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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 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
A study on the Finishing Characteristics of Ultra-precision System
Bae, Myung-Il ; Kim, Hong-Bae ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 11~16
In this study, Ultra-precision finishing system using micro abrasive film experimented using experimental variable film feed speed and grinding speed and structural steel(SM45C) with respect to 12~3
micro abrasive film. the result are follows; (1) Experimental condition must setup dissimilar about each micro abrasive film. (2) To measurement deviation the smallest machined condition are 20mm/min in 12
, 5mm/min and 15mm/min in 9
, 5mm/min in 3
in film feed speed. (3) To measurement deviation the smallest machined condition are 180m/min in 12
, 84m/min in 9
, 56 and 84m/min in 5
, 104m/min in 3
in grinding speed.
Adaptive Fuzzy Sliding Mode Control of a Direct Drive Motor
Kim, Young-Tae ; Lee, Dong-Wook ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 17~24
Lane and Obstacle Recognition Using Artificial Neural Network
Kim, Myung-Soo ; Yang, Sung-Hoon ; Lee, Sang-Ho ; Lee, Suk ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 25~34
In this paper, an algorithm is presented to recognize lane and obstacles based on highway road image. The road images obtained by a video camera undergoes a pre-processing that includes filtering, edge detection, and identification of lanes. After this pre-processing, a part of image is grouped into 27 sub-windows and fed into a three-layer feed-forward neural network. The neural network is trained to indicate the road direction and the presence of absence of an obstacle. The proposed algorithm has been tested with the images different from the training images, and demonstrated its efficacy for recognizing lane and obstacles. Based on the test results, it can be said that the algorithm successfully combines the traditional image processing and the neural network principles towards a simpler and more efficient driver warning of assistance system
A Study on Evaluation of Machinability using cuter Runout in Ball-end Milling
Kim, Byoung-Kook ; Park, Hee-Bum ; Lee, Deug-Woo ; Kim, Jeong-Suk ; Jung, Yoong-Ho ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 35~44
The performance of interrupted cutting operations like milling is consideraly affected by cuter runout. In this study, cutter runout is selected as an important machining parameter for evaluation of machinability in ball-end milling and caused from misalignments of tool and holder, unbalanced mass of parts and tool deflection under machining. To evaluate the machinability due to cutter runout, the rotating accuracy of spindle, cutting force and surface roughness are measured. The rotating characteristics of spindle in each revolution speed were investigated by cutter runout in freeload. The predicted surface form of workpiece by measuring cutter runout data was compared with real surfaces. The results show that measuring runout with high response gap sensor is useful for studying the phenomenon of high-speed machining and the monitor surface form using in-process runout measurements in ball-end milling is possible.
Development of Online Realtime Positioning Error Compensation System for CNC Machine Tools
Chung, Chae-Il ; Kim, Jong-Won ; Nam, Weon-Woo ; Lee, Sang-Jo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 45~52
The online realtime positioning error compensation system 'SKY-PACS' is developed to correct geometric errors, thermal errors and tool deflection errors induced by cutting forces on the vertical machining center. 'SKY-PACS' communicates position commands and position compensation signals with the CNC controller at 100Hz, which is CNC control frequency. So the compensation procedure can be applied during axis movement. Using 'SKY-PACS', Maximum 1 axis positioning accuracy was corrected from 5
and the squareness error of X-Y table was corrected from 51
/m to below 4
/m. The error compensation under the cutting condition is carried out by ISO10791-7. And the measurement of test-pieces shows that the roundness is corrected rom 8
to below 5
Comparison of In-Plane Measurement of Phase-Shifting with Time-Average Method
Kim, Kyoung-Suk ; Kim, Dong-Iel ; Jung, Hyun-Chul ; Kang, Ki-Soo ; Lee, Chan-Woo ; Yang, Seung-Pil ; Jarng, Soon-Suck ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 53~58
Even I the Electronic Speckle Pattern Interferometry(ESPI) method that measure the strain of object within wavelength of light is less visibility than Holographic Interferometry(HI) method, the merits of application, convenience and time-save have made the method practical in industry. However, the existing ESPI methods that are based on dual-exposure, real-time and time-average method have difficulties for accurate measurement, due to irregular intensity and shake of phase. Recently, in order to solve this problem, phase shifting method have been proposed. In this method, the path of reference light in interference is shifted to make improvement in distinction and precision. But this method includes too many noise, caused by the problem of relationship between object and phase. Therefore, a method to reduce noise muse be introduced. In this paper, least square fitting method is proposed. As results, the phase-map is influenced by precise phase shifting and current of notes and speckle pattern obtained by phase shifting method is improved on the existing method driven from time-average method.
A Study of Using FDM/ABS Parts as Wax-Pattern Substitutes in the Investment Casting Process
Choi, Doo-Sun ; Shin, Bo-Sung ; Kim, Joo-Han ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 59~67
The lead time for new products is very limited in the current manufacturing processes, therefore the Rapid Prototyping process has been introduced and generally used in the industry. Fused Deposition Manufacturing (FDM) is one of the most common methods in this field. In the FDM process, the patterns are made of Wax of ABS and ABS shows better quality of the patterns. To date, the FDM/ABS patterns are used in investment casting for making silicon moulds to produce was patterns because it is very difficult to dewax FDM/ABS directly. The aim of this paper was to propose a feasibility of using FDM/ABS parts as wax-pattern substitutes in the investment casting process. The effects of casting conditions, such as pre-heat temperature and casting temperature, are provided. Comparisons with the conventional investment casting processes using the wax-patterns under the same prototype are made. Lead-time and saving cost are discussed in using FDM/ABS parts as was-pattern substitutes compared with the products from other rapid prototype systems.
A development of the Process Capturing and Sharing System for an Effective Collaborative Design
Han, Jin-Teck ; Lee, Soo-Hong ; Park, Sam-Jin ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 68~79
This paper describes an approach to collaborative design which focuses on the effects of individual activities on the overall design process. We utilize a new process modeling tool to define the process and then analyze and refine the process based on critical paths. This information is then shared over the Internet with all participants. The goal of this system is to detect critical errors at initial design stage and guide the designers to make better decisions based on the knowledge of the overall process. This system enables participating designers to publish his local process through an Internet bulletin board. Other members of the team can then provide feedback based on how the proposed process impacts their activities. The system provides a context-rich, persistent forum for collecting, preserving, and refining corporate expertise of the team. For example, designers can select any process from the bulletin board and use it as a template for his current project and then use it to maintain his own design history. This paper is based on the process modeling concepts of Design Roadamap and describe several key extensions in the area of CPM calculations and collaborative interfaces.
Automatic Focusing Vision System for Inspection of Size and Shape of Small Hole
Han, Moon-Yong ; Han, Hern-Soo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 80~86
Since the quality of the coated wires is in various applications dependant on the coating depth, accuracy of hole size of dies used for coating wires must be maintained precisely, in general within one micron. This paper proposes a new vision system which measures automatically the size and shape of small holes having diameters less than 1mm within an error limit of 1 micron. To quickly obtain the focused image, this paper proposes an estimation method of the camera position using only a couple of defocused hole images. It measures the distributions of light intensity around the image boundary and decides the direction and distance of a camera motion. The proposed system measures the size, shape distortion, inclination of the hole against the axis of the dies structure, to decides the acceptability of the dies for use. The proposed algorithm has been implemented using a cheap 640
480 image system and has shown an average size error of 1micron when measuring the dieses having 0.1mm to 1.0mm diameters. It can be applied to the inspection of the size and position of holes in PCB, too.
Characteristics of Noise Attenuation with the Variation of Flow Condition and Hole Shape of Perforated Intruding Tues in Muffler
Jung, Jin-Nyon ; Kim, Won-Jin ; Cho, Bum-Rae ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 87~93
To propose a useful modelling method for an actual muffler, the noise attenuation effects of muffler was investigated according to the flow condition and the hole shape of tubes. In this work, the finite element method was used to calculate the transmission loss of muffler, The noise attenuation characteristics of four different types of muffler in the hole shape of tubes were compared mutually to find a more simple equivalent model. Analytical results showed that the overall value of transmission loss increases and the peaks of transmission loss curve shift to the low frequency with mean flow for the given muffler, Also the noise attenuation characteristics of the equivalent model having the split holes is almost the same as those of the actual muffler having many circular holes.
Machining Rate and Electrode Wear Characteristics in Micro-EDM of Micro-Holes
Kim, Gyu-Man ; Kim, Bo-Hyun ; Chu, Chong-Nam ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 94~100
Micro-EDM is widely used in machining of miro-parts such as micro-shafts and micro-holes. In order to select proper machining conditions and to reduce the machining time, it is necessary to understand machining characteristics under various machining conditions. Micro-hole machining tests were performed with round shape electrodes with different capacitances and voltages of the power source. The effects of the electrode rotational speed and diameter on the machining rate were also observed. From the experimental results, it was found that capacitance and voltage have significant effects on machining rate and the machined surface integrity. With higher capacitance and higher voltage, higher machining rate was observed together with poorer surface integrity. The electrode diameter was also found to have an effect on the machining rate and electrode wear.
An Experimental Study on Optimization of Blank Shape in Elliptical Deep Drawing Process
Park, Dong-Hwan ; Choi, Byung-Keun ; Park, Sang-Bong ; Kang, Sung-Soo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 101~108
Most of researches for deep drawing process have been performed on the formability of axisymmetric blank, but there is an insufficient study on the formability of non-axisymmetric blank. In addition, the conventional blank shape has been determined by the trial-and-error method using industrial experience and post processing test. Therefore only approximated shape of the blank can be presented. In this study, the optimal blank shape and concrete drafting method in deep drawing process with biaxisymmetric elliptical shape is proposed. Through the deep drawing experiment, it is found that the optimal blank shape gives the most uniform thickness of the products in the first process
Sliding Mode Adaptive Control of the Gunner's Primary Stabilized Head Mirror
Keh, Joong-Eup ; Sung, Ki-Jong ; Lee, Won-Gu ; Lee, Man-Hyung ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 109~117
In this paper, a direct adaptive control, based on Lyapunov Function Candidate, is applied to a nonlinear Gunner's Primary Stabilized Head Mirror system to derive a parameter adaptation scheme; furthemore, a nonlinear sliding mode control, but also compensating the error in identification of the parameters which are even varying of have uncertain values. The performance of the adaptive controller is determined by the tracking ability to a desired model under some disturbances and the slowly varying parameters of the system. Both adaptive scheme and sliding mode play an important fole in the improvement of the nonlinear system control.
Effects of Flange Joint on the Dynamic Characteristics of the External Cylindrical Grinding Wheel Spindle
Kim, Sun-Min ; Ha, Jae-Hoon ; Lee, Sun-Kyu ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 118~125
In the grinding process, generally, the exciting forces with high frequency can be generated due to the wheel wear and the grinding process. As the grinding speed increases, the precise investigation about the wheel dynamic characteristics is required. Conventionally the wheel-spindle has been considered with lumped model in dynamic modeling. With this lumped model, the significant mode resulted from the shell mode of wheel can be readily ignored. This paper suggests the new analysis model which includes the shell mode of wheel in modeling the wheel-spindle assembly. Furthermore, based on the suggested model, the effects of the bolt tightening force and the taper tightening force on the dynamic properties are investigated by the finite element modal analysis and the experimental method. As a result of investigation, the shell mode vibration of wheel affects the dynamic characteristics of the spindle assembly. Also, the vibration modes of the spindle assembly are significantly affected by the joint tightening forces.
A Study on the Synthesis of Four-Bur Linkage Generating Automatic Path by Using B-Spline Interpolation
Kim, Jin-Su ; Yang, Hyun-Ik ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 126~131
Up until now, it is said that no satisfactory computer solutions have been found for synthesizing four-bar linkage based on the prescribed coupler link curve. In our study, an algorithm has been developed to improve the design synthesis of four-bar linkage automatically generating prescribed path by using B-spline interpolation. The suggested algorithm generates the desired coupler curve by using B-spline interpolation, and hence the generated curve approximates as closely as to the desired curve representing coupler link trajectory. Also, when comparing each generated polygon with the control polygon, rapid comparison by applying convex hull concept. finally, optimization process using ADS is incorporated into the algorithm based on the 5 precision point method to reduce the total optimization process time. As for examples, three different four-bar linkages were tested and the results showed the effectiveness of the algorithm.
Human-Robot Collaboration Work Via Human Impedance Estimation
Suh, Dong-Soo ; Hong, Suk-Kyu ; Lee, Byung-Ju ; Suh, Il-Hong ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 132~140
This paper treats the estimation of human impedance and their application to human-robot collaboration work. Initially, we perform an experiment at which the human becomes a slave and the robot behaves like a master having F/T sensor on its end. The human impedance expressed in terms of mass, damping, and stiffness properties are estimated based on the force data measured by F/T sensor and the commanded position data of the robot. To show the effectiveness of the estimated human impedance, we perform the second experiment at which the roles of the human and the robot are reversed. It is shown that the robot using the estimated human impedance follows the trajectory commanded by human very smoothly.
The Quality Assurance Technique of Resistance Spot Welding Pieces using Neuro-Fuzzy Algorithm
Kim, Joo-Seok ; Choo, Youn-Joon ; Lee, Sang-Ryong ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 141~151
The resistance Spot Welding is widely used in the field of assembling the plates. However we don't still have any satisfactory solution, which is non-destructive quality evaluation in real-time or on-line, against it. Moreover, even though the rate of welding under the condition of expulsion has been high until now, quality control of welding against expulsion hasn't still been established. In this paper, it was proposed on the quality assurance technique of resistance spot welding pieces using Neuro-Fuzzy algorithm. Four parameters from electrode separation signal in the case of non-expulsion, and dynamic resistance patterns in the case of expulsion are selected as fuzzy input parameters. The parameters consist of Fuzzy Inference System are determined through Neuro-Learning algorithm. And then, fuzzy Inference System is constructed. It was confirmed that the fuzzy inference values of strength have within
4% error specimen in comparison with real strength for the total strength range, and the specimen percent having within
1% error was 88.8%. According to KS(Korean Industrial Standard), tensile-shear strength limit for electric coated of zinc is 400kgf/mm2. Judging to the quality of welding is good or bad, according to this criterion and the results of inference, the probability of misjudgement that good quality is valuated into poor one was 0.43%, on contrary it was 2.59%. Finally, the proposed Neuro-Fuzzy Inference System can infer the tensile-shear strength of resistance spot welding pieces with high performance for all cases-non-expulsion and expulsion. And On-Line Welding Quality Inspection System will be realized sooner or later.
A Study on Stress Singularities for V-notched Cracks in Pseudo-isotropic and Anisotropic Dissimilar Materials
Cho, Sang-Bong ; Kim, Jin-Kwang ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 152~163
The problem of eigenvalue and eigenvector for v-notched cracks in pseudo-isotropic and anisotropic dissimilar materials was obtained to discuss stress singularities from traction free boundary and perfect bonded interface conditions assuming like the form of complex stress function for v-notched cracks in an isotropic material. Eigenvalues were solved by a commercial numerical program, MATHEMATICA. The relation between wedged angle and material property for eigenvalue,
indicating stress singularities of v-notched cracks in pseudo-isotropic and anisotropic dissimilar materials was examined.
A CAE Approach for Net-Shape Automobile Stamping Components of Aluminum Alloy
Choi, Han-Ho ; Ku, Tae-Wan ; Hwang, Sang-Moon ; Kang, Beom-Soo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 164~171
An optimum blank design technology is required for near-net of net-shape cold forming using sheets. Originally, the backward tracing scheme has been developed for preform design in bulk forming, and applied to several forming processes successfully. Its key concept is to trace backward from the final desirable configuration to an intermediate preform of initial blocker. A program for initial blank design in sheet forming which contains the capabilities of forward loading simulation by the finite element method and backward tracing simulation, has been developed and proved the effectiveness by applying to a square cup stamping process. In the blank design of square cup stamping, the backward tracing program can produce an optimum blank configuration which forms a sound net-shape cup product without machining after forming. Another general application appears in the blank design of a cup stamping with protruding flanges, one of typical automobile components. The blank configurations derived by backward tracing simulation have been confirmed by a series of loading simulations. The approach or decision of an initial blank configuration presented in this study will be a milestone in fields of sheet forming process design.
On-Machine Measurement of Sculptured Surfaces Based on CAD/CAM/CAI Integration : I. Measurement Error Modeling
Cho, Myeong-Woo ; Lee, Se-Hee ; Seo, Tae-Il ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 172~181
The objective of this research is to develop a measurement error model for sculptured surfaces in On-Machine Measurement (OMM) process based on a closed-loop configuration. The geometric error model of each axis of a vertical CNC Machining center is derived using a 4
4 homogeneous transformation matrix. The ideal locations of a touch-type probe for the scupltured surface measurement are calculated from the parametric surface representation and X-, Y- directional geometric errors of the machine. Also, the actual coordinates of the probe are calculated by considering the pre-travel variation of a probe and Z-directional geometric errors. Then, the step-by-step measurement error analysis method is suggested based on a closed-loop configuration of the machining center including workpiece and probe errors. The simulation study shows the simplicity and effectiveness of the proposed error modeling strategy.
A Study on the Grinding Characteristics of Ceramics
Ha, Sang-Baek ; Jeon, Young-Kil ; Choi, Whan ; Lee, Jong-Chan ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 182~186
Structural ceramics such as
, SIC, and
are difficult to grind materials because of their high hardness and brittleness. They are normally ground in brittle mode, but it is possible to be ground in ductile mode depending upon the grinding conditions. In this paper an experimental investigation has been carried out to see the relationship between the grinding energy and grinding mode. It has been found that the ductile mode grinding consumes more grinding energy than the brittle mode grinding. Thus, the grinding conditions of the higher specific grinding energy leads to the plastic deformation in the ground surface of workpiece and results in the better surface finish.
A Study on the Effects of Root Gap on Mechanical Properties and Microstructure of Weldment
Lee, Won-Kun ; Jang, Gyoung-Boc ; Kang, Sung-Soo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 187~193
Dimensional difference by welding deformation is usually occurred at steel bridge manufacturting or multi-pass welding used at joining of thick plates. Be this, root gap out of standard is frequently developed at butt weld joints. For example, although standard root gap below 6mm at butt weld joints of plates under 15mm thickness, maximum 30mm root opening is developed at the weld field. At this case, 24mm parts out of standard is generally built up. But, there are no accumulated data and restriction about this built up welding pars. In this study, therefore, the accumulation of data for built up parts and the verification of the mechanical properties of weld part as root gap is performed. It is included that tensile, bending, impact, hardness test and microstructural review for each welding specimen of 0mm, 6mm, 30mm root opening.
Analysis of 2-Dimensional Object Recognition Using discrete Wavelet Transform
Park, Kwang-Ho ; Kim, Chang-Gu ; Kee, Chang-Doo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 194~202
A method for pattern recognition based on wavelet transform is proposed in this paper. The boundary of the object to be recognized includes shape information for object of machine parts. The contour is first represented using a one-dimensional signal and normalized about translation, rotation and scale, then is used to build the wavelet transform representation of the object. Wavelets allow us to decompose a function into multi-resolution hierarchy of localized frequency bands. The recognition of 2-dimensional object based on the wavelet is described to analyze the shape of analysis technique; the discrete wavelet transform(DWT). The feature vectors obtained using wavelet analysis is classified using a multi-layer neural network. The results show that, compared with the use of fourier descriptors, recognition using wavelet is more stable and efficient representation. And particularly the performance for objects corrupted with noise is better than that of other method.
Multiphase Homodyne Laser Interferometer with Four Bucket
Park, Yoon-Chang ; Jeong, Kyung-Min ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 203~208
By tilting the reference mirror of Twynman-Green interferometer having a reference mirror and a moving mirror, firinge pattern composed of bright and dark parallel lines can be obtained and the fringe pattern is shifted according to the displacement of the mowing mirror. Several studies are executed for displacement measurement by detecting the intensity of the fringe with photo-diodes having small detecting area. In this study, to improve the sensitivity and robustness, the intensity of fringe is detected by using a large-area quadratic photo-diode masked with a grating panel having four kinds of binary grating having phase-difference of 0,
/4. The phase of the fringe is calculated with a simple 4-buckets algorithm. A experimental result shows that standard deviation of 5.653 nm is obtained comparing with a capacitive type gap sensor having nearly 1 nm accuracy.
A Study on Passive Force Control of a Flexible Manipulator
Kim, Jin-Soo ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 209~216
Development of an Expert System for Diagnosing Machine Tool Failures
Seo, Dong-Kyu ; Kang, Mu-Jin ;
Journal of the Korean Society for Precision Engineering, volume 16, issue 10, 1999, Pages 217~224
Trouble shooting of modern machine tools equipped with sophisticated electronic as well as mechanical parts is so difficult that it is usually depends upon the experience and accumulated knowledge of the diagnosing persons. On the other hand, tool users are scattered in wide area, which makes it expensive for a machine tool maker to run a vast service network. An unmanned diagnosis system to which users can have access at all times could be an efficient alternative. For this purpose, a rule-based expert system for diagnosing machine tools is developed. This paper describes the structure of diagnostic knowledge, the rule firing mechanism, the diagnosis flow, and user query process. An example shows the feasibility of problem solving on site without help of a service expert from machine tool maker.