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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 9, Issue 4 - Dec 1992
Volume 9, Issue 3 - Sep 1992
Volume 9, Issue 2 - Jun 1992
Volume 9, Issue 1 - Mar 1992
Selecting the target year
A Robust Tracking Control for Robotic Manipulators Using Sliding Modes
Choi, Seung-Bok ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 18~28
Development of Non-contact Torque Sensor
Son, Dae-Rak ; Im, Sun-Jae ; Kim, Chang-Seok ; Nam, Gung-Seok ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 29~33
A non-contact torque sensor was developed using amorphous alloy. The change of maixmum magnetic induction of C0-based amorphous alloy under the tensile and compressive stress was proportional to applied torque. For the construction of the torque sensor, a glass fiber reinforced-epoxy rod was used as shaft. The amorphous strips were attached on the epoxy shaft in the direction of
. The magnetizing coil and 2 sensing coil was installed. The static and dynamic test was carried out. The linearity and sensor hysteresis of the torque sensor was less than 1%.
Communication Software Development for a Workstation Controller in a CIM System
Do, Sung-Hee ; Park, Gyung-Jin ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 34~43
Computer Intergrated Manufacturing (CIM) is an emerging technology which aims at the total automation of a manufacturing system. Despite the extensive research on CIM in this decade, total automation seems to be far from reality for many reasons. In this study, the problems of implementing a CIM system are analyzed and a solution method is suggested. A set of software has been developed and tested for a workstation cotroller which controls closely integrated equipment in the low level of a flexible manufacturing system. The functions of the programs are communications between machines and computers and control of workstation scheduling. The software group is developed on IBM OS/2 operating system with 'c' language to enhance the portability. The usage of the software is presented to users through the Presentation Manager which is menu handler of OS/2 system. Although the software is developed for limited machine equipment, the scheme can be adopted to various machines due to the generality.
Equi-Value Line Program Development for 3-Dimensional Finite Element Models using Personal Computer
Lee, Seok-Soon ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 44~52
A post-processor is developed to be effectively usable in the personal computer. 3-dimensional controur lines are shown on the surface of the finite element model and also on the 3-dimensional cutting plane, using the function linearly interpolated onto the triangular elements which are constructed on the surface or sectional polygons. And these polygons are originated from the finite element model, 3-dimensional model is projected on the plane with hidden line removal by comparision technique. The graphic data file is used to increase the protability of the program. It is easy to use in the other computer system if the graphic routine adopted that computer system is developed. The developed program has wide applications in 3-dimensional finite element analysis.
Dynamic Performance Analysis for Secondary Suspension of Maglev Control Systems with a Combined Lift and Guidance
Kim, Jong-Shik ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 53~65
For improving the performance of maglev systems with a combined lift and guidance, it is suggested that the multivariable control systems and a secondary suspension should be added. The former is required to reject both track irregularities in vertical disturbances and wind gusts in lateral disturbances, and the latter to guarantee passengers against an unsatisfied criteria in ride quality. In this paper, bond graph model for the study of nonlinear dynamics of maglev systems with a combined lift and guidance is presented briefly. And, the secondary suspension is analyzed to understand the role of stiffness and damping factors in passive devices. Finally, LQG/LTR mulitivariable control systems are designed for the overall maglev systems with and without secondary suspension, and then the system performances in these two cases are evaluated.
A Study on Electromagnetic Joining of Aluminum Tubes to Polyurethane Cores
Kim, Nam-Hwan ; Son, Hui-Sik ; Hwang, Un-Seok ; Lee, Jong-Su ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 66~74
The joining processes of aluminum alloy tubes and polyurethane cores by electromagnetic impulsive compression are studied. The influences of various geometrical factors (the length of joined part, the thickness of tube, and the clearance between tube and core) and the process factors(the discharged energy and the number of discharge)are examined experimentally and discussed. And the magnetic pressure in metal/polymer joining is calculated and is compared to the pressure in metal/metal joining. The following results are obtained: (1) The joining strength is dependent upon the residual radial strain of the polyurethane cores. (2) The joining strength increases as discharged energy and the number of discharge increase, but decreases as the clearance, thickness and joining length of tube increases. (3) In the case of metal/polymer joining energy loss is increased and the value of magnetic pressure is less than that in the case of metal/metal joining.
An Experimental Study on the Characteristics of Impact Vibration Absorber with Free Mass
Yang, Bo-Suk ; Kim, Jong-Wan ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 75~81
In this paper, an impact vibration absorber that reduces the high vibration amplitude of a vibrating system is studied. This absorber consists of a free mass allowed to impact on to the secondary leaf spring so that the vibration energy is dissipated by converaion into noise and heat. The experimental parameters are weight of the free mass and impat clearance. According to the measured results, the high vibration in resonance region is reduced more effectively by the impact clearance ratio than by the mass ratio.
A Study on the Development of Measurement Setup for Crater Wear by Diffraction Grating in Turning
Kim, Yeong-Il ; Kim, Se-Jin ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 82~95
There is the high interest for sensing of tool wear with the aim of controlling machine tools productivity from the point of view of qualitity. Difficulties in this measurement are also known. This study is on the development of measurement setup for crater wear by CCD image inturning. In this study, the crater wear measurement system consists of the He-Ne gas laser, diffraction grating. CCD camera, noise filter, slit, microcomputer, diverging lens, converging lens and so on. He-Ne laser beam passes through a diverging lens and a diffraction grating is positioned properly. A converging lens focuses so that the interference fringes can be obtained on the crater wear. Performance test revealed that the developed image technique provides precise, absolute tool-wear quantification and reduces human measurement errors. The results obtained are as follows 1. The digitizing of one image requires less than 2ses. 2. It can give detailed information on crater wear with limited times and errors 3. All parameters required by specification are easily obtained for several points of the cutting edge.
A Study on the Construction of CAD/CAM system ; for Machining of Sculptured Surface of Die
Koo, Young-Hae ; Lee, Dong-Ju ; Namgung, Suk ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 96~105
A study on the construction of a CAD/CAM system operated by 16 Bit PC basic language, for machining sculptured surface of die, was carried out. The system consists of 2 steps i.e., process for geometric modelling by wire frame and process for machining data generation. Geometric modelling for sculptured surface is made by the point data fitting, parallel sweeping, normal sweeping and linear connection of cross section curve. Machining data are gained by cutter off-set of geometric model data and machining carried out by DNC. This system is to be proved enough for rough cutting by actual machining experiment. But, for becoming a high level system, another method of cutter off-set has to be regarded and system must be reconstructed by another program language.
A Study on Physically small Surface Fatigue Crack Growth Behavior in 7075-T651 Aluminum Alloy
Sin, Yong-Seung ; Seo, Seong-Won ; Yu, Heon-Il ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 106~117
In this study, the propagation behaviour and the closure phenomena of physically small surface cracks were investigated by the techinque of the Kikukawa-unloading elastic compliance method using a back face strain gage. The surface cracks initiated and propagated from notched specimens under constant amplitude bending load. The crack shape (aspect ratio) with approximately semi-circular at the early stage was changed to semi-elliptical as the cracks grew larger. The crack depth (a) could be expressed uniquenly by the crack length (c). The dependence of the crack propagation rate on the stress ratio R was strongly related in the lower
range. The deceleration of the surface crack propagation rate was prominent in lower R during the crack length was small. When the propagation rate was rearranged with the effective stress intensity factor range
the dependence of the crack propagation rate on the stress ratio R was found to be diminshed. These were caused by the crack closure phenomena that was most prominent at the lower propagation rate. The mechanism of crack closure phenomena was dominated by the plasticity-induced mechanism.
Joining of Thermoplastics by the Ultrasonic Welding
Park, Joon-Boo ; Lee, Chul-Ku ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 118~125
Joining of thermoplastics is an area of growing importance in the automotive, aerospace, electronics medical and other domestic appliance industries. While adhesive Bonding or mechanical fastening could be used to join thermoplastics, welding is very effective because of its speed and low cost. This study investgated the ultrasonic joining of thermoplastics. Four kinds of thermoplastics such as Acrylonitrile Butadiene Styrene, Polystyrene, Polyethylene and Polypropylene were used, ultilizing all possible joining combinations. In each combination of thermoplastics, the weldability of the joint was evaluated as a function of weld time, amplitude of vibration and pressure. It was generally found that joining of amorphous thermoplastics with semicrystalline thermopastics resulted in poor joints due to its different crystalline structure. Joining of the amorphous thermoplastics together and joining of the semicrystalline thermoplastics together produced the best joints owing to its same crystalline structure.
A Study Compensation Method for Dynamic Characteristics in Electro-Hydraulic Servosystem Equipping Load Pressure Feedback Compensator
Kim, Jong-Kyum ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 126~136
In this paper, a simple structured feedback compensation scheme for a electro-hydraulic servo system to keep the response characteristics unchanged regardless of the load variation is proposed. In electro-hydraulic servo system, servovalve is most important control element. But the relation between input corrent and output flowrate of the servovalve has properties as follows; firstly, in spite of constant input current, output flowrate decreases as load pressure increases, secondly, according to frequency response of typical servovalve, the characteristics of gain and phase shift is something like 2'nd order system. Load pressure feedback compensation method has been applied to eliminate the first influence, the second influence has been improved by phase lead compensation method. As a result of above compensation methods, regardless of variation load condition, spring and inertia load, the compensation scheme has been verified to be effective within the range of frequency less than 25Hz by static response and dynamic response in time domain and frequency domain through experiments.
Singularty Control of Robot Wrist Joints using Euler Parameters
Jeon, Ui-Sik ; Park, Su-Heung ;
Journal of the Korean Society for Precision Engineering, volume 9, issue 1, 1992, Pages 137~145
Considering the singularity of robot, singularity avoidance control of robot is very important. Because it is very difficult structurally to exclude the wrist singularity. Then new control policy is needed to overcome wrist singularity. In this paper, the singularity states of robot wrist was analyzed and control algorithms for 3 and 4 axes robot wrist were proposed. Application results of the proposed control algorithms to the path including singularity showed us their usefulness and validity.