on-Youl So

Globally Stable Adaptive Fuzzy Control for Strict-feedback Nonlinear Systems

A new adaptive fuzzy controller for uncertain strict-feedback nonlinear systems is proposed. All the previous approximator-based adaptive control algorithms for the strict-feedback nonlinear systems are based on backstepping scheme and guarantee semi-global closed-loop system stability. This paper proposes a new globally stabilizing adaptive fuzzy controller for strict-feedback nonlinear system without backstepping. To this end, an online self-structuring adaptive fuzzy system is employed. The proposed adaptive fuzzy controller is considerably simpler than the previous ones based on backstepping. Only one FLS is employed to approximate a lumped uncertain nonlinearity, which highlights the simplicity of our proposed control scheme.

A Study on Design of Control Device on Small Wind Generator Using 2-Level Boost Converter

The small wind generator with existing mechanical control system has a frequent failure and malfunction, and its maintenance is difficult. In this paper, an electric control method using a boost converter for small wind generator was suggested. The suggested 2-level boost converter control device was manufactured and its experimental operation were conducted on a wind generator with 200 [W] capacity. As a result of experimental device, the control by a boost converter was executed at the point that the output voltage of a wind generator became 36 [V] so it could be identified that the output voltage of a wind generator diminished and then it became 0 [V] after 5 [sec]. Besides, in case of applying the method suggested in this paper to a small wind power generation facility for street lights, it is expected to reduce its maintenance by preventing a frequent failure of a generator and to improve its utilization rate.

Adaptive Neural Control for Pure-feedback Nonlinear Systems

An adaptive neural control problem of SISO fully nonaffine pure-feedback nonlinear system is considered in this paper. The main contribution of the proposed method is that it is shown that the control problem of the pure-feedback system can be viewed as that of the system in the standard normal form. As a result, proposed neural control algorithm is much simpler compared to the recently proposed backstepping-based neural controllers. Depending heavily on the universal approximation property of the neural network (NN), only one NN is employed to approximate lumped uncertain nonlinearity in the controlled system. It is shown that the Lyapunov stabilities of the NN weights and filtered tracking error are guaranteed in the semi-global sense.

Hybrid and Etch-Less Electrooptic Waveguide Modulator Based on Photo-Bleaching and Strain Induced Optical Waveguide Technique in Polymer

A hybrid and etchless electrooptic (EO) polymer waveguide modulator based on both a photo-bleaching-induced optical waveguide (PBOW) and a strain-induced optical waveguide (SIOW) is described. The SIOW is defined by a metal strip line stressor deposited on top of the upper cladding that introduces the refractive index change within the core region. The PBOW technique is used to form an optical waveguide which is based on a photo-bleaching process, known as a photo-oxidation that is an irreversible decomposition of EO material, resulting in a permanent decrease in index of refraction. It is shown that this proposed fabrication idea combining two etchless techniques can be applicable to a wide range of polymer photonic integrated circuits. Preliminary results obtained from fabricated devices reveal that their half-wave voltage are ranging from 8 V to 10 V, their extinction ratio exhibits more than 15 dB, and the fiber-to-waveguide-to-lens loss is estimated to be ~9.5 dB for TM polarization at 1.55/m wavelength in the active interaction of ~1.5 cm long.

Development of LED Auxiliary Power System for Ship using DSSC

The color and the installation position of the LED lamp for night voyage of the ship are changed by the purpose of it. The power dissipation occurs because a navigation light is on and off or continuously on. In addition, in case that the light is produced by operating generator in the ship, its very inefficient except that its on a voyage. Therefore in this dissertation, we construct auxiliary power system for the LED lamp of the ship, producing and developing a module, a panel, and a charging system using Dye-sensitize Solar Cell.

The Analysis of DC Plasmas Characteristics on SFSF 6 and N 2 Mixture Gases

SF6 gas has been used for power transformers or gas insulated switchgears, because it has the superior insulation property and the stable structure chemically. It has been, however, one of global warming gases and required to reduce the its amount. Some papers have reported that its amount could be reduced by mixing with other gases, such as N2, CF4, CO2 and C4F8 and their mixture gases would cause the synergy effect. In this paper, we investigated the characteristics of DC plasmas on SF6 mixture gases with N2 at atmospheric pressure. N2 gas is one of cheap gases and has been reported to show the synergy effect with mixing SF6 gas, even though N2 plasmas have electron-positive characteristics. 38 kinds of SF6/N2 plasma particles, which consisted of an electron, two positive ions, five negative ions, 30 excitation and vibration particles, were considered in a one dimensional fluid simulation model with capacitively coupled plasma chamber. The results showed that the joule heating of SF6/N2 plasmas was mainly caused by positive ions, on the other hand electrons acted on holding the SF6/N2 plasmas stably. The joule heating was strongly generated near the electrodes, which caused the increase of neutral gas temperature within the chamber. The more N2 mixed-ratio increased, the less joule heating was. And the power consumptions by electron and positive ions increased with the increase of N2 mixed-ratio.