• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.9
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• pp.1019-1025
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• 2014

Recently, the studies of the Unmanned Aerial Vehicle(UAV) has been studied a variety from military aircraft to civilian aircraft and for general hobby activity aircraft. In particular, for small unmanned aircraft research for the ease of turning and hovering and Vertical-Off Take Landing(VTOL), have been studied mainly quadrotor unmanned aircraft is a type suitable for this study of small unmanned aircraft. The studies of these unmanned aircraft is the kinetic analysis requires complex processes, because these support by the aerodynamic forces on the unmanned aircraft study, and the controller design based on these dynamical analysis and experimental model analysis. In this paper, after the implementation of the basic attitude control based on a general PID controller, we propose concept design of the attitude control method on quadrotor attitude control by using the reinforcement learning algorithm of neural networks for non-linear elements not considered in the controller design.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1509-1513
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• 2003

The autopilot system of vessel is proposed to take service safety and security, to elevate service efficiency, to decrease labor and to improve working environment. Ultimate purpose of the proposed system is to minimize the number of crew by guaranteeing economical efficiency of shipping service. Recently, the research is being achieved to compensate various nonlinear parameters of vessel and apply it to course keeping control, track keeping control, roll-rudder stabilization, dynamic ship positioning and automatic mooring control etc. using optimizing control technique. Relation between rudder angle controlled by steering machine of vessel and ship-heading angle, and load condition of ship is nonlinear, which affects various parameters of shipping service. The speed and direction of waves, velocity and quantity of wind, which also cause the non-linearity of it. Therefore the autopilot system of ship requires the robust control algorithm can overcome various non-linearity. On this paper, we design the autopilot system of ship, which overcomes nonlinear Parameters and disturbance of it using Fuzzy Algorithm, evaluate the proposed algorithm and its excellence through simulation.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.439-440
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• 2004

전력시스템의 부하주파수제어는 전력계통운용에 있어서 가장 중요하게 다루어야 한다. 본 논문에서는 강인한 퍼지제어기를 얻고자, 다층 신경회로망을 이용하여 퍼지제어기 멤버쉽 함수의 전건부 및 후건부 파라미터들을 시스템에 알맞게 자기 조정하기 위해 최급구배법에 근거한 오차 역전파 알고리즘으로 적응 학습시킬 수 있는 뉴로-퍼지제어기의 구조 및 알고리즘을 제안하였다.

• Journal of the KSME
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• v.34 no.4
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• pp.277-284
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• 1994

퍼지이론은 1965년 Lefti Zadeh 교수에 의해 처음으로 제창되었으며 여러 분야에서 응용이 확 대되어 많은 좋은 성과를 얻고 있다. 그러나 전문가 시스템의 일종인 퍼지논리를 이용한 제어는 제어를 하고자 하는 시스템의 정성적인 특성에 대한 법칙의 추출이 어려운 문제로 남아 있다. 반면에 신경회로망을 이용한 제어는 스스로 지식을 축적할 수 있는 장점을 갖고 있으므로 최근에 많은 연구가 진행중에 있다. 특히 제어분야에서는 용접공정이나 조립공정 등의 공정제어와 로 봇제어의 분야에 이르기까지 응용분야가 확대되고 있다. 이 글에서는 이러한 인공지능 기법을 생산공정의 자동화에 적용한 사례 연구를 통해 이 기법의 유용함을 살펴보기로 한다.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.312-316
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• 1987

A simple hybrid circuit to control the two-phase AC motor of the nut-runners which employ the tightening torque control system is described in this paper. The circuit has emphasis on the low-cost implementation. The circuit constitutes of the V/F converter using a timer IC, the pulse width modulator using the fastening torque signal and the two-phase logic sequencer.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.2
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• pp.28-37
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• 1999

Differentially Responsible Adaptive Critic Learning technique is proposed for learning the control technique with multiple control inputs as in robot system using reinforcement learning. The reinforcement learning is a self-learning technique which learns the control skill based on the critic information Learning is a after a long series of control actions. The Adaptive Critic Learning (ACL) is the representative reinforcement learning structure. The ACL maximizes the learning performance using the two learning modules called the action and the critic modules which exploit the external critic value obtained seldomly. Drawback of the ACL is the fact that application of the ACL is limited to the single input system. In the proposed Differentially Responsible Action Dependant Adaptive Critic learning structure, the critic function is constructed as a function of control input elements. The responsibility of the individual control action element is computed based on the partial derivative of the critic function in terms of each control action element. The proposed learning structure has been constructed with the CMAC neural networks and some simulations have been done upon the two dimensional Cart-Role system and robot squatting problem. The simulation results are included.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.11
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• pp.1274-1281
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• 1988

A new voltage-controlled oscillator based on a voltage-controlled integrator has been developed. It consists of a Schmitt-trigger and a voltage-controlled integrator, which is realized by an operational transconductance amplifier (OTA) and a grounded capacitor. The input control voltage changes the time constant of the integrator, and hence the oscillation frequency. The SPICE simulation shows that a prototype circuit, which oscillates at 12.21 KHz at 0 V, has the conversion sencitivity 2,437 Hz/V and the residual nonlinearity less than 0.68% in a control voltage range from -2 V to 2 V. It also shows that the circuit provides a temperature drift less than + 250 ppm/$^{\circ}$C for frequencies up to 100 KHz.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.503-512
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• 2020

The products using blowers include hand dryers, automatic car washers, dryers, and vacuum cleaners. The features of these products require a structure and control algorithm so that a strong wind is blown out at the moment. Electric motors according to the existing excitation method include a direct winding type, a decentralized type, a lottery type, and a permanent magnet type. Conventional electric motors have a disadvantage when the starting current is large during high-speed rotation and the number of rotations is irregular. In order to improve this, research on high-speed BLDC motor control has designed 800W-class high-speed BLDC motor control and circuit through driving circuit design, sensorless control algorithm, simulation, experiment, etc., and more than 95% high efficiency evaluation method of driving performance of controller, prototype experiments and verification were studied.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.5
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• pp.395-400
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• 2000

In this paper, we propose a new neuro-fuzzy controller based on reinforcement learning. The proposed system is composed of neuro-fuzzy controller which decides the behaviors of an agent, and dynamic recurrent neural networks(DRNNs) which criticise the result of the behaviors. Neuro-fuzzy controller is learned by reinforcement learning. Also, DRNNs are evolved by genetic algorithms and make internal reinforcement signal based on external reinforcement signal from environments and internal states. This output(internal reinforcement signal) is used as a teaching signal of neuro-fuzzy controller and keeps the controller on learning. The proposed system will be applied to controller optimization and adaptation with unknown environment. In order to verifY the effectiveness of the proposed system, it is applied to collision avoidance of an autonomous mobile robot on computer simulation.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.108-116
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• 2003

This research presents the design and analysis of PCDU(Power Control & Distribution Unit) of communication satellite. The PCDU of a spacecraft must provide adequate power to each subsystem and payload during mission life, and it also needs high reliability and performance in space environment. A control circuit of the PCDU include bus sensing and filter circuits, error signal amplification circuit, error compensation circuit of SAS(Shunt Assembly Switch) and BPC(Battery Power Converter). The phase margin and DC gain for the designed circuits are analyzed through the frequency response characteristics of the compensated control circuit. And also the transfer function of the battery power converter circuit are discussed at the battery CCCM(Charge Continuous Conduction Mode) and battery C/DCCM(Continuous/Discontinuous Conduction Mode).