• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.82-97
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• 2009

In this study, a linearlized model of liquid rocket engine specifically for the gasgenerator cycle one was developed to serve as a basic control model. A commercial software Simulink was used for the modeling. Using this tool we studied the throttling characteristic of engine around its nominal mode. To obtain the effect of the throttle valve design on the engine's control characteristic, we included mathematical model of the control valve with driving motor and the pressure stabilizer which installed on the gas-generator fed line to sustain the mixture ratio of the gas-generator.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.71-81
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• 2001

This paper analyzes the effectiveness of minimizing vibration and sound transmission on/through a thin rectangular plate by both feedback control and hybrid control which combines adaptive feedforward control with a feedback loop. An experimental system identification technique using the matrix-fractional curve-fitting of the frequency response data is introduced for complex shaped structures. This identification technique reduces the model order o the MIMO(Multi-Input Multi-Output) system which simplifies the practical implementation. The adaptive feedforward control uses a Multiple filtered-x LMS(Least Mean Square) algorithm and the feedback control uses a multivariable digital LQG(Linear Quadratic Gaussian) algorithm. Experimental results show that an effective reduction of sound transmission is achieved by the hybrid control scheme when both vibration and noise measurement signals are incorporated in the controller.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.12
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• pp.1218-1225
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• 2008

This paper presents the design of a neural network based adaptive control for missile is presented. The application model is Exocet MM40, which is derived from missile DATCOM database. Acceleration of missile by tail Fin control cannot be controllable by DMI (Dynamic Model Inversion) directly because it is non-minimum phase system. So, the inner loop consists of DMI and NN (Neural Network) and the outer loop consists of PI controller. In order to satisfy the performances only with PI controller, it is necessary to do some additional process such as gain tuning and scheduling. In this paper, all flight area would be covered by just one PI gains without tuning and scheduling by applying mixture control technique of conventional controller and NN to the outer loop. Also, the simulation model is designed by considering non-minimum phase system and compared the performances to distinguish the validity of control law with conventional PI controller.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.394-395
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• 2018

본 논문에서는, 직류단 1-션트 전류 측정을 이용하는 고속 BLDC 전동기 운전 시스템의 제어 성능 향상 및 전류 측정 영역 확장을 위한 제어 방법을 제안한다. 고속 BLDC 전동기의 PWM 기법과 그에 따른 직류단 1-션트 전류 측정 방법 및 측정 영역을 분석하고, 측정 가능 범위를 수식적으로 정리한다. 제안된 제어 방법은 전류 맥동 감소 및 고속 운전 정밀도 향상에 적합한 PWM 기법과 직류단 1-션트 전류 측정 범위가 넓은 PWM 기법을, 정리된 수식을 바탕으로 운전 영역에 따라 사용하여 제어 성능을 향상 시킨다. 계산 데이터 및 실험 결과를 통해 제안된 방법의 효용성을 확인한다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.5
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• pp.19-27
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• 2004

A delay dependent fuzzy $H_2/H_{\infty}$ controller design method for delayed fuzzy dynamic systems is considered. Using delay-dependent Lyapunov function, the asymptotical stability and $H_2/H_{\infty}$ performance problem are discussed. A sufficient condition for the existence of fuzzy controller is presented in terms of linear matrix inequalities(LMIs). A simulation example is given to illustrate the design procedures and performances of the proposed methods.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.353-359
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• 1993

본 연구에서는 객체지향 개념과 분산형 문제해결 방법의 장점을 혼합한 FMS 생산현장통제 시스템을 제안하였다. 제안된 시스템은 FMS의 모든 구성요소를 지능적인 객체로써 표현하고, 객체들간의 Bidding 과정을 통하여 생산 현장의 상태변화에 대응해 나가는 구조를 가지고 있다. 실험 결과, 제안된 시스템은 기존의 Dispatching rule에 비하여, job의 시스템내 체류시간이 감소하며 기계부하가 평준화되는 현상을 나타내었다.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.54-58
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• 1989

The purpose of this paper is to develop a more accurate attitude algorithm with low grade gyro output. The proposed algorithm estimates attitudes by combining accelerometer and gyro output. For performance improvement of the algorithm, a method of velocity compensation is proposed for a better attitude estimation which is calculated from the accelerometer output. Velocity compensation is done by using Kalman Filter to estimate another velocity component.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.233-233
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• 2009

기존 표면열처리기술에 단점인 대면적, 신속열처리를 위해 수중플라즈마 기술을 이용하여 표면경화와 경화 깊이층 제어를 실시였다. 수중플라즈마의 전원장치에 전압과 주기적인 전압과 시간을 달리하여 각각의 시편의 경도변화와 미세조직변화를 관찰하였다. 300V이상의 전압에서는 마르텐사이트가 관찰되었으며, 300V이하에서는 초석페라이트와 펄라이트가 혼합된상의 구조를 관찰할 수 있었다. 주기적인 전압과 시간을 달리하여 표면에서부터 $300{\mu}m$ 깊이만의 마르텐사이트로 형성시켜 경화 깊이층 제어가 가능하였다.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.145-145
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• 2000

In this paper, we propose a hybrid d-step predictor which is composed of an adaptive predictor and a Kalman predictor. We prove the performance limit of the proposed predictor. Simulation is conducted to examine the performance of the proposed predictor. Simulation results show that the proposed combined predictor is superior to the adaptive predictor and the Kalman predictor. Proposed predictor is used for prediction of gun tip vibration of k1 tank. The result is compared with that of conventional adaptive predictor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.994-998
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• 1996

We propose an approach to integrating fuzzy logic control with RBF(Radial Basis Function) networks and show how the integrated network can be applied to multivariable self-organizing and self-learning fuzzy controller. Using the hybrid learning algorithm. To investigate its usefulness and performance, this controller is applied to a time-delayed process system. Simulation results show good control performance and fast convergency in hybrid loaming method.