Professor RICHARD LEACH's Outputs (118)

Optical measurement of surface topographies with transparent coatings (2019)
Journal Article
Feng, X., Senin, N., Su, R., Ramasamy, S., & Leach, R. (2019). Optical measurement of surface topographies with transparent coatings. Optics and Lasers in Engineering, 121, 261-270. https://doi.org/10.1016/j.optlaseng.2019.04.018

Manufacturers nowadays have access to state-of-the-art areal surface topography measurement instruments that allow investigation of surface topography at unprecedented levels of detail and over a wide range of scales. However, high value-added produc... Read More about Optical measurement of surface topographies with transparent coatings.

Lateral error compensation for stitching-free measurement with focus variation microscopy (2019)
Journal Article
Pérez, P., Syam, W. P., Antonio Albajez, J., Santolaria, J., & Leach, R. (2019). Lateral error compensation for stitching-free measurement with focus variation microscopy. Measurement Science and Technology, 30(6), Article 065002. https://doi.org/10.1088/1361-6501/ab046e

This paper proposes a practical methodology to quantify and compensate lateral errors for focus variation microscopy measurements without stitching. The main advantages of this new methodology are its fast and simple implementation using any uncalibr... Read More about Lateral error compensation for stitching-free measurement with focus variation microscopy.

Towards superresolution surface metrology: quantum estimation of angular and axial separations (2019)
Journal Article
Napoli, C., Piano, S., Leach, R., Adesso, G., & Tufarelli, T. (2019). Towards superresolution surface metrology: quantum estimation of angular and axial separations. Physical Review Letters, 122(14), Article 140505. https://doi.org/10.1103/physrevlett.122.140505

We investigate the localization of two incoherent point sources with arbitrary angular and axial separations in the paraxial approximation. By using quantum metrology techniques, we show that a simultaneous estimation of the two separations is achiev... Read More about Towards superresolution surface metrology: quantum estimation of angular and axial separations.

Residual flatness and scale calibration for a point autofocus surface topography measuring instrument (2019)
Journal Article
Maculotti, G., Feng, X., Su, R., Galetto, M., & Leach, R. K. (2019). Residual flatness and scale calibration for a point autofocus surface topography measuring instrument. Measurement Science and Technology, 30(7), https://doi.org/10.1088/1361-6501/ab188f

Point autofocus instruments are often used for measuring the surface topography of objects with complex geometry. Determining the metrological characteristics of the instrument is key to ensuring a traceable areal surface topography measurement. In t... Read More about Residual flatness and scale calibration for a point autofocus surface topography measuring instrument.

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.

Resolution enhancement for topography measurement of high-dynamic-range surfaces via image fusion (2018)
Journal Article
Wang, J., Su, R., Leach, R., Lu, W., Zhou, L., & Jiang, X. (2018). Resolution enhancement for topography measurement of high-dynamic-range surfaces via image fusion. Optics Express, 26(26), 34805-34819. https://doi.org/10.1364/OE.26.034805

In this paper, we introduce a method and algorithm for resolution enhancement of low-resolution surface topography data by fusing it with corresponding high-resolution intensity images. This fusion is carried out by linking the three-dimensional topo... Read More about Resolution enhancement for topography measurement of high-dynamic-range surfaces via image fusion.

Areal topography measurement of metal additive surfaces using focus variation microscopy (2018)
Journal Article
Newton, L., Senin, N., Gomez, C., Danzl, R., Helmli, F., Blunt, L., & Leach, R. (2019). Areal topography measurement of metal additive surfaces using focus variation microscopy. Additive Manufacturing, 25, 365-389. https://doi.org/10.1016/j.addma.2018.11.013

In this work, the performance of a focus variation instrument for measurement of areal topography of metal additive surfaces was investigated. Samples were produced using both laser and electron beam powder bed fusion processes with some of the most... Read More about Areal topography measurement of metal additive surfaces using focus variation microscopy.

Mechanical vibration bandgaps in surface-based lattices (2018)
Journal Article
Elmadih, W., Syam, W. P., Maskery, I., Chronopoulos, D., & Leach, R. (2019). Mechanical vibration bandgaps in surface-based lattices. Additive Manufacturing, 25, 421-429. https://doi.org/10.1016/j.addma.2018.11.011

In this paper, the phonon dispersion curves of several surface-based lattices are examined, and their energy transmission spectra, along with the corresponding bandgaps are identified. We demonstrate that these bandgaps may be controlled, or tuned, t... Read More about Mechanical vibration bandgaps in surface-based lattices.

Rapid tracking of extrinsic projector parameters in fringe projection using machine learning (2018)
Journal Article
Stavroulakis, P., Chen, S., Delorme, C., Bointon, P., Tzimiropoulos, G., & Leach, R. (2019). Rapid tracking of extrinsic projector parameters in fringe projection using machine learning. Optics and Lasers in Engineering, 114, 7-14. https://doi.org/10.1016/j.optlaseng.2018.08.018

In this work, we propose to enable the angular re-orientation of a projector within a fringe projection system in real-time without the need for re-calibrating the system. The estimation of the extrinsic orientation parameters of the projector is per... Read More about Rapid tracking of extrinsic projector parameters in fringe projection using machine learning.

In-process measurement of the surface quality for a novel finishing process for polymer additive manufacturing (2018)
Journal Article
Syam, W. P., Leach, R., Rybalcenko, K., Gaio, A., & Crabtree, J. (2018). In-process measurement of the surface quality for a novel finishing process for polymer additive manufacturing. Procedia CIRP, 75, 108-113. https://doi.org/10.1016/j.procir.2018.04.088

In the last decade, there has been considerable growth in the production of end-use polymer parts and components using additive manufacturing methods. A wide range of polymers, from Nylon-12 to thermoplastic polyurethane polymers, can be processed wi... Read More about In-process measurement of the surface quality for a novel finishing process for polymer additive manufacturing.

Information-rich surface metrology (2018)
Journal Article
Senin, N., & Leach, R. K. (2018). Information-rich surface metrology. Procedia CIRP, 75, 19-26. https://doi.org/10.1016/j.procir.2018.05.003

Information-rich metrology refers to the incorporation of any type of available information in the data acquisition and processing pipeline of a measurement process, in order to improve the efficiency and quality of the measurement. In this work, the... Read More about Information-rich surface metrology.

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., Bate, D., Woolliams, P., Brown, S., & 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.

In-process measurement and monitoring of a polymer laser sintering powder bed with fringe projection (2018)
Journal Article
Southon, N., Stavroulakis, P., Goodridge, R., & Leach, R. (2018). In-process measurement and monitoring of a polymer laser sintering powder bed with fringe projection. Materials and Design, 157, 227-234. https://doi.org/10.1016/j.matdes.2018.07.053

We investigate the feasibility of using fringe projection to monitor the powder bed of a polyamide 12 polymer laser sintering machine. In particular, we demonstrate the ability of fringe projection to identify a number of defects arising during the p... Read More about In-process measurement and monitoring of a polymer laser sintering powder bed with fringe projection.

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.

Fast and cost-effective in-process defect inspection for printed electronics based on coherent optical processing (2018)
Journal Article
Feng, X., Su, R., Happonen, T., Liu, J., & Leach, R. (2018). Fast and cost-effective in-process defect inspection for printed electronics based on coherent optical processing. Optics Express, 26(11), https://doi.org/10.1364/OE.26.013927

This paper presents an all-optical difference engine (AODE) sensor for detecting the defects in printed electronics produced with roll-to-roll processes. The sensor is based on the principle of coherent optical subtraction and is able to achieve high... Read More about Fast and cost-effective in-process defect inspection for printed electronics based on coherent optical processing.

A self-calibration rotational stitching method for precision measurement of revolving surfaces (2018)
Journal Article
Liu, M., Cheung, C., Feng, X., Wang, C., & Leach, R. (in press). A self-calibration rotational stitching method for precision measurement of revolving surfaces. Precision Engineering, https://doi.org/10.1016/j.precisioneng.2018.05.002

When measuring revolving objects, it is often desired to obtain not only the geometrical form of the workpiece, but also the topography of the surface, as they both affect the performance of the part. However, holistic measurement of the entire three... Read More about A self-calibration rotational stitching method for precision measurement of revolving surfaces.

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.

Hierarchical-information-based characterization of multiscale structured surfaces (2018)
Journal Article
Cheung, C. F., Liu, M., Leach, R., Feng, X., & Zhao, C. (2018). Hierarchical-information-based characterization of multiscale structured surfaces. CIRP Annals - Manufacturing Technology, 67(1), 539-542. https://doi.org/10.1016/j.cirp.2018.04.002

© 2018 This paper presents a hierarchical-information-based characterization method for multiscale structured surfaces. The method makes use of a priori information of the multiscale surface and a hierarchical segmentation–registration (HSR) algorith... Read More about Hierarchical-information-based characterization of multiscale structured surfaces.