• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.3
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• pp.33-39
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• 1994

The purpose of this research is to examine precise linear motion and rotary motion. A six-degrees-of-freedom fine motion mechanism is introduced to drive an object precisely in directions of X, Y and Z-axes and around them : three rectangular linear motion and rotary ones. An experimental mechanism is introduced in which a $70$\times$70$\times$70$\times$(${mm}^3$) cube object is driven by six PZT actuator. The study is to establish the six-degrees-of-freedom fine motion mechanism of linear motion and rotary motion using PZT actuator.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1596-1603
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• 2018

This paper presents the new design and validation process of the linear transverse flux machine of the stelzer machine for hybrid vehicle application. A linear transverse flux machine is a novel electric machine that has higher force density and power than conventional electric machine. The process concentrates on 2-dimensional and 3-dimensional analysis using equivalent magnetic circuit method considering leakage elements and it is verified by finite element analysis. Besides the force characteristics of all axis of each direction are analyzed. The study is considered by dividing the transverse flux electric excited type and the transverse flux permanent magnet excited type. Additionally three-dimensional analysis in this machine is accomplished due to asymmetric structure with another three axes. Finally, it suggests the new design and validation process of linear transverse flux machine for stelzer machine.

• Journal of the Korean Society for Precision Engineering
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• v.4 no.4
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• pp.25-35
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• 1987

This paper deals with the design of the digital controller for DC servo motor, and it is implemented for the cartesian coordinate 4 axes manipulator. A design method of the controller is adopted an algorithm using the digital position locked loop(DPLL) method and the linear PID control for the smooth motion. To simplify the hardware configuration of control system, 8279 keyboard/display controller, Z-80 CTC counter and 8255 PPI are used. Therefore the design method to control each motor as real-time is presented. To show effectiveness of the design, the PWM circuit and frequency/voltage converter are applied for the velocity control of robot system. When the proposed controller is applied to the 4-axes manipulator, it reveals that the error probabilities of X, Y and Z axis as 0.033%, 0.023% and 0.028% respectively.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.1
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• pp.51-57
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• 2014

This paper presents a synchronizing adaptive feedforward control for clamping servomechanism of injection molding machines. Based on MBS, virtual design model has been developed for a direct forcing clamping mechanism. A synchronizing controller is designed and combined with adaptive feedforward control to accommodate mismatches between the real plant and the linear plant model used. From tracking control simulations, it is shown that significant reduction in position tracking error is achieved through the use of proposed control scheme.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.2 s.245
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• pp.105-111
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• 2006

This paper describes a Neural Network based PID control scheme for pneumatic NC axes. Pneumatic systems have inherent nonlinearities such as compressibility of air and nonlinear frictions present in cylinder. The conventional PID controller is limited in some applications where the affection of nonlinear factor is dominant. A self-excited oscillation method is applied to derive the dynamic design parameters of linear model. The gains of PID controller are determined using a self tuning scheme. The experiments of a trajectory tracking control using the proposed control scheme are performed and a significant reduction in tracking error is achieved by comparing with those of a PID control.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.971-974
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• 1988

In this study, we designed a model of NC controller with IBM-PC as a host CPU and intelligent servo controller for 2 axes that can be expaned to 4 axes. OS software was developed with C language at the base of mode selection technic for 9 NC operating modes. Servo controller design was based on the application of interpolator IC(3701) and position controller IC(3702) that permits low cost and high performance. For connection of two systems, parallel I/O communication was implemented. Finally, auto interpolation program test was executed for linear and circular paths resulting 1 LSB accuracy.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.328-330
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• 2007

This paper deals with the estimation method on the initial pole position of a z-axis permanent magnet linear synchronous motor(PMLSM) without magnetic pole sensors such as Hall sensors. The proposed method takes account of the z-axis conditions such as the gravitational force and also the load conditions. The algorithm consists of two steps. The first step is to estimate the initial q-axis approximately by monitoring the movements at predefined different test q-axes. The second step is to estimate the real q-axis as accurately as possible based on the results at three different test q-axes. Experimental results on the z-axis PMLSM show good estimation characteristics of the proposed method.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.596-599
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• 2003

In this paper, we designed the digital pulse motor control chip including a circular interpolation function. The proposed algorithm in this paper is a nonparametric cure generation algorithm (Jordan's algorith) and a very simple algorithm. So the design for this algorithm used a small number of gates. Also an average error is fairly low. The max output speed is 4Mpps(Pulse per second), the max input frequency is 16MHz and the chip is useful for the stepping and servo motors. The software contains one or two, and many axes linear interpolation algorithm and two axes circular interpolation algorithm.

• Journal of Drive and Control
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• v.11 no.2
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• pp.9-15
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• 2014

This paper deals with the issue of force synchronizing control for the clamping servomechanism of injection molding machines. Prior to the controller design, a virtual design model has been developed for the clamping mechanism with hydraulic systems. Then, a synchronizing controller is designed and combined with an adaptive feedforward control in order to accommodate the mismatches between the real plant and the linear model plant used. As a disturbance, the leakage due to the ring gap with relative motion in the cylinder has been introduced. From the robust force tracking simulations, it is shown that a significant reduction in the force synchronizing error is achieved through the use of a proposed control scheme.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.4
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• pp.13-21
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• 1992

Standards concerning the determination of positioning accuracy and repeatability of numerically controlled(NC) machine tools have been published relentlessly over the last 20 years. Since the publication in 1988 of the International Standard 230-2 there has been a pronounced move, both at national and international standards level, to embrace further test procedures for a complete machine tool performance assessment. For example, measurements of angular (pitch, roll, and yaw) and straightness errors along linear axes are now commonplace and complement the existing positioning accuracy and repeatablity tests. More recently the subject of circularity evalutaion has also gained considerable interest. Here dynamic tests, using a kinematic ballbar or circular masterpiece, give an instant overview of the contouring ability of the machine in two axes at specific feedrates. This information is extremely important in optimising machining accuracy. This paper describes moves to complete the machine calibration package in national and international standardis- ation for the assessment of machine tool performance.