• Title/Summary/Keyword: Feedforward compensation

Search Result 123, Processing Time 0.043 seconds

A Simultaneous Experimental Disturbances Identification of Gyro Stabilized 2-Axes Gimbal System for Disturbance Feedforward Compensation Control (2-축 자이로 안정화 김발 시스템의 외란보상 앞먹임 제어를 위한 실험적 2-축 외란 동시 식별)

  • Yeo, Sung Min;Kang, Min Sig
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.21 no.4
    • /
    • pp.508-519
    • /
    • 2018
  • This paper concerns on stabilization control of a gyro-stabilized 2-axes gimbal system which is mounted on a moving vehicles such as automobiles, armored vehicles, ships, flying vehicles, etc. A target image acquisition system is attached on the inner gimbal, and the gimbal systems are required to retain high stabilization accuracy in the absolute coordinate in order to provide fine target image while vehicle is moving. The stabilization control performance is hardly depended upon disturbance rejection ability of control, and disturbance feedforward compensation is effective because feedforward compensation reduce the amount of disturbance before the disturbance disturbs the systems. This paper suggests an experimental method which can estimate system parameters and disturbance torques by using 3-axes accelerometer mounted on the inner gimbal. Furthermore, a simple disturbance identification method which can be applied to any slanted base conditions has been suggested to identify mass unbalance vector and friction torques of each gimbal simultaneously. By using the estimated parameters, a feedforward compensation has been applied to the gyro-stabilized 2-axes gimbal system. The experimental results showed that the feedforward compensation based on the identification method suggested is effective to improve stabilization performances.

A Feedforward Compensation Method for 120Hz Output Voltage Ripple Reduction of LLC Resonant Converter (LLC 공진 컨버터의 120Hz 출력전압 리플 저감을 위한 전향보상 방법)

  • Yoon, Jong-Tae;Lee, Kui-Jun
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.26 no.1
    • /
    • pp.46-52
    • /
    • 2021
  • This study proposes a feedforward compensation control method to reduce 120 Hz output voltage ripple in a single-phase AC/DC rectifier system composed of PFC and LLC resonant converters. The proposed method compensates for the voltage ripple of the DC-link by using the AC input and DC output power difference, and then reduces the final output voltage ripple component of 120 Hz through feedforward compensation based on the linearized frequency gain curve of the LLC resonant converter. Through simulation and experimental results, the validity of the ripple reduction performance was verified by comparing the conventional PI controller and the proposed feedforward compensation method.

Feedforward Compensation Method of Output Voltage with 3Phase AC/DC PWM Converter on DC Distribution System for Improved Response (응답성 향상을 위한 직류배전용 3상 AC/DC PWM 컨버터 출력전압 전향보상 기법)

  • Choi, Hyeong-Jun;Lee, Chun-Bok;Hong, Seok-Jin;Hyun, Seung-Wook;Won, Chung-Yuen
    • Proceedings of the KIPE Conference
    • /
    • 2015.07a
    • /
    • pp.516-517
    • /
    • 2015
  • This paper proposes the feedforward compensation method of output voltage with 3phase AC/DC PWM converter on DC distribution system for improved response. AC/DC PWM converter on DC distribution is required power supply of high quality because of renewable energy sources and load links. In general, Feedforward compensation method of 3phase AC/DC PWM converter receives the sensor input to the output current, load power. Resulting, error of the sensing values and communication cause time delay. Therefore, Feedforward compensation method through only the output voltage is proposed in this paper. The feedforward compensation method through only the output voltage can be applied to the two-level AC/DC PWM converters, as well as multi-level converter or inverter.

  • PDF

Compensation of torque ripple of brushless DC motor using feedforward method (Feedforwad 방법을 이용한 BLDC 모터의 토크리플 보상)

  • 장호연;박기철;장평훈
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.736-739
    • /
    • 1997
  • In recent years, there has been a renewed interest in the BLDC motor as a research subject. In this paper we inspect sources of the torque ripple, which is one of the elements causing performance depreciation of BLDC motors. Based on the inspected sources of the torque ripple, feedforward compensation methods are proposed to reduce the size of torque ripple. The effectiveness of the proposed methods is verified with experiments.

  • PDF

Speed Control of an Induction Motor using Acceleration Feedforward Compensation (가속도 전향보상을 이용한 유도전동기의 속도제어)

  • Kim, Sang-Hoon;Lee, Jae-Wang
    • Journal of Industrial Technology
    • /
    • v.20 no.B
    • /
    • pp.175-182
    • /
    • 2000
  • In this paper, a novel speed control strategy using an acceleration feedforward compensation by the estimation of the system inertia is proposed. With the proposed method, the enhanced speed control performance can be achieved and the speed response against the disturbance torque can be improved for the vector-controller induction motor drive systems in which the bandwidth of the speed controller cannot be made large enough. The experimental results confirm the validity of the proposed strategy.

  • PDF

Decoupling Control of Three-tank Liquid Level Systems Based on Feedforward Compensation (Feedforward 보상에 근거한 3개의 탱크 액체 레벨 시스템의 통제 분리)

  • Shi, Xue-Wen
    • 전자공학회논문지 IE
    • /
    • v.45 no.3
    • /
    • pp.36-41
    • /
    • 2008
  • By considering decoupling between loops as a kind of measurable disturbance, a steady-state decoupling method based on feedforward compensation is proposed for a three-tank liquid level system often encountered in practical process control. In addition, the three-tank liquid level system's dynamic model with structure of two-input and two-output is presented according to its working principle. Finally simulation experiments given in C++Builder language demonstrate the effectiveness of the proposed method.

A Design of Sliding Mode Observer for SISO Linear Systems (단일 입.출력 선형시스템에 대한 슬라이딩 모드 관측기 설계)

  • 문형장;권성하;박승규;정은태
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.24-24
    • /
    • 2000
  • This paper proposes a design method of sliding mode observer for SISO linear systems with a disturbance input. We first construct an observer with a constant gain matrix, a feedforward injection map and an external feedforward compensation signal input. Using the second Lyapunov method, we present a sufficient condition for the existence of sliding mode observer. The proposed observer guarantees that the state error trajectories enter a certain region in finite time and remain inside thereafter.

  • PDF

Voltage Feedforward Control with Time-Delay Compensation for Grid-Connected Converters

  • Yang, Shude;Tong, Xiangqian
    • Journal of Power Electronics
    • /
    • v.16 no.5
    • /
    • pp.1833-1842
    • /
    • 2016
  • In grid-connected converter control, grid voltage feedforward is usually introduced to suppress the influence of grid voltage distortion on the converter's grid-side AC current. However, owing to the time-delay in control systems, the suppression effect of the grid voltage distortion is seriously affected. In this paper, the positive effects of the grid voltage feedforward control are analyzed in detail, and the time-delay caused by the low-pass filter (LPF) in the voltage filtering circuits and digital control are summarized. In order to reduce the time-delay effect on the performance of the feedforward control, a voltage feedforward control strategy with time-delay compensation is proposed, in which, a leading correction of the feedforward voltage is used. The optimal leading step used in this strategy is derived from analyzing the phase-frequency characteristics of a LPF and the implementation of digital control. By using the optimal leading step, the delay in the feedforward path can be further counteracted so that the performance of the feedforward control in terms of suppressing the influence of grid voltage distortion on the converter output current can be improved. The validity of the proposed method is verified through simulation and experiment results.

The comparison of the Feedforward compensation and Computed-Torque control schemes (Computed-Torque 제어와 Feedforward 역학 보상 제어 방법의 비교 평가)

  • Chung, Yong-Oug;Bae, Jun-Kyung;Park, Chong-Kuk
    • Proceedings of the KIEE Conference
    • /
    • 1988.11a
    • /
    • pp.68-71
    • /
    • 1988
  • The purpose of this paper is to compare with the simulated results of two control algorithms control algorithm in the real time, based upon the model. These control schemes are "Computed-torque" and "Feedforward-Dynamics compensation", and have been simulated on the CMU DD Arm II.

  • PDF

An Active Feedforward Compensation for a Current Harmonics Reduction in Three-phase Grid-connected Inverters (3상 계통 연계형 인버터에서의 전류 고조파 감쇄를 위한 능동형 피드포워드 보상 기법)

  • Park, Byong-Jun;Kim, Rae-Young;Choi, Ki-Young
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.19 no.1
    • /
    • pp.1-7
    • /
    • 2014
  • This paper proposes a current harmonic compensation method for the grid-connected inverter, especially caused by the grid impedance. Grid impedance causes low order harmonics in the grid current and deteriorates power quality. This paper analyzes the negative impact of the grid impedance, and proposes an active feedforward compensation method. Proposing method verified through simulation and experiment with 3-phase 1.5kW voltage source inverter prototype.