• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.330-333
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• 2006

Many practical problems of quality control in service management are derived from the use of ordinal variables. Ordered linguistic variables differ from measurement variables. This paper presents a new control chart of a production process based on ordinal variables.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.4
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• pp.315-319
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• 2006

Support vector machines in biped humanoid robot are presented in this paper. The trajectory of the ZMP in biped walking robot poses an important criterion for the balance of the walking robots but complex dynamics involved make robot control difficult. We are establishing empirical relationships based on the dynamic stability of motion using SVMs. SVMs and kernel method have become very popular method for learning from examples. We applied SVM to model the practical humanoid robot. Three kinds of kernels are employed also and each result has been compared. As a result, SVM based on kernel method have been found to work well. Especially SVM with RBF kernel function provides the best results. The simulation results show that the generated ZMP from the SVM can be improve the stability of the biped walking robot and it can be effectively used to model and control practical biped walking robot.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.54-64
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• 1997

This paper provides a practical control scheme called three-step input method in order to minimize both robot response time and the resulting residual vibration when the robot manipulator reaches its defined end point. This work is concerned with defining a simple practical method to utilize step inputs to achieve optimum response. The optimum response is achieved by using a self- adjusting input command function that is obtained during a real time processing . The practicality of this control scheme is demonstrated by using an analog computer to simulate a simulate a simple flexible robot and conventional servo controller. The experiments focus on point-to-point movement. Also, this method requires little computational effort through the intelligent use of conventional servo control technology and the robot's vibration characteristics.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.4
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• pp.9-21
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• 2003

This paper describes the practical implementation of a semiactive hydropneumatic suspension system to provide the high off-road performance of military tracked vehicles. Real gas behavior of a spring system, frictional forces of joints, and the dynamics of a continuously variable damper are considered. The control system is consisted of two control loops, an outer loop calculates a target spool position which can deliver the required damping force and an inner loop tracks the required spool position. Dynamic tests of the one axis model show that the semiactive suspension system considerably reduces the acceleration as well as velocity and displacement of the sprung mass than the passive one.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.518-520
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• 1999

The practical control problems for the time-delay system is considered. The delay-free characteristics of the Smith Predictor is available only when both the process and it's model are exactly matched. So it does not used widely in practical industrial processes. In this paper, using the 2nd-order plus deadtime model in place of the plant model of the Smith predictor, the proposed controller shows the improved performance in case of the very long time delay. And the range of integral constant of the PI controller is also proposed.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.91-93
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• 2009

In this paper, we present the Q-learning method for adaptive traffic signal control on the basis of In this paper, we present the Q-learning method for adaptive traffic signal control on the basis of multi-agent technology. The structure is composed of sixphase agents and one intersection agent. Wireless communication network provides the possibility of the cooperation of agents. As one kind of reinforcement learning, Q-learning is adopted as the algorithm of the control mechanism, which can acquire optical control strategies from delayed reward; furthermore, we adopt dynamic learning method instead of static method, which is more practical. Simulation result indicates that it is more effective than traditional signal system.

• Journal of Korean Society for Quality Management
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• v.36 no.1
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• pp.7-19
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• 2008

During the past two decades, a huge amount of research on adaptive control charts has been accomplished. Especially, variable sampling interval (VSI), variable sample size (VSS), and variable sample size and sampling interval (VSSI) charts have been focused by many researchers due to their simplicity and efficiency. On the other hand, the difference among notations, assumptions, methodologies may cause confusions in per forming further studies or practical implementations. This research analyses and compares diverse models so as to provide a unified view on statistical and economical characteristics. As a result, we perform comparative study on economical design models of VSI, VSS, and VSSI charts, respectively, We also present practical guidelines to utilize those adaptive control charts.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.25-28
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• 1995

A Practical application of self-tuning fuzzy controller to a multi-input multi-output complex system of a vehicle engine is investigated. The ovjective is to design a controller to improve the transient performance in torque and RPM mode changes. For the performance improvement in the multivariable comples system, the self-tuning function of internal parameters is essential and practical. The measured output variables using different control schemes are compared the advanteges of the self-tuning fuzzy logic controller are better output performances and the effectiveness in the controller design using many parameters.

• Smart Structures and Systems
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• v.7 no.5
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• pp.417-432
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• 2011

The present paper is devoted to vibration canceling and shape control of piezoelastic slender beams. Taking into account the presence of electric networks, an extended electromechanically coupled Bernoulli-Euler beam theory for passive piezoelectric composite structures is shortly introduced in the first part of our contribution. The second part of the paper deals with the concept of passive shape control of beams using shaped piezoelectric layers and tuned inductive networks. It is shown that an impedance matching and a shaping condition must be fulfilled in order to perfectly cancel vibrations due to an arbitrary harmonic load for a specific frequency. As a main result of the present paper, the correctness of the theory of passive shape control is demonstrated for a harmonically excited piezoelelastic cantilever by a finite element calculation based on one-dimensional Bernoulli-Euler beam elements, as well as by the commercial finite element code of ANSYS using three-dimensional solid elements. Finally, an outlook for the practical importance of the passive shape control concept is given: It is shown that harmonic vibrations of a beam with properly shaped layers according to the presented passive shape control theory, which are attached to an resistor-inductive circuit (RL-circuit), can be significantly reduced over a large frequency range compared to a beam with uniformly distributed piezoelectric layers.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.110.4-110
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• 2002

In practical control area, there are many examples with multiple objectives which may conflict or compete with each other like overhead crane control, automatic train operation, and refuse incinerator plant control, etc. These kinds of control problems are called multiobjective control problems, where it is difficult to provide the desired performance with control strategies based on single-objective optimization. Because the conventional control theories usually treat the control problem as the single objective optimization problem , the methods are not adequate to treat the multiobjective control problems. Particularly, in case of large scale systems or ill-defined systems, the multiple obj..