의 인터페이스는 USB통신 방식을 채택하여 제어 명령의 전달속도 향상 및 플러그 앤 플러그 방식을 통해 데스크 탑 컴퓨터는 물론 휴대용 컴퓨터나 PDA와 같은 다양한 플랫폼에서 사용할 수 있도록 설계하였다. 또한, 초음파 모터의 속도 및 위치를 계측하기 위해 사용된 로터리 엔코더 카운터 회로를 FPGA회로에 내장시켜 카운터를 위한 별도의 회로 구성이나 장비 구입의 필요성을 배제하였다. 따라서, 생산 단가 및 부피를 현저히 감소시켰다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.2
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• pp.170-177
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• 2011

This paper proposes a telemetering method that transmits the real-time data together with the time-delayed data and that merges both data after flight test. The method can minimize the error data which occur in the communication environment affected by the multipath fading and transmit antenna pattern when telemetry data are received during the flight test. This method was applied to the design of the telemetry unit and the development of data merging program. By merging the resulting data of flight test and analyzing synchronization errors, its efficiency for the telemetry link is verified.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.29.1-29.1
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• 2010

GPS(Global Positioning System)로 대표되는 위성항법시스템(GNSS: Global Navigation Satel lite System)은 우주공간의 위성을 이용하여 사용자에게 위치와 함께 시각 정보를 제공해 준다. 위성항법시스템은 항법 분야 뿐 아니라 측량, 측지를 비롯하여 정밀 시각동기 및 지각변동의 측정까지 다양한 분야에서 활용되고 있다. 항법분야에 있어서 위성항법시스템의 오차를 제거한 정밀한 위치 정보를 이용하여 이동체에 활용하는 연구가 활발히 진행되고 있다. 위성항법을 움직이는 이동체에 적용할 경우 주변 환경에 따라 위성항법 신호의 오차가 증가하여 급격한 위치 오차를 유발하므로 추가적인 센서 사용을 통하여 안전성을 향상시킬 필요가 있다. 이 논문에서는 위성항법 기반의 위치정보와 이동체에 부착되어 있는 센서 정보를 병렬적으로 사용하는 주행시스템을 구성하고 주행 시험을 수행하였다. 이동체에 부착되어 있는 센서 정보를 이용한 주행시스템의 경우 이동 거리를 측정할 수 있는 엔코더와 조향각을 측정할 수 있는 포텐셔미터 그리고 차량 모델을 이용하여 구성하였다. 시험 결과 위성항법기반의 위치 정보와 이동체의 센서 정보를 이용한 위치 오차의 차이는 0.4m 이내로 위성항법 신호에 급격한 오차가 들어오는 경우 이동체의 센서 정보를 이용하여 감지할 수 있음을 확인하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.6
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• pp.563-569
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• 2006

In this paper, the system to control the PWM inverter-induction motor drive system including ac current sensors, voltage sensors, and an encoder through the network is developed. Although the network-based control for an induction motor drive system is becoming increasingly important at factory automations, there will inevitably be time delay from the sensors to the motor control system, which may cause the instability. The algorithm to minimize the efforts for network induced time delay of sensor data is proposed, using both the synchronous signal and the method for estimating sensor data. The experiments with DSP are carried out in order to verify proposed algorithms.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.5
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• pp.448-456
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• 2004

This paper presents a new method of detecting rotor position in Toroidal Switched Reluctance Motor (TSRM). In this paper, low cost and robust characteristics of rotor position detection method are focused in order to compensate for disadvantage of general sensors. Search coils wound through the hole of the stator poles are used for detection of the rotor position in TSRM. Rotor position detection is achieved through electromotive force patterns induced by time-varying flux linkage in the search coils and then adequate phase is excited for drive. The validity of the method is verified by experimental results.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.11
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• pp.117-124
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• 2004

Recently, nano-methodology is increasingly important as the ruler for measuring nano-technology, and we applied the linear encoder to nano-methodology. The quadrature output in the linear encoder has an effect on increasing the resolution in some techniques. Already, various interpolation techniques based on the quadrature signal have applied to the precision servo system. In this paper, we propose a new interpolation algorithm for ultra-precision positioning in the low speed with simulation by MATLAB SIMULINK. This method modified previous methods and was properly designed for some given control system. To verify, we first fulfilled the encoder signal test to find main parameters fer the signal transformation, then we proved the proposed interpolation algorithm by experiments, which show that the result of the interpolation algorithm corresponds with the measurement of the laser interferometer in 100 nm unit approximately. In addition, we can get more precise measurement by more accurate and noise-free signal. So we need to compensate imperfections in the encoder signal. After that, we will apply this algorithm to nano positioning system.

• Journal of Advanced Navigation Technology
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• v.10 no.3
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• pp.191-197
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• 2006

In the paper propose a sensorless sliding mode control method of an induction motor using an adaptive speed control. The control objective is apply to adaptive speed observer instead of a encoder and to remove errors using the sliding mode current controller by parameters variation and disturbances that include the current controller. A stability of the sliding mode current controller and the adaptive speed observer using a design controller is guaranteed by the Lyapunov stability criterion. The performance of the proposed control system is demonstrated by simulation using the matlab silmulink and experimental results using induction motor show that the proposed method can apply an induction motor control.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.181-186
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• 2022

There is a demand for an intermodal automatic transport bogie as a means for efficient logistics transport. Intermodal is characterized by high demand for single-track operation in a specific section in connection with heterogeneous transportation means. In this study, a driving information system that is simple and optimized for the intermodal automatic transportation bogie is implemented to be suitable for the characteristics of the inter-modal automatic transportation bogie, unlike the existing railroad operation system, and applied to a real large-scale demonstration model to ensure in-place stopping and a smooth interface between each system. and operational examples with a simplified system.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.86-92
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• 2001

Position controls are very important in semiconductor manufacturing devices, machine tools, precision measuring instruments, etc. to measure the distance of movement of moving objects in minute units and the accuracy of measurement for the moving distance in these devices affect the performance of the whole devices. Therefore, in those precision instruments, a sensing device that can measure the distance of movement with high-precision resolution is required. Thus an optical encoder that has such advantages as easy digital interface, economical price, and a resolution similar to that of laser interferometers can be used. In this paper, a interferometer-type linear scale with easy digital interface and high-resolution has been set up and measured the distance of movement based on the diffraction principle. Interference signals produced in this optical setup of the linear scale have beers digitalized through fabricated photodetectors and designed signal processing circuits. A resolution of 0.5${\mu}{\textrm}{m}$ is acquired from the experimental interferometer-type linear scale without for the movement of scales any additional dividing circuits. It is shown that from this experiment a high-resolution distance measurement device can be designed by a simple optical setup.