• 대한기계학회논문집
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• 제14권6호
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• pp.1542-1551
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• 1990

본 연구에서는 직경오차를 최종 다듬질 가공 직전에 선반의 주축 정지 상태에 서 공구대에 부착시킨 전기마이크로미터로 측정하는 방법을 이용하여, 어떠한 공작물 형상에 대해서도 오차 측정경로를 NC 프로그램으로 자동 생성하고 이를 이용하여 직경 오차를 측정, 보정하는 알고리즘을 제안함과 동시에 수정된 최종 다듬질 가공용 NC프 로그램을 자동적으로 생성하는 시스템을 개발하고자 한다.

• 소성∙가공
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• 제16권1호
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• pp.15-19
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• 2007

This paper presents an integrated machining error compensation method based on captured images of tool deflection shapes in flat end-milling processes. This approach allows us to avoid modeling machining characteristics (cutting forces, tool deflections and machining errors etc.) and accumulating calculation errors induced by several simulations. For this, a high-speed camera captured images of real deformed tool shapes which were cutting under given machining conditions. Using image processes and a machining error model, it is possible to estimate tool deflection in cutting conditions modeled and to compensate for machining errors using an iterative algorithm correcting tool paths. This corrected tool path can effectively reduce machining errors in the flat end-milling process. Experiments are carried out to validate the approaches proposed in this paper. The proposed error compensation method can be effectively implemented in a real machining situation, producing much smaller errors.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.917-921
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• 2000

One of the major limitations of productivity and quality in machining is machining accuracy of the machine tools. The machining accuracy is affected by geometric, volumetric errors of the machine tools. This paper suggests the enhancement method of machining accuracy for precision machining of high quality metal reflection mirror or optics lens, etc. In this paper, we study 1) the compensation of linear pitch error with NC controller compensation function using laser interferometer measurement, 2) the method for enhancing the accuracy of NC milling machining by modeling and compensation of volumetric error, 3) the generation of the parabolic face profile. And the method is verified by the parabolic face machining experiment with a vertical three axes NC milling machine. After this study, we will inspect using On-machine measurement and study the repetitive machining by a compensated path

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.417-422
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• 2002

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric errors, thermally-induced errors, and the deterioration of the machine tools. Geometric and thermal errors of machine tools should be measured and compensated to manufacture high quality products. In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. In this study, the compensation device and temperature-based algorithm have been implemented on the machining center in order to compensate thermal error of machine tools under the real-time. The thermal errors are predicted using the neural network and multi-regression modeling methods. In order to compensate thermal characteristics under several operating conditions, experiments performed with five gap sensors and manufactured compensation device on the horizontal machining center.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.214-219
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• 2001

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric errors, thermally-induced errors, and the deterioration of the machine tools. Geometric and thermal errors of machine tools should be measured and compensated to manufacture high quality products. In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. In this study, the compensation device and temperature-based algorithm have been presented in order to compensate thermal error of machine tools under the real-time. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball artifact, and five gap sensors. In order to compensate thermal characteristics under several operating conditions, experiments performed with five gap sensors and manufactured compensation device on the horizontal machining center.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.453-457
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• 2001

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric and thermal errors of the machine tools. In this study, the compensation device is manufactured in order to compensate thermal error of machine tools under the real-time. This paper models of the thermal errors for error analysis and develops on-the-machine measurement system by which the volumetric error are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball artifact, and five gap sensors. In order to compensate thermal characteristics under several operating conditions, experiments performed with five gap sensors and manufactured compensation device on the horizontal machining center.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1352-1357
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• 2004

Thermal error compensation has been developed for CNC (Computer Numerical Control) machining center with moving heat sources. The thermal error in CNC machining center has an effect on machining accuracy more than the geometric error does. Thus, temperature distributions of a spindle unit have been analyzed numerically by a Finite Differential Method and experimentally by an infrared (IR) camera in this study. A multiple variable method has been derived to estimate the thermal deformation of the machine origin stably and effectively after measuring deformation and temperature data. The experimental results for a vertical machining center have shown that the thermal errors of the machine origins were reduced more than 30% by the developed method.

• 한국융합학회논문지
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• 제8권5호
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• pp.185-192
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• 2017

공작기계의 오차는 크게 기하하적 오차, 열변형 오차 및 가공오차로 나눌 수 있다. 본 연구에서는 2차원 가공에서, 각 오차의 원인이 전체 오차에 미치는 영향과 각 오차의 상대적 크기를 정량적으로 분석하였다. 오차의 상대적 크기는 열변형 오차와 가공오차가 상대적으로 기하학적 오차에 비해 크게 나타났으며, 이는 가공 정밀도에 직접적으로 관계된다고 판단되었다. 세 가지 오차를 제거하기 위해 측정된 오차 프로파일을 이용하여 오차의 보정가능성을 검토하였다. 그 결과 각각의 오차요인에 대하여 약 50%의 시스템 오차를 보정할 수 있었으며, 특히, 열변형 오차와 가공오차의 경우 큰 폭으로 오차를 보정할 수 있음을 확인하였다. 본 연구를 통하여 가공에 관한 기본적인 데이터 베이스를 구축할 수 있으며, 이를 통해 사용자 관점에서 가공오차에 대한 보정이 가능할 것으로 기대된다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.376-381
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• 2001

This paper presents a methodology of machining error compensation by using Artificial Neural Network(ANN) model based on the inspection database of On-Machine-Measurement(OMM) system. First, the geometric errors of the machining center and the probing errors are significantly reduced through compensation processes. Then, we acquire machining error distributions from a specimen workpiece. In order to efficiently analyze the machining errors, we define two characteristic machining error parameters. These can be modeled by using an ANN model, which allows us to determine the machining errors in the domain of considered cutting conditions. Based on this ANN model, we try to correct the tool path in order to effectively reduce the errors by using an iterative algorithm. The iterative algorithm allows us to integrate changes of the cutting conditions according to the corrected tool path. Experimentation is carried out in order to validate the approaches proposed in this paper.

• 한국공작기계학회논문집
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• 제15권4호
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• pp.92-97
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• 2006

This paper presents an integrated machining error compensation method based on PNN(Polynomial Neural Network) approach and inspection database of OMM(On-Machine-Measurement) system. To efficiently analyze the machining errors, two machining error parameters are defined and modeled using the PNN approach, which is used to determine machining errors for the considered cutting conditions. Experiments are carried out to validate the approaches proposed in this paper. In result, the proposed methods can be effectively implemented in a real machining situation, producing much fewer errors.