• Journal of KSNVE
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• v.5 no.3
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• pp.385-394
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• 1995

Recently, since robot manipulator becomes faster and lighter, its link is no longer regarded as rigid body, and robot controller which only controls robot position cannot reduce vibration of the flexible link. Therefore vibration control is needed in robot manipulator control in addition to position control. In the case that tip mass changes when robot manipulator in working, it is clear that the efficiency of the vibration/position controller designed for the fixed system goes down. In this paper, the system with time varying parameters, adaptive control theory is adopted which estimates parameters changed by the variation of the tip mass and re-calculates the gain of the controller. Validify of the proposed adaptive controller and capability of the estimator are evaluated by computer simulations and experiments. Comparison results of the optimal controller for the fixed system and proposed adaptive controller and carried out.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3394-3408
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• 2014

Conventional mobile state (MS) and base station (BS) association based on average signal strength often results in imbalance of cell load which may require more powerful processor at BSs and degrades the perceived transmission rate of MSs. To deal with this problem, a Markov decision process (MDP) for load balancing in a multi-cell system with multi-carriers is formulated. To solve the problem, exploiting Sarsa algorithm of on-line learning type [12], ${\alpha}$-controllable load balancing algorithm is proposed. It is designed to control tradeoff between the cell load deviation of BSs and the perceived transmission rates of MSs. We also propose an ${\varepsilon}$-differential soft greedy policy for on-line learning which is proven to be asymptotically convergent to the optimal greedy policy under some condition. Simulation results verify that the ${\alpha}$-controllable load balancing algorithm controls the behavior of the algorithm depending on the choice of ${\alpha}$. It is shown to be very efficient in balancing cell loads of BSs with low ${\alpha}$.

• Journal of Distribution Science
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• v.11 no.6
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• pp.21-30
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• 2013

Purpose - This paper examines product design management, the current design focus of which has shifted to the need to produce innovation applications that can effectively respond to the market's consumption changes in a timely manner. Research design, data, methodology - This study discusses several methodologies that are widely used in experimental processes, such as fuzzy theory, multi-criteria decision-making theory, and managing decision making. The designers will better understand their customers by applying these methodologies. This study examines how the current trend in product innovation design observes customer needs, controls innovation, and stimulates design ability. Results - This paper takes innovative telephone design as an experimental case to investigate how to create a product using market-oriented and customized management concepts and creative design abilities. Conclusions - If accompanied by an innovative product value chain, a product can further the development of enterprise management, now the main element of every developed country's social and economic development.

• Journal of Multimedia Information System
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• v.2 no.3
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• pp.263-274
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• 2015

The subject of this work is the complex discrete systems simulation special features with the aid of dynamic graph models. The proposed simulation technique allows to determine the ways for tasks solutions in terms of discrete systems analysis and synthesis of various complication: one-dimensional and multidimensional, steady and unstable, with the pulse elements abnormal operating mode and others. Often complex control systems analysis and synthesis task solutions, via classical approach comes out to be insolvent, because of the computational problems. The application of graph models allows to perform clear and strict characterization and computer procedures automation. The optimal controls synthesis algorithm presented in this paper, transferring the discrete system from target initial state to target final state within the minimum time, allows to consider the zero initial conditions systems, with the initial potential energy, with the control actions limitations and complex pulse elements operating mode.

• 전기의세계
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• v.28 no.5
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• pp.44-48
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• 1979

For ordinary systems the receding horizon method has beer proved by the author as a very useful and easy tool to find stable feedback controls. In this paper an open-loop optimal control which minimizes the control energy with a suitable upper limit and terminal control and state constraints is derived and then transformed to the closed-loop control. The stable feedback control law is obtained from the closed-loop control. The stable feedback control law is obtained from the closed-loop control by the receding horizon concept. It is shown by the Lyapunov method that the control law derived from the receding, horizon concept is asymtotically stable under the complete controllability condition. The stable feedback control which is similar to but more general than the receding horizon control is presented in this paper To the author's knowledge the control laws in this paper are easiest to stabilize systems with delay in control.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.109-115
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• 2008

A burning principle in gasoline engine is the one of being burned, by which a mixer in air and gasoline enters a combustion chamber and causes a spark in the proper timing. This is formed, by which ECU controls the fuel-injection volume and the fuel-injection timing, and determines the performance of engine. The purpose of this study is to test the characteristics on knocking in gasoline engine with the knocking-sensor equipment and to research into the characteristics in knocking while directly controling the optimal igniting timing and the fuel-injection timing through engine ECU. Given controlling ECU by grasping the characteristics in knocking, which becomes the most problem in the engine tuning market, the tuning in a true sense will be formed in gasoline engine.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.653-658
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• 1994

This paper presents numerical analyses of the low speed yo-yo maneuver of an aircraft to determine controls of thrust, bank-angle and angle-of-attack in the subsonic region in terms of the optimal control theory. Minimum-time flight paths are numerically calculated to overtake an opponent aircraft flying in some steady-state level turnings under several assumptions: both of aircraft are point masses and maneuver in the 3-Dimensional space. Their weights are considered constant in the maneuver. As a result of the analyses, the effectiveness of the low speed yo-yo maneuver is shown.

• Journal of Industrial Technology
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• v.22 no.B
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• pp.251-260
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• 2002

In this thesis, a three degrees of freedom robot, which is able to provide sufficient precision for various robot researches, has been developed. The cable mechanism is used as a basic transmission of robot joints. Based on an optimal design strategy, link and joint parameters are determined and then overall geometry of the robot is designed. As an architecture of robot control, real time control system using real time linux and RtiC-Lab(Real Time Controls Laboratory) is developed. This system, written in C and based on Linux O/S, includes text editor, compiler, downloader, and real time plotter running in host computer for developing control purpose. Using these hardware and software, simple PD position control is implemented, the results shows the effectiveness of the system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.322-322
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• 2010

In this paper, we propose a novel type valveless micro-pump that uses extensional vibration mode of traveling wave as a volume transporting means for solving some problems about check valves, essential parts of usual pumps. The proposed pump consists of two piezoelectric ceramic rings and a metal body located in the middle of them respectively. Because the drift of bended surface that results from the traveling wave excitation controls the fluid flow, check valves are not needed in this pump model. In accordance with the variation of the pump body dimension, we analyzed the vibration displacement characteristics of pump model, determined the optimal design condition, fabricated the prototype pump from the analysis results and evaluated its efficiency.

• Journal of IKEEE
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• v.2 no.2 s.3
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• pp.255-262
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• 1998

The neural network can roughly be classified as the specialized control, indirect control and general schemes. Neural network is adopted for MPPT of solar array. And back propagation algorithm also is used to train neural network controller. We investigate the possibilities of $P_{max}$ control using the neural networks, and then we also examine about operating the solar cell at an optimal voltage comprise of temperature compensated voltage with boost converter. Proposed boost converter of MPPT system is studied by simulation and is implemented by using a microprocessor(80c196kc) which controls duty ratio of the boost converter.