• 제어로봇시스템학회논문지
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• 제16권3호
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• pp.207-214
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• 2010

This paper proposes about decentralized control approach based Leader-Follower formation control using LOS (Line of Sight) algorithm and unknown input observer. The position of robots which is a basic information in multi-robot or single robot motion control is determined by localization algorithm fusing UPS (Ultrasonic Position System) and kinematics model. For formation control, a decentralized control approach individually installing a local controller in leader and follower robot is adopted. Leader robot is controlled to track a specified trajectory by LOS algorithm, and the other robots follow the leader by local controller based on tracking platoon level function, self-sensing data and estimated information from unknown input observer. The performance of proposed method is proven through the formation experiment of two vehicle models.

• Journal of Power Electronics
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• 제16권6호
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• pp.2315-2326
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• 2016

This paper discusses the elimination of DC voltage deviation and the enhancement of load current sharing accuracy in multi-terminal high voltage direct current (MT-HVDC) systems. In order to minimize the power line losses in different parallel network topologies and to insure the stable operation of systems, a decentralized control method based on a modified droop control is presented in this paper. Averaging the DC output voltage and averaging the output current of two neighboring converters are employed to reduce the congestion of the communication network in a control system, and the decentralized control method is implemented. By minimizing the power loss of the cable, the optimal load current sharing proportion is derived in order to achieve rational current sharing among different converters. The validity of the proposed method using a low bandwidth communication (LBC) network for different topologies is verified. The influence of the parameters of the power cable on the control system stability is analyzed in detail. Finally, transient response simulations and experiments are performed to demonstrate the feasibility of the proposed control strategy for a MT-HVDC system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.494-497
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• 2005

Direct velocity feedback (DVFB) control with a collocated distributed actuator and point sensor pair is known that it offers a good stability with high performance when the control strategy is applied at the suppression of structural vibration. Also decentralized control method introduced to offer to reduce implementaion effort and malfunction due to failure in sensors and actuators of control system has become an important position in DVFB. In this paper, the decentralized control is compared with centralized control in terms of vibrational velocity reduction in a clamped-clamped beam.

• 한국항공우주학회지
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• 제43권10호
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• pp.859-867
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• 2015

본 논문은 행위 기반 분산 기법(behavior-based decentralized method)을 활용하여 복수 무인기의 군집 비행을 위한 강인 제어기를 제안한다. 행위 기반 분산 기법을 활용한 복수 무인기의 군집 비행은 주변 무인기들의 정보만을 활용하여 편대를 이루게 되므로 많은 장점을 갖는다. 본 논문에서는 무인기 시스템에 크기가 제한된 시변 외란(time varying bounded disturbance)이 존재하는 상황에서, 주변 무인기들의 위치와 속도를 모두 활용하는 경우와 위치만을 활용하는 경우로 나뉘어 제어기를 설계하며, 위치만을 활용하는 경우 passivity 기법을 적용하여 제어기를 설계한다. 제안된 제어기는 시간에 의존하는 제한된 외란이 존재하는 상황에서 전체 폐루프 시스템의 uniformly ultimate boundedness 특성을 보장한다. 수치 시뮬레이션을 통해 제안된 제어기법의 타당성을 검증한다.

• Journal of information and communication convergence engineering
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• 제6권2호
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• pp.198-203
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• 2008

An Intelligent optimal control system design algorithm in active suspension equipment adopting linear matrix inequalities control system design theory with representing by descriptor system form is presented. The validity of the linear matrix inequalities intelligent decentralized control system design with representing by descriptor system form in active suspension system through the numerical examples is also investigated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1909-1914
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• 2004

Passive velocity field control (PVFC) was previously developed for fully mechanical systems, in which the motion task was specified behaviorally in terms of a velocity field, and the closed-loop was passive with respect to a supply rate given by the environment input. However the PVFC was only applied to a single manipulator, the proposed control law was derived geometrically, and the geometric and robustness properties of the closed-loop system were also analyzed. In this paper, we propose a method to apply a decentralized control algorithm to cooperative 3-wheeled mobile robots whose subsystem is under nonholonomic constraints and which convey a common rigid object in a horizontal plain. Moreover it is shown that multiple robot systems ensure stability and the velocities of augmented systems convergence to a scaled multiple of each desired velocity field for cooperative mobile robot systems.

• 한국지능시스템학회논문지
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• 제12권1호
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• pp.80-84
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• 2002

본 논문은 2자유도 실험용 헬리콥터 시스템의 제어를 위한 분산 제어기 설계 기법을 제안한다. 분산제어기법은 특히 대규모 제어 시스템에 적합하다고 알려져 있다. 본 논문에서는 Lyapunov 안정도 설계 방법을 이용하여 상호 연결된 TS 퍼지 시스템의 안정도 조건을 유도하고 선형 행렬 부등식을 이용하여 제어기 설계 조건을 공식화한다. 제안된 방법의 유용성을 검증하기 위해, 컴퓨터 시뮬레이션뿐 만 아니라 실험을 통해 그 결과를 도출한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.50.5-50
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• 2002

In this paper, we propose a method using neural network (NN) to improve the motion control of a decentralized control system for cooperative transportation. In our former work, a decentralized control system for transporting a single object by multiple nonholonomic mobile robots has been developed. One of these mobile robots acts as a leader, who is assumed to be able to plan and to manipulate the omnidirectional motion of the object. Other robots, referred to as followers, cooperatively transport the object by keeping a constant position relative to the object. in this work, it is assumed that the leader can not only plan but also broadcast the local velocity of the object. Then...

• 제어로봇시스템학회논문지
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• 제2권2호
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• pp.88-95
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• 1996

It is inevitable for local systems to have deviations which represent interactions and modeling errors originated from the decomposition process of a large scale system. This paper presents a decentralized control scheme for interconnected systems using local linear models and a neuro-coordinator. In the proposed method, the local system is composed of a linear model and unknown deviations caused by linearizing the subsystems around operating points or by estimating parameters of the subsystems. Because the local system has unmeasurable deviations we define a local reference model which consists of a local linear model and a neural network to estimate the deviations indirectly. The reference model is reformed into a linear model which has no deviations through a transformation of input variables and we obtain an optimum feedback control law which minimizes a local performance index. Finally, we derive a decentralized feedback control law which consists of local linear states and neural network outputs. In the decentralized control, the neuro-coordinator generates a corrective control signal to cancel the effect of deviations through backpropagation learning with the errors obtained from the differences of the local system outputs and reference model outputs. Also, the stability of local system is proved by the degree of learning of the neural network under an assumption on a neural network learning index. It is shown by computer simulations that the proposed control scheme can be applied successfully to the control of a biased two-link planar robot manipulator.

• Smart Structures and Systems
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• 제4권6호
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• pp.779-794
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• 2008

Observer-based fault detection and isolation (FDI) filter design method is a model-based method. By carefully choosing the observer gain, the residual outputs can be projected onto different independent subspaces. Each subspace corresponds to the monitored structural element so that the projected residual will be nonzero when the associated structural element is damaged and zero when there is no damage. The key point of detection filter design is how to find an appropriate observer gain. This problem can be interpreted in a geometric framework and is found to be equivalent to the problem of finding a decentralized static output feedback gain. But, it is still a challenging task to find the decentralized controller by either analytical or numerical methods because its solution set is, generally, non-convex. In this paper, the concept of detection filter and iterative LMI technique for decentralized controller design are combined to develop an algorithm to compute the observer gain. It can be used to monitor structural element state: healthy or damaged. The simulation results show that the developed method can successfully identify structural damages.