All Outputs (126)

Comparison of rigorous scattering models to accurately replicate the behaviour of scattered electromagnetic waves in optical surface metrology (2024)
Journal Article
Hooshmand, H., Pahl, T., Hansen, P.-E., Fu, L., Birk, A., Karamehmedović, M., Lehmann, P., Reichelt, S., Leach, R., & Piano, S. (2025). Comparison of rigorous scattering models to accurately replicate the behaviour of scattered electromagnetic waves in optical surface metrology. Journal of Computational Physics, 521, Article 113519. https://doi.org/10.1016/j.jcp.2024.113519

Rigorous scattering models are based on Maxwell's equations and can provide high-accuracy solutions to model electromagnetic wave scattering from objects. Being able to calculate the scattered field from any surface geometry and considering the effec... Read More about Comparison of rigorous scattering models to accurately replicate the behaviour of scattered electromagnetic waves in optical surface metrology.

Applying machine learning to optical metrology: a review (2024)
Journal Article
Xue, R., Hooshmand, H., Isa, M., Piano, S., & K Leach, R. (2024). Applying machine learning to optical metrology: a review. Measurement Science and Technology, 36(1), Article 012002. https://doi.org/10.1088/1361-6501/ad7878

This literature review investigates the integration of machine learning (ML) into optical metrology, unveiling enhancements in both efficiency and effectiveness of measurement processes. With a focus on phase demodulation, unwrapping, and phase-to-he... Read More about Applying machine learning to optical metrology: a review.

In-situ measurement methods for microscale surface impurities in powder bed fusion: a review (2024)
Journal Article
Koca, A., Hooshmand, H., Leach, R., & Liu, M. (2025). In-situ measurement methods for microscale surface impurities in powder bed fusion: a review. Measurement Science and Technology, 36(1), Article 012001. https://doi.org/10.1088/1361-6501/ad824c

Despite ongoing improvements and optimisation efforts, the powder bed fusion (PBF) process continues to face challenges related to repeatability, robustness, and stability. These challenges can lead to the formation of microscale surface impurities o... Read More about In-situ measurement methods for microscale surface impurities in powder bed fusion: a review.

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.

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.

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.

Development of a compact focus variation microscopy sensor for on-machine surface topography measurement (2021)
Journal Article
Santoso, T., Syam, W. P., Darukumalli, S., & Leach, R. (2022). Development of a compact focus variation microscopy sensor for on-machine surface topography measurement. Measurement, 187, Article 110311. https://doi.org/10.1016/j.measurement.2021.110311

On-machine areal surface topography measuring instruments are required for fast and accurate measurement of parts inside production machines without reducing production rates. This paper presents the design and development of a compact focus variatio... Read More about Development of a compact focus variation microscopy sensor for on-machine surface topography measurement.

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.

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.

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.