• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.625-629
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• 1998

So far a single-axis controlled repulsive type magnetic bearing system have been designed and fabricated in our laboratory employing the repulsive forces operating between the stator and rotor permanent magnet for levitation. The radial axis is uncontrolled passive one. The higher speed of operation is limited due to the vibration along the uncontrolled axis and the increase of control current due to eddy current interference. This paper will discuss a detailed modeling of the repulsive type magnetic bearing system for five axis control including the eddy current effect and the method of reduction of eddy current effect. Simulation results using Matlab will be presented.

• Land and Housing Review
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• v.2 no.2
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• pp.171-182
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• 2011

Current state of population, the existing roads, and the function of roads and highways of North Korea have been reviewed in this paper. In addition, the 'Five by five' road network has proposed for North-South and East-West directions to be connected with the road network of South Korea, China, and Asian Highways. Furthermore, the evaluation criteria and weighted values have suggested to determine the investment priority of highway based on the survey results from expert group members using AHP analysis method. Throughout the analysis, the ranking of the investment priority has been decided for the North-South axis and East-West axis. The second North-South axis (Geasung-Pyungyang-Anju-China) has been ranked as the first priority for the North-South axis followed by the fifth North-South axis as the second, the first axis as the third, the third axis as the fourth and the fourth axis as the last priority. For the East-West axis, the second East-West axis(Nampo-Pyungyang-Wonsan) has been ranked as the first priority followed by the first axis as the second, the third axis as the third, the fourth axis as the fourth and the fifth East-West axis as the last priority.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.2012-2022
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• 1993

For the machining of the sculptured surfaces on 5-axis CNC milling machine, the milling cutter direction vector was determined in the study (I) with 5-axis post-processing. Thus, it was possible to cut the sculptured surfaces on five-axis CNC milling machine with the end mill cutter. Then, for smooth machined surfaces in five-axis machining of free-from surfaces, this study develops an algorithm for prediction of cusp heights. Also, it generates tool path such that the cusp heights are constrained to a constant value or under a certain value. For prediction of the cusp height between two basis points, a common plane, containing the line crossing two basis points and the summation vector of two normal vectors at two basis points, is defined. The cusp height is the maximum value of scallops on the common plane after end mill cutter passes through the common plane. Sculptured surfaces were machined with CINCINNATI MILACRON 5-axis machining center, model 20V-80, using end mill cutter. Cusp heights were verified by 3-dimensional measuring machine with laser scanner, WEGU Messtechnik GmbH.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1012-1016
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• 2004

In this paper, we propose a simple but optimized NC code generating technique for disk cams by means of tool path error control in a five-axis CNC machining center. Using the geometric theorem of the triangle made between manufacturing points and error checkpoint, the tool path error has been studied for disk cams profile generation and an improvement in the profile has been obtained. Then, based on the present manufacturing approach a computer program is developed on $C^{++}$ language to perform and to verify the shape design, the manufacturing simulation, and the optimized generation of the NC code.

• Journal of Sensor Science and Technology
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• v.21 no.3
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• pp.192-197
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• 2012

This paper describes the control of the hand fixing system attached to the finger rehabilitation robot for the rehabilitation exercise of patient's fingers. The finger rehabilitation robot is used to exercise the finger rehabilitation, and a patient's hand is safely fixed using the hand fixing system. In this paper, the hand fixing system was controlled with PD gains to fix a palm of the hand, and the characteristic test for the hand fixing system was carried out to sense the fixed hand movement of the front and the rear, that of the left and the right, and that of the upper. It is thought that the hand fixing system could safely fix the hand, and the movement of the fixed hand could be perceived using the five-axis force/moment sensor attached to the hand fixing system.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.8
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• pp.705-711
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• 2015

Five-Axis machines can generate undesirable defects such as the undercutting and overcutting errors that frequently occur in the three-axis machining process. It is therefore necessary to develop a program for NC-code generation, whereby the cutter posture is considered to decrease the occurrence of defects. In previous studies, the Easy-Impeller CAM(E-ICAM), an automatic CAM program used for the five-axis machining of impellers, was developed; however, when E-ICAM is used to machine an impeller, it is possible to gouge the hub and blade. Therefore, the aim of this study is the establishment of a formula for each type of endmill to minimize gouging according to the cutter posture, in consideration of several factors that affect accuracy in the machining of an impeller. This study also aimed to improve the performance and accuracy of E-ICAM in the manufacturing of impellers.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.1-6
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• 2014

This paper describes a method of estimating and evaluating the volumetric errors of multi-axis machine tools. The estimation method is based on a generic model that was developed from conventional kinematic error models for the geometric and thermal errors to help predict the volumetric error easily in various configurations. To demonstrate the advantages of the model, an application in the early stages of a five-axis machine tool design is presented as an example. The model was experimentally evaluated for a four-axis machine tool by using the data from ISO230-6 and R-test measurements to compare the estimated and measured volumetric errors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.19-20
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1017-1018
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• 2010

• Journal of the Korean Society for Precision Engineering
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• v.26 no.10
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• pp.7-11
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• 2009