• Title/Summary/Keyword: Feed forward

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Adaptive Control of Permanent Magnet Linear Synchronous Motor using Wavelet Transform

  • Lee, June;Lee, Jin-Woo;;Lee, Young-Jin;Lee, Kwon-Soon
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.63-67
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    • 2004
  • The problem is improving the positioning precision of a permanent magnet linear synchronous motor (PMLSM). Thus, this paper presents the design and realization of an adaptive dither to reduce the force ripple in PMLSM. A composite control structure is used, consisting of three components: a simple feed-forward component, a PID feedback component and an adaptive feed-forward compensator (AFC). Especially adaptive feed-forward component cancel out detent force using wavelet transformation. Computer simulation results verify the effectiveness of the proposed scheme for high precision motion trajectory tracking using the PMLSM

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Design and Fabrication of Linear Power Amplifier for IMT-2000 Using FeedForward Method Combined Predistortion Method (전치왜곡 방식이 결합된 FeedForward 방식을 이용한 IMT-2000용 선형 전력 증폭기의 설계 및 제작)

  • 김경호;정재호;김성민;최현철
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.341-344
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    • 2000
  • Advanced FeedForward method use Predistortion method and FeedForward method simultaneously. This method better than original Feedforward method in linearity and supply smaller power to pre-power amplifier than different methods, and then it has higher power efficiency and better linearity than original Feedforward method. A linear power amplifier using Advanced feedforward method is designed and fabricated for IMT-2000 transmission system (2110㎒ -2170M㎓). This amplifier's power gain is about 40㏈ and it's 3-rd IMD(Intermodulation distortion) are smaller than about -55㏈c(@ 10MHz).

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Design of a Surface-Mounted PMSM Current Controller Using Uncertainty Estimation with a PI Observer (PI 관측기의 불확실성 추정을 이용한 표면부착형 영구자석 동기기의 전류 제어기 설계)

  • Kim, In-Hyuk;Choi, Dae-Sik;Son, Young-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.5
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    • pp.1011-1016
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    • 2011
  • This paper presents a robust current controller for a surface-mounted permanent magnet synchronous motor(SPMSM) by using a PI observer. The decoupling PI(proportional-integral) controller combined with an additional feed-forward compensation has been used for the current controller. The classical feed-forward compensation using velocity information and system parameters is not expected to achieve a robust performance against parameter uncertainties. This paper has adopted a PI observer for the feed-forward compensation to cope with parameter uncertainties without using velocity information. A simple PI observer has been designed to compensate the disturbances that represent velocity coupled terms and parameter uncertainties. Experimental results as well as computer simulations with 630W SPMSM confirm that the proposed approach can deal with the effects of the disturbance and improve the control performance.

Dynamic Characteristics Control of a Step-down Chopper Using Load current Feed-forward Compensator (부하전류 전향보상기를 이용한 강압쵸퍼의 동특성 제어)

  • Chung, Chun-Byung;Chun, Ji-Yong;Jeon, Kee-Young;Han, Kyung-Hee
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.05a
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    • pp.66-69
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    • 2008
  • In this paper, The author present a load current feed-forward compensator by method that improve voltage controller of Step-down Chopper to get stable output voltage to sudden change of load current. To confirm the characteristicsof a presented load current feed -forward compensator compared each transfer function of whole system that load current feed-forward compensator is added with transfer function of whole system that existent voltage controller is included using Mason gains formula in Root locus and Bode diagram. As a result the pole of system is improved, extreme point of the wave and system improves, and size of peak value and phase margin of break frequency in resonance frequency confirmed that is good. Therefore, presented control technique could confirm that reduce influence by perturbation and improves stationary state and dynamic characteristics in output of Step-down Chopper.

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Position Control of Servo Systems Using Feed-Forward Friction Compensation (피드포워드 마찰 보상을 이용한 서보 시스템의 위치 제어)

  • Park, Min-Gyu;Kim, Han-Me;Shin, Jong-Min;Kim, Jong-Shik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.5
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    • pp.508-513
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    • 2009
  • Friction is an important factor for precise position tracking control of servo systems. Servo systems with highly nonlinear friction are sensitive to the variation of operating condition. To overcome this problem, we use the LuGre friction model which can consider dynamic characteristics of friction. The LuGre friction model is used as a feed-forward compensator to improve tracking performance of servo systems. The parameters of the LuGre friction model are identified through experiments. The experimental result shows that the tracking performance of servo systems with higherly nonlinear friction can be improved by using feed-forward friction compensation.

Device Discovery using Feed Forward Neural Network in Mobile P2P Environment

  • Kwon, Ki-Hyeon;Byun, Hyung-Gi;Kim, Nam-Yong;Kim, Sang-Choon;Lee, Hyung-Bong
    • Journal of Digital Contents Society
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    • v.8 no.3
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    • pp.393-401
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    • 2007
  • P2P systems have gained a lot of research interests and popularity over the years and have the capability to unleash and distribute awesome amounts of computing power, storage and bandwidths currently languishing - often underutilized - within corporate enterprises and every Internet connected home in the world. Since there is no central control over resources or devices and no before hand information about the resources or devices, device discovery remains a substantial problem in P2P environment. In this paper, we cover some of the current solutions to this problem and then propose our feed forward neural network (FFNN) based solution for device discovery in mobile P2P environment. We implements feed forward neural network (FFNN) trained with back propagation (BP) algorithm for device discovery and show, how large computation task can be distributed among such devices using agent technology. It also shows the possibility to use our architecture in home networking where devices have less storage capacity.

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A Large-Signal Analysis of a Ring Oscillator with Feed-Forward and Negative Skewed Delay (부 스큐 지연 방식과 피드포워드 방식을 사용한 링 발진기의 대신호 해석)

  • Lee, Jeong-Kwang;Yi, Soon-Jai;Jeong, Hang-Geun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.7
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    • pp.1332-1339
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    • 2010
  • This paper presents a large signal analysis of ring-type oscillators with feed forward and negative skewed delay scheme. The analysis yields the frequency increase factor due to two schemes. The large signal analysis is needed, because small signal model is limited to the initial stage of oscillation[1]. For verification of the frequency increase factor, simulation were done under the same conditions for the two different types of ring oscillators, i.e., with and without feed forward and negative skewed delay scheme. Simulation results are in good agreement with predictions based on analysis.

Implementation of Fuzzy Self-Tuning PID and Feed-Forward Design for High-Performance Motion Control System

  • Thinh, Ngo Ha Quang;Kim, Won-Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.14 no.2
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    • pp.136-144
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    • 2014
  • The existing conventional motion controller does not perform well in the presence of nonlinear properties, uncertain factors, and servo lag phenomena of industrial actuators. Hence, a feasible and effective fuzzy self-tuning proportional integral derivative (PID) and feed-forward control scheme is introduced to overcome these problems. In this design, a fuzzy tuner is used to tune the PID parameters resulting in the rejection of the disturbance, which achieves better performance. Then, both velocity and acceleration feed-forward units are added to considerably reduce the tracking error due to servo lag. To verify the capability and effectiveness of the proposed control scheme, the hardware configuration includes digital signal processing (DSP) which plays the main role, dual-port RAM (DPRAM) to guarantee rapid and reliable communication with the host, field-programmable gate array (FPGA) to handle the task of the address decoder and receive the feed-back encoder signal, and several peripheral logic circuits. The results from the experiments show that the proposed motion controller has a smooth profile, with high tracking precision and real-time performance, which are applicable in various manufacturing fields.

Motion predictive control for DPS using predicted drifted ship position based on deep learning and replay buffer

  • Lee, Daesoo;Lee, Seung Jae
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.768-783
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    • 2020
  • Typically, a Dynamic Positioning System (DPS) uses a PID feed-back system, and it often adopts a wind feed-forward system because of its easier implementation than a feed-forward system based on current or wave. But, because a ship's drifting motion is caused by wind, current, and wave drift loads, all three environmental loads should be considered. In this study, a motion predictive control for the PID feedback system of the DPS is proposed, which considers the three environmental loads by utilizing predicted drifted ship positions in the future since it contains information about the three environmental loads from the moment to the future. The prediction accuracy for the future drifted ship position is ensured by adopting deep learning algorithms and a replay buffer. Finally, it is shown that the proposed motion predictive system results in better station-keeping performance than the wind feed-forward system.

Feed forward Differential Architecture of Analog Parallel Processing Circuits for Analog PRML Decoder (아날로그 PRML 디코더를 위한 아날로그 병렬처리 회로의 전향 차동 구조)

  • Sah, Maheshwar Pd.;Yang, Chang-Ju;Kim, Hyong-Suk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.8
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    • pp.1489-1496
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    • 2010
  • A feed forward differential architecture of analog PRML decoder is investigated to implement on analog parallel processing circuits. The conventional PRML decoder performs the trellis processing with the implementation of single stage in digital and its repeated use. The analog parallel processing-based PRML comes from the idea that the decoding of PRML is done mainly with the information of the first several number of stages. Shortening the trellis processing stages but implementing it with analog parallel circuits, several benefits including higher speed, no memory requirement and no A/D converter requirement are obtained. Most of the conventional analog parallel processing-based PRML decoders are differential architecture with the feedback of the previous decoded data. The architecture used in this paper is without feedback, where error metric accumulation is allowed to start from all the states of the decoding stage, which enables to be decoded without feedback. The circuit of the proposed architecture is simpler than that of the conventional analog parallel processing structure with the similar decoding performance. Characteristics of the feed forward differential architecture are investigated through various simulation studies.