• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.407-422
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• 2004

A new method for the design of predictive controllers for SISO systems is presented. The proposed technique allows uncertainties and constraints to be concluded in the design of the control law. The goal is to design, at each sample instant, a predictive feedback control law that minimizes a performance measure and guarantees of constraints are satisfied for a set of models that describes the system to be controlled. The predictive controller consists of a finite horizon parametric-optimization problem with an additional constraint over the manipulated variable behavior. This is an end-constraint based approach that ensures the exponential stability of the closed-loop system. The inclusion of this additional constraint, in the on-line optimization algorithm, enables robust stability properties to be demonstrated for the closed-loop system. This is the case even though constraints and disturbances are present. Finally, simulation results are presented using a nonlinear continuous stirred tank reactor model.

• International Journal of Control, Automation, and Systems
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• v.4 no.5
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• pp.660-667
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• 2006

This paper presents a novel region-based snake method for vessel segmentation. According to geometric shape analysis of the vessel structure with different scale, an efficient statistical estimation of vessel branches is introduced into the energy objective function, which applies not only the vessel intensity information, but also geometric information of line-like structure in the image. The defined energy function is minimized using the gradient descent method and a new region-based speed function is obtained, which is more accurate to the vessel structure and not sensitive to the initial condition. The narrow band algorithm in the level set framework implements the proposed method, the solution of which is steady. The segmentation experiments are shown on several images. Compared with other geometric active contour models, the proposed method is more efficient and robust.

• International Journal of Control, Automation, and Systems
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• v.6 no.2
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• pp.194-203
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• 2008

Iterative learning control (ILC) is a simple and effective method for the control of systems that perform the same task repetitively. ILC algorithm uses the repetitiveness of the task to track the desired trajectory. In this paper, we propose a PID (proportional plus integral and derivative) type ILC update law for control discrete-time single input single-output (SISO) linear time-invariant (LTI) systems, performing repetitive tasks. In this approach, the input of controlled system in current cycle is modified by applying the PID strategy on the error achieved between the system output and the desired trajectory in a last previous iteration. The convergence of the presented scheme is analyzed and its convergence condition is obtained in terms of the PID coefficients. An optimal design method is proposed to determine the PID coefficients. It is also shown that under some given conditions, this optimal iterative learning controller can guarantee the monotonic convergence. An illustrative example is given to demonstrate the effectiveness of the proposed technique.

• International Journal of Control, Automation, and Systems
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• v.6 no.2
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• pp.171-179
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• 2008

This paper addresses the synthesis of an iterative learning controller for a class of linear systems with norm-bounded parameter uncertainties. We take into account an iterative learning algorithm with current cycle feedback in order to achieve both robust convergence and robust stability. The synthesis problem of the developed iterative learning control (ILC) system is reformulated as the ${\gamma}$-suboptimal $H_{\infty}$ control problem via the linear fractional transformation (LFT). A sufficient convergence condition of the ILC system is presented in terms of linear matrix inequalities (LMIs). Furthermore, the ILC system with fast convergence rate is constructed using a convex optimization technique with LMI constraints. The simulation results demonstrate the effectiveness of the proposed method.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.202-205
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• 2005

과학이 주는 가장 큰 이점인 인간의 편리함을 추구하는데 있어서 자동화라는 개념을 빼 놓을 수는 없을 것이다. 특히 인간생활의 기본이 되는 가정에서의 편리성은 항상 최우선되어져 왔다. 본 논문은 미래 사회 핵심 기술인 자동화의 가장 근본이 되는 Home Automation에 암호화 알고리즘을 통한 출입문 제어 시스템의 구현과 유비쿼터스의 개념을 도입하는 것에 그 목적이 있다. 현재까지 출입문 제어 시스템에 관한 수많은 논의와 연구가 이루어 졌지만 기존의 키 인증 방식은 한계가 존재하였다. 이에 인중서 개념 도입을 통한 암호화 알고리즘을 선보이고 기존의 키 인증시스템의 문제점을 해결하고 보안상의 문제도 해결하는 방법을 제안한다.

• Transactions of The Korea Fluid Power Systems Society
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• v.6 no.4
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• pp.9-15
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• 2009

Hydraulic excavators are the representative of field robot and have been used in various fields of construction. Since the excavator operates in the hazardous working environment, operators of excavator are exposed in harmful environment. Therefore, the hydraulic excavator automation and remote operation system has been investigated to protect from the hazardous working environment. In this paper, remote operation excavator system is developed using the mini hydraulic excavator and the tracking control system of each links of excavator is designed. To apply the tracking control system, the adaptive sliding mode control algorithm is proposed. It is found that the performance of the proposed control system is improved through experimental results of using the remote operation excavator system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.4
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• pp.56-61
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• 2014

In this paper, a control method using Sinusoidal Filter Controller of Silent Discharging Ozonizer is proposed and also the control methode performed robust control against variation of capacitance, command voltage and frequency. As the control system for this methode, Sinusoidal Filter Algorism can be simplified configuration of the power supply by using a low-pass filter. Through simulations and experiment results, the proposed control methode compensates for the high voltage waveform to the ozonizer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.523-528
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• 2015

A new algorithm for a coordinative control method is proposed with respect to voltage control and system stabilization of local substations. This is accomplished using control cooperation between a static synchronous compensator (STATCOM) and the existing voltage compensation equipment in the steady state and emergency state of a power system. A real-time system analysis was developed by combining a system analysis program with InTouch, which has primarily been used in factory automation for verification. PSS/E was used for the load flow calculation software, Python for language, Intouch as an HMI program, and MS SQL for the database. To test this system, the system in the vicinity of the Migeum and the Migeum substations was modeled and simulated.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.317-318
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• 2007

One of the important factors of the autonomous mobile robot is to build a map for surround environment and estimate its localization. This paper suggests a sensor fusion method of laser range finder and monocular vision sensor for the simultaneous localization and map building. The robot observes the comer points in the environment as features using the laser range finder, and extracts the SIFT algorithm with the monocular vision sensor. We verify the improved localization performance of the mobile robot from the experiment.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.2
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• pp.114-120
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• 2003

According to the use of distribution automation systems, the function to find or to search a fault phase is necessary for automatic switches in a distribution substation. In this paper, two algorithms are developed to fine the fault circuit and the fault phase for the automatic switches in substation with ungrounded power system. One is the fault circuit searching method using the zero sequence voltage at the bus and zero sequence current of circuit current and the other is to find the fault phase using the line voltage and zero sequence current. The developed algorithms are tested in the case study simulations. An ungrounded power system is modeled by EMTP as a case study system. The developed algorithms are tested in the case study simulations and each shows correct results.