• Journal of Mechanical Science and Technology
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• 제18권8호
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• pp.1312-1318
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• 2004

Roll stabilization systems for ships are employed to increase comfort for passengers, maintain full working capabilities for members of the crew and prevent cargo damage. In this paper, we have investigated the usefulness of active stabilizing system to reduce ship rolling under disturbances, using varied reaction of the flaps. In the proposed anti-rolling system for a ship, the flaps as the actuator are installed on the stern to reject rolling motion induced by disturbances such as wave. The action induced by flaps depends on power of disturbances and can take the ship balance. Especially, in this study we define the system parameters under the given system structure and design the controller to evaluate the usefulness of the proposed system.

• 펄프종이기술
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• 제35권3호
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• pp.1-12
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• 2003

The complexity of the papermaking system accelerates interactions between a large number of variables involved. The process operation, therefore, is subject to frequent perturbations by disturbance. Dynamic modelling is a useful tool for characterizing the transient behavior and selecting the best control strategies to reject disturbances. In this study we developed a dynamic simulation model of a fine paper production process, which consists of stock preparation, wire sections, white water circulations, and broke system. It focused on dynamic simulation in its role for developing control strategies and studying control loop dynamics related to filler loading for ash control. The results emphasized the importance of filler-loading position and length of control loop for rapid ash control and process stabilization.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.553-557
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• 1994

We propose a design method that uses H$_{\infty}$ optimization method to suppress oscillation of a shaft between motor and load for high precision (0.001 % of reference input) position controls. PI speed control loop was introduced as a minor loop. Standard problem is used for the modeling of the system and Glover-Doyle's algorithm is used for the optimization in the H$_{\infty}$ space. Friction is considered to be an important factor that makes it difficult for the system to reach steady state in short time. In this paper, we propose a hybrid controller that includes PI speed feedback loop, which is expected to have a role to reject torque disturbance like friction.n.n.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.956-959
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• 1996

In this study, we propose a neuro-genetic controller combined with a linear controller in parallel to improve the tracking performance of the Line of Sight(LOS) stabilization system and reject the effect of disturbances. A Genetic Algorithm(GA) is used to optimize weights of the neuro-genetic controller since this algorithm can search a global minimum without derivatives or other auxiliary knowledge. The LOS system is very complex and has limited measurable output data. Under these specific circumstances GA solves many problems that other training methods have. Computer simulation results show that the, proposed controller makes better tracking response and rejection of disturbance than a linear controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.841-843
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• 1999

This paper presents a design of stabilization controller for combat vehicle. A Stabilization system reject disturbances while vehicle moving. The conventional stabilization controller used to constant gain. We can improve the aiming performance by appropriate controller gain. We can find the proper controller gain for road frequencies by evolution strategy(ES). The relationship between the frequencies and proper control gains are generalized by use of the neural network. The road frequency estimated by wavelet transform of disturbance signal. The simulation result show that proposed controller is superior to the conventional stabilization controller.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 추계학술대회 논문
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• pp.150-155
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• 1996

This paper presents a new approach to the design of self-tuning adaptive control system that is robust to the changing dynamic configuration as well as to the load variation factors using digital signal processors for robot manipulators. TMS3200C50 is used in implementing real-time adaptive control algorithms provide advanced performance for robot manipulator. In this paper an adaptive control scheme is proposed in order to design the pole-placement self-tuning controller which can reject the offset due to any load disturbance without a detailed description of robot dynamics. parameters of discrete-time difference model are estimated by the recursive least-square identification algorithm and controller parameters are detemined by the pole-placement method. Performance of self-tuning adaptive controller is illusrated by the simulation and experiment for a SCARA robot.

• 동력기계공학회지
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• 제5권4호
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• pp.90-96
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• 2001

In this study, a robust controller to control pressure in a pneumatic pressure vessel considering dynamic characteristics of pneumatic transmission line is proposed. Dynamic characteristics of transmission line using compressible fluid is changed by the flowing states of the fluid. So, if the fixed gain controller is designed based on a fixed model, the performance of the control system could be destabilized or degraded. The controller designed in this study is composed of two parts. The one is to reject modelling error based on the disturbance observer, the other is to obtain the control performance. The control results with the designed controller show that the robustness of the control system is achieved regardless of the change of the model of the transmission line. Therefore, the designed controller can be utilized for the performance improvement of the pressure control system using compressible fluid such as air and gas

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.206-211
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• 2011

In this paper, a control algorithm for the improvement of yaw and velocity stability of electrical vehicle with two or four in-wheel motors is proposed. The vehicle is modeled with independently operative in-wheel motor wheels. Different frictions on the wheels are regarded as disturbances, which causes driving instability. In this situation the proposed algorithm enables stabilizing the yaw motion and velocity of vehicle simultaneously. The proposed PID controller is composed with two techniques, which enhance the disturbance reject and point tracking performances. One is nonlinear gain function and the other one is improved integral controller operating as time based weight function. Simulation is conducted to reveal its efficient performance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.831-836
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• 2011

The study described in this paper is aimed to maintain a constant output of wind turbine system via pitch control of wind turbine using Advanced PID(APID) controller. In order to improve dynamic response characteristic in terms of pitch angle and disturbance reject, the APID controller is developed. The structure of the APID is composed with derivative P controller and new type of integral control action. This new improved integral control has concept of error window and weight function concept. The performance of the APID control technique is compared with those of conventional ones via simulation. Simulation results show that the proposed method is effective and enhanced the dynamic performance of the system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.754-758
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• 1996

This paper presents a new approach to the design of self-tuning adaptive control system that is robust to the changing dynamic configuration as well as to the load variation factors using Digital signal processors for robot manipulators. TMS320C50 is used in implementing real-time adaptive control algorithms to provide advanced performance for robot manipulator, In this paper, an adaptive control scheme is proposed in order to design the pole-placement self-tuning controller which can reject the offset due to any load disturbance without a detailed description of robot dynamics. Parameters of discrete-time difference model are estimated by the recursive least-square identification algorithm, and controller parameters we determined by the pole-placement method. Performance of self-tuning adaptive controller is illusrated by the simulation and experiment for a SCARA robot.