• 한국자동차공학회논문집
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• 제10권2호
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• pp.1-8
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• 2002

The flow and combustion patterns have been investigated inside the gasoline engine cylinder with the swirl or tumble flow, whereas the air flow characteristics, which are generated in the part of intake system before entering into the intake manifold, have not been known completely. It is necessary to analyze the flow field in the intake system consisting of air rater, throttle valve and intake manifold. The throttle valve, used to control the intake air flow rate, is important because it makes various mass flow rate and flow patterns. Three-dimen-sional How characteristics such as velocities, turbulent intensities and Reynolds shear stresses are measured by the hot wire anemometer at the exit of the throttle valve with the variation in the valve opening angle($15^{\circ}$, $45^{\circ}$, $75^{\circ}$ and $90^{\circ}$) and the Reynolds numbers (45000, 70000 and 140000). There are a lot of changes in flow characteristics at $75^{\circ}$ due to the large recirculation flow comparing with those of the other cases, and the streamwise velocity is especially enforced strongly below the valve shaft. The other component velocities are relatively large near the centerline parallel to the valve shaft. The effects of the Reynolds number on the flow field are not severe.

• 로봇학회논문지
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• 제2권1호
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• pp.1-8
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• 2007

This paper presents a PID automatic gain-tuning algorithm for the electronic throttle valve which is driven by wire. Since the system characteristics of position control for electronic throttle valve are so complicated that both the real time robustness and the manufacturing cost must be considered for mass production. To resolve this paradox, a kind of algorithm called RLS (Recursive Least Square) is adopted for the control of the ETB (Electronic Throttle Body). Using this algorithm, the PID gains can be adjusted automatically with the estimated system parameters. Furthermore, a pre-filter is supplemented for the sake of the robustness against the friction and loads. From the industrial requests for the system, the design specifications are decided as follows: the settling time should be less than 1sec and the overshoot should be kept below 3%. The results of the experiments based on this approach show that the high robustness can be achieved while the system stability is satisfied steadily. A parameter estimation scheme and a gain-tuning algorithm have been properly combined and utilized in this research and the effectiveness is verified through the real experiments.

• 한국산업융합학회 논문집
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• 제20권4호
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• pp.313-323
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• 2017

As vehicles become more intelligent this is focused on ways to enhance safety and convenience for both drivers and passengers. In particular, x-by-wire systems that replace rigid mechanical components with dynamically configurable electronic elements are being developed to expand intelligent functions, such as adaptive cruise control or lane departure warning system. Because the malfunction of safety-related modules controlling critical functions, such as brakes, throttle, and steering in x-by-wire systems, can cause injury or death, safety and reliability are the most critical issue for automotive vendors and parts manufacturers. In an effort to develop better and effective brake-by-wire system, this paper presents EMB system by using the low speed electric vehicle, which is not required large braking force, with motor controller. In addition, we design performance evaluation system of EMB with 1/4 low speed electric vehicle model and suggested EMB is evaluated through the performance evaluation system.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2209-2217
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• 2006

Dynamic flow characteristics of a counter-flow vortex tube is investigated using hot-wire and piezoelectric transducer (PZT) measurements. The experimental study is conducted over a range of cold air outlet ratios (Y=0.3, 0.5, 0.7, and 1.0) and inlet pressure 0.15 MPa. Temperatures are measured at the cold air outlet and along the vortex tube wall. Hot-wire is located at cold outlet and PZT is installed at inner vortex tube by mounting at throttle valve. The cold outlet temperature results show that the swirl flow of vortex tube is not axisymmetric. The hot-wire and PZT results show that there exist two distinct kinds of frequency, low frequency periodic fluctuations and high frequency periodic fluctuations. It is found that the low frequency fluctuation is consistent with the Helmholtz frequency and the high frequency fluctuation is strongly related with precession oscillation.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.122-125
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• 2003

For Lab-scale Hybrid Rocket's Ignition, It is needs of heat source to vaporize solid fuel. We used Nichrome wire which has a electric resistance for ignition. But Ignition system by using Nichrome wire is not only the disposable system, but also the system which has an affect on the Hybrid rocket's structures(nozzle throat diameter). The new Ignition system composed of Butane+propane gas' supply devices and spark plug. RPL(Rocket Propulsion Lab.) perform the hybrid rocket experiments over 50 times by using new ignition system. The fact that is possible to throttle the Thrust in hybrid rocket is confirmed.

• 항공우주시스템공학회지
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• 제3권3호
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• pp.32-38
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• 2009

An autothrottle module for small jet aircraft Fly-By-Wire system was developed. The autothrottle was designed to be composed of DC geared motor and electro-magnetic clutch that enables smooth manual/auto switching. A controller was designed for simple position control using ON/OFF control method with a commercial motor driver. The autothrottle developed was installed in the cockpit mockup and interfaced to the flight control computer for the HILS test. The performance test proved that the throttle lever follows well the command signal from the flight control computer.