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Page 897 of 938 Results 8961 - 8970 of 9371

K. T. V. Grattan, J. Skeivalas, V. Giniotis
DEVELOPMENT OF 2D OPTICAL MEASUREMENTS

The analysis of 2D measurement methods and means is presented. The actual optical-electronic devices using bar codes are discussed. The correlation functions of measuring and reference codes in the electronic level instrument are calculated showing possible errors in height determination. The new electronic level design is proposed simplifying the main design and as well as the meter of the level. The principal correlation and error determination equations are given, and the diagrams of the new design are included.

Janos Kundrak, P. Herbert Osanna, Viktoria Bana, Ali Afjehi-Sadat
REALIZATION OF ACCURACY AND QUALITY REQUIREMENTS IN HARD CUTTING

Choosing out of the machining process for the finishing process of machining of the parts requires great attention because by means of that the accuracy and quality requirements prescribed for the parts must be ensured. This paper analysis two processes, the grinding and the hard turning applied for finishing machining of hardened surfaces and presents what kind of accuracy and surface quality parameters for the gears’ hardened surfaces can be ensured with hard cutting.

Ryusuke Nakajima, Takashi Miyoshi, Yasuhiro Takaya, Satoru Takahashi
INTERNAL DEFECT DETECTION IN THE VICINITY OF SI WAFER SURFACE USING EVANESCENT WAVE

In order to reduce and control yield loss in the fabrication process of next generation ULSI devices, nano-defects inspection technique for polished Silicon (Si) wafer surface becomes more essential. This paper discusses the new optical nano-defects detection method, which is applicable to the silicon wafer surface inspection technique for next-generation semiconductors.
In our proposed method, the evanescent light is emerged on the wafer surface with total internal reflection (TIR) of infrared (IR) laser at the Si-air interface. And by scanning the surface where is evanescent light emerging with very shaped fibre probe, it enables to detect nanometre scale defects in the vicinity of Si wafer surface without diffraction limit to resolution. To verify the feasibility of this method, both of the computer simulations based on Maxwell’s equations and the several fundamental experiments are performed. FDTD simulation shows that the proposed method is effective to detect nano-defects existing not only on Si surface but also in the subsurface with high sensitivity. And also the fundamental experiments show the validity of this method by demonstrating nano-defects detections of subsurface as well as surface.

A. Titov, I. Malinovsky, C.A. Massone, M. Kleinke, M.E.R. Dotto
WRINGING DEFORMATION AND ROUGHNESS ASPECTS IN OPTICAL LENGTH MEASUREMENTS

Texture deformations of gauge block surfaces arising in the wringing contact between similar structures have been determined for the first time using atomic force microscopy and optical interferometry. The level of deformations is shown to be dependent on the surface structure, and for modern gauge blocks is about 3 nm, only. Using new parallax-free methods of interferometric length measurements, roughness contribution to the measurement result by optical interferometry have been measured with a few nanometer uncertainty level.

Halina Nieciag, Zbigniew Chuchro
A CERTAIN METHOD FOR CHEBYSHEV APPROXIMATION USED IN IOS METROLOGICAL SOFTWARE

The paper presents a method that is an attempt to solve the problem of non-linear approximation of geometrical elements according to Chebyshev norm. On the base of general two step algorithm it performs an evaluation of minimal deviation from maximal values of measured shapes driving to the optimal solution on the iterative way. The proposed method implemented for some geometric features has been verified for a many samples of simulated and measured datapoints.

Dariusz Janecki, Stanislaw Adamczak
RECURSIVE GAUSSIAN FILTERS

The paper discuss the general methodology for the design of recursive digital filters with phase correction. The method for the approximation of the Gaussian characteristic presented below ensures the smallest possible error for a given filter order. It has been shown that by selecting appropriate initial values of the filter we can eliminate the so-called edge effect and evaluate the whole profile being registered. To describe the filter transfer function, the discrete incremental difference operator (delta operator) is applied in place of the usual shift operator z. This increases the accuracy of representation of filter parameters and decreases the number rounding errors.

Rogér Ernst, Albert Weckenmann, Roman Velgan
LOCAL WALL THICKNESS MEASUREMENT OF FORMED SHEET METAL USING FRINGE PROJECTION TECHNIQUE

An optical system based on fringe projection method has been developed for the measurement of the cross-section area of formed sheet metal, which is generally susceptible of being reduced, and sometimes leads to necking and tearing during forming process. A better understanding of the material and component behaviour is a challenge to experimental measuring methods. To realise such a method the part to be measured is digitised in different orientations by a fringe projection system. With the help of a newly developed inspection technique, the estimation of wall thickness in the critical zones of formed sheet metal part will be implemented by evaluating the measured data, taken in different orientations from the fringe projection system, and the result would be displayed for visualisation. This method allows fast, objective and non-destructive inspection of formed metal sheet and the detection of its defects. This measurement system can be integrated in automated operating procedure for 100% inspection and also enables the speeding up of mass production. This work presents an evaluation strategy and first measuring results.

Ryoshu Furutani, Ken Shimojima, Kiyoshi Takamasu
KINEMATICAL CALIBRATION OF ARTICULATED CMM USING MULTIPLE SIMPLE ARTIFACTS

Articulated Coordinate Measuring Machines(CMMs) are widely used to measure a large scale and/or complicated workpiece, as it is very flexible. The kinematical calibration of the articulated CMM is usually performed using some 3D artifacts. However, 3D artifact is too large and difficult to be handled. So, we tried to use a simple artifact several times and to get the equivalent calibration result to 3D artifact. In this paper, the principle of using multiple simple artifacts is presented. The kinematical calibration using some typical simple artifacts and/or the combination of those are simulated. In this simulation, the calibration, which was performed with the ball bar in four different locations and orientations, was equivalent to the calibration with 3D artifact. Finally, the experiment of calibration with the ball bar is performed.

Masanao Fujiwara, Kiyoshi Takamasu, Shigeo Ozono
EVALUATION OF PROPERTIES OF NANO-CMM BY THERMAL DRIFT AND TILT ANGLE

We have started developing novel systems and key technology as “Nano-CMM project”. In this project, our intention is developing the CMM with nano meter resolution to measure three-dimensional positions, orientations and parameters of three-dimensional features. For developing Nano-CMM, we evaluate properties of stages for Nano-CMM by thermal drift and tilt angles. In this report, the thermal drift and tilt angles of stages of Nano-CMM were evaluated. Then we made the new prototype of Nano-CMM made of low thermal expansion iron steel to reduce the influence of thermal drift and we also propose new construction of Nano-CMM for reducing the effect by tilt angles.

Zbigniew Humienny, Göran Johansson, Wlodek Kulesza
APPLICATION OF VECTORIAL DIMENSIONING AND TOLERANCING TO AN UNIQUE 3-D STACKUP ANALYSIS

It is demonstrated that a dependent dimension in assembly, indicated according to the classical dimensioning rules, is not uniquely defined. It is shown that if parts in assembly are defined by the vectorial dimensioning and tolerancing, VDT, then unique specification and verification of the analysed functional dimension in assembly is assured. The stackup of location and orientation vectors on the case of an assembly shaft– sleeve–plate based on experiments carried on coordinate measuring machine, CMM, is analysed.

Page 897 of 938 Results 8961 - 8970 of 9371