• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.4
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• pp.75-84
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• 2000

The main goal of our research is to compensate the milled surface errors induced by the tool deflection effects, which occur during the milling process. First, we predict cutting forces and tool deflection amount. Based on predicted deflection effects, we model milled surface shapes. We present a compensation methodology , which can generate a new tool trajectory, which is determined so as to compensate the milled surface errors. By considering manufacturing tolerance, tool path compensation is generalized. To validate the approaches proposed in this paper, we treat an illustrative example of profile milling process by using flat end mill. Simulation and experimental results are shown.

• Journal of Advanced Navigation Technology
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• v.26 no.4
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• pp.235-243
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• 2022

In this paper, in the case of an inertial navigation system, the posture estimation error in the initial alignment due to vertical deflection is analyzed. Posture estimation error due to DOV was theoretically analyzed based on the speed and posture error of INS. Simulations were performed to verify the theoretical grinding, and the results were in good agreement. For example, in the case of η=20", an alignment error of ϕ_N=0.00287°, ϕ_U=0.00196° occurred, and in the case of 𝜉=20", an error of ϕ_E= -0.00286° occurred. Through this, it was confirmed that the vertical posture error caused by the DOV occurred as a coupling characteristic of the INS posture error. It has been shown that an additional posture error may occur due to the DOV, which was not considered in the existing INS alignment, which means that correction for the DOV must be considered when applying high-precision INS.

• Design & Manufacturing
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• v.8 no.2
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• pp.1-6
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• 2014

The narrow-pitched connectors are of interest for small-scale devices such as smart phones because of theirs caling. We conducted an injection molding analysis and a warp analysis for 0.3mm and 0.5mm pitch FPC connectors. We obtained a volumetric shrinkage of 4.344%, a clamping force of 0.2529 tonne, a maximum injection pressure of 76.3 MPa as optimized molding conditions for the 0.3mm pitch FPC connector. We found that, compared with the traditional injection molding technique, the injection molding for narrow-pitched connectors comes with distinct features like low clamping force, high injection molding pressure, and narrow gate size. Adding to the optimization analysis, the deflection of 0.5mm pitch FPC connector was analyzed as well. A maximum deflection of 0.053mm was calculated, which the actual deflection of 0.062mm was compared to. The results deduced a relative error of 17%. We conclude that the deflection analysis along with the optimization analysis can be used as an effective tool to predict the behavior of narrow-pitch connectors although the relative error may need to improve.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.3
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• pp.68-74
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• 2001

In the drawing of large size automotive panels, elastic deflection of die components is induced by the contact force between them. The deflection is nonuniform and locally distributed, and results in nonuniform material flow. In order to arrange such a nonuniform die gap, a correcting operation, so called die spotting, is inevitable, which requires trial and error works and consuming time. A prediction of the bending deflection prior to a try-out must be useful to reduce the die spotting time. In this study, drawing process of a front fender is simulated first. and the deflection of the blank holder is calculated from the contact force imposing on th blank holder. The balance block heights ensuring a uniform deflection are optimized by the analysis and design of experiments.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.178-185
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• 2014

This paper describes a fabrication multiplexing sensor probe that employs a fiber Bragg grating(FBG) based on multiple measurements to determine the blade deflection of a wind power generator the reliability analysis of this probe is also presented. To diminish the temperature sensitivity of the FBG sensor, we form multiple CFRPs onto the upper and lower layers of the FBG and package it with an epoxy resin. As a result, the depth of the CFRP is 1mm, and the temperature sensitivity is $2.39pm/^{\circ}C$. We construct a sensor network utilizing the fabricated sensor with a blade beam model. As the number of pendulums is increased on the fore-end of the beam, the strain value is measured. The strain variation is calculated from the measurement of the load on the blade beam model by monitoring the strain of the FBG sensor. When the linear equation is applied, the strain error is 0.4% and when the finite difference method is used, the tip deflection error is 3.3%. The displacement error derived from the strain value of the FBG sensor is 4.39%. The calculated result between the measured value of the dead-end of the beam and the strain is less than 2.46% tip distortion error. Therefore, our proposed multiplexing sensor probe is a low-cost and high-reliability solution for a commercial wind power generator.

• Design & Manufacturing
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• v.13 no.1
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• pp.5-12
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• 2019

In this paper, we studied the micro tool deflection, micro cutting with low temperature, and deformation of micro ribs caused by cutting forces. First, we performed an integrated machining error compensation method based on captured images of tool deflection shapes in micro cutting process. In micro cutting process, micro tool deflection generates very serious problems in contrast to macro tool deflection. To get the real images of micro tool deflection, it is possible to estimate tool deflection in cutting conditions modeled and to compensate for machining errors using an iterative algorithm correcting tool path. Second, in macro cutting fields, the cryogenic cutting process has been applied to cut the refractory metal but, the serious problem may be generated in micro cutting fields by the cryogenic environment. However, if the proper low temperature is applied to micro cutting area, the cooling effect of cutting heat is expected. Such effect can make the reduction of tool wear and burr formation. For verifying this passibility, the micro cutting experiment at low temperature was performed and SEM images were analyzed. Third, the micro pattern was deformed by the cutting forces and the shape error occurred in the sidewall multi-step cutting process were minimized. As the results, the relationship between the cutting conditions and the deformation of micro-structure during micro cutting process was investigated.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.294-299
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• 2009

Micro end-milling has been becoming an important machining process to manufacture a number of small products such as micro-devices, bio-chips, micro-patterns and so on. Many related researches have given grand effects to micro end-milling phenomenon, for example, micro end-milling mechanism, cutting force modeling and machinability. This paper strongly concerned actual problem, micro tool deflection, which causes excessive machining errors on the workpiece. Machining error were predicted and measured through a series of test micro cutting and analysis of their SEM images and FEM analysis. Experiments are carried out to validate the approaches.

• Korean Journal of Computational Design and Engineering
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• v.4 no.3
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• pp.247-258
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• 1999

With the contemporary CAD/CAM system, where the tool path is generated and verified purely based on the geometric operation, geometric accuracy of the machined surface cannot be guaranteed dut to the cutting mechanics, meaning that the cutting mechanics should be incorporated in some fashion. In this paper, we incorporate the instantaneous cutting force and the tool deflection phenomena in predicting the machined surface for the finish-cut and milling operation. For the given NC dat including cutting conditions, the developed algorithm computes cutting force and deflection amount along the tool trajectory, and outputs the 3D graphic model of the machined surface together with error analysis. The validity and accuracy of the presented method has been tested by the actual cutting experiments. Experimental results and accuracy enhancement method together with implementing architecture of the VMCS (Virtual Machining CAM System) are discussed in the paper.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.647-648
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• 2010

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.55-63
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• 1999

The acceleration of the performance of machine tools influences the development of the semi-conductor and optical technology as the development of NC and measurement technology. Because the measurement has been done to unload condition without considering of mechanical stiffness in the case of machining center as we measure the quasi-static error of machine tools on general study people who works on the spot has many problems on the data value. Also there are no satisfiable results until now in spite of many studys about this because the deflections of the table and the shaft supporting a workpiece influence, influence the accuracy of the table and shaft supporting a workpiece influence the accuracy of the workpiece. And there is doubt about the inspection method of measured error. In this paper Therefor we will help working more accurately on the spot by measuring analyzing displaying the defoec-tion of the table and support shaft when we load on the table and the support shaft of machining center using laser interfer-ometer. Also we try to settle new conception of the measurement method and more accurate grasp of the deflection tenden-cy by verifing the tendency of the error measured through the comparison of the simulated error measured through the comparison of the simulated error using ANSYS a common finite element analysis program which is able to measure heat deformation material deformation and error resulted from this study.