• Title/Summary/Keyword: Optimal Efficiency Driving

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Map Matching Algorithm Using Continuous GPS Coordinates (연속 GPS좌표를 이용한 지도 매칭 알고리즘)

  • Park, Do-Young;WhangBo, Taeg-Keun
    • Journal of Korea Spatial Information System Society
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    • v.4 no.1 s.7
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    • pp.27-37
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    • 2002
  • Ideas providing an optimal car route using current traffic condition, maintaining the current location and the history of driven route of a car in the main central office, in where GPS signals transmitted from the driving cars are received, have been proposed. Since GPS signals occurred in certain time interval instead of all GPS signals are transmitted from the car due to the cost of transmission, an algorithm that is able to recover the missing GPS signals is required. In this paper, an efficient algorithm, which finds the driven route and the current location of a car fast, is proposed. To verify the efficiency of the proposed algorithm, it is applied to the various real GIS map and it turns out to be very effective.

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A Study for Application of Active Magnetic Bearing using Quantitative Feedback Theory (Quantitative Feedback Theory를 이용한 능동 자기베어링의 적용 연구)

  • Lee, Gwan-Yeol;Lee, Hyeong-Bok;Kim, Yeong-Bae
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.11
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    • pp.107-115
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    • 2001
  • Most of rotating machineries supported by contact bearing accompany lowering efficiency, vibration and wear. Moreover, because of vibration, which is occurred in rotating shaft, they have the limits of driving speed and precision. The rotor system has parametric variations or external disturbances such as mass unbalance variations in long operation. Therefore, it is necessary to research about magnetic bearing, which is able to support the shaft without mechanical contact and to control rotor vibration without being affected by external disturbances or parametric changes. Magnetic bearing system in the paper is composed of position sensor, digital controller, actuating amplifier and electromagnet. This paper applied the robust control method using quantitative feedback theory (QFT) to control the magnetic bearing. It also proposed design skill of optimal controller, in case the system has structured uncertainty, unstructured uncertainty and disturbance. Reduction of vibration is verified at critical rotating speed even external disturbance exists. Unbalance response, a serious problem in rotating machinery, is improved by magnetic bearing using QFT algorithm.

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A Study on Pick-up Device of Beep Sea Manganese Nodules Collector (심해저 망간단괴 집광기의 채집장치에 관한 연구)

  • Hong, Sub;Sim, Jae-Yong;Lee, Tae-Hee;Choi, Jong-Soo
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.891-895
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    • 1996
  • Performance and efficiency of hybrid (hydraulic-mechanical) pick-up device of deep sea manganese nodules collector are very sensitive to altitude and altitude of pick-up head relative to undulating seafloor. For this reason, motion control of pick-up head relative to the changing deep sea topography and other disturbances is of particular importance in design of pick-up device. The concept of design axiom is applied to a pick-up device of hybrid type. Kinematic analysis conducted in absolute Cartesian coordinates gives position, velocity, and acceleration of the hydraulic cylinders which enable the pick-up head to keep the preset optimal distance from seafloor. Inverse dynamic analysis provides the driving forces of hydraulic cylinders and the reaction forces at each joint. Design sensitivity analysis is performed in order to investigate the effects of possible design variables on the change of the maximum strokes of hydraulic cylinders. The direct differentiation method is used to obtain the design sensitivity coefficients.

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Design of Vehicle Control Algorithm and Engine-generator Control for Drivability of Range-extended Electric Vehicle (주행거리 연장형 전기자동차의 차량제어 알고리즘 설계 및 운전성 확보를 위한 엔진 발전시스템 제어)

  • Park, Youngkug
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.6
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    • pp.649-659
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    • 2016
  • This paper describes control algorithm and control structure of vehicle control unit for range-extended electric vehicle equipped with engine-generator system, and specially presents methods which determine optimal operating points and decreases a vibration or a shock for operating the engine-generating system. The vehicle control algorithm is consisted of several parts which are sequence control, calculation of wheel demand torque, determination of operating points, and management of operating points and so vehicle controller has be made possible to efficiently manage calibration parameters. The control algorithm is evaluated by driving test modes, launching performance and operating engine-generator system and so on. In conclusion, this paper present methods for extending a mileage, improving a launching performance and reducing vibration or shock when the engine-generating system is starting or is stopping.

An Electric-Field Coupled Power Transfer System with a Double-sided LC Network

  • Xie, Shi-Yun;Su, Yu-Gang;Zhou, Wei;Zhao, Yu-Ming;Dai, Xin
    • Journal of Power Electronics
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    • v.18 no.1
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    • pp.289-299
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    • 2018
  • Electric-field coupled power transfer (ECPT) systems employ a high frequency electric field as an energy medium to transfer power wirelessly. Existing ECPT systems have made great progress in terms of increasing the transfer distance. However, the topologies of these systems are complex, and the transfer characteristics are very sensitive to variations in the circuit parameters. This paper proposes an ECPT system with a double-sided LC network, which employs a parallel LC network on the primary side and a series LC network on the secondary side. With the same transfer distance and output power, the proposed system is simpler and less sensitive than existing systems. The expression of the optimal driving voltage for the coupling structure and the characteristics of the LC networks are also analyzed, including the transfer efficiency, parameter sensitivity and total harmonic distortion. Then, a design method for the system parameters is provided according to these characteristics. Simulations and experiments have been carried out to verify the system properties and the design method.

An Experimental Approach to Evaluate the Desulfurization Yield in Spray Drying Sorber (반건식 세정기의 산성가스 제거성능에 관한 실험적 연구)

  • Yang, Hyun-Mo;Kim, Sang-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.4
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    • pp.589-598
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    • 2000
  • A pilot-scale Spray Drying Sorber (SDS) system was set up to evaluate the effect of spray characteristics on the desulfurization yield. The size distribution and the Sauter Mean Diameters of slurry droplets were measured in advance using the optical size measurement system, Malvern 2600. The desulfurization yield of the drying chamber by size was measured for the conditions of inlet gas and spray injection. As a reagent, 10% limestone slurry of $Ca(OH)_2$ was treated with flue gas containing $SO_2$, and the combustion gas analyzer and gas detectors were attached to measure the $SO_2$ concentration. With a flow rate of 144 Nm3/h and a temperature range of $200{\sim}300^{\circ}C$, the experiments were performed for the Stoichiometric Ratio (SR) of 1.0 to 3.0 and droplet mean diameter of 6.5 to $34.3{\mu}m$. In case of smaller spray droplets, the desulfurization efficiency improved due to the increase of total droplet surface area, while the reduction in evaporation time reduced the contact time between the droplets and $SO_2$ gas. In some typical region of droplet diameter, this negative effect, reduction of contact time, became dominant and the desulfurization yield decreases the desulfurization yield in spite of the expansion in absorption area. These results revealed that there exists the optimal size of spray droplets for a given state, which is determined by the compromise between the total surface area of slurry droplets and the evaporation time of droplets. The measurements also indicated that the inlet temperature of flue gas changes the optimal injection condition by varying the driving force for evaporation. The results confirm that the effect of the evaporation time of slurry droplets should be considered in analyzing the desulfurization yield as well as the total surface area, for it is a significant aspect of the correlation with the capabilities of $SO_2$ absorption in wet droplets. In conclusion, the optimal condition of spray can be determined based on these results, which might be applied to design or scale-up of SDS system.

Development of DC/DC Converters and Actual Vehicle Simulation Experiment for 150 kW Class Fuel-cell Electric Vehicle (150kW급 수소연료전지 차량용 DC/DC 컨버터 개발 및 실차모사 실험)

  • Kim, Sun-Ju;Jeong, Hyeonju;Choi, Sewan;Cho, Jun-Ho;Jeon, Yujong;Park, Jun-Sung;Yoon, Hye-Sung
    • The Transactions of the Korean Institute of Power Electronics
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    • v.27 no.1
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    • pp.26-32
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    • 2022
  • This paper proposes a power system that includes a 120k W fuel cell DC-DC converter (FDC) and 30 kW bidirectional DC-DC converter (BHDC) for a 150 kW fuel-cell vehicle. With a high DC link voltage of 800 V, the efficiency and power density of the power electronic components are improved. Through the modular design of FDC and BHDC, electric components are shared, resulting in reduced mass production costs. The switching frequency of 30 kHz of full SiC devices and optimal design of coupled inductor reduce the volume, achieving a power density of 8.3 kW/L. Furthermore, a synergetic operation strategy using variable limiter control of FDC and BHDC was proposed to efficiently operate the fuel cell vehicle considering the fuel cell stack efficiency according to the load. Finally, the performance of the prototype was verified by Highway Fuel Economy Driving Schedule testing, EMI test, and the linked operation between FDC and BHDC. The full load efficiencies of the FDC and BHDC prototypes are 98.47% and 98.74%, respectively.

Design of X-band 40 W Pulse-Driven GaN HEMT Power Amplifier Using Load-Pull Measurement with Pre-matched Fixture (사전-정합 로드-풀 측정을 통한 X-대역 40 W급 펄스 구동 GaN HEMT 전력증폭기 설계)

  • Jeong, Hae-Chang;Oh, Hyun-Seok;Yeom, Kyung-Whan;Jin, Hyeong-Seok;Park, Jong-Sul;Jang, Ho-Ki;Kim, Bo-Kyun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.11
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    • pp.1034-1046
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    • 2011
  • In this paper, a design and fabrication of 40 W power amplifier for the X-band using load-pull measurement of GaN HEMT chip are presented. The adopted active device for power amplifier is GaN HEMT chip of TriQuint company, which is recently released. Pre-matched fixtures are designed in test jig, because the impedance range of load-pull tuner is limited at measuring frequency. Essentially required 2-port S-parameters of the fixtures for extraction optimal input and output impedances is obtained by the presented newly method. The method is verified in comparison of the extracted optimal impedances with data sheet. The impedance matching circuit for power amplifier is designed based on EM co-simulation using the optimal impedances. The fabricated power amplifier with 15${\times}$17.8 $mm^2$ shows the efficiency above 35 %, the power gain of 8.7~8.3 dB and the output power of 46.7~46.3 dBm at 9~9.5 GHz with pulsed-driving width of 10 usec and duty of 10 %.

Performance Test of the Dual Mode Hybrid Systems (듀얼 모드 하이브리드 시스템의 성능 평가)

  • Kim, Nam-Wook;Yang, Si-U;Yang, Ho-Rim;Cho, Sung-Tae;Park, Yeong-Il;Cha, Suk-Won
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.6
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    • pp.87-93
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    • 2007
  • It is complicate to analysis the systems, dual mode hybrid systems, because they are composed of many planetary gear sets. For the performance test, it needs to define the systems with representative parameters. In this paper, system parameters, $\alpha$, $\beta$, $\zeta$, are introduced to define the systems, and an arbitrary system like E-IVT developed by Renault Motors is converted to the general system having equivalent parameters, such as $\beta'$, $R'_b$. Pontryagin principle and Kuhn-Tucker condition method are applied to solve the constrained problems, by which the methodology for accelerating test is generalized, and the results of the simulation are reported. In addition, the effects of alternative strategies are mentioned. The method of fuel economy test at engine mode is also introduced. The results of test at engine mode is different from the results of optimal trajectory, but the fuel economy of the engine mode is related to the highway driving and optimized operating of the system.

Secondary Concentration Technology of Brine from Membrane Seawater Desalination Process with Electrodialysis (전기투석을 이용한 분리막 담수화 공정 배출 농축수의 이차 농축기술)

  • Moon, Jeong-Ki;Park, Kwang-Seok;Yoo, Yoon-Ki;Yun, Young-Ki
    • Transactions of the KSME C: Technology and Education
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    • v.1 no.1
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    • pp.69-73
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    • 2013
  • This study is about the secondary concentration technology using electrodialysis process for minimum discharge and maximize recovery ratio from seawater desalination by reverse osmosis process. The experimental method adopted the constant voltage driving method and, concentrated/desalination volume capacity ratio changes, voltage changes and electrolyte types. Multi-ion membrane is used, aiming to derive conditions to minimize the TDS concentration of desalination water, to minimize the volumes of secnodary concentraion water and minimizing the power efficiency. The results of this study are as follows. The optimal ratio of concentraion/desalination volume is 1:5, the final TDS concentration of desalinated water is 5.32g/l, the final secnodary concentrated water salinity is 17.07% and electric energy demands of desalinated water is $16.74kWh/m^3$.