• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.90-93
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• 2003

This paper described about the ultra-precision profile measurement of aspheric surfaces using contact probing technique. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime utilizing a circle leaf spring mechanism and a capacitive-type sensor. The, contact probe is attached on the z-axis during measurement while aspheric object are supported on the diamond turning machine(DTM). The machine xz-axis motions are monitored by a set of two orthogonal plane mirror type laser interferometers. Experimental results show that the contact probing technique developed of on-machine measurement system in this investigation is capable of providing a repeatability of 10 nanometers with a $\pm$20 uncertainty of 200nmPv.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.63-69
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• 2003

This study proposes the construction of attractor simulator for cutting characteristics evaluation of non-ferrous metals. Also this paper aims to find the optimal cutting conditions of diamond turning machine by measuring surface form and roughness to perform the cutting experiment of non-ferrous metals, which are aluminum, with diamond tool. As well, according to change cutting conditions such as feed rate, cutting force and surface roughness are measured by tool dynamometer. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics. Constructed attractor in this study can be used for cutting characteristics evaluation of non-ferrous metals

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.50-56
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• 2007

This study aims to find the optimal cutting conditions, when are IR Detection device HgCdTe is machined with diamond tool of diamond turning machine. Machining technique for HgCdTe with single point diamond turning tool is reported in this paper. The main factors influencing the machined surface quality are discovered and regularities of machining process are drawn. It has been found HgCdTe has more and more important applications in the field of modern optics. The purpose of our research is to find the optimum machining conditions for ductile cutting of HgCdTe and apply the SPDT technique to the manufacturing of ultra precision optical components of brittle materials.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.5
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• pp.64-69
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• 2014

This article presents machining experiments to assess the relationship between the profile accuracy and the workpiece hardness using a natural diamond tool on an ultra-precision diamond turning machine. The study is intended to secure a corner cube prism pattern for reflective film capable of high-quality outcomes. The optical performance levels and edge images of corner cubes having various hardness levels of the copper-coated layer on a carbon steel plate are analyzed. The hardness of the workpiece has a considerable effect on the profile accuracy. The higher the hardness of the workpiece, the better the profile accuracy and the worse the edge wear of the diamond tool.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.22-26
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• 2011

The application of fast tool servo (FTS) for diamond turning has been investigated extensively. This paper focuses on the fabrication of the sinusoidal microstructure on a roller, which generated by a piezoelectric-assisted FTS. The influence of the machining parameters on the microstructure configuration was investigated. The experiment results point out that the configuration of the machined microstructure depends mainly on the spindle speed, the diameter of roller and the driving frequency of FTS. The calculation method of the microstructure dimension was reported. The turning test results show that the diamond tool can be moved up to 1kHz without any reinjected vibration in the machining and the peak-to-valley amplitude of the machined sinusoidal microstructure is about 12<${\mu}m$

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1352-1355
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• 1996

The control of diamond turning is usually achieved through a laser-interferometer feedback of slide position. If the tool post is rigid and the material removal process is relatively static, then such a non-collocated position feedback control scheme may surface. However, as the accuracy requirement gets tighter and desired surface contours become more complex, the need for a direct tool-tip sensing becomes inevitable. The physical constraints of the machining process prohibit any reasonable implementation of a tool-tip motion measurement. It is proposed that the measured force normal to the face of the workpiece can be filtered through an appropriate admittance transfer function to result in the estimated depth of cut. This can be compared to the desired depth of cut to generate the adjustment control action in addition to position feedback control. In this work, the design methodology on the admittance model-based control with a conventional controller is presented. The recursive least-squares algorithm with forgetting factor is proposed to identify the parameters and update the cutting process in real time. The normal cutting forces are measured to identify the cutting dynamics in the real diamond turning process using the precision dynamometer. Based on the parameter estimation of cutting dynamics and the admittance model-based nanodynamic control scheme, simulation results are shown.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.525-528
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• 2003

The aspherical lens are used as objective lens of optical pickup. The sample product is made before manufacturing the injection mould of lens to examine the design factor. The optimum cutting conditions of the main spindle speed, the depth of cut, the feed rate are found when we cut PMMA and PC lens sample with ultra-precision SPDT. The demanded surface roughness 10 nm Ra. aspherical form error 0.5 ${\mu}{\textrm}{m}$ P-V for aspherical lens of optical data storage device are satisfied for PMMA. but not satisfied for PC.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.391-395
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• 2002

This paper described about the ultra-precision profile measurement of aspheric surfaces using contact probing technique. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime utilizing a leaf spring mechanism and a capacitive-type sensor. The contact probe is attached on the z-axis during measurement while aspheric objects are supported on the single point diamond turning machine(SPDTM). The machine xz-axis motions are monitored by a set of two orthogonal plane mirror type laser interferometers. Experimental results show that the contact probing technique developed of On-machine Measurement System in this investigation is capable of providing a repeatability of 20 nanometers with a $\pm$20 uncertainty of 300 nanometers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.273-274
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.573-574
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• 2012