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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
Editor in Chief :
Volume & Issues
Volume 13, Issue 12 - Dec 1996
Volume 13, Issue 11 - Nov 1996
Volume 13, Issue 10 - Oct 1996
Volume 13, Issue 9 - Sep 1996
Volume 13, Issue 8 - Aug 1996
Volume 13, Issue 7 - Jul 1996
Volume 13, Issue 5 - May 1996
Volume 13, Issue 4 - Apr 1996
Volume 13, Issue 3 - Mar 1996
Volume 13, Issue 1 - Jan 1996
Selecting the target year
Machine Tool Technology; The Present and the Future(13)
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 11~20
Nano-technology after the year 2000
Ken Stout ; Liam Blunt ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 21~23
Just as the transistor changed the face of electrical engineering and heralded the electronic and microprocessor era, a new technology, still in its infancy is likely to have an even larger impact on industry and society alike. This new technology which has already begun to make its impact on modern technology is called nano-technology. Nano-technology, derived from the Greek word, meaning - Dwarf, is related to the ability to manufacture, fabricate and measure in the nanometre precision range, which is 10
parts of metre, a dimension which makes the diameter of a human hair appear huge by comparison.
Development of a Programming System for Sequential Control Using a Graphic Organization Language
K.H. Kuk ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 24~33
PLCs are vital components of modern automation systems, which have penetrated into almost every industry. Many industries have a demand for facilitation of PLC programming. In this study, a programning system for sequential control is developed on a personal computer. This programming system consists of two main parts, a GRAFCET editor and a GRAFCET compiler. The GRAFCET editor enables us to model an actual sequential process by a GRAFCET diagram. This GRAFCET editor is developed by the menu-driven method based on specific menus and graphic symbols. The GRAFCET compiler consists of two parts, a GRAFCET parser and a code generator. The possible errors in a drawn GRAFCET diagram are first checked by the GRAFCET parser which generates finally an intermediate code from a verified CRAFCET diagram. Then the intermediate code is converted into a control code of an actual sequential controller by the code generator. To show the usefulness of this programming system, this system is applied to a pneumatically controlled handling robot. For this robot, a Z-80 microprocessor is used as the actual sequential controller.
A Development of Task-oriented Programming System for the Application of Robot
Park, H.S. ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 34~42
Robot programming has been discussed in detail during the recent years. Numerous studies in particular presented relevance, solution concepts and implementation of off-line programming. In this paper a new user-friendly robot programming method is introduced, which permits the implicit description and programming of assembly process. On the functional level of programming, the assembly processes are described in terms of their operational functions. On the language level, the individual functions are then translated into commands for the robots.
Computer-Aided Process Planning System of Cold Forging and its Verification by F.E. Simulation
Lee, E.H. ; Kim, D.J. ; Park, J.C. ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 43~52
This paper describes interactive computer procedures for design the forming sequences in cold forging. This system is implemented on the personal computer and its environment is a commercial AutoCAD system. The programming language. AutoLISP, was used for the configuration of the system. Since the process of metal forming can be considered as a transformation of geometry, treatment of the geometry of the part is a key in process planning. To recognize the part section geometry, the section entity representation, the section coordinate-redius representation and the section primitive geometru were adopted. This system includes six major modules such as input module, forging design module, forming sequence design module, die design module, FEM verification module and output module which are used independently or in all. The sequence drawing wigh all dimensions, which includes the dimensional tolerances and the proper sequence of operations, can generate under the environment of AutoCAD. The acceptable forming sequences can be verified further, using the FE simulation.
A Basic Research on Estimation of Material Condition by Using Stress Dependency of Sound Speed
Kim, K.J. ; K.Y. Jhang ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 53~60
In the conventional linear elasticity, sound speed is determined by only elastic modulus and density of the medium. In actual, however, sound speed depends on the stress and this dependency becomes nonlinear as the stress increases. These phenomena can be introducing nonlinear elastic modulus. In this paper, relationships between nonlinear elastic modulus up to 4th order and the internal status of materials are discussed through computer simulations and experiments. For the measurement of sound speed, a new type of measurement system using ultrasonic wave is proposed on the basis of ultrasonic pulse echo method which has been generally used in nondestructive ultrasonic test equipment. In order to confirm the stress dependency of sound speed, several experiments are carried out for alumina specimen.
Machined Surface Plastic Strain in Orthogonal Cutting by Subsequent Recrystallizations Technique
Y. Iino ; Kim, T.Y. ; S.D. Mun ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 61~66
The subsequent recrystallizations technique, and experimental strain measurement method by use of recrystallization phenomena, has been successfully applied for the observation of machined surface plastic zones with equivalent plastic strain .epsilon. .geq. 0.5, 0.12 and 0.02 of type 304 stainless steel. The depth of the zone with .epsilon. .geq. 0.5 is very small, 10-15 .mu. m, while those with .epsilon. .geq. 0.12 are 100-200 .mu. m and 200-450 .mu. m, respectively. The depths increase with increasing depth of cut and with decreasing rake angle. The relation between the depth of the zones and the cutting paramenters is shown. The deformation state ahead of the quick-stop cut was also well visualized by the technique.
3-Dimensional Error Calibration of CMMs Using a Hole-Plate Artefaet
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 67~74
The Design of Fuzzy-Neural Controller for Velocity and Azimuth Control of a Mobile Robot
S.H. Han ; Lee, H.S. ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 75~86
In this paper, we propose a new fuzzy-neural network control scheme for the speed and azimuth control of a mobile robot. The proposed control scheme uses a gaussian function as a unit function in the fuzzy-neural network, and back propagation algorithm to train the fuzzy-neural network controller in the frame-work of the specialized learning architecture. It is proposed a learning controller consisting of two fuzzy-neural networks based on independent reasoning and a connection net woth fixed weights to simply the fuzzy-neural network. The effectiveness of the proposed controller is illustrated by performing the computer simulation for a circular trajectory tracking of a mobile robot driven by two independent wheels.
A Study about Dynamic Behavior of the Face Milling Cutter to Minimize Resultant Cutting Force
Kim, J.H. ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 87~96
On face milling operation a newly optimal tool, which can minimize the resultant cutting forces resulted from the cutting force model, was designed and manufactrued. Cutting experiments using the new and conventional tools were carried out and the cutting forces resulted from those tools were analyzed in time and frequency domains. The performance of the optimized cutter was tested through the dynamic cutting forces resulted form the newly designed tool are much reduced in comparision with those from the conventional tool. By reducing the dynamic cutting force fluctuations, machine tool vibrations can be reduced, and stable cutting operation can be carried out.
Study on Optimal Design of Fault-Tolerant Spatial Redundant Manipulators
Kim, W.K. ; Kim, D.K. ; B.J. Yi ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 97~108
Optimal design of fault-tolerant, spatial type redundant manipulators is treated in this paper. Design objective is to guarantte three degree-of -freedom translational motions in the task space, upon failure of one arbitrary joint of 4 degree-of-freedom manipulators. Noticing the nonfault-tolerant characteristics of current, wrist-type industrial manipulators, five different fault-tolerant spatial-type manipulators which have 4 degree-of-freedom structures with one joint redundancy are suggested. Faault-tolerant character-sitics of two redundant manipulators anr investigated based on the analysis of the self-motion and the null-space elements. Finally, in order to maximize the fault-tolerant capability, optimal design is performed for a spatial-type manipulator with respect to the global isotropic index, and the performance enhancement of the optimized case is shown by simulation.
Force/Moment Transmissionability Analysis of a Parallel Manipulator
B.J. Ahn ; K.S. Hong ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 109~121
This paper presents how the input forces along the prismatic joints of a parallel manipulator are transmitted to the upper platform. In order to consider force transmission and moment transmission seperately the Jacobian matrix for parallel manipulators is splitted into two parts. Magnitudes of input forces on the six actuators at a given manipulator configuration which generate maximum/minimum output force with no moment generated on the platform are obtained through the singular value decomposition of a matrix involving the Jacobian. Similarly the directions of the input forces to obtain only the rotation of the platform have been analyzed. Using the singular values a simple equation for the volume of ellipsoid which is a good tool for manipulability measure is provided. Obtained results could be useful in determinimg design parameters like radius of plaform, angles between joints, etc. Simulations are porvided.
Repetitive Control of Contact Force
D.Y. Jeon ; I.Y. Jong ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 122~128
In high speed and high precision assembly systems such as a surface mounting device and robotend effector, the contact force control is required. As the operation repeats, the repetitive control is applied to reduce the periodic contact force errors. Since high order unmodelled dynamics are easily excited in contact force control, a Q filter was introduced and its robust stability was analyzed. Simulation and Experimental results show the effectiveness of the algorithm.
Analysis of Gear Noise and Design for Gear Noise Reduction
K.Y. Yoon ; Park, W.J. ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 129~135
The area of gear vibration and noise, has recently been the focus of many studies. The proper kinematic and geometric design of gears, the mathematical modeling of gear system are essential for a good design. This work present a gear disign for reducing noise, and practical approaches used for machinery noise reduction slong with the summary of methods available for predicting gear noise in terms of the transmis- sion error, and show a comparative study with other methods. A new tooth profile modification is proposed for reducing vibration and noise of involute gears. The method is based on the use of cubic spline curves. The tooth profile is constrained to assume an involute shape during the loaded operation. Thus the new gear profile assures conjugate motion at all points along the line of action. The new profile is found to result in a more uniform static transmission error compared to not only standard involute profile but also modificated profile therby contributing to the improvement of vibration and noise characteristics of the gear.
A Study on the Characteristics of AE Signals of Tool Failure for Continuous and Interrupted Cutting under CNC Lathe
Kim, T.B. ; Kang, S.Y. ; Kim, W.I. ; Lee, Y.K. ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 136~142
Automatic monitoring of cutting process is one of the most important technology in machining. AE sensing technology has been applied to monitoring process and proved to be effective in detecting tool abnor- malities such as tool wear and fracture. In this experimental study. AE signals were detected from the tool holder for continuous and interrupted cutting, which obtained from changing workpice material configuration, under control of constant cutting speed from CNC lathe. From statistical and frequency analysis, the AE signals were analyzed to obtaining the characteristics of continuous and interrupted cutting conditions and tool failure. The Kurtosis values decreased but RMS voltages increased as the cutting speed increased, in both continuous and interrupted cutting. RMS voltage is suddenly increased but Kurtosis value is suddenly decreased when tool failure condition. Power spectrum density of AE signals when tool failure reaches extreme value around 0.065 cycles/ .mu. m.
A Method of Component-Machine Cell Formation for Design of Cellular Manufacturing Systems
K.K. Cho ; Lee, B.U. ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 143~151
The concept of cellular manufacturing is to decompose a manufacturing system into subsystems, which are easier to manage than the entire manufacturing system. The objective of cellular manufacturing is to group parts with similar processing requirements into part families and machines into cells which meet the processing needs of part families assigned to them. This paper presents a methodology for cell formation based on genetic algorithm which produces improved cell formation in terms of total moves, which is a weighted sum of both intercell moves and intracell moves. A sample problem is solved for two, three and four cells with an approach based on genetic algorithms.
A Study on the Development of CNC Lathe for Noncircular Cutting
K.S. Kim ; J.K. Kim ; S.P. Yang ; J.H. Kim ; D.Y. Lee ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 152~162
The purpose of this study is the development of a lathe which can cut any pistons of oval shape with high speed, accuracy and precision by CNC (Computer Numerical Control) method. Y axis which is the position determinating mechanism with high speed response was added to the CNC lathe and the ovality and profile was cut under the control of C-Y-Z axes at same time. In the case of ovality of .phi. 0.2mm, the productivity can be improved up to 2500rpm(Y axis:83Hz) by high speed cutting than modeling method. Since a personal computer is used, it is easy to change the shape of pistion and can be applied promptly to many types of piston shppe by only changing data files.
Determination of Optimal Build-up Direction for Stereolithographic Rapid Prototyping
J.H. Hur ; Lee, K.W. ;
Journal of the Korean Society for Precision Engineering, volume 13, issue 4, 1996, Pages 163~173
Stereolithography is a process used to rapidly produce polymer components directly form a computer representation of the part. There are several considerations to be made for the efficient use of the process. Especially, the build-up orientation of part critically affects the part accuracy, total build time and the volume of support structures. The purpose of tis study is to determine the optimal build-up part orientation for the SLA process with improving part accuracy, and minimizing total build time and the volume of support structures. The forst factor is related to the area of surfaces whioch have staircase protrusions after solidification, the second factor is related to the total number of layers, and the third factor is related to the area of the surfaces which need to be supported with support structures. An algorithm is developed to calculate the staircase area, quantifying the process errors by the volume of materials supposed to be removed or added to the part, and the optimal layer thickness for the SLA system which can handle the variable layer thickness. So the optima l part orientation is determined based on the user's selections of primary criter- ion and the optimal thickness of layers is calculated at any part orientations.