• 한국정밀공학회지
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• 제23권2호
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• pp.57-64
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• 2006

Optical filters in WDM are passive communication components used in case of transmitting and reflecting lights with specific wavelengths. In this paper, a novel mechanism for the automatic and optical alignment has been presented. It includes minimum axes not to be coupled each other. The automatic spectrum inspection system has been developed to improve the alignment time of reference optical ray, spectrum inspection time and inspection quality, simultaneously. It has been confirmed that the proposed spectrum inspection system is faster, more precise and more reliable than those based on the conventional handwork.

• 음성과학
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• 제9권4호
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• pp.265-274
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• 2002

In this paper we propose an automatic segmentation system that outputs the time alignment information of phoneme boundary using Viterbi search with HMM (Hidden Markov Model) and corrects these results by an UVS (unvoiced/voiced/silence) classification algorithm. We selecte a set of 39 monophones and a set of 647 extended phones for HMM models. For the UVS classification we use the feature parameters such as ZCR (Zero Crossing Rate), log energy, spectral distribution. The result of forced alignment using the extended phone set is 11% better than that of the monophone set. The UVS classification algorithm shows high performance to correct the segmentation results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.302-302
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• 2000

This paper presents the measurement and correction of PCB alignment errors for PCB-manufacturing machines. The conventional PCB-manufacturing machine doesn't have enough accuracy to accommodate the demand for high-resolution circuit pattern and high-density mounting capacity of electronic chips. It is because of alignment errors of PCB loaded to the PCB-manufacturing machine. Therefore, this study focuses on the development of the system which is able to measure and correct alignment errors whit high-accuracy. An automatic optical inspection part measures the PCB alignment error using two cameras, and the high-accuracy 3-axis stage makes correct of these error. The operating system is run in the environment of Window 98 (or NT). Finally we implemented this system to PCB screen printer and PCB exposure system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.390-393
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• 2005

he FPCs(Flexible Printed Circuit) are currently used in several electronic products like digital cameras, cellular phones because of flexible material characteristics. Because the FPC is usually small size and flexible, only one FPC should not enter chip mounting process, instead, several FPCs is placed on the large rigid pallette and go to the chip mounting process. Currently the job of mounting FPC on the pallette is carried by totally manual way. Thus, the goals of the research is develop the automatic machine of FPC mounting on pallette using vision alignment. The procedure of operating machine is firstly to measure alignment error of FPC, correct alignment errors, and finally mount well-aligned FPC on the pallette. The vision technology is used to measure alignment error accurately, and precision motion control is used in correcting errors nd mounting FPC. The two picker heads handling two FPC together is used to increase the productivity.

• 산업기술연구
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• 제22권B호
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• pp.241-249
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• 2002

Optical fiber is indispensable for optical communication systems that transmit large volumes of data at high speed, but super precision technology in sub-micron units is required for optical axis adjustment. We developed the automatic optical fiber by image processing and automatic loading system. we have developed 6-axis micro stage system for I/O optical fiber arrays, the initial automatic aligning system software for a input optical array by the image processing technique, fast I/O-synchronous aligning strategy, the automatic loading/unloading system and the automatic UV bonding mechanism. In order to adjust the alignment it used on PC based motion controller, a $10{\mu}m$ repeat-detailed drawing of automatic loading system is developed by a primary line up for high detailed drawing. Also, at this researches used the image processing system and algorithm instead of the existing a primary hand-line up and fiber input array and waveguide chip formed in line by automatic.

• 한국정밀공학회지
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• 제20권6호
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• pp.88-95
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• 2003

This paper presents the measurement and correction method of PCB alignment errors for PCB screen printer. Electronic equipment is getting smaller and yet must satisfy high performance standard. Therefore, there is a great demand for PCB with high density. However conventional PCB screen printer doesn't have enough accuracy to accommodate the demand fur high-resolution circuit pattern and high-density mounting capacity of electronic chips. It is because the alignment errors of PCB occur when it is loaded to the screen printer. Therefore, this study focuses on the development of the system which is able to measure and correct alignment errors with high-accuracy. An automatic optical inspection part measures the PCB alignment errors using machine vision, and the high-accuracy 3-axis stage makes correction for these errors. This system used two CCD cameras to get images of two fiducial marks of PCB. The geometrical relationship between PCB, cameras, and xy$\theta$ stage is derived, and analytical equations for alignment errors are also obtained. The unknown parameters including camera declining angles and etc. can be obtained by initialization process. Finally, the proposed algorithm is verified by experiments by using test bench.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.545-549
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• 1993

an alignment system in the X-and Y-directions an X-Y-.theta. stage driven by piezoelectric actuators is presented. A pair of quadruple gratings and a quadruple photo-detector are used. The difference between the two 0-th order moire signals in reflection with a relative spatial phase of 180.deg. is used in each direction to control the alignment of the X-Y-.theta. stage. The stage is aligned at the position where the difference is zero. The quadruple gratings are 10 mm * 10 mm, and of a binary square-type with a 1/2 duty cycle. Their pitches are 16 .mu.m. Alignment accuracy of .+-.20nm was obtained in this system.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.219-224
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• 2004

In recent years, as the demands of VBNS(Very high speed Backbone Network Service) and VDSL(Very high-data rate Digital Subscriber Line) increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, WDM elements increase. The alignment and the attachment technology are very important to fabricate the optical elements for communication. In this paper, the mechanism of rotational stage, the contact sensing unit, and integrated control circuit for the optical alignment system are studied.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1926-1927
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• 2011

In this paper, an alignment method between a transporter and a stowage is presented for the automation of loading and unloading operations in the mobile harbor system. The principle of linetracer is utilized for the automatic alignment of transporter and stowage, and the effectiveness of the alignment method is proved by a simulated experiment using mobile robot.

• Journal of Computational Design and Engineering
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• 제1권4호
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• pp.223-232
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• 2014

This paper describes a variant of the extended Gaussian image based registration algorithm for point clouds with surface color information. The method correlates the distributions of surface normals for rotational alignment and grid occupancy for translational alignment with hue filters applied during the construction of surface normal histograms and occupancy grids. In this method, the size of the point cloud is reduced with a hue-based down sampling that is independent of the point sample density or local geometry. Experimental results show that use of the hue filters increases the registration speed and improves the registration accuracy. Coarse rigid transformations determined in this step enable fine alignment with dense, unfiltered point clouds or using Iterative Common Point (ICP) alignment techniques.