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Photometric stereo uses images of objects illuminated from various directions to calculate surface normals which can be used to generate 3D meshes of the object. Such meshes can be used by engineers to estimate damage of a concrete surface, or track damage progression over time to inform maintenance decisions. This dataset [1] was collected to quantify the uncertainty in a photometric stereo test rig through both the comparison with a well characterised method (coordinate measurement machine) and experiment virtualisation. Data was collected for 9 real objects using both the test rig and the coordinate measurement machine. These objects range from clay statues to damaged concrete slabs. Furthermore, synthetic data for 12 objects was created via virtual renders generated using Blender (3D software) [2]. The two methods of data generation allowed the decoupling of the physical rig (used to light and photograph objects) and the photometric stereo algorithm (used to convert images and lighting information into 3D meshes). This data can allow users to: test their own photometric stereo algorithms, with specialised data created for structural health monitoring applications; provide an industrially relevant case study to develop and test uncertainty quantification methods on test rigs for structural health monitoring of concrete; or develop data processing methodologies for the alignment of scaled, translated, and rotated data.

A comprehensive experimental methodology has been developed to measure the in situ cure residual strain (CRS) generation in carbon fiber reinforced polymer (CFRP) laminates using embedded fiber Bragg grating (FBG) sensors. In order to delineate the effect of anisotropy, heterogeneity, laminate thickness and geometry, in situ CRS is measured in pristine epoxy, uni-directional (UD)-CFRPs, multi-directional (MD)-CFRPs and L-shaped MD-CFRP laminates. In this study, emphasis is laid on quantifying the variation in CRS magnitudes as a function of laminates lay-up sequence and thickness. Calibration of FBG sensors are carried out by following well established procedures. Structural distortion due to CRS is correlated using embedded FBG sensor and measured using the coordinate measurement machine (CMM). The presented results show a uniform CRS development across the thickness in MD-CFRP laminates as compared to L-shaped MD-CFRP laminates. [ABSTRACT FROM AUTHOR]

Coordinate Measurement Machines (CMMs) have been extensively used in inspecting mechanical parts with higher accuracy. In order to enhance the efficiency and precision of the measurement of aviation engine blades, a sampling method of profile measurement of aviation engine blade based on the firefly algorithm is researched. Then, by comparing with the equal arc-length sampling algorithm (EAS) and the equi-parametric sampling algorithm (EPS) in one simulation, the proposed sampling algorithm shows its better sampling quality than the other two algorithms. Finally, the effectiveness of the algorithm is verified by an experimental example of blade profile. Both simulated and experimental results show that the method proposed in this paper can ensure the measurement accuracy by measuring a smaller number of points.

The aim of this study is to investigate the relationship between the fusion temperature and dimensional accuracy of the 3D printed components. The Computer Aided Design (CAD) model of specimens were prepared using Autodesk Inventor Software. Then the models were exported to STL file format for rapid prototyping. Prusa İ3 desktop type 3D printer with 90-300 microns layer height manufacturing capacity was used to produce the samples. The printer settings were prepared with Simplified3D software. Infill density and layer height of specimens were determined as 20% and 200 microns, respectively. The heated bed temperature was selected as 60 °C to increase the bonding and surface quality. The specimens were produced as sphere with the diameter of 10 mm. The samples were manufactured with five different extruder temperatures (185, 195, 205, 215, and 220 °C) that directly affect the fusing temperature and process. Three samples spheres were produced for each fusion temperature. After the design and manufacturing processes the dimensions of produced samples were measured with image processing techniques. The obtained results were compared with each other to find the relationship between the dimensional accuracy and fusion temperatures. The results showed that the minimum dimensional error was obtained from the fusion temperature of 185 °C with the value of 0.290797 mm and percentage of 3%. [ABSTRACT FROM AUTHOR]

Variational problems that arise in the course of minimization of the number of control points in coordinate measurements of the characteristics of form, orientation, and relative position of the geometric elements of articles is solved on the basis of analytic models of estimates of the errors under the condition of an upper bound on the value of the measurement error. The proposed methods of solution are illustrated by examples of planning of coordinate measurements of flatness, parallelism, and perpendicularity of planes, the distance between planes, the circularity parameters, and the coaxiality of cylinders. [ABSTRACT FROM AUTHOR]

In this research, methods and algorithms of calibration of optical schemes and elements of a triangulation laser system were analyzed. Recommendations for precision enhancement of an optical system are further used in improving parameters of a laser and reverse engineering they are also implemented in engineering of a high-speed linear laser 3D scanner. [ABSTRACT FROM AUTHOR]

This paper sets out the method of improving the accuracy of mechatronic systems used for measurements of complex geometry. At the core of this method is a programmed compensation of systematic errors (inaccuracies) of mechatronic systems. The difference of the proposed method from the existing solutions is that this method employs three relatively simple reference gauges: cylindrical, flat, and spherical. The methodology suggests measuring the reference gauges, calculating the compensation parameters and their subsequent accounting when deriving the results of measurements. The parameters of compensation of systemic errors are defined on the basis of the results of measurements of the said reference gauges of surfaces in a mechatronic system. This paper describes a model which enables to optimize the choice of parameters for measurement of reference gauges. The method may be applied for enhancement of the accuracy of measurements of mechatronic systems used in process-specific coordinate measurement machines. [ABSTRACT FROM AUTHOR]

This Coordinate Measuring Machines (C.M.M.) has had an increasingly important role throughout history. We are talking to an enterprise-level quality control. A system that is being implemented in all companies, and has developed some tools to control a variety of parameters such as production stabilization.In this paper, we first set out an introduction to the use of C.M.M. as tools for quality control in SME's. Then we explore the importance of piece positioning and clamping before being measured in a C.M.M. We finally analyze four possible moorings, and deviations are obtained. These moorings are designed in order to place the same work piece in the four cases.Finally, the results obtained are compared and show which is the best way to put the part on the C.M.M.

In this article, we present results that demonstrate the utility of close range photogrammetry in the measurement of decks in recreational craft as an alternate measurement system to the one based on direct acquisition of coordinates. The areas of deck covered with teakwood for aesthetic or security reasons were measured. Both methods were compared in terms of precision of measurements, time consumption, equipment cost, and ease of manipulation and equipment transportation. Based on the results, we conclude that photogrammetry has advantages in almost every aspect with respect to the direct method. Consequently, photogrammetry is suggested as a suitable method for coordinate measurement of decks in recreational ships. However, in some special circumstances, where ships have wide corridors with few obstacles the direct method can be more appropriate than the photogrammetric method.

This paper investigates on the use of advanced optical measurement methods, i.e. 3D coordinate measurement machines (3D CMM) and stereo-vision digital image correlation (3D DIC), for the mechanical analysis of shear deficient prestressed concrete members. Firstly, the experimental program is elaborated. Secondly, the working principle, experimental setup and corresponding accuracy and precision of the considered optical measurement techniques are reported. A novel way to apply synthesised strain sensor patterns for DIC is introduced. Thirdly, the experimental results are reported and an analysis is made of the structural behaviour based on the gathered experimental data. Both techniques yielded useful and complete data in comparison to traditional mechanical measurement techniques and allowed for the assessment of the mechanical behaviour of the reported test specimens. The identified structural behaviour presented in this paper can be used to optimize design procedure for shear-critical structural concrete members. [ABSTRACT FROM AUTHOR]

This paper is an overview of the main methods for measuring the thickness deep drawing parts, the main advantages and disadvantages. It's presented three measurement methods from the traditional ways to the coordinate measuring machine methods. The accuracy of the measurements is very important taking into account the precision we want to obtain. The analyze part was generated virtual in a CAD program. [ABSTRACT FROM AUTHOR]

Abstract: Quality inspection of micro systems on wafer scale must cope with conflicting demands: nanometer accuracy and high velocity in a comparatively large workspace. An Automated Multiscale Measuring System (AMMS) combines multiple sensors that operate at specific scales by an intelligent measurement strategy in order to balance speed and accuracy. The AMMS demonstrator is based on a modified Mahr MFU 100 with a position and tilt deflection measurement resolution of 1nm. In this paper multiscale models of a horizontal axis with an operating range of 200mm and their application to state linearization and control parameterization of the residual dynamics according to multiscale sensor system characteristics are developed and discussed. Main modeling issues are sliding and submicron presliding friction for model-based compensation and control, reaching from submicron positioning to high-velocity trajectory tracking with desired performance. A new experimental design for the identification of presliding friction parameters and a higher-order friction calculator are presented. Experimental results show the effectiveness of this approach. [Copyright &y& Elsevier]

Abstract: The paper reports on the design and testing of several new piezoresistive ultra high precision 3D microprobes for the use in coordinate measuring machines (CMM). The microprobes are all composed of three primary components a piezoresitive sensing element and stylus with probing sphere. The sensing element consists of a bossed KOH-etched silicon membrane with diffused piezoresistors. Several designs were investigated to increase sensor sensitivity while improving the anisotropy of stiffness. The initial design used a Wheatstone bridge piezoresistor configuration with a solid sensing membrane. Additionally, apertures where added to the solid silicon membrane to increase stress within the piezoresistors which untimely led to higher probe tip sensitivity. To improve the stiffness in the xy direction of the probe tip a double triangle design was tested that bonded two sensor chips back to back. This was found reduce the ratio between the stiffness in xy- and z-direction from 32 initially to 2. [ABSTRACT FROM AUTHOR]

Novel developments in micropattern detector technology require fast and precise methods to measure large area topologies in the order of a few square meters. Standard tactile coordinate measurement systems have resolutions better 10 μ m , but suffer from relatively long measuring time of several hours for one cycle. Sensitive structures may be damaged when touched by the tactile sensor. We present a method using laser distance sensors. Such a device is able to scan surfaces fast without touching them. The presented device has the capability to measure semitransparent surfaces. The vertical translator to mount the sensor is able to move in sub-mm steps. Using this we are able to measure the position and height of copper on FR4 with an accuracy better than 10 μ m . We report on the performance of the sensor scanning non-transparent as well as semi-transparent surfaces. This includes studies to minimize the measurement time without a loss in resolution. Our method to calibrate the measurement system will also be shown. This calibration is needed to reach a resolution better than 10 μ m . [ABSTRACT FROM AUTHOR]

In this article, we present results that demonstrate the utility of close range photogrammetry in the measurement of decks in recreational craft as an alternate measurement system to the one based on direct acquisition of coordinates. The areas of deck covered with teakwood for aesthetic or security reasons were measured. Both methods were compared in terms of precision of measurements, time consumption, equipment cost, and ease of manipulation and equipment transportation. Based on the results, we conclude that photogrammetry has advantages in almost every aspect with respect to the direct method. Consequently, photogrammetry is suggested as a suitable method for coordinate measurement of decks in recreational ships. However, in some special circumstances, where ships have wide corridors with few obstacles the direct method can be more appropriate than the photogrammetric method. [ABSTRACT FROM AUTHOR]

Ball tip and stylus tilt are two error sources found in coordinate measurement machines (CMMs). The magnitude of these errors is dependent on the ball tip radius and the degree of misalignment between the stylus motion axis and lateral referencing plane determined by the x and y axes of the CMM used. It is shown that these two errors are actually coupled and that their correction can be accomplished in one process. The overall benefit and versatility of this correction routine on a more general basis are given. [Copyright &y& Elsevier]

Rapid prototyping turns a three-dimensional CAD drawing into an actual part that can be tested for form, fit, and function. Therefore, accuracy of the prototype is important. The goal of this research was to improve in-plane dimensional accuracy for the Stratasys FDM 1650 rapid prototyping machine. The CHRISTMAS-TREE™ test procedure developed by 3D Systems, Inc., was used to arrive at a new shrinkage compensation factor (SCF) for the Stratasys machine. It was found that an SCF of 1.010 will produce a 53% reduction in mean error of the dimensions. More test procedures could be implemented to further refine accuracy. © 1999 John Wiley & Sons, Inc. Comput Appl Eng Educ 7: 186–195, 1999 [ABSTRACT FROM AUTHOR]

This paper presents a computer-integrated system for design, manufacturing simulation, and inspection using a coordinate measurement machine (CMM). The work is concerned with the problem of predicting the shape of the container for hot isostatic pressing (HIP) and it focuses on the verification of a finite element (FE) simulation model for HIP. The verification is performed by comparing the simulated geometry of a real component produced by HIP. The geometry of the HIP component is measured by a CMM. The whole process from design and manufactunng simulation to inspection and geometry verification is performed within a computer-aided concurrent engineering (CACE) system. The system is built on both commercial and non-commercial software. The communication between a CMM, a geometnc modelling system, and the finite element simulation codes is developed. The manufacturing of a turbine component to net shape geometry using HIP is chosen as a demonstrator example. The benefits of the presented CACE system are time and cost savings as well as higher product quality. [ABSTRACT FROM PUBLISHER]

• A comparative study on Coordinate Measurement Machine probe systems. • Scanning and touch-trigger probe system measurement uncertainties are compared. • No statistically significant difference is found in investigated geometries. • Scanning measurement method is quicker than touch-trigger method. • Insights are provided for industrial CMM reader base. An increasing level of research is focalising around the Coordinate Measurement Machine (CMM) as an important dimensional inspection instrumentation, that is utilised in a wide range of industrial metrology applications with its high precision measurement capabilities, flexibility and high measurement speed. The key functional section of the CMM is the probing system, that enables capturing of spatial coordinate data along measurement surfaces. This research compared the measurement performance parameters (measurement uncertainty and measuring time) of the scanning probing system against the touch-trigger probing system, conducting experiments for rectangular and spherical geometries on a CMM. As a result, it was concluded that there are no statistically significant differences between the scanning method uncertainty of scanning probing system and the touch-trigger measuring method uncertainty of touch-trigger probing system for investigated geometries. The scanning method was concluded as quicker with the disadvantage of relatively higher calibration time. Contributions are offered through extending current knowledge on CMM probing systems and guiding industrial CMM measurement strategies. [ABSTRACT FROM AUTHOR]