Featured
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Sampling issues in coordinate metrology – R. J. Hocken
Coordinate measuring machines acquire data one point at a time on the part surface being measured. These data then must be analyzed in order to produce a substitute geometry for comparison to the design intent. Algorithms are then used to analyze these data. The results obtained depends strongly upon the measuring errors, the form error…
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Co-ordinate measuring machine task-specific measurement uncertainties – NPL Good Practice guide No.130
This guide covers methods to ascertain the measurement uncertainty associated withmeasurements made on a co-ordinate measuring machine. It describes the need to take in toaccount measurement uncertainty when making measurements on co-ordinate measuringmachines. Methods for determining task-specific measurement uncertainties are covered withparticular reference to ISO 15530.
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Geometric error measurement and compensation of machines—an update – H. Schwenke et al.
For measuring machines and machine tools, geometrical accuracy is a key performance criterion. Whilenumerical compensation is well established for CMMs, it is increasingly used on machine tools inaddition to mechanical accuracy. This paper is an update on the CIRP keynote paper by Sartori and Zhangfrom 1995 [Sartori S, Zhang GX (1995) Geometric error measurement and…
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Error compensation of coordinate measuring machine – G. Zhang et al.
The methods and results are presented for applying software error compensation to a commercial three axis coordinate measuring machine. The technique incorporates compensation for geometric positioning errors and some thermal effects. Geometric error computation is based on a rigid body model of workpiece motion in the machine coordinate frame. Complete kinematic equations of the error…
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Three dimensional metrology – R. J. Hocken et al.
The article presents the results of research into the three dimensional measurement process using a classically designed measuring machine. This machine has been retrofitted with laser interferometers to provide a stable metric and is controlled by a minicomputer. Machine motions are programmable in a high level interactive language. Data links are provided to a larger…
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A Comprehensive Review on Computational Techniques for Form Error Evaluation – Vimal Kumar Pathak · Ramanpreet Singh
Abstract In industries, precise measurement of different form errors is critical and challenging for stringent geometric and dimensional control in manufactured part. These form errors have significant influence on the functional performance of an industrial product that arises due the inherent invariability in measurement techniques and manufacturing devices. Several research have been conducted for evaluation…
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A note on the three-point method for roundness measurement – B. Muralikrishnana, S. Venkatachalam, J. Raja, M. Malburg
AbstractThis technical note presents two enhancements to three-point method for roundness measurement. They enable measuring a larger bandwidthand also present a logical progression from two-point profile to three-point roundness measurement using the combined method. Simulatedprofiles with and without step variations are used to demonstrate these improvements.
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An intercomparison of roundness measurements between tenEuropean national standards laboratories – A. Sacconi*, W. Pasin
AbstractAn intercomparison of high-accuracy roundness measurements has been carried out with the participation of thenational standards laboratories of ten European countries. The circulated artefacts were a hemispherical glass standardand a steel disc. A total of eight roundness profiles were examined, two on the hemisphere and six on the disc. Theeccentricity between external and internal surfaces…
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Some theoretical aspects of error separation techniques in surface metrology- D.J.Whitehouse
There is an increasing demand for more accurate surface metrology instruments and for techniques which willallow complicated or large parts to be measured i f t situ. This report analyses existing and new multi-orientation andmultiprobe techniques and shows how they can be used to remove systematic and variable errors.
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A best fit reference line for use in partial arcs – D.J.Whitehouse
Many methods of measuring the out-of-roundness of nominally circular components or holes have been based,for convenience, upon some form of graphical assessment in which the inspector uses a pair of compasses, a rule and agood measure of subjective judgement. This has changed in recent years with the introduction of methods which can beimplemented in an…
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An investigation of reference criteria used in roundness measurement – D. G. Chetwynd et al.
Abstract The minimum zone, minimum circumscribing and maximum inscribing references (here grouped as ‘boundingreferences’) used in the measurement of roundness are investigated. Their behaviour is studied by formulating their definitions mathematically as optimization problems. The advantages of limacon references, both for accuracy under practical measurement conditions and for computational convenience, are investigated and the relationships…