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Outputs (94)

Extracting focus variation data from coherence scanning interferometric measurements (2024)
Journal Article
Liu, J., Hooshmand, H., Piano, S., Leach, R., Coupland, J., Ren, M., …Su, R. (2024). Extracting focus variation data from coherence scanning interferometric measurements. Precision Engineering, 88, 699-706. https://doi.org/10.1016/j.precisioneng.2024.04.016

Coherence scanning interferometry (CSI), based on the principle of interference, can achieve sub-nanometer precision for height measurements. On the other hand, focus variation microscopy (FVM), combining the small depth of field of the objective, is... Read More about Extracting focus variation data from coherence scanning interferometric measurements.

Comparison of Fourier optics-based methods for modeling coherence scanning interferometry (2024)
Journal Article
Hooshmand, H., Pahl, T., de Groot, P. J., Lehmann, P., Pappas, A., Su, R., …Piano, S. (2024). Comparison of Fourier optics-based methods for modeling coherence scanning interferometry. Optical Engineering, 63(4), Article 044102. https://doi.org/10.1117/1.OE.63.4.044102

Coherence scanning interferometry (CSI) is a widely used optical method for surface topography measurement of industrial and biomedical surfaces. The operation of CSI can be modeled using approximate physics-based approaches with minimal computationa... Read More about Comparison of Fourier optics-based methods for modeling coherence scanning interferometry.

Vision-based detection and coordinate metrology of a spatially encoded multi-sphere artefact (2023)
Journal Article
Isa, M. A., Leach, R., Branson, D., & Piano, S. (2024). Vision-based detection and coordinate metrology of a spatially encoded multi-sphere artefact. Optics and Lasers in Engineering, 172, Article 107885. https://doi.org/10.1016/j.optlaseng.2023.107885

New developments in vision algorithms prioritise identification and perception over accurate coordinate measurement due to the complex problem of resolving object form and pose from images. Consequently, many vision algorithms for coordinate measurem... Read More about Vision-based detection and coordinate metrology of a spatially encoded multi-sphere artefact.

Review of material measures for surface topography instrument calibration and performance verification (2023)
Journal Article
Pappas, A., Newton, L., Thompson, A., & Leach, R. (2024). Review of material measures for surface topography instrument calibration and performance verification. Measurement Science and Technology, 35(1), Article 012001. https://doi.org/10.1088/1361-6501/acf1b9

As the need for the manufacturing of complex surface topographies increases, traceable measurement with known uncertainties can allow a manufacturing process to remain stable. Material measures are the link in the chain that connects the surface topo... Read More about Review of material measures for surface topography instrument calibration and performance verification.

Comparison of approximate methods for modelling coherence scanning interferometry (2023)
Presentation / Conference Contribution
Hooshmand, H., Pahl, T., de Groot, P. J., Lehmann, P., Pappas, A., Su, R., …Piano, S. (2023). Comparison of approximate methods for modelling coherence scanning interferometry. Proceedings of SPIE, 12619, https://doi.org/10.1117/12.2673657

Coherence scanning interferometry (CSI) is a widely used optical method for surface topography measurement of industrial and biomedical surfaces. The operation of CSI can be modelled using approximate physics-based approaches with minimal computation... Read More about Comparison of approximate methods for modelling coherence scanning interferometry.

High-accuracy robotic metrology for precise industrial manipulation tasks (2023)
Presentation / Conference Contribution
Isa, M. A., Khanesar, M. A., Leach, R. K., Branson, D., & Piano, S. (2023). High-accuracy robotic metrology for precise industrial manipulation tasks. . https://doi.org/10.1117/12.2673088

The majority of industrial production processes can be divided into a series of object manipulation and handling tasks that can be adapted for robots. Through significant advances in compliant grasping, sensing and actuation technologies, robots are... Read More about High-accuracy robotic metrology for precise industrial manipulation tasks.

Comparison of coherence scanning interferometry, focus variation and confocal microscopy for surface topography measurement (2023)
Presentation / Conference Contribution
Hooshmand, H., Liu, M., Pappas, A., Thompson, A., Leach, R., & Piano, S. (2023). Comparison of coherence scanning interferometry, focus variation and confocal microscopy for surface topography measurement.

The most common optical technologies for surface topography measurement are coherence scanning interferometry (CSI), focus variation microscopy (FV) and imaging confocal microscopy (CM). Due to the benefits and drawbacks of each, these instruments ar... Read More about Comparison of coherence scanning interferometry, focus variation and confocal microscopy for surface topography measurement.

New Standard for Metal Powder Bed Fusion Surface Texture Measurement and Characterisation (2023)
Journal Article
Thompson, A., Newton, L., & Leach, R. (2023). New Standard for Metal Powder Bed Fusion Surface Texture Measurement and Characterisation. Metrology, 3(2), 237-245. https://doi.org/10.3390/metrology3020013

As metal additive manufacturing has been increasingly accepted as a viable method of industrial manufacture, there has been a significant uptake in manufacturers wishing to verify and test their parts through analysis of part surface. However, variou... Read More about New Standard for Metal Powder Bed Fusion Surface Texture Measurement and Characterisation.

A Neural Network Separation Approach for the Inclusion of Static Friction in Nonlinear Static Models of Industrial Robots (2023)
Journal Article
Ahmadieh Khanesar, M., Yan, M., Syam, W. P., Piano, S., Leach, R. K., & Branson, D. (2023). A Neural Network Separation Approach for the Inclusion of Static Friction in Nonlinear Static Models of Industrial Robots. IEEE/ASME Transactions on Mechatronics, 28(6), 3294-3304. https://doi.org/10.1109/TMECH.2023.3262644

Static friction modeling is a critical task to have the accurate robot model. In this article, a neural network separation approach to include nonlinear static friction in models of industrial robots is proposed. For this purpose, the terms correspon... Read More about A Neural Network Separation Approach for the Inclusion of Static Friction in Nonlinear Static Models of Industrial Robots.

Improving the localisation of features for the calibration of cameras using EfficientNets (2023)
Journal Article
Eastwood, J., Gayton, G., Leach, R. K., & Piano, S. (2023). Improving the localisation of features for the calibration of cameras using EfficientNets. Optics Express, 31(5), 7966-7982. https://doi.org/10.1364/OE.478934

Camera-based methods for optical coordinate metrology, such as digital fringe projection, rely on accurate calibration of the cameras in the system. Camera calibration is the process of determining the intrinsic and distortion parameters which define... Read More about Improving the localisation of features for the calibration of cameras using EfficientNets.

Autonomous image background removal for accurate and efficient close-range photogrammetry (2022)
Journal Article
Eastwood, J., Leach, R. K., & Piano, S. (2023). Autonomous image background removal for accurate and efficient close-range photogrammetry. Measurement Science and Technology, 34(3), Article 035404. https://doi.org/10.1088/1361-6501/aca497

Close-range photogrammetry can be used to reconstruct dense point clouds of an object with very high surface coverage, making it useful for manufacturing metrology tasks such as part inspection and validation. However, compared to competing technique... Read More about Autonomous image background removal for accurate and efficient close-range photogrammetry.

Evaluating parametric uncertainty using non-linear regression in fringe projection (2022)
Journal Article
Gayton, G., Isa, M., & Leach, R. K. (2023). Evaluating parametric uncertainty using non-linear regression in fringe projection. Optics and Lasers in Engineering, 162, Article 107377. https://doi.org/10.1016/j.optlaseng.2022.107377

Optical coordinate measurement systems, such as fringe projection systems, offer fast, high-density measurements of arbitrary surface topographies. The versatility, speed and information density of fringe projection measurements make them attractive... Read More about Evaluating parametric uncertainty using non-linear regression in fringe projection.

Frequency scanning interferometry for accurate robot position measurement (2022)
Presentation / Conference Contribution
Isa, M. A., Khanesar, M. A., Leach, R., Branson, D., & Piano, S. (2022). Frequency scanning interferometry for accurate robot position measurement. In Proceedings of 22nd International Conference & Exhibition

This paper presents a frequency scanning interferometry (FSI) shortwave infrared (IR) setup developed for position and orientation measurement of industrial robots. Within contemporary and future industrial frameworks, robots—in particular collaborat... Read More about Frequency scanning interferometry for accurate robot position measurement.

Detailed Three-Dimensional Building Façade Reconstruction: A Review on Applications, Data and Technologies (2022)
Journal Article
Klimkowska, A., Cavazzi, S., Leach, R., & Grebby, S. (2022). Detailed Three-Dimensional Building Façade Reconstruction: A Review on Applications, Data and Technologies. Remote Sensing, 14(11), 2579. https://doi.org/10.3390/rs14112579

Urban environments are regions of complex and diverse architecture. Their reconstruction and representation as three-dimensional city models have attracted the attention of many researchers and industry specialists, as they increasingly recognise the... Read More about Detailed Three-Dimensional Building Façade Reconstruction: A Review on Applications, Data and Technologies.

Surface measuring coherence scanning interferometry beyond the specular reflection limit (2021)
Journal Article
Thomas, M., Su, R., de Groot, P., Coupland, J., & Leach, R. (2021). Surface measuring coherence scanning interferometry beyond the specular reflection limit. Optics Express, 29(22), 36121-36131. https://doi.org/10.1364/OE.435715

The capability of optical surface topography measurement methods for measurement of steep and tilted surfaces is investigated through modelling of a coherence scanning interferometer. Of particular interest is the effect on the interference signal an... Read More about Surface measuring coherence scanning interferometry beyond the specular reflection limit.

Low thermal expansion machine frame designs using lattice structures (2021)
Journal Article
Juasiripukdee, P., Maskery, I., Ashcroft, I., & Leach, R. (2021). Low thermal expansion machine frame designs using lattice structures. Applied Sciences, 11(19), Article 9135. https://doi.org/10.3390/app11199135

In this work, we investigated tessellating cellular (or lattice) structures for use in a low thermal expansion machine frame. We proposed a concept for a lattice structure with tailorable effective coefficient of thermal expansion (CTE). The design i... Read More about Low thermal expansion machine frame designs using lattice structures.

Finite element modelling of defects in additively manufactured strut-based lattice structures (2021)
Journal Article
Echeta, I., Dutton, B., Leach, R. K., & Piano, S. (2021). Finite element modelling of defects in additively manufactured strut-based lattice structures. Additive Manufacturing, 47, Article 102301. https://doi.org/10.1016/j.addma.2021.102301

Strut-based lattice structures produced by powder bed fusion are prone to characteristic manufacturing defects that alter both their form and surface texture. Most studies in the literature focus on a subset of commonly observed defects, typically ra... Read More about Finite element modelling of defects in additively manufactured strut-based lattice structures.

Fourier optics modelling of coherence scanning interferometers (2021)
Presentation / Conference Contribution
de Groot, P. J., Colonna de Lega, X., Su, R., Coupland, J., & Leach, R. K. (2021). Fourier optics modelling of coherence scanning interferometers. In SPIE OPTICAL ENGINEERING + APPLICATIONS. https://doi.org/10.1117/12.2595668

We propose an instrument model for coherence scanning interferometry using familiar Fourier optics methods, the spectrum of plane waves, and the assumption that the light source spectral bandwidth is the dominant factor in determining fringe contrast... Read More about Fourier optics modelling of coherence scanning interferometers.

Efficient empirical determination of maximum permissible error in coordinate metrology (2021)
Journal Article
Thompson, A., Southon, N., Fern, F., Stupfler, G., & Leach, R. (2021). Efficient empirical determination of maximum permissible error in coordinate metrology. Measurement Science and Technology, 32(10), Article 105013. https://doi.org/10.1088/1361-6501/ac0c49

Maximum permissible errors (MPEs) are an important measurement system specification and form the basis of periodic verification of a measurement system's performance. However, there is no standard methodology for determining MPEs, so when they are no... Read More about Efficient empirical determination of maximum permissible error in coordinate metrology.

Evaluating and propagating uncertainty in digital fringe projection systems (2021)
Presentation / Conference Contribution
Gayton, G., Isa, M., Su, R., & Leach, R. (2021). Evaluating and propagating uncertainty in digital fringe projection systems. Proceedings of SPIE, 11782, https://doi.org/10.1117/12.2592426

Fringe projection is a measurement technique able to produce high-density data measurements of Lambertian surfaces using a camera and projector. Evaluating the uncertainty of a fringe projection system is challenging because of the highdensity and th... Read More about Evaluating and propagating uncertainty in digital fringe projection systems.

Physics-based virtual coherence scanning interferometer for surface measurement (2021)
Journal Article
Su, R., & Leach, R. (2021). Physics-based virtual coherence scanning interferometer for surface measurement. Light: Science and Applications, 2(2), 120-135. https://doi.org/10.37188/lam.2021.009

Virtual instruments provide task-specific uncertainty evaluation in surface and dimensional metrology. We demonstrate the first virtual coherence scanning interferometer that can accurately predict the results from measurements of surfaces with compl... Read More about Physics-based virtual coherence scanning interferometer for surface measurement.

Analysis of the tribological interaction of a polytetrafluoroethylene-lined radial lip oil seal, shaft and lubricant sample (2021)
Journal Article
Shabbir, S., Garvey, S. D., Dakka, S. M., Rothwell, B. C., Su, R., Leach, R., & Weston, N. (2022). Analysis of the tribological interaction of a polytetrafluoroethylene-lined radial lip oil seal, shaft and lubricant sample. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 236(1), 123-143. https://doi.org/10.1177/13506501211005876

To investigate the tribological interaction and wear mechanisms of polytetrafluoroethylene-lined radial lip oil seals in service, a sleeve, seal and lubricant sample taken off a rotating rig are studied. The test was terminated at 72 h, after severe... Read More about Analysis of the tribological interaction of a polytetrafluoroethylene-lined radial lip oil seal, shaft and lubricant sample.

Evaluating the cytotoxicity of Ge–Sb–Se chalcogenide glass optical fibres on 3T3 mouse fibroblasts (2021)
Journal Article
Mabwa, D., Kubiena, T., Parnell, H., Su, R., Furniss, D., Tang, Z., …Seddon, A. B. (2021). Evaluating the cytotoxicity of Ge–Sb–Se chalcogenide glass optical fibres on 3T3 mouse fibroblasts. RSC Advances, 11(15), 8682-8693. https://doi.org/10.1039/d0ra00353k

In vivo cancer detection based on the mid-infrared molecular fingerprint of tissue is promising for the fast diagnosis and treatment of suspected cancer patients. Few materials are mid-infrared transmissive, even fewer, which can be converted into fu... Read More about Evaluating the cytotoxicity of Ge–Sb–Se chalcogenide glass optical fibres on 3T3 mouse fibroblasts.

Characterisation of a multi-view fringe projection system based on the stereo matching of rectified phase maps (2021)
Journal Article
Shaheen, A., Sims-Waterhouse, D., Bointon, P., Takushima, S., Piano, S., & Leach, R. K. (2021). Characterisation of a multi-view fringe projection system based on the stereo matching of rectified phase maps. Measurement Science and Technology, 32(4), Article 045006. https://doi.org/10.1088/1361-6501/abd445

Multi-view fringe projection systems can be effective solutions to address the limitations imposed by the limited field of view, line-of-sight issues and occlusions when measuring the geometry of complex objects, associated with single camera-projec... Read More about Characterisation of a multi-view fringe projection system based on the stereo matching of rectified phase maps.

Statistical point cloud model to investigate measurement uncertainty in coordinate metrology (2021)
Journal Article
Senin, N., Catalucci, S., Moretti, M., & Leach, R. (2021). Statistical point cloud model to investigate measurement uncertainty in coordinate metrology. Precision Engineering, 70, 44-62. https://doi.org/10.1016/j.precisioneng.2021.01.008

In this work an approach to investigate measurement uncertainty in coordinate metrology is presented, based on fitting Gaussian random fields to high-density point clouds produced by measurement repeats. The fitted field delivers a depiction of the s... Read More about Statistical point cloud model to investigate measurement uncertainty in coordinate metrology.

Laser triangulation (2020)
Book Chapter
Isa, M. A., Piano, S., & Leach, R. Laser triangulation. In R. Leach (Ed.), Advances in Optical Form and Coordinate Metrology. IOP Publishing. https://doi.org/10.1088/978-0-7503-2524-0ch3

This chapter gives a summary of laser triangulation as a measurement technique and outlines recent applications and challenges.

Real-time target alignment system for high-power high-repetition rate laser operations using a five degree-of-freedom hybrid mechanism (2020)
Journal Article
Karim, S., Piano, S., Branson, D., Santoso, T., Leach, R., & Tolley, M. (2022). Real-time target alignment system for high-power high-repetition rate laser operations using a five degree-of-freedom hybrid mechanism. International Journal of Control, 95(4), 867-885. https://doi.org/10.1080/00207179.2020.1827297

This paper presents a real-time position control solution for the targets used in the high-repetition rate laser operations of large-scale high-power laser facilities. The design of the control system is based on an Abbe-compliant, in-process positio... Read More about Real-time target alignment system for high-power high-repetition rate laser operations using a five degree-of-freedom hybrid mechanism.

Mathematical approach to the validation of form removal surface texture software (2020)
Journal Article
Todhunter, L., Leach, R., & Blateyron, F. (2020). Mathematical approach to the validation of form removal surface texture software. Surface Topography: Metrology and Properties, 8(4), Article 045019. https://doi.org/10.1088/2051-672x/abc737

A new approach to the validation of surface texture form removal methods is introduced. A linear algebra technique is presented that obtains total least squares (TLS) model fits for a continuous mathematical surface definition. This model is applicab... Read More about Mathematical approach to the validation of form removal surface texture software.

Mathematical approach to the validation of surface texture filtration software (2020)
Journal Article
Todhunter, L., Leach, R., & Blateyron, F. (2020). Mathematical approach to the validation of surface texture filtration software. Surface Topography: Metrology and Properties, 8(4), Article 045017. https://doi.org/10.1088/2051-672X/abc0fb

A novel method for the validation of surface texture filtration software is introduced. Mathematically traceable reference pairs for linear Gaussian filtration are developed, utilising Fourier series surface definitions in conjunction with the freque... Read More about Mathematical approach to the validation of surface texture filtration software.

Optimisation of camera positions for optical coordinate measurement based on visible point analysis (2020)
Journal Article
Zhang, H., Eastwood, J., Isa, M., Sims-Waterhouse, D., Leach, R., & Piano, S. (2021). Optimisation of camera positions for optical coordinate measurement based on visible point analysis. Precision Engineering, 67, 178-188. https://doi.org/10.1016/j.precisioneng.2020.09.016

In optical coordinate measurement using cameras, the number of images, and positions and orientations of the cameras, are critical to object accessibility and the accuracy of a measurement. In this paper, we propose a technique to optimise the number... Read More about Optimisation of camera positions for optical coordinate measurement based on visible point analysis.

Surface-process correlation for an ink-jet printed transparent fluoroplastic (2020)
Journal Article
Gomez, C., Campanelli, C., Su, R., & Leach, R. (2020). Surface-process correlation for an ink-jet printed transparent fluoroplastic. Surface Topography: Metrology and Properties, 8(3), Article 034002. https://doi.org/10.1088/2051-672X/abac1c

Ink-jet printing is one of the key technologies in the field of defined polymer deposition. There is currently a lack of knowledge regarding how some fluoropolymers, in this case THV 221, can be ink-jet printed. A quantitative analysis of the micro-s... Read More about Surface-process correlation for an ink-jet printed transparent fluoroplastic.

Review of the influence of noise in X-ray computed tomography measurement uncertainty (2020)
Journal Article
Sánchez, Á. R., Thompson, A., Körner, L., Brierley, N., & Leach, R. (2020). Review of the influence of noise in X-ray computed tomography measurement uncertainty. Precision Engineering, 66, 382-391. https://doi.org/10.1016/j.precisioneng.2020.08.004

Different aspects of noise in X-ray computed tomography (XCT) for industrial purposes are examined. An overview of the most common noise metrics is given, together with a description of XCT noise influence quantities. We address the current state of... Read More about Review of the influence of noise in X-ray computed tomography measurement uncertainty.

Ceria-coated replicated aluminium sponges as catalysts for the CO-water gas shift process (2020)
Journal Article
Palma, V., Goodall, R., Thompson, A., Ruocco, C., Renda, S., Leach, R., & Martino, M. (2021). Ceria-coated replicated aluminium sponges as catalysts for the CO-water gas shift process. International Journal of Hydrogen Energy, 46(22), 12158-12168. https://doi.org/10.1016/j.ijhydene.2020.04.065

A study on the use of chemical conversion coating as a preparative technique for foam-based structured catalysts, in the water gas shift reaction, is presented. The results showed a significant correlation between the textural properties of the struc... Read More about Ceria-coated replicated aluminium sponges as catalysts for the CO-water gas shift process.

Volumetric error modelling of a stereo vision system for error correction in photogrammetric three-dimensional coordinate metrology (2020)
Journal Article
Isa, M. A., Sims-Waterhouse, D., Piano, S., & Leach, R. (2020). Volumetric error modelling of a stereo vision system for error correction in photogrammetric three-dimensional coordinate metrology. Precision Engineering, 64, 188-199. https://doi.org/10.1016/j.precisioneng.2020.04.010

Optical three-dimensional coordinate measurement using stereo vision has systematic errors that affect measurement quality. This paper presents a scheme for measuring, modelling and correcting these errors. The position and orientation of a linear st... Read More about Volumetric error modelling of a stereo vision system for error correction in photogrammetric three-dimensional coordinate metrology.

Real-time target alignment system for high-power high-repetition rate laser operations using a five degree-of-freedom hybrid mechanism (2020)
Journal Article
Leach, R., Branson, D., Karim, S., Tolley, M., Piano, S., & Santoso, T. (2020). Real-time target alignment system for high-power high-repetition rate laser operations using a five degree-of-freedom hybrid mechanism. International Journal of Control, 95(4), 867-885. https://doi.org/10.1080/00207179.2020.1827297

This paper presents a real-time position control solution for the targets used in the high-repetition rate laser operations of high-power laser facilities. The control system is designed based on an Abbe-compliant, in-process position measurement sys... Read More about Real-time target alignment system for high-power high-repetition rate laser operations using a five degree-of-freedom hybrid mechanism.

Mathematical approach to the validation of field surface texture parameter software (2020)
Journal Article
Todhunter, L., Leach, R., Lawes, S., Harris, P., & Blateyron, F. (2020). Mathematical approach to the validation of field surface texture parameter software. Surface Topography: Metrology and Properties, 8(1), Article 015010. https://doi.org/10.1088/2051-672x/ab7367

A new method for performance validation of surface texture parameter calculation software is introduced, focussing on field surface texture parameters. Surface height functions are defined mathematically, either using Fourier series or polynomials, a... Read More about Mathematical approach to the validation of field surface texture parameter software.

Polymer powder bed fusion surface texture measurement (2020)
Journal Article
de Pastre, M.-A., Thompson, A., Quinsat, Y., Albajez, J. A., Senin, N., & Leach, R. K. (2020). Polymer powder bed fusion surface texture measurement. Measurement Science and Technology, 31(5), Article 055002. https://doi.org/10.1088/1361-6501/ab63b1

Polymer laser powder bed fusion (LPBF) surfaces can be challenging to measure. These surfaces comprise complex features including undercuts, deep recesses, step-like transitions, a large range of measurement scales and unfavourable optically material... Read More about Polymer powder bed fusion surface texture measurement.

Performance Verification of a Flexible Vibration Monitoring System (2020)
Journal Article
Bointon, P., Todhunter, L., Clare, A., & Leach, R. (2020). Performance Verification of a Flexible Vibration Monitoring System. Machines, 8(1), 3. https://doi.org/10.3390/machines8010003

The performance of measurement or manufacturing systems in high-precision applications is dependent upon the dynamics of the system, as vibration can be a significant contributor to the measurement uncertainty and process variability. Technologies ma... Read More about Performance Verification of a Flexible Vibration Monitoring System.

Review of defects in lattice structures manufactured by powder bed fusion (2019)
Journal Article
Echeta, I., Dutton, B., Feng, X., Leach, R., & Piano, S. (2020). Review of defects in lattice structures manufactured by powder bed fusion. International Journal of Advanced Manufacturing Technology, 106(5-6), 2649–2668. https://doi.org/10.1007/s00170-019-04753-4

Additively manufactured lattice structures are popular due to their desirable properties, such as high specific stiffness and high surface area, and are being explored for several applications including aerospace components, heat exchangers and biome... Read More about Review of defects in lattice structures manufactured by powder bed fusion.

Uncertainty model for a traceable stereo-photogrammetry system (2019)
Journal Article
Sims-Waterhouse, D., Isa, M., Piano, S., & Leach, R. (2020). Uncertainty model for a traceable stereo-photogrammetry system. Precision Engineering, 63, 1-9. https://doi.org/10.1016/j.precisioneng.2019.12.008

Through the computational modelling and experimental verification of a stereo-photogrammetry system, the expanded uncertainty on form measurement was estimated and was found to be , and for a 95% confidence interval (coverage factors of = 3.2, 2.0... Read More about Uncertainty model for a traceable stereo-photogrammetry system.

Design and characterisation of an additive manufacturing benchmarking artefact following a design-for-metrology approach (2019)
Journal Article
Santos, V. M. R., Thompson, A., Sims-Waterhouse, D., Maskery, I., Woolliams, P., & Leach, R. (2020). Design and characterisation of an additive manufacturing benchmarking artefact following a design-for-metrology approach. Additive Manufacturing, 32, Article 100964. https://doi.org/10.1016/j.addma.2019.100964

We present the design and characterisation of a high-speed sintering additive manufacturing benchmarking artefact following a design-for-metrology approach. In an important improvement over conventional approaches, the specifications and operating pr... Read More about Design and characterisation of an additive manufacturing benchmarking artefact following a design-for-metrology approach.

Automated characterisation of multi-view fringe projection system for three- dimensional measurement of additively manufactured parts (2019)
Presentation / Conference Contribution
Leach, R. K., Shaheen, A., Piano, S., Sims-Waterhouse, D., & Bointon, P. (2019). Automated characterisation of multi-view fringe projection system for three- dimensional measurement of additively manufactured parts.

Digital fringe projection is a non-contact method that is widely used for the dimensional characterisation of complex manufactured parts. However, single camera-projector fringe projection systems struggle to acquire the full three-dimensional point... Read More about Automated characterisation of multi-view fringe projection system for three- dimensional measurement of additively manufactured parts.

Assessment of surface topography modifications through feature-based registration of areal topography data (2019)
Journal Article
Moretti, M., Gambucci, G., Leach, R., & Senin, N. (2019). Assessment of surface topography modifications through feature-based registration of areal topography data. Surface Topography: Metrology and Properties, 7(2), Article 025003. https://doi.org/10.1088/2051-672X/ab152a

Surface topography modifications due to wear or other factors are usually investigated by visual and microscopic inspection, and – when quantitative assessment is required – through the computation of surface texture parameters. However, the current... Read More about Assessment of surface topography modifications through feature-based registration of areal topography data.

Mathematical approach to the validation of functional surface texture parameter software (2019)
Journal Article
Todhunter, L., Leach, R., Lawes, S., Harris, P., & Blateyron, F. (2019). Mathematical approach to the validation of functional surface texture parameter software. Surface Topography: Metrology and Properties, 7(1), Article 015020. https://doi.org/10.1088/2051-672X/ab07ca

A new method for performance validation of surface texture parameter calculation software is introduced, focussing on functional surface texture parameters. Material ratio curves are defined algebraically and used to calculate functional surface text... Read More about Mathematical approach to the validation of functional surface texture parameter software.

Development of mathematical reference standards for the validation of surface texture parameter calculation software (2018)
Presentation / Conference Contribution
Todhunter, L., Leach, R., Lawes, S., Blateyron, F., & Harris, P. (2018). Development of mathematical reference standards for the validation of surface texture parameter calculation software. In n/a

A framework for the validation of surface texture parameter calculation software is proposed. The framework utilises mathematically defined surfaces and mathematically calculated surface texture parameter values to produce a reference against which t... Read More about Development of mathematical reference standards for the validation of surface texture parameter calculation software.

An interlaboratory comparison of X-ray computed tomography measurement for texture and dimensional characterisation of additively manufactured parts (2018)
Journal Article
Townsend, A., Racasan, R., Leach, R., Senin, N., Thompson, A., Ramsey, A., …Blunt, L. (2018). An interlaboratory comparison of X-ray computed tomography measurement for texture and dimensional characterisation of additively manufactured parts. Additive Manufacturing, 23, 422-432. https://doi.org/10.1016/j.addma.2018.08.013

This paper presents the results of the CT-STARR (CT-Surface Texture for Additive Round Robin) Stage 1 interlaboratory comparison. The study compared the results obtained for the extraction of areal surface texture data per ISO 25178-2 from five X-ray... Read More about An interlaboratory comparison of X-ray computed tomography measurement for texture and dimensional characterisation of additively manufactured parts.

Benchmarking of an additive manufacturing process (2018)
Presentation / Conference Contribution
Rivas Santos, V., Maskery, I., Sims-Waterhouse, D., Thompson, A., Leach, R., Ellis, A., & Woolliams, P. (2018). Benchmarking of an additive manufacturing process.

Band gap behavior of optimal one-dimensional composite structures with an additive manufactured stiffener (2018)
Journal Article
Ampatzidis, T., Leach, R. K., Tuck, C., & Chronopoulos, D. (2018). Band gap behavior of optimal one-dimensional composite structures with an additive manufactured stiffener. Composites Part B: Engineering, 153, https://doi.org/10.1016/j.compositesb.2018.07.012

In this work, the banded behaviour of composite one-dimensional structures with an additive manufactured stiffener is examined. A finite element method is used to calculate the stiffness, mass and damping matrices, and periodic structure theory is us... Read More about Band gap behavior of optimal one-dimensional composite structures with an additive manufactured stiffener.

Error modelling and validation of a high-precision five degree of freedom hybrid mechanism for high-power high-repetition rate laser operations (2018)
Journal Article
Karim, S., Piano, S., Leach, R. K., & Tolley, M. (2018). Error modelling and validation of a high-precision five degree of freedom hybrid mechanism for high-power high-repetition rate laser operations. Precision Engineering, 54, 182-197. https://doi.org/10.1016/j.precisioneng.2018.04.018

The accuracy, repeatability and speed requirements of high-power laser operations demand the employment of five degree of freedom motion control solutions that are capable of positioning and orientating the target with respect to the laser(s)-target... Read More about Error modelling and validation of a high-precision five degree of freedom hybrid mechanism for high-power high-repetition rate laser operations.

Photogrammetric coordinate metrology (2018)
Presentation / Conference Contribution
Sims-Waterhouse, D., Piano, S., & Leach, R. (2018, June). Photogrammetric coordinate metrology. Paper presented at euspen 18th International Conference & Exhibition

Fusion of photogrammetry and coherence scanning interferometry data for all-optical coordinate measurement (2018)
Journal Article
Leach, R., Sims-Waterhouse, D., Medeossi, F., Savio, E., Carmignato, S., & Su, R. (2018). Fusion of photogrammetry and coherence scanning interferometry data for all-optical coordinate measurement. CIRP Annals - Manufacturing Technology, 67(1), 599-602. https://doi.org/10.1016/j.cirp.2018.04.043

Multisensor data fusion is an approach to enlarge the potential applicability of measuring techniques and improve accuracy, taking advantage of the strengths of different techniques. In this work, we present a new method for the fusion of photogramme... Read More about Fusion of photogrammetry and coherence scanning interferometry data for all-optical coordinate measurement.

Development of mathematically-defined surfaces (2017)
Presentation / Conference Contribution
Todhunter, L. D., Leach, R., Lawes, S., Harris, P., & Blateyron, F. (2017). Development of mathematically-defined surfaces.

New software has been developed that enables the creation of areal surface topography representations. The goal of this software package is to utilise the mathematically-defined surface representations in the development of surface texture parameter... Read More about Development of mathematically-defined surfaces.

Defect evolution in laser powder bed fusion additive manufactured components during thermo-mechanical testing (2017)
Presentation / Conference Contribution
Xu, Z., Hyde, C. J., Thompson, A., Leach, R. K., Maskery, I., Tuck, C., & Clare, A. T. (2017). Defect evolution in laser powder bed fusion additive manufactured components during thermo-mechanical testing.

The mechanical performance of additively manufactured (AM) components remains an issue, limiting the implementation of AM technologies. In this work, a new method is presented, to examine the evolution of defects in an Inconel 718 two-bar test specim... Read More about Defect evolution in laser powder bed fusion additive manufactured components during thermo-mechanical testing.

True-color 3D surface metrology for additive manufacturing using interference microscopy (2017)
Presentation / Conference Contribution
DiSciacca, J., Gomez, C., Thompson, A., Lawes, S., Leach, R., Colonna de Lega, X., & de Groot, P. (2017). True-color 3D surface metrology for additive manufacturing using interference microscopy.

Coherence scanning interferometry (CSI) is widely used for surface topography characterisation. With the ability to measure both rough surfaces with the high slopes and optical finishes, CSI has made contibutions in fields from industrial machining t... Read More about True-color 3D surface metrology for additive manufacturing using interference microscopy.

Staged thermomechanical testing of nickel superalloys produced by selective laser melting (2017)
Journal Article
Xu, Z., Hyde, C. J., Thompson, A., Leach, R. K., Maskery, I., Tuck, C., & Clare, A. T. (2017). Staged thermomechanical testing of nickel superalloys produced by selective laser melting. Materials and Design, 133, 520-527. https://doi.org/10.1016/j.matdes.2017.08.009

The creep performance of additively manufactured components remains an issue before additive manufacturing can be put fully implemented. In this study, Inconel 718 two-bar specimens are produced by selective laser melting and subjected to a ‘staged’... Read More about Staged thermomechanical testing of nickel superalloys produced by selective laser melting.

Industrial survey of ISO surface texture parameters (2017)
Journal Article
Todhunter, L. D., Leach, R., Lawes, S., & Blateyron, F. (2017). Industrial survey of ISO surface texture parameters. CIRP Journal of Manufacturing Science and Technology, 19, https://doi.org/10.1016/j.cirpj.2017.06.001

Results of an international survey are presented, detailing the use of surface texture parameters in industry. The survey received 179 responses from a total of 34 countries, revealing the use of a variety of parameters from ISO 4287, ISO 12085, ISO... Read More about Industrial survey of ISO surface texture parameters.

Results of an industrial survey on the use of surface texture parameters (2017)
Presentation / Conference Contribution
Todhunter, L. D., Leach, R., & Lawes, S. (2017). Results of an industrial survey on the use of surface texture parameters.

In 1999, CIRP conducted an industrial survey of the use of surface texture parameters [1]. In the seventeen years since, much has changed, with the most important advancement being the introduction of areal surface texture parameters as described in... Read More about Results of an industrial survey on the use of surface texture parameters.

Design of mechanically-optimised lattice structures for vibration isolation (2017)
Presentation / Conference Contribution
Syam, W. P., Jianwei, W., Zhao, B., Maskery, I., & Leach, R. K. (2017). Design of mechanically-optimised lattice structures for vibration isolation.

In this study, we investigate the use of additively manufactured strut-based lattice structures to enhance the mechanical vibration isolation properties of a structure. Three lattice designs, inspired by the common strut-based lattice structures, are... Read More about Design of mechanically-optimised lattice structures for vibration isolation.

Detecting the signature of motion stage non-linearity for focus variation microscopy using measurement noise and surface topography repeatability (2017)
Presentation / Conference Contribution
Alburayt, A., Syam, W. P., & Leach, R. (2017). Detecting the signature of motion stage non-linearity for focus variation microscopy using measurement noise and surface topography repeatability.

Measurement noise is one of the ISO-proposed metrological characteristics of areal surface texture instruments [1, 2, 3, 4]. Measurement noise includes all of the unwanted contributions to the output signals when the instrument is used in its normal... Read More about Detecting the signature of motion stage non-linearity for focus variation microscopy using measurement noise and surface topography repeatability.

An industrial survey on the use of surface texture parameters (2017)
Presentation / Conference Contribution
Todhunter, L. D., Leach, R., & Lawes, S. D. (2017). An industrial survey on the use of surface texture parameters.

In 1999, CIRP conducted an industrial survey of the use of surface texture parameters [1]. In the seventeen years since, much has changed, with the most important advancement being the introduction of areal surface texture parameters as described in... Read More about An industrial survey on the use of surface texture parameters.

Coherence scanning interferometry for additive manufacture (2017)
Presentation / Conference Contribution
Gomez, C., Thompson, A., DiSciacca, J., Lawes, S., & Leach, R. (2017). Coherence scanning interferometry for additive manufacture.

Additive manufacture (AM) of metal components is a rapidly maturing technology; but given the large number of interrelated process parameters, it remains difficult to control to high precision. It has been observed that processing conditions may be a... Read More about Coherence scanning interferometry for additive manufacture.

X-ray computed tomography and additive manufacturing in medicine: a review (2017)
Journal Article
Thompson, A., McNally, D., Maskery, I., & Leach, R. K. (in press). X-ray computed tomography and additive manufacturing in medicine: a review. International Journal of Metrology and Quality Engineering, 8, Article 17. https://doi.org/10.1051/ijmqe/2017015

The use of X-ray computed tomography (XCT) with additive manufacture (AM) within a medical context is examined in this review. The seven AM process families and various XCT scanning techniques are explained in brief, and the use of these technologies... Read More about X-ray computed tomography and additive manufacturing in medicine: a review.

An analysis of type F2 software measurement standards for profile surface texture parameters (2017)
Journal Article
Todhunter, L. D., Leach, R. K., Lawes, S., & Blateyron, F. (2017). An analysis of type F2 software measurement standards for profile surface texture parameters. Measurement Science and Technology, 28(6), Article 065017. https://doi.org/10.1088/1361-6501/aa6924

This paper reports on an in-depth analysis of ISO 5436 part 2 type F2 reference software for the calculation of profile surface texture parameters that has been performed on the input, implementation and output results of the reference software devel... Read More about An analysis of type F2 software measurement standards for profile surface texture parameters.

Verification of micro-scale photogrammetry for smooth three-dimensional object measurement (2017)
Journal Article
Sims-Waterhouse, D., Piano, S., & Leach, R. (2017). Verification of micro-scale photogrammetry for smooth three-dimensional object measurement. Measurement Science and Technology, 28(5), Article 055010. https://doi.org/10.1088/1361-6501/aa6364

© 2017 IOP Publishing Ltd. By using sub-millimetre laser speckle pattern projection we show that photogrammetry systems are able to measure smooth three-dimensional objects with surface height deviations less than 1 μm. The projection of laser speckl... Read More about Verification of micro-scale photogrammetry for smooth three-dimensional object measurement.

Aerial wetting contact angle measurement using confocal microscopy (2016)
Journal Article
Chesna, J. W., Wiedmaier, B. F., Wang, J., Samara, A., Leach, R. K., Her, T.-H., & Smith, S. T. (in press). Aerial wetting contact angle measurement using confocal microscopy. Measurement Science and Technology, 27(12), https://doi.org/10.1088/0957-0233/27/12/125202

A method is presented in which the wetting contact angle of a sessile drop is acquired aerially using confocal techniques to measure the radius and the height of a droplet deposited on a planar surface. The repeatability of this method is typically l... Read More about Aerial wetting contact angle measurement using confocal microscopy.

Study of weighted fusion methods for the measurement of surface geometry (2016)
Journal Article
Wang, J., Pagani, L., Leach, R. K., Zeng, W., Colosimo, B. M., & Zhou, L. (2017). Study of weighted fusion methods for the measurement of surface geometry. Precision Engineering, 47, 111-121. https://doi.org/10.1016/j.precisioneng.2016.07.012

© 2016 Elsevier Inc. Four types of weighted fusion methods, including pixel-level, least-squares, parametrical and non-parametrical, have been classified and theoretically analysed in this study. In particular, the uncertainty propagation of the weig... Read More about Study of weighted fusion methods for the measurement of surface geometry.

Quadrature wavelength scanning interferometry (2016)
Journal Article
Moschetti, G., Forbes, A., Leach, R. K., Jiang, X., & O’Connor, D. (2016). Quadrature wavelength scanning interferometry. Applied Optics, 55(20), 5332-5340. https://doi.org/10.1364/ao.55.005332

A novel method to double the measurement range of wavelength scanning interferometry (WSI) is described. In WSI the measured optical path difference (OPD) is affected by a sign ambiguity, i.e. from an interference signal it is not possible to disting... Read More about Quadrature wavelength scanning interferometry.

Investigating mechanical characteristics of styli for micro-CMMs (2016)
Presentation / Conference Contribution
Ismail, M., Tseng, K., Claverley, J. D., Sheu, D., Chetwynd, D., & Leach, R. K. (2016). Investigating mechanical characteristics of styli for micro-CMMs.

The mechanical characteristics of styli for micro coordinate measuring machines (micro-CMMs) is of importance because of the major effect the styli have on the performance and capability of micro-CMMs. Previous work has focussed on the design of the... Read More about Investigating mechanical characteristics of styli for micro-CMMs.

Phase and fringe order determination in wavelength scanning interferometry (2016)
Journal Article
Moschetti, G., Forbes, A., Leach, R. K., Jiang, X., & O'Connor, D. (2016). Phase and fringe order determination in wavelength scanning interferometry. Optics Express, 24(8), 8997-9012. https://doi.org/10.1364/OE.24.008997

A method to obtain unambiguous surface height measurements using wavelength scanning interferometry with an improved repeatability, comparable to that obtainable using phase shifting interferometry, is reported. Rather than determining the conventio... Read More about Phase and fringe order determination in wavelength scanning interferometry.

Performance assessment of a new variable stiffness probing system for micro-CMMs (2016)
Journal Article
Alblahaihid, K., Kinnell, P., Lawes, S., Desgaches, D., & Leach, R. K. (2016). Performance assessment of a new variable stiffness probing system for micro-CMMs. Sensors, 16(4), Article 492. https://doi.org/10.3390/s16040492

When designing micro-scale tactile probes, a design trade-off must be made between the stiffness and flexibility of the probing element. The probe must be flexible enough to ensure sensitive parts are not damaged during contact, but it must be stiff... Read More about Performance assessment of a new variable stiffness probing system for micro-CMMs.

Review of post-process optical form metrology for industrial-grade metal additive manufactured parts (2016)
Journal Article
Stavroulakis, P., & Leach, R. K. (2016). Review of post-process optical form metrology for industrial-grade metal additive manufactured parts. Review of Scientific Instruments, 87(4), Article 041101. https://doi.org/10.1063/1.4944983

The scope of this review is to investigate the main post-process optical form measurement technologies available in industry today and to determine whether they are applicable to industrial-grade metal additive manufactured parts. An in-depth review... Read More about Review of post-process optical form metrology for industrial-grade metal additive manufactured parts.

An international comparison of surface texture parameters quantification on polymer artefacts using optical instruments (2016)
Journal Article
Tosello, G., Haitjema, H., Leach, R. K., Quagliotti, D., Gasparin, S., & Hansen, H. (in press). An international comparison of surface texture parameters quantification on polymer artefacts using optical instruments. CIRP Annals - Manufacturing Technology, 65(1), https://doi.org/10.1016/j.cirp.2016.04.003

An international comparison of optical instruments measuring polymer surfaces with arithmetic mean height values in the sub-micrometre range has been carried out. The comparison involved sixteen optical surface texture instruments (focus variation in... Read More about An international comparison of surface texture parameters quantification on polymer artefacts using optical instruments.

Quantification and characterisation of porosity in selectively laser melted Al–Si10–Mg using x-ray computed tomography (2016)
Journal Article
Maskery, I., Aboulkhair, N., Corfield, M., Tuck, C., Clare, A., Leach, R. K., …Hague, R. J. (2016). Quantification and characterisation of porosity in selectively laser melted Al–Si10–Mg using x-ray computed tomography. Materials Characterization, 111, https://doi.org/10.1016/j.matchar.2015.12.001

We used X-ray computed tomography (CT), microscopy and hardness measurements to study Al–Si10–Mg produced by selective laser melting (SLM). Specimens were subject to a series of heat treatments including annealing and precipitation hardening. The spe... Read More about Quantification and characterisation of porosity in selectively laser melted Al–Si10–Mg using x-ray computed tomography.

Laser ultrasound measurement of diaphragm thickness, Young’s modulus and Poisson’s ratio in a MEMS device
Journal Article
McKee, C., Culshaw, B., & Leach, R. K. (in press). Laser ultrasound measurement of diaphragm thickness, Young’s modulus and Poisson’s ratio in a MEMS device. IEEE Journal of Selected Topics in Quantum Electronics, https://doi.org/10.1109/JSTQE.2016.2635518

Laser-generated Lamb waves, coupled with a large bandwidth Michelson interferometer, have been demonstrated to accurately measure the thickness of a MEMS pressure sensor diaphragm in the [110] direction of a silicon wafer. Using the reassigned Gabor... Read More about Laser ultrasound measurement of diaphragm thickness, Young’s modulus and Poisson’s ratio in a MEMS device.