Go to the main menu
Skip to content
Go to bottom
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 12, Issue 12 - Dec 1995
Volume 12, Issue 11 - Nov 1995
Volume 12, Issue 10 - Oct 1995
Volume 12, Issue 9 - Sep 1995
Volume 12, Issue 8 - Aug 1995
Volume 12, Issue 7 - Jul 1995
Volume 12, Issue 6 - Jun 1995
Volume 12, Issue 5 - May 1995
Volume 12, Issue 4 - Apr 1995
Volume 12, Issue 3 - Mar 1995
Volume 12, Issue 2 - Feb 1995
Volume 12, Issue 1 - Jan 1995
Selecting the target year
Machine Tool Technology;The Present And The Future(6)
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 5~21
Experimental Identification of Rigid Body Properties by Direct System Identification Method
Jeong, W.B. ; Ryu, S.J. ; Koe, D.M. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 22~29
An experimental method to identify the rigid properties (mass, moment of inertia, center of mass) of mounted structures is presented. A direct system identification method is developed and applied to identify the mass, damping and stiffness martix directly from the translational response of vibration testing. Conventional method is sensitive to noise since it needs artificial rotational response of temporary center of mass which is made by the linear transformation of translational response. A presented method needs only the translational response, and it is robuster to noise than conventional method. Several experimental and numerical implementations show the presented method is effective.
A Study on the Experimental Analysis of the Automatic Fine Polishing System
Park, G.M. ; J.H. Jang ; C.S. Han ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 30~39
Now a days, securing skilled workers is very difficult due to the hardworking environment. This situation will be getting worse in the future and also that makes the dies/molds industries difficult. In this research, the automatic fone polishing system which can be directly attached to the spindle of CNC machine is proposed and analyzed. The system is also controlled by the NC progra data created by CAD/CAM system. The usefulness and effectiveness of the developed system are verified more detail through some comparisons between automatic and manual polishing experiments. The experiments show that the automatic polishing is a more useful and effective process than manual one. For the application, this system can be easily used for the polishing process in the area of any fine surface.
Evaluation System of Assemblability in Bolt Feature -Stability of Laying and Handlability of Parts-
H.S. Mok ; Kim, G.Y. ; Lee, J.C. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 40~51
The assemblability was determined by the structure of product and the relationship between composing parts and machining parts. In this paper, the bolt was divided into bolt-head, -shaft, -thread and -end. For the better assemblability in bolting process, the geometric and technological characteristics of bolts in terms of pre- and in-assembly process were analyzed. And this paper presents assemblability evaluation for bolt feature design alternatives. For this evaluation system, we considered systematically eight factors for assemblability, but introduced two factores for the stability of laying and for the handlability of parts. And AutoCAC system is interfaced with the evaluation system written in C-language.
The Measurment Method of Small Deformation by using Holographic Interferometry
Y.J. Kang ; S.J. Moon ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 52~58
Conventional measurement methods for non-destructive testing(NDT) in nuclear power plants and other industrial plants have been performed as the methods of contact with objects to be inspect, but those methods have been taken relatively much time to be inspected. Holographic interferometry which is a non-contact optical measurement method using a coherent light can overcome these demerit, and also has an advantage that the quantitative measurement of small deformation for large areas can be accomplished at a time with high precision. In this paper the comparisons of the experimental results form holographic interferometry with those from the finite element method(FEM) and the analytical solutions of the elastic equation are discussed.
Study on BLENDED CAM DESIGN
M.Y. Yang ; T.Y. Shon ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 59~65
The cam is used to a main component in a variety of automatic machines and instruments. To meet the demand of a complicated operation and of reducing weight for automatic machine, Curve Blending Technology, in which each of the basic curves suitable for individual interval is connected, is used for the cam design. In the curve blending, it is necessary to select appropriate elementary curve for each interval and to confirm the dynamic continuity at connecting points between adjoining elementary curves. This paper represented the elementary curve selection method to select an appropriate curve for each interval, and executed computation for the follower displacement and angular displacement of each interval. The paper made an analysis and examine closely for elementary curves to synthesizing curve blending, and it performed dynamic conditions clearly at every points on the cam motions. Therefore the curve blending technology presented by the paper turned into easier work.
Monitoring/Control System for Cylindrical Plunge Grinding
S.H. Kin ; B.C. Jung ; J.H. Ahn ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 66~73
This paper presents monitoring and control system to decrease non-production time such as air grinding and partial contact in cylindrical plunge grindings. The 4-stage model of the plunge grinding process is proposed according to the state of contact between grinding wheel and workpiece; air grinding, partial contact, entire contact and spark out. Experimentally it is seen that the AE sensor and ultrasonic sensor are very effective to detect the grinding states. Monitoring and control algorithm using recognized grinding process was introduced and a experiment were conducted to verify the developed system.
Evaluation of Grade of WA-Vitrified and Resinoid Bond Grinding Wheels by Acoustic Emission
I.K. Joung ; Y.H. Lim ; D.H. Kwon ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 74~85
The purpose of this paper is to evaluate the grade of WA vitrified and resinoid bond grinding wheels by the sue of AE measuring system. When the manufactured 48 kinds of specimens were scratched by the method of OKOSHI'S grade test, the relationship between the amount of bit scratch depth of grinding wheel specimens and the character- istics of AE signals, and the relationship of AE counts and grade were considered as fololws; (1) The higher the grades are AE cumlulative event counts N and AE event count rate n, the smaller the values tend to be. But A
is in reverse. (2) In the case of same grade, the smaller the grain size is, the higher the value of AE cumulative event counts N and A
is results of comparison and observation. The grinding wheel with lower elasticity and with higher percentage of pore detected higher value of AE cumula- tive event counts N than with higher elasticity and lower percentage of pore. But A
is in reverse. (3) AE cumulative event counts N and bit scratch depth h have normally one to one correspondence. (4) It can be expected that quantitative evaluations of grade by using AE have been carried out by the wave observation of AE signal in line with the relationship between load speed of bit and AE cumulative event counts N & AE event count rate n.' AE event count rate n.ate n.
A Bead Shape Classification Method using Neural Network in High Frequency Electric Resistance Welding
Ko, K.W. ; Kim, J.H. ; Kong, W.I. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 86~94
Bead shape in high frequency electric resistance (HER) pipe welding gives useful information on judging current welding conditon. In most welding process, heat input is controlled by skilled operators observing color and shape of bead. In this paper, a visual monitoring system is designed to observe bead shape in HERW pipe welding process by using structured light beam and a C.I.D(Charge injection device) camera. To avoid some difficul- ties arising in extracting stable features of stripe pattern and classifying the extracted features, Kohonen neural network is used to classify such bead shapes. The experimental results show accurate classification performance of the proposed method.
Adaptive Control by the Fusion of Genetic Algorithms and Fuzzy Inference on Micro Hole Drilling
Park, I.H. ; W.S. Chung ; H.J. Kweon ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 95~103
Recently the trends toward reduction in size of industrial products have increased the application of micro drilling. But micro drilling has still much difficulty so that the needs for active control which give adaptation to controller are expanding. In this paper initial cutting condition was determined for some sorkpieces by experiment and GA-based Fuzzy controller was devised by genetic algorithms and fuzzy inference. The fuzzy inference has been applied to the various prob- lems. However the determination of the membership function is one of the difficult problem. So we introduce a genetic algorithms and propose a self-tuning method of fuzzy membership function. Based on this intelligent control, automation of micro drilling was carried out like the cutting process of skilled machinist.
Application of Nonlinear Feedback Control to an Articulated Manipulator
Y.S. Baek ; C.I. Yang ; H.S. Aum ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 104~114
Mathematical models of industrial robots or manipulators are composed of highly nonlinear equations with nonlinear couplings between the variables of motions. These nonlin- earities were not considered important in the first stage that the working speed of the manipulator was not so fast, but the effect of nonlinear forces has become serious, as the working speed has been increased. So more improvement of performance cannot be expected by the control of manipulator using approximate linearization. As an approach for solving these problems, there is a method that eliminates nonlinear theory, which makes possible cecoupling of coupling terms and arbitrary arranging of poles is briefly introduced in this study. When the theory is applied to design the control law, its feasibility is examined whether the reasonable control results are obtained by simulating position, velocity, torque and tracing trajectory. The relations between the coefficients of the linearized differential equations and the maximum error and torque for the prescribed trajectory are also examined. Finally, the method for selecting the values for getting the most rapid and precise response within maximum torque of each drive is suggested in the choice of coefficients of characteristic equations which are obtained as a result of the control
Observation and Analysis of Break Out at the Exit Stage in Oblique Cutting
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 115~125
UBET Analysis and Model Test of the Forming Process of Magnetron Anode
Jo, K.H. ; Bae, W.B. ; Yang, D.Y. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 126~136
Copper magnetron anode of a microsave-over consists of an cylindrical outer-tube and various inner-vanes. The magnetron anode is produced by the complex processes; vane blanking, pipe cutting and silver-alloy brazing of vanes. Recently, the backward extrusion process for forming vanes has been developed to avoid the complex procedures. The developed process is analyzed by using upper-bound elemental technique (UBET). In the UBET analysis, the upper-bound load, the configuration and the vane-height of final extruded product are determined by minimizing the roral power consumption with repect to chosen parameters. To verify theoretical analysis, experiments have been carried out with pure plasticine billets at room temperature, using different web-thickness and number of vanes. The theoretical predictions both for forming load and vane-height are in reasonable agreement with the experimental results.
An efficient method for computation of unbalance responses of rotor-bearing systems
S.W. Hong ; Park, J.H. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 137~147
The unbalance response analysis is one of the essential area in the forced vibration analysis of rotor-bearing systems. Local bearing parameters in rotor-bearing systems are the major sources which give rise to a difficulty in unbalance response computation due to the complicated dynamic properties such as rotational speed dependency and anisotropy. In the present paper, an efficient method for unbalance responses is proposed so as to easily take into account bearing parameters in computation. An exact matrix condensation procedure is proposed which enables the present method to compute unbalance responses by dealing with condensed, small matrices. The proposed method causes no errors even though the computation procedure is based on the small matrices condensed from the full matrices. The present method is illustrated through a numerical example and compared with the conventional method.
A Study on the Applications of Finite Element Techniques to Chip Formation and Cutting Heat Generation Mechanism of Cutting Process
J. Hwang ; S. Namgung ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 148~155
The object of this study is to achieve a gteater understanding of meterial removal process and its mechanism. In this study, some applications of finite element techniques are applied to analyze the chip formation and cutting heat generation mechanism of metal cutting. To know the effect of cutting parameters, simulations employed some independent cutting variables change, such as constitutive deformation laws of workpiece and tool material, frictional coefficients and tool-chip contact interfaces, cutting speed, tool rake angles, depth of cut and this simulations also include large elastic-plastic defor- mation, adiabetic thermal analysis. Under a usual plane strain assumption, quasi-static, thermal-mechanical coupling analysis generate detailed informations about chip formation process and cutting heat generation mechanism Some cutting parameters are affected to cutting force, plastic deformation of chip, shear plane angle, chip thickness and tool-chip contact length and reaction force on tool, cutting temperature and thermal behavior. Several aspects of the metal cutting process predicted by the finite element analysis provide information about tool shape design and optimal cutting conditions.
Bin-Picking Method Using Laser
K.S. Joo ; M.H. Han ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 156~166
This paper presents a bin picking method using a slit beam laser in which a robot recognizes all of the unoccluded objects from the top of jumbled objects, and picks them up one by one. Once those unoccluded objects are removed, newly developed unoccluded objects underneath are recognized and the same process is continued until the bin gets empty. To recognize unoccluded objects, a new algotithm to link edges on slices which are generated by the orthogonally mounted laser on the xy table is proposed. The edges on slices are partitioned and classified using convex and concave function with a distance parameter. The edge types on the neighborhood slices are compared, then the hamming distances among identical kinds of edges are extracted as the features of fuzzy membership function. The sugeno fuzzy integration about features is used to determine linked edges. Finally, the pick-up sequence based on MaxMin theory is determined to cause minimal disturbance to the pile. This proposed method may provide a solution to the automation of part handling in manufacturing environments such as in punch press operation or part assembly.
Active Vibration Control of a Flexible Cantilever Beam Using SMA Actuators
Park, S.B. ; C.C. Cheong ; I.S. Hwang ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 9, 1995, Pages 167~174
This paper experimentally demonstrates the feasibility of using shape memory alloy(SMA) actuators in controlling structural vibrations of a flexible cantilevered beam. The dynamic characteristics of the SMA actuator are identified and integrated with the beam dynamics. Three types of control schemes; constant amplitude controller(CAC), proportional amplitude controller (PAC) and sliding mode controller(SMC) are designed. The CAC and PAC are determined on the basis of physical phenomenon of the SMA actuator, while teh SMC is formulated in a mathematical manner. The proposed controllers are implemented and evaluated at various operating condirions by investigating the control level of suppression in transient vibration.