• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2004.05a
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• pp.154-158
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• 2004

Power inductor is usually used in the field of the power circuit of a cellular phone, TFT LCD module etc.. This paper presents the development process of Power Inductor Full Automation Winding/Welding System for TFT LCD. This process, the process algorithm, high precision welding current control, design of welding head, high speed, high precision feeding mechanism, and user interface process control program technologies are included.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.05a
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• pp.34-39
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• 2003

Seam seal welding on the semi-conductor package is a process for sealing the packages of semiconductors, crystal parts, saw filters, oscillators with lid plate by seam welding. This paper present the development process of automatic seam seal welding system. In this process, the process algorithm, high precision welding current control, design of welding head, high speed and high precision feeding mechanism, user interface process control program technologies are included.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.84-91
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• 2004

A CCD camera with a laser stripe was applied to realize the automatic weld seam tracking in GMAW. It takes relatively long time to process image on-line control using the basic Hough transformation, but it has a tendency of robustness over the noises such as spatter and arc tight. For this reason, it was complemented with adaptive Hough transformation to have an on-line processing ability for scanning specific weld points. The adaptive Hough transformation was used to extract laser stripes and to obtain specific weld points. The 3-dimensional information obtained from the vision system made it possible to generate the weld torch path and to obtain the information such as width and depth of weld line. In this study, a neural network based on the generalized delta rule algorithm was adapted for the process control of GMA, such as welding speed, arc voltage and wire feeding speed.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.1
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• pp.31-35
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• 2005

Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or reduced. In order to reduce motor ripple, this research adapted the feedforward compensation method and neural network control. Experiments carried out with the linear motor test setup show that these control methods are effective in reducing motor ripple.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.358-362
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• 2004

Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or reduced. In order to reduce motor ripple, this research adapted the feedforward compensation method and neural network control. Experiments carried out with the linear motor test setup show that these control methods are effective in reducing motor ripple.

• Journal of Welding and Joining
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• v.31 no.1
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• pp.26-32
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• 2013

Recently, welding technology of nonferrous metals which were difficult to implement by arc welder has become available through digitalization of arc welding machine. Among them, the welding quality improvement of aluminum welding is very noticeable. These results increase the arc stability by controlling arc current and voltage waveform precisely, and control wire feed speed by synchronizing with arc current which the feed rate of filler wire is controlled by a precise motor control of servomotor and not by a simple constant speed feeding. Not only through the hardware digitalization of arc welding machine but also through advance of software of arc welding, it became possible to implement a certain level of welding quality by a simple operation. These led to CMT welding process implementation which requires low heat input than current arc welding and highly increased the applicability of the aluminum welding.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.792-795
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• 1996

In TIG welding of pipe, back bead size monitoring is important for weld quality assurance. Many researches have been performed on estimation of the back bead size by heat conduction analysis. However numerical conduction model based on many uncertain thermal parameters causes remarkable errors and thermomechanical phenomena in molten pool can not be considered. In this paper, filler wire feeding force in addition to weld current, wire feedrate, torch travel speed and orbital position angle is monitored to estimate back bead size in orbital TIG welding. Monitored welding process variables are fed into an artificial neural network estimator which has been trained with the monitored process variables (input patterns) and actual back bead size (output patterns). Experimental verification of the proposed estimation method was performed. The predicted results are in a good agreement with the actual back bead shape. The results are quite promising in that estimation of invisible back bead shape can be achieved by analyzing the welding parameters without any conventional NDT of welds.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.358-363
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• 1987

It is widely noted that pressure feedback systems have been devised to damp the fluid resonance effectively in precision speed control-for large inertia system. A compensation technique preserving the natural output disturbance discrimination characteristics at lower frequencies is proposed The load pressure across positive displacement acceleration. The technique involves feeding back load differential pressure, sensed by pressure transducers, though a simple analog compensatory circuit (high pass filter). The effectiveness of the damping is determined by the filter time donstant and loop gain. Nonlinear total hydraulic simulation results verify the possibility of linear model predictions of extending the closed loop bandwidth beyond the uncompensated frequency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.558-561
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• 2002

A CCD camera with a laser strip was applied to realize the automation of welding Process in GMAW. It takes relatively long time to process image on-line control using the basic Hough transformation, but it has a tendency of robustness over the noise such spatter and arc light. The adaptive Hough transformation was used to extract the laser stripe and to obtain specific weld points In this study, a neural network based on the generalized delta rule algorithm was adapted for the process control of GMA, such as welding speed, arc voltage and wire feeding speed.

• Journal of Power Electronics
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• v.10 no.6
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• pp.724-732
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• 2010

This paper presents an effective rotor current controller for variable-speed stand-alone doubly fed induction generator (DFIG) systems feeding an unbalanced three-phase load. The proposed current controller is developed based on proportional plus two resonant regulators, which are tuned at the positive and negative slip frequencies and implemented in the rotor reference frame without decomposing the positive and negative sequence components of the measured rotor current. In addition, the behavior of the proposed controller is examined in terms of control performance and stability with respect to rotor speed variations, i.e., slip frequency variations. Simulations and experimental results are shown to validate the robustness and effectiveness of the proposed control method.