公开(公告)号：US20180286059A1

公开(公告)日：2018-10-04

申请号：US15944247

申请日：2018-04-03

Applicant: ROLLS-ROYCE plc

Inventor： Murukeshan VADAKKE MATHAM ,  Aswin HARIDAS ,  Alexandru CRIVOI ,  Prabhathan PATINHAREKANDY

IPC: G06T7/48 ,  G06T7/194 ,  G06T7/136 ,  G01B11/30

Abstract: A measurement system (301) for determining surface roughness is shown. A coherent illumination device (303) illuminates the surface of, for example, a component (201) with coherent light. An imaging device (304) obtains an image of speckle caused by the scattering of the coherent light from the surface. A processing device (305) converts the image into a binary image according to a threshold, thereby classifying pixels below the threshold as background pixels and pixels above the threshold as foreground pixels. It then evaluates the fractal dimension of the binary image. The fractal dimension correlates with surface roughness. An indication of the surface roughness of the surface is then outputted.

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.

公开(公告)号：US20190257764A1

公开(公告)日：2019-08-22

申请号：US16260186

申请日：2019-01-29

Applicant: ROLLS-ROYCE plc

Inventor： Wei Keong TEN ,  Murukeshan VADAKKE MATHAM ,  Iulian MARINESCU ,  Nicholas WEEKS ,  Wei Yi YEOH ,  Aswin HARIDAS

IPC: G01N21/88 ,  G06T7/00 ,  F01D21/00 ,  G01N21/954

Abstract: There is described an inspection device for inspecting a slot of a gas turbine engine. The inspection device comprises: an insert for insertion into the slot; a plurality of imaging devices coupled to the insert; and a processor. The insert is movable along a longitudinal axis of the slot. Each of the plurality of imaging devices is positioned adjacent an external surface of the insert and is configured to capture an image of a portion of the slot adjacent the imaging device. The processor is configured to receive data corresponding to the images captured by the plurality of imaging devices. There is also described a method of inspecting a slot using the inspection device.

公开(公告)号：US20180286058A1

公开(公告)日：2018-10-04

申请号：US15944272

申请日：2018-04-03

Applicant: ROLLS-ROYCE plc

Inventor： Murukeshan VADAKKE MATHAM ,  Aswin HARIDAS ,  Alexandru CRIVOI ,  Prabhathan PATINHAREKANDY

IPC: G06T7/40 ,  G06T7/194 ,  G06T7/136

Abstract: A measurement system (301) for determining surface roughness is shown. A coherent illumination device (303) illuminates the surface of, for example, a component (201) with coherent light. An imaging device (304) obtains an image of speckle caused by the scattering of the coherent light from the surface. A processing device (305) converts the image into a binary image according to a threshold, thereby classifying pixels below the threshold as background pixels and pixels above the threshold as foreground pixels. One or more regions of connected foreground pixels are then identified in the binary image, in which any two foreground pixels in a region are joined by a continuous path of foreground pixels. The total number of regions identified and the number of pixels in the largest region are then evaluated, each of which correlate with surface roughness. An indication of the surface roughness of the surface is then outputted.