公开(公告)号：US20190145755A1

公开(公告)日：2019-05-16

申请号：US16156030

申请日：2018-10-10

Applicant: ROLLS-ROYCE plc

Inventor： Murukeshan VADAKKE MATHAM ,  Kelvin H K CHAN ,  Guru Prasad ARUDI SUBBARAO ,  Prabhathan PATINHAREKANDY ,  Aswin HARIDAS ,  Pulkit KAPUR

IPC: G01B9/02 ,  G01B11/30

CPC classification number: G01B9/02096 ,  G01B9/02041 ,  G01B9/02094 ,  G01B11/30 ,  G01B11/303

Abstract: An imaging probe (102) for use in measuring surface roughness by angular speckle correlation is shown. The imaging probe comprises a first illumination fibre (201) to illuminate a sample location (103) on a surface, and having an input end for coupling of coherent light into the fibre, and an output end cleaved at an angle θ1, a second illumination fibre (202) to illuminate the sample location on the surface, and having an input end for coupling of coherent light into the fibre, and an output end cleaved at an angle θ2 that is different from θ1, and an image transmission system (204) for transmission of a to speckle pattern caused by illumination of the sample location on the surface by coherent light from either the first illumination fibre or the second illumination fibre.

公开(公告)号：US20200219273A1

公开(公告)日：2020-07-09

申请号：US16734503

申请日：2020-01-06

Applicant: ROLLS-ROYCE plc

Inventor： Vadakke Matham MURUKESHAN ,  Patinharekandy PRABHATHAN ,  Aswin HARIDAS ,  Pulkit KAPUR ,  Bilal M. NASSER ,  Kelvin H K CHAN

IPC: G06T7/41 ,  G06T7/521 ,  H04N13/128 ,  H04N13/156 ,  G06T7/593

Abstract: A method of measuring the surface roughness of a component using an optical system comprising a tunable laser light source and a camera system. Positioning the component to be measured upon a mount in front of the optical system. Capturing a first image of the component at a first location at a first wavelength λ1, and then capturing a second image of the component at the first location at a second wavelength λ2. Determining the Speckle Statistical Correlation (SSC) coefficient of the first and second images. Plotting the SSC coefficient for the combined first and second images. Calculating the roughness parameters Ra and Rq from the SSC coefficient plot. Plotting a roughness map for the imaged surface from the calculated roughness parameters Ra and Rq. Moving the optical system to a new location and repeating steps (b) to (f) at the new location, and repeating these steps until a desired area of the component has been imaged. Stitching the roughness maps for each location to form an overall roughness map for the desired area of the component.