scholarly journals Assessment of Background Illumination Influence on Accuracy of Measurements Performed on Optical Coordinate Measuring Machine Equipped with Video Probe

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2509
Author(s):  
Wiktor Harmatys ◽  
Adam Gąska ◽  
Piotr Gąska ◽  
Maciej Gruza ◽  
Jerzy A. Sładek
Keyword(s):  
Coordinate Measuring Machine ◽  
Optical Systems ◽  
Diameter Measurement ◽  
Background Illumination ◽  
Multisensor Systems ◽  
Accuracy Of Measurements ◽  
Uncertainty Of Measurements ◽  
Measuring Machine ◽  
New Challenges

Currently the Coordinate Measuring Technique is facing new challenges both in terms of used methodology and a speed of measurement. More and more often modern optical systems or multisensor systems replace classic solutions. Measurement performed using the optical system is more vulnerable to incorrect points acquisition due to such factors as an inadequate focus or parameters of applied illumination. This article examines the effect of an increasing illumination on the measurement result. A glass reference plate with marked circles and a hole plate standard were used for the measurements performed on a multi-sensor machine Zeiss O’ Inspect 442. The experiment consisted of measurements of standard objects with different values of the backlight at the maximum magnification. Such approach allows to assess the influence of controlled parameter on errors of diameter and form measurements as well as an uncertainty of measurements by determination of ellipses of point repeatability. The analysis of the obtained results shows that increasing backlight mainly affects the result of the diameter measurement.

Evaluation of Actual Geometric Tolerances Using Coordinate Measuring Machine Data

1989 ◽  
Author(s):  
W. H. ElMaraghy ◽  
Z. Wu ◽  
H. A. ElMaraghy
Keyword(s):  
Three Dimensional ◽  
Measurement Data ◽  
Simulated Data ◽  
Coordinate Measuring Machine ◽  
Optimization Techniques ◽  
Test Cases ◽  
Tolerance Zone ◽  
Geometric Tolerances ◽  
Measuring Machine

Abstract This paper focuses on the development of a procedure and algorithms for the systematic comparison of geometric variations of measured features with their specified geometric tolerances. To automate the inspection of mechanical parts, it is necessary to analyze the measurement data captured by coordinate measuring machines (CMM) in order to detect out-of-tolerance conditions. A procedure for determining the geometric tolerances from the measured three dimensional coordinates on the surface of a cylindrical feature is presented. This procedure follows the definitions of the geometric tolerances used in the current Standards, and is capable of determining the value of each geometric tolerance from the composite 3-D data. The developed algorithms adopt the minimum tolerance zone criterion. Nonlinear numerical optimization techniques are used to fit the data to the minimum tolerance zone. Two test cases are given in the paper which demonstrate the successful determination of geometric tolerances from given simulated data.

Methodology for evaluate the form deviations for formula one nose car

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Paul Bere ◽  
Calin Neamtu
Keyword(s):  
Composite Material ◽  
Laser Scanning ◽  
Coordinate Measuring Machine ◽  
3D Scanning ◽  
Cad Model ◽  
3D Laser Scanning ◽  
Formula One ◽  
Dimensional Deviation ◽  
Measuring Machine

AbstractThe paper presents a measuring strategy for a Formula One car using a Coordinate Measuring Machine (CMM) and a 3D laser scanning devices. The measurement procedures outlined the dimensional deviation of the CAD model and prototype made of composite material. The authors present two methods for the determination of symmetry for components of a Formula One car based on measuring and 3D scanning.

Accuracy distribution and determination of the flexible three-coordinate measuring machine

2006 ◽  
Author(s):  
Chunhua Wang ◽  
Yetai Fei ◽  
Penghao Hu ◽  
Pingping Wang ◽  
Wentao Chen
Keyword(s):  
Coordinate Measuring Machine ◽  
Measuring Machine

Reduce Positioning Error for Robot Manipulator with Intelligent Technique

2011 ◽  
Vol 403-408 ◽  
pp. 697-706
Author(s):  
Maryam Barati ◽  
Ahmad Reza Khoogar ◽  
Mehrzad Nasiriyan
Keyword(s):  
Robot Manipulator ◽  
Coordinate Measuring Machine ◽  
Least Square ◽  
Robot Kinematics ◽  
Automatic Calibration ◽  
Intelligent Technique ◽  
Measuring Machine ◽  
Three Degree Of Freedom ◽  
Kinematics Parameters

Using robot manipulators for high accuracy applications require precise value of the kinematics parameters. Since measurement of kinematics parameters are usually corrupted with errors and their accurate measurements are usually expensive, automatic calibration of robot link parameters makes the determination of kinematic parameters much simpler. In this paper a simple and easy to use algorithm is introduced for correction and calibration of robot kinematics parameters. Actually, at several end-effecter positions, the corresponding joint variables are measured simultaneously. This information is then used in three different algorithms; the Least Square (LS), the Particle Swarm Optimization (PSO) and the Genetic algorithms (GA) for automatic calibration and correction of the kinematics parameters. This process was also tested experimentally using a three degree of freedom manipulator which was actually built as a coordinate measuring machine (CMM). The experimental Results show that the intelligent algorithms provide better results for both parameter identification and calibration of the link parameters.

Precision Analysis of Optical 3D Digitisation of Shaped Elements

2014 ◽  
Vol 693 ◽  
pp. 177-182
Author(s):  
Radomír Mendřický
Keyword(s):  
Coordinate Measuring Machine ◽  
Measurement Precision ◽  
Optical Systems ◽  
Precision Analysis ◽  
Nominal Size ◽  
Shape Precision ◽  
3D Scanners ◽  
Measuring Machine ◽  
Measured Element ◽  
3D Digitisation

This paper presents results of a carried out research in the field of scanning precision of contactless optical 3D scanners. Results stated in this paper bring great benefits to practice, since it demonstrates the quality and limits of measuring by means of contactless optical systems in real conditions and therefore its possible use in the field of inspecting the dimensional and shape precision of industrial products.A measurement etalon of various shapes and sizes was designed and manufactured for the purpose of this analysis. The nominal dimensions of the etalon were set by measuring of the coordinate measuring machine and these real values were compared to the model obtained by optical digitisation of Atos II and RevScan. Based on the evaluation of results, scanner measurement precision diagrams were drawn according to the studied aspects, e.g. dependence on the shape of the measured element and its nominal size. Another essential part of the research was determining the ability of 3D scanners to capture detailed parts of the model and assessing the scanning limits for each of the optical systems.

scholarly journals Coordinate Measuring Machine Probes Effect during Inner Thread Position Measurement

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 55
Author(s):  
Ferencz Peti ◽  
Petru Serban
Keyword(s):  
Coordinate Measuring Machine ◽  
New Method ◽  
Coordinate Measuring Machines ◽  
Position Measurement ◽  
Measurement Strategy ◽  
Accuracy Of Measurements ◽  
Measuring Machine

Starting from the idea of improving Coordinate Measuring Machines’ (CMM) measurement strategy for inner thread locations, we developed a new method which increases the accuracy of measurements and takes us closer to the pitch diameter. This article will analyze this new method by testing different touching probes configurations for different thread sizes. The objective is to identify the best probe configuration to be used in the measurements of different inner thread sizes.

The influence of a number of points on results of measurements of a turbine blade

2017 ◽  
Vol 89 (6) ◽  
pp. 953-959 ◽  
Author(s):  
Marek Magdziak
Keyword(s):  
Turbine Blades ◽  
Measuring System ◽  
Free Form ◽  
Experimental Investigations ◽  
Content Type ◽  
Measurement Strategy ◽  
Accuracy Of Measurements ◽  
Uncertainty Of Measurements ◽  
Measuring Machine ◽  
Free Form Surfaces

Purpose The purpose of this paper was to determine the influence of a number of measured points on results of measurements of turbine blades, which are the parts of aircraft engines. The selection of a number of points is the part of a measurement strategy in the coordinate measuring technique and determines the accuracy of measurements. Design/methodology/approach Numerical and experimental investigations were conducted. The measurements were simulated using different numbers of measured points. The simulated measurements were performed for the selected dispersion of measured points. The dispersion reflected the inaccuracy of a manufacturing process of the considered product and the uncertainty of measurements of curvilinear surfaces. To verify the accuracy of the numerical studies, experimental research was conducted. The real measurements were conducted using the selected coordinate measuring machine. Findings The gained results following the simulations can be very useful when selecting the appropriate number of measured points. The chosen number of points may be used during real measurements of turbine blades conducted on coordinate measuring machines. The results of numerical research indicate that there should be used the average radii of leading and trailing edges to increase the accuracy of measurements. The results of real coordinate measurements confirmed the results of simulation studies. Originality/value The main novelty of the paper is the presented methodology for determining the influence of measured points on results of measurements. The presented methodology helps the user of a coordinate measuring system select the appropriate measurement strategy of free-form surfaces applied in the aerospace industry.

Determination of True Dimensional Quality and Build Errors Using Coordinate Measurement Data

1999 ◽  
Vol 121 (4) ◽  
pp. 749-755 ◽  
Author(s):  
R. J. Gu ◽  
G. C. Barber
Keyword(s):  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Coordinate Frame ◽  
Numerical Examples ◽  
Coordinate Measurement ◽  
Acceptable Quality ◽  
Measuring Machine ◽  
Material Points

For manufacturing personnel there exist two major tasks: determination of the quality of the build, and locating build errors if the quality is inferior. To serve this purpose a coordinate measuring machine is employed to determine the actual locations of designated material points. Depending on the measuring coordinate frame chosen, the initial raw data, unfortunately, do not impartially represent the true deviations of all the measurement points. This paper shows a technique to overcome this inevitable drawback embedded in the CMMs and determine if the build has acceptable quality under specified tolerances. Also presented in this paper is a method to quantify the quality of the measurement points for easy identification of build errors. Numerical examples are given to demonstrate the feasibility of the technique.

scholarly journals Selection of the Best Model of Distribution of Measurement Points in Contact Coordinate Measurements of Free-Form Surfaces of Products

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5346 ◽  
Author(s):  
Marek Magdziak
Keyword(s):  
Coordinate Measuring Machine ◽  
New Method ◽  
Free Form ◽  
Experimental Investigations ◽  
Accuracy Of Measurements ◽  
Measuring Machine ◽  
Coordinate Measurements ◽  
Free Form Surface ◽  
Free Form Surfaces ◽  
Selection Of

The article presents a new method for determining the distribution of measurement points, which can be used in the case of contact coordinate measurements of curvilinear surfaces of products. The developed method is based on multi-criteria decision analysis. In the case of the new method, the selection of the distribution of measurement points on free-form surfaces is carried out based on the analysis of five different criteria. The selection of the best model of the distribution of measurement points results from the accuracy of coordinate measurements, the time needed to complete measurement tasks, the number of measurement points, the accuracy of the substitute surface representing the measured free-form surface and the area where measurement points are located. The purpose of using the developed method of the distribution of measurement points is to increase the performance of coordinate measurements primarily by increasing the automation of strategy planning of measurements of curvilinear surfaces and improving the accuracy of measurements of free-form surfaces of products. The new method takes into account various aspects of coordinate measurements to determine the final model of the distribution of measurement points on measured surfaces of products, thereby increasing the probability of the proper determination (i.e., identifying the highest deviations of a product) of the location of measurement points on the surfaces of a measured object. The paper presents an example of the application of the created method, which concerns the selection of the best model of the distribution of measurement points on a selected free-form surface. This example is based on, among others, the results of experimental investigations, which were carried out by using the ACCURA II coordinate measuring machine equipped with the VAST XXT measuring probe and the Calypso measurement software. The results of investigations indicate a significant reduction in time of coordinate measurements of products when using the new method for determining the distribution of measurement points. However, shortening the time of coordinate measurements does not reduce their accuracy.

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