• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.381-384
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• 2001

본 논문에서는 간단한 외란 관측 기법을 이용한 영구자 석형 동기 전동기(Permanent Magnet Synchronous Motor: PMSM)의 비선형 속도 제어 기법이 제안된다. 피드백 선형화 (feedback linearization) 기법을 이용함으로써 비선형 요소가 효과적으로 제거되고 출력 오차 동특성을 선형 제어 기법에 기반 하여 설정할 수 있다. 그리고 파라미터 변동에 의한 비선형 외란을 제거하기 위해 본 논문에서는 외란 관측 기법을 이용한다. 제안한 관측기를 이용한 비선형 속도 제어 알고리즘이 파라미터 변동에 대해 강인한 제어 특성을 가짐을 시뮬레이션으로 확인하였다.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.2
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• pp.113-118
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• 2007

In this paper, a novel approach to using Subcircuit of Pspice in designing feedback for DC-DC converter systems is proposed. Proposed new approach, the feedback design procedures which are based on small signal modeling are programmed as a subcircuit in Pspice. For this purpose, Analog Behavioral Modeling (ABM) is used. By using the subcircuit, the component values of the error compensation amplifier can be easily obtained by means of Pspice DC analysis. The methodology of development is presented in detail and application examples demonstrated the effectiveness of the proposed approach in designing feedbacks for DC-DC converters. The converter with PWM method used continuous current mode and calculated buck converter control signal with average and linear current technique. To decide pole and zero K-method was adapted and this kind of design procedure took stable function.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.4
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• pp.308-315
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• 2016

This paper addresses a formation control problem for a phugoid model-based multi-agent system in discrete time by using a Takagi-Sugeno (T-S) fuzzy model-based controller design technique. The concerned discrete-time model is obtained by Euler's method. A T-S fuzzy model is constructed through a feedback linearization. A fuzzy controller is then designed to stabilize the T-S fuzzy model. Design condition is presented in the linear matrix inequality format.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.2
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• pp.149-157
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• 2001

A nonlinear speed control for a permanent magnet synchronous motor (PMSM) using a simple disturbance estimation technique is presented. By using a feedback linearization scheme, the nonlinear motor model can be linearized in a controllable canonical form, and the desired speed dynamics can be obtained based on the linearized model. This technique, however, gives an undesirable output performance under the mismatch of the system parameters and load conditions. To cancel disturbance by parameter variation, the controller parameters will be estimated by using a disturbance observer theory where the disturbance torque and flux linkage are estimated. since only the two reduced order observers are used for the parameter estimations, the observer designs are considerably simple and the additional load for computation of the controller is negligibly small. The proposed control scheme is implemented on a PMSM using DSP TMS320C31 and the effectiveness is verified through the comparative simulations and experiments.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.3
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• pp.41-49
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• 2010

Two promising control candidates have been selected to test the sinusoidal reference tracking performance for a brush-type polishing machine having strong nonlinearities and disturbances. The controlled target system is an oscillating mechanism consisting of a common positioning stage of one degree-of-freedom with a screw and a ball nut driven by a servo motor those can be obtained commercially. Beside the strong nonlinearity such as stick-slip friction, the periodic contact of the polishing brush and the work piece adds an external disturbance. Selected control candidates are a Sliding Mode Control (SMC) and a variant of a feedback linearization control called Smooth Robust Nonlinear Control (SRNC). A SMC and SRNC are selected since they have good theoretical backgrounds, are suitable to be implemented in a digital environment and show good disturbance and modeling uncertainty rejection performance. It should be also noted that SRNC has a nobel approach in that it uses the position information to compensate the stickslip friction. For both controllers analytical and experimental studies have been conducted to show control design approaches and to compare the performance against the strong nonlinearity and the disturbances.

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.56-64
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• 2013

Crabbing motion is the pure sway motion of a ship without surge velocity. Thus, it can be applied to a berthing operation. Crabbing motion is induced by a peculiar operation method called the push-pull mode. The push-pull mode is induced by using a combination of the main propeller and side thruster. Two propellers generating the same amounts of thrust and rotating in opposite directions produce some yawing moment on a vessel but do not induce longitudinal motion. With the additional operation of side thrusters, the push-pull mode is used to induce a large amount of lateral force. In this paper, three-degree-of-freedom equations of motion such as for the surge, sway, and yaw are constructed for the crabbing motion. Based on these equations of motion, a feedback linearization control method is applied to auto-berthing control for a twin-screw ship with side thrusters. The controller can deal with the nonlinearity of a system, which is present in the berthing maneuver of a twin screw ship. A simulation of the auto-berthing of a ship is performed to validate the performance of the designed controller.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.297-303
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• 2015

We propose a disturbance observer(DOB) based feedback linearization control to improve position tracking performance in the presence of disturbance. The proposed method consists of a disturbance observer and a feedback linearization controller. The disturbance observer is designed to estimate the load force disturbance in electro-hydraulic systems. An auxiliary state variable is proposed in order to avoid amplification of the measurement noises in the disturbance observer. Using the estimated disturbance enables the Electro-hydraulic servo systems(EHS) dynamics to be changed into feedback linearization from. In order to compensate for the disturbance and to track the desired position, the feedback linearization based controller is proposed. The proposed method has a simple structure which can easily be implemented in practice. As a result, the proposed method improves the position tracking performance in the presence of disturbance. Its performance is validated via simulations.