• 한국생산제조학회지
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• 제5권2호
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• pp.63-72
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• 1996

In order to regulate the cutting force at a desired level during peripheral end milling processes a feedrate override Adaptive Control Constraint (ACC) system was developed. The feedrate override function was accomplished through a development of programmable machine controller (PMC) interface technique on the NC controller, Nonlinear model of the cutting process was linearized as an adaptive model with a time varying process parameter. An integral type estimator was introduced for on-line estimation of the cutting process parameter, Zero order hold digital control methodology which uses pole-assignment concept for tuning of PI controllers was applied for the ACC system. Performance of the ACC system wsa confirmed on the vertical machining center equipped with fanuc OMC through a large amount of experiment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.817-821
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• 1997

Ever since the nonlinearity of machine tool dynamics was established, researchers attempted to make use of this fact to devise better monitoring, diagnostics and system, which were hitherto based on linear models. Theory of chaos, which explains many nonlinear phenomena comes handy for furthering the analysis using nonlinear model. In this study, measuring system will be constructed using multi-sensor (Tool Dynamometer, Acoustic Emission) in end millingprocess. Then, it will be verified that cutting force is low-dimensional deterministic chaos calculating Lyapunov exponents, Fractal dimension, Embedding dimension. Aen it will be investigated that the relations between characteristic parameter caculated form sensor signal and tool wear.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.975-979
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• 2002

This paper studies the indirect parameters when the new and worn end mill working in the machining center. The parameter output methods are cutting force, current values and AE signals. In the result, when the worn end mill operating, cutting forces increase the 14.71〔N〕, current values increase the 2.917〔A〕 and 1.168〔A〕 according to the spindle mote. and feed motor, and AE signals increase the 0.588$\times$10$^{-5}$ 〔A〕. We can use these parameters in the detection of end mill wear.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.47.1-47
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• 2001

The drilling process has a great importance for the production technology due to its widerspread use in the manufacturing industry. In order to enhance a maximum production rate and prevent the drill from the damage, it is important to monitor and control the drilling system. Thrust force and cutting torque are the main output variables in the design of drilling control systems. In this paper, an alternative estimation method of thrust force by using flexible neural networks is proposed. Flexible neural network uses the sigmoid activation function with adjustable parameter in order to enhance the approximation accuracy ...

• 대한기계학회논문집
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• 제19권3호
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• pp.713-723
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• 1995

In intelligent machine tools, a computer based control system, which can adapt the machining parameters in an optimal fashion based on sensor measurements of the machining process, should be incorporated. In this paper, the technology for adaptively optimizing the cutting conditions to maximize the material removal rate in face milling operations is proposed using the exterior penalty function method combined with multilayered neural networks. Two neural networks are introduced ; one for estimating tool were length, the other for mapping input and output relations from experimental data. Then, the optimization of cutting conditions is adaptively implemented using tool were information and predicted process output. The results are demonstrated with respect to each level of machining such as rough, fine and finish cutting.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.27-33
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• 1999

In order to regulate cutting force at a desired level during NC lathe process, a feedrate override Adaptive Control Constraint system was developed. Nonlinear model of the cutting process was linearized as an adaptive model with a time varing process parameter. Performance of the ACC system was confirmed on the NC lathe equipped with the developed NC system through a large amount of experiment.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.83-88
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• 2001

In order to suggest the proper optimal conditions of the CNC milling machining for the Thin-wall surface, some experiments were carried out. The process was applied in the aerospace industry for the machining of light alloys, notably aluminium. In recent year, however, the mold and die industry has begun to use the technology for the production of components, including those manufactured from hardened tool steels. And the end mill is an important tool in the milling process. A typical example for the end mill is the milling of pocket and slot in which a lot of material is removed from the workpiece. Therefore the proper selection of cutting parameter for end milling is one of the important factors affecting the cutting cost. In this paper, we choose the optimal parameters(cutting forces) to cut thin-walled Al part by experiment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.1001-1004
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• 2000

As tools for machining precision components, end mills and ball end mills are widely used. For the end mills have longer cylindrical shape comparing diameter, liable to deflect and induce deterioration of surface roughness. Tool geometry parameters and cutting process have complex relations with each other. So, It is hard to determine hew to select optimal tool geometry. So, to improve the stiffness, relationship between cutting process and tool geometry must be studied. In this study, relations between grinding wheel geometry, setting condition and tool geometry are revealed. For the purpose of studying relations between each parameter, the equivalent diameter of tool has been calculated assuming tool as a simple beam. By the various cutting simulations and experiments, tool geometry and cutting process has been studied.

• 한국기계기술학회지
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• 제13권3호
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• pp.31-37
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• 2011

The purpose of this study is to investigate cutting characteristics and wear behavior in SCM440 steel with different cutting tools, CBN(Cubic Boron Nitride) and coated CBN. During the test coated CBN tool especially with TiAlN showed better wear resistance behavior than orginal CBN tools. In the interrupted cutting condition, axial groove affected tool surface with impact force during the turning operation. For advantageous turning parameter in the interrupted process it is recommendable that lower speed. Also surface roughness showed better behavior in the coated CBN tool conditions than normal CBN conditions. Mainly this is caused by reduced friction between material and tool surface with coated layer.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.38-42
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• 2001

A complete quantitative understanding of DT has been difficult because the process represents such a broad field of research. The experimental measurement of tool force is a single area of DT which still covers a wide range of possibilities. There are numerous parameters of the process which affect cutting forces. There are also many turnable materials of current interest. To obtain information toward a better understanding of the process, a few cutting parameters and materials were selected for detail study. It was decided that free-oxygen copper and 6061-T6 alloy aluminum would be the primary test materials. There are materials which other workers have also used because of there wide use in reflective applications. The experimental phase of the research project began by designing tests to isolate certain cutting parameters. The parameters chosen to study were those that affected the cross-sectional area of the uncut chip. The specific parameters which cause this area to vary are the depth of cut and infeed per revolution, or feedrates. Other parameter such a tool nose radius and surface roughness were investigated as they became relevant to the research.