• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.945-959
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• 1996

In this paper, a comprehensive computer model is described which can be used to generate the volumetric error map combining the machine parametric errors and the measurement prove error, for most types of CMMs and axis configurations currently in use.

• IE interfaces
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• v.15 no.4
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• pp.432-438
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• 2002

When the trailing edge and leading edge of an airfoil contour of high pressure compressor blades are measured, there exists a measurement error due to the size of the probe stylus ball diameter. In the paper an experimental study is provided to determine the optimum diameter of the probe stylus in inspecting the airfoil of the high pressure compressor blade. The measurement and analysis procedure suggested in this paper will be helpful to those who are involved in measuring and inspecting various types of blades.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.407-415
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• 1993

This report presents an automatic measurement method of 3-dimensional profiles of free-formed surfaces, by using a touch a touch-trigger contact probe along with a conventional coordinate measuring machine. The method proceeds in three steps; The surface profile under consideration is traced by the probe in an automatic manner, and then its measured data is compensated by considering the actual probe radius. Finally the compensated data is rearranged in the form suitable for the further processings of CAD/CAM applications. Some experimental results are discussed to verify the validity of the method suggested in this study.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.75-80
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• 2008

This paper presents an atomic force probe for triggering coordinate measuring machines(CMMs). A rigorous comparison is made between touch trigger probe and atomic force probe for CMMs. Typical CMMs(touch trigger probe based CMMs) often lead to some errors associated with object curvature and difference in triggering sensitivity. Their applicability is limited only to hard objects. The aim of this work is to develop a trigger sensor for CMMs using atomic force. In order to show the applicability of atomic force as a trigger sensor, a cylindrical shape is measured with a CMM and an atomic force microscope. Three different touch probe heads with different ball sizes are tested. The experiments show that smaller ball provides better results for curved objects. The experimental results also show that the performance of atomic force as a trigger sensor is about that of the smallest ball probe. In addition, experiments are also performed to measure soft objects. Finally, this paper suggests and verifies a trigger sensor using atomic force for CMMs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4
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• pp.157-165
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• 1992

IMS, a precision coordinate measuring system using theodolites, is being used to survey and align precision mechanical structures. Compared to conventional mechanical devices for precision measurement, such as CMM (Coordinate Measuring Machine), the target objects of IMS have little limitations in their sizes and shapes, and can be measured in place. Also since IMS displays the coordinate values in real-time, it is possible to perform measurement and alignment of the objects simultaneously. In this paper, the elements and functions of IMS are introduced and a mathematical model of the new software, which utilizes an altered version of the 'Bundle' adjustment algorithm of analytical photogrammetry for the specific use of IMS, is demonstrated. Differences of the mathematical model of IMS from that of analytical photogrammetry are discussed by following the steps of the 'Measurement' option in the 'Main Menu' of the software. A new IMS calibration method is proposed to calculate better first approximations for the 4 unknown theodolite parameters and the coordinates of target objects. The software provides the 'Bundle' procedure for the first approximations of the unknowns before the real-time measurement. It also provides an opportunity of 'bundling' to re-adjust the collected positional data at the end of the measurement.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.1
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• pp.60-68
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• 2004

The purpose of this paper is to establish an effective inspection system by using OMM (On-Machine Measurement) system based PC-NC. This system can reduce manufacturing lead time because a workpiece is inspected at every machining process and the manufacturing system which includes inspection faculty is able to realize on-line process on CNC machining center. The proposed OMM system is composed of a few algorithms for determination of inspection parameters. It is accomplished by determining the number of measuring points, their location, measuring path using fuzzy logic, Hammersley's method, TSP (Traveling Salesperson Problem) algorithm. The inspection feature applied to this system is based on machining feature. This method is tested by simulation and experiment that are analyzed measuring data and geometry tolerance.

• International Journal of Concrete Structures and Materials
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• v.10 no.2
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• pp.189-203
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• 2016

This paper investigates on the use of advanced optical measurement methods, i.e. 3D coordinate measurement machines (3D CMM) and stereo-vision digital image correlation (3D DIC), for the mechanical analysis of shear deficient prestressed concrete members. Firstly, the experimental program is elaborated. Secondly, the working principle, experimental setup and corresponding accuracy and precision of the considered optical measurement techniques are reported. A novel way to apply synthesised strain sensor patterns for DIC is introduced. Thirdly, the experimental results are reported and an analysis is made of the structural behaviour based on the gathered experimental data. Both techniques yielded useful and complete data in comparison to traditional mechanical measurement techniques and allowed for the assessment of the mechanical behaviour of the reported test specimens. The identified structural behaviour presented in this paper can be used to optimize design procedure for shear-critical structural concrete members.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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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.

• Journal of Multimedia Information System
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• v.2 no.3
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• pp.255-262
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• 2015

The modern manufacturing systems and technologies produce products that are more accurate day by day. This can be reached mainly by improvement the manufacturing process with at the same time restricting more and more the quality specifications and reducing the uncertainty in part. The main objective an industry becomes to lower the part's variability, since the less variability - the better is product. One of the part of this task is measuring the object's uncertainty. The main purpose of this study is to understand the application of bootstrap method for uncertainty evaluation. Bootstrap method is a collection of sample re-use techniques designed to estimate standard errors and confidence intervals. In the case study a surface of an automobile engine block - (Top view side) is measured by Coordinate Measuring Machine (CMM) and analyzed for uncertainty using Geometric Least Squares in complex with bootstrap method. The designed experiment is composed by three similar measurements (the same features in unique reference system), but with different points (5, 10, 20) concentration at each level. Then each cloud of points was independently analyzed by means of non-linear Least Squares, after estimated results have been reported. A MatLAB software tool used to generate new samples using bootstrap function. The results of the designed experiment are summarized and show that the bootstrap method provides the possibility to evaluate the uncertainty without repeating the Coordinate Measuring Machine (CMM) measurements many times, i.e. potentially can reduce the measuring time.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.7
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• pp.986-991
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• 2004

For volumetric error measurement and calibration for machine tools, manufacturing machine or coordinate measuring machine (CMM), are studied using a Ball-bar artifact. A design of the Ball-bar is suggested manufactured by Invar, which is a low thermal expansion material, and precision steel balls. The uncertainty for the artifact method is discussed. A method of the Ball-bar artifact for obtaining 3-D position errors in CMM is proposed. The method of error vector measurement is shown using the Ball-bar artifact. Finally, the volumetric error is calculated from the error vectors and it can be used for Pitch error compensation in conventional NC machine and 3-D position Error map for calibration of NC machine tools.