• Title/Summary/Keyword: active control device

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Detailed Design of an Active Rotor Blade for Reducing Helicopter Vibratory Loads

  • Natarajan, Balakumaran;Eun, Won-Jong;Shin, Sang-Joon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.236-241
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    • 2011
  • An active trailing-edge flap blade named as Seoul National University Flap (SNUF) blade is designed for reducing helicopter vibratory loads and the relevant aeroacoustic noise. Unlike the conventional rotor control, which is restricted to 1/rev frequency, an active control device like the present trailing-edge flap is capable of actuating each individual blade at higher harmonic frequencies i.e., higher harmonic control (HHC) of rotor. The proposed blade is a small scale blade and rotates at higher RPM. The flap actuation components are located inside the blade and additional structures are included for reinforcement. Initially, the blade cross-section design is determined. The aerodynamic loads are predicted using a comprehensive rotorcraft analysis code. The structural integrity of the active blade is verified using a stress-strain recovery analysis.

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Lifetime Seismic Risk of Offshore Structures with a Built-in Vibration Control Device (제진장치 설치 해양구조물의 생애주기 지진위험도)

  • Kim, Dong-Hyawn
    • Journal of Ocean Engineering and Technology
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    • v.24 no.5
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    • pp.48-54
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    • 2010
  • The analysis of the seismic risk of an offshore structure with a control device is presented. First, a probability density function was developed to represent seismic hazard, and seismic fragility under artificial earthquake conditions was determined. Fragility curves for an offshore structure with both passive and active control devices were determined. Displacement criteria were set to evaluate the performance of the structure. Based on numerical analysis, the seismic risk to the structure was considerably reduced when the structure had a seismic control device. The seismic risk to the actively controlled structure was decreased by 80% compared to the uncontrolled case. Reasonable performance evaluations of offshore structure with control devices can be conducted through risk analysis.

A Study on the Implementation of Automatic parking brake system using In-Vehicle network (차량 네트워크를 이용한 자동 주차브레이크 시스템 구현)

  • 문용선;문창현;이명복;정철호;최형윤
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.3
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    • pp.733-739
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    • 2004
  • As per the recent technology related to safety of vehicles, Active safety system is being developed in combination withthe technology of electronic system. For example, ABC(Active Body Control), ABS(Antilock Brake System), ACC(Adaptive Cruise Control) are representative of this system. This technology is based on an electronic system, and shares a lot of data through network-system invehicles. Therefore, the control-algorism and the practicable application are realized in this research in order that CAN, network system for vehicles can run the brake device, which is composed mechanically and hand-operated. Additionally the possibility is confirmed that this control-system can be compatible with the existing electronic system in vehicles.

Nonlinear Control of Cascade Hybrid Mass Dampers considering Stroke Saturation (스트로크 포화를 고려한 직렬 복합형 감쇠기의 비선형 제어)

  • 민경원;황성호;김성춘;호경찬;김인수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2000.10a
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    • pp.377-386
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    • 2000
  • Hybrid mass dampers consist of passive tuned mass dampers and active mass dampers. They have the advantage that passive tuned mass dampers are still operated even when active mass dampers are stopped by excessive disturbances or power failure. This paper begins first with the comparative analysis of tuned mass dampers, hybrid mass dampers, and active mass dampers. Next more detailed study is carried out on the hybrid mass dampers: cascade hybrid mass dampers (CHMD) and active tuned mass dampers (ATMD). CHMD is regarded as more reasonable device because of its lighter active mass than ATMD's. However CHMD can not neglect stroke saturation problem caused by the length limitation of active damper mass. We compensate the saturation problem with nonlinear restoring force. The restoring force is calculated based on the states and phases of active mass dampers and added to the control force. It is shown that the presented compensation method prevents CHMD from saturation behavior without apparent changes of control force and responses compared to those in case of not considering the saturation problem.

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Circulating Current Control in MMC-HVDC Considering Switching Device Current Capacity under Unbalanced Voltage Conditions (전압 불평형 조건에서 스위칭 소자의 전류용량을 고려한 MMC-HVDC 순환전류 제어기법)

  • Kim, Chun-Sung;Jung, Seung-Hwan;Hwang, Jung-Goo;Park, Seong-Mi;Park, Sung-Jun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.30 no.1
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    • pp.55-65
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    • 2016
  • This paper proposed a new control method which is capable of controlling circulating current considering current capacity of switching device. In the unbalanced voltage conditions, active power and reactive power have double line frequency. Thus, in order to provide active power without ripple, it is necessary to inject the negative sequence current components. However, when the negative current components is injected, it increases the total current flowing in the Arm, and in the Sub-module(SM) the current more than rated is impressed, which leads to destroy the system. Also, in impressing the circulating current reference of each arm, conventional control method impressed applicable $i_{dck}/3$ in the case of balanced voltage conditions. In the case of unbalanced conditions, as arm circulating current of three phase show difference due to the power impressed to each arm, reference of each arm is not identical. In this study, in the case of unbalanced voltage, within permitted current, the control method to decrease the ripple of active power is proposed, through circulating current control and current limitations. This control method has the advantage that calculates the maximum active power possible to generate capacity and impressed the current reference for that much. Also, in impressing circulating current reference, a new control method proposes to impress the reference from calculating active power of each phase. The proposed control method is verified through the simulation results, using the PSCAD/EMTDC.

Convenient Thermal Modeling for Loss Distribution method of 3-Level Active NPC Inverter using Newton's Law of cooling (Active NPC 인버터의 손실 분배 제어를 위한 뉴턴의 냉각법칙 기반의 간단한 열 모델링 기법)

  • Hyun, Seung-Wook;Lee, Jung-Hyo;Won, Chung-Yuen
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.9
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    • pp.71-80
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    • 2015
  • This paper proposes a convenient thermal modeling method for loss distribution control method of 3-level Active NPC(Neutral Point Clamped) inverter. In the drawback of conventional 3-level NPC, the generated losses can occur unbalance in each switching device, as a result, thermal utilization of designed system has been decreased. In order to compensate unbalanced losses, Active NPC inverter performed loss balancing control with thermal modeling during operation of each switching device. Therefore, this paper deals with a convenient thermal modeling method based on newton's law of cooling rather than conventional thermal modeling method. Both simulation and experimental results based on 10kW 3-level Active NPC inverter confirm the validity of the analysis performed in the study.

High-Speed Active Vibration Control System of Plate using TMS320C6713DSK (TMS320C6713DSK를 적용한 평판의 고속 능동 진동제어)

  • Choi, Hyeung-Sik;Her, Jae-Gwan;Seo, Hae-Yong
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.6
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    • pp.918-924
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    • 2009
  • This paper deals with the experimental assessment of the vibration suppression of the smart structures. First, we have presented the paper about the new high-speed active control system that we have developed using the DSP320C6713 microprocessor and a peripheral system composed of a data acquisition system, A/D and D/A converters, piezoelectric (PZT) actuator/sensors, and drivers using PA95. Since fast data processing is very important in the active vibration control of the structures, we utilized the fast processing DSP320C6713 microprocessor as a main processor to the controller and fast peripheral devices for fast control loop. To realize a fast active vibration control, we have analyzed and tested the processing time of the peripheral devices and provided the corresponding test results. Especially, we have focused on achieving the fast signal amplification of the PA95 device since it takes most of loop times of the control system. Finally, we performed numerous experiments of active vibration control of the aluminum plate to validate the superior performance of the developed control system based on previous mode tests of the plate.

Force Display Based on Simultaneous Actuation of Motors and Brakes

  • Kwon, Tae-Bae;Song, Jae-Bok
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1131-1135
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    • 2004
  • In the virtual environment, force feedback to the human operator makes virtual experiences more realistic. However, the force feedback using active actuators such as motors can make the system active and sometimes unstable. To ensure the safe operation and enhance the haptic feeling, stability should be guaranteed. Both motors and brakes are commonly used for haptic device. A brake can generate a torque only against its rotation, but it is intrinsically stable. Consequently, motors and brakes are complementing each other. In this research, a two degree-of-freedom (DOF) haptic device equipped with both motors and brakes has been developed to provide better haptic effects. Each DOF is actuated by a pair of motor and brake. Modeling of the environment and the control method are needed to utilize both actuators. For various haptic effects, contact with the virtual wall and representation of friction effect are extensively investigated in this paper. It is shown that the hybrid haptic system is more suited to some applications than the motor-based active haptic system.

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Distributed Power Saving Control System Using Mobile Agent Based Active Rules (이동에이전트 기반 능동규칙을 이용한 분산형 절전제어시스템)

  • Lee, Yonsik;Jang, Minseok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.5
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    • pp.153-159
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    • 2014
  • In this paper, we propose the Distributed Power Saving Control System that enables the active and intelligent control(on/off and/or dimming control) of the lightning device using sensors and mobile agents. The proposed system is effective for energy saving and induces cost reductions in design and development of power saving control system as adding remote-monitoring or controlling functions is easier with the application of a variety of active rules. Moreover, the system improves the effectiveness of the acquired sensing data by real-time event handling and device controlling using a mobile agent based sensor network middleware that regularize the contextual information or a user's emotion. The results of this paper present the potential applicability of the proposed distributed control system using mobile agent in various active sensor network applications.

Design and Implementation of the Device Independent RFID Middleware Component for the Next Generation Port-Logistics (차세대 항만물류를 위한 장치 독립형 RFID 미들웨어 구성요소의 설계 및 구현)

  • Jang, Su-Wan;Kim, Jong-Deok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.1
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    • pp.124-130
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    • 2007
  • RFID technology is considered as a promising solution to increase efficiency of port logistics. Especially active RFID technology, such as e-Seal for container security, is receiving attention nowadays. If active RFID system is combined with passive RFID and legacy bar-code system overall efficiency of port logistics can be improved However, due to the device dependent control interface of RFID readers, there are many difficulties in making active-passive combined RFID system environment. In this paper, we introduce Smart Reader Interface (SRI) system, which provides a device independent RFID reader interrace to control different kinds of RFID readers by hiding device dependent control interface through adapter architecture which is similar to device driver of conventional operating systems. The key design objectives of SRI are the followings; conformance to the related standard. efficiency in processing, easy addition of an adapter for a new RFID reader. Actually, the implemented SRI system can support various kinds of commercial RFID readers, and through the test carried out not only in laboratory but also in the container terminal in the GwangYang Port, its practicality is verified.