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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
Editor in Chief :
Volume & Issues
Volume 18, Issue 12 - Dec 2001
Volume 18, Issue 11 - Nov 2001
Volume 18, Issue 10 - Oct 2001
Volume 18, Issue 9 - Sep 2001
Volume 18, Issue 8 - Aug 2001
Volume 18, Issue 7 - Jul 2001
Volume 18, Issue 6 - Jun 2001
Volume 18, Issue 5 - May 2001
Volume 18, Issue 4 - Apr 2001
Volume 18, Issue 3 - Mar 2001
Volume 18, Issue 2 - Feb 2001
Volume 18, Issue 1 - Jan 2001
Selecting the target year
Study on Parallel-Typed Robot and Machining Tool
Lee, Min-Ki ; Kim, Tae-Sung ; Lee, Won-Chul ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 9~18
Eclipse:A New Parallel Mechanism Platform
Kim, Jin-Sung ; Kim, Jong-Won ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 19~26
Fully Autonomous Calibration of Parallel Kinematic Machines Using a Constraint Link
Ryu, Je-Ha ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 27~33
Stiffness Matrix of a Fully Parallel Manipulator and Its Applications
Choi, Yong-Je ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 34~39
Development of the Small-displacement-movement of a Pneumatic piston and the Hybrid Control Algorithm for Precision Position Control
Roh, Chul-Ha ; Kim, Yeung-Shik ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 40~45
This paper proposes a methodology for the small-displacement-movement of a piston and develops a hybrid control algorithm for the precision position control of a pneumatic rodless cylinder. The pneumatic system uses the voltage-proportional solenoid valves to minimum valve switching since the on/off type valves are create diffculties for accurate position control and induce a lot of valve switching. For the accurate position control a methodology for the small-displacement-movement of the piston is developed and identified experimentally. The main consideration on the development of the hybrid control law is to eliminate a stick-slip phenomenon in the pneumatic control system. This paper addresses these critical issues and presents experimental results for the pneumatic control system.
Precision Control of a Torque Standard Machine Using Fuzzy Controller
Kim, Gab-Soon ; Kang, Dae-Im ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 46~52
This study describes the precision control of the torque standard machine using a self-tuning fuzzy controller. The torque standard machine should generate the accurate torque for calibrating a torque sensor. In order to reduce the relative expanded uncertainty of the torque standard machine, when a weight is hanged to the end of the torque arm for generating the torque, the sloped torque arm should be accurately controlled to the horizontal level. If the slope of the torque arm is larger from the inaccurate control, the uncertainty of the torque standard machine due to control will be larger. This applies the inaccurate torque to a torque sensor to calibrate, and the measuring error of the torque sensor generate from it. Therefore the torque arm of the torque standard machine is accurately controlled. In this paper, the self-tuning fuzzy controller was designed using a fuzzy theory, and the torque arm of the torque standard machine was accurately controlled. The control gain of the fuzzy controller, that is the membership function size of the error, the membership function size of the error change and the membership function size of the controller were determined from the self-tuning. The control results of the torque standard machine were the overshoot within 0.0076mm, the rise time within 16.70sec and the steady state error within 0.0076mm.
A Study on the Sway Control of a Crane Based on Gain-Scheduling Approach
Kim, Young-Bok ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 53~64
The gain-scheduling control technique is vary useful in the control problem incorporating time varying parameters which can be measured in real time. Based on these facts, in this paper the sway control problem of the pendulum motion of a container hanging on the trolly, which transports containers from a container ship to trucks, is considered. In the container crane control problem, suppressing the residual swing motion of the container at the end of acceleration, deceleration or the case of that the unexpected disturbance input exists is main issue. For this problem, in general, the trolley motion control strategy is introduced and applied. But, in this paper, we introduce and synthesize a new type of swing motion control system. In this control system, a small auxiliary mass is installed on the spreader. And the actuator reacts against the auxiliary mass, applying inertial control forces to the container to reduce the swing motion in the desired manner. In this paper, we assume that an plant parameter is varying and apply the gain-scheduling control technique design the anti-swing motion control system for the controlled plant. In this control system, the controller dynamics are adjusted in real-time according to time-varying plant parameters. And the simulation result shows that the proposed control strategy is shown to be useful to the case of time-varying system and, robust to disturbances like winds and initial sway motion.
A Study on PC-NC Based Aspherical Lens Polishing System with Minimum Translation Mechanism
Yang, Min-Yang ; Lee, Ho-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 65~71
The development process of the polishing system for the aspherical lens mold for opto-electronics industry is described. The system uses the method that polishing tool is scanned on the surface under PC-NC control for the aspherical lens mold. The two axes interpolation of the minimum translation mechanism is applied to give uniform working condition by motion analysis. An aspherical surface is divided into multiple sections and each dwell time is calculated from the polishing rate model based on the Preston equation. As result of form error compensation experiment, initial form error is decreased about 25% while an average value of surface roughness is also reduced successfully from 180nm to 19nm.
Development of Product Design Methodology for Assemblability and Disassemblability Considering Recycling
Mok, Hak-Soo ; Cho, Jong-Rae ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 72~84
This paper proposes a design methodology for customer, assembly and disassembly considering recycling. The disign process starts with the identification of customer needs, which are in turn converted into functional requirements. The concepts of Design for Customer(DFC), Design for Assembly(DFA), Design for Variety(DFV) and Design for Disassembly(DFD) are considered in the product design phases in order to decreas production variety and mass customization. And, a new module generation approach is developed for rearranging and clustering parts and subassemblies for disassembly and recycling. Based on the result of the module generation, a new configuration methodology is suggested to minimize the disassembly time or number of disassembly operations for recycling.
New Engineering J and COD Estimation Method for Circumferential Through-Wall Cracked Pipes-Combined Tension and Bending Load
Huh, Nam-Su ; Kim, Yun-Jae ; Kim, Young-Jin ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 85~90
In order to apply the Leak-Before-Break(LBB)concept to nuclear piping, accurate estimation of J-integral and crack opening displacement(COD) is essential for complex loading, such as combined tension and bending. This paper proposes a new engineering method to estimate J-integral and the COD for circumferential through-wall cracked pipes subject to combined tension and bending loading. The proposed method to estimate the COD is validated against three published pipe test data, generated from a monotonically increasing bending load with a constant internal pressure, which shows excellent agreements.
Frictional Contact Analysis of the Crack Surfaces Under the Compressive Loading
Kim, Bang-Won ; Kim, Young-Kweon ; Lee, Ki-Su ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 91~97
When a body including a crack inside is subjected to the compressive forces, the crack is closed and sliding occurs on the crack surfaces. In this work, a subsurface crack subjected to a static compressive load is analyzed with the finite element method considering friction on the crack surface. The friction on the crack surface is assumed to follow the Coulomb friction law, and a numerical method based on the finite element method and iterative method is applied in this work. The result is compared with those of ANSYS and references.
A Study of an OMM System for Machined Spherical form Using the Volumetric Error Calibration of Machining Center
Kim, Sung-Chung ; Kim, Ok-Hyun ; Lee, Eung-Suk ; Oh, Chang-Jin ; Lee, Chan-Ho ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 98~105
The machining accuracy is affected by geometric, volumetric errors of the machine tools. To improve the product quality, we need to enhance the machining accuracy of the machine tools. To this point of view, measurement and inspection of finished part as error analysis of machine tools ahas been studied for last several decades. This paper suggests the enhancement method of machining accuracy for precision machining of high quality metal reflection mirror or optics lens, etc. In this paper, we study 1) the compensation of linear pitch error with NC controller compensation function using laser interferometer measurement, 2) the method for enhancing the accuracy of NC milling machining by modeling and compensation of volumetric error, 3) the spherical surface manufacturing by modeling and compensation of volumetric error of the machine tool, 4) the system development of OMM without detaching work piece from a bed of machine tool after working, 5) the generation of the finished part profile by OMM. Furthermore, the output of OMM is compared with that of CMM, and verified the feasibility of the measurement system.
A Study on the Grinding Characteristics of the Quartz
Lim, Jong-Go ; Ha, Sang-Baek ; Kim, Sung-Hun ; Choi, Hwan ; Lee, Jong-Chan ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 106~111
This study reports the grinding characteristics of quartz. Grinding experiments were performed at various grinding conditions including wheel mesh, table speed and depth of cut. The grinding forces and specific grinding energies were measured. Surface roughness was also measured with tracer and the ground surfaces were observed with SEM. A new parameter SDR(Surface roughness Direction Ratio) is proposed to characterize the grinding mechanisms of quartz. A set of experiments was performed to verify the effectiveness of the suggested parameter. The experimental results indicate that the ductile mode is the dominant material removal mode at the grinding conditions which show the higher value of SDR whereas the material is removed by brittle fracture in a lower value of SDR value increases with wheel mesh size.
A Study on the Cutting Force and Machining Error on the Inclined Plane in Ball-end Milling
Doo, Seung ; Hong, Joo-Won ; Suh, Nam-Sub ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 112~119
In modern manufacturing, many products that have geometrically complicated features, including three-dimensional sculptured surfaces, are being designed and produced to meet various sophisticated functional specifications. The cutting force is required not only for the design of machine and cutting tools, but also for the determination of the cutting conditions for the various machining operations. The ball-end mill is deflected by the cutting force and, the tool deflection is one of the main reasons of the machining errors on a free-form surface. Hence, The cutting force generated in the ball-end milling is the most important property of the machining. The purpose of this study is to find the characteristics of the cutting force in inclined plane and the resultant machining errors in the ball-end milling process. Although the depth of cut is constant in the inclined plane, the cutting force area varies due to the hemisphere of the ball-end mill.
A Study on Axial Collapse Characteristics of Spot Welded Double-Hat Shaped Section Members by FEM
Cha, Cheon-Seok ; Kim, Young-Nam ; Yang, In-Young ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 120~126
The widely used spot welded section members of vehicles are structures which absorb most of the energy in a front-end collision. In front-end collision, sufficiently absorbed in the front parts, the impact energy does not reach the passengers. Simultaneously, the frame gets less damaged. This structures have to be very stiff, but collapse progressively to absorb the kinetic energy as expected. In the view of stiffness, the double-hat shaped section member is stiffer than the hat shaped section member. In progress of collapse, the hat shaped section member is collapsing progressively, but the double-hat shaped section member does not due to stiffness. An analysis on the hat shaped section member was previously completed. This paper concerns the collapse characteristic of the double-hat shaped section member. In the program system presented in this study, an explicit finite element code, LS-DYNA3D is adopted for simulating complicate collapse behavior of double hat shaped section members with respect to spot weld pitches. And comparing with the results from the quasi-static and impact experiment, the simulation has been verified.
Influence of Current Waveform on Anode Erosion in Wire Electric Discharge Machining
Cho, Sung-San ; Oh, Jin-Hyuk ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 127~133
The effects of triangular and rectangular discharge current waveforms on anode erosion in wire electric discharge machining is investigated based on heat transfer analysis of half-space subject to time and space-dependent heat flux. The thermal load on the anode is simulated by a hear flux that is calculated from time-dependent discharge channel radius and energy. Evolution of the melting front during discharge, the molten volume at the experimental result for qualitative verification of the analysis. It is demonstrated that the triangular current waveform is more efficient in eroding the anode than the rectangular one.
Calculation of Stress Intensity Factor in 2-D Using
-Integral for a Rectilinear Elastic Anisotropic Body
An, Deuk-Man ; Choi, Chang-Yeon ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 134~142
(k=1,2) in the rectilinear anisotropis body in 2-D were determined using Lekhnitskii formalism. The relationship between
and stress intensity factors are implified by the important equation between elastic compliance. The numerical evaluation of stress intensity factor for the single edge crack in mixed mode is determined by superposing known exact solutions.
Cutting Force Variation of Inconel 718 in Up and Down Endmilling with Different Helix Angles.
Lee, Young-Moon ; Lee, Sun-Ho ; Tae, Won-Ik ; Kwon, O-Jin ; Choi, Bong-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 143~148
In this study, a mechanistic model of cutting force components in up and down end milling process is presented. Using this cutting force model of 4-tooth endmills with various helix angles, cutting force variation of inconel 718 has been predicted. Predicted values of cutting force components are coincide well with the measured ones. As helix angle increases, overlapping effects of the active cutting edges increase. In up endmilling the magnitudes of radial and feed cutting force componts FX and FY are lowest when the helix angle is
, but in down endmilling the magnitudes of these values increase slightly as helix angle becomes large.
A Study on the Development of Image Processing Measurement System for Structural Analysis by Optical Non-contact Measurement
Jang, Soon-Suck ; Kim, Koung-Suk ; Hong, Jin-Who ; Choi, Ji-Eun ; Kang, Ki-Soo ; Kim, Dal-Woo ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 149~154
This study discusses a non-contact optical technique, electronic speckle pattern interferometry(ESPI), that is well suited for a deformation measurement of structure. Phase shifting method and unwrapping method have used to make deformation quantitative widely. In this paper, a previous numerical formula for phase shifting method is reconstructed in addition to least square fitting method to improve sensitivity and phase unwrapping based on vertical-horizontal scanning method is applied to analyze in-plane and out-of-plane deformation quantitatively.
Improvement of the Surface Roughness by Changing Chamfered Angle of the Insert in Face Milling
Kwon, Won-Tae ; Lee, Seong-Sei ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 155~160
A milling process with 45 degree chamfered inserts produces a perfect flat surface only in theory. It is due to many unwanted factors including thermal effect, dynamic effect, the problem of the controller used and the problem of accuracy of the machine tool. In this study, introduced is a method to improve the surface roughness by redesigning of the chamfer angle of the insert, which traditionally has been 45 degree. First, the relationship between the fixed machine coordinate and the relative coordinate on the insert is derived. This transfer matrix is used to determine the new insert angle to maximize the flatness of the machined surface. A newly designed insert is manufactured, and used to carry out the experiment. It is proved that she insert designed by the proposed method produced a much flatter surface than a traditional one.
Fabrication and Characteristic Evaluation of a Flexible Tactile Sensor Using PVDF
Yu, Kee-Ho ; Yun, Myung-Jong ; Kwon, Tae-Gyu ; Lee, Seong-Cheol ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 161~166
The prototype of a tactile sensor with
taxels using PVDF was fabricated. The electrode patterns of the thin Cu tape are attached to the 28
thickness PVDF using conductive adhesive and covering the sensor using polyester film for insulation. The structure of the sensor is flexible and the fabrication procedure is easy relatively. Also the output characteristics of the sensor was nearly linear with 8% deviation. The signals of a contact pressure to the tactile sensor are sensed and processed through A/D converter, DSP system and personal computer. The reasonable performance for the detection of contact shape and force distribution was verified through the experiment
Design and Development of the Simulated Die casting Process by using Rapid Prototyping
Kim, Ki-Don ; Yang, Dong-Yol ; Jeong, Jun-Ho ; Park, Tae-Kwon ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 167~173
The simulated die-casting process in which the traditional plaster casting process is combined with Rapid Prototyping technology is being used to produce AI, Mg, and Zn die-casting prototypes. Unlike in the die-casting process, molten metal in the conventional plaster casting process is fed via a gravity pour into a mold and the mold does not cool as quickly as a die-casting mold. The plaster castings have much larger and grosser grain structure as compared with the normal die-castings and the thin walls of the plaster mold cavity may not be completely filled. Because of lower mechanical properties induced by the large grain structure and incomplete filling, the conventional plaster casting process is not suitable for the trial die-casting process to obtain quality prototypes. In this work, an enhanced trial die-casting process has been developed in which molten metal in the plaster mold cavity is vibrated and pressurized simultaneously. Patterns for the casting are made by Rapid Prototyping technologies and then plaster molds, which have a runner system, are made using these patterns. Pressurized vibration to imparted molten metal has made grain structure of castings much finer and improved fluidity of the molten enough to obtain complete filling at thin walls which may not be filled in the conventional plaster casting process..
Development of Rapid Manufacturing Process by Machining with Automatic Filling
Shin, B. S. ; Yang, D. Y. ; Choi, D. S. ; Lee, E. S. ; Hwang, K. H. ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 174~178
In order to reduce the lead-time and cost, recently the technology of rapid protoyping and manufacturing(RPM)has been widely used. Machining process is still considered as one of the effective RPM methods that have been developed and currently available in the industry. It also offers practical advantages such as precision and versatility. Some considerations are still required during the machining process. One of the most important points is fixturing. There should be an effective method of fixturing since the fixturing time depends on the complexity of geometry of the part to be machined. In this paper, the rapid manufacturing process has been developed combining machining with automatic filling. The proposed fixturing technique using automatic filling can be widely applicable to free surface type of product such as a fan. In the filling stage, remeltable material is chosen for the filling process. An automatic set-up device attachable to the table of the machine has also been developed. The device ensures the quality during a series of machining operations. This proposed process has shown to be a useful method to manufacture the required products with the reduced the response-time and cost.
Prediction of Welding Pressure in the Non Steady state Porthole Die Extrusion of AI7003 Tubes
Jo, Hyung-Ho ; Lee, Sang-Gon ; Lee, Seon-Bong ; Kim, Byung-Min ;
Journal of the Korean Society for Precision Engineering, volume 18, issue 7, 2001, Pages 179~185
Porthole die extrusion is profitable to manufacture long tube with hollow section. The material through portholes is gathered within chamber and welded under high pressure. This weldability which classifies the quality of tube product is affected by several variables and die shape. But, porthole die extrusion has been executed on the experience of experts due to the complicated die assembly and complexity of metal flow. Analytic approaches that are useful in profitable die design and in the improvement of productivity are inevitably demanded. Therefore, the objective of this study is respectively to analyze the behavior of metal flow and to determine welding pressure of hot extrusion product according to the various billet temperature, bearing length and tube thickness by FE analysis and its results are compared with tube expanding tests.