• Title, Summary, Keyword: Rate Control

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PID control of left ventricular assist device (PID 제어기를 이용한 좌심실보조장치의 제어)

  • Jeong, Seong-Taek;Kim, Hun-Mo;Kim, Sang-Hyeon
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.3
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    • pp.315-320
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    • 1998
  • In this paper, we present the PID control method for the controlling flow rate of highly complicated nonlinear Left Ventricular Assist Device(LVAD) with pneumatically driven mock circulatory system. Beat Rate (BR), Systole-Diastole Rate (SDR) and flow rate are used as the main variables of the LVAD system. System modeling is completed using the neural network with input variables (BR, SDR, their derivatives, actual flow) and an output valiable(actual flow). Then, as the basis of this model, we perform the simulation of PID control to predict the performance and tendency of the system and control the flow rate of LVAD system using the PID controller. The ability and effectiveness of identifying and controlling a LVAD system using the proposed algorithm will be demonstrated through computer simulation and experiments.

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Lateral Stability Control of Electric Vehicle Based On Disturbance Accommodating Kalman Filter using the Integration of Single Antenna GPS Receiver and Yaw Rate Sensor

  • Nguyen, Binh-Minh;Wang, Yafei;Fujimoto, Hiroshi;Hori, Yoichi
    • Journal of Electrical Engineering and Technology
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    • v.8 no.4
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    • pp.899-910
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    • 2013
  • This paper presents a novel lateral stability control system for electric vehicle based on sideslip angle estimation through Kalman filter using the integration of a single antenna GPS receiver and yaw rate sensor. Using multi-rate measurements including yaw rate and course angle, time-varying parameters disappear from the measurement equation of the proposed Kalman filter. Accurate sideslip angle estimation is achieved by treating the combination of model uncertainties and external disturbances as extended states. Active front steering and direct yaw moment are integrated to manipulate sideslip angle and yaw rate of the vehicle. Instead of decoupling control design method, a new control scheme, "two-input two-output controller", is proposed. The extended states are utilized for disturbance rejection that improves the robustness of lateral stability control system. The effectiveness of the proposed methods is verified by computer simulations and experiments.

Oil Flow Distribution Control of Engine Lubrication System Using Orifice Component (오리피스를 이용한 엔진 윤활시스템 유량분배 제어)

  • Yun Jeong-Eui
    • Tribology and Lubricants
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    • v.22 no.1
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    • pp.47-52
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    • 2006
  • It is very important to control pressure and flow rate distribution on each component of engine lubrication network. Sometimes many kinds of orifice are used to control flow rate in the hydraulic lubrication field. In this study orifices were adopted on the lubrication network to control oil flow rate distribution. And unsteady transient flow network analysis was carried out to find out the effects of orifices on the engine oil circuit system.

System Identification of Internet transmission rate control factors

  • Yoo, Sung-Goo;Kim, Young-Seok;Chong, Kil-To
    • 제어로봇시스템학회:학술대회논문집
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    • pp.652-657
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    • 2004
  • As the real-time multimedia applications through Internet increase, the bandwidth available to TCP connections is oppressed by the UDP traffic, result in the performance of overall system is extremely deteriorated. Therefore, developing a new transmission protocol is necessary. The TCP-friendly algorithm is an example meeting this necessity. The TCP-friendly (TFRC) is an UDP-based protocol that controls the transmission rate based on the available round transmission time (RTT) and the packet loss rate (PLR). In the data transmission processing, transmission rate is determined based on the conditions of the previous transmission period. If the one-step ahead predicted values of the control factors are available, the performance will be improved significantly. This paper proposes a prediction model of transmission rate control factors that will be used for the transmission rate control, which improves the performance of the networks. The model developed through this research is predicting one-step ahead variables of RTT and PLR. A multiplayer perceptron neural network is used as the prediction model and Levenberg-Marquardt algorithm is used for the training. The values of RTT and PLR were collected using TFRC protocol in the real system. The obtained prediction model is validated using new data set and the results show that the obtained model predicts the factors accurately.

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A Consistent Quality Bit Rate Control for the Line-Based Compression

  • Ham, Jung-Sik;Kim, Ho-Young;Lee, Seong-Won
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.5
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    • pp.310-318
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    • 2016
  • Emerging technologies such as the Internet of Things (IoT) and the Advanced Driver Assistant System (ADAS) often have image transmission functions with tough constraints, like low power and/or low delay, which require that they adopt line-based, low memory compression methods instead of existing frame-based image compression standards. Bit rate control in the conventional frame-based compression systems requires a lot of hardware resources when the scope of handled data falls at the frame level. On the other hand, attempts to reduce the heavy hardware resource requirement by focusing on line-level processing yield uneven image quality through the frame. In this paper, we propose a bit rate control that maintains consistency in image quality through the frame and improves the legibility of text regions. To find the line characteristics, the proposed bit rate control tests each line for ease of compression and the existence of text. Experiments on the proposed bit rate control show peak signal-to-noise ratios (PSNRs) similar to those of conventional bit rate controls, but with the use of significantly fewer hardware resources.

Wave overtopping control by the use of ecosystem control structures (생태계 제어구조물의 월파제어 특성)

  • 김현주;류청로
    • Journal of Ocean Engineering and Technology
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    • v.11 no.2
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    • pp.122-130
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    • 1997
  • Coastal diaster induced by waves and countermeasures were investigated in the viewpoint of reduction of overtopping rate with enviroment in fishing port. The reduction method of wave overtopping rate using ecosystem control structures was proposed and studied on the efficiency by hydraulic and numerical experiments. The estimation models on wave overtopping rate was proposed after comparing previous models with dimensional analysis and experimental results. Control function o fwave overtopping by use of ecosystem controlstructures was simulated and discussed with combining wave shoaling-dissipation-breaking deformation model around ecosystem control structures and newly proposed calculation model for wave overtopping rate. Feasiblilty of ecosystem control structures could be confirmed for reduction of wave overtopping and fisheries-based multipurpose development of coastal zone.

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Study on Vertical Dynamics Compensation for Wobbling Effect Mitigation of Electrostatically Levitated Gyroscope

  • Lee, Jongmin;Song, Hyungmin;Sung, Sangkyung;Kim, Chang Joo;Lee, Sangwoo
    • International Journal of Aeronautical and Space Sciences
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    • v.15 no.3
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    • pp.293-301
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    • 2014
  • We present a study of vertical dynamics control of an electrostatically levitated gyro-accelerometer considering the wobbling effect and propose a tilt stabilization method with newly introduced control electrodes. Typically, a rotor in a vacuum rotates at high velocity, which may create a drift rate and lead to displacement instability due to the tilt angle of the rotor. To analyze this, first we set up a vertical dynamic equation and determined simulation results regarding displacement control. After deriving an equation for drift dynamics, we analyzed the drift rate of the rotor and the wobbling effect for displacement control quantitatively. Then, we designed new sub-electrodes for moment control that will decrease the drift amplitude of wobbling dynamics. Finally, a simulation study demonstrated that the vertical displacement control with the wobbling compensation electrodes mitigated the rotor's drift rate, showing the effectiveness of the newly proposed control electrodes.

Delay-based Rate Control for Multimedia Streaming in the Internet (인터넷에서 멀티미디어 스트리밍을 위한 지연 시간 기반 전송률 제어)

  • Song Yong-Hon;Kim Nam-Yun;Lee Bong-Gyou
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.9B
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    • pp.829-837
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    • 2006
  • Due to the internet network congestion, packets may be dropped or delayed at routers. This phenomenon degrades the quality of streaming applications that require high QoS requirements. The proposed algorithm in this paper, called DBRC(Delay-Based Rate Control), tries to cause router queue occupancy to reach a steady state or equilibrium by throttling the transmission rate of the multimedia traffics when network delays tend to increase and also probing for more bandwidth when network delays tend to decrease. Simulation results show that the proposed algorithm provides smooth transmission rate, nearly constant delay and low packet loss rates, compared with TFRC(TCP Friendly Rate Control) that is one of dominant multimedia congestion control algorithms.

The Experimental Study of the Heat Flux and Energy Consumption on Variable Flow Rate for Secondary Side of DHS (지역난방 2차측 유량변화가 내부 열유속 및 에너지소비량에 미치는 영향에 관한 실험적 연구)

  • Hong, Seong-Ki;Cho, Sung-Hwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.5
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    • pp.247-253
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    • 2015
  • The presented work demonstrates the effects of flow rate on the secondary side of DHS (District Heating System). Increasing flow rate at the secondary side of DHS decreases energy consumption and time to reach the set-point of the heated room while increasing heat flux on the floor in the heating space. When flow rate increases, the overall heat transfer rate of radiant floor also increases. However, the results also show overall heat transfer rateto not increased linearly and thus the existence of an optimal flow rate for the secondary side of DHS. Control of the radiant floor with hot water may be more effectively accomplished with a combined control strategy that includes heat flux and a temperature set-point. This experimental analysis has been performed using a lab-scaled DHS pilot plant located at Jeonju University in Korea.

A method for feeding flow rate control by measuring weight (무게 측정에 의한 원료 정량 투입 제어 방법)

  • 권오정;황일영;이광순
    • 제어로봇시스템학회:학술대회논문집
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    • pp.937-940
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    • 1992
  • A cost-saving feeding rate contro method for a batch reaction process is proposed by reconfigurating the flow rate control loop where the feeding rate is estimated by differentiating weight measurement. While the existing control methods require either a flow rate measurement device or a flow rate estimator, the proposed method is devised not to require neither of these facilities by directly controlling the tank weight with a time-varying set point. Experimental evaluation in a pilot-scale unit shows that the proposed method can significantly reduce the actuator hunting of the existing method where the flow rate is estimated by differentiating the weight measurement.

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