• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.05a
• /
• pp.703-707
• /
• 2000

Machine tool errors have to be characterized and predicted to improve machine tool accuracy. A real-time error compensation system has been developed based on volumetric error synthesis model which is composed of machine tool errors. This paper deals with new algorithm about verification of machine tool errors. This new algorithm uses a simplified volumetric error synthesis model. This simplified model is constructed with only main components among the error components of the machines. This main error components are analyzed by three-dimensional helical ball bar test. By substituting result of helical ball bar test fer simplified model, we could find that obtained error components are closed to real error components.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.9
• /
• pp.127-134
• /
• 1998

This paper describes the design of a 6-component force/moment calibration machine with having the maximum capacities of 500 N in forces and 50 Nm in moments. To be used for the characteristic of a multi-component load cell. this machine consists of a body, a fixture, a force generating system, a moment generating system and weights. We have also evaluated the accuracy of the calibration machine. Test results show that the expanded relative uncertainty for force components $\pmFx,\;\pmFy\;and\;moment\;components\;\pmMx,\;\pmMy\;are\;less\; than\;8.6\times10^{-4}$, and force components +Fz, -Fz and moment components $\pmMz\;is\;less\;than\;1.6\times10^{-3},\;2.0\times10^{-5},\;1.7\times10^{-3}$ respectively.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.3
• /
• pp.143-151
• /
• 2001

Machine tool errors have to be characterized and predicted to improve machine tool accuracy. A real-time error compensation system has been developed based on volumetric error synthesis model which is composed of machine tool errors. This paper deals with new algorithm about verification of machine tool errors. This new algorithm uses a simplified volumetric error synthesis model. This simplified model is constructed with only main components among the error components of the machine. The main error components are analyzed by ball bar test of hemispherical helix. The novel measurement method using ball bar system has many advantages which are more efficient, easier to use than conventional measurement system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2005.05a
• /
• pp.435-440
• /
• 2005

This study describes a new method of constructing Reconfigurable machine tools configurations from a set of modules or components. This proposed method defines combinability vector for each module and mutual combinability coefficient matrix for adjacent two modules. All of machine configurations possible to be generated from any two adjacent modules can be determined by quadratic form of two associated combinability vectors. Furthermore, all of possible RMT configurations generating from a series of multiple modules also can be obtained by multiplying quadratic form of two adjacent conbinability vectors recursively. Our proposed RMT configuration generating method can be successfully applied to determining all of possible machine configurations from several modules or components at conceptual- or preliminary- design stage.

• Journal of Drive and Control
• /
• v.9 no.4
• /
• pp.26-31
• /
• 2012

Friction reduction between sliding hydraulic machine components is required to improve efficiency and reliability of hydraulic machineries. It is recently reported that surface texturing on sliding bearing surfaces can reduce the friction force highly. In this paper, numerical analysis is carried out to investigate the effect of dimple numbers and inlet boundary pressures on the lubrication characteristics of a parallel sliding bearing using a commercial computational fluid dynamics (CFD) code, FLUENT. The results show that the pressure distribution, load capacity, dimensionless friction force and leakage with dimple number and their locations, and inlet pressures. The overall lubrication characteristics are highly affected by dimple numbers and boundary pressure. The numerical method adopted and results can be used in design of efficient hydraulic machine components.

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.3
• /
• pp.249-254
• /
• 2004

The radiation dosage of nuclear fuel handling machine of PHWR type NPP during normal operation is measured using semiconductor detectors. In order to predict and mitigate the damage of main components in fuel handling machine, caused by high irradiation, the radiation dosage exerted to the components by neutron and gamma ray is measured independently during one time of the fuel exchange, which is used far estimating the radiation dosage for one year. This result can guarantee the safety and economical efficiency for determining the replacement time of the high cost main components in fuel handling machine.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10a
• /
• pp.589-594
• /
• 1991

Group Technology (GT) is a technique for identifying and bringing together related or similar components in a production process in order to take advantage of their similarities by making use of, for example, the inherent economies of flow production methods. The process of identification, from large variety and total of components, of the part families requiring similar manufacturing operations and forming the associated groups of machines is referred as 'machine-component grouping'. First part of this paper is devoted to describing a hierarchical divisive algorithm based on graph theory to find the natural part families. The objective is to form components into part families such that the degree of inter-relations is high among components within the same part family and low between components of different part families. Second part of this paper focuses on establishing cell design procedures. The aim is to create cells in which the most expensive and important machines-called key machine - have a reasonably high utilization and the machines should be allocated to minimize the intercell movement of machine loads. To fulfil the above objectives, 0-1 integer programming model is developed and the solution procedures are found. Next an attempt is made to test the feasibility of the proposed method. Several different problems appearing in the literature are chosen and the results air briefly showed.

• Journal of Auto-vehicle Safety Association
• /
• v.8 no.2
• /
• pp.17-23
• /
• 2016

Construction of our machine "Digital Tacho Graph" toghether with development and intergrated management system information is attached under Traffic Safety Law in article submission. This machine "Digital Tach Graph" has been mandated on a priority basis. The entire machine is constructed with specialised components to collect data that can retrive basic information. To obtain the components to perfect the information to optimize the device and system.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1559-1563
• /
• 2007

This paper presents a virtual machine design simulation program. Kinematics of various mechanisms can be modeled with 3 dimensional geometry and actuators. CAD data for any machine component can be easily imported in STL format. Machine components are assembled with kinematic joints simply by drag and drop function in virtual graphic simulator. Interference and collision of any component with other components can be identified during the motion simulation. Graphic user interface program is developed using Microsoft Direct X code. A precision micro stage system is demonstrated with the proposed virtual machine design simulator.

• 연구논문집
• /
• s.25
• /
• pp.5-12
• /
• 1995

Mold platen are one of the most important structural components of the injection molding machine. Mold platen had been designed, and manufactured based on the experience and the method of trial and error. Recently, as the computer progress, the numerical simulation method using commercial finite element analysis code has been used to analyze the characteristics of components. It's a urgent problem to reduce the weight of mold platen while preserving the safety and reliability for the structual failure. Finite element analyses to establish basic design technologies and reducing the weight of mold platen were carried out. As result, we are obtained the about 10% reducing the weight for mold platen.