• 한국정밀공학회지
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• 제14권4호
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• pp.88-96
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• 1997

This paper suggests a new non-linear friction compensation for digital control systems. This control adopts a hysteresis nonlinear element which can introduce the phase lead of the control system to compensate the phase delay comes from the inherent time delay of a digital control. A proper Lyapunov function is selected and the Lyapunov direct method is used to prove the asymptotic stability of the suggested control.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.987-993
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• 1996

This report suggests a new non-linear friction compensation for digital control systems. This control adopts a hysteric nonlinear clement which can introduce the phase lead of the control system to compensate the phase delay comes from the inherent time delay of a digital control. The Lyapunov direct method is used to prove the asymtotic stability of the suggested control, and the stability and the effectiveness are verified analytically and experimentally on a single axis servo driving system.

• 융합신호처리학회논문지
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• 제14권2호
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• pp.136-146
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• 2013

본 논문에서는 FX 형식의 한일상관기(Korea-Japan Joint VLBI Correlator, KJJVC)의 잔차 지연 보정 알고리즘을 제안하였다. KJJVC의 초기 잔차 지연보정 알고리즘에는 연산의 고속화를 위해 정수 연산과 위상보정 계수를 위한 cos/sin table을 도입하였다. 그리고 잔차 지연 알고리즘의 초기설계에서 데이터의 타이밍과 잔차 지연 위상의 불일치와 비트쉬프트와 잔차 지연 위상의 불일치 문제를 해결하였다. VCS의 잔차 지연 알고리즘의 최종 설계에서는 잔차 지연보정된 값을 FFT segment에 적용할 때 잔차 지연 보정 회전 메모리가 초기화 되지 않는 것을 수정하였다. 제안한 잔치 지연 보정 알고리즘을 이용하여, 교차 전력 스펙트럼의 대역폭 모양이 모든 대역폭에 대해서 손실이 없이 평탄한 것을 확인하였다. 제안한 잔차 지연보정 알고리즘의 유효성을 확인하기 위해 시뮬레이터와 KJJVC를 이용하여 실제 관측데이터를 대상으로 상관처리 시험을 수행하였다. 실험결과를 통하여 제안한 잔차 지연 보정 알고리즘이 KJJVC에 잘 적용되고 있으며, 신호대 잡음비가 약 8% 향상되는 것을 확인하였다.

• 한국전자파학회논문지
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• 제26권9호
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• pp.790-797
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• 2015

본 논문에서는 마이크로파용 소프트웨어 기반 폴라 송신기를 구현하고, 경로 간의 동기화를 분석하였다. 폴라 송신기의 위상신호와 진폭신호의 두 경로 간 시간 지연부정합 문제를 해결하기 위해 단순화된 보정알고리즘을 적용하였으며, 보정 전과 보정 후의 두 경로 간 동기화 결과를 비교하였다. 동기화 보정하기 전, 9.3 GHz에서 두 경로 간 지연부정합은 최대 97 nsec가 발생하였으며, 이에 따른 점유대역폭은 12 MHz이었으며, 제안한 보정알고리즘을 적용한 결과, 두 경로 간 동기화를 이루었고, 점유대역폭도 기존의 3.7 MHz로 복원할 수 있음을 확인하였다.

• Current Optics and Photonics
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• 제8권1호
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• pp.56-64
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• 2024

In response to the current situation where general methods cannot effectively compensate for the phase delay of ordinary optical mixers, a multi-layer spatial beam-splitting optical mixer is designed using total reflection triangular prisms and polarization beam splittings. The phase delay is generated by the wave plate, and the mixer can use the existing parallel plates in the structure to individually compensate for the phase of the four output beams. A mixer model is established based on the structure, and the influence of the position and orientation of the optical components on the phase delay is analyzed. The feasibility of the phase compensation method is simulated and analyzed. The results show that the mixer can effectively compensate for the four outputs of the optical mixer over a wide range. The mixer has a compact structure, good performance, and significant advantages in phase error control, production, and tuning, making it suitable for free-space coherent optical communication systems.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권8호
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• pp.377-386
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• 2005

This paper presents the control algorithm of single-phase hybrid active power filter for the compensation of harmonic current components in nonlinear R-L load with passive active Power filters. To construct two phase system, an imaginary second phase was made. In this proposed method, the new signal which is the delayed through the filtering by the phase-delay property of low-pass filter is used as the secondary phase. Because two-phases have the different phase, the instantaneous calculation of harmonic current is possible. In this paper, a reference voltage is created by multiplying the coefficient k by the compensation current using the rotating reference frame synchronized with the source-frequency, not applying to instantaneous reactive power theory which has been used with the existing fixed reference frames In order to verify the validities of the proposed control methods, experiments are carried out with the prototypes of single-phase hybrid active power filter.

• Journal of Power Electronics
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• 제9권5호
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• pp.718-725
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• 2009

To get instantaneous reference data in a single power system with vector space phasors, the instantaneous load current is adopted as a phase and another new signal, which is delayed through filtering by the phase-delay property of a low-pass filter, is used as the secondary phase. Because the two-phases have a different phase, the instantaneous value of the harmonic current can be obtained without a time-delay in calculation. The reference voltage is created by multiplying the coefficient k by the compensation current using the rotating reference frame synchronized with the source-frequency. To verify the validity of the proposed control method, experiments are carried out on a prototype of the single-phase hybrid active power filter system.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권3호
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• pp.179-192
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• 2008

A multiphase compensation method with mismatch linearization technique, is presented and demonstrated in a $\Sigma-\Delta$ fractional-N frequency synthesizer. An on-chip delay-locked loop (DLL) and a proposed delay line structure are constructed to provide multiphase compensation on $\Sigma-\Delta$ quantizetion noise. In the delay line structure, dynamic element matching (DEM) techniques are employed for mismatch linearization. The proposed $\Sigma-\Delta$ fractional-N frequency synthesizer is fabricated in a $0.18-{\mu}m$ CMOS technology with 2.14-GHz output frequency and 4-Hz resolution. The die size is 0.92 mm$\times$1.15 mm, and it consumes 27.2 mW. In-band phase noise of -82 dBc/Hz at 10 kHz offset and out-of-band phase noise of -103 dBc/Hz at 1 MHz offset are measured with a loop bandwidth of 200 kHz. The settling time is shorter than $25{\mu}s$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.149-151
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• 2005

This paper deals with the novel control algorithm of single-phase hybrid active power filter for the compensation of harmonic current components in nonlinear R-L load with passive active power filters. To construct two-axes coordinate, an imaginary second phase was made by giving time delay to line current. In this proposed method, the new signal, which was the delayed through the filtering by the phase-delay property of low-pass filter, is used as the secondary phase. Because two phases have different phase, instantaneous calculation of harmonic current is possible. In this paper, a reference voltage is created by multiplying gain of filter by compensation current using the rotating reference frames that synchronizes with source-frequency, not applying to instantaneous reactive power theory which has been used with the existing fixed reference frames. This paper shows the experimental results, which provide a high accuracy and extremely fast response of single-phase hybrid active Bower filter under the operation with the proposed control method.

• 한국전자파학회논문지
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• 제23권10호
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• pp.1212-1215
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• 2012

레이다 간섭계에서 표적의 공간 도달 각도를 추정하는 방법 중에서 위상 비교 모노 펄스 알고리즘의 추정 각도 정확도를 향상시키기 위한 위상평균법 및 시간 지연 보상 방안을 제안하였다. 실시간 신호처리 시스템에 적용할 경우, 저역 통과 필터의 특성을 갖는 위상평균법을 적용하면 필연적으로 시간 지연이 발생한다. 이 문제점을 보완하기 위해 곡선 맞춤법을 이용하여 추정된 각도의 변화율을 계산하고 보상하여 실시간 신호처리 시스템에 적용 가능하도록 하였다. 제안 방법의 효용성을 입증하기 위해 실제 레이다 간섭계를 이용하여 획득된 데이터에 적용하여 추정된 각도의 정확도를 비교하였다.