scholarly journals Recent developments on an interferometric multilateration measurement system for large volume coordinate metrology

2021 ◽  
Author(s):  
Eva Katharina Rafeld ◽  
Nils Koppert ◽  
Matthias Franke ◽  
Frank Keller ◽  
Daniel Heißelmann ◽  
...  
Keyword(s):  
Measurement System ◽  
Large Volume ◽  
Coordinate Measuring Machine ◽  
Mathematical Background ◽  
Large Complex ◽  
Complex Shapes ◽  
Coordinate Metrology ◽  
Recent Developments ◽  
Measuring Machine ◽  
Propagation Of Uncertainties

Abstract A mobile multilateration measurement system developed at the Physikalisch-Technische Bundesanstalt (PTB) around 2010 has been thoroughly investigated and refined to gain better performance with smaller uncertainties even when applied to the calibration of large complex workpieces. The mathematical background of multilateration and the propagation of uncertainties for the algorithms involved is explained in detail. Using the example of simple 1D and 2D measuring tasks, the influence of certain parameters characterizing the setup of the measurement system on the overall uncertainty is quantified. A strategy is developed to incorporate multi-stylus measurements which are often inevitable when workpieces feature complex shapes. The findings are verified on a large involute gear which is 2 m in diameter. All measurements are performed on PTB's large coordinate measuring machine with a working range of 5 m x 4 m x 2 m.

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.

Measurement System for Non-Cylinder Pin Hole of Piston

2011 ◽  
Vol 301-303 ◽  
pp. 617-622
Author(s):  
Z. Y. Yang ◽  
D. H. Liu ◽  
F. Yang ◽  
Z. G. Xie ◽  
Y. Huang
Keyword(s):  
High Precision ◽  
Measurement System ◽  
Coordinate Measuring Machine ◽  
Measuring Instrument ◽  
Movement Error ◽  
Pneumatic Measuring ◽  
Software Modules ◽  
Measuring Machine

Aim to the low measuring precision of non-cylinder pin hole using the coordinate measuring machine(CMM)and pneumatic measuring instrument, a new solution is proposed which use the high-precision digital lever probe to detect the contours of pin hole with a single clamping situation. The measuring principal of non-cylinder pin hole of piston is introduced and the functions and measuring processes of the measurement system are also presented. The software modules are given and the probe centering error and the parallelism movement error are discussed detailedly. A measuring example is given in the end. The measuring results show that the measurement system has the ability to detect the contours of pin hole with high-precision and efficiently.

Computer-Aided Coordinate Metrology

1993 ◽  
Author(s):  
Hong-Tzong Yau ◽  
Chia-Hsiang Menq
Keyword(s):  
Three Dimensional ◽  
Coordinate Measuring Machine ◽  
Computer Integrated Manufacturing ◽  
Integrated Manufacturing ◽  
Coordinate Metrology ◽  
Cad Cam ◽  
Measuring Machine ◽  
Three Dimensional Coordinate ◽  
Inspection Machine ◽  
Accuracy And Repeatability

Abstract Three-dimensional coordinate metrology has gained much attention in recent years. On one hand, the accuracy and repeatability of a coordinate measuring machine (CMM) are approaching the sub-micron level. On the other hand, there is hardly any part that exists of which the dimensions cannot be measured with a CMM. This paper presents the recent development and applications in three-dimensional coordinate metrology. The emphasis has been placed in the utilization of computers and integration with CAD/CAM systems. Three important technologies, namely, CAD-directed inspection, three-dimensional optimal match, and reverse engineering are presented and discussed. With computers and CAD/CAM support, three-dimensional coordinate metrology has become an active part of the computer-integrated manufacturing (CIM). Its versatility and high degree of automation have made the CMM a universal inspection machine for quality control of manufactured parts in computer integrated manufacturing.

Comparative Statistical Analysis of Test Parts Manufactured in Production Environments

2004 ◽  
Vol 126 (1) ◽  
pp. 189-199 ◽  
Author(s):  
David E. Gilsinn ◽  
Alice V. Ling
Keyword(s):  
Statistical Analysis ◽  
Machine Tool ◽  
Coordinate Measuring Machine ◽  
Hole Center ◽  
Machining Center ◽  
Production Environments ◽  
Measuring Machine ◽  
Comparative Statistical Analysis ◽  
Uncertainty Models ◽  
Propagation Of Uncertainties

Estimating error uncertainties arising in production parts is not a well-understood process. An approach to estimate these uncertainties was developed in this study. Machine tool error components were measured on a three-axis vertical machining center. Multiple parts were produced on the measured machining center then measured on a coordinate measuring machine. Uncertainty models for hole-center to hole-center lengths and orthogonalities were developed using measured machine tool errors. These estimated uncertainties were compared against measured uncertainties. The main conclusion from the study is that the Law of Propagation of Uncertainties can be used to estimate machining uncertainties.

Application of the sampling strategies in the inspection process

2017 ◽  
Vol 231 (4) ◽  
pp. 565-575 ◽  
Author(s):  
Syed Hammad Mian ◽  
Abdulrahman M Al-Ahmari
Keyword(s):  
Sample Size ◽  
Adaptive Sampling ◽  
Sampling Methods ◽  
Fundamental Problem ◽  
Coordinate Measuring Machine ◽  
Sampling Strategy ◽  
Point Distribution ◽  
Coordinate Metrology ◽  
Inspection Process ◽  
Measuring Machine

The selection of appropriate sample size and point distribution on the measuring surface has been a fundamental problem in the contemporary coordinate metrology. It is usually resolved by the users depending on their instinct or prior experience. As a result, inspection results have to be compromised between accuracy and measurement time. However, to deliver quality products in minimum time, effort, and cost, a reliable and an efficient sampling plan is mandatory. Although there have been a remarkable progress due to the development of various procedures for computing the sample size and selecting the appropriate point distribution, still users are inconversant with the characteristics and applications of the available sampling methods due to the absence of a proper review. Accordingly, a systematic review, giving insight into the various strategies available for the sample size and the point distribution, is presented. In this article, different algorithms and their application in the estimation of sample size and point distribution have been reviewed comprehensively. The classification of sampling methods and the importance of adaptive sampling have also been described. It has been concluded that the effectiveness of inspection process or the performance of coordinate measuring machine can be escalated through the application of a suitable sampling strategy. Therefore, the metrologists should either develop an effective method for defining sampling strategy or select the most suitable method from the available resources before carrying out the inspection process.

scholarly journals Analysis and Realization of Sampling Strategy in Coordinate Metrology

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Syed Hammad Mian ◽  
Abdulrahman Al-Ahmari ◽  
Hisham Alkhalefah
Keyword(s):  
Grid Point ◽  
Coordinate Measuring Machine ◽  
Sampling Strategy ◽  
Surface Characteristics ◽  
Optimization Techniques ◽  
Point Distribution ◽  
Solution Approach ◽  
Coordinate Metrology ◽  
Measuring Machine ◽  
Distribution Algorithms

The stringent customer demands and competitive market emphasize the importance of efficient and effective inspection in industrial metrology. Therefore, the implementation of an appropriate sampling strategy, i.e., the number of points and their distribution, has become very important in the inspection process using a coordinate measuring machine. Moreover, the quality of inspection results has frequently been influenced by sampling plan as well as workpiece size and surface characteristics. It has been an indispensable problem in the present-day measurement processes. Thus, this paper investigates various sample sizes and different point distribution algorithms that can be employed in the evaluation of form error. The effect of specimen size and surface quality on the sampling strategy has also been investigated. Furthermore, this work employs a fuzzy based Technique for Order Performance by Similarity to Ideal Solution approach to realize the best sampling strategy. The results have demonstrated the significance of robust optimization techniques as well as the importance of a suitable sampling strategy in coordinate metrology. This study has also established that Poisson point distribution achieved the best accuracy and the Grid point distribution had taken the least measurement time.

scholarly journals Digital Twin of an Optical Measurement System

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6638
Author(s):  
Michiel Vlaeyen ◽  
Han Haitjema ◽  
Wim Dewulf
Keyword(s):  
Measurement Uncertainty ◽  
Measurement System ◽  
Optical Measurement ◽  
Coordinate Measuring Machine ◽  
Plane Angle ◽  
Optical Measurement System ◽  
Digital Twin ◽  
Digital Twins ◽  
Measuring Machine ◽  
Line Scanner

Digital twins of measurement systems are used to estimate their measurement uncertainty. In the past, virtual coordinate measuring machines have been extensively researched. Research on digital twins of optical systems is still lacking due to the high number of error contributors. A method to describe a digital twin of an optical measurement system is presented in this article. The discussed optical system is a laser line scanner mounted on a coordinate measuring machine. Each component of the measurement system is mathematically described. The coordinate measuring machine focuses on the hardware errors and the laser line scanner determines the measurement error based on the scan depth, in‑plane angle and out‑of‑plane angle. The digital twin assumes stable measurement conditions and uniform surface characteristics. Based on the Monte Carlo principle, virtual measurements can be used to determine the measurement uncertainty. This is demonstrated by validating the digital twin on a set of calibrated ring gauges. Two validation tests are performed: the first verifies the virtual uncertainty estimation by comparison with experimental data. The second validates the measured diameter of different ring gauges by comparing the estimated confidence interval with the calibrated diameter.

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