scholarly journals Performance Investigation of CMM Measurement Quality Using Flick Standard

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Salah H. R. Ali
Keyword(s):  
Measurement Errors ◽  
Coordinate Measuring Machine ◽  
Scanning Speed ◽  
Data Sets ◽  
Evaluation Tool ◽  
Roundness Error ◽  
Application Range ◽  
Evaluation Algorithm ◽  
Measuring Machine ◽  
High Level

Quality of coordinate measuring machine (CMM) in dimension and form metrology is designed and performed at the NIS. The experimental investigation of CMM performance is developed by using reference Flick standard. The measurement errors of corresponding geometric evaluation algorithm (LSQ, ME, MC, and MI) and probe scanning speed (1, 2, 3, 4, and 5 mm/s) are obtained through repeated arrangement, comparison, and judgment. The experimental results show that the roundness error deviation can be evaluated effectively and exactly for CMM performance by using Flick standard. Some of influencing quantities for diameter and roundness form errors may dominate the results at all fitting algorithms under certain circumstances. It can be shown that the 2 mm/s probe speed gives smaller roundness error than 1, 3, 4, and 5 mm/s within 0.2 : 0.3 μm. It ensures that measurement at 2 mm/s is the best case to satisfy the high level of accuracy in the certain condition. Using Flick standard as a quality evaluation tool noted a high precision incremental in diameter and roundness form indication. This means a better transfer stability of CMM quality could be significantly improved. Moreover, some error formulae of data sets have been postulated to correlate the diameter and roundness measurements within the application range. Uncertainty resulting from CMM and environmental temperature has been evaluated and confirmed the quality degree of confidence in the proposed performance investigation.

Surface Texture Measurement with Profile Method Using Six-Axis Coordinate Measuring Machine

2021 ◽  
Vol 410 ◽  
pp. 872-877
Author(s):  
Andrey V. Kochetkov ◽  
Andrey A. Troshin ◽  
Oleg V. Zakharov
Keyword(s):  
Surface Texture ◽  
Measurement Errors ◽  
Coordinate Measuring Machine ◽  
Texture Measurement ◽  
Analytical Geometry ◽  
Complex Shapes ◽  
Measurement Results ◽  
Measuring Machine ◽  
Cartesian Coordinate ◽  
Filtering Effect

Currently the measurement of surface texture in mechanical engineering is traditionally carried out using profilometers. Modern profilometers do not allow measuring of surfaces with complex shapes. This is due to the different sensitivity of the sensor and the discreteness of the movements along the axes of the Cartesian coordinate system. Coordinate Measuring Machines are devoid of such a drawback. However, stylus of the coordinate measuring machine has a diameter many times larger than the diamond stylus of the profilometer. Therefore, there is a mechanical filtering effect, that affects the results of measuring the parameters of the surface texture. In this paper a mathematical model of the contact of the spherical stylus and a rough surface based on analytical geometry is proposed. Influence of the diameter of the spherical stylus on the maximum measurement errors of a amplitude parameters are investigated. Seven amplitude parameters Rp, Rv, Rz, Ra, Rq, Rsk, Rku of the surface texture are modeled. Coordinate measuring machine and profilometer with stylus diameter of 2 μm measurement results are compared. it was concluded that the stylus diameter of the coordinate measuring machine when measuring the surface texture should be no more than 20 μm.

Towards Combining Digitization Techniques in the Generation of Reverse Engineering Data Sets

1999 ◽  
Author(s):  
C. J. Rolls ◽  
W. ElMaraghy ◽  
H. ElMaraghy
Keyword(s):  
Reverse Engineering ◽  
Computer Aided Design ◽  
Laser Scanning ◽  
Single Point ◽  
Laser Scanner ◽  
Coordinate Measuring Machine ◽  
Industrial Applications ◽  
Data Sets ◽  
Error Characterization ◽  
Measuring Machine

Abstract Reverse engineering (RE), may be defined as the process of generating computer aided design models (CAD) from existing or prototype parts. The process has been used for many years in industry. It has markedly increased in implementation in the past few years, primarily due to the introduction of rapid part digitization technologies. Current industrial applications include CAD model construction from artisan geometry, such as in automotive body styling, the generation of custom fits to human surfaces, and quality control. This paper summarizes the principles of operation behind many commercially available part digitization technologies, and discusses techniques involved in part digitization using a coordinate measuring machine (CMM) and laser scanner. An overall error characterization of the laser scanning digitization process is presented for a particular scanner. This is followed by a discussion of the merits and considerations involved in generating combined data sets with characteristics indicative of the design intent of specific part features. Issues in facilitating the assembly, or registration, of the different types of data into a single point set are discussed.

scholarly journals Accuracy of three-dimensional photogrammetry and cone beam computed tomography based on linear measurements in patients with facial deformities

2020 ◽  
pp. 20200001
Author(s):  
Zhenqi Zhao ◽  
Lizhe Xie ◽  
Dan Cao ◽  
Iman Izadikhah ◽  
Pengcheng Gao ◽  
...  
Keyword(s):  
Reference Values ◽  
Measurement Errors ◽  
Three Dimensional ◽  
Coordinate Measuring Machine ◽  
Cone Beam ◽  
Reference Systems ◽  
Linear Measurements ◽  
3D Photogrammetry ◽  
Measuring Machine ◽  
Linear Accuracy

Objectives: This study was aimed to investigate the accuracy of soft-tissue measurements obtained by two imaging modalities, three-dimensional (3D) photogrammetry and cone beam CT (CBCT) when confounded by influence factors (facial deformities and partitions). Methods: 60 wax facial models from facially deformed patients were captured by 3D photogrammetry and CBCT. 19 linear distances on each image were measured and juxtaposed to reference values attained via a coordinate-measuring machine (CMM) as the gold-standard. Paired t-tests were used to compare linear accuracy of the test and reference systems. The influence of deformities and partitions (created by dividing the face with three vertical and five horizontal lines) on the measurement errors were analyzed by independent sample t-test and one-way ANOVA. Results: Statistically significant differences were found between linear accuracy of the test and reference systems. The test values obtained by 3D photogrammetry were closer to the reference values than CBCT’s. 3D photogrammetry’s measurement errors were significantly higher in deformed areas, unlike CBCT’s. Both systems reported significantly lower errors within partitions 8 and 13 compared to other partitions; for CBCT, aside from partitions 8 and 13, the differences in the errors for partitions 6 and 10 were significant compared to partitions 8, 12, 13, 14. Conclusion: 3D photogrammetry showed a higher linear accuracy than CBCT in patients with facial deformities due to protuberances. Facial reconstruction by both test modalities was significantly influenced in different facial partitions, but facial deformities extensively affected the results from 3D photogrammetry.

CMM Measurement Uncertainty Reduction via Sampling Strategy Optimization

2008 ◽  
Author(s):  
Giovanni Moroni ◽  
Stefano Petro`
Keyword(s):  
Measurement Uncertainty ◽  
Measurement Errors ◽  
Coordinate Measuring Machine ◽  
Sampling Strategy ◽  
Uncertainty Reduction ◽  
Repeated Measurements ◽  
Trade Off ◽  
Geometrical Error ◽  
Measuring Machine

Uncertainty is a key concept in any environment which involves measurements to ensure process quality: a trade-off has to be found between measurement costs, which increase as uncertainty lowers, and costs related to measurement errors. In mechanics, geometrical conformance is a common requirement. Two similar standards series deal with the problem of uncertainty in geometrical error estimate: ASME B89.7.3 and ISO 14253. Geometrical inspection is often performed by means of a “Coordinate Measuring Machine” (CMM). For a CMM, a trade off between measurement and errors costs may be found by optimizing the sampling strategy. In this work a cost function will be proposed as support for finding a trade-off between measurement uncertainty and costs. This function may be optimized by means of an heuristic algorithm. The method will involve repeated measurements of calibrated parts to evaluate uncertainty (like in ISO/TS 15330-3). A case study will be proposed.

An Efficient Algorithm for Accurate Evaluation of Circularity Tolerance

1996 ◽  
Author(s):  
Sam Anand ◽  
Sridhar Jaganathan ◽  
Sampath Damodarasamy
Keyword(s):  
Least Squares Method ◽  
Search Algorithm ◽  
Circle Method ◽  
Extreme Points ◽  
Coordinate Measuring Machine ◽  
Data Sets ◽  
Diagram Method ◽  
Data Points ◽  
Measuring Machine ◽  
Concentric Circles

Abstract This paper presents a new and accurate algorithm for assessing circularity tolerance from a set of data points obtained from a Coordinate Measuring Machine (CMM). This method, called Selective Zone Search algorithm, divides the workspace into small sectors called search zones and searches for the extreme points in these zones. These extreme points are used to draw a pair of concentric circles with minimum radial separation. The radial difference gives the circularity. The methodology has been tested with several example data sets and the results have been compared with the Least Squares method, Minimum Spanning Circle method and the Voronoi Diagram method.

scholarly journals An investigation of Outlier Detection Procedures for CMM Measurement Data

2018 ◽  
Vol 220 ◽  
pp. 04002 ◽  
Author(s):  
Petr Chelishchev ◽  
Aleksandr Popov ◽  
Knut Sørby
Keyword(s):  
Outlier Detection ◽  
Cross Sections ◽  
Experimental Verification ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Data Sets ◽  
Dimensional Measurement ◽  
Measuring Machine ◽  
Simulation Results

The paper analyses methods for outlier detection in dimensional measurement. The cross sections of an internal cylinder were inspected by CMM (coordinate measuring machine), and received data sets were employed for further investigation. The efficiency of Rosner’s and Grubbs’ methods for excluding outliers from the measuring data had been estimated. The method of Rosner had been defined as the most effective for this case study. The simulation results were confirmed by experimental verification.

scholarly journals Effect of Scanning Speed on the Accuracy of Measu-Red Values using Coordinate Measuring Machine

2013 ◽  
Vol 10 (2) ◽  
pp. 2-5 ◽  
Author(s):  
Zdenko Guniš ◽  
Juraj Vagovský ◽  
Augustín Görög
Keyword(s):  
Experimental Work ◽  
Coordinate Measuring Machine ◽  
Scanning Speed ◽  
Measuring Machine

Abstract This paper is aimed to determine the effect of scanning speed on the coordinate measuring machine to the accuracy of the measured values. Experimental work focuses to measuring the circular sample with a prescribed diameter dimension on the coordinate measuring machine with a defined various scanning speed, and to detecting deviations of the measured values from conventional values of diameter of the circular sample. Detection of the interval of scanning speed where measured values were the closest to the conventional value of diameter of circular sample is the importance of this paper.

scholarly journals MAXIMUM- INSCRIBED AND MINIMUM-CIRCUMSCRIBED FITTING FOR CO-ORDINATE MEASURING MACHINE

2010 ◽  
Vol 13 (3) ◽  
pp. 5-13
Author(s):  
Ha Thi Thu Thai ◽  
Phuoc Hong Nguyen
Keyword(s):  
Least Squares ◽  
Simulated Annealing Algorithm ◽  
Least Squares Method ◽  
Coordinate Measuring Machine ◽  
Data Sets ◽  
Effective Algorithm ◽  
Least Squares Fit ◽  
Measuring Machine ◽  
Annealing Algorithm ◽  
Near Future

This paper describes algorithms that fit geometric shapes to data sets according to maximum- inscribed (MI) and minimum- circumscribed (MC) fit. We use these fits to build the CMM’s (Coordinate Measuring Machine) software in cases of circle, sphere and cylinder. For each case, we obtain the fit by two methods: first, by (relative easy) least squares fit method and then refine by MI and MC fit method. Although, the later method is substantially more complicated than the former one, Its results are used to make comparision with the the results of least squares method in order to give more options in the CMM software. In the near future we will continue to develop MI and MC fit with an effective algorithm- Simulated Annealing algorithm.

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