• 제목/요약/키워드: Predictive

검색결과 5,234건 처리시간 0.034초

매트릭스 컨버커를 위한 새로운 예측 전류제어 펄폭 변조 방법 (Novel Predictive Current Control Pulse Width Modulation Method for Matrix Convertors)

  • 리위룽;최남섭;한병문;양승철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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    • pp.65-67
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    • 2008
  • A new pulse width modulation method based on predictive current control strategy is proposed to modulate matrix converters. The predictive current controller utilizes a discrete-time model to predict the future values of output currents and generates proper duty-ratios ta minimize the output current errors. The proposed method uses continuous carrier and establishes a predictive current controller to predetermine duty ratio signal for directly generating gating signals an thus is named "predictive current control PWM(PCCPWM)". The modulation algorithm nd the required equations are derived by using average concept over one switching period. Thus it can be easily extended to other matrix converter topologies, especially with neutral connections, such as sing le-phase ad two-phase matrix converters. The feasibility and validity of the proposed strategy are verified by computer simulation and experimental results.

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멀티쓰레드와 SIMD 명령어를 이용한 실시간 H.264/AVC High 4:4:4 Predictive 디코더의 구현 (Real-time H.264/AVC High 4:4:4 Predictive Decoder Using Multi-Thread and SIMD Instructions)

  • 김용환;김재우;최병호;이석필;백준기
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2007년도 학술대회
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    • pp.350-353
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    • 2007
  • This paper presents an real-time implementation of H.264/AVC High 4:4:4 Predictive profile decoder using general-purpose processors by exploiting multi-threading technique and Single Instruction Multiple Data (SIMD) instructions without any quality degradation. We analyze differences between the existing High profile and High 4:4:4 Predictive profile decoder, and show various optimization techniques to decode high fidelity and high definition (HD) video in real-time. Simulation results show that the proposed decoder can play high fidelity HD video at average 40 frames per seconds (fps) for the IBBrBP bistream and about 50 fps for the Intra-only bitstream.

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비례전자 감압밸브의 모델링과 제어 (A Modeling of Proportional Pressure Control Valve and its Control)

  • 양경욱;이일영
    • 동력기계공학회지
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    • 제6권3호
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    • pp.71-77
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    • 2002
  • In this study, a dynamic model of proportional pressure control valve using the bond graph and a predictive controller are presented in the form of dynamic matrix control which is concerned with a design method of digital controller for the electro hydraulic servo system. The bond graph can be utilized for all types of systems which involve power and energy, and it is applied to a propotional pressure control valve in this study. Recently, many researchers suggested that better control performance could be obtained by means of the predictive controls with future reference input, future control output and future control error. The Predictive controller is very practical because the controller can be easily applicable to a personal computer or a microprocessor. This study investigates through numerical simulations that hydraulic system with the predictive controller shows very good control performances.

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SVPWM을 이용한 PMLSM의 전류 제어 분석과 새로운 예측 전류 제어 (Analysis and Novel Predictive Control of current control for Permanent Magnet Linear Synchronous Motor using SVPWM)

  • 선정원;이진우;서진호;이영진;이권순
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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    • pp.236-238
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    • 2005
  • In this paper, we propose a new discrete-time predictive current controller for a PMLSM(permanent magnet linear synchronous motor). The main objectives of the current controllers are that the measured stator current is tracked the command current value accurately and the transient interval is shorten as much as possible, in order to obtain high-performance of ac drive system. The conventional predictive current controller is hard to implement in full digital current controller since a finite calculation time causes a delay between the current sensing time and the time that take to apply the voltage to motor. A new control strategy is the schema that gets the fast adaptation of transient current change, the fast transient response tracking. Moreover, the simulation results will be verified the improvements of Predictive controller and accuracy of the current controller.

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A semiparametric method to measure predictive accuracy of covariates for doubly censored survival outcomes

  • Han, Seungbong;Lee, JungBok
    • Communications for Statistical Applications and Methods
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    • 제23권4호
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    • pp.343-353
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    • 2016
  • In doubly-censored data, an originating event time and a terminating event time are interval-censored. In certain analyses of such data, a researcher might be interested in the elapsed time between the originating and terminating events as well as regression modeling with risk factors. Therefore, in this study, we introduce a model evaluation method to measure the predictive ability of a model based on negative predictive values. We use a semiparametric estimate of the predictive accuracy to provide a simple and flexible method for model evaluation of doubly-censored survival outcomes. Additionally, we used simulation studies and tested data from a prostate cancer trial to illustrate the practical advantages of our approach. We believe that this method could be widely used to build prediction models or nomograms.

예측제어기법을 이용한 PID 제어기 설계 (The PID Controller for Predictive control Algorithm)

  • 김양환;이정재;이정용;이장명
    • 제어로봇시스템학회논문지
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    • 제11권1호
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    • pp.19-26
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    • 2005
  • This paper is concerned with the design of a predictive PID controller which has similar features to the model-based predictive controller. A PID type control structure is defined, which includes prediction of the outputs and the recalculation of new set points using the future set point data. The optimal values of the PID gains are precalculated using the values of gains calculated from an unconstrained generalized predictive control algorithm. Simulation studies demonstrate the performance of the proposed controller and the results are compared with the conventional PID and fuzzy control algorithms.

비선형 예측제어 알고리즘을 이용한 회분식 중합 반응기의 온도제어 (Temperature control of a batch polymerization reactor using nonlinear predictive control algorithm)

  • 나상섭;노형준;이현구
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1000-1003
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    • 1996
  • Nonlinear unified predictive control(UPC) algorithm was applied to the temperature control of a batch polymerization reactor for polymethylmethacrylate(PMMA). Before the polymerization reaction is initiated, the parameters of the process model are determined by the recursive least squares(RLS) method. During the reaction, nonlinearities due to generation of heat of reaction and variation of heat transfer coefficients are predicted through the nonlinear model developed. These nonlinearities are added to the process output from the linear process model. And then, the predicted process output is used to calculate the control output sequence. The performance of nonlinear control algorithm was verified by simulation and compared with that of the linear unified predictive control algorithm. In the experiment of a batch PMMA polymerization, nonlinear unified predictive control was implemented to regulate the temperature of the reactor, and the validity of the nonlinear model was verified through the experimental results. The performance of the nonlinear controller turned out to be superior to that of the linear controller for tracking abrupt changes in setpoint.

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Safety Critical 시스템의 센서 결함 허용을 위한 Kalman Hybrid Redundancy 개발 (Development of Kalman Hybrid Redundancy for Sensor Fault-Tolerant of Safety Critical System)

  • 김만호;이석;이경창
    • 제어로봇시스템학회논문지
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    • 제14권11호
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    • pp.1180-1188
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    • 2008
  • As many systems depend on electronics, concern for fault tolerance is growing rapidly in the safety critical system such as intelligent vehicle. In order to make system fault tolerant, there has been a body of research mainly from aerospace field including predictive hybrid redundancy by Lee. Although the predictive hybrid redundancy has the fault tolerant mechanism to satisfy the fault tolerant requirement of safety crucial system such as x-by-wire system, it suffers form the variability of prediction performance according to the input feature of system. As an alternative to the prediction method of predictive hybrid redundancy for robust fault tolerant, Kalman prediction has attracted some attention because of its well-known and often-used with its structure called Kalman hybrid redundancy. In addition, several numerical simulation results are given where the Kalman hybrid redundancy outperforms with predictive smoothing voter.

A Novel Predictive Digital Controlled Sensorless PFC Converter under the Boundary Conduction Mode

  • Wang, Jizhe;Maruta, Hidenori;Matsunaga, Motoshi;Kurokawa, Fujio
    • Journal of Power Electronics
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    • 제17권1호
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    • pp.1-10
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    • 2017
  • This paper presents a novel predictive digital control method for boundary conduction mode PFC converters without the need for detecting the inductor current. In the proposed method, the inductor current is predicted by analytical equations instead of being detected by a sensing-resistor. The predicted zero-crossing point of the inductor current is determined by the values of the input voltage, output voltage and predicted inductor current. Importantly, the prediction of zero-crossing point is achieved in just a single switching cycle. Therefore, the errors in predictive calculation caused by parameter variations can be compensated. The prediction of the zero-crossing point with the proposed method has been shown to have good accuracy. The proposed method also shows high stability towards variations in both the inductance and output power. Experimental results demonstrate the effectiveness of the proposed predictive digital control method for PFC converters.

직류(直流) 전동기(電動機)를 위한 디지탈 P.I.D 예측(豫測) 보상(報償) 제어기(制御器) (P.I.D Predictive Controllers for The Various Types of D.C Drives)

  • 김윤호;윤병도;양원영;조용현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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    • pp.278-282
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    • 1989
  • A Digital P.I.D Predictive Controller is applied to the various types of D.C drives. The system with predictive controllers is compared to the system with conventional P.I.D controllers. The effect of the predictive control for the practical applications are investigated. The stability of the system with predictive controllers is also studied.

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