• 한국군사과학기술학회지
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• 제4권1호
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• pp.225-233
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• 2001

This paper deals with the transfer alignment problem of SDINS(StrapDown Inertial Navigation System) subjected to roll and pitch motions of the ship. Specifically, to reduce alignment errors induced by measurement time-delay and ship body flexure, an error compensation method is suggested based on delay state augmentation and DCM(Direction Cosine Matrix) partial matching. A linearized error model for the velocity and attitude matching transfer alignment system is first derived by linearizing the nonlinear measurement equation with respect to its time delay and augmenting the delay state into the conventional linear state equations. And then DCM partial matching is properly combined to reduce effects of a ship's Y axis flexure. The simulation results show that the suggested method is effective enough resulting in considerably less azimuth alignment errors.

• 소성∙가공
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• 제13권3호
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• pp.190-204
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• 2004

The objective of this study is to develop a highly accurate micro tool alignment system applicable to the micro machining technology. In a specific application such as micro hole punching, radial clearance between micro tools is order of a few micron. Under this micron scale tool clearance, accuracy of tool alignment is very important for ensuring hole quality. In the present study, a two-way image acquisition system was developed, which can produce overlapped image of both micro tools that face each other, and applied to the tool alignment in the micro punching. Also, to meet alignment accuracy of tools within $1\mu\textrm{m}$, the cross correlation image processing algorithm was employed. With this system, $25\mu\textrm{m}$ punching tools with $1\mu\textrm{m}$ radial clearance could be accurately aligned.

• 한국항공우주학회지
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• 제35권5호
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• pp.419-425
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• 2007

수직발사를 위한 스트랩다운 관성항법시스템의 급속 One-Shot정렬 기법을 제시한다. 제시된 정렬기법은 종 항법시스템(Slave INS)의 가속도계 출력 값 및 주 항법시스템(Master INS)의 자세를 이용한다. 또한 정렬 성능 및 속도를 개선시키기 위하여 등가선형변환 및 사전 필터링 기법을 제시한다. 시험결과들은 제시된 방법이 정렬 정확도 및 정렬 속도 개선에 효과적임을 보였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.856-859
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• 1996

In this paper, a coarse alignment algorithm for strapdown inertial navigation system is proposed and evaluated analytically. The algorithm computes roll and pitch angles of the vehicle using accelerometer outputs, and then determines yaw angle with gyro outputs. It is referred, as two-step coarse alignment in this work. With the geometric relation between sensor outputs and roll, pitch and yaw angles, the algorithm error is analytically derived and compared with the previous coarse alignment algorithm introduced by Britting. The results show that the proposed two-step coarse alignment algorithm has better performance for pitch angle computation.

• Journal of Information Display
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• 제12권4호
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• pp.173-177
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• 2011

The alignment film abrasion caused by the rubbing process was quantitatively evaluated via atomic-force microscopy (AFM). First, a patterned alignment film structure, which was molded through the imprint method, was artificially formed. Then, the surface topography of the alignment film was evaluated via AFM after rubbing, and the degree of abrasion of the alignment film was estimated by subtracting the value after rubbing from the value before rubbing. It was recognized that the degree of abrasion increased with an increase in the rubbing strength. The relationship between the number of rubbing cycles and the degree of abrasion of the alignment film was also estimated.

• 제어로봇시스템학회논문지
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• 제14권4호
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• pp.369-375
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• 2008

The kinematics and control problem of a visual alignment system is investigated, which plays a crucial role in the fabrication process of flat panel displays. The first solution is the inverse kinematics of a 4PPR parallel alignment mechanism. It determines the driving distance of each joint to compensate the misalignment between mask and panel. Second, an efficient vision algorithm for fast alignment mark recognition is suggested, where by extracting essential feature points to represent the geometry of a mark, the geometric template matching enables much faster object recognition comparing with the general template matching. Finally, the overall visual alignment process including the kinematic solution, vision algorithm, and joint control is implemented and experimental results are given.

• Journal of Advanced Marine Engineering and Technology
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• 제3권1호
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• pp.32-39
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• 1979

Alignment of marine engine shafting generally implies a judicious slope alignment of supporting bearings in order to achieve acceptable values of bearing reactions and shaft stresses for all deformation conditions of hull. Authors developed a computer program, which computes the bearing reaction forces, the bearing reaction influence numbers and etc, using quadruple integration method. And the results of calculation for a 26,000 DWT steam container carrier were in good agreements with those of foreign shipyard. Also they introduced the optimization technique of slope alignment combined technical economic basis, and as a result of comparing characteristics of shafting in case of straight alignment whit those in case of slope alignment, the latter was found to be much better than the former.

• 한국기계가공학회지
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• 제6권3호
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• pp.24-30
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• 2007

The 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 are placed on the large rigid pallette and enter into 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. Instead of using two cameras or using moving one camera, the proposed vision system with only one fixed camera is adopted. Moreover, the two picker heads which can handle two FPCs simultaneously are used to make process time shortened. The procedure of operation 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 and mounting FPC.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.551-554
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• 2000

Alignment system is a system to locate an object to it's accurate position in multi-d.o.f space. According to process of application, it is need to align an object in 3 or 6 d.o.f. space. And alignment system is used in various environments. Especially in PDP application, alignment process is carried out in vaccume environment. In this paper, we developed 3 d.o.f. alignment system for vaccume environment, performed kinematic analysis and improved it's positional accuracy.

• 소음진동
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• 제8권5호
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• pp.922-928
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• 1998

This paper presents the automatic alignment measuring system for improving the accuracy and working time of alignment of large vertical hydraulic pump turbine. It is general practice that rotating shaft should run within acceptable vibration limit. In order to obtain better run-out data of multi-stage rotor, careful and accurate alignment approach must be established. Generally, present alignment procedure are required several iterative works and so many manpower. Therefore, the new system has been developed using a vector calculation algorithm, laser sensor and data acquisition devices. As a result of appling to actual machines, it is confirmed that manpower is saved up to an average 90%.