• Title, Summary, Keyword: System Control

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Hydraulic Control System Using a Feedback Linearization Controller and Disturbance Observer - Sensitivity of System Parameters -

  • Kim, Tae-hyung;Lee, Ill-yeong;Jang, Ji-seong
    • Journal of Drive and Control
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    • v.16 no.2
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    • pp.59-65
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    • 2019
  • Hydraulic systems have severe nonlinearity inherently compared to other systems like electric control systems. Hence, precise modeling and analysis of the hydraulic control systems are not easy. In this study, the control performance of a hydraulic control system with a feedback linearization compensator and a disturbance observer was analyzed through experiments and numerical simulations. This study mainly focuses on the quantitative investigation of sensitivity on system uncertainties in the hydraulic control system. First, the sensitivity on the system uncertainty of the hydraulic control system with a Feedback Linearization - State Feedback Controller (FL-SFC) was quantitatively analyzed. In addition, the efficacy of a disturbance observer coupled with the FL-SFC for the hydraulic control system was verified in terms of overcoming the control performances deterioration owing to system uncertainty.

Thermal Performance Evaluation of Solar Hot Water System according to Flow Rate Control (유량제어방식에 따른 태양열 급탕시스템의 열성능 평가)

  • Baek, Nam-Choon;Shin, U-Cheul
    • Journal of the Korean Solar Energy Society
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    • v.31 no.5
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    • pp.140-145
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    • 2011
  • In this study, the performance and behavior of solar heating system according to the system control scheme, variable flow control (proportional control) and constant flow control (on-off control) was carried out by experiment. The on-off control is used generally for solar thermal system by now. But the proportional control is used for the solar district heating system which is supplied the higher temperature of water than that of desired. The proportional control logic that pump speed is varied in an attempt to maintain a specified outlet temperature of solar heating system was developed and tested for the use widely for the small and medium solar thermal system. The results are as following. First, the proportional controller which is made here could be adopted the characteristics for setting temperature control. Second, the proportional control is better than the on-off control in the side of the performance of thermal stratification in storage tank. Third, the operating energy(electricity consumption by pump) of solar thermal system can be saved more than 60% using the proportional control comparing to the on-off control.

CONTROL CHARACTERISTICS OF SINGLE-SWITCH, THREE-PHASE BUCK RECTIFIERS

  • Song, Joong-Ho;Kim, Yong-Duck;Lee, Dong-Yun;Choy, Ick;Choi, Joo-Yeop
    • Proceedings of the KIPE Conference
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    • pp.658-662
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    • 1998
  • A pulse frequency modulation control method for single-switch three-phase buck rectifiers is comprehensively studied in this paper. The proposed pulse frequency control method leads the three-phase buck rectifier to high performance system that can draw the nearly sinusoidal imput-line currents. The simulated and experimental results demonstrate that the system provides low total harmonic distortion of the input-line currents, high-power factor, and good output voltage regulation.

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Development of an Electronic-Hydraulic Tilling-Depth Control System for Agricultural Tractors (농용(農用)트랙터의 전자유압식(電子油壓式) 경심(耕深) 제어(制御) 시스템 개발(開發))

  • Ryu, K.H.;Yoo, S.N.;Yun, Y.D.;Sakai, Sakai;Kim, Y.S.
    • Journal of Biosystems Engineering
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    • v.16 no.4
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    • pp.355-362
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    • 1991
  • The objective of this study was to develop an electronic-hydraulic depth control system. Simulation was carried out to investigate the responses of the control system, and indoor experiments were carried out to confirm the simulation results of the control system. Field experiments were carried out to compare the newly-developed electronic-hydraulic depth-control system with the existing mechanical-hydraulic position control system in terms of the performance of depth control. The electronic-hydraulic depth control system showed better performance than the existing mechanical-hydraulic hitch control system for the forward speeds of tractor less than 7 km/h. It is concluded that the new control system could be adapted to the existing tractors with slight modifications to the conventional mechanical-hydraulic hitch control systems.

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Electronic-Hydraulic Hitch Control System for Agricultural Tractor -Position Control- (트랙터의 전자유압식(電子油壓式) 히치제어 시스템에 관한 연구(硏究)(I) -위치제어(位置制御)-)

  • Yoo, S.N.;Ryu, K.H.;Park, J.G.
    • Journal of Biosystems Engineering
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    • v.14 no.3
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    • pp.168-180
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    • 1989
  • This study was attempted to develop the electronic-hydraulic hitch control system for position control of tractor plow and investigate the control performance of the system through experiments. Experiments were carried out to investigate the responses of the system to the step and sinusoidal inputs in position control. The effects of control mode, hydraulic flow rate, reference deadband, and proportional constant on control performance of the system were investigated. The following conclusions were derived from the study; 1. For the position control system operated on on-off control mode, positions of implement were controlled within ${\pm}0.73^{\circ}{\sim}{\pm}1.46^{\circ}$ in rockshaft angle to the reference position when the hydraulic flow rates were 5~15 l/min. For the position control system operated on PWM control mode, positions of implement were controlled within ${\pm}0.73^{\circ}$ to the reference position regardless of hydraulic flow rates. It means that the implement could be positioned more accurately to the reference position on PWM control mode than on on-off control mode. 2. As results of the frequency responses of the position control systems, no clear difference in control performance between on-off control and PWM control modes was found. As the hydraulic flow rates increased, the corner frequencies of amplitude attenuation and phase-angle change increased. It means that the control performance of the system could be improved as the hydraulic flow rate increases.

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Control Characteristics with Flow Rate Control Methods in Central Heating System (중앙난방시스템의 유량제어방식에 따른 제어특성 연구)

  • Song, Jae-Yeob;Ahn, Byung-Cheon
    • Transactions of the Korea Society of Geothermal Energy Engineers
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    • v.7 no.1
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    • pp.32-37
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    • 2011
  • In this study, control characteristics and energy performance with flow rate control methods were reviewed with the simulation. The heating system is classified such as fan coil unit and HVAC system currently used in buildings with valve control and pump inverter control. The simulation analysis program is made by TRNSYS ver. 15 with the actual data. As a result of this study, the central heating system with pump inverter control decreases electricity energy and reduces gas consumption. Inverter control method shows better performance in comparison with valve control one for energy saving.

An intelligent control system design for autonomous underwater vehicle (무인 수중운동체를 위한 지능제어시스템 설계)

  • Lee, Dong-Ik;Kwak, Dong-Hoon;Choi, Jung-Lak
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.3
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    • pp.227-237
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    • 1997
  • Autonomous Underwater Vehicles(AUVs) have become an important tool for various purposes in subsea: inspection, recovery, construction, etc., and the development of autonomous control system is luglay desirable- thete zffe many problems associated with designing the control system for AUV due to unknown underwater envimn-Tnent, the possibility of subsystem failures, and unpredictable changes in the dynamics of the vehicle. In this paper, an autonomous control system based on the intelligent control theory to enhance operation efficiency of the ALTV is presented. The control system has a hierarchical structure which consists of mission planning level, mission control level, navigation level, and execution level. The performance of the control system is investigated by computer simulation. The results show that the proposed control system can be applied successfully to the AUV in spite of the possibility of failures in the vehicle and the collision hazard in the sea environment.

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A Study on Active Control of the Radiated Duct Noise with Insufficient Number of Control Dources and Microphones (덕트 내부의 고차모드 수보다 적은 수의 제어음원과 마이크로폰을 이용한 덕트 방사소음 제어에 관한 연구)

  • 윤두병;김양한;정균양;조대승
    • Journal of KSNVE
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    • v.8 no.2
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    • pp.283-288
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    • 1998
  • If one wants to control the noise from a duct, then one must have sufficient number of sensors and actuators so that the control system is observable and controllable. A number of sensors and actuators for control of radiating noise from a duct have to be incorporated with the number of modes which one wants to control. These considerations motivated the present study that considers a control system which has less microphones and actuators than required. In this work, by theoretical analysis and numerical simulation, the control performance and robust reliability of such a kind of control system is investigated in terms of sound-field variables and control system variables. Then the possibility of implementation of the robust radiation power control system is verified by theoretical analysis and numerical simulation. In addition, the control performance of the control system is verified by experiment.

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Analysis on Flight Test Results of Reconfiguration Flight Control System (재형상 비행제어 시스템의 비행시험 결과 분석)

  • Min, Byoung-Mun;Kim, Seong-Pil;Kim, Bong-Ju;Kim, Eung-Tai;Tahk, Min-Jea
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.12
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    • pp.1244-1252
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    • 2008
  • This paper presents the analysis results obtained by the flight test of reconfiguration flight control system for an aircraft. The reconfiguration flight control system was designed by using control allocation scheme that automatically distributes the demanded control moments determined by control law to each actual control surface. In this paper, some control allocation algorithms for reconfiguration control of general aircraft with redundant control surfaces are summarized and their performance evaluation results through nonlinear simulation and Hardware-In-the-Loop-Simulation (HILS) test are shown. Also, Unmanned Aerial Vehicle (UAV) system adopted as a platform for the flight test of reconfiguration flight controller and the implementation procedure of reconfiguration flight controller into real-time UAV system were introduced. Finally, flight test results were analyzed.

Performance improvement of an active redundancy control system interfaced to a network management system (망관리 시스템에 접속되는 동적 이중화 제어 시스템의 성능 개선)

  • 박승창;장대익;오의교
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.4
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    • pp.11-17
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    • 1996
  • In the case of redundancy control performed by a netowrk management system, it can not be ignored some delay of control time and break of control by failure of the system. This paper proposed a new method to improve the performacne of a redundancy control system interfaced to the network management system. At first, it produced the modelling of the total system and analyzed the functional relation of reliability and failure rate for a transmission system having an one-to-one active redundancy structure controlled by itself. After describing the loss rate of transmission data and the time required for the redundancy control process of the network management system when a failure is occurred, it proposed the new redundancy method of complex system control mode as an effective redundancy control method to improve reliability of a redundancy control system. Finally, it proved the effect by comparing the new result to the previous result.

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