• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.125-130
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• 1995

Recently, the vehicle engine requried precision control of Air-Fuel rate and rigid restriction of exhaust gas. Therefore, we demanded excellent measuring equipment so as to improve of engine performance. Specially, throttle valve control is very important part in the engine control, because structure of engine dynamometer system is very important part in the engine control, because structure of engine dynamometer system is very complicate and it has nonlinear elements which is influenced of disturbance about vibration, a heat, a cooling, energy loss so on. In this study, we propose the method that the control technique using Fuzzy Look-up table and we obtained the satisfying result from realized the control system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.703-707
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• 2007

The line pressure control system for an automotive transmission in which a bleed type variable force solenoid(VFS) is applied, has been constructed and experimentally investigated. The hydraulic circuit of the system includes a line pressure control valve, a reducing valve, an accumulator, various orifices and a VFS. Static and dynamic responses of the throttle and line pressure have been monitored and discussed for various test conditions.

• Resources Recycling
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• v.25 no.4
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• pp.11-22
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• 2016

In global automobile industry, the remanufacturing for used products has the merit to be reduced nearly 80 percent of energy consumption and resources of new product. The objective of this paper is the analysis of detailed remanufacturing processes about research object and failure modes of each process of throttle body which is one of automobile parts, to draw a FMEA and determine the degree of seriousness (S), detection (D) and occurrence (O) of many failures. And we compared the current RPN method of being used to calculate values of RPN with three suggested methods. : Summation method, Square root method, Volume method.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.91-98
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• 1999

This paper describes the air flow characteristics inside the throttle valve. Tow-dimensional steady incompressible Navier-Strokes equation are solved numerically with embedding the conceopt of the artificial compressibility and adopting the Baldwin-Lomax turbulence model. With varying the valve opening angles(the Reynolds number )such as 15$^{\circ}$(5000) , 45$^{\circ}$(3000) , 75$^{\circ}$(7000) and 90$^{\circ}$(10000), respectively. tow cases, with a valve shaft and without one, are analysed. The pressure loss between the entrance and exit is severe at 15$^{\circ}$, 100 times as larger as that of 90$^{\circ}$ case, which also depends much on the existece of the valve shaft. The counter rotating vortices are formed over the valve plate with the shaft at only 75$^{\circ}$. They are smally and very large scale in front and back of the valve shaft , respectively. The velocity profiles of 15$^{\circ}$ and 90$^{\circ}$ at the exit are almost symmetric to the horizontal center line, however, the symmetricity is no longer maintained at 45$^{\circ}$ and 75$^{\circ}$ , and in addition, the flow at 75$^{\circ}$ is enforced a lot below center line. The pressure distribution on the walls is largely changed near the valve shaft, and its magnitude becomes great as the valve angle decreases.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.4
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• pp.73-78
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• 2011

When a liquid rocket engine - specifically for the gas-generator cycle engine has throttle valves to control the thrust level and mixture ratio of the engine, it is possible to adjust the inherent flow characteristics of the control valves in order to secure a linearized correlation between the control-process-parameters like the thrust or mixture ratio of an engine and the throttle angle of valve. These linearities can reduce the complexity of the control process and make the process more explicit by ensuring the intuitive control. In this point, we proposed an algorithm within the frame of the in-house-developed program to obtain the control valves' inherent flow characteristics which satisfy the linearity, and calculated the sensitivities of control valves with respect to the throttle angle. Also, we compared the obtained inherent flow characteristics with the existed data and concluded the results are satisfactory.

• Journal of Biosystems Engineering
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• v.16 no.2
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• pp.111-117
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• 1991

An empirical model for diesel engine control was obtained using a system identification method. A pseudo-random binary sequence was used as an input signal. Spectral anaylsis was used to find the frequency response of system. Model parameters of transfer functions were obtained using nonlinear regression.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.47-47
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• 2000

당사는 진공 및 반도체 장비용 major components 국산화 개발을 전문으로 하는 회사로서 주로 vacuum과 gas control 부문 개발에 역점을 두고 있습니다. 현재 생산 혹은 차후 개발하고자 하는 제품은 다음과 같다. MFC power supply & Readout unit(GMC 1000, GMC 100A, GMC110A), Vacuum Controller(GVC2000, GVC1000, GVC2002), Throttle valve Controller & Pressure Display unit(GPC3000), MFC 등을 생산/판매하고 있다.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.139-147
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• 2004

The purpose of engine control TCS is to regulate engine torque to keep driven wheel slip in a desired range. In this paper, engine control TCS using sliding mode control law based on engine model and estimated load torque is proposed. This system includes a two-level controller. Slip controller calculates desired wheel torque, and engine torque controller determines throttle angle for engine torque corresponding to desired wheel torque. Another issue is to measure load torque for model based controller design. Luenberger observer with state variables of load torque and engine speed solves this problem as estimating load torque. The performance of controller and observer is certificated by simulation using 8-degree vehicle model, Pacejka tire model, and 2-state engine model. The simulation results in various maneuvers during slippery and split road conditions showed that acceleration performance and ability of the vehicle with TCS is improved. Also, the load torque observer could estimate real load torque very well, so its performance was proved.

• International Journal of Fluid Machinery and Systems
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• v.10 no.2
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• pp.176-188
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• 2017

The nozzle-flapper valves are widely applied as a pilot stage in aerospace and military system. A subject of the analysis presented in this work is to find out a reasonable range of null clearance between the nozzle and flapper. This paper has presented a numerical flow coefficient simulation. In every design point, a parameterized model is created for flow coefficient simulation and cavitation under different conditions with varying gap width and inlet pressure. Moreover, a new test device has been designed to measure the flow coefficient and for visualized cavitation. The numerical simulation and test results both indicate that cavitation intensity gets fierce initially and shrinks finally as the gap width varies from small to large. From the curve, the flow coefficient mostly has experienced three stages: linear throttle section, transition section and saturation section. The appropriate deflection of flapper is recommended to make the gap width drop into the linear throttle section. The flapper-nozzle null clearance is optionally recommended near the range of $D_N/16$. Finally through simulation it is also concluded that the inlet pressure plays a little role in the influence on the flow coefficient.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.212-219
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• 1998

Unburned hydrocarbon is a key contributor to both the fuel economy and emissions of automotive engine. Cyclic variation of HC emission is of importance, especially during throttle transients. The real time measurement of hydrocarbon is particularly important to obtain a better understanding of the mechanisms for combustion and emissions, especially during cold start and throttle transient condition. This paper reports the cycle resolved measurement technique of unburned hydrocarbons to quantify rapid changes of in-cylinder concentration in the vicinity of spark plug by using the Fast Response Flame Ionization Detector(FRFID). While this instrument actually measures fuel concentration, its results can be indicative of the AFR behaviour. In order to understand the rapid change of hydrocarbons with cylinder pressure, it is necessary to study the response time delay of the system, including the time associated with gas transportation to FID. And signal from FRFID is correlated with cylinder pressure data to relate changes in mixture preparation to the classic analysis, such as indicated mean effective(IMEF) and ignition delay, etc.