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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 26, Issue 12 - Dec 2009
Volume 26, Issue 11 - Nov 2009
Volume 26, Issue 10 - Oct 2009
Volume 26, Issue 9 - Sep 2009
Volume 26, Issue 8 - Aug 2009
Volume 26, Issue 7 - Jul 2009
Volume 26, Issue 6 - Jun 2009
Volume 26, Issue 5 - May 2009
Volume 26, Issue 4 - Apr 2009
Volume 26, Issue 3 - Mar 2009
Volume 26, Issue 2 - Feb 2009
Volume 26, Issue 1 - Jan 2009
Selecting the target year
Introduction to UUV and Key Technology
Lee, Pan-Mook ; Yu, Son-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 7~13
Trends in the Cruising-Type AUVs Technologies
Jun, Bong-Huan ; Lee, Pan-Mook ; Lim, Yong-Kon ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 14~22
Design and Control of a Hovering Type AUV
Kim, Joon-Young ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 23~32
Introduction to Specific Purpose AUV and Applications
Yu, Son-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 33~40
Introduction to ROV and Motion Control & Signal Processing for ROV (Remotely Operated Vehicle) Hemire
Choi, Hyun-Taek ; Kim, Ki-Hun ; Lee, Pan-Mook ; Lee, Chong-Moo ; Jun, Bong-Huan ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 41~47
A Study on Laser-Assisted Machining Process of Silicon Nitride
Lim, Se-Hwan ; Lee, Jae-Hoon ; Shin, Dong-Sig ; Kim, Jong-Do ; Kim, Joo-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 48~56
In this paper, laser-assisted machining(LAM) has been employed to machine hot isostatically pressed (HIPed) Si3N4 work pieces. Due to little residual flaws and porosity, HIPed
work pieces are more difficult to machine compared to normally sintered
workpieces. In LAM, the intense energy of laser was used to enhance machinability by locally heating the workpiece and thus reducing yield strength. In experiments, the laser power ranges from 200W to 800W and the diameter of work pieces is 16mm. While machining, the surface temperature was kept nearly constant by laser heating except for a short period of rise time of max. 58 seconds. Results showed as feed rate increases the surface temperature of
workpieces decreases slightly, whereas the effect of depth of cut is disregardable. With a laser power of 800W, achievable maximal depth of cut as 0.7mm and feed rate was 0.03mm/rev.
Die Surface Texturing by Femtosecond Laser for Friction Reduction
Choi, Hae-Woon ; Shin, Hyun-Myung ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 57~63
Interface friction in blanking dies, cold forging and extrusion of aluminum alloys is a major cause of inefficient process. This paper describes an investigation of femtosecond laser texturing for reduction of interface friction on sliding surfaces in forming process. Femtosecond direct writing technology was used to fabricate a laser micro-machined die and to create microgroove patterns with varying size and density on metal forming dies. A systematic approach to find the optimum parameters and computer simulation comparison of friction coefficients are provided to study the relation of friction coefficients and die profiles. In metal forming tests, the effectiveness of various laser-machined patterns for enhancing interface lubrication is determined.
Ultra-precision Free-form Surface Grinding of WC Core
Park, Soon-Sub ; Hwang, Yeon ; Kim, Geon-Hee ; Won, Jong-Ho ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 64~71
Cylindrical lens core for optical transceiver was designed and machined. With the lens design data, WC asymmetric core surface data were generated for non-revolutional ultra-precision grinding. Grinding process for optimum machining conditions of target surface was studied in terms of surface roughness and form profile. We used experimental results to optimize turbine speed, feed-rate and depth of cut with durable grinding wheel wear. Ground WC cores were measured contact type profilers and verified.
Separation Algorithm for 2D Refractive Index Distribution and Thickness Measurement of Transparent Objects using Multi-wavelength Source
Lee, Kwang-Chun ; Ryu, Sung-Yoon ; Lee, Yun-Woo ; Kwak, Yoon-Keun ; Kim, Soo-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 72~78
We propose the separation algorithm to simultaneously measure two-dimensional refractive index distribution and thickness profile of transparent samples using three wavelengths. The optical system was based on the Mach-zehnder interferometer with LD (Laser Diode)-based multi-wavelength sources. A LCR (Liquid Crystal Retarder) was used to obtain interference images at four phase states and then the optical phase of the object is calculated by four-bucket algorithm. Experimental results with a glass rod are provided at the different wavelengths of 635nm, 660nm and 675nm. The refractive indices of the sample are distributed with accuracy of less than 0.0005 and the thickness profile of sample was cylindrical type. This result demonstrates that it is possible to separate refractive index distribution and thickness profile of samples in two dimensions using the proposed algorithm.
Precise Speed Control of Direct Drive PMSM for the Cogging Torque Measurement System
Park, Cheol-Hoon ; Son, Young-Su ; Ham, Sang-Yong ; Kim, Byung-In ; Yun, Dong-Won ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 79~86
Recently PMSM(Permanent magnet synchronous motor) are used for the various direct drive applications such as index table, telescope system and so on. Because the position/speed control performance of direct drive PMSM is directly affected by the torque ripple, there are lots of studies to reduce the cogging torque in the motor design stage. In order to verify the motor design, the reliable cogging torque measurement system is essentially required. The measured motor must be rotated in the constant speed under 1deg/sec so that the cogging torque profile is measured correctly. In this study, the cogging torque measurement system which uses the direct drive PMSM and the speed controller to rotate the measured motor in 0.1rpm(0.6deg/sec) has been developed. Simulink/xPC target was used for the controller and data acquisition system. Based on PI controller, DOB and AFC have been applied to eliminate the low frequency disturbances and the periodic speed ripple. The experimental results show the good performance of the speed regulation for the reference speed 0.1rpm and the reliable profile of the measured cogging torque by the developed speed controller.
A Study on the Development and Precise Performance Test of a Screw Type Flowmeter
Hwang, Jong-Dae ; Oh, Ji-Young ; Jung, Yoon-Gyo ; Lee, Sang-Ryul ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 87~95
This research introduces the efficient modeling and manufacturing method using reverse engineering combined with rotational simulation of a pair of screw and mill-turn machining realized a proposed NC program. Because previously developed model had insufficient flow measuring accuracy, we considered that matter in the aspect of method of modeling and performance test. For that reason we modified the modeling which could minimize a gab between male and female screw, and developed precise tester which consists of constant tank, flowmeter and load cell, etc., and then conducted the test for defining characteristic and accuracy of flowmeter and repeated same test 5-times. Consequently we could obtain satisfied measuring accuracy and reproducibility indicated in the catalog of master model. Hence we give our conclusion as to the validity of developing accurate screw type flowmeter using the proposed process such as reverse engineering, mill-turn machining and precise performance test.
Development of Humanoid Robot's Intelligent Foot with Six-axis Force/Moment Sensors
Kim, Gab-Soon ; Kim, Hyeon-Min ; Yoon, Jung-Won ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 96~103
This paper describes a humanoid robot's intelligent foot with two six-axis force/moment sensors. The developed humanoid robots didn't get the intelligent feet for walking on uneven surface safely. In order to walk on uneven surface safely, the robot should measure the reaction forces and moments applied on the sales of the feet, and they should be controlled with the measured the forces and moments. In this paper, an intelligent foot for a humanoid robot was developed. First, the body of foot was designed to be rotated the toe and the heel to all directions, second, the six-axis force/moment sensors were manufactured, third, the high-speed controller was manufactured using DSP(digital signal processor), fourth, the humanoid robot's intelligent foot was manufactured using the body of foot, two six-axis force/moment sensors and the high-speed controller, finally, the characteristic test of the intelligent foot was carried out. It is thought that the foot could be used for a humanoid robot.
Development of Wireless Device for Inspecting Crankshaft Deflection Using Linear Encoder
Kim, Jang-Kyu ; Lee, Min-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 104~111
A ship engine operator should compensate the crankshaft assembly of ship engine after inspecting crankshaft deflection error in the crank throw regularly to avoid engine vibration and abrasions. In the previous method, the operator enters the bed plate and measures crankshaft deflection using dial gauge on rotating crankshaft manually. However, this method can cause dangerous situation to the operator as well as uncomfortable in an inferior environment. In order to solve the problems, this paper studies the method which makes the operator measure the error outside of the bed plate. In this paper, it is suggested that BlueTooth wireless communication transfers the error data to the outer standing operator with digitalized crankshaft deflection inspection device developed in this paper. So, the wireless measurement system is developed and applied to a medium-speed marine engine through size-miniaturization. After applying test, the developed inspection device showed that it provides much safe and ease inspection method. Furthermore, in the result, the measuring accuracy is more improved.
A Study on Development of the High Precision Cam Measurement Apparatus and Analysis of Cam Manufacturing Error
Roh, Young-Hwa ; Lee, Choon-Man ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 112~119
Cam mechanisms are one of the most popular devices for generating irregular motion and are widely used in many automatic equipments, such as textile machinery, internal combustion engines and other automatic devices. In order to obtain the positive motion of follower by rotating cam, its shape should be correctly designed and manufactured. However, complex engineering tasks are required in a design and manufacturing of cams. And also, the manufacturing of general cam is demanded high costs. For the designing of cam, it must be decided that what kind of motion has to be transmitted to follower before selecting the curve of cam and designing profile of cam. However, even though the exact profile of cam is designed at the progress of design, if it doesn't have precision at the manufacturing progress, it's impossible to get expected result. We will develop cam simulation apparatus for measuring cam curve and get profile data before analyzing an error through comparison with design data of cam.
Temperature Control of Electric Furnaces using Adaptive Time Optimal Control
Jeon, Bong-Keun ; Song, Chang-Seop ; Keum, Young-Tag ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 120~127
An electric furnace, inside which desired temperatures are kept constant by generating heat, is known to be a difficult system to control and model exactly because system parameters and response delay time vary as the temperature and position are changed. In this study the heating system of ceramic drying furnaces with time-varying parameters is mathematically modeled as a second order system and control parameters are estimated by using a RIV (Recursive Instrumental-Variable) method. A modified bang-bang control with magnitude tuning is proposed in the time optimal temperature control of ceramic drying electric furnaces and its performance is experimentally verified. It is proven that temperature tracking of adaptive time optimal control using a second order model is more stable than the GPCEW (Generalized Predictive Control with Exponential Weight) and rapidly settles down by pre-estimation of the system parameters.
Design of a Variable-Stiffness Type Safety Joint for Service Robots
Jeong, Jae-Jin ; Chang, Seung-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 128~134
This paper aims to design a variable-stiffness type economical safety joint for service robots. The safety joint was designed to have a passive shock absorbing mechanism for protecting human from a catastrophic collision under service condition of robots. A simple mechanism composed of two action disks for switching the load transfer, a spring and a screw for pre-load was proposed. In order to evaluate the performance of the safety joint a testing platform which can carry out the static and impact tests was also designed and fabricated. From the test results, the designed safety joint was proved to have a variable load-carrying capacity and about 42% impact absorption capacity with simple manipulation of the control screw.
FE-analysis of Shrink Fits and Internal Clearance for Ball Bearing of Machine Tool
Kim, Woong ; Lee, Choon-Man ; Hwang, Young-Kug ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 135~141
The bearing clearance is influenced by shrink fit and thermal expansion during operation. The designer must take into account the reduction of clearance after installation to the interference fits, and thermal expansion must be considered. The purpose of this study is to grasp the internal clearance variation and behavior of a bearing which is a deep connected with fatigue life of bearing and performance of spindle through FEM(Finite Element Method). Finite element analysis is performed by using commercial code ANSYS according to variation of thermal condition and rotational speeds. This paper presents correct negative internal clearance according to temperature during operation. Furthermore, interrelation between thermal expansion and contraction are presented to maintain adequate contact force for three type of spindle system (HSK-A60, HSK-40E, HSK-32E). The influence of the centrifugal force and Internal clearance variation of bearing is studied to operating rotational speed.
Development and Application of Polymer-based Flexible Force Sensor Array
Hwang, Eun-Soo ; Yoon, Young-Ro ; Yoon, Hyoung-Ro ; Shin, Tae-Min ; Kim, Yong-Jun ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 142~149
This paper proposes and demonstrates novel flexible contact force sensing devices for 3-dimensional force measurement. To realize the sensor, polyimide and polydimethylsiloxane are used as a substrate, which makes it flexible. Thin-film metal strain gauges, which are incorporated into the polymer, are used for measuring the three-dimensional contact forces. The force sensor characteristics are evaluated against normal and shear load. The fabricated force sensor can measure normal loads up to 4N. The sensor output signals are saturated against load over 4N. Shear loads can be detected by different voltage drops in strain gauges. The device has no fragile structures; therefore, it can be used as a ground reaction force sensor for balance control in humanoid robots. Four force sensors are assembled and placed in the four corners of the robot's sole. By increasing bump dimensions, the force sensor can measure load up to 20N. When loads are exerted on the sole, the ground reaction force can be measured by these four sensors. The measured forces can be used in the balance control of biped locomotion system.
Removal of Nano-scaled Fluorescence Particles on Wafer by the Femtosecond Laser Shockwave
Park, Jung-Kyu ; Cho, Sung-Hak ; Kim, Jae-Gu ; Chang, Won-Seok ; Whang, Kyung-Hyun ; Yoo, Byung-Heon ; Kim, Kwang-Ryul ;
Journal of the Korean Society for Precision Engineering, volume 26, issue 5, 2009, Pages 150~156
The removal of tiny particles adhered to surfaces is one of the crucial prerequisite for a further increase in IC fabrication, large area displays and for the process in nanotechnology. Various cleaning techniques (wet chemical cleaning, scrubbing, pressurized jets and ultrasonic processes) currently used to clean critical surfaces are limited to removal of micrometer-sized particles. Therefore the removal of sub-micron sized particles from silicon wafers is of great interest. For this purpose various cleaning methods are currently under investigation. In this paper, we report on experiments on the cleaning effect of 100nm sized fluorescence particles on silicon wafer using the plasma shockwave occurred by femtosecond laser. The plasma shockwave is main effect of femtosecond laser cleaning to remove particles. The removal efficiency was dependent on the gap distance between laser focus and surface but in some case surface was damaged by excessive laser intensity. These experiments demonstrate the feasibility of femtosecond laser cleaning using 100nm size fluorescence particles on wafer.