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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
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Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 16, Issue 12 - Dec 1999
Volume 16, Issue 11 - Nov 1999
Volume 16, Issue 10 - Oct 1999
Volume 16, Issue 9 - Sep 1999
Volume 16, Issue 5 - May 1999
Volume 16, Issue 4 - Apr 1999
Volume 16, Issue 3 - Mar 1999
Volume 16, Issue 2 - Feb 1999
Volume 16, Issue 8 - Jan 1999
Volume 16, Issue 7 - Jan 1999
Volume 16, Issue 6 - Jan 1999
Volume 16, Issue 1 - Jan 1999
Selecting the target year
Development of 3-D Modeling for Abrasive Waterjet Drilling Process
Kwak, Hyo-Sung ; Kovacevic, Rodovan ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 7~14
Development of Vibration Motor Using Coreless Permanent Magnet DC Motor
Hwang, Sang-Moon ; Chung, Shi-Uk ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 15~23
With a remarkable expansion of communication industry, a pager or a cellular phone becomes a necessary communication device in modern society. However, a paging signal by a buzzer is often acted as an unpleasant noise in some places, thus necessitating a paging signal by a vibration motor. In this paper, a simpler type of a vibration motor, a coreless permanent magnet(PM) DC motor, is considered to substitute for the conventional vibration motors. Using an analytical method, electromagnetic field and operating torque were calculated for the given inner and outer PM type motors, and the results were confirmed by FEM analysis. As design parameters, number of PM poles, PM radial thickness, coil arc angle and number of winding stacks were chosen for sensitivity analysis. It shows that coil arc angle is the most important design parameter to increase the motor performance, without giving an adverse effect on motor weight, size and manufacturing cost. Based on the analysis of the outer PM type motor, an outer square PM type motor is proposed as the final design. Compared to the outer PM type, outer square type provides more flexibility to attach to the small size cellular phones. With the optimum design of square outer PM DC motor, it can successfully substitute the conventional types with less expensive manufacturing cost. better performance and smaller necessary space.
Development of Manufacturing Method of Vessel for Keeping Warm by Hydraulic Bulging
Chung, Joon-Ki ; Cho, Woong-Shick ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 24~31
Bulging is a forming method to shape of die cavity by using hydraulic pressure in tube or vessel. Bulging machine and die were developed in order to produce vessel for keeping warm. Bulging machine is a double type with two horizontal cylinders for bulging of two pieces at the same time. The developed die system has one bulging die and two drawing dies for necking at the both ends of tube. The diameter of tube expands by hydraulic pressure in tube. at the same time, thrust at the both ends of tube. pushes tube in the direction of expansion to obtain high expanding rate with no crack. In this study, the bulging properties were investigated to solve tube crack and necking in manufacturing vessel by the combination method of bulging and drawing. As a result, high expanding rate of tube radius without crack, precision necking and high productivity were obtained.
Ultrasonic C-scan System Development Using DSP
Nam, Young-Hyun ; Seong, Un-Hak ; Kim, Jeong-Tae ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 32~39
Digital signal processor (DSP) is used to obtain the peak value and the time difference of ultrasonic signals, to make digital filter, and to derive mathematical transformation from analog circuit. In this study, C-scan system and control program have been developed to high speed data acquisition. This system consists of signal processing parts (DSP, oscilloscope, pulser/receiver, digitizer), scanner, and control program. The developed system has been applied to a practical ultrasonic testing in overlay weld, and demonstrated high speed with precision
Characteristics of the Laser Displacement Sensor Using Optical Triangulation Method
Park, Jong-Sung ; Jeong, Kyu-Won ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 40~50
Recently, a laser displacement sensor is widely used for the manufacturing automation. The sensor is generally composed of a diode laser and a light receiving device. The diode laser emits a laser beam and the receiving device detects the light reflected from the measured object. The object position is obtained based upon triangulation method. As a light receiving device, a PSD is usually utilized since its structure is very simple and rugged and has a high accuracy. Although the theoretical relationship for this sensor had been developed, the characteristics of the sensor have not been much experimentally studied. In this paper, several experimental results will presented. The measurement accuracy is affected by the surface conditions such as the reflectance characteristics, the angle of the object's surface and the laser intensity. In addition, it is found that the PSD and the signal processing circuit have nonlinearities and showed that those nonlinearities can be reduced by controlling the emitting laser intensity
Structural Design of a Movable Bearing Shoe for Large Bridge Using Three Dimensional Finite Element Method
Cho, Jong-Rae ; Lee, Boo-Youn ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 51~57
Recently, long large bridges are built for mass transportation. Movable bearing shoes are important components of the bridges because they support movement of translation and rotation of bridge. In design stage of the long large bridges, detailed analyses using the finite element method are performed to guarantee safety and reliability. For that purpose, three-dimensional modeling is carried out by I-DEAS software and finite element analysis by ANSYS software. Results of the analyses are reviewed and important design factors for movable bearing shoes are discussed.
Research on the Intermittent Hard Turning (I) : Machinability and Characteristic of CBN Tools
Jeon, Jun-Yong ; Ko, Tae-Jo ; Kim, Hee-Sool ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 58~65
Hard turning offers many possible benefits over grinding such as lower equipment costs, shorter setup time, reduced process steps and better surface integrity. Despite the amount of research in this area, there exists no data in the intermittent hard turning. The objective of this paper is to investigate the effect of CBN tool materials and machinability to an intermittent hard turning. To this end, different CBN materials were tested to evaluate the tool wear and surface roughness in an intermittent hard turning. It is found that low-CBN-content tool is better than high-CBN-content tool. Then, we discussed a cutting force, vibration, and CBN tool wear mechanism from the hard turning
Relative Error Compensation of Robot Using Neural Network
Kim, Yeon-Hoon ; Jeong, Jae-Won ; Kim, Soo-Hyun ; Kwak, Yoon-Keun ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 66~72
Robot calibration is very important to improve the accuracy of robot manipulators. However, the calibration procedure is very time consuming and laborious work for users. In this paper, we propose a method of relative error compensation to make the calibration procedure easier. The method is completed by a Pi-Sigma network architecture which has sufficient capability to approximate the relative relationship between the accuracy compensations and robot configurations while maintaining an efficient network learning ability. By experiment of 4-DOF SCARA robot, KIRO-3, it is shown that both the error of joint angles and the positioning error of end effector are drop to 15
. These results are similar to those of other calibration methods, but the number of measurement is remarkably decreased by the suggested compensation method.
Development of an Expert System for Supporting Automatic Polishing Operation of Mold and Die
Lee, Tae-Moon ; Jeong, Hae-Do ; Hwang, Chan-Hae ; Cho, Kyu-Kab ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 73~84
An advanced expert system for supporting automatic polishing operation of mold and die has been developed. The goal of this system is to minimize the polishing time, the number of polishing and tools used. Also, this paper proposes the advanced concept of the polishing method to perform polishing operation of mold and die, and it has adapted to the orthogonal array method. as a statistical technique, to choose an optimal polishing condition. An expert system consists of the polishing machining database that includes the information of workpiece and polishing tools, and the input/output module.
A Development of the Algorithms for Automation of Slicing Machine with GUI Interface
Kim, Hyoung-Tae ; Yang, Hae-Jeong ; Song, Chang-Seop ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 85~93
In this study, PC-based slicing machine and driving software were constructed for the purpose of automation of semi-conductor cutting process. The biggest feature of software is variation of parameter and include data base, signal monitoring, error report, corresponding action or automatic motion planing. Parameters were drawn and algorithms were developed to make software by GUI interface. The cutting experiment was done for sampled wafer to see the effectiveness of the soft automation. From the experimented and implemented results, it is shown that parameters for automation of slicing process could be drawn, then its algorithms constructed. It could be considered what is the merit of this slicing machine by comparing the PC-based and the NC-based.
Characteristics of Surface Roughness in the High Speed Micro Turning of Aluminum Alloy
Seong, Chul-Hyun ; Kim, Hyeung-Chul ; Kim, Ki-Soo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 94~100
This study adopted the ultra precision machining system which was composed of an air bearing spindle, a granite bed, air pad and a linear feeding mechanism. It also applied the cutting experiment on the aluminum alloy. To evaluate the safety of high speed machining, we examined the surface roughness according to the changes of cutting speed and obtained the speed limit. This paper also studied the effect of cutting condition such as feed rates and depths of cut on the surface roughness within the speed limit. This provided practical information regarding ultra precision machining.
Study on Prediction of Drill Breakage using Spindle and Z-axis Motor Currents
Kim, Hwa-Young ; Ahn, Jung-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 101~108
A reliable and practical monitoring of drill breakage is a crucial technique in automatic machining system. In this study, a real-time monitoring system was developed to predict drill breakage using both spindle and z-axis motor current. Drill breakage is monitored by detecting the level of residual motor current which is obtained through the moving average filter algorithm. The residual exhibits a feature of sharp decrease just before drill breakage. Therefore, drill breakage can be predicted by detecting this characteristic of residual component. Z-axis motor current is better to predict the drill breakage than spindle motor current, because the former is faster in response than the latter when drill breakage is occurred. The evaluation experiments have shown that the developed monitoring system works very well.
A Real-Time Graphic Driving Simulator of the Construction Vehicle
Son, Kwon ; Choi, Kyung-Hyun ; You, Chang-Houn ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 109~118
A graphic software is one of the most important components of the vehicle simulator. To increase a visual reality of the simulator, the graphic software should require several technologies such as three-dimensional graphics, graphic modeling of the vehicle and the environment, drivers biomechanical models, and real-time data processing. This study presents a real time graphic driving simulator of a construction vehicle. The graphic simulator contains the three models of the construction vehicle, the human, and the environment, and employes a neural network approach to decrease an on-line dynamic computation. An excavator model is represented using an object-oriented paradigm and contains the detailed information about a real-size vehicle. The human model is introduced for objective visual evaluations of the developed excavator model. Since the environment model plays an important role in a real-time simulator, a block-based approach is implemented and a text format is utilized for easier construction of environment. The simulation results are illustrated in order to demonstrate the applicability of developed models and the neural network approach.
Camera Calibration with Two Calibration Planes and Oblique Coordinate Mapping
Ahn, Jeong-Ho ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 119~124
A method to find the line of sight ray in space which corresponds to a point in an image plane is presented. The line of sight ray is defined by two points which are the intersections between the two calibration planes and the sight ray. The intersection point is found by the oblique coordinate mapping between the image plane and the calibration plane in the space. The proposed oblique coordinate mapping method has advantages over the transformation matrix method in the required memory space and computation time.
A Study on the Comparison of 2-D Circular Object Tracking Algorithm Using Vision System
Han, Kyu-Bum ; Kim, Jung-Hoon ; Baek, Yoon-Su ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 125~131
In this paper, the algorithms which can track the two dimensional moving circular object using simple vision system are described. In order to track the moving object, the process of finding the object feature points - such as centroid of the object, corner points, area - is indispensable. With the assumption of two-dimensional circular moving object, the centroid of the circular object is computed from three points on the object circumference. Different kinds of algorithms for computing three edge points - simple x directional detection method, stick method. T-shape method are suggested. Through the computer simulation and experiments, three algorithms are compared from the viewpoint of detection accuracy and computational time efficiency.
An Intermediate Model for Development of a Simulation Program of a Production System with Robots
Kuk, Kum-Hoan ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 132~143
In this study, an intermediate model is presented as a new method for development of a parametric simulation program. This model enables us to analyze effectively the static and dynamic structure of a real production system. The static structure of the real system can be modelled in an entity-relationship diagram and the dynamic structure of the real system in a Petri net. The intermediate model consists of an entity-relationship diagram and a Petri net. Using this intermediate model man can not only reduce the time and cost for simulation program development, but also increase the modelling reliability of the developed simulation program. To show the usefulness of this intermediate model. the intermediate models for two production subsystems, manufacturing sub-system and transport subsystem, are set up.
Control for Multi-variable in Crane System using Fuzzy Learning Method
Lim, Yoon-Kyu ; Chung, Byeong-Mook ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 144~150
n active control for the swing of crane systems is very important for increasing the productivity. This article introduces the control for the position and the swing of a crane using the fuzzy learning method. Because the crane is a multi-variable system, learning is done to control both position and swing of the crane. Also the fuzzy control rules are separately acquired with the loading and unloading situation of the crane for more accurate control. The result of simulations shows that the crane is just controlled for a very large swing angle of 1 radian within nearly one cycle.
Dynamic Characteristics Analysis and Chatter Prediction in High Speed CNC Lathe
Lee, Woo-Seok ; Lee, Sin-Young ; Lee, Jang-Moo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 151~157
Vibrations in machine tools make many problems in precision, production efficiency, and machine performance. The relative vibration between a workpiece and a tool is very complicated due to many sources. In this study, the dynamic characteristics of a newly developed CNC lathe were analyzed and its chatter characteristics were predicted by a chatter analysis method using finite element analysis and 3 dimensional cutting dynamics. The simulated results showed very complex characteristics of chatter vibration and the borderline of limiting depth of cut was used as the stability limit. To check the validity of this method, cutting tests were done in the CNC lathe using a boring bar as a tool because boring process is very weak due to long overhang . The experimental results showed that the simplified borderline was to be considered as limiting depth of cut at which the chatter vibration starts and the stability limits depended on various cutting parameters such as cutting speed, feed and nose radius of tool.
Finite Element Analysis of Heat and Moisture Transfer in Porous Materials
Lee, Ho-Rim ; Geum, Yeong-Tak ; Song, Chang-Seop ; O, Geun-Ho ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 158~167
Heat and moisture transfer associated with porous materials are investigated. The heat and moisture transfer in porous materials caused by the interaction of moisture gradient, temperature gradient, conduction, and evaporation are considered. The variations of temperature and moisture not only change the volume but also induce the hygro-thermal stress. The finite element formulation for solving the temperature and moisture transfer as well as the associated hygro-thermal stresses is developed. In order to verify the finite element formulation, the heat and moisture moving boundary problem in a half space and the hygro-thermo-mechanical problem in an infinite plate with a circular hole are analyzed. Temperature profile, moisture profile, and hygro-thermal stresses are compared with those of analytic solution and other investigator. Good agreements are examined
A Study on the Prediction of Fatigue Damage in 2024-T3 Aluminium Alloy Using Neural Networks
Cho, Seok-Swoo ; Jang, Deuk-Yul ; Joo, Won-Sik ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 168~177
Fatigue damage is the phenomena which is accumulated gradually with loading cycle in material. It is represented by fatigue crack growth rate da/dN and fatigue life ratio
. Fracture mechanical parameters estimating large crack growth behavior can calculate quantitative amount of fatigue crack growth resistance in engineering material. But fatigue damage has influence on various load, material and environment. Therefore, In this study, we propose that artificial intelligent fatigue damage model can predicts fatigue crack growth rate da/dN and fatigue life ratio
simultaneously using fracture mechanical and nondestructive parameters.
Identification of ARMAX Model and Linear Estimation Algorithm for Structural Dynamic Characteristics Analysis
Choe, Eui-Jung ; Lee, Sang-Jo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 178~187
In order to identify a transfer function model with noise, penalty function method has been widely used. In this method, estimation process for possible model parameters from low to higher order proceeds the model identification process. In this study, based on linear estimation method, a new approach unifying the estimation and the identification of ARMAX model is proposed. For the parameter estimation of a transfer function model with noise, linear estimation method by noise separation is suggested instead of nonlinear estimation method. The feasibility of the proposed model identification and estimation method is verified through simulations, namely by applying the method to time series model. In the case of time series model with noise, the proposed method successfully identifies the transfer function model with noise without going through model parameter identification process in advance. A new algorithm effectively achieving model identification and parameter estimation in unified frame has been proposed. This approach is different from the conventional method used for identification of ARMAX model which needs separate parameter estimation and model identification processes. The consistency and the accuracy of the proposed method has been verified through simulations.
A Study on the Mechanical States of Machined Surface by Considering Cutting Edge
Kim, Joo-Hyun ; Woo, Hee-Sun ; Chang, Yoon-Sang ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 188~195
Cutting edge plays an important role in generating machined surface. In order to consider the geometric effects of the cutting edge on mechanical states, the concept of ploughing force and stagnation point was introduced which explains the generating mechanism of machined surface during cutting. The effects of edge radius and nose radius of cutting tool on the distribution of residual stresses of the machined surface having several hardness were studied. Good machined surface having high compressive residual surface stresses can be achieved if cutting tools having large edge radius and small nose radius are used for cutting work materials having high hardness with high depth of cut. The magnitude of edge radius and the hardness of work material also affected the shape of the chip in orthogonal cutting.
Flame Diagnosis using Image Processing Technique
Lee, Tae-Young ; Kim, Song-Hwan ; Lee, Sang-Ryong ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 196~202
Recent trend changes a criterion for evaluation of burner that environmental problem is raised as global issue. For efficient driving problem, the higher thermal efficiency and the lower oxygen in exhaust gas, burner is evaluated the better. For environmental problem, burner must satisfy
limit and CO limit. Consequently, 'good burner' means on whose thermal efficiency is high under the constraint of
and CO consistency. To make existing burner satisfy recent criterion, it is highly recommended to develop feedback control scheme whose output is the consistency of
and CO. This paper describes development of real time flame diagnosis technique that evaluate and diagnose combustion state such as consistency of components in exhaust gas, stability of flame in quantitative sense. This study focuses on wave length of luminescence from chemical reaction measurement of the luminescence via optical measuring apparatus and derive correlation with consistency of components in exhaust gas by image processing technique.
Prediction of the Milled Surface Shapes Considering Tool Deflection Effects in Profile Milling Process
Seo, Tae-Il ; Cho, Myeong-Woo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 203~209
In this paper, we present the methods to predict the milled surface shapes in profile milling process. In the cutting process, tools are deflected due to the cutting forces varying with the imposed depth of cut and feedrate. Thus, the final shapes of the milled surface, generated by the nominal tool trajectory, are different from the required profile. In order to predict the milled surface shapes, we present two methods based on: (1) the deflected tool profile and (2) the trace of contact point between the tool and the workpiece. In the first method, we make an assumption that the milled surface corresponds to the deflected tool profile. In another method, we make we make an assumption that the milled surface is generated by the trace of the contact point between the cutting edge of the tool and workpiece. We present the surface generation process by calculating the trajectory of the contact points on the workpiece. Several simulations and experiments are performed to verify the proposed milled surface prediction methods.
Development of Sheet Deposition Type Rapid Prototyping System Minimizing Post Processing
Cho, In-Haeng ; Lee, Kun-Woo ; Song, Yong-Ak ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 7, 1999, Pages 210~218
Sheet deposition type rapid prototyping system have many advantages : high build speed, low operating cost, large part size, no phase change, no need for support generation, and forth. However, those sheet deposition type rapid prototyping system require an additional post processing to remove excessive material attached to the part. This post processing is time consuming and labor intensive. Moreover, it is difficult for those system to fabricate parts with hollow cores and internal cavities. A new sheet deposition type rapid prototyping system that minimizes the post processing is proposed. The proposed system automatically removes excessive material in a peeling-off process between two cutting processes. In this way, the proposed system can reduce the post-processing time and cost as well as the limitation of the feasible geometric shapes in the conventional sheet deposition system.