• Journal of Computational Design and Engineering
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• 제1권2호
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• pp.128-139
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• 2014

This study investigates the effects of machining parameters as they relate to the quality characteristics of machined features. Two most important quality characteristics are set as the dimensional accuracy and the surface roughness. Before any newly acquired machine tool is put to use for production, it is important to test the machine in a systematic way to find out how different parameter settings affect machining quality. The empirical verification was made by conducting a Design of Experiment (DOE) with 3 levels and 3 factors on a state-of-the-art Cincinnati Hawk Arrow 750 Vertical Machining Center (VMC). Data analysis revealed that the significant factor was the Hardness of the material and the significant interaction effect was the Hardness + Feed for dimensional accuracy, while the significant factor was Speed for surface roughness. Since the equally important thing is the capability of the instruments from which the quality characteristics are being measured, a comparison was made between the VMC touch probe readings and the measurements from a Mi-tutoyo coordinate measuring machine (CMM) on bore diameters. A machine mounted touch probe has gained a wide acceptance in recent years, as it is more suitable for the modern manufacturing environment. The data vindicated that the VMC touch probe has the capability that is suitable for the production environment. The test results can be incorporated in the process plan to help maintain the machining quality in the subsequent runs.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.73-77
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• 1997

This paper describes the analysis of measuring error of on the machine measuring(OMM) system which can directly measure the three dimensional machined free surface dimension using scanning probe on milling machine. 21 inch TV shadow mask mould was measured using PTP(point to point)measurement algorithm at pallet clamped and unclamped state on OMM system, and using coordinate measuring machine(CMM) one after another. The OMM system was evaluated probe error, stylus contact error, center shift error, repeatability and so on. Consequencely, the conclusion derived that elastic displacement of pallet had effect on measuring error mainly, and pallet design and setup method would be important.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1543-1546
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• 2005

This paper presents a method to measure a large surface shape using atomic force microscopy, which has been used mostly for measuring over very tiny surfaces. Experiments are performed to measure a step height and a slope of a test sample. The proposed method is rigorously compared with the coordinate measuring machine. The repetition accuracy and the effects of the set point are also studied. The experimental results show that the proposed method is reliable and should be effective to measure both the nano-accuracy surface profile as well as the micro-accuracy global shape of a macro/micro parts using atomic force microscope.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1991년도 추계학술대회 논문집
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• pp.116-120
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• 1991

Technique of length measurement error is widely used in the accuracy assessment of CMMS(Coordinate measuring machines) and machine tools, as it is simple and direct measurement within the working volume of a machine. In this paper, a new method is proposed for the evaluation of the length measurement error in relation to the volumetric accuracy. lD, 2D, and 3D measuring lines are considered for recpective length measurement error: 1D, 2D, and 3D length measurement uncertainties are evaluated from volumetric accuracy. The relationship between the volumetric accuracy md length measurement error to is discussed. PC based system for length measurement error evaluation and simulation is developed.

• 한국정밀공학회지
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• 제12권6호
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• pp.64-71
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• 1995

The objective of this paper is to realize an analysis system that is capable of controlling the quality of an entire cutting process by including a 3 coordinate measuring machine in the process line. Fuzzy reasoning networks based on fuzzy associative memories has been intro- duced in the measuring process, the control limits for the control process have been obtained, and the efficiency and reliability of the system have been determined by examining the simu- lated reasoning control values.

• 한국정밀공학회지
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• 제10권4호
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• pp.16-29
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• 1993

The objective of this research is in the development of a flexible 3-dimensional inspection system for the sculptured surface by integrating the Coordinate Measuring Machine (CMM), CAD database, and vision system. To achieve the proposed flexible inspection system, two research categories are discussed in the study: new inspection planning method includes a new measuring point selection method and various new probe path generation methods. The object recognition and localization process for the unknown surface can be easily carried out by introducing a new concept called "Z-Layer". The experimental results indicate that the developed flexible inspection system, with the proposed algorithm, can be inplemented in real situation.situation.

• 한국정밀공학회지
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• 제20권11호
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• pp.134-141
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• 2003

An industrial product is designed and fabricated, followed by the inspection process in order to check whether it is dimensionally tolerable or not. The machining process produces a part such as a mold or die, in which the three-dimensional coordinate might be measured by a CMM (Coordinate Measuring Machine) for assessment of its dimension. It is not ignorable, however, that a CMM measurement requires a lot of operating time and cost, which has led to many studies on the OMM system. The OMM system can be categorized into contact and non-contact types, and each of which has its own strengths and weaknesses. Non-contacting types generally utilize structured lights, sounds or magnetic fields. Though they show rather poor performance in positional accuracy, the measuring speed is faster than the contacting probes. This paper presents the development of an OMM system based on a non-contacting laser displacement sensing apparatus and CAD model. The system is composed of software modules of center-aligning and measuring, which has been operated and verified on a NC machining center on a shop floor.

• 대한토목학회논문집
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• 제12권4호
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• pp.157-165
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• 1992

데오돌라이트를 이용한 정밀측량시스템인 IMS가 개발되어 기계구조물의 정밀측량에 사용되고 있다. CMM(Coordinate Measuring Machine)과 같은 종래의 기계적 정밀측정장비에 비하여 측량대상물의 크기와 모양에 거의 제한이 없으며, 대상물이 설치되어 있는 현장에서 측량을 실시할 수 있다는 장점이 있으며, 또한 자료의 실시간 표현이 가능하여 대상물에 대한 관측과 위치수정을 동시에 수행할 수 있다는 장점도 가지고 있다. 본 논문에서는 IMS의 구성과 기능에 관한 고찰과 더불어, 새로이 개발된 소프트웨어의 수학적 모델이 제시되었는데, 그 모델은 해석사진측량에서의 광속조정법을 IMS의 특수성에 맞게 변형한 형태이다. 관측에서의 단계별 진행방법이 설명되었고, 그 배경 및 해석사진측량 기법과의 차이에 대하여 논의되었다. 데오돌라이트 외부표정요소와 대상물 공간좌표의 초기치를 더욱 근사(近似)하게 계산할 수 있는 새로운 IMS Calibration의 방법도 제시되었다. 대상물 관측전에 광속조정접을 적용하여 데오돌라이트 외부표정요소와 대상물 공간좌표의 초기치를 산출하도록 하였으며, 측량작업이 완료된 후 광속조정법을 이용하여 결과치를 재보정할 수 있게 하였다.

• Journal of Mechanical Science and Technology
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• 제19권8호
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• pp.1576-1581
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• 2005

Generally, the optical components are fabricated by grinding, lapping, and polishing. And, those processes take long time to obtain such a high surface quality. Therefore, in the case of large optical component, the on-machine inspection (OMI) is essential. Because, the work piece is fragile and difficult to set up for fabricating and measuring. This paper is concerned about a swing-arm method for measuring surface profile of large optical concave mirror. The measuring accuracy and uncertainty for suggested method are studied. The experimental results show that this method is useful specially in lapping process with the accuracy of $3\~5\;{\mu}m$. Those inspection data are provided for correcting the residual figuring error in lapping or polishing processes.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.319-325
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• 2002

Reverse Engineering is to find CAD model through measured data of a physical model which is not available in CAD model. The measured data are obtained from measuring with Coordinate Measuring Machine or Laser Scanner. This paper introduces efficient methods of reconstruction through the applicating process of the Reverse Engineering with technical surfaces.