• 전자공학회논문지SC
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• 제39권5호
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• pp.8-17
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• 2002

본 논문에서는, 섭동과 제어기 이득 섭동을 갖는 이산 대규모 시간지연 시스템의 강인 비약성 제어기 설계에 관하여 논한다. 리아프보프 해석법을 의거하여 선형행렬 부등식으로 표현되는 주어진 시스템의 강인 안정화를 꾀하는 상태 궤환 제어기의 존재를 보장하는 조건 식을 구한다. 이 조건 식의 해로부터 각 부 시스템에서의 제어기의 이득 및 제어기의 비약성 지수도 얻을 수 있다. 제시된 선형행렬 부등식은 잘 알려진 최적화 기법으로 쉽게 풀 수 있으며, 예제를 통하여 제어기 설계 방법을 보인다.

• International Journal of Precision Engineering and Manufacturing
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• 제1권2호
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• pp.24-34
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• 2000

In this paper we propose a controller design method, called Quasi-LQG/$H_{\infty}$/LTR for nonlinear servo systems with hard nonlinearities such as Coulomb friction, dead-zone. Introducing the RIDF method to model Coulomb friction and dead-zone, the statistically linearized system is built. Then, we consider $H_{\infty}$ performance constraint for the optimization of statistically linearized systems, by replacing a covariance Lyapunov equation into a modified Riccati equation of which solution leads to an upper bound of the LQG performance. As a result, the nonlinear correction term is included in coupled Riccati equation, which is generally very difficult to thave a numerical solution. To solve this problem, we use the modified loop shaping technique and show some analytic proofs on LTR condition. Finally, the Quasi-LQG/$H_{\infty}$/LTR controller for a nonlinear system is synthesized by inverse random input describing function techniques (ITIDF). It is shown that the proposed design method has a better performance robustness to the hard nonlinearity than LQG/$H_{\infty}$/LTR method via simulations and experiments for the timing-belt driving servo system that contains the Coulomb friction and dead-zone.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.478-489
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• 2013

The controllability and stability of power systems can be increased by Flexible AC Transmission Devices (FACTs). One of the FACTs devices is Interline Power-Flow Controller (IPFC) by which the voltage stability, dynamic stability and transient stability of power systems can be improved. In the present paper, the convenient operation and control of IPFC for transient stability improvement are considered. Considering that the system's Lyapunov energy function is a relevant tool to study the stability affair. IPFC energy function optimization has been used in order to access the maximum of transient stability margin. In order to control IPFC, a Brain Emotional Learning Based Intelligent Controller (BELBIC) and PI controller have been used. The utilization of the new controller is based on the emotion-processing mechanism in the brain and is essentially an action selection, which is based on sensory inputs and emotional cues. This intelligent control is based on the limbic system of the mammalian brain. Simulation confirms the ability of BELBIC controller compared with conventional PI controller. The designing results have been studied by the simulation of a single-machine system with infinite bus (SMIB) and another standard 9-buses system (Anderson and Fouad, 1977).

• Steel and Composite Structures
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• 제51권5호
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• pp.473-485
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• 2024

This paper proposes a composite form of fuzzy adaptive control plan based on a robust observer. The fuzzy 2D control gains are regulated by the parameters in the LMIs. Then, control and learning performance indices with weight matrices are constructed as the cost functions, which allows the regulation of the trade-off between the two performance by setting appropriate weight matrices. The design of 2D control gains is equivalent to the LMIs-constrained multi-objective optimization problem under dual performance indices. By using this proposed smart tracking design via fuzzy nonlinear criterion, the data link can be further extended. To evaluate the performance of the controller, the proposed controller was compared with other control technologies. This ensures the execution of the control program used to track position and trajectory in the presence of great model uncertainty and external disturbances. The performance of monitoring and control is verified by quantitative analysis. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings, sustainable human settlement planning and manage. Therefore, the goal is believed to achieved in the near future by the ongoing development of AI and control theory.

• 자동차안전학회지
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• 제5권2호
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• pp.24-31
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• 2013

This paper describes a coordinated control algorithm for rear-side collision avoidance. In order to assist driver actively and increase driver's safety, the proposed coordinated control algorithm is designed to combine lateral control using a steering torque overlay by Motor Driven Power Steering (MDPS) and differential braking by Vehicle Stability Control (VSC). The main objective of a combined control strategy is twofold. The one is to prevent the collision between the subject vehicle and approaching vehicle in the adjacent lanes. The other is to limit actuator's control inputs and vehicle dynamics to safe values for the assurance of the driver's comfort. In order to achieve these goals, the Lyapunov theory and LMI optimization methods has been employed. The proposed coordinated control algorithm for rear-side collision avoidance has been evaluated via simulation using CarSim and MATLAB/Simulink.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1686-1693
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• 2014

In this paper, oil-paper samples composed of transformer windings were used to investigate the insulation degradation process subjected to partial discharge (PD), with artificial defects inside to simulate the PD induced insulation degradation. To determine appropriate test voltages, the breakdown time obtained through a group of accelerated electrical degradation tests under high voltages was firstly fitted by two-parameter Weibull model to acquire the average breakdown time, which was then applied to establish the inverse power law life model to choose advisable test voltages. During the electrical degradation process, PD signals were synchronously detected by an ultra-high frequency (UHF) sensor from inception to breakdown. For PD analysis, the whole degradation process was divided into ten stages, and chaos theory was introduced to analyze the variation of three chaotic parameters with the development of electrical degradation, namely the largest Lyapunov exponent, correlation dimension and Komogorov entropy of PD amplitude time series. It is shown that deterministic chaos of PD is confirmed during the oil-paper degradation process, and the obtained results provide a new effective tool for the diagnosis of degradation of oil-paper insulation subjected to PD.

• 한국항공우주학회지
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• 제41권3호
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• pp.200-209
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• 2013

본 논문에서 B-dot 제어기 종류, Lyapunov 안정성 관점에서 B-dot 제어기 안정성 검토 결과 요약이 제시되었다. 6시 태양동기 궤도의 대형위성이 초기 자세획득 할 때 또는 이상상태 발생 후 태양획득을 위해 B-dot 제어기가 사용될 경우, B-dot 제어기의 활용성에 대한 검토 결과 제어기 활용성이 매우 높다는 결론을 얻을 수 있었다. 또한 B-dot 제어기 작동원리의 이해를 위해 천이상태 제어토크와 정상상태 제어토크 개념을 도입해서 새로운 물리적 해석 결과를 도출 제시하였으며, 자기 토커가 고장 났을 때 자세 안정화에 미치는 영향을 이론적으로 분석 후 토커고장에 대한 설계 최적화 방안을 제시하였다. 또한 6시 태양동기 궤도의 대형위성에서 B-dot 제어기의 유용성 및 자기토커 고장 영향 분석결과 확인을 위해 비선형 시뮬레이션 결과 만족스런 태양지향능력 및 예측된 고장 영향 분석결과 등이 확인되었다.