• Journal of the Korean Society for Precision Engineering
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• v.14 no.7
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• pp.15-21
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• 1997

This paper presented a linear motion accuracy by using two-dimensional probe with the master block and the square for NC machine tools. This measuring system could be measured motion error due to numerical control system. The results of measurement and simulation for motion error were similar, and so, this system had enough accuracy to measure a linear motion accuracy for NC machine tools. The experimental results are as follows. 1. This measuring system could be measured motion error due to mumerical control system. 2. The results of measurement and simulation for motion error were similar. 3. This measuring system had enough accuracy to measure a linear motion accuracy for NC machine tools.

• Journal of the Korea Computer Industry Society
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• v.8 no.3
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• pp.181-186
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• 2007

The movement in the closed system's internal and external, consists of linear open motion and linear closed motion, as well as non-linear motion and non-linear closed motion. When the linear closed motion receives external forces such as friction, closed motion is activated. It explains that even closed rotating systems that are subjected to external forces such as friction becomes a confined rotating system. Through fluid experiments the closed rotating system and confined system's quantitative data was observed and closed rotating system was confirmed to formulate the computer simulation function model concerning closed motion and confined motion. A basic graphic configuration of the motion device is also introduced.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.275-284
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• 2011

The accuracy simulation technology of linear motion system is introduced in this paper. Motion errors and positioning errors are simulated using informations on the design parameters of elements of linear motion system. 5 Degree-of-freedom motion error analysis algorithm utilizing the transfer function method and positioning error analysis algorithm which are main frame of accuracy simulation are introduced. Simulated motion errors are compared with experimental results for verifying the effectiveness. Then, using the proposed algorithms, simulation is performed to investigate the effects of ballscrew and linear motor on the motion errors. Finally, the influence of feedback sensor position on the positioning error is also discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.966-971
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• 2008

Free-piston engine system is a new type energy converter which uses a linear motion of piston by using linear generator. In free-piston engine system, the piston is not connected to a crank-shaft. The major advantages of free-piston engine system are high efficiency and low mechanical loss from the absence of motion conversion devices. Linear generator of free-piston engine system is used as generator and starting motor. In design step, considering of back-emf and detent force characteristics for generating mode and thrust and control characteristics for starting mode is needed. In this research, generating mode of flat-type linear generator and tubular-type linear generator is analyzed by finite element analysis method and starting mode of both type linear generators is analyzed by using capability curve. Capability curve is plotted from electrical parameters of both type linear generator and motion profile is calculated from mechanical parameters.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.7
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• pp.101-106
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• 2004

Measurements of linear motion accuracy for one axis of NC lathe have achieved with laser interferometer system, but measurement of plane motion accuracy for two axes on zx-plane of NC lathe have not achieved with the above system. Therefore in this study, measuring unit system is organized using two optical linear scales in order to acquire error. data during of plane motion of ATC(Automatic Tool Change.) of NC lathe by reading zx-plane coordinates. Two optical linear scales of measuring unit are fixed on zx-plane of NC lathe, and moving part of the scales are fixed to the ATC and then error motion data of z, x-coordinates of the ATC are received from the scales through the PC counter card inserted in computer at constant time intervals using tick pulses coming out from computer. And then, error motion data files acquired from measuring are saved in computer memory and the aspect of plane motion are modeled to plots, and range of the error data, means. average deviations, and standard deviations etc. are calculated by means of statistical treatments using computer programs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.2
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• pp.137-143
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• 2011

The pitch motion of a gravity-gradient satellite can be chaotic, depending on the ratio of mass moments of inertia and the eccentricity of the satellite orbit. For a precise prediction of motion, chaotic pitch motion has to be changed to non-chaotic motion. Feedback control can be used to obtain nonchaotic pitch motion. For chaos control and stabilization of the pitch motion of a gravity-gradient satellite, a feedback control system is designed, based on the linear nonautonomous system obtained by linearizing the nonlinear pitch motion. The control law obtained has two parameters and is applied to chaotic nonlinear pitch motion. The nonlinear control system satisfies the proposed control objectives in the range of the nonchaotic parameter space.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1144-1149
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• 2003

It is very important to measure circular motion accuracy of NC lathes it affects accuracy, performance, interchange ability and quality of machine parts machined by the NC lathes in industries. So, in this study, measuring units system to measure circular motion accuracy two axes circular motion accuracy of NC lathes was composed of two optical linear scales installed on the z and x-axes of work coordinate system on NC lathe and a computer inserted with PC counter card enables to obtain measuring data. Here, ATC(Automatic Tool Changer) and moving part of linear scales are fixed with magnet bases in order to measure circular motion accuracy of the ATC of NC lathe. And next, computer software was developed in order to measure the circular motion accuracy of NC lathe under resolution of 0.1 $\mu\textrm{m}$ using two linear scales, and also computer softwares were developed so that measuring data could be modeled on plots and be analyzed numerically,

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.215-220
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• 2002

Recently, linear motor has been developed for linear motion of machine tools. Linear motor is useful to design the linear motion, high speed and high accuracy, because of the simple system not required the additional mechanical part such as coupling and ballscrew. This paper tested performance of linear motor relevant to motioning and positioning table such as F.R.F., step response and positional accuracy Linear motion system using linear motor requires the effective cooling system because it cause to decrease the positional error and to protect the motor coil. Therefore the positional error measurement was made to evaluate the effect of the temperature variation.

• Journal of Power System Engineering
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• v.21 no.1
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• pp.18-23
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• 2017

The Stokes waves representing the deep sea waves are expressed as a superposition of several linear waves. To evaluate the motions of floating bodies in the deep seas, it is necessary to evaluate the motions of the bodies in the Stokes waves. The 5th-order Stokes waves are expressed as a superposition of 5 linear waves. Therefore, the motion responses of the bodies in the Stokes waves would be expressed as a superposition of the motion responses of the bodies in the each linear waves. In this research, The experimental results were compared with the numerical results in linear waves and Stokes waves.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.3
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• pp.58-66
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• 1995

It is very important to test motion accuracy and performance of NC machine tools as they affect that of all other machines machined by them in industry. In this paper, in has become possible to detect errors of linear displacement of radial direction for circular motion test using newly assembled magnetic type of linear scales so called Magnescale ball bar system, and to calculate time interval getting error motion data and revolution angle of circular motion in machining center using tick pulses come out from computer. And a set of error data gotten from test is expressed to a plot by computer treatment and to numerics of error motion by statistical treatment and results of test are compared with those of Renishaw ball bar system.