• 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.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.129-132
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• 2002

The practical virtual compensator, which uses a dynamic multi-leaf collimator (dMLC) and three-dimensional radiation therapy planning (3D RTP) system, was designed. And the feasibility study of the virtual compensator was done to verify that the virtual compensator acts a role as the replacement of the physical compensator. Design procedure consists of three steps. The first step is to generate the isodose distributions from the 3D RTP system (Render Plan, Elekta). Then isodose line pattern was used as the compensator pattern. Pre-determined compensating ratio was applied to generate the fluence map for the compensator design. The second step is to generate the leaf sequence file with Ma's algorithm in the respect of optimum MU-efficiency. All the procedure was done with home-made software. The last step is the QA procedure which performs the comparison of the dose distributions which are produced from the irradiation with the virtual compensator and from the calculation by 3D RTP. In this study, a phantom was fabricated for the verification of properness of the designed compensator. It is consisted of the styrofoam part which mimics irregular shaped contour or the missing tissues and the mini water phantom. Inhomogeneous dose distribution due to the styrofoam missing tissue could be calculated with the RTP system. The film dosimetry in the phantom with and without the compensator showed significant improvement of the dose distributions. The virtual compensator designed in this study was proved to be a replacement of the physical compensator in the practical point of view.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.1066-1071
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• 1992

A new scheme of OFVSC(Output Feedvack Variable Structure Controller) is proposed for the servo control system. The main structure of proposed control scheme is composed of servo compensator and dynamic switiching function. By the use of dynamic switiching function the assumption of full state availability can be removed and the disturbances which does not satisfy the matching condition cna be rejected. And the servo compensator which is designed for each output variable the robustness for the all type of disturbances. And the performances of proposed control system are evaluated through simulation studies for a numerical example.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.539-545
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• 2001

This paper proposes a static synchronous series compensator based on multi-bridge inverter. The proposed system consists of 6 H-bridge modules per phase, which generate 13 pulses for each half period of power frequency. The dynamic characteristic was analyzed by simulations with EMTP code, assuming that it is inserted in the 154-kV transmission line of one-machine-infinite-bus power system. The feasibility of hardware implementation was verified through experimental works using a scaled model. The proposed system does not require a coupling transformer for voltage injection, and has flexibility in expanding the operation voltage by increasing the number of H-bridge modules.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.66-69
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• 2008

In this paper, The author present a load current feed-forward compensator by method that improve voltage controller of Step-down Chopper to get stable output voltage to sudden change of load current. To confirm the characteristicsof a presented load current feed -forward compensator compared each transfer function of whole system that load current feed-forward compensator is added with transfer function of whole system that existent voltage controller is included using Mason gains formula in Root locus and Bode diagram. As a result the pole of system is improved, extreme point of the wave and system improves, and size of peak value and phase margin of break frequency in resonance frequency confirmed that is good. Therefore, presented control technique could confirm that reduce influence by perturbation and improves stationary state and dynamic characteristics in output of Step-down Chopper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 학술대회 논문집 전문대학교육위원
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• pp.108-111
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• 2007

A novel voltage sag compensator with hi-directional DC/DC converter of Electric double layer capacitor is proposed. Recently, the double-layer capacitor which is drawn attention as a new energy storage element has a lot of advantage such as no maintenance, long lifetime and quick charge/discharge characteristics with large current. This DC/DC converter is used to control the charging current to the double-layer capacitor and also used to keep the DC link voltage constant for discharge of the double-layer capacitor. Therefore, the proposed DC/DC converter has the high-efficiency controller, dynamic compensator of voltage sag is driven by this converter. Finally, experimental results show the validity of the control scheme and the ability of the dynamic voltage compensator.

• 한국정보통신학회논문지
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• 제18권3호
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• pp.503-509
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• 2014

본 논문에서는 이동 로봇의 군집 제어를 위해 실시간 적응 신경 회로망 보상기를 갖는 PID 제어기를 제안한다. 전체 제어 시스템은 선도-추종 로봇 접근법에 의한 기구학 제어기와 이동 로봇의 동역학을 고려한 동적 제어기로 구성되어 있다. 동적 제어기는 PID 제어기에 동특성 변화를 보상하고 성능을 개선시키기 위해 실시간 학습 기능을 가진 신경 회로망 보상기로 구성하였다. 모의실험을 통해 원형 궤적과 직선 궤적에 대해 PID 제어기와 신경 회로망 보상기의 성능을 비교하였다. 이를 통해 실시간 학습 기능을 가진 신경 회로망 보상기가 PID 제어기의 성능을 향상시킴으로써 군집 제어에서 추종 로봇의 추종 성능을 향상시키는 것을 확인하였다.

• 제어로봇시스템학회논문지
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• 제16권7호
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• pp.688-694
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• 2010

This paper presents a gravity compensator for the manipulator of a service robot. The manipulator of a service robot is operated with low velocity for the safety reason in most cases. In this situation gravitational torques generated by the mass of links are often much greater than dynamic torques for motion. A gravity compensator can counterbalance the gravitational torques, thereby enabling to utilize relatively low power motors. In this paper the gravity compensation for the roll-pitch rotation is considered which is often used for the shoulder joints of the manipulator of a service robot or humanoid robot. A gimbals is implemented and two 1-dof gravity compensators are equipped at the base. One compensates the gravitational torque at the roll joint and another provides the compensational torque for the gimbals. Various analyses showed that the proposed compensator can counterbalance the gravitational torques of 87% at the pitch joint and 50% at the roll joint. It is verified from dynamic simulations that the proposed compensator effectively counterbalances the gravitational torques.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.299-302
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• 1997

This paper describes a dynamic var compensator to compensate the line reactance for power transmission and distribution system. The compensator consists of a voltage source inverter with dc capacitor, coupling transformers, and control circuit. The operation of compensator was verified by computer simulations with EMPT and experimental works with a scaled hardware model. The advantage of the proposed system is rapid and continuous regulation of the reactive power.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.680-683
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• 1999

A thyristor controlled shunt compensator, which is installed in the middle of the transmission line is adopted for controlling real power flow in a simple power transmission system. By means on the Fourier series representation of the thyristor switching action and the system parameters, the thyristor current equations are derived, which transmit the required real power of the simple power transmission system and inform the thyristor firing angle, the thyristor conduction angle, the power flows and the harmonic characteristics EMTP simulations at the various operating points show the dynamic characteristics of the thyristor controlled shunt compensator and correspond to the results calculated with the Fourier series representation.