Kang-Woong Lee

Mobile robot navigation by circular path planning algorithm using camera and ultrasonic sensor

In this paper we propose a circular path planning algorithm using a monocular camera and ultrasonic sensors in order for a mobile robot to avoid obstacles. The proposed circular path algorithm determines the radius of a circular to avoid the detected obstacle using its position and size data. A monocular camera and ultrasonic sensors are used in order to compensate the shortage of usage of each sensor. Multiple sensor data are combined using the grid map method. Velocity of the mobile robot to move along the circular path to avoid an obstacle is controlled to guarantee stable motion. The control performance of the proposed algorithm is shown through the experiments using Pioneer2-DX mobile robot.

Mobile robot navigation using circular path planning algorithm

In this paper we propose a circular path planning algorithm for a mobile robot using only monocular vision system. The proposed method reduces the size of image data obtained by CCD camera to improve the image processing speed and noise immunity. A circular path for obstacle avoidance of the mobile robot is determined by the position and size of obstacles. Velocity of the mobile robot is controlled to guarantee stable movement. We show performance of the proposed method through experiments on Pioneer2-DX.

Gas turbine engine fault isolation based fuzzy inference logic with ECM trend plot report

A fuzzy inference logic system is proposed for gas turbine engine fault isolation. The gas path measurements used for fault isolation are exhaust gas temperature, low and high rotor speed, and fuel flow. The fuzzy inference logic uses rules developed from a model of performance influence coefficients to isolate engine faults while accounting for uncertainty in gas path measurements. Inputs to the fuzzy inference logic system are measurement deviations of gas path parameters which are transferred directly from the ECM (Engine Control Monitoring) program and outputs are engine module faults. The proposed fuzzy inference logic system is tested using simulated data developed from the ECM trend plot reports and the results show that the proposed fuzzy inference logic system isolates module faults with high accuracy rate in the environment of high level of uncertainty.

Policy Study on Efficient Aeronautical Frequency Band Allotment and Management in the Congested Air Traffic Environments

Aeronautical frequency band is to be internationally protected for aviation safety. Recently, with a rapid growth of an international air traffic, aeronautical frequency band is getting saturated, and thus may causes the interference in the congested frequency band. In this paper, an efficient aeronautical frequency allotment and management policies are proposed for resolving the existing problems in the aeronautical frequency band. The key activities include the review of the aeronautical frequency management and interference mitigation policies in a few important foreign countries such as United States and Japan. This policy study will be contributed for the future air safety in the aeronautical frequency management point of view.

Image-based Robust Control of Robot Manipulators with Image Jacobian and Dynamics Uncertainties

In this paper, we design an image-based robust controller to compensate uncertainties with image Jacobian and robot dynamics due to uncertain depth measurement and load variations. The proposed controller with eye-in-hand structure has separate terms to compensate each of uncertainties. The ultimate boundedness of the closed-loop system is proved by the Lyapunov approach. The performance of the proposed control system is demonstrated by simulation and experimental results a 5-link robot manipulator with two degree of freedom.

P-61: A Study on the Galvanic Reaction between Cu and Mo as Well as MoW for TFT-LCDs by Using a Zero-Resistance Ammeter

Recently, copper metallization has been widely developed in TFT-LCD industry, because of its lowest electrical resistivity compared to aluminum and its alloys. In addition, the copper metallization becomes a more significant issue in a high frequency driving technology for large sized TFT-LCD panel. Since copper has a low adhesion force against the glass substrate, copper is inevitably used with an aid of an adhesive metal layer such as Ti, Ta and Mo. When dissimilar metals like copper and molybdenum are exposed together in a wet etchant, a typical galvanic reaction occurs and this results in an undercutting of copper line or partial stains on the metal surface after drying. The suitable taper angle of Cu line is difficult to obtain especially coupled with pure molybdenum. Such failures often lead to a bad performance of thin film transistor and the display quality. There are many literatures related to the copper metallization for TFT. However, a systematic approach on the galvanic reaction occurred in copper multilayered system has not been made. In this work, we investigated a feasibility of molybdenum alloy film (MoW) for copper metallization on the basis of the thin film analysis and the advanced electrochemical techniques such as Zero Resistance Ammeter (ZRA) method.

79.2: Wet Patterning of Thin Films in Vertical Transfer Wet Station for TFT Manufacturing

Compared with tilt transfer wet station, vertical etching system has a many advantages that are 50% space savings, higher throughput and good etch uniformity over an entire glass for thin film transistor application. The aim of the present work is to analysis on a vertical etching system to improve the process factors. The computational fluid dynamics analysis is used to testify the change of the etch uniformity as a function of tilt angle of the glass substrate.

P-22: Electrical Stability of ZnO TFT during Gate-Bias Stress

We fabricated TFTs with ZnO thin film as an active layer. Electrical bias stress test of ZnO TFT was also carried out. The results of stress test of ZnO TFT differed from those of a-Si:H TFT. Therefore, the instability of ZnO TFT cannot be explained by conventional degradation mechanisms of a-Si:H TFT. The variance of some factors in the fabrication process showed a certain trend in the results of bias stress. A possible mechanism of abnormal behavior under the gate bias stress was discussed.

P‐67: Wet Etching of Gallium Indium Zinc Oxide (GIZO) Semiconductor for Thin Film Transistor Application

Recently, a significant progress has been made in the characterization of gallium indium zinc oxide (GIZO) as a new semiconductor layer instead of amorphous Si semiconductor used in thin film transistor. However, the wet behavior of GIZO thin film in the etching solutions which is conventionally used in TFT industry has not been reported yet. In this work, wet etch behavior of RF magnetron sputtered GIZO thin film in a new wet etchant was studied.

Fault Diagnosis in Gas Turbine Engine Using Fuzzy Inference Logic

A fuzzy inference logic system is proposed for gas turbine engine fault isolation. The gas path measurements used for fault isolation are exhaust gas temperature, low and high rotor speed, and fuel flow. The fuzzy inference logic uses rules developed from a model of performance influence coefficients to isolate engine faults while accounting for uncertainty in gas path measurements. Inputs to the fuzzy inference logic system are measurement deviations of gas path parameters which are transferred directly from the ECM(Engine Control Monitoring) program and outputs are engine module faults. The proposed fuzzy inference logic system is tested using simulated data developed from the ECM trend plot reports and the results show that the proposed fuzzy inference logic system isolates module faults with high accuracy rate in the environment of high level of uncertainty.