• 유공압시스템학회논문집
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• 제5권4호
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• pp.1-9
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• 2008

In this paper, an energy regeneration algorithm is proposed to make the maximum use of the regenerative braking energy for a parallel hybrid electric vehicle(HEV) equipped with a continuous variable transmission(CVT). The regenerative algorithm is developed by considering the battery state of charge(SOC), vehicle velocity and motor capacity. The hydraulic module consists of a reducing valve and a power unit to supply the front wheel brake pressure according to the control algorithm. In order to evaluate the performance of the regenerative braking algorithm and the hydraulic module, a hardware-in-the-loop simulation (HILS) is performed. In the HILS system, the brake system consists of four wheel brakes and the hydraulic module. Dynamic characteristics of the HEV are simulated using an HEV simulator. In the HEV simulator, each element of the HEV powertrain such as internal combustion engine, motor, battery and CVT is modelled using MATLAB/$Simulink^{(R)}$. In the HILS, a driver operates the brake pedal with his or her foot while the vehicle speed is displayed on the monitor in real time. It is found from the HILS that the regenerative braking algorithm and the hydraulic module suggested in this paper provide a satisfactory braking performance in tracking the driving schedule and maintaining the battery state of charge.

• 한국물환경학회지
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• 제22권6호
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• pp.1144-1150
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• 2006

Recently, as water pollution accidents in rivers have increased, there is an increased interest in water quality forecast with accurate simulation. QUAL2E model, widely used for water quality analysis, uses the same hydraulic characteristics, such as depth and velocity, in a reach. The flow of the river is changed by various hydraulic constructions or by topography in a real river channel. In this study, a hydraulic connection module is developed to consider flow variations of river channels in QUAL2E model. The module uses the simulations results of non-uniform flow of a 1-D hydraulic model such as DWOPER or HEC-RAS. The improved QUAL2E model with this module was applied to a downstream section of Paldang Dam on the Han River. The results show the variation of water quality very well in a reach where flowing vary abruptly, like the Jamsil submerged weir.

• 오토저널
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• 제15권3호
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• pp.36-46
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• 1993

In CVT vehicle, the engine speed is completely decoupled from the vehicle speed within the range from maximum transmission ratio to minimum transmission ratio. This allows the engine to operate in optimal state(e.g. best fuel economy or maximum power mode.) In this study, the CVT control algorithm for optimal operation of engine is suggested. In order to implement the real time digital control of electro-hydraulic CVT system, a software called CVTCON has been developed. CVTCON also includes the CVT operation module, (2) system test module, (3) system control module and (4) data management module. By using the CVTCON and the electro-hydraulic CVT system, two modes of experiments were carried out: constant throttle opening mode and acceleration mode. From the experimental result, it was found that the algorithm suggested in this study showed optimal operation of the CVT system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.283-288
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• 2001

This study provides analytical evaluation of the Dual-Ann Work Module. The current hydraulic system was modeled using the HyPneu and analyzed to find the cause of the instability. The cause of the instability was determined to be primarily an interacting involving the pilot operated check valves and the counterbalance valves for fail safe mode of operation. A new design concept was developed to eliminate the potential for unstable operation while adequately meeting the need for a fail-safe feature.

• 한국기계가공학회지
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• 제19권10호
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• pp.31-35
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• 2020

Hydraulic winches for transportation and logistics in the shipbuilding and marine plant fields require multi-stage planetary gear modules with high gear ratios. Due to environmental conditions in the ship, durability is crucial. Further, we are currently relying on foreign products. The development of domestic technology will reduce cost, save time, and improve the export market. Thus, we developed a multi-stage planetary gear module for a hydraulic winch and evaluated its performance through several tests of the hydraulic brake torque, maximum torque, and load endurance.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.282-287
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• 2003

DTTS(Dynamic Track Tensioning System) system requires robust control performance for the various maneuvering tasks. However, it is very difficult to tune the controller gains in experiments. In this paper, the hydraulic unit is modeled and constructed into the DTTS control module in Matlab/Simulink The control module is interfaced to the vehicle dynamics module so that the control performance of the DTTS system can be evaluated in simulations. The dynamics data and control input data are exchanged between two modules at each control time-step. The gains in the fuzzy-logic controller are varied and the control performance is evaluated in simulations. The proposed simulation tool can be very useful for the gain tuning of track tension controller in bucked vehicles

• 항공우주시스템공학회지
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• 제16권3호
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• pp.84-92
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• 2022

전기-정유압식 작동기(EHA)는 독립적으로 유동력원을 운용함에 따라, 복잡한 유압 배관을 제거할 수 있어 누유 및 중량 최소화, 안전성 향상의 장점이 있어 최근 항공기용 비행제어 분야에서 사용되고 있다. 이러한 EHA를 탑재하는 항공기의 경우, 기존 중앙 유압시스템을 탑재한 항공기에 비해 제한된 냉각원에 따른 EHA의 열관리 이슈가 대두된다. 이러한 열관리 이슈의 해결을 위해서는, EHA의 열특성을 예측할 수 있는 열해석 모델이 필요하다. 본 연구에서는 유압펌프 및 전기모터로 구성되는 EHA 유압동력모듈의 내부 회전체를 고압 하에서 고속으로 회전이 가능하도록, 유압동력모듈 내부에 유체 순환 회로를 적용하였다. 적합한 열해석 모델을 구축하고, 유냉식 또는 비유냉식 유압동력모듈 적용에 따른 해석 결과의 비교 및 검토를 통해 EHA의 열특성 영향성을 확인하고자 하였다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.596-597
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• 2005

• 한국생산제조학회지
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• 제5권3호
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• pp.22-30
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• 1996

In order to compensate for out-of-straightness of shafts, an automatic straightening process composed of an automatic measuring module, an automatic control unit and operating softwares was developed with a hydraulic press. The out-of-sraightness of each shaft was measured automatically in the measuring stage. An optimal pressure point was determined to minimize TIR value of the shaft according to press count of 3-points bending process. In the geometric adaptive control procedure, punch stroke and springback of the shaft were predicted by an observer using on-line measured values of press force and deflection amount I each press count. An automatic straightening machine was realized with the measuring module, the GAC module, PLD, IBM-PC and the operating software on the hydraulic press. the validity of the proposed straightening process was confirmed through a series of experiments with cam shafts.

• 한국기계가공학회지
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• 제21권2호
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• pp.73-78
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• 2022

The test apparatus that can be protected from the high-temperature combustion flame and coolant injection was successfully manufactured. In this study, the coolant-injection module had a controllable consistent pressure, and the entire combustion module was protected using a nonflammable composite liner. Every flange was designed in accordance with the DIN standard, and the entire body of the module was designed in accordance with the EN 13445 code. Additionally, the hydraulic pressure test was performed in accordance with the 2014/68/EU directive and EN 13445 standard. Finally, after manufacturing, performance tests (such as pressure tests) were conducted to verify the reliability and safety.