• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.53-55
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• 1988

The application of Sliding Mode Control for inproving the dynamic response of a Multi-Phase-Bipolar (MPB) Brushless DC motor based position Brushless DC motor system is presented. Sliding Mode Control gives fast dynamic response with no overshoot and zero steady state error. It has the important feature of bins highly robust. A design procedure is outlined for the Sliding Mode Controller for a MPB Brushless DC motor. Digital computer simulation of the overall position control system is carried out using a time domain model in the d-q reference frame.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.257-260
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• 2003

스마트 무인기용 터보제트 엔진의 동적 성능모사 프로그램을 개발하였다. 천이 성능 프로그램에는 일정공기유량(Constant Mass Plow) 방법을 적용되었으며 잉여토크의 적분에는 오일러 적분법을 이용하였다. 천이성능해석은 가스발생기의 아이들로부터 최대 회전수까지 증가하는 것을 수행하였다. 엔진의 동적거동을 살펴보기 연료유량을 step과 ramp 증가로 주었다. 연료가 step으로 증가되었을 때 터빈 입구온도에서 오버슈트가 발생하였으며 연료유량을 0.6sec 이상으로 증가시켰을 때 오버슈트가 제거됨을 확인할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.907-912
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• 1990

An approach to robot force control, which allows force manipulations to be realized without overshot and overdamping while in the presence of unknown environment, is given in this paper. The main idea is to use dynamic compensation for known robot parts and fuzzy compensation for unknown environment so as to improve system performance. The fuzzy compensation is implemented by using rule based fuzzy approach to identify unknown environment. The establishment of proposed control system consists of following two stages. First, similar to the resolved acceleration control method, dynamic compensation and PID control based on known robot dynamics, kinematics and estimated environment compliance is introduced. To avoid overshoot the whole control system is constructed overdamped. In the second stage, the unknown environment stiffness is estimated by using fuzzy reasoning, where the fuzzy estimation rules are obtained priori as the expression of the relationship between environment stiffness and system response. Based on simulation result, comparisons between cases with or without fuzzy identifications are given, which illustrate the improvement achieved.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.558-562
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• 2000

This research is concerned with the experiments on buckling characteristics of strain energy hinge(SEH) for solar arrays. The dynamic characteristics of the strain energy hinge is very important since it affects the shape and speed of the solar array deployment. The rapid deployment results in overshoot and undesirable residual vibrations. In this study, we carry out a series of buckling experiments to identify the dynamic characteristics of the SEH, which is made of strip measures. Buckling tests were done on the single-plate, double-plate and triple-plate SEH and VSEH. The experimental results show that the SEH has a very complex buckling behavior which can not be coped with theoretically. The modeling problem of the SEH is also discussed.

• 전기학회논문지
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• 제61권2호
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• pp.303-311
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• 2012

In this study, we introduce a dynamic process model as well as the design methodology of optimized fuzzy controller for its efficient application to vacuum production system to produce a semiconductor, solar module and display and so on. In a vacuum control field, PID control method is widely used from the viewpoint of simple structure and preferred performance. But, PID control method is very sensitive to the change of environment of control system as well as the change of control parameters. Therefore, it's difficult to get a preferred performance results from target system which has a complicated structure and lots of nonlinear factors. To solve such problem, we propose the design methodology of an optimized fuzzy PID controller through a following series of steps. First a dynamic characteristic of the target system is analyzed through a series of experiments. Second the process model is built up and its characteristic is compared with real process. Third, the optimized fuzzy PID controller is designed using genetic algorithms. Finally, the fuzzy controller is applied to target system and then its performance is compared with that of other conventional controllers(PID, PI, and Fuzzy PI controller). The performance of the proposed fuzzy controller is evaluated in terms of auto-tuned control parameters and output responses considered by ITAE index, overshoot, rise time and steady state time.

• 한국항행학회논문지
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• 제16권4호
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• pp.571-577
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• 2012

본 논문에서는 소형 무인항공기에 대한 비행제어 시스템을 동적 보상기를 이용하여 설계하였다. 제안된 제어 시스템은 정상상태 오차를 줄이면서 과도응답 특성을 개선하여 고도 변화 및 목표점 통과 명령에 대해 비행 안정성을 확보하고자 하였다. 제안된 비행 제어기는 내부 루프와 외부 루프의 이중 구조로 구성되며, 내부 루프는 PD 제어기를 사용하여 과도응답을 개선하도록 하며 외부 루프는 동적 보상기를 사용하여 과도 응답 및 정상 상태 오차를 개선하도록 하였다. 고도 추종 및 목표점을 통과하도록 하는 비행실험을 통하여 제안된 기법의 성능을 평가하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.45-46
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• 2006

In this paper, a dual stage servo mechanism has been developed for image tracking system to improve transient control performances such as small rise time, small overshoot, small settling time, etc. A secondary stage, a platform, actuated by a pair of electro-magnets is mounted on a conventional elevation gimbal. In this mechanism, the gimbal provides large range but slow motion and the platform provides small range but fast positioning. A sliding mode control is applied to the platform positioning to attain robust performances and stability in the presence of the disturbance related to dynamic coupling of the gimbal and the platform. Results from experiments illustrate that the suggested dual stage mechanism controlled by the sliding mode control is effective in improving transient responses and attenuating the disturbance related with dynamic coupling.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.499-505
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• 2004

A Propulsion System of the CRW(Canard Rotor Wing) type UAV(Unmanned Aerial Vehicle) was composed of the turbojet engine to generate the propulsive exhaust gas, and the duct system including straight bent ducts, tip-jet nozzles, a master valve and a variable main nozzle for three flight modes such as lift/landing mode, low speed transition flight mode and high speed forward flight mode. In this study, in order to operate safely the propulsion system, the dynamic Performance behavior of the system was modeled and simulated using the SIMULIN $K^{ }$, which is the user-friendly GUI type dynamic analysis tool provided by MATLA $B^{ }$. In the transient performance model, the inter-component volume model was used. The performance analysis using the developed models was performed at various flight condition, valve angle positions and fuel flow schedules, and these results could set the safe flight mode transition region to satisfy the inlet temperature overshoot limitation as well as the compressor surge margin. Performance analysis results using the SIMULIN $K^{ }$ performance program were compared with them using the commercial program GSP.m GSP.

• Journal of Power Electronics
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• 제15권1호
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• pp.160-176
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• 2015

This paper presents a method of designing optimal integer- and fractional-order proportional-integral-derivative (FOPID) controllers for a boost converter to gain a set of favorable characteristics at various operating points. A Pareto-based multi-objective optimization approach called strength Pareto evolutionary algorithm (SPEA) is used to obtain fast and low overshoot start-up and dynamic responses and switching stability. The optimization approach generates a set of optimal gains called Pareto set, which corresponds to a Pareto front. The Pareto front is a set of optimal results for objective functions. These results provide designers with a trade-off look-up table, in which they can easily choose any of the optimal gains based on design requirements. The SPEA also overcomes the difficulties of tuning the FOPID controller, which is an extension to the classic integer-order PID controllers and potentially promises better results. The proposed optimized FOPID controller provides an excellent start-up response and the desired dynamic response. This paper presents a detailed comparison of the optimum integer- and the fractional-order PID controllers. Extensive simulation and experimental results prove the superiority of the proposed design methodology to achieve a wide set of desired technical goals.

• 항공우주시스템공학회지
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• 제15권1호
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• pp.47-55
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• 2021

항공기의 비정상적인 착륙 상황에서도 조종사의 생존을 보장하고 탈출에 방해되지 않도록 구조물이 설계되어야 한다. 추락 시, 화재의 원인을 찾는 연구를 시작으로 과거 수많은 고정익 항공기 추락시험이 수행되었다. 동역학적 분석을 통한 구조물의 거동특성을 이해하고, 가속도 상태에서 인체의 허용한계를 조사하여 적절한 추락하중배수가 설정되었다. 또한 화물기 사고 데이터를 확률론적 방법으로 분석하여 승객의 안전과 운용비용이 합리적으로 반영된 화물고정용 추락하중배수도 제시되었다. 과거 사례를 바탕으로 현재 적용되고 있는 추락하중배수의 물리적, 의학적, 경제적 의미를 살펴 보았다.