• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.26-30
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• 2005

An LMI based method to construct a decentralized control law for large scale systems is discussed. It is extended to assure the stability not only of the overall system but also of each subsystem without interconnection. Then, it is simplified to have local feedback loops only for some selected subsystems.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.255-260
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• 1988

A robust adaptive control method for a stable nonminimum phase SISO system with unmodelled dynamics is proposed. The robust parameter estimation method of the system with bounded output noise and unmodelled dynamics is employed and a parallel structure is proposed to improve the robustness of adaptive control system. The local stability of the proposed system is shown. Computer simulations are done in order to compare the performance of the proposed structure with the basic structure on various circumstance.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.232-237
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• 1986

Theoretical studies are performed for a nonisothermal CFSTR in which consecutive reactions take place. The local dynamic stability of an unstable steady state is investigated with relation to variations in the controller gain when the temperature is subjected to a proportional control. The control has significant in fluences upon the stability of the high temperature steady state as well as that of the intermediate steady state.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2147-2151
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• 2011

In this paper, we propose the formation control algorithm for swarm robots. The proposed algorithm uses the artificial potential field(APF) to plan the global path of swarm robots and to control the formation movement. The navigation function generates a global APF for a leader robot to reach a given destination and an avoidance function generates a local APF for follow robots to avoid obstacles. Finally, some simulations show the validity of the proposed method.

• Journal of Biosystems Engineering
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• v.25 no.6
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• pp.457-462
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• 2000

Boom sprayers have been known by their excellency in field efficiency worker’s safety and pest control efficacy. The boom sprayer in Korea that was developed for paddy field is not suitable for upland field of which shape is irregular and inclination is steep, due to heavy chemical tank long boom width and manual on-off control of spraying. The goal of the study was to develope a boom control system that could control boom angles of left and right boom automatically and independently corresponding to local field slope. The prime mover was selected as a cultivating tractor. Main results of this study were as follows. 1. Ultrasonic sensor whose response time was 0.1s and response angle was within $\pm$20$^{\circ}$was selected to measure distance. Voltage output of the sensor(X, Volt) had a highly significant linear relationship with the vertical distance between the sensor and ground surface(Y, mm) as follows; Y=0.0036X-0.437 2. Left and right section of the boom could be folded up by a position control device(on-off control) which could control the left and right boom independently corresponding to local slope by equalizing distances between the sensor and boom at the center and left/right boom. Most reliable DB(dead band) was experimentally selected to be 75$\Omega$(6cm). 3. At traveling velocity of 0.3~0.5m/s RMS of error between desired and achieved height was less than 4.5cm The developed boom angle controller and boom linkage system were evaluated to be successful in achieving the height control accuracy target of $\pm$10cm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.417-420
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• 2006

UPnP presents home network middleware for local home electrical appliances basedon internet protocols that is available access and control electrical appliances just in local home network. Itis designed to bring easy-to-use, flexible, standards-based connectivity to ad-hoc or unmanaged networks in the home, a small business, public spaces, or attached to the Internet. In this paper, Internet Gateway expands UPnP IGD(Internet Gateway Device) DCP(Device Control protocol) and UPnP IGP Bridge for Internet Home Network Electrical Appliance Control. UPnP IGD DCP is configurable initiation and sharing of internet connections, advanced connection-management features, management of host configuration service, and supports transparent Internet access by non-UPnP-certified devices. UPnP Bridge search for local home network devices by sending control messages. Control Point of UPnP Bridge search for devices of interest on the network and can control or be controlled all of functions by IGD DCP with control commands. Outside client, approach to UPnP IGD DCP, send control messages UPnP Bridge, and invoke each UPnP device. As a result, Electrical Appliance of Home Network base on UPnP, can control and be controlled via the Internet like ones in the one Home Network without modification of existing UPnP.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.1
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• pp.145-155
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• 2010

This paper presents a new approach to obstacle avoidance for mobile robot in unknown or partially unknown environments. The method combines two navigation subsystems: low level and high level. The low level subsystem takes part in the control of linear, angular velocities using a multivariable PI controller, and the nonlinear position control. The high level subsystem uses ultrasonic and IR sensors to detect the unknown obstacle include static and dynamic obstacle. This approach provides both obstacle avoidance and target-following behaviors and uses only the local information for decision making for the next action. Also, we propose a new algorithm for the identification and solution of the local minima situation during the robot's traversal using the set of fuzzy rules. The system has been successfully demonstrated by simulations and experiments.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.119-125
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• 2012

This paper suggest the on-line coordination control between on-load tap changers and Switched Shunts for ensuring the voltage stability using local data obtained from one substation. Inappropriate control of on-load tap changers that are able to maintain voltage profile might cause unintended result that is harmful to system stability, especially voltage stability. This paper utilizes Z-index that could inform the whole system condition from only one substation data. Simulation is performed using the HYPERSIM that is a digital simulator and matlab simulink to confirm the proposed algorithm.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.2
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• pp.185-190
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• 2005

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. 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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.11
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• pp.1072-1078
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• 2008

An adaptive control algorithm for spacecraft rendezvous and docking in a Keplerian orbit is presented. The equations of relative motion of two spacecrafts expressed in a local-vertical-local-horizontal rectangular frame are converted to a general Hamiltonian form, then an adaptive control method developed for the uncertain Hamiltonian system is applied to the rendezvous and docking problem. A smooth projection algorithm is applied to keep the parameter estimates inside a singularity-free region, and a numerical example shows that the developed controller successfully deals with the unknown mass of the chaser spacecraft.