• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.915-921
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• 2012

In this study, we propose a new method for estimating the IMEP using difference pressure, which is the pressure difference between the cylinder pressure and the motoring pressure. The estimated IMEP, denoted as $IMEP_{diff}$, optimizes the theoretical IMEP calculation range based on the fact that the difference pressure exists between the start and the end of combustion. $IMEP_{diff}$ is verified to have a high linear correlation with IMEP with $R^2$ of 0.9955. The proposed method can estimate the IMEP with 21% of the cylinder pressure data and 31% of the calculation effort compared to the theoretical IMEP calculation method, and therefore, it has great potential for real-time implementations. The estimation and control performance of $IMEP_{diff}$ is validated by engine experiments, and by controlling $IMEP_{diff}$, the torque variation between the cylinders was reduced.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.1064-1065
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• 2017

트레드밀 인터페이스는 사용자의 보행 모션을 인식하여 가상세계를 네비게이션 할 수 있는 보행 플랫폼이다. 특히 작은 보행 영역을 가지는 트레드밀의 경우, 보행자 속도 예측 방법에 의해 더욱 효과적인 지면 모션의 생성이 가능하다. 본 연구에서는 착용형 압력 센서로 부터 측정되는 족부 압력 데이터를 기반으로 하는 보행속도 예측 방법과 트레드밀 제어 방법을 제시하고자 한다. 속도 예측은 지면 반발력 데이터 중 압력중심의 변화 속도를 통해 도출되며, 예측된 속도를 트레드밀 속도 제어에 안정적으로 적용하기 위한 피드포워드 제어 방법을 제시한다. 또한 족부 압력 데이터 측정이 가능한 자율 제어 트레드밀 시스템 구현과 보행 실험 과정을 소개한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.18-21
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• 2011

In this study, basic research on the pressure control using driven pintle of modulatable thruster is presented. For this purpose, pintle thruster and pintle shape was developed. The actuator model was selected by calculating pintle load using Fluent software. Preliminary unsteady experimental results show that huge pressure oscillation is occurred as the pintle approach toward nozzle wall. From the preliminary experimental results, we could see possibility of pressure control of the modulatable thruster.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.119-122
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• 2009

Numerical computations were carried out to analyze the effect of inlet Mach number and sub-cavity on the control of cavity-induced pressure oscillations in two-dimensional supersonic flow. A passive control method wherein a sub-cavity was introduced on the front wall of a square cavity was studied for Mach numbers 1.50, 1.83 and 2.50. The results showed that sub-cavity is effective in reducing the oscillations at different inlet Mach numbers. The resultant amount of attenuation of pressure oscillations depended on the inlet Mach number, length of the flat plate, and the depth of the sub-cavity used as an oscillation suppressor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5997-6003
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• 2011

To increase the driving distance of a natural gas vehicle, the high pressure of fuel charge is necessary and the development of the device reducing the pressure to suitable pressure for fuel of high pressure. In this study, Pressure characteristics at the pressure regulator, which is very important for gas supply systems for vehicles, are investigated. Numerical simulations are carried out to quantify pressures at regulators for several flow rates and to investigate pressure drop, hysteresis losses at some parts in the pressure regulator. Moreover, this paper presents a new kind of hydraulic simulation which is composed of CNG regulator. Lastly, experiments are carried out to verify the effectiveness of the prosed mathematical simulation with various regulator components as in real working condition.

• 연구논문집
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• s.28
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• pp.21-37
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• 1998

Atmospheric pressure in a tunnel rises in proportion to the square of train’s speed as it enters a tunnel. This pressure difference propagates into the train and cause aural discomfort to the passengers. In order to alleviate the aural discomfort of them. a new ventilation system has been designed and tested. This system controls the charged and discharged by flow rate by detecting the air pressure generated outside and inside of the train. Test to confirm the fundamental performance of the system was carried out. Consequently, this system was found to be able to alleviate the aural discomfort effectively. Application of the system to TGV-K running in the speed range of 350km/h is considered to have good propospect.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.167-174
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• 2011

Solid propulsion systems have simple structures compared to other propulsion systems and are suitable to long-term storage. However the systems generally have limits on control of thrust levels. In this paper we suggest control algorithms for combustion chamber pressure of variable thrust solid propulsion systems using special nozzles such as pintle valve. For this we use a simple pressure change model by considering only mass conservation within the combustion chamber, design a classical algorithm and also a nonlinear controller using feedback linearization technique. Derived thrust equation and designe a thrust control model. We design the proportion-integral controller for linearizing about operating point. We also demonstrate the performance of controller model through numerical simulations.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.10
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• pp.992-997
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• 2010

The Propulsion Control Module(PCM) of Hall-thruster Propulsion System(HPS) for Science and Technology Satellite-3 (STSAT-3) has the flow control accuracy of less than ${\pm}$3% and the pressure control accuracy of less than ${\pm}$5%. The pressure controller adjusts pressure around the set point by using a Proportional Flow Control Valve (PFCV) and a high pressure transducer, while the flow controller regulates the flow rate using PFCV and the anode current telemetry of the Hall Thruster. The controllers are chosen as the Proportional and Integral(PI) type, and the PI gains are tuned based on the Matlab simulations. The result of the PCM test had the flow control accuracy of less than ${\pm}$1.87% and the pressure control accuracy of less than ${\pm}$5%. This paper describes the design, realization, and performance test results of the PCM.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.119-122
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• 1996

본 논문은 Building, 아파트, 병원 호텔 등의 건물의 급수 System으로서 최근 대두되고 있는 Bosster Pump System에 관한 것으로서, 제품의 주요 특징 및 제어 알고리즘을 소개하고 특히 최종 User에게 쾌적한 급수 환경을 제공하기 위한 주 제어 기능인 일정 예측 최종 압력 제어를 PID 및 Fuzzy 제어이론을 이용하여 구현하였는데, 그 적용 알고리즘을 소개하고, 실제 제어 실험을 통해 PID제어와 Fuzzy 제어를 비교하였다.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.71.2-71.2
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• 2005