• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1873-1881
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• 2014

This paper deals with the design of multi-machine power system stabilizers (PSSs) and Static var compensator (SVC) using Modified shuffled frog leaping algorithm (MSFLA). The effectiveness of the proposed scheme for optimal setting of the PSSs and SVC controllers has been attended. The PSSs and SVC controllers designing is converted to an optimization problem in which the speed deviations between generators are involved. In order to compare the capability of PSS and SVC, they are designed independently once, and in a coordinated mode once again. The proposed method is applied on a multi-machine power system under different operating conditions and disturbances to confirm the effectiveness of it. The results of tuned PSS controller based on MSFLA (MSFLAPSS) and tuned SVC controller based on MSFLA (MSFLA SVC) are compared with the Strength pareto evolutionary algorithm (SPEA) and Particle swarm optimization (PSO) based optimized PSS and SVC through some performance to reveal its strong performance.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.315-318
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• 2003

A systematic output-tracking control design technique for robust control of Takagi-Sugeno (T-S) fuzzy systems with norm-bounded uncertainties is developed. The uncertain T-S fuzzy system is first represented as a set of uncertain local linear systems. The tracking problem is then converted into the stabilization problem for a set of uncertain local linear systems thereby leading to a more feasible controller design procedure. A sufficient condition for robust asymptotic output tracking is derived in terms of a set of linear matrix inequalities (LMIs). A stability condition on the traversing time-instances is also established. The output tracking control simulation for a flexible-joint robot-arm model is demonstrated, to convincingly show the effectiveness of the proposed system modeling and controller design method.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1241-1248
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• 2004

A controller of wheeled mobile robot(WMR) based on Lyapunov theory is designed and a Fuzzy-Neural Network algorithm is applied to this system to adjust controller gain. In conventional controller of WMR that adopts fixed controller gain, controller can not pursuit trajectory perfectly when initial condition of system is changed. Moreover, acquisition of optimal value of controller gain due to variation of initial condition is not easy because it can be get through lots of try and error process. To solve such problem, a Fuzzy-Neural Network algorithm is proposed. The Fuzzy logic adjusts gains to act up to position error and position error rate. And, the Neural Network algorithm optimizes gains according to initial position and initial direction. Computer simulation shows that the proposed Fuzzy-Neural Network controller is effective.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.207-209
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• 1995

The PID controller is widely used due to its fast response and robustness. But its performance is not so good compared with modem controllers such as adaptive, robust, fuzzy, neural controller. Therefore, it is natural to replace PID controller by modem controllers. But, the problem is that modem controller can not be easily applied to the real time process. Hence, this paper proposes such a structure that PID controller and Self-Learning Fuzzy Controller(SLFC) are in parallel with each other. The parameter of SLFC will be updated by gradient descent method using neuro - identifier. The usefulness of this hybrid controller will be proved by simulation results.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.87.3-87
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• 2001

The principle of matching is a new framework for control systems design that requires the matching between the control system and the environment (the source of exogenous inputs). The principle is especially useful for the design of the critical control systems where the responses of the control systems should be kept below the prescribed values. The design problem is reduced to find controller satisfying inequality constraints. However, conventional optimization techniques do not possess structural model selection ability and designers are required to select appropriate controller model. We propose to use a genetic algorithm to find an appropriate controller satisfying the matching conditions. The proposed genetic algorithm ...

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.9
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• pp.495-503
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• 2000

In this paper we propose a design procedure of loop-shaping two-degree-of-freedom H$\infty$ digital controller for sampled-data system. We extend the continuous time loop-shaping two-degree-of-freedom H$\infty$ control problem to sampled-data system. The configuration of generalized plant is modified for sampled-data system. And then using continuous lifting we obtain the digital controller. In the final stage of loop-shaping procedure the problem of absorbing weighting functions is discussed. We summarize this study to the design procedure and illustrate the application for an inverted pendulum on the cart.

• Smart Structures and Systems
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• v.13 no.3
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• pp.473-500
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• 2014

Tuned mass dampers (TMDs) have been installed in many high-rise buildings, to improve their resiliency under dynamic loads. However, high-rise buildings may experience natural frequency changes under ambient temperature fluctuations, extreme wind loads and relative humidity variations. This makes the design of a TMD challenging and may lead to a detuned scenario, which can reduce significantly the performance. To alleviate this problem, the current paper presents a proposed approach for the design of a robust and efficient TMD. The approach accounts for the uncertain natural frequency, the optimization objective and the input excitation. The study shows that robust design parameters can be different from the optimal parameters. Nevertheless, predetermined optimal parameters are useful to attain design robustness. A case study of a high-rise building is executed. The TMD designed with the proposed approach showed its robustness and effectiveness in reducing the responses of high-rise buildings under multidirectional wind. The case study represents an engineered design that is instructive. The results show that shear buildings may be controlled with less effort than cantilever buildings. Structural control performance in high-rise buildings may depend on the shape of the building, hence the flow patterns, as well as the wind direction angle. To further increase the performance of the robust TMD in one lateral direction, active control using LQG and fuzzy logic controllers was carried out. The performance of the controllers is remarkable in enhancing the response reduction. In addition, the fuzzy logic controller may be more robust than the LQG controller.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.936-938
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• 1999

In this Paper, the design of a feedback linearization controller using multilayer neural network is proposed. The Proposed feedback linearization control scheme is designed by finding Lie derivatives from an identified neural networks. Lie derivatives are expressed as a combination of weights and neuron outputs. The proposed method is applied to an antenna arm problem and the simulation results show performance comparisons between the ordinary feedback linearization and the Proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.99-102
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• 1995

In this paper, we consider the stabilization problem of nonstandard singularly perturbed systems by using state feedback. Different fro the existing sequenetial designn procedures, we propose a parallel design method to construct the stabilizing controller. The method involves solving two completely independent algebraic Riccati equations.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.4
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• pp.648-657
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• 1994

This paper presents a solution of the H$\infty$ control problem for a linear singularly perturbed system. A sufficient condition for a linear singularly perturbed system to achieve the prescribed disturbance attenuation level is obtained. Based upon this sufficient condition, an H$\infty$ controller design method which involves the solutions of two generalized algebraic Riccati equations(GRE) is developed.