• Journal of Industrial Technology
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• v.17
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• pp.11-20
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• 1997

This paper deals with the study on the cutting characteristics in ball endmilling process. First of all, the effects of the geometric cutting conditions such as the cutting speed, feedrates and the path interval on the surface integrity were evaluated by the analytical and the experimental approaches. Secondly, the cutting mechanism model was developed to predict the cutting force accurately. Prediction of cutting force make it possible to predict the shape error, estimate system stability and build the reliable adaptive control system. A large amount of experimental set are performed to show the validities of the proposed theories and to investigate the effect of cutting geometry such as rubbing effects, burr effects and etc.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.1
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• pp.78-87
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• 2001

This paper deals with the study on the cutting characteristics in ball-end milling process. First of all, the effects of the geometric cutting conditions such as the cutting speed, feedrates and the path interval on the surface integrity were evaluat-ed by the analytical and the experimental approaches. Secondly, the cutting mechanism model was developed to predict the cutting force accurately. It is possible for the proposed model to predict the shape error, estimate system stability and build the reliable adaptive control system. A large amount of experimental set are performed to show the validities of the proposed theories and to investigate the effect of cutting geometry such as rubbing effects, burr effects and etc.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.135-140
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• 2002

Studies on the optimization of machining process can be divided into two different approaches: off-line feedrate scheduling and adaptive control. Each approach possesses its respective strong and weak points compared to each other. That is, each system can be complementary to the other. In this regard, a combined system, which is a feedrate control system for cutting force optimization, was proposed in this paper to make the best of each approach. Experimental results show that the proposed system could overcome the weak points of two systems.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.24-27
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• 1997

A periodic disturbance canceler is proposed to compensate the periodic disturbance due to cutting process in a CNC machining center. For precision cutting, the combination of a disturbance observer and a periodic disturbance canceler is desirable in order to compensate both the frictional force and the periodic disturbance. This method is implemented in a position control system of a CNC machining center in cutting process and the experimental results are described to show its effectiveness.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.195-204
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• 2001

Virtual computer numerical control(VCNC) arises from the concept that one can experience pseudo-real machining with a computer-numerically-controlled(CNC) machine before actually cutting an object. To achieve accurate VCNC, it is important to determine abnormal behavior, such as chatter, before cutting. Detecting chatter requires an understanding of the dynamic cutting force model. In general, the cutting process is a closed loop system that consists of structural and cutting dynamics. Machining instability, namely chatter, results from the interaction between these two dynamics. Several previous reports have predicted stability for a single path, using a simple cutting force model without tool runout and penetration effects. This study considers both tool runout and penetration effects, using experimental modal analysis, to obtain more accurate predictions. The machining stability in the corner cut, which is a typical transient cut, was assessed from an evaluation of the cutting configurations at the corner.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.34-39
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• 1999

If the on-line cutting conditions (e.g. speed, feedrate, radial and axal depth of cuts) can be identified in an end milling process, much information about cutting forces will be estimated from the cutting force model. Therefore, those estimated conditions can be applied to monitoring and control areas. In this paper, a real-time estimation algorithm for radial and axial depth of cuts is studied in end milling using the averaging cutting forces per tooth. The analytical estimation models of depth of cuts are derived from the geometric cutting force model. The validity of the estimation models is verified on a horizontal machining center through the experiments in various cutting conditions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.4
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• pp.271-280
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• 2016

Predicting cutting forces in machine tools is essential to productivity improvement and process control in the manufacturing field. Furthermore, milling machining is more complicated than turning machining. Therefore, several studies have been conducted previously to simulate milling forces; this study aims to simulate the cutting forces in milling machines using multi-layered neural networks. In the experiments, the number of layers in these networks was 3 and 4 and the number of neurons in the hidden layers was varied from 20 to 200. The root mean square errors of simulated cutting force components were obtained from taught and untaught data for the various neural networks. Results show that the error trends for untaught data were non-uniform because of the complex nature of the cutting force components, which was caused by different cutting factors and nonlinear characteristics coming into play. However, trends for taught data showed a very good coincidence.

• Design & Manufacturing
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• v.13 no.2
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• pp.54-59
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• 2019

CNC(Computer Numerical Control) machine tools are being used in various industrial fields such as aircraft and automobiles. The machining conditions used in the mold industry are used, and the simulation and the experiment are compared. The tool used in the experiment was carried out to increase the reliability of the simulation of the cutting machining. The program used in the 3D-FEM (finite element method) was the AdvantEdge and predicted by down-milling. The tool model is used 3D-FEM simulation by using the cutting force, temperature prediction. In this study, we carried out the verification of cutting force by using a 3-axis tool dynamometer (Kistler 9257B) system when machining the plastic mold Steel machining of NAK-80. The cutting force experiment data using on the charge amplifier (5070A) is amplified, and the 3-axis cutting force data are saved as a TDMS file using the Lab-View based program using on NI-PXIe-1062Q. The machining condition 7 was the most similar to the simulation and the experimental results. The material properties of the NAK-80 material and the simulation trends reflected in the reverse design of the tool were derived similarly to the experimental results.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.4
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• pp.93-100
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• 2002

The current from the feed motor of a machine tool contains substantial information about the machining state. There have been many researches that investigated the current as a measure for the cutting farces. However it has been reported that this indirect measurement of the cutting farces from the feed motor current is only feasible in low frequency. In this research, it was presented that the bandwidth of the current monitoring can be expanded to 130 Hz. And the unusual behavior of the current was examined in this bandwidth. The cross-feed directional cutting force influences the machined surface of the workpiece, which makes it necessary to estimate this force to control the roughness of the machined sulfate. The current exists in the stationary feed motor, and it can give the useful information on the quality of the machined surface. But the unpredictable behavior of the current prevents applying the current to prediction of the cutting state. Empirical approach was conducted to resolve the problem. As a result, the current was shown to be related to the accumulation of the accumulation of the infinitesimal rotation of the motor. rotation of the motor. Subsequently the relationship between the current and the cutting force was identified.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1480-1486
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• 2002

In this study, the cross-coupling control (CCC) with three new features is proposed to maintain contour precision in high-speed nonlinear contour machining. One is an improved contour error model that provides almost exact calculation of the errors. Another is the utilization of variable controller gains based on the instantaneous curvature of the contour and the variable command. For this scheme, a stability is analyzed. As a result, the stability region is obtained, and the variable gains are decided within that region. The other scheme in the proposed CCC is a real-time feedrate adaptation module to regulate cutting force fur better surface finish through regulation of material removal rate (MRR). The simulation results show that the proposed CCC system can provide better precision than the existing method particularly in high-speed machining of nonlinear contours.