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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
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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(4)
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 5~18
Improvement of Accuracy in Moire-type Laser Encoder Using Four Point Method
B.W. Jeon ; Park, T.W. ; Lee, M.H. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 19~25
Presently, along with the advance of high-technology, the precise measurement of linear displacement has become a staple requirement, and consequently the high resolution with submicron order has also been required in precise positioning and carriaging. In this paper, we advance a propose on a new type of laser encoder based on the principle of phase analysis of the moire fringes from superimposed two gratings. The phase angle as an information of displacement can be accurately calculated by detecting the change in brighness at four points of the fringes. The actual application of four point method to the moire fringes is performed thru microcomputer for general purpose, and the measuring procedure is also studied in this research. As an experimental result, in the case of using 20 .mu. m-pitch gratings, it is validated that this method has the resolution of 0.01 .mu. m and the accuracy of .+-. 0.15 .mu. m over the setting range of 100mm.
Design and Performance Evaluation of Micro Stepping Actuator with a Variable Step Size
Lim, Y.M. ; Kim, S.H. ; Kwak, Y.K. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 26~31
A new actuating mechanism suitable for a micro positioning device is developed using piezo-electric elements. The actuator can make a step movement of 0.5 .mu. m up to 3.5 .mu. m. The step size can be adjusted on demand. By repeating this step action, long distance movement is achieved. Precise positioning can be obtained by combining the coarse motion with the maximum step size and fine motion. Two types of fine motion have been proposed for a driving method. Firstly, feedback control bases on PID is applied. The experimental results for the two method are presented.
Neural network based tool path planning for complex pocket machining
Y.S. Shin ; S.H. Suh ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 32~45
In this paper, we present a new method to tool path planning problem for rough cut of pocket milling operations. The key idea is to formulate the tool path problem into a TSP (Travelling Salesman Problem) so that the powerful neural network approach can be effectively applied. Specifically, our method is composed of three procedures: a) discretization of the pocket area into a finite number of tool points, b) neural network approach (called SOM-Self Organizing Map) for path finding, and c) postprocessing for path smoothing and feedrate adjustment. By the neural network procedure, an efficient tool path (in the sense of path length and tool retraction) can be robustly obtained for any arbitrary shaped pockets with many islands. In the postprocessing, a) the detailed shape of the path is fine tuned by eliminating sharp corners of the path segments, and b) any cross-overs between the path segments and islands. With the determined tool path, the feedrate adjustment is finally performed for legitimate motion without requiring excessive cutting forces. The validity and powerfulness of the algorithm is demonstrated through various computer simulations and real machining.
Development of Radiation Thermometer using InSb Photo-detector
B.O. Hwang ; Lee, W.S. ; K.Y. Jhang ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 46~52
This paper proposes methodologies for the development of radiation thermometer using InSb photo-detector of which spectral sensitivity is excellent over the wave length range of 2 .mu. m .approx. 5 .mu. m. The proposed radiation thermometer has broad measurement range from normal to high, up to more than 1000 .deg. C, with high accuracy, and can measure temperature on the material surface or heat emission noncontactely with high speed. Optical system was consisted of two convex lens with foruslength of 15.2mm for infrared lay focusing, Ge filter to cut the short wave length components and sapphire filter to cut the long wave length components. The cold shielded was installed in the whole surface of the light-absorbing element to remove the error- mometer, calibration using black body furnace which has temperature range of 90 .deg. C .approx. 1100 .deg. C was carried out, and temperature calaibration curve was obtained by exponential function curvefitting. The result shows maximum error less than 0.24%(640K .+-. 1.6K) over the measurement range of 90 .deg. C .approx. 700 .deg. C, and from this result the usefulness of the developed thermometer has been confirmed.
Optical Analysis in Particle Image Processing of Rotating Flow
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 53~65
Development of Rating Systems for Power Transmission Bevel Gears
T.H. Chong ; J.J. Chi ; J.H. Byun ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 66~73
Rating systems of bevel gears(straight, spiral, and zerol bevel gears) which are commonly used as power transmission devices for non-papallel axes are developed on the personal computer, which analyze and/or evaluate the gear design and the service performance at the point of view of strength and durability. The typical considerations of the ratings are the bending strength, the surface durability, and the scoring resistance. The ratings are carried out using the reliable standards of AGMA & Gleason Works. Therefore, the system is built so that the variables or factors considered differently in those standards and the strength, dura- bility, and scoring partially in Gleason are appraised seperately by each method, and a series of the estimation processes is integrated into the system so as to compare each result. The developed rating systems can be used in the initial stage of gear design process, and also a better design can be performed by the evaluation of the initial design at the view point of gear strength and durability. Additionally, it is useful for the trouble-shooting of bevel gear system and to the purpose of introducing the methods for maintaining design strength in service, with appraising the gear strength after design or with appraising the influencing factor as a whole. Therefore, this rating systems can help the aim of design automation of bevel gears.
Composite Control of Active Suspension System
K.B. Han ; Lee, S.B. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 74~81
In this paper, a composite controller cosisted of bandpass feedback controller and LQG/LTR controller is applied to a quarter-car model moving on a randomly profiled road. The LQG/LTR controller is used to achieve a design transfer toop. A bandpass feedback controller is adopted to eliminate the response due to the disturbance, which generally can not be measured, confined within an interested frequence range. The random road profile considered as colored noise is shaped from white noise by use of shaping filter. The performance of the composite control system is compared with that of an LQG/LTR control system.
A Study on the Optimal Combination of Leaf and Air Spring for the Suspension
Park, S.J. ; H.H. Kwon ; Park, J.C. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 82~91
Many kind of springs are used in the suspension of automotive vehicles and among these the leaf spring and the air spring are included. These two springs have not been generally used together in one suspension, but recently the automotive models which use these two springs together increase. This reason is due to the merit of the combination of two type springs. The merits are two. One is the character of air spring, that is, the natural frequen- cy of system is constant in spite of variable weight. The other is the character of leaf spring, that is, the suspension mechanism is simple. The combination spring is used in medium size and special purpose bus. In this paper, we formulate the condition which the leaf spring must satisfy to be optimal design in the combination spring. And experiment is performed to prove the theory. The results are that the combination spring is better than leaf spring in the ride, and that the purposed theory is good for the combination spring design.
Design and Performance Evaluation of the Precision Pressure Control System for the High Vacuum Transport Module
Jang, W.I. ; Jang, K.H. ; Lee, J.H. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 92~98
In the cluster tool, it is necessary to precisely control the vacuum pressure for the wafer transportation between transport module and cassette or process modules with the range of 1*10
torr. So we have designed the pressure control system for the transport module of the cluster tool and have evaluated its performance. Digital PID is utilized with the weighted sum of both three previous errors and one current error. The feedback signal is put into the nitrogen mass flow controller using the transport module controller. This pressure control system can prevent the transport module from the particle generation and backstreaming of hazardous process gases of the process chamber.
An efficient method for computation of receptances of structural systems with sparse, non-proportional damping matrix
Park, J.H. ; S.W. Hong ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 99~106
Frequency response functions are of great use in dynamic analysis of structural systems. The present paper proposes an efficient method for computation of the frequency rewponse functions of linear structural dynamic models with a sparse, non-proportional damping matrix. An exact condensation procedure is proposed which enables the present method to condense the matrices without resulting in any errors. Also, an iterative scheme is proposed to be able to avoid matrix inversion in computing frequency response matrix. The proposed method is illustrated through a numerical example.
Dynamic Analysis of Spindle System with Magnetic Coupling(ll)
Kim, S.G. ; Lee, J.M. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 107~113
Using the mathematical model of the torsional vibration in spindle system with magnetic coupling, which was proposed in the paper of dynamic analysis of spindle system with magnetic coupling(l), we derive the equations of the motion and the form of the derived equations represents Duffing equation. Numerical analyses are executed in many conditions, namely the various types in magnetic coupling, changes of the gap between driver and follower. To verify the results of the therorectical analyses, a precision dynamic drive system is manufactured and methods of the test to measure the torsional vibration of the spindle system with magnetic coupling are presented ad thests in various conditions are carried out.
Digital Preview and Noninteracting Control of Tandem Cold Mills
Kim, J.S. ; Kim, S.S. ; Lee, G.T. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 114~122
A digital preview controller is designed for tandem cold mills to achieve a more improvement of the thickness accuracy. Simultaneously a blocked noninteracting controller is synthesized for rejecting the interactive effects among adjacent stands and for controlling independently each roll stand of tandem cold mills. The performance effects and characteristics of the suggested roll contol system are discussed in the practical viewpoint. The simulaltion results show that the thickness accuracy of tandem cold mills can be largely improved by the blocked noninteracting and digital preview controller.
Performance Investigation of a Brake System Featuring Electro-Rheological Fluids
Kim, G.W. ; Park, W.C. ; Cheong, C.C. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 123~130
This study presents model synthesis and performance investigation of a new brake system using electro-rheological(ER) fluids. Field-dependent Bingham properties characterized by non-zero yield stresses of the ER fluids are experimentally distilled. These properties are then incorporated with the governing equation of the proposed brake system which features design simplicity, fast response and salient controllability. After analyzing system performance with respect to design parameters such as electrode gap and length, an appropriate size of the brake is designed and fabricated. Both simulation and experimental works are undertaken in order to determine the feasibility and efficiency of the proposed brake system. The system performances are justified by evaluating field-dependent braking torques as well as braking times.
Performance Analysis of the Vehicle With Hydromechanical Transmission
C.S. Song ; S.I. Kang ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 131~137
The performance analysis is applied to the transmission of the tracked vehicle, comparing simulation results with vehicle test. The calculation method of hydrostatic pump/motor performance and power circulation is used for hydromechanical transmission simulation. And various shifting characteristics is analyzed by studying power flow at each range.
A Study on PWM Control of Hydraulic Cylinder Using High Speed Solenoid Valve
Park, S.H. ; Lee, J.K. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 138~147
The conventional PWM method, which was used in controlling the on-off valve, such as high-speed solenoid valve, was modulating the width of the pulse applied to the valve, by selecting arbitrary sampling time and modulating the duty-ratio in proportion to the error. However, in this method, a selection of long sampling time was inevitable and it was unable to get a high accuracy and a quick response. This study is for designing an appropriate controller for high-speed solenoid valve by proposing an improved duty-ratio modulation method using the Saw-toothed Carrier Wave which enables a short sampling time selection, high accuracy of control, and a quick response. Test which was carried out in the laboratory shows that transient and steady state response could be improved by PID controller.
A Study on Speed Control of Hydrostatic Transmission Using High Speed Solenoid Valve
Park, S.H. ; Lee, J.K. ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 148~157
This study deals with controlling the speed of Hydrostatic Transmission (HST) system throuth the control of pumping stroke of positive displacement pump using high-speed solenoid valve controlled by digital closed loop PWM method. The method which was done in this study is as follows: First, we modified original positive displacement pump and designed pumping stroke control system of HST by using the high-speed solenoid valve. Second, after experimenting static and dynamic characteristics on each signal flow, we identified system parameter of approximated model. Finally, to control the speed of HST, we controlled the angle of the swash plate of positive displacement pump by controlling the pressure in the control cylinder chamber. Test which was carried out in the laboratory shows that transient and steady state response could be improved by PID controller.
Selection on Optimum Grinding Wheel Based on the Qualitative Knowledge and Fuzzy Multi-decision Making
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 158~168
A Structural Modification for the Precise Servo Control of the Head Position in Computer Hard Disk Drive
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 169~177
Temperature Distribution of Tungsten Carbide Alloy Steel(WC-Co) for Surface Grinding
J.W. Nam ; Kim, W.I. ; S.J. Heo ;
Journal of the Korean Society for Precision Engineering, volume 12, issue 7, 1995, Pages 178~188
A study on the temperature distribution of tungsten carbide alloy steel(WC-Co) in surface grinding was conducted to improve the surface finish and to find optimum grinding conditions which would lead to efficient grinding operation by theoretical finite element method analysis and experimental test of workpiece under various conditions. Based on the comparixion of test results and FEM analysis data, it is concluded that the FEM computer simulation of heat transfer is useful in predicting the temperature distribution of test material that the increase of temperature is more infuleneced by the grinding depth than the grinding speed. And that the grinding energy flux of dey grinding is 4 to 6 time greater than wet grinding regardless of grinding speed and finally that the heat transfer does not take place in depth deeper than 3mm from the grinding surface.