• Title/Summary/Keyword: Geometric Error Measurement

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Research on a Method for the Optical Measurement of the Rifling Angle of Artillery Based on Angle Error Correction

  • Zhang, Ye;Zheng, Yang
    • Current Optics and Photonics
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    • v.4 no.6
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    • pp.500-508
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    • 2020
  • The rifling angle of artillery is an important parameter, and its determination plays a key role in the stability, hit rate, accuracy and service life of artillery. In this study, we propose an optical measurement method for the rifling angle based on angle error correction. The method is based on the principle of geometrical optics imaging, where the rifling on the inner wall of the artillery barrel is imaged on a CCD camera target surface by an optical system. When the measurement system moves in the barrel, the rifling image rotates accordingly. According to the relationship between the rotation angle of the rifling image and the travel distance of the measurement system, different types of rifling equations are established. Solving equations of the rifling angle are deduced according to the definition of the rifling angle. Furthermore, we added an angle error correction function to the method that is based on the theory of dynamic optics. This function can measure and correct the angle error caused by the posture change of the measurement system. Thus, the rifling angle measurement accuracy is effectively improved. Finally, we simulated and analyzed the influence of parameter changes of the measurement system on rifling angle measurement accuracy. The simulation results show that the rifling angle measurement method has high measurement accuracy, and the method can be applied to different types of rifling angle measurements. The method provides the theoretical basis for the development of a high-precision rifling measurement system in the future.

The OMM system for machined form and surface roughness measurement concerned with volumetric error (기계 체적오차가 고려된 가공형상-거칠기 측정 OMM 시스템)

  • 이상준;김선호;김옥현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.681-686
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    • 2000
  • Machining information such as machined form and surface roughness accuracy is an important factor for manufacturing precise parts. To this regard, OMM(On the Machine Measurement) has been issued for last several decades to alternate with CMM. In this research, measuring system consisting of a laser probe is developed for machined form and surface roughness measurement on the machine tool. The obtained machined form accuracy is compared with reference one defined in CAD model. The measured surface roughness data is compared with measured master surface beforehand. Furthermore, using the pre-defined volumetric error map approach compensates the geometric accuracy of the machine tool. The overall performance is compared with CMM, and verified the feasibility of the measurement system.

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The OMM System for Machined Form and Surface Roughness Measurement Concerned with Volumetric Error (기계 체적오차가 고려된 가공형상-거칠기 측정 OMM 시스템)

  • 이상준;김선호;김옥현
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.7
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    • pp.232-240
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    • 2000
  • Machining information such as machined form and surface roughness accuracy is an important factor for manufacturing precise parts. To this regard, OMM(On the Machine Measurement) has been issued for last several decades to alternate with CMM. In this research, measuring system consisting of a laser probe is developed for machined form and surface roughness measurement on the machine tool. The obtained machined form accuracy is compared with reference one defined in CAD model. The measured surface roughness data is compared with measured master surface beforehand. Furthermore, using the pre-defined volumetric error map approach compensates the geometric accuracy of the machine tool. The overall performance is compared with CMM, and verified the feasibility of the measurement system.

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Characteristics Analysis and Compensation of Thermal Deformation for Machine Tools with respect to Operating Conditions (작업조건에 따른 공작기계의 열변형 특성 해석 보정)

  • 이재종;최대봉;박현구;곽성조
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.4
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    • pp.70-75
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    • 2001
  • In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. 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 spindel unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball arti-fact, and five gap sensors. In order to analyze the thermal characteristics under several operating conditions, experiments performed with the touch probe unit and five gap sensors on the vertical and horizontal machining centers.

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Geometric error assessment system for linear guideway using laser-photodiodes (레이저-수광소자를 이용한 선형 이송측의 기하학적 오차측정 시스템)

  • Pahk, H.J.;Chu, C.N.;Hwang, S.W.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.5
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    • pp.180-188
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    • 1994
  • Error assessment and evaluation for machine for machine tool slides have been considered as essential tools for improving accuracy. In this paper, a computer aided measurement technique is proposed using photo pin diodes of quadrant type and laser source. In thedeveloped system, three photo diodes are mounted on a sensor mounting table, and the sensored signal is processed by specially designed signal conditioner to give fine resolution with minimum noise. A micro computer inputs the processed signal, and the geometric errors of five degree of freedoms are successfully evaluated. Pitch, roll, yaw, vertical and horizontal straightness errors are thus assessed simultaneously for a machine tool slide. Calibration techniques such as optics calibration, photo diode calibration are proposed and implemented, giving precise calibration for the measurement system. The developed system has been applied to a practical machine tool slide, and has been found as one of efficient and precise technique for machine tool slide.

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Performance Evaluation of Five-DOF Motion under Static and Dynamic Conditions of Ultra-precision Linear Stage (초정밀 직선 스테이지에서 5 자유도 운동의 정적 및 동적 성능 평가)

  • Lee, Jae-Chang;Lee, Kwang-Il;Yang, Seung-Han
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.5
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    • pp.423-430
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    • 2014
  • In this study, the five-DOF motion at ultra-precision linear stage under static and dynamic conditions are evaluated through the extending application of ISO 230-2. As the performance factors, the bi-directional accuracy and repeatability of the five-DOF motion are quantitatively evaluated with the measurement uncertainties which are determined using the standard uncertainty of equipment used in experiment. The motion under static condition are analyzed using geometric errors. The five geometric errors except the linear displacement error are measured using optimal measurement system which is designed to enhance the standard uncertainty of geometric errors. In addition, the motion under dynamic conditions are analyzed with respect to the conditions with different feed rate of the stage. The experimental results shows that the feed rate of stage has a significant effect on straightness motions.

A Study on the measurement of Table Deflection using Laser Interferometer and It's Inspection using FEA (레이저 간섭계에 의한 테이블의 처짐측정과 FEA에 의한 이의 검증)

  • 이승수
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.10a
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    • pp.204-209
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    • 1998
  • The acceleration of the performance of machine tools influences the development of the semi-conductor and optical technology as the development of NC and measurement technology. We can mention that a traction role of the acceleration for the development like that depends on the development of the measurement technics Stylus instrument method, STM, SEM, Laser interferometer method which are used for measuring the quasi-static error of machine tools. Because the measurement has been done to unload condition without considering of mechanical stiffness in the case of machining center as we measure the quasi-static error of machine tools on general studies, people who works on the spot has many problems on the data value. Therefor we will help working more accurately on the spot by measuring, analyzing, displaying the deflection of the table and support shaft when we load on the table and the support shaft of machining center using laser interferometer. Also we try to settle new conception of the measurement method and more accurate grasp of the deflection tendency by verifing the tendency of the error measured through the comparison of the simulated error using ANSYS, a common finite element analysis program, which is able to measure heat deformation, material deformation, and error resulted form this study.

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Two-Dimensional Navigation Error for Geometry of Landmark in Line-Of-Sight Measurement Based Vision Navigation System (시선각 측정기반 비전항법시스템에서 랜드마크의 기하학적 배치에 대한 2차원 항법오차)

  • Kim, Young-Sun;Ji, Hyun-Min;Hwang, Dong-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.3
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    • pp.479-484
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    • 2012
  • Geometric effect of landmarks to the navigation error is investigated in the two-dimensional line-of-sight measurement based vision navigation system. DOP is derived between line-of-sight measurement error and navigation solution error. For cases of three landmarks in an area, variations of the DOP were observed through computer simulations. Vision navigation system experiments were performed for the cases. Simulation and experimental results show that navigation solution errors have similar trend to DOP values of the simulation.