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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 3, Issue 4 - Dec 1986
Volume 3, Issue 3 - Sep 1986
Volume 3, Issue 2 - Jun 1986
Volume 3, Issue 1 - Mar 1986
Selecting the target year
Technology Development Strategy of Machine
Lee, Gyeong-Hun ;
Journal of the Korean Society for Precision Engineering, volume 3, issue 1, 1986, Pages 9~12
MAP (Manufacturing Automation Protocol)
Lee, Bong-Jin ;
Journal of the Korean Society for Precision Engineering, volume 3, issue 1, 1986, Pages 13~19
An adaptive control algorithm for the speed control of hydraulic-servo system
Yun, Ji-Seop ; Jo, Hyeong-Seok ;
Journal of the Korean Society for Precision Engineering, volume 3, issue 1, 1986, Pages 29~39
An adaptive controller which is robust to the unknown load disturbance is developed for electro-hydraulic speed control systems. Since the load disturbance degrades the performance of the controller such as a steady state error and rise time in the conventional control system, appropriate adjustment of the controller is necessary in order to obtain the desired performances. The adaptation mechanism was designed to tune the feedforward gain, based upon minimization of ITAE (integral of time-multiplied absolute error) performance. The unknown load distrubance was identified by using an analog computer from the relationship between the velocity of the hydraulic motor and the load pressure. To evaluate the performance of the controller a series of simulations and experiments were conducted for various load conditions. Both results show that the proposed adaptive controller shows abetter performance than the conventional controller in terms of the steady state error and rise time.
A study on Crack Healing of Various Glassy Polymers (part I) -theoretical modeling-
Lee, Ouk-Sub ;
Journal of the Korean Society for Precision Engineering, volume 3, issue 1, 1986, Pages 40~49
Crack, craze and void are common defects which may be found in the bulk of polymeric materials such as either themoplastics or thermosets. The healing phenomena, autohesion, of these defects are known to be a intrinsic material property of various polymeric materials. However, only a few experimental and theoretical investigations on crack, void and craze healing phenomena for various polymeric materials have been reported up to date [1, 2, 3]. This may be partly due to the complications of healing processes and lacking of appropriate theoretical developments. Recently, some investigators have been urged to study the healing phenomena of various polymenic materials since the significance of the use of polymer based alloys or composites has been raised in terms of specific strength and energy saving. In the earlier published reports [1, 2, 3, 4], the crack and void healing velocity, healing toughness and some other healing mechanical and physical properties were measured experimentally and compared with predicted values by utilizing a simple model such as the reptation model under some resonable assumptions. It seems, however, that the general acceptance of the proposed modeling analyses is yet open question. The crack healing processes seem to be complicate and highly dependent on the state of virgin material in terms of mechanical and physical properties. Furthermore, it is also strongly dependent on the histories of crack, craze and void development including fracture suface morphology, the shape of void and the degree of disentanglement of fibril in the craze. The rate of crack healing may be a function of environmental factors such as healing temperature, time and pressure which gives different contact configurations between two separated surfaces. It seems to be reasonable to assume that the crack healing processes may be divided in several distinguished steps like stress relaxation with molecular chain arrangement, surface contact (wetting), inter- diffusion process and com;oete healing (to obtain the original strength). In this context, it is likely that we no longer have to accept the limitation of cumulative damage theories and fatigue life if it is probable to remove the defects such as crack, craze and void and to restore the original strength of polymers or polymer based compowites by suitable choice of healing histories and methods. In this paper, we wish to present a very simple and intuitive theoretical model for the prediction of healed fracture toughness of cracked or defective polymeric components. The central idea of this investigation, thus, may be the modeling of behavior of chain molecules under healing conditions including the effects of chain scission on the healing processes. The validity of this proposed model will be studied by making comparisons between theoretically predicted values and experimentally determined results in near future and will be reported elsewhere.
On the Synthesis of Robot Manipulator using Adaptive Control
Lee, Si-Bok ; Lee, Man-Hyung ; Park, Jong-Jin ;
Journal of the Korean Society for Precision Engineering, volume 3, issue 1, 1986, Pages 50~59
Adaptive Model Following Control (AMFC) technique is applied to develop a robot manipulator control system, which can deal successfully with the complex dvnamics of the manipulator. Main concerns of this study are put on the problem reducing the chatter amplitude of control signal yielded by the unit vector control law that was proposed  previously for AMFC of the manipulatro, and the effect- iveness of the algorithm when implemented practically. To see the effectiveness of modified method, computer simulations using new and old control law are carried out and compared, and the modified one id implemented in RHINO XR-II robot system recon- structed partially to enable torque control.
A study on measuring and evaluating in stylus type 3-D surface roughness.
Han, Eung-Kyo ; Kim, Hee-Seouk ;
Journal of the Korean Society for Precision Engineering, volume 3, issue 1, 1986, Pages 60~68
Measurement of surface roughness has been done by two dimensional method until now. In recent, three dimensuional method is introduced for the precise measurement of surface roughness. But the study about stylus type three dimensional measurement method is a little. Therefore, in this study, arbitrary machined surface is selected and same part is measured by two dimensional and three dimensional method. The result is that the ratio of tow dimensional to three dimensional value is 0.9-1.1 in Ra. But two dimensional measurement method is underestimated because the ratio is 0.5-0.9 in Rz, Rmax. And it is suitable that the number of measuring line is 100 and y pitch is 5 um by three dimensional surface roughness measuring method.
The Influence by Stylus Tip Radius and Measuring force on the Stylus Type Surface Roughness Tester
Kang, Myung-Soon ; Han, Eung-Kyo ; Kwon, Dong-Ho ; Cho, Nahm-Gyoo ;
Journal of the Korean Society for Precision Engineering, volume 3, issue 1, 1986, Pages 69~76
The measuring Method by stylus, which measures surface roughness, has been widely used since G. Schmaltz developed the first equipment of that type. Withe the resent development of the measuring method by stylus, surface foughness testing instruments of the very high magnification ratio, hundreds of thousands, are manu- factured. However, as the techniques of the high precision roughness measurement are being required, the response problems due to the tip shapes and the plastic deformations of measured surface of mild material are to be serious factors. In this study, diamond stylus of tip radius
were used under the measuring force of 0.01gf, 0.02gf, 0.07gf, 0.4gf and 1.6gf, and from the experimental data, maximum measured value devrements between
stylus are 22% and 31%, respectively when the measured value of
stylus goes to
c2.5mm. And it is shown that plastic deformations on the plastic deformations on the measured surface are proportional to W/R(W;measured force, R;stylus tip radius).
Design Alterntives for Robot-based Wire Harness Assembly Processes
Jo, Hyeong-Seok ; Gwon, Dae-Gap ;
Journal of the Korean Society for Precision Engineering, volume 3, issue 1, 1986, Pages 77~92
Wire harness assembly is one of the most labor intensive processes in manufa- tuing, but the process has not been fully automated yet. In this paper a variety of concepts for flexible automated assembly system are suggested to design a robot- based wire harness assembly cell. All concepts are featuring an automatic, fedkng of wires, terminating routing, inserting and bundling. Based upon possible assembly methods and procedures, six alternative systems are proposed and, finally, evaluated10 from the view point of system performance such as flexibility, reliability assembly time and equipment cost.