• Journal of the Korean Vacuum Society
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• v.15 no.5
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• pp.512-517
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• 2006

A reliable linear translation system was constructed. The system has six piezo legs, attached to a main body, holding a hexagonal sapphire rod. The sapphire rod moves either forward or backward with the sequential motion of the piezo legs, driven by characteristic electric voltage waves. The translational system was tested in vertical direction. The speed of the sapphire rod was turned out to be constant during several mm travel. The slowest upward speed was measured to be ${\sim}1.7{\times}10^{-6}m/s$, yielding ${\sim}28.3nm/step$, while the slowest upward speed was ${\sim}3.7{\times}10^{-6}m/s$, with ${\sim}61.7nm/step$, due to gravitational force. The velocity increases linearly, as the amplitude of the voltage waves increases. The linear translation system will be used as a coarse approach part for a scanning tunneling microscope.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.311-314
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• 1997

According to the development of industrial equipment such as semiconductor manufacturing machines, optical device, and precision machine tool, a high-precision translation system with wide range has been required. This paper describes a high-precision 2-axis translation system, which consists of microstage and global stage. In order to achieve the highresolution in the long range, some engineering techniques are used. Three linear guides with flexible coupling are adopted to reduce the motor vibration in the global stage. A simple elastic hinge structure activated by five PZT is applied to reduce the angular dev~atlon. As the result of combination of microstage and global stage associated with some engineering techniques, the 2-axis translation system can measure the 200 X 200 mrn range with the nanometer accuracy.

• Korean Journal of Optics and Photonics
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• v.5 no.1
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• pp.138-143
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• 1994

A speckle correlation method was applied to measure the in-plane translation of a diffuse object which has rough surface using a linear CCD sensor and personal computer. Displacement of a speckle pattern produced from the object illuminated by a laser beam was measured by the cross-correlation functions between the I-D speckle profiles before and after the object translation, which were measured by linear CCD array sensor to be sent to IBM 386 personal computer. The sensitivity of the measurement was dependent on the radius of the wavefront curvature of incident beam as well as the spatial resolution of linear CCD array. A linear CCD array had 15 Jlffi pitch and 1728 pixels. The ratio of the speckle displacement and object translation varied from 1.03 to 5.20. The object translation of $3\mu\textrm{m}$ can be measured br the linear CCD sensor of which pitch was $15\mu\textrm{m}$, when the ratio of the speckle displacement and object translation was 5.20.s 5.20.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.78-84
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• 2001

The translation system is made up of springs, masses and a dashpot. This precise piece of equipment is controlled electro-mechanically by a motor and operating program. The control strategy of the system can be changed by spring stiffness, change of mass, and the damping coefficient of the dashpot. This system proves the necessity and effect of a closed loop control. In this paper, PD control experiments were implemented for the translation system. When the north falter was added on the PD controller, we compared the response characteristics of the two systems. The state feedback controller minimized scalar control gains and the resulting response characteristics of the system were studied using the LQR design. Finally, we improved the response characteristics of the translation system which are rising time, settling time, steady state error, and overshoot LQR was better as compared with PD control.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.109-114
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• 2000

A new method for the determination of camera system rotation and translation from in 3-D space using recursive least square method is presented in this paper. With this method, the calculation of the equation is found by a linear algorithm. Where the equation are either given or be obtained by solving five or more point correspondences. Good results can be obtained in the presence if more than the eight point. A main advantage of this new method is that it decouple rotation and translation, and then reduces computation. With respect to error in the solution point number in the input image data, adding one more feature correspondence to required minimum number improves the solution accuracy drastically. However, further increase in the number of feature correspondence improve the solution accuracy only slowly. The algorithm proposed by this paper is used to make camera system rotation and translation easy to recognize even when camera system attached at end effecter of six degrees of freedom industrial robot manipulator are applied industrial field.

• International Journal of Aerospace System Engineering
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• v.1 no.1
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• pp.29-33
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• 2014

A displacement measurement system that uses fiber-optical common-path interferometry has been developed. The system includes fiber-optic devices and a collimator attached to a linear translation stage. The interferometry effect was detected with a photodetector whose signal was measured on an oscilloscope. Experiments showed that vibration of the stage disturbed the signal by causing nanoscale interference. Under stable conditions, the measured distance was the almost the same as the value calculated from the linear translation stage parameters.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.49-53
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• 2007

In this study, we investigated experimentally the potential of a planer positioning mechanism with three degrees of freedom using a flexure guide and an electromagnetic linear motor. The goal was to produce a multi-axis positioning system with nanometric resolution over a 1-mm stroke. An $X-Y-\theta$ stage was designed based on previous results from a single-axis prototype and was constructed with a flexure guide mechanism and voice coil motor type linear actuators. We examined the necessity of a driving method and control system to ensure high resolution for multi-axis positioning. Experiments were conducted to evaluate the performance, and the results confirmed the mechanism's potential; fine point-to-point (PTP) positioning was achieved over a 1-mm stroke, with a resolution of 2 nm for translation in X-Y and 0.01 asec for yaw in $\theta$.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.6
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• pp.149-156
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• 2003

This paper proposes a face recognition method based on modified Otsu binarization, Hu moment and linear discriminant analysis (LDA). Proposed method is robust to brightness, contrast, scale, rotation, and translation changes. Modified Otsu binarization can make binary images that have the invariant characteristic in brightness and contrast changes. From edge and multi-level binary images obtained by the threshold method, we compute the 17 dimensional Hu moment and then extract feature vector using LDA algorithm. Especially, our face recognition system is robust to scale, rotation, and translation changes because of using Hu moment. Experimental results showed that our method had almost a superior performance compared with the conventional well-known principal component analysis (PCA) and the method combined PCA and LDA in the perspective of brightness, contrast, scale, rotation, and translation changes with Olivetti Research Laboratory (ORL) database and the AR database.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.567-570
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• 2006

The purpose of this study is to develope a linear feeder for uniform transportation of grains and to present its design guide line. so, It is measured the displacement of the front and rear aspect of the feeder in time domain. And the measured time signal is represented to the plane coordinate. From this process, it is presented the motion of the feeder in a harmonic excited condition. Also, It is determined whether translation motion or rotation motion. From these course, it is defined the optimized dynamic motion for uniform transportation of grains. It is included a ratio of the displacement and the angle which the dynamic motion between the front and rear aspect of the feeder.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.1
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• pp.83-95
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• 1999

Wavelet transform has localization for time or frequency. It is useful to analyze a nonstationary signal. Basic function on wavelet transform is generated dilating and translating the original wavelet(mother wavelet). In this paper, time-frequency analysis method using linear combination wavelet transform is proposed. And it is applied to diagnostic monitoring system using the proposed linear combination wavelet transform. The stationary and nonstationary signal is used linear chirp signal, fan noise signal, a sinusoid signal from revolution body, electronic signal. Transform applied to signal analysis use fast Fourier transform (FFT), Daubechies, Haar and proposed linear combination method. The result of time-frequency analysis using linear combination wavelet transform is suited for portraying nonstationary time signal as well as stationary signal. Also the diagnostic monitoring system carry out the effective the signal analysis.