• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.260-264
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• 2005

This paper describes the ultra precise position control of servo motor using sinusoidal encoder based on 'Arcsine Interpolation Method'. First, the paper theoretically analyzes and verify throughout experiments, the relationship between A/D converter input ripple and the total resolution to measure the precise position. Second, this paper presents a way to compensate the total gain and offset error by utilizing a low cost programmable differential amp, by which without any special expensive equipments they are easily on-line tuned and effectively compensated. Lastly, it was compared to servomotor position control characteristics using digital incremental 50,000ppr encoder. The test results show that, with much cheaper sinusoidal encoder, the proposed method exhibits better performance both in position control and ASD applications than the 50,000ppr optical encoder.

• Journal of applied mathematics & informatics
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• 제34권3_4호
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• pp.207-220
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• 2016

Our goal is to construct a two-frequency-dependent formula $I_N$ which interpolates a product f of two functions with different frequencies at some N points. In the beginning, it is not clear to us that the formula $I_N$ satisfies $I_N=f$ at the points. However, it is later shown that $I_N$ satisfies the above equation. For this theoretical development, a one-frequency-dependent formula is introduced, and some of its characteristics are explained. Finally, our newly constructed formula $I_N$ is compared to the classical Lagrange interpolating polynomial and the one-frequency-dependent formula in order to show the advantage that is obtained by generating the formula depending on two frequencies.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.681-684
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• 2008

Motion interpolation is adopted and has been spread widely into market since it is effective in reducing motion blur, which is considered as weak characteristic due to slow response time of liquid crystal and hold-type display. 120Hz driving using interpolated frames achieves better moving picture quality with less motion blur and less motion judder. However, errors in the interpolated frames can cause visual artifacts such as static text breakup, halos, and occlusions. This paper focuses on categorizing characteristics of visual artifacts and on reducing side-effects by using information from original frames in special cases.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.378-381
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• 2003

Efficient development of method on a performance evaluation for machine tools has been regarded as the most important work for accuracy and quality enhancement to every user and manufacturer. A evaluation method of accuracy for machine tools has been studied recently according to the rapid increase of interest in precision machine tools. To this point of view, the circular interpolation test of machine tools is recognized as the most useful method to distinguish a dynamic accuracy of NC machine tools by ISO and ANSI/ASME, etc. In this paper, we have studied and developed the form measurement system with grid encoder to analyse the final accuracy of NC machine tools. we have analyzed the servo system error and geometric error of NC machine tools through measuring a dynamic error signal by this system. and then we verified the experimental result and enhanced the reliability by means of comparing the characteristics of the developed system with the kinematic ball-bar system.

• 한국전자파학회논문지
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• 제10권2호
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• pp.257-266
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• 1999

In this paper, a spline-type divided-difference interpolation technique is proposed to efficiently evaluate the impedance matrix elements in the MoM analysis of layered medium problems. This method is combined with the fast computational method of the basis-expanded and tested dyadic Green's functions (expressed in the spectral domain integrals) in a recent literature. For the sake of its validity, the proposed method is applied to analyze the characteristics of a microstrip gap discontinuity, a microstrip filter, and an aperture coupled patch antenna. Numerical results obtained by this approach are in good agreement with those of other approaches.

• 대한기계학회논문집
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• 제19권1호
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• pp.38-44
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• 1995

We made a counter to measure the output of motor encoders for the motion error analysis of a CNC machining center, and have measured the dynamic characteristics and the position errors experimentally. Especially, we measured the radius errors for different feedrates and different radii when the CNC machining center performed a circular interpolation. We have also used an iterative learning method to reduce the radius errors and stick motion errors generated by the CNC machining center performing a circular interpolation. The results show that the proposed learning scheme can reduce the radius error and stick motion error significantly. The reduction of errors becomes more pronounced for higher feedrate and smaller radius.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.271-278
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• 2002

Soft ground has complex features in mechanic character of ground. Some problems about the settlement and transformation occur if the ground strength is comparatively weak and the depth is large. Therefore, we should consider physical and mechanical characters for safe, economical design and management. As the result of the course, we can compare them with those of field then solve the limitations which were came from the complex character of the soft ground. I have considered the soil's physical character (specific gravity of soil particles, moisture content, grain-size analysis etc) and mechanical character (direct shear test, consolidation, triaxial shear test etc), and then make out a linear interpolation by regression using the two, those and connection of the depth

• 한국공작기계학회논문집
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• 제12권5호
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• pp.67-72
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• 2003

For the analysis of Kirchhoff plate bending problems, a new meshless method is implemented. For the satisfaction of the $C^1$ continuity condition in which the first derivative is treated an another primary variable, Hermite interpolation is enforced on standard reproducing kernel particle method. In order to impose essential boundary conditions on solving $C^1$ continuity problems, shape function modifications are adopted. Through numerical tests, the characteristics and accuracy of the HRKPM are investigated and compared with the finite element analysis. By this implementatioa it is shown that high accuracy is achieved by using HRKPM for solving Kirchhoff plate bending problems.

• Journal of Power Electronics
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• 제6권2호
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• pp.139-145
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• 2006

This paper describes the ultra precise position estimation of a servomotor using a sinusoidal encoder based on Arcsine Interpolation Method for the cost reduction of circuit design. The amplitude and offset errors of the sinusoidal encoder output signals, from the encoder itself and analog signal processing procedures, are effectively compensated and on-line tuned by utilizing a low cost programmable differential amplifier without any special expensive equipment. For a theoretical evaluation of the practical resolution of this system, the relationship between the amplitude of ADC(Analog to Digital Converter) input signal errors and the anticipated resolution is also addressed. The performance of the proposed method is verified by comparing it with speed control characteristics of the servomotor driving system using a digital incremental 50,000ppr encoder in the experiments.

• 전기학회논문지
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• 제66권12호
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• pp.1751-1758
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• 2017

This paper presents a fuzzy logic system with data preprocessing to make the accurate electric power load prediction system. The fuzzy logic system acceptably treats the hidden characteristic of the nonlinear data. The data preprocessing processes the original data to provide more information of its characteristics. Thus the combination of two methods can predict the given data more accurately. The former uses TSK fuzzy logic system to apply the linguistic rule base and the linear regression model while the latter uses the linear interpolation method. Finally, four regional electric power load data in taiwan are used to evaluate the performance of the proposed prediction system.