• 제목/요약/키워드: Waveform control

검색결과 564건 처리시간 0.031초

고음질 합성용 스펙트럼 보상된 시간축조절 피치 변경법 (On a Pitch Alteration Method by Time-axis Scaling Compensated with the Spectrum for High Quality Speech Synthesis)

  • 배명진;이원철;임성빈
    • 한국음향학회지
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    • 제14권4호
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    • pp.89-95
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    • 1995
  • 파형부호화법은 음성신호에서 잉여성분 제거과정을 통해 유용한 파형의 꼴을 단순히 보존하는 방법이다. 음성합성분야에서 고음질의 파형부호화법은 분석에 의한 합성방식으로 주로 적용된다. 그렇지만 이러한 부호화법에서 파라미터들은 여기용과 성도 여파기용으로 분리되지 않기 때문에 이 파형부호화법을 규칙에 의한 합성 방식으로 사용하기는 어렵다. 파형부호화합을 규칙합성에 적용하려면 운율조절을 위해 피치변경법이 필요하다. 본 논문에서는 시간축 스케일링과 주파수상에서의 스펙트럼 보정을 통해 파형부호화법에서 피치를 변경할 수 있는 새로운 피치변경법을 제안하였다. 이 방식은 파형의 위상성분을 보존하는 시간-주파수 혼성법이고, 50%의 피치변경을 수행하였을 때 2.5%정도의 스펙트럼 왜곡을 나타내었다.

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FPGA를 이용한 피에조 부하 구동용 고전압 단방향 인버터의 PI 및 히스테리시스 전압 제어 특성 비교 (Characteristic Comparison between PI and Hysteresis Voltage Control of High Voltage Unidirectional Inverter for Piezoelectric Load using FPGA)

  • 김기석;조용호;김형섭;강태삼;홍선기
    • 전기학회논문지
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    • 제66권1호
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    • pp.48-54
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    • 2017
  • In this paper, hysteresis voltage control method is proposed to an unidirectional inverter control for piezoelectric load. Piezoelectric load has electrically RC characteristic, and is driven by the inverter to control the output voltage waveform. When controling the output waveform by PI control, appropriate gains need to be selected. However, hysteresis control may minimize the output distortion because it has maximum proportional gain. In addition, Hysteresis control algorithm has simple structure to realize and the response is fast. Although the switching frequency of the inverter by hysteresis control varies, the switching frequency for the piezoelectric load is lower than that by PI control for equivalent performance. In particular, on implementing the algorithm using FPGA, the algorithm can be implemented in fewer pabrics and the processing time can be reduced. The superiority of the proposed hysteresis voltage control was proved for piezoelectric load through simulation and experiment.

차량 드로틀 보디 전장부품의 품질관리 성능시험 알고리즘 개발 (Development of Algorithm of Surge Test for Quality Control on Electrical Parts of Throttle Body in Automobiles)

  • 손재환;김태한
    • 한국산업융합학회 논문집
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    • 제9권1호
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    • pp.67-72
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    • 2006
  • This study is on the development of algorithm of surge test for quality control on electrical parts of throttle body in automobiles with internal combustion engine, not only to know its condition to be good or not, but also jugding its condition to be classified into six types. To know whether its condition to be good or not, comparing and analyzing between two waveforms generated from master and test coil of throttle body. If test net area is below 20% of master area, the condition of test coil is good. By analyzing test coil waveform to master coil waveform, the condition of test coil into winding badness, insulation badness, layer and corona discharge, short badness should known. Therefore quality control system on electrical parts of throttle body should be developed.

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Development of a stroke output control algorithm using a fuzzy logic for a left ventricular assist device

  • Choi, Jae-Soon;Choi, Won-Woo;Park, Seong-Keun;Park, Seong-Keun;Min, Byoung-Goo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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    • pp.514-517
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    • 1995
  • A new stroke output control algorithm with a fuzzy logic for an electrohydraulic left ventricular assist device(EH-LVAD) was developed. The EH-LVAD pumps out blood from left atrium actively. Excessive suction of blood may cause fatal damage in left atrium. The LVAD has to provide a maximal stroke output without collapse of left atrium. In this study a new fuzzy algorithm for predicting and detecting suction and doing proper action on LVAD without using an extra pressure sensor but with bellows pressure signal and motor current signal is developed. The performance of the fuzzy control algorithm is demonstrated by the results from mock circulatory experiments.

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3상 레귤러 샘플링 PWM 인버터의 출력파행 분석에 관한 연구 (A Study on the Analysis of the Output Waveform of Three-Phase Regular Sampling PWM Inverter)

  • 노창주
    • 수산해양기술연구
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    • 제28권3호
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    • pp.274-285
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    • 1992
  • Among various Power converters, a variable voltage variable frequency (VVVF) three-phase PWM inverter is regarded as most promising power converter due to its capabilities, which permits the control of voltage, frequency and harmonic contents in a single power stage employing only on DC source. As a modulating technique of the PWM inverter, the regular sampling technique has rendered possible the on-line computation and generation of PWM control waveforms with a reasonably high switching frequencies. In this paper, microprocessor based three-phase regular samping PWM inverter with real-time control algorithm and control circuits for driving three phase AC motor has been developed. Harmocic components of PWM waveform were analized theoretically in terms of Bessel function series and then calculated by digital computer and observed with spectrum analyzer.

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최적 전류파형제어를 통한 브러시리스 DC 발전기의 출력밀도 최대화에 관한 연구 (Power Density Maximization of the Brushless DC Generator by Controlling the Optimal Current Waveform)

  • 이형우
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제53권7호
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    • pp.430-436
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    • 2004
  • This paper presents an advanced control technique for power density maximization of the Brushless DC (BLDC) generator by using the linear tracking method. In a generator of given rating, the weight and size of the system affect the fuel consumption directly. Therefore, power density is one of the most important issues in a stand-alone generator. BLDC generator has high power density in the machine point of view and additional increases of power density by control means can be expected. Conventional rectification methods cannot achieve the maximum power possible because of hon-optimal current waveforms. The optimal current waveform to maximize power density and minimize machine size and weight in a nonsinusoidal power supply system has been derived, incorporated in a control system, and verified by simulation and experimental work. A new simple algebraic method has been proposed to accomplish the proposed control without an FFT which is time consuming and complicated.

컨트롤 차트를 이용한 고조파 전압 왜곡 발생원 관리기법 연구 (Study of Harmonic Sources Management Method using Control Chart)

  • 한종훈;이계병;장길수;박창현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.197-198
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    • 2011
  • A technique to manage harmonic pollution at the point of common coupling (PCC) has been presented using a control chart. The recursive least-squares technique has been used to estimate the parameters of the Thevenin equivalent load model. With the estimated data from the measured voltage and current waveform at the PCC during certain period violating upper control limit, the individual contributions to the distortion of voltage waveform at an interested harmonic frequency have been calculated and shown by simple graph.

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A Study on Isolated DCM Converter for High Efficiency and High Power Factor

  • Kwak, Dong-Kurl
    • Journal of Electrical Engineering and Technology
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    • 제5권3호
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    • pp.477-483
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    • 2010
  • This paper is studied on a novel buck-boost isolated converter for high efficiency and high power factor. The switching devices in the proposed converter are operated by soft switching technique using a new quasi-resonant circuit, and are driven with discontinuous conduction mode (DCM) according to pulse width modulation (PWM). The quasi-resonant circuit makes use of a step up-down inductor and a loss-less snubber capacitor. The proposed converter with DCM also simplifies the requirement of control circuit and reduces a number of control components. The input ac current waveform in the proposed converter becomes a quasi sinusoidal waveform in proportion to the magnitude of input ac voltage under constant switching frequency. As a result, it is obtained by the proposed converter that the switching power losses are low, the efficiency of the converter is high, and the input power factor is nearly unity. The validity of analytical results is confirmed by some simulation results on computer and experimental results.

모터구동형 완전이식 인공심장에서 전류파형의 분석에 의한 심박출량 자동제어 알고리즘의 개발 (A Study On the Automatic Cardiac Output Control Without Pressure Sensors for the motor-driven Totally Implantable TAH Using Motor-Current Waveform Analysis)

  • 최원우;김희찬;민병구
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1992년도 추계학술대회
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    • pp.130-135
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    • 1992
  • In this paper a new cardiac output control method without pressure sensors is presented for the rotor-driven totally implantable TAH using motor-current wavelet analysis. Theoretical analysis and mock circulation system experiment results show that cardiac output of TAH, which is indeperdent of afterload and sensitively dependent to preload, is well controlled for the independently variable preload.

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신경회로망기법을 이용한 SRM 드라이브의 토오크리플 저감방안 (Torque Ripple Reduction Method of SRM Drives Using Neural Network Technique)

  • 이성두;정태욱;안진우;황영문
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 A
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    • pp.227-229
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    • 1997
  • The torque of SRM is developed by phase currents and inductance variation. The inductance of torque generation region is nonlinearly varied according to phase current. By this nonlinear characteristics, torque ripple can be generated on the condition of constant current. Otherwise, phase current should be controlled instantaneously in accordance with inductance to reduce torque ripple. In this paper, the control system with neural network that can reduce torque ripple is suggested. In this control system, instantaneous inductance and optimal current waveform for smallest torque ripple is obtained by neural network. And this required optimal current waveform is regulated by voltage control.

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