• Tribology and Lubricants
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• 제22권1호
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• pp.47-52
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• 2006

It is very important to control pressure and flow rate distribution on each component of engine lubrication network. Sometimes many kinds of orifice are used to control flow rate in the hydraulic lubrication field. In this study orifices were adopted on the lubrication network to control oil flow rate distribution. And unsteady transient flow network analysis was carried out to find out the effects of orifices on the engine oil circuit system.

• International Journal of Aeronautical and Space Sciences
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• 제9권1호
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• pp.100-110
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• 2008

It is not easy to monitor and identify all engine faults and conditions using conventional fault detection approaches like the GPA (Gas Path Analysis) method due to the nature and complexity of the faults. This study therefore focuses on a model based diagnostic method using Neural Network algorithms proposed for fault detection on a turbo shaft engine (PW 206C) selected as the power plant for a tilt rotor type unmanned aerial vehicle (Smart UAV). The model based diagnosis should be performed by a precise performance model. However component maps for the performance model were not provided by the engine manufacturer. Therefore they were generated by a new component map generation method, namely hybrid method using system identification and genetic algorithms that identifies inversely component characteristics from limited performance deck data provided by the engine manufacturer. Performance simulations at different operating conditions were performed on the PW206C turbo shaft engine using SIMULINK. In order to train the proposed BPNN (Back Propagation Neural Network), performance data sets obtained from performance analysis results using various implanted component degradations were used. The trained NN system could reasonably detect the faulted components including the fault pattern and quantity of the study engine at various operating conditions.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.22-24
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• 2008

This paper presents a numerical model of internal flows in a lubricant supplying and scavenging flow path of an aero-engine lubrication system. The numerical model was built in the General Analysis Software of Aero-engine Lubrication System, GASLS, developed by Northwestern Polytechnical University. The lubricant flow flux, pressure and temperature distribution at steady state were calculated. GASLS is a general purpose computer program employed a 1-D steady state network algorithm for analyzing flowrates, pressures and temperatures in a complex flow network. All kinds of aero-engine lubrication systems can be divided into finite correlative typical elements and nodes from which the calculation network be developed in GASLS. Special emphasis is on how to use combined elements which is a type of typical elements to replace some complex components like bearing bores, accessory gearboxes or heat exchangers. This method can reduce network complexity and improve calculation efficiency. Final computational results show good agreement with experimental data.

• 한국항공운항학회지
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• 제22권1호
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• pp.1-6
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• 2014

In this paper, controller propose to prevent compressor surge and improve the transient response of the fuel flow control system of turbojet engine. Turbojet engine controller is designed by applying Artificial Neural Network PID control algorithm and make an inference by applying Levenberg-Marquartdt Error Back Propagation Algorithm. Artificial Neural Network inference results are used as the fuel flow control inputs to prevent compressor surge and flame-out for turbojet engine for UAV. High Gain Observer is used to estimate to compressor rotation speed of turbojet engine. Using MATLAB to perform computer simulations verified the performance of the proposed controller. Response characteristics pursuant to the gain were analyzed by simulation.

• 제어로봇시스템학회논문지
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• 제18권1호
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• pp.13-20
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• 2012

This paper proposes a marine engine state monitoring system using a DPQ (Distributed Precedence Queue) mechanism which collects the state of bearings, temperature and pressure of engine through the CAN network. The CAN is developed by Bosch Corp. in the early 1980' for automobile network. The data from various sensors attached in the marine engine are converted to digital by the analog to digital converter and formatted to fit the CAN protocol at the CAN module. All the CAN modules are connected to the SPU (Signal Processing Unit) module for the efficient communication and processing. This design reduces the cost for wiring and improves the data transmission reliability by recognizing the sensor errors and data transmission errors. The DPQ mechanism is newly developed for the performance improvement of the marine engine system, which is demonstrated through the experiments.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 한국컴퓨터종합학술대회논문집 Vol.34 No.1 (A)
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• pp.145-148
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• 2007

Although the embedded network-engine is a demand of time, it is observed that up to this time the network-engines are not sufficient to control the input and output device for Video On Demand (VOD). In this paper we have proposed the wireless network-engine with the capability of controlling the input and output device.

• 한국게임학회 논문지
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• 제7권2호
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• pp.101-112
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• 2007

모바일 기술의 발전에 따라 모바일 게임도 다운로드 방식 게임에서 대규모 사용자들이 모바일폰을 이용하여 서버에 접속한 상태에서 실시간으로 진행하는 모바일 네트워크 게임(Mobile Network Game)으로 변하고 있다. 이러한 모바일 네트워크 게임을 경제적으로 개발하기 위해서는 이에 적절한 모바일 네트워크 게임 엔진이 필요하게 된다. 본 논문은 모바일 네트워크 게임을 개발하는데 필요한 실시간 무선 다중사용자 온라인 게임 엔진(RWMMO-GE : Realtime Wireless Massively Multiplayer Online RPG Game Engine)에 대한 설계 및 구현 결과를 제시한다. 본 논문의 연구 결과인 RWMMO-GE의 구조는 Network/Client Module, Object Module, Map Tool, Script Editor, Character Editor를 중요한 요소로 하여 이루어진다. 이러한 엔진을 활용하여 제작된 다중사용자 모바일 네트워크 게임의 특징은 모바일폰을 가진 대규모 사용자들이 하나의 맵에서 실시간으로 게임을 진행할 수 있다는 것이며, 이는 모바일 게임에서 새로운 비즈니스 모델이 가능함을 의미한다.

• Tribology and Lubricants
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• 제30권6호
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• pp.356-363
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• 2014

Marine diesel engines operate in environments in which damage easily occurs from corrosion. Recently, damage to cylinder liners has increased from corrosion wear caused by increased engine power. This damage can cause serious problems in the economy. Thus, many researchers have treated and studied damaged cylinder liners. However, a method is necessary for real-time monitoring of damage to cylinder liners during operation of the engine, before serious damage can occur. This study carries out reciprocating friction and wear tests on a cast iron specimen under various corrosion atmospheres and verifies the variations of friction coefficient and friction surface. Additionally, the friction coefficient and friction status are predicted by using a neural network that learns the vibration and frequency spectrum data from an acceleration sensor. According to our conclusions, amplitude is distributed highly at high frequencies, and values of standard deviation and kurtosis are high when damage to the friction surface is serious. The accuracy rate of the friction coefficient predicted by the neural network is over 80% of the real measured value without NaCl, and application of the neural network is very effective for diagnosing the friction condition and damage to the cylinder liner.

• Tribology and Lubricants
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• 제20권1호
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• pp.27-32
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• 2004

This paper presents unsteady oil flow behaviors in the engine lubrication network to clarify the differences between continuous and discontinuous oil supply crankshaft system. Using commercial network analysis program, Flowmaster2, engine lubrication network system analysis were carried out. And effects of crankshaft speed and supplied oil pressure on pressure fluctuation in oil groove and oil flow rate to each bearing were analyzed.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.29-34
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• 2002

This study presents the process of the continuous-time system identification for unknown nonlinear systems. The Radial Basis Function(RBF) error filtering identification model is introduced at first. This identification scheme includes RBF network to approximate unknown function of nonlinear system which is structured by affine form. The neural network is trained by the adaptive law based on Lyapunov synthesis method. The identification scheme is applied to engine and the performance of RBF error filtering Identification model is verified by the simulation with a three-state engine model. The simulation results have revealed that the values of the estimated function show favorable agreement with the real values of the engine model. The introduced identification scheme can be effectively applied to model-based nonlinear control.