• Title/Summary/Keyword: Hybrid system

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Robust Hybrid Control System (강인 복합제어 시스템)

  • 박규식;정형조;오주원;이인원
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.442-449
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    • 2003
  • This paper presents a robust hybrid control system for seismic response control of a cable-stayed bridge. Because multiple control devices are operating, a hybrid control system could alleviate some of restirctions and limitations that exist when each system is acting alone. A LQG algorithm with on-off control scheme, H$_2$ and H$_{\infty}$ control algorithms with various frequency weighting filters are used to improve the controller robustness of the active control part in the hybrid control system. The numerital simulation results show that control performances of robust hybrid control systems are similar to those of the hybrid control system with LQG algorithm. Furthermore, it is verified that robust hybrid control systems are more robust than the hybrid control system with LQG algorithm and there are no signs of instabilities in the $\pm$5% stiffness matrix perturbed system. Therefore, the proposed hybrid control system have a good robustness for stiffness matrix perturbation without loss of control effectiveness.

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Development of Kalman Hybrid Redundancy for Sensor Fault-Tolerant of Safety Critical System (Safety Critical 시스템의 센서 결함 허용을 위한 Kalman Hybrid Redundancy 개발)

  • Kim, Man-Ho;Lee, Suk;Lee, Kyung-Chang
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.11
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    • pp.1180-1188
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    • 2008
  • As many systems depend on electronics, concern for fault tolerance is growing rapidly in the safety critical system such as intelligent vehicle. In order to make system fault tolerant, there has been a body of research mainly from aerospace field including predictive hybrid redundancy by Lee. Although the predictive hybrid redundancy has the fault tolerant mechanism to satisfy the fault tolerant requirement of safety crucial system such as x-by-wire system, it suffers form the variability of prediction performance according to the input feature of system. As an alternative to the prediction method of predictive hybrid redundancy for robust fault tolerant, Kalman prediction has attracted some attention because of its well-known and often-used with its structure called Kalman hybrid redundancy. In addition, several numerical simulation results are given where the Kalman hybrid redundancy outperforms with predictive smoothing voter.

A Study on the Performance Evaluation of the Hybrid Ventilation System for Small Apartment Houses (소형 공동주택의 하이브리드 환기시스템 성능실험 연구)

  • Chun, Chu-Young;Kim, Gil-Tae;Lee, Jong-Sung;Kim, Sang-Hee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.10
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    • pp.696-701
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    • 2008
  • From Feb. 2006, the ventilating systems with air exchange rate of over 0.7times/hour are installed at the apartment houses (over 100 units). Installation cost and maintenance cost are very important factors for ventilating system because consumers have to pay the expenses of that system. Especially small apartment needs more considerations because small apartment is comparatively the economically weak part. The purpose of this study is to the performance evaluation of the hybrid ventilation system for small apartment houses. Hybrid system 1 consists of natural ventilation system and duct type exhaust diffusers. Hybrid system 2 has natural ventilation system and toilet exhaust system with static pressure fan. Infiltration of test apartment houses with ventilation system is under 0.1 times/hour. Mean air age of hybrid system 1 is 1.52 hours and hybrid system 2 is 1.42 hours. Mean ventilation effectiveness of hybrid system 2(93%) is higher than that of hybrid system 1(81%).

Error Probability of a Hybrid DS/SFH Spread-Spectrum System under Tone Jamming (Tone 신호방해 하에서의 DS/SFH 복합 확산대역 시스템의 비트오율)

  • 유병석;이재홍;이상철
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.5
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    • pp.645-655
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    • 1990
  • A hybrid DS/SFH spread spectrum system is used to achieve a larger gain in some applications. The probability of error for a hybrid DS/SFH(direct sequence/slow frequency hopped) spread-spectrum system is calculated over a channel which suffers from multiple-tone jamming and additive white Gaussian noise. BPSK(binary phase shift keying) is considered as modulation scheme. The probability of error is computed for various system parameters such as a DS/SFH hybrid ratio, the number of jamming tones, a jamming-to-signal ratio, and a siganl-to-noise ratio. It is shown that a DS system or a SFH system achieves smaller probability of error than a hybrid DS/SFH system for most values of system parameters. However, it is also shown that there are hybrid ratios with which a hybrid DS/SFH system achieves smaller probability of error than a DS system and a SFH system achieve for some values of system parameters.

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A Study on the Performance of the Hybrid Ventilation System for Apartment Houses (공동주택의 하이브리드 환기시스템 성능평가 연구)

  • Chun, Chu-Young;Kim, Gil-Tae;Kim, Sang-Hee
    • Land and Housing Review
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    • v.3 no.1
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    • pp.89-96
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    • 2012
  • The purpose of this study was to evaluate the applicability of hybrid ventilation system in apartment housings and present a design method to improve the performance of hybrid ventilation system using the CFD simulation. As the object of CFD simulation, a small apartment houses with area of $51m^2$ and $81m^2$ were selected and evaluated. The test hybrid ventilation system are window frame natural air supply & duct exhaust hybrid system(Hybrid 1) and window frame natural air supply & bathroom and livingroom exhaust hybrid ventilation system(Hybrid 2). To evaluate the ventilation efficiency, we used the locations of diffuser installed for each system as the variables through the CFD simulation. In the case of Hybrid 1, the ventilation efficiency of the exhaust duct diffuser located on the inside room was higher rather than the exhaust duct diffuser located on the entrance. In the case of Hybrid 2, the most efficient system was the system that the diffuser connecting the bathroom static pressure fan is installed on the center of the living room. The ventilation efficiency of the Hybrid 2 in the case of $51m^2$ type was more than 20% of the Hybrid 1. But, The ventilation efficiency of the Hybrid 2 in the case of $84m^2$ type was more than 14% of the Hybrid 1. Therefore, to apply the Hybrid ventilation, a study that considers various variable should be conducted.

The study of proton exchange membrane fuel cell and Li-poly battery hybrid system (로봇용 연료전지 이차전지 하이브리드 시스템 연구)

  • Kwon, O-Sung;Lee, Sang-Cheol;Lee, Sang-Woo;Lee, Dong-Ha
    • Journal of the Korean Solar Energy Society
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    • v.32 no.spc3
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    • pp.282-288
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    • 2012
  • Proton exchange membrane fuel cell (PEMFC) is the most promising energy source for the robot applications because it has unique advantages such as high energy density, no power drop during operating, and easy to make compact size. However, PEMFC has intrinsic disadvantages which are delay to start up and difficulty to correspond drastic load changes. These disadvantages can be compensated by hybrid operating with a Li-poly battery. This study is focus to build and understand the hybrid system for the robot system. In this study, we build the PEMFC hybrid system using EOS-320 PEMFC stack, Li-poly battery and G-Philos FDX1-250BU dc-dc converter. The hybrid system is accurately monitored by CAN and RS485. The system was studied under two conditions such as non-loaded and loaded operating conditions. The results show that the system has delay to start up without hybrid operating and it can be compensated with the hybrid operating.

The study of proton exchange membrane fuel cell and Li-poly battery hybrid system (로봇용 연료전지 이차전지 하이브리드 시스템 개발)

  • Kwon, O-Sung;Lee, Sang-Cheol;Lee, Sang-Woo;Lee, Dong-Ha
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.229-233
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    • 2012
  • Proton exchange membrane fuel cell (PEMFC) is the most promising energy source for the robot applications because it has unique advantages such as high energy density, no power drop during operating, and easy to make compact size. However, PEMFC has intrinsic disadvantages which are delay to start up and difficulty to correspond drastic load changes. These disadvantages can be compensated by hybrid operating with a Li-poly battery. This study is focus to build and understand the hybrid system for the robot system. In this study, we build the PEMFC hybrid system using EOS-320 PEMFC stack, Li-poly battery and G-Philos FDX1-250BU dc-dc converter. The hybrid system is accurately monitored by CAN and RS485. The system was studied under two conditions such as non-loaded and loaded operating conditions. The results show that the system has delay to start up without hybrid operating and it can be compensated with the hybrid operating.

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Development of High Efficiency Gas Turbine/Fuel Cell Hybrid Power Generation System (가스터빈/연료전지 혼합형 고효율 발전시스템 개발)

  • Kim Jae Hwan;Park Poo Min;Yang Soo Seok;Lee Dae Sung
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.243-247
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    • 2005
  • This paper describes an on-going national R&D program for the development of a gas turbine/fuel cell hybrid power generation system and related R&D activities. The final goal of this program is to develop a 200kW-c1ass gas turbine/fuel cell hybrid power generation system and achieve high efficiency over $60\%$ (AC/LHV). In the first phase of the development, a sub-scaled 60kW-class hybrid system based on the 50kW-class microturbine and the 5kW SOFC will be developed for the purpose of concept proof of the hybrid system. Core components such as the microturbine and the SOFC system are being developed and parallel preparation for system integration is being carried out. Before the core components are assembled in the final system. operating characteristics of a hybrid system are investigated from a simulated system where a turbocharger (microturbine simulator) and a modified fuel cell burner test facility (fuel cell simulator) are employed. The 60kW demonstration unit will be built up and operated to provide the valuable information for the preparation of the final full scale 200kW hybrid system.

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Proposal of a Novel Plug-in-hybrid Power System Based on Analysis of PHEV System (PHEV 시스템의 분석을 통한 신 PHEV 동력 시스템 제안)

  • Kim, Jinseong;Park, Yeongil
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.4
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    • pp.436-443
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    • 2015
  • In order to develop the PHEV(plug-in hybrid electric vehicle), the specific power transmission systems considering the PHEV system characteristics should be applied. A PHEV applied to series-parallel type hybrid power transmission system is a typical example. In this paper, the novel hybrid power systems are proposed by analyzing the existing PHEV system. The backward simulation program is developed to analyze the fuel efficiency of hybrid power system. Quasi-static models for each components such as engine, motor, battery and vehicle are included in the developed simulation program. To obtain an optimal condition for hybrid systems, an optimization approach called the dynamic programming is applied. The simulation is performed in various driving cycles. A weakness for the existing system is found through the simulation. To compensate for a discovered weakness, novel hybrid power systems are proposed by adding or moving the clutch to the existing system. Comparing the simulation results for each systems, the improved fuel efficiency for proposed systems are verified.

Implementation of a Hybrid Navigation System for a Mobile Robot by Using INS/GPS and Indirect Feedback Kalman Filter (INS/GPS와 간접 되먹임 칼만 필터를 사용하는 이동 로봇의 복합 항법 시스템의 구현)

  • Kim, Min J.;Joo, Moon G.
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.6
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    • pp.373-379
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    • 2015
  • A hybrid navigation system is implemented to apply for a mobile robot. The hybrid navigation system consists of an inertial navigation system and a global positioning system. The inertial navigation system quickly calculates the position and the attitude of the robot by integrating directional accelerations, angular speed, and heading angle from a strap-down inertial measurement unit, but the results are available for a short time since it tends to diverge quickly. Global positioning system delivers position, heading angle, and traveling speed stably, but it has large deviation with slow update. Therefore, a hybrid navigation system uses the result from an inertial navigation system and corrects the result with the help of the global positioning system where an indirect feedback Kalman filter is used. We implement and confirm the performance of the hybrid navigation system through driving a car attaching it.