scholarly journals Influence of the probing definition on the flatness measurement

2018 ◽  
Vol 9 ◽  
pp. 15 ◽  
Author(s):  
Djezouli Moulai-khatir ◽  
Eric Pairel ◽  
Hugues Favreliere
Keyword(s):  
Coordinate Measuring Machine ◽  
Minimum Volume ◽  
Analysis Study ◽  
Mechanical Parts ◽  
Minimum Zone ◽  
Cloud Points ◽  
Measuring Machine ◽  
Flatness Defect ◽  
Cloud Of Points ◽  
Flatness Measurement

The quality control of mechanical parts is generally performed on a coordinate measuring machine (CMM). The choice of the number of points to be sampled, their distributions and their positions on the surface, as well as the association criterion remains unresolved. This paper studies the variation of the flatness defect with regard to the number of palpated points. The methodology begins by sampling a cloud of points on a CMM. Then, a modal analysis study is carried out in order to generate a modal surfaces (digitally deformed). Insertion of the coordinate cloud points of these modal surfaces in the GEOVERIF software will allow estimation of the flatness defect. The results of the measured flatness by the three fitting criteria (minimum zone, least squares and minimum volume) are compared.

A New Procedure for Determining Minimum Sampling Points for Tolerance Evaluation of High Precision Mechanical Parts

2017 ◽  
Vol 749 ◽  
pp. 191-196
Author(s):  
Siriluk Phankhoksoong ◽  
Anchasa Pramuanjaroenkij ◽  
Tawee Ngamvilaikorn ◽  
Chatchapol Chungchoo
Keyword(s):  
High Precision ◽  
Test Piece ◽  
Performance Testing ◽  
Coordinate Measuring Machine ◽  
Sampling Point ◽  
Cnc Milling ◽  
Mechanical Parts ◽  
Cnc Milling Machine ◽  
Measuring Machine ◽  
Major Equipment

In geometric and dimension tolerance investigations, especially for high precision mechanical parts, the accuracy of measurement is very important. The major equipment for the measurement is the coordinate measuring machine (CMM). However, the recommended strategies for evaluating tolerance values of geometric and dimension cannot be applied with high precision mechanical parts. Hence, in this research, the researcher introduced a new procedure that could evaluate geometric and dimension tolerance values of high precision mechanical parts accurately. This new procedure can determine the minimum sampling point for evaluating geometric and dimension tolerance values by using some performance information on the mechanical parts of the machine. This information was the waviness of the production machine’s motion. In order to evaluate the potential of new procedure, the flatness of test piece was made according to the ISO 10791-7-A160 standard as a case study. This test piece was made from the CNC milling machine (Chevalier 2040 VMC), and the waviness of the CNC milling machine’s motion was counted from the performance testing result measured by the double ball-bar model Renishaw QC10. By comparing flatness obtained by recommended and new procedures, experimental results indicated that the new procedure showed its potential in estimating the flatness.

Reverse Engineering Approach for Object with Free-Form Surfaces Using Standard Surface-Solid Parametric CAD System

2009 ◽  
Vol 147-149 ◽  
pp. 706-711 ◽  
Author(s):  
Andrzej Łukaszewicz ◽  
Kanstantsin Miatliuk
Keyword(s):  
Coordinate Measuring Machine ◽  
Free Form ◽  
Cad System ◽  
Solid Models ◽  
Middle Range ◽  
Feature Based ◽  
Measuring Machine ◽  
Cloud Of Points ◽  
Free Form Surfaces ◽  
Modelling Process

In this paper the reverse modelling process for mapping and reconstructing the geometric characteristics of element with free-form surfaces as virtual CAD model is described. The basic approach in reverse modelling process in middle range standard parametric 3D modeler such as SolidWorks system is presented. The digitizing process was performed on the coordinate measuring machine. Using surface-solid modelling tools the virtual solid models were created. They are based on prepareing 3D curves from cloud of points as a sectional profiles. As the next step, it is possible to realize various CAx applications based on 3D feature-based model. In our case an abrasive wear of rotor blade was estimated.

scholarly journals Estimation of minimum volume of bounding box for geometrical metrology

2020 ◽  
Vol 11 ◽  
pp. 9
Author(s):  
Petr Chelishchev ◽  
Knut Sørby
Keyword(s):  
Convex Polyhedron ◽  
Three Dimensional ◽  
Computation Time ◽  
Coordinate Measuring Machine ◽  
3D Models ◽  
High Accuracy ◽  
Minimum Volume ◽  
Data Set ◽  
Bounding Box ◽  
Measuring Machine

This paper presents algorithms for estimating the minimum volume bounding box based on a three-dimensional point set measured by a coordinate measuring machine. A new algorithm, which calculates the minimum volume with high accuracy and reduced number of computations, is developed. The algorithm is based on the convex hull operation and established theories about a minimum bounding box circumscribing a convex polyhedron. The new algorithm includes a pre-processing operation that removes convex polyhedron faces located near the edges of the measured object. As showed in the paper, the solution of the minimum bonding box is not based on faces located near the edges; therefore, we can save computation time by excluding them from the convex polyhedron data set. The algorithms have been demonstrated on physical objects measured by a coordinate measuring machine, and on theoretical 3D models. The results show that the algorithm can be used when high accuracy is required, for example in calibration of reference standards.

scholarly journals Number of Points for Roundness Measurement - Measured Results Comparison

2011 ◽  
Vol 19 (30) ◽  
pp. 19-24
Author(s):  
Augustín Görög
Keyword(s):  
Least Squares ◽  
Coordinate Measuring Machine ◽  
Experimental Results ◽  
Cylindrical Grinding ◽  
Minimum Zone ◽  
Measuring Machine ◽  
Roundness Measurement

Number of Points for Roundness Measurement - Measured Results Comparison Paper deals with filtering roundness. It presents experimental results measured for roundness turning and cylindrical grinding. Roundness was measured using Prismo Navigator 5 coordinate measuring machine. Evaluation was done by four methods: Minimum zone reference circles (MZCI), Least squares reference circle (LSCI), Minimum circumscribed reference circle (MCCI) and Maximum inscribed reference circle (MICI). The filters used were: Gauss, Spline and no filter.

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