GB2597087A

GB2597087A - Method and apparatus

Info

Publication number: GB2597087A
Application number: GB2010833.8A
Authority: GB
Inventors: Tuckett John; Smith Andrew; Walker Timothy
Original assignee: British Steel PLC
Current assignee: British Steel PLC
Priority date: 2020-07-14
Filing date: 2020-07-14
Publication date: 2022-01-19
Also published as: GB202010833D0

Abstract

A method for inspecting a first part of a surface of an article having an axial length ‘L’ extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions comprises providing a set of non-contact profilometers 100 including a first profilometer 100A and defining a first measurement area. The article is then moved in the first dimension through the first measurement area by a conveyor. The first profilometer acquires a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area. The first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article. The profilometer transmits the first set of coordinate data to a computer. The computer determines the first part of the surface of the article based, at least in part, on the first segment. The computer further generates a first part of the surface of the article using the determined first part of the surface and compares the determined first part of the surface and the generated first part of the surface so as to inspect the article based on a first result of the comparison between the two. In use the method is suitable for the inspection of hot-rolled steel profiles to detect imperfections, occlusions and out of tolerance profiles caused by mill scale.

Description

Method and Apparatus

Field

The present invention relates to determining surfaces of articles using non-contact profilometry.

Background to the invention

Generally, thermomechanical processing of steel is used to form profiles (also known as sections) from semi-finished casting products. Thermomechanical processing typically combines mechanical and/or plastic deformation processes, for example rolling, forging, extrusion, drawing and/or rotary piercing with thermal processes, for example heat-treatment, water quenching, controlled heating and/or cooling. Hot rolling is an example of thermomechanical processing and is concerned with forming shapes and/or geometries of the profiles and/or modifying microstructural properties of the steel, for example. During hot rolling in rolling mills, a semi-finished casting product is typically heated above its recrystallization temperature in air and plastically deformed between one or more sets of rolls. Hot rolling permits large deformations to be achieved with a low number of rolling cycles.

Heating steel to such elevated temperatures in air results in formation of mill scale (also known as scale) on surfaces thereof. Scale is problematic since the scale may be pressed into the surface of the steel during subsequent forming and/or indent the steel during the subsequent forming. Hence, scale is typically removed by descaling including mechanical, thermal, hydraulic and/or chemical processing. However, an efficiency of descaling may be relatively low, such that residual scale remains on the steel. The residual scale is similarly problematic since the residual scale may be pressed into the surface of the steel during subsequent forming, including straightening, and/or indent the steel during the subsequent forming, resulting in surface defects which may result in quality control rejection of the steel. Some residual scale may spall from the surface during the subsequent forming and may be present as loose scale on the surface. This loose scale may be refined into dust by mechanical processing. Movement, including vibration, of the article may cause at least some of the loose scale and/or dust to fall from the surface and/or accumulate in processing machinery during the subsequent processing in the rolling mills, though some of the loose scale and/or dust may remain thereupon.

Hot rolling typically defines cross-sectional dimensions of the profiles while subsequent cold forming, such as straightening, may be used to improve axial parameters of the profiles. Cross-sectional parameters may include, for example, thicknesses, radii, squareness and/or concavity/convexity and axial dimensions may include, for example, straightness, unevenness and/or twist. Typically, the rolling mills are adaptable to process tens or even hundreds of profiles having different cross-sectional parameters, for example by changing rolls and/or roll stands, to output the profiles at rates of up to 10 ms-1 while rod mills may output profiles at rates of over 100 ms-1.

Dimensional tolerances of the profiles may be controlled, for example by standards, with respect to axial dimensions, cross-sectional dimensions, and/or defects, such as indentations. Typically, compliance with cross-sectional dimensional tolerances may be inspected manually using gauges, for example at a particular frequency along a length of a profile, while visual inspection may be used to assess the presence of defects in or on a proportion of accessible surfaces. Particularly, lengths of profiles are typically arranged statically on racks for inspection by human inspectors. Given the mass and size of these lengths, inspection is usually only possible from above and/or the sides, such that lower surfaces may not be inspected. In addition, the inherent interrelationships between the different dimensional tolerances, particularly cross-sectional dimensions, may make determination of compliance or otherwise complex. The inspection is typically performed after completion of processing, prior to despatch, when quality control rejection of profiles at such a late stage is costly. Furthermore, since such inspection is intermittent, parts of given length of a profile may be still be outside of permitted tolerances, resulting in later quality control rejection by a customer.

Hence, there is a need to improve inspection of articles, such as hot rolled steel profiles.

Summary of the Invention

It is one aim of the present invention, amongst others, to provide methods of and apparatuses for determining surfaces of moving articles, which at least partially obviates or mitigates at least some of the disadvantages of the prior art, whether identified herein or elsewhere. For instance, it is an aim of embodiments of the invention to provide a method of determining a first part of a surface of an article that accounts for transverse displacement of the article, for occlusions during the determining and/or for permitted tolerances of a cross-sectional profile of the article.

A first aspect provides a method of determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method implemented, at least in part, by a computer including a processor and a memory, the method comprising: providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; moving, by a conveyor, the article in the first dimension through the first measurement area; acquiring, by the first profilometer, a first segment of a set of segments of a zeroth measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a zeroth part of the surface of the article; displacing the moving article by a first displacement of a set of displacements in the second and/or the third dimension; acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; correcting, by the computer, the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile; and determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected first segment.

A second aspect provides an apparatus for determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the apparatus comprising: a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; a conveyor configured to move the article in the first dimension through the first measurement area; and a computer including a processor and a memory; wherein the first profilometer is configured to: acquire a first segment of a set of segments of a zeroth measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a zeroth part of the surface of the article; acquire a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article, wherein the moving article is displaced by a first displacement of a set of displacements in the second and/or the third dimension; and transmit the first set of coordinate data of the first segment of the first measured cross-sectional profile to the computer; and wherein the computer is configured to: receive the first set of coordinate data of the first segment of the first measured cross-sectional profile; correct the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile; and determine the first part of the surface of the article based, at least in part, on the corrected first segment.

A third aspect provides a computer for determining, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the computer comprising a processor and a memory, wherein the computer is configured to: receive a first set of coordinate data of a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article, wherein the moving article is displaced by a first displacement of a set of displacements in the second and/or the third dimension; correct the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile; and determine the first part of the surface of the article based, at least in part, on the corrected first segment.

A fourth aspect provides a tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by computer device including at least a processor and a memory, cause the computer device to perform a method of determining, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method according to the first aspect.

A fifth aspect provides a method of determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method implemented, at least in part, by a computer including a processor and a memory, the method comprising: providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; moving, by a conveyor, the article in the first dimension through the first measurement area; occluding, at least in part, the first part of the surface of the moving article by a first occlusion in the first measurement area; acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the occluded, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a first part of a surface of the first occlusion; transmitting, by the first profilometer, the first set of coordinate data of the first segment to the computer; receiving, by the computer, the first set of coordinate data of the first segment; correcting, by the computer, the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data; and determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected first segment.

A sixth aspect provides an apparatus for determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the apparatus comprising: a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; a conveyor configured to move the article in the first dimension through the first measurement area; and a computer including a processor and a memory; wherein the first profilometer is configured to: acquire a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a first part of a surface of a first occlusion; and transmit the first set of coordinate data of the first segment to the computer; and wherein the computer is configured to: receive the first set of coordinate data of the first segment; correct the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data; and determine the first part of the surface of the article based, at least in part, on the corrected first segment.

A seventh aspect provides a computer for determining, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the computer comprising a processor and a memory, wherein the computer is configured to: receive a first set of coordinate data of a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the article, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a first part of a surface of a first occlusion; correct the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data; and determine the first part of the surface of the article based, at least in part, on the corrected first segment.

An eighth aspect provides a tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by computer device including at least a processor and a memory, cause the computer device to perform a method of determining, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method according to the fifth aspect.

A ninth aspect provides a method of inspecting a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method implemented, at least in part, by a computer including a processor and a memory, the method comprising: providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; moving, by a conveyor, the article in the first dimension through the first measurement area; acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; determining, by the computer, the first part of the surface of the article based, at least in part, on the first segment; generating, by the computer, a generated first part of the surface of the article using the determined first part of the surface; comparing, by the computer, the determined first part of the surface and the generated first part of the surface; and inspecting, by the computer, the article based on a first result of the comparing.

A tenth aspect provides an apparatus for inspecting a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the apparatus comprising: a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; a conveyor configured to move the article in the first dimension through the first measurement area; and a computer including a processor and a memory; wherein the first profilometer is configured to: acquire a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; and transmit the first set of coordinate data of the first segment of the first measured cross-sectional profile to the computer; and wherein the computer is configured to: receive the first set of coordinate data of the first segment of the first measured cross-sectional profile; determine the first part of the surface of the article based, at least in part, on the first segment; generate a generated first part of the surface of the article using the determined first part of the surface; compare the determined first part of the surface and the generated first part of the surface and inspect the article based on a first result of the comparing.

An eleventh aspect provides a computer for inspecting, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the computer comprising a processor and a memory, wherein the computer is configured to: receive a first set of coordinate data of a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; receive the first set of coordinate data of the first segment of the first measured cross-sectional profile; determine the first part of the surface of the article based, at least in part, on the first segment; generate a generated first part of the surface of the article using the determined first part of the surface; compare the determined first part of the surface and the generated first part of the surface. and inspect the article based on a first result of the comparing.

A twelfth aspect provides a tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by computer device including at least a processor and a memory, cause the computer device to perform a method of inspecting, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method according to the ninth aspect.

Detailed Description of the Invention

According to the present invention there is provided a method, as set forth in the appended claims. Also provided is an apparatus, a computer and a tangible non-transient computer-readable storage medium. Other features of the invention will be apparent from the dependent

claims, and the description that follows.

First aspect The first aspect provides a method of determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method implemented, at least in part, by a computer including a processor and a memory, the method comprising: providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; moving, by a conveyor, the article in the first dimension through the first measurement area; acquiring, by the first profilometer, a first segment of a set of segments of a zeroth measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a zeroth part of the surface of the article; displacing the moving article by a first displacement of a set of displacements in the second and/or the third dimension; acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; correcting, by the computer, the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile; and determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected first segment.

In this way, correction for transverse (i.e. lateral) displacements of the moving article during the non-contact profilometry may be made, thereby enabling determination of the first part of the surface of the article and hence inspection thereof. Particularly, relative transverse displacements (i.e. in the second and/or the third dimension) between the zeroth measured cross-sectional profile and the first measured cross-sectional profile may be accounted for by the correcting, such that the first part of the surface of the article is determined using displacement-corrected coordinate data. Such relative transverse displacement typically arises due to vibration of the moving article, bodily movement thereof, for example falling or bouncing from and/or on the conveyor, and/or relative misalignment between the moving and the axial length of the article. As discussed below in more detail, a magnitude and/or a rate of the first displacement is such that conventional inspection of the moving article using non-contact profilometry is precluded.

Article The method is of determining the first part of the surface of the article having the axial length extending in the first dimension and the cross-sectional profile in mutually transverse second and third dimensions. It should be understood that the cross-sectional profile of the article is thus transverse to the axial length thereof, for example orthogonal thereto. It should be understood that the cross-sectional profile of the article may vary along the length, for example with respect to a design or target cross-sectional profile. In other words, the cross-sectional profile measured at a particular position along the axial length may deviate from the design cross-sectional profile and/or may differ with respect to that cross-sectional profile measured at an adjacent position. It should be understood that the surface of the article is the external surface (i.e. outwardly facing) of the article. It should be understood that the cross-sectional profile of the article is of the external surface of the article. That is, the method does not determine the cross-sectional profile due to internal surfaces, which are inaccessible to non-contact profilometry.

In one example, the article comprises and/or is a profile (also known as a section). In one example, the article comprises and/or is a steel profile. In one example, the article comprises and/or is a mechanically-processed profile or a thermomechanically-processed profile, for example a rolled, forged, extruded, drawn and/or rotary pierced, profile. In one example, the article comprises and/or is a mechanically-processed profile or thermomechanically-processed steel profile, for example a rolled steel profile, preferably a hot rolled steel profile.

In one example, the cross-sectional of the article includes one or more internal corners, for example, having angles of at most 90° or having angles of at least 900, such as formed by mechanical processing or thermomechanical processing. In one example, the cross-sectional profile of the article does not include opposed internal corners having angles of less than 90°.

Cross-sectional profiles having proposed internal corners having angles of less than 90° may not be formed by rolling.

In one example, the article has a length in a range from 1 m to 100 km, preferably in a range from 5 m to 1 km, more preferably in a range from 10 m to 250 m. That is, the article may be continuous or semi-continuous.

In one example the hot rolled steel profile has a unit mass of at least 20 kg/m, at least 20 kg/m, at least 30 kg/m, or at least 40 kg/m.

In one example, the hot rolled steel profile has a unit mass of at most 400 kg/m, at most 300 kg/m, or at most 270 kg/m, for example 260 kg/m.

In one example, the hot rolled steel profile has a symmetrical cross-section, having at least one line of symmetry. In one example, the hot rolled steel profile has an asymmetrical cross-section, having no lines of symmetry.

In one example, the hot rolled steel profile is formed by a rolling reduction ratio in a range from 2:1 to 50:1, preferably in a range from 3:1 to 27:1.

In one example, the hot rolled steel profile comprises carbon in a range from 0.01 wt.% to 0.9 wt.%, vanadium in a range from 0.001 wt.% to 1.2 wt.%, niobium in a range from 0.001 wt.% to 0.8 wt.% and/or boron in a range from 0.0001 wt.% to 0.004 wt.%, by weight percent of the steel.

In one example, the hot rolled steel profile is a bulb flat profile, a crane rail profile, a forklift profile, a track shoe profile, a cathode collector bar profile, a cutting edge profile, a top hat profile, a conveyor channel section, a bull wheel profile, a slider plate, a melting base iron product, a carriage stile, an angle, a cross-rail, a lug channel, a rolled billet or a tram profile.

Generally, bulb flats are used for plate stiffening, having widths in a range from 100 mm to 430 mm, thicknesses in a range from 7 mm to 20 mm and lengths in a range from 6 m to 18 m. Grades of steel for bulb flats include normal strength grades A, B, D and E and high strength grades A32, D32, E32, A36, D36 and E36. Grades of steel for bulb flats also include ASTM grade A572 Gr50, EN10025-2 grades S235JR+AR, S235J0+AR, S235J2+AR, S275JR+AR, S275J0+AR, S275J2+AR, S355JR+AR, S355J0+AR and S355J2+AR, EN10025-4 grade S355M and EN10225 grades Gil and G12. Bulb flats may be according to specifications defined by Lloyds Marine, RINA, American Bureau of Shipping, Bureau Veritas, DNV/GL and/or China Classification Society, for example.

Generally, crane rail is used for overhead gantry and floor-mounted cranes in ports, warehouses and shipyards. Grades of steel for crane rail may be according to DIN 536-1, for example 690, 880 and 90V, as shown in Table 2.

Grade wt.% C Si Mn P S V 690 Min 0.40 - 0.80 - - -Max 0.60 0.35 1.20 0.045 0.045 880 Min 0.60 - 0.80 - - - Max 0.80 0.50 1.30 0.045 0.045 - 90V Min 0.50 - 0.80 - - 0.06 Max 0.70 0.50 1.40 0.030 0.030 0.20 110CrV Min 0.05 - 0.50 - - -Max 0.50 1.00 1.30 0.30 0.30 1.00 Table 2: Compositions of steels for crane rail (ladle analysis) Generally, forklift profiles include profiles for mast assemblies, for example mast profiles (including U, I, J and offset J profiles), carriage (also known as hanger) bar profiles and flats for manufacturing fork arms.

Generally, track shoe profiles include single, double and triple grouser (spike) designs, having widths in a range from 170 mm to over 350 mm, for example to 390 mm or to 500 mm. Grades of steel for track shoe profiles include standard steels, for example boron-treated steels having a nominal carbon content of 0.2 to 0.4 wt.% and optionally Cr in a range from 0 to 0.50 wt.% such as C30CrO, C30Cr15, C30Cr50 and lower carbon steels, for example boron-treated steels having low sulphur (LS) and/or a lower carbon content of 0.25 wt.% and optionally Cr in a range from 0 to 0.75 wt.% such as C25Cr10, C25Cr40, C25Cr45-LS and C25Cr75-LS.

Generally, cathode collector bars have section widths in a range from 80 mm to 300 mm, for example from 122 mm to 279 mm, thicknesses in a range from 90 mm to 160 mm and cold-sawn lengths in a range from 0.3 m to 12 m, for example from 1.5 m to 10 m. Steel grades for cathode collector bars include ultra low carbon grades, having improved resistivity compared with other grades.

Generally, cutting edge profiles provide additional wear resistance and extended life for excavator bucket applications and include single bevel flats, double bevel flats, grader bars and arrowhead flats. Grades of steel for culling edge profiles include standard boron-treated steels having a nominal carbon content of 0.3 wt.% such as 8K-15-A, 8K-15-B and 8K-15-C and lower carbon boron-treated steels having a lower nominal carbon content of 0.25 wt.% such as SK1335K, SK1341K and SK1361K. Grades of steel for arrowhead flats include SKI 335K and 41B18M. Non-heat treated grades of steel for cutting edge profiles include SAE1572, SAE1084 and SAE1084.

Generally, mining profiles include tophat shaft guide sections for guiding cages and skips in mine shafts and conveyor channel sections used for manufacturing long wall or chain conveyors. Grades of steel for mining profiles include EN 10025-2: 2004 grades S275J0+AR, S355JR+AR and S355J2+AR, SANS grades 50025-2: 2009 8275J0+AR, S355JR+AR and S355J2+AR, CSA grades G40.21-04: 2004, 300W, 350W and 350VVT and AS/NZS 3679 1 grade 350.

Generally, bull wheel profiles may be used for bull wheels to drive cables, such as cables on ski-lifts or cablecars for example.

Generally, slider plates (also known as slide plates) are used to help telescopic movement often but not exclusively of steel booms e.g. in telehandlers. Feed slide plates are suitable for pushing uneaten feed on a feed table, for example.

Generally, melting base iron products, such as melting stock and high purity billet iron, are used for their high degree of chemical purity. Common examples of usage include rolling as billet form for addition to aerospace castings.

Generally, carriage stiles may be used as bracing in forkmasts.

Generally, angle (also known as steel angle) includes equal angle (EA) and unequal angle (EA). Equal angle typically has depths (or widths) of section in a range from 100 mm to 250 mm e.g. 120 mm, 150 mm or 200 mm, thicknesses in a range from 6 mm to 30 mm e.g. 8 mm, 10 mm, 12 mm, 15 mm, 16 mm, 18 mm, 20 mm or 24 mm and lengths in a range from 6 m to 18 m. Equal angle examples include 120 x 120 x 10, 120 x 120 x 12, 120 x 120 x15, 120 x 120 x 8, 150 x 150 x10, 150 x 150 x 12, 150 x 150 x 15, 150 x 150 x 18, 200 x 200 x 16, 200 x 200 x 18, 200 x 200 x 20 and 200 x 200 x 24 (dimensions in mm). Unequal angle typically has depths of section in a range from 100 mm to 250 mm e.g. 100 mm, 150 mm or 200 mm, widths of section in a range from 100 mm to 250 mm e.g. 100 mm, 150 mm or 200 mm, thicknesses in a range from 8 mm to 20 mm e.g. 10 mm, 12 mm, 15 mm or 18 mm and lengths in a range from 6 m to 18 m. Unequal angle examples include 200 x 100 x 10, 200 x 100 x 12, 200 x 100 x 15, 200 x 150 x 12, 200 x 150 x 15 and 200 x 150 x 18 (dimensions in mm) Generally, cross-rails are used to support the movement of small cranes in mobile equipment such as the rear of backhoe loaders.

Generally, lug channels are used in various ways, typically around support mechanisms for material handling systems.

In one example, the hot rolled steel profile has a surface quality index of at least 6, preferably at least 7, more preferably at least 8.

The surface quality index may be defined according to a proportion, a distribution and a size of surface defects (also known as discontinuities) of the hot rolled steel profile, as shown in Table 1. Rolled in scale may result in surface defects including 'snake skin effect', 'tiger scale', 'salt and pepper', 'drag or comet' and/or banding defects.

Surface quality Area of surface defects as a percentage of total surface Distribution of Depth of surface Comments index area surface defects defects At most 0.1% Uniform At most 0.2 mm No scale marks 9 At most 1% Uniform At most 0.2 mm 8 At most 2% Uniform At most 0.3 mm 7 At most 3.5% Uniform At most 0.3 mm 6 At most 5% Uniform At most 0.3 mm At most 7.5% Uniform At most 0.3 mm 4 At most 10% Uniform At most 0.5 mm 3 At most 15% Uniform At most 0.5 mm 2 At most 20% Uniform At most 0.5 mm 1 More than 20% Uniform At most 0.5 mm 0 More than 5% Banding At most 0.5 mm Table 1: Surface quality index Computer The method is implemented, at least in part, by the computer including the processor and the memory. Processor and/or memory requirements, particularly for in-process (i.e. in situ, online, real-time) determinations, may be defined, at least in part, by a rate of receiving and/or a size of the coordinate data, as understood by the skilled person.

Non-contact profilometry The method comprises providing the set of non-contact profilometers including the first profilometer, for example the first optical profilometer, defining the first measurement area.

Generally, a profilometer is a measuring instrument used to measure a surface's profile, in order to determine the surface topography, for example to quantify roughness. Dimensions such as step, curvature and/or flatness may be computed from the surface topography. During profilometry using a contact-profilometer, a stylus contacts the surface while moving therealong, allowing measurement of surface features in the range from 10 nm to 1 mm. While contact profilometry allows direct measurement of the surface features and thus is tolerant to surface debris, even the upper end of the range of 1 mm is one, two or more orders of magnitude smaller than typical displacements of the profile while a speed of the moving of the article is incompatible with contact profilometry.

In contrast, non-contact profilometers, for example optical profilometers, provide non-contact measurement of surface features. Non-contact profilometry includes laser triangulation (triangulation sensor), confocal microscopy (used for profiling of very small objects), low coherence interferometry and digital holography. Generally, advantages of optical profilometry include speed, reliability and spot size. Optical fibre-based optical profilometers scan surfaces using optical probes: light interference signals are sent back to the profilometer detector via an optical fibre. Fibre-based probes may be physically located hundreds of meters away from the detector enclosure, without signal degradation. Further advantages of fibre-based probes include flexibility, long profile acquisition, ruggedness, and ease of incorporating into industrial processes.

In one example, the first profilometer comprises and/or is a first optical profilometer. In one example, the first optical profilometer comprises and/or is a triangulation sensor.

Triangulation is based on detecting changes of a position of a focused laser beam. The laser beam is incident on a surface of the article at an acute angle, so that changes of elevation of the surface are transformed into changes of position of the reflected laser beam at a position-sensitive detector. Autocollimators are typically used. Triangulation is suitable for profilometry of large areas, including curved and irregular surfaces. For relatively smooth surfaces, optimized triangulation can achieve lateral resolutions better than 0.1 pm. However, since a change of reflected position is ascribed to a change in elevation of the surface, displacement (i.e. movement) of the article and hence the surface towards or away from the laser and/or detector results in artefacts in the measured surface. For example, displacement of the article and hence the surface towards the laser and/or detector results in an apparent convexity of, such as a protrusion on, the surface. Conversely, displacement of the article and hence the surface away the laser and/or detector results in an apparent concavity of, such as a depression in, the surface. For example, vibration of the article transverse to the laser and/or detector would result in a flat surface thereof determined to be undulating. For example, bodily drop of the article transverse to the laser and/or detector would result in a flat surface thereof determined to be concave. Thus, both horizontal and vertical movements of the article (i.e. displacements in the second and the third dimension) result in artefacts. Similarly, axial rotation of the article may result in respective parts of the surface being displaced towards and away from the laser and/or detector. Furthermore, diffuse scattering from the surface, such that the reflected beam is not clean, results in artefacts in the measured surface. More generally, non-contact profilometry is similarly limited by such artefacts since non-contact profilometry is based on measuring changes in relative distance to the surface of the article.

Such artefacts conventionally preclude use of non-contact profilometry in applications where such displacement cannot be controlled to below a limit of resolution of the non-contact profilometry and/or below a limit of interest of the surface of the article (for example, a permitted tolerance). For example, laboratory and metrology uses of non-contact profilometry require accurate and precise control of movement of the article or non-contact profilometry sensor, for example using a machine bed or x-y gantry. Industrial applications require control of such displacement such that measurements are within permitted tolerances. For example, non-contact profilometry, using triangulation, of extruded rubber profiles requires controlled conveying, on a conveyor, of the rubber profiles. For example, non-contact profilometry, using triangulation, of seam inspection of welded pipe seams requires use of shaped rollers to constrain movement of the pipe such that only weld defects are measured. For example, in situ non-contact profilometry, using triangulation, of rail head defects of rail, installed on a railway line, requires sufficiently accurate and precise control of a predetermined separation between the rail and the laser and detector, mounted on-board a moving carriage, for example using a follower wheel that contacts the rail and maintains the predetermined separation. For example, non-contact profilometry, using triangulation, of logs to determine optimum sawing thereof at a sawmill requires controlled conveying, on guide rails, of the logs yet still results in an error of up to 8 mm, though sufficiently acceptable for sawing.

However, the method according to the first aspect corrects for such translation, extending the use of non-contact profilometry to applications where articles are subject to, for example, unavoidable movements thereof and/or where control of displacement is not possible and/or practical, for example by physically constraining the articles by contacting the articles with guides. Particularly, an advantage of non-contact profilometry is that it is non-contact. If contact of the articles is required, so as to use non-contact profilometry, this advantage is negated.

The first profilometer defines the first measurement area, as understood by the skilled person.

Typically, measurement areas are defined using x, y axes with elevation in the z axis.

Typically, in use, the first dimension is substantially aligned (for example within ±10°) with the x axis, such the second dimension may be defined to substantially correspond with the y axis and the third dimension may be defined to substantially correspond with the z axis. In one example, the first profilometer has a measurement range in the z axis in a range from 50 mm to 1000 mm, preferably in a range from 100 mm to 900 mm, for example 60 mm, 130 mm, 260 mm, 520 mm or 800 mm. In one example, the first profilometer has a resolution in the z axis in a range from 1 pm to 200 pm, preferably in a range from 2 pm to 100 pm, for example 2 pm, 3.2 pm, 4.9 pm, 9.6 pm, 14 pm, 17.8 pm, 22 pm, 28 pm, 43 pm, or 67 pm. In one example, the first profilometer has a measurement range in the x axis in a range from 10 mm to 1000 mm, preferably in a range from 200 mm to 800 mm, for example 30 mm, 50 mm, 52 mm, 110 mm, 150 mm, 230 mm, 285 mm, 450 mm, 455 mm or 720 mm. In one example, the first profilometer has a resolution in the x axis in a range from 1 pm to 500 pm, preferably in a range from 10 pm to 200 pm, for example 17 pm, 26 pm, 55 pm, 79 pm, 120 pm, 151 pm, 235 pm, 238 pm or 361 pm. The measurement range in the y axis and/or the resolution in the y axis may be as described with respect to the measurement range in the x axis and/or the resolution in the x axis, respectively. Generally, increasing the measurement range is accompanied by a decrease in the resolution. Hence, the measurement range may be selected, for example optimised or minimised, according to a size of the article and/or a magnitude of the displacements thereof.

Suitable non-contact profilometers, particularly optical non-contact profilometers using triangulation, are available from KEYENCE (UK) Ltd such as LJ-X8000 Series, LJ-V7000 Series, LF-G5000 Series, LJ-G5000 Series and wenglor sensoric GmbH such as weCat3D MLSL1, MLSL2, MLWL1, MLWL2, for example. Other non-contact profilometers are known.

In one example the set of non-contact profilometers includes N non-contact profilometers including the first profilometer, wherein N is a natural number greater than or equal to 1, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more, for example arranged, at least in part, mutually spaced apart, for example equispaced, in the second and/or third dimensions, on the locus of a circle such as substantially circumferentially around the cross-sectional profile and/or arranged in the same plane (i.e. such that the respective measurement areas are coplanar) in the second and/or third dimensions. By increasing the number N of non-contact profilometers, the number of segments and/or their respective positions, of the measured cross-sectional profile, may be increased enabling a greater proportion of the cross-sectional profile to be measured, for example the complete cross-sectional profile. Additionally and/or alternatively, by increasing the number N of non-contact profilometers, overlap between adjacent segments may be increased, thereby increasing resolution and/or reducing errors of the cross-sectional profile in the overlap. In one example, the set of non-contact profilometers includes NCP non-contact profilometers including the first profilometer, wherein NCP is a natural number greater than or equal to 2, for example 2, 3, 4, 5, 6, 7, 8, 9, 10 or more, for example arranged, at least in part, mutually spaced apart in the second and/or third dimensions, for example circumferentially around the cross-sectional profile, for measuring at least 70% , preferably at least 80%, more preferably at least 90%, even more preferably at least 95%, most preferably at least 97.5% of the cross-sectional profile, by a perimeter thereof In one example, providing the set of non-contact profilometers comprises providing the set of non-contact profilometers including a second profilometer, for example a second optical profilometer, defining a second measurement area; and the method comprises: acquiring, by the second profilometer, a second segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the second measurement area, wherein the second segment comprises a second set of coordinate data, in the second and the third dimensions, of a second part of the surface of the article; transmitting, by the second profilometer, the second set of coordinate data of the second segment to the computer; receiving, by the computer, the second set of coordinate data of the second segment; correcting, by the computer, the second segment for the first displacement, thereby providing a corrected second segment comprising a second set of corrected coordinate data; and determining, by the computer, the second part of the surface of the article based, at least in part, on the corrected second segment.

In this way, a greater proportion of the cross-sectional profile may be measured, for example the complete cross-sectional profile.

In one example, providing the set of non-contact profilometers comprises providing the set of non-contact profilometers including a second profilometer, for example a second optical profilometer, defining a second measurement area; and the method comprises: acquiring, by the second profilometer, a second segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the second measurement area, wherein the second segment comprises a second set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; transmitting, by the second profilometer, the second set of coordinate data of the second segment to the computer; receiving, by the computer, the second set of coordinate data of the second segment; correcting, by the computer, the second segment for the first displacement, thereby providing a corrected second segment comprising a second set of corrected coordinate data; and determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected second segment.

In this way, overlap between adjacent segments (i.e. the first segment and the second segment) increases resolution and/or reduces errors of the cross-sectional profile in the overlap.

In one example, correcting the second segment for the first displacement comprises correcting the second segment for the first displacement using the first correction. That is, the first correction may be applied to the first segment and the second segment. In this way, computation may be accelerated. Correcting the second segment may be as described with respect to correcting the first segment, mutafis mutandis.

Moving the article The method comprises moving, by the conveyor, the article in the first dimension through the first measurement area. It should be understood that the article is moved relative to the first measurement area. More generally, in one example, the method comprises moving the article in the first dimension relative to and through the first measurement area. It should be understood that in the method according to the first aspect, the set of non-contact profilometers and hence the first measurement area is static (i.e. not moving) while the article is moved by the conveyor. However, as understood by the skilled person, the method is applicable, mutatis mutandis, where the set of non-contact profilometers and hence the first measurement area is moving while the article is static and/or where both the set of non-contact profilometers and hence the first measurement area and the article are moving (provided that there is relative movement). Hence, in one alternative example, the method comprises moving the first measurement area, for example by moving the set of non-contact profilometers relative to the article, in the first dimension over the article. In one example, the conveyor comprises and/or is a wheel conveyor; a roller conveyor such as gravity roller conveyor, an unpowered roller conveyor or a powered (also known as live) roller conveyor; a chain conveyor; a slat conveyor; and/or a belt conveyor such as a flat belt conveyor, a magnetic belt conveyor or a troughed belt conveyor. In one preferred example, the conveyor comprises and/or is an unpowered roller conveyor. In this way, relatively massive articles may be moved thereby and/or are robust to dynamic loadings, appropriate for industrial applications such as manufacturing of semi-continuous articles.

In one example, moving the article in the first dimension through the first measurement area comprises moving the article in the first dimension through the first measurement area at a speed, for example a velocity, in a range from 0.01 ms to 100 ms-1, in a range from 0.1 ms-1 to 10 ms-1, preferably in a range from 0.5 ms-1 to 5 ms-1, more preferably in a range from 1 ms-' to 2.5 ms-1. Such speeds thus correspond to even 3.6 km h-1 to 9 km for the more preferable range, appropriate for industrial applications such as manufacturing of semi-continuous articles. In one example, moving the article in the first dimension through the first measurement area comprises controlling the moving, for example by controlling a speed of the conveyor, for example by the conveyor and/or a controller thereof such as the computer.

In one example, moving the article in the first dimension through the first measurement area comprises moving the article in the first dimension through the first measurement area continuously or intermittently, preferably continuously. It should be understood that the article is generally moved between acquiring each measured cross-sectional profile of the set of measured cross-sectional profiles, for example by a substantially constant distance in the first dimension. In this way, successive measured cross-sectional profiles are regularly spaced. It should be understood that the article may be moving during the acquiring, for example if the article is moving continuously.

Acquiring the first segment of the zeroth measured cross-sectional profile The method comprises acquiring, by the first profilometer, the first segment of the set of segments of the zeroth measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises the first set of coordinate data, in the second and the third dimensions, of the zeroth part of the surface of the article.

It should be understood that the first segment corresponds with a portion of the cross-sectional profile, for example subtending an angle of a locus or perimeter thereof. In one example, the first segment subtends an angle in a range from 15° to 180°, preferably in a range from 30° to 150°, more preferably in a range from 45° to 135°, for example 60°, 90° or 120°. For example, if the set of non-contact profilometers includes 6 mutually spaced, preferably equispaced profilometers, such that each respective segment subtends a non-overlapped angle of at least 60°, the complete cross-sectional profile of the article may be measured. Similarly, if the set of non-contact profilometers includes 3 mutually spaced, preferably equispaced profilometers, such that each respective segment subtends a non-overlapped angle of at least 120°, the complete cross-sectional profile of the article may be measured.

It should be understood that the zeroth measured cross-sectional profile is a reference measured cross-sectional profile and may be an initial or a subsequent measured cross- sectional profile. That is, the zeroth measured cross-sectional profile is relative to the first measured cross-sectional profile and is this measured therebefore. In one example, the zeroth measured cross-sectional profile and the first measured cross-sectional profile are successive. In one example, the zeroth measured cross-sectional profile and the first measured cross-sectional profile are adjacent. In one example, the zeroth measured cross-sectional profile precedes the first measured cross-sectional profile. In one preferred example, the zeroth measured cross-sectional profile directly precedes the first measured cross-sectional profile (i.e. the zeroth measured cross-sectional profile and the first measured cross-sectional profile are directly adjacent, without any other measured cross-sectional profiles therebetween). In one example, the set of measured cross-sectional profiles includes CSP measured cross-sectional profiles including the zeroth measured cross-sectional profile and the first measured cross-sectional profile, wherein CSP is a natural number greater than or equal to 2, for example 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000, 100000, 200000, 500000, 1000000, 2000000, 5000000, 10000000, 20000000, 50000000 or more. That is, the number CSP of measured cross-sectional profile may be unlimited, for example defined by the axial length of the article and a spacing between adjacent measured cross-sectional profiles. In one example, the set of measured cross-sectional profiles includes CSP measured cross-sectional profiles including the zeroth measured cross-sectional profile and the first measured cross-sectional profile, wherein CSP is calculated from based on a length of the article and a spacing between adjacent measured cross-sectional profiles. In one example, the spacing (i.e. in the first dimension or x axis) is calculated based on a speed of moving the article in the first dimension and a measurement frequency of the set of non-contact profilometers, for example the first profilometer. In one example, a measurement frequency of the set of non-contact profilometers, for example the first profilometer, is in a range from 10 Hz to 1 MHz, preferably in a range from 100 Hz to 100 kHz, more preferably in a range from 1 kHz to 10 kHz, for example 6 kHz. In this way, if the measurement frequency is 5 kHz and the article is moving at a speed of 1 ms-1, for example, the spacing between adjacent measured cross-sectional profiles (and hence effective resolution in the first dimension or x axis) is 0.2 mm. Increasing the measurement frequency and/or reducing the speed improves this effective resolution. Conversely, to increase speed while maintain this effective resolution, the measurement frequency must be increased. The measurement frequency and/or the speed may be selected according to a desired effective resolution in the first dimension or x axis whilst considering a data and/or computation rate.

The first segment comprises the first set of coordinate data, in the second and the third dimensions (i.e. the y and z axes, respectively), of the zeroth part of the surface of the article. It should be understood that coordinate data of the first set of coordinate data in the first dimension (or the x axis) may be assigned thereto, for example by the first profilometer, for example based on a measurement frequency thereof. It should be understood that the zeroth part of the surface of the article is a reference part of the surface of the article and may be an initial or a subsequent part of the surface of the article. That is, the zeroth part of the surface of the article is relative to the first part of the surface of the article and is this measured therebefore. In one example, the zeroth part of the surface of the article and the first part of the surface of the article are successive. In one example, the zeroth part of the surface of the article and the first part of the surface of the article are adjacent. In one example, the zeroth part of the surface of the article precedes the first part of the surface of the article. In one preferred example, the zeroth part of the surface of the article directly precedes the first measured part of the surface of the article (i.e. the zeroth part of the surface of the article and the first part of the surface of the article are directly adjacent, without any other measured parts of the surface of the article therebetween). In one example, the zeroth part of the surface of the article is represented by a line in the second and/or third dimensions. In one example, the first set of coordinate data defines a line, for example a first line, in the second and/or third dimensions, for example only in the in the second and/or third dimensions. That is, the surface of the article may be represented by one or more lines or parts thereof, around, preferably completely around, the cross-sectional profile of the article, with a series thereof extending, for example intermittently and/or regularly, along the axial length, as understood by the skilled person. Data rates for non-contact profilometry, using triangulation, may be in a range from 105 to 108 data points per second or more. For example, for a measurement frequency of 6 kHz and a data rate of 1.2 x 107 data points per second, each set of coordinate data, in the second and the third dimensions, may include 2000 data points.

Displacing the moving article The method comprises displacing the moving article by the first displacement of the set of displacements in the second and/or the third dimension. It should be understood that the moving article is displaced by the first displacement after acquiring, by the first profilometer, the first segment of the zeroth measured cross-sectional profile and before acquiring, by the first profilometer, the first segment of the first measured cross-sectional profile. In other words, the first displacement of the moving article, in the second and/or the third dimension, between acquiring of the zeroth measured cross-sectional profile and the first measured cross-sectional profile i.e. in a time period therebetween. For example, if a measurement frequency of the first profilometer is 5 kHz, the time period between successive acquisitions is 0.2 ms. More generally, the article may be displaced by respective displacements between successive acquisitions of respective measured cross-sectional profiles. It should be understood that the article may be continuously and/or intermittently displaced, including while acquiring, by the first profilometer, the first segment of the zeroth measured cross-sectional profile and/or while acquiring, by the first profilometer, the first segment of the first measured cross-sectional profile. In one example, the set of displacements includes D displacements including the first displacement, wherein D is a natural number greater than or equal to 1, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. In one example, the set of displacements includes the first displacement and a second displacement, corresponding with the second dimension and the third dimension and/or the y axis and z axis respectively, wherein a net displacement of the article is resolved into first displacement and the second displacement along these dimensions and/or axes. It should be understood that the first displacement may be positive, for example towards the first profilometer, or negative, for example away from the profilometer.

In one example, displacing the moving article by the first displacement of the set of displacements in the second and/or the third dimension comprises displacing the moving article by the first displacement of the set of displacements in the second and/or the third dimension, wherein the first displacement (i.e. a magnitude thereof) is in a range from 0.01 mm to 100 mm, preferably in a range from 0.1 mm to 10 mm, more preferably in a range from 0.5 mm to 5 mm. That is, the first displacement may be relatively large, for example compared with a resolution of the first profilometer and/or a tolerance of the article. It should be understood that the first displacement of the moving article, in the second and/or the third dimension, is in a time period between acquiring of the zeroth measured cross-sectional profile and the first measured cross-sectional profile. For example, if the first displacement is 1 mm and a measurement frequency of the first profilometer is 5 kHz, the time period between successive acquisitions is 0.2 ms such that a speed of the displacing, in the second and/or the third dimension, is 5 ms-1. In one example, displacing the moving article by the first displacement is uncontrolled (i.e. not deliberate, not predetermined, accidental, undesired) notwithstanding that the first displacement may arise from an external force on the article, such as due to gravity during dropping the article on the conveyor, a collision of the article with another object and/or vibrations and/or bounce of the article on the conveyor.

In one example, displacing the moving article by the first displacement of the set of displacements in the second and/or the third dimension comprises displacing the moving article by the first displacement of the set of displacements in the second and/or the third dimension at a speed for example a velocity, in a range from 0.1 ms-1 to 10 ms-1, preferably in a range from 0.5 ms-1 to 5 ms-1, more preferably in a range from 1 ms-1 to 2.5 ms-1. That is, the speed of the first displacement may be relatively large compared with, for example, a measurement frequency of the first profilometer and/or may be substantially similar to a speed of moving the article in the first dimension. A speed of moving the article may be controlled, for example by the conveyor and/or a controller thereof such as the computer. In contrast, a speed and/or a magnitude of the first displacement may be uncontrolled or relatively uncontrolled, for example due to vibrations, bounce and/or dropping the article on the conveyor, as discussed previously.

In one example, displacing the moving article by the first displacement of the set of displacements in the second and/or the third dimension comprises deforming (for example elastically), at least in part, the moving article by the first displacement of the set of displacements in the second and/or the third dimension. That is, the article may be deformed, for example transiently (i.e. elastically) while moving, such as due to vibrations, bounce and/or dropping the article on the conveyor, as discussed previously.

In one example, the method comprises: displacing the moving article by a second displacement of the set of displacements in the second and/or the third dimension; acquiring, by the first profilometer, a first segment of a set of segments of a second measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a second part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the second measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the second measured cross-sectional profile; correcting, by the computer, the first segment for the second displacement by a second correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the second measured cross-sectional profile; and determining, by the computer, the second part of the surface of the article based, at least in part, on the corrected first segment.

In this way, respective displacements as the article, for example a part of the axial length thereof or the whole axial length thereof, is moved through the first measurement area may be corrected for. In this way, the surface of the article may be determined in the absence of displacement, thereby allowing inspection of surface features of the article at a relatively higher resolution than otherwise possible without correction.

Acquiring the first segment of the first measured cross-sectional profile The method comprises acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area. Acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area may be as described with respect to acquiring, by the first profilometer, the first segment of the set of segments of the zeroth measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the first measurement area, mutatis mutandis.

The first segment comprises the first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article. The first segment comprising the first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article may be as described with respect to the first segment comprising the first set of coordinate data, in the second and the third dimensions, of the zeroth part of the surface of the article, mutafis mutandis.

Transmitting and receiving The method comprises transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile.

The method comprises receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile.

That is, the first profilometer and the computer are mutually communicatively coupled, for example unidirectionally or bidirectionally. In one example, transmitting and/or receiving comprise wirelessly transmitting and/or receiving, respectively. In this way, the first profilometer and the computer may be situated remotely. However, for some industrial applications, wireless transmission and/or reception may not be possible, for example due to buildings and/or wireless interference. In one example, transmitting and/or receiving comprise wired transmitting and/or receiving, respectively.

Correcting for the displacement The method comprises correcting, by the computer, the first segment for the first displacement by the first correction, thereby providing the corrected first segment comprising the first set of corrected coordinate data of the first measured cross-sectional profile. In this way, the first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article is corrected for the first displacement, such that the first part of the surface is substantially invariant, preferably invariant, with respect to the zeroth part of the surface in the second and the third dimensions, notwithstanding moving in the first dimension and inherent differences between the zeroth part of the surface and the first part of the surface. In other words, the first displacement is accounted or compensated for, thereby improving measurement of the surface of the article and hence a more accurate and/or precise representation of the surface.

In one example, correcting the first measured cross-sectional profile for the first displacement by the first correction comprises correcting the first measured cross-sectional profile for the first displacement by the first correction relative to the zeroth measured cross-sectional profile. That is, the zeroth measured cross-sectional profile provides a reference for the correction. More generally, in one example, correcting a measured cross-sectional profile for a respective displacement by a respective correction comprises correcting the measured cross-sectional profile relative to a preceding measured cross-sectional profile, for example the zeroth measured cross-sectional profile, a reference measured cross-sectional profile and/or an adjacent measured cross-sectional profile.

In one example, correcting the first measured cross-sectional profile for the first displacement by the first correction comprises identifying coordinate data representing a first substantially linear or linear portion of the first part of the surface of the article by comparing first and second coordinate data of the first set of coordinate data. In this way, the first substantially linear or linear portion provides a reference portion that may be mapped, for example, to a datum (i.e. a predetermined reference) and/or to which remaining coordinate data of the first set of coordinate data may be referenced.

In one example, correcting the first measured cross-sectional profile for the first displacement by the first correction comprises rotating coordinate data of the first set of coordinate data about the first dimension by a first rotation of a set of rotations, wherein the first set of corrected coordinate data comprise rotated coordinated data. In this way, the coordinate data are transformed, for example so as to align with a first datum (i.e. a predetermined reference). In this way, the coordinate data are corrected for a rotational component of the first displacement. In one example, correcting the first measured cross-sectional profile for the first displacement by the first correction comprises identifying coordinate data representing a first substantially linear or linear portion of the first part of the surface of the article by comparing first and second coordinate data of the first set of coordinate data and rotating coordinate data of the first set of coordinate data about the first dimension by a first rotation of a set of rotations wherein the rotated first substantially linear or linear portion corresponds (for example aligns with, maps to) a first datum. In one example, the first datum is predetermined and/or is obtained from the zeroth measured cross-sectional profile, for example.

In one example, correcting the first measured cross-sectional profile for the first displacement by the first correction comprises translating coordinate data of the first set of coordinate data in the second and/or the third dimension by a first translation of a set of translations, wherein the first set of corrected coordinate data comprise translated coordinated data. In this way, the coordinate data may be transformed to a reference origin, for example. In this way, the coordinate data are transformed, for example so as to align with a second datum (i.e. a predetermined reference). In this way, the coordinate data are corrected for a translational component of the first displacement. In one example, correcting the first measured cross-sectional profile for the first displacement by the first correction comprises identifying coordinate data representing an end of the first part of the surface of the article and translating coordinate data of the first set of coordinate data to correspond with (for example align with, map to) a second datum, for example an origin. In one example, the second datum is predetermined and/or obtained from the zeroth measured cross-sectional profile.

In one example, the method comprises discovering the segments of the set of segments of the first measured cross-sectional profile by extracting an identifier, for example a time stamp, associated with the first set of coordinate data and selecting segments having the same, corresponding and/or adjacent identifiers, for example the same time stamp within a time range. In this way, the coordinate data from the different profilometers may be aligned, for example temporarily, so as to relate to the same measured cross-sectional profile.

In one example, correcting the first measured cross-sectional profile for the first displacement by the first correction comprises nominating the first profilometer as a reference first profilometer and correcting respective segments acquired by the remaining profilometers of the set of profilometers based on the first correction, for example by the first rotation and/or the first translation i.e. the same correction is applied to all coordinate data acquired by the set of profilometers for a particular measured cross-sectional profile. However, different corrections may be required for different measured cross-sectional profiles, since displacements thereof may be different.

Determining the first part of the surface of the article The method comprises determining, by the computer, the first pad of the surface of the article based, at least in pad, on the corrected first segment. In this way, by determining the first pad of the surface of the article based, at least in part, on the corrected first segment, a more accurate and/or precise representation of the surface is provided. In this way, the advantages of non-contact profilometry may be realised in applications where displacements cannot be controlled to below a limit of resolution of the non-contact profilometry and/or below a limit of interest of the surface of the article (for example, a permitted tolerance). In this way, the surface of the article may be determined in the absence of displacement, thereby allowing inspection of surface features of the article at a relatively higher resolution than otherwise possible without correction. It should be understood that the determined first part of the surface of the article is thus the measured surface, based, at least in part on the corrected first segment. More generally, the determined first part of the surface is thus a part of the measured surface of the article, after any correction thereto. Hence, the determined first part of the surface may be represented by a series of points and/or by a line in one or two dimensions, corresponding with at least a part of the cross-sectional profile of the article. By similarly determining other parts of the surface using the coordinate data from the set of segments and aggregating or combining these determined parts of the surface, the whole of the cross-sectional profile of the article may be represented by a series of points and/or by a line in two dimensions, which may be termed a slice, for example.

It should be understood that successive parts of the surface of the article may be determined similarly. That is, the article may be represented by a sequence of slices i.e. the whole of the profile of the article may be represented by a series of points and/or by lines in three dimensions, thereby allowing three-dimensional visualisation of the article.

In one example, the method comprises determining a set of parts, including the first part, of the surface of the article, for each part of the set of parts, as described with respect to the first part.

In this way, the surface, for example, the whole surface of the article may be determined.

In one example, the method comprises repeating the acquiring, the transmitting, the receiving, the correcting and/or the determining for each measured cross-sectional profile of the set of measured cross-sectional profiles, for example for the whole axial length of the article. In this way, the whole surface of the article may be determined.

In one example, the method comprises aggregating the set of measured cross-sectional profiles and/or the determined surfaces thereof. In this way, the whole surface of the article may be represented, for example graphically, and/or analysed.

In one example, the method comprises detecting an end, for example both ends, of the article. In this way, the surface is determined only of the article. In one example, the method comprises rejecting false triggers and/or gaps. In this way, erroneous measurements are reduced.

In one example, the method comprises sensing a speed and/or a length of the article. In this way, positions along the length of the article may be determined. In one example, the method comprises determining a position along the length of the article based, at least in part, on a scan number and/or scan frequency of the first segment.

In one example, the method comprises recognising, for example using image analysis, a serial number included in the surface of the article. For example, a serial number may be stamped, engraved or etched into the surface of the article and this serial number may be recognised. In this way, the data and the determined surface of the article may be associated with the serial number, for example automatically.

Processing In one example, the method comprises processing (i.e. manufacturing, forming) the article, for example mechanical and/or thermomechanical processing of the article before moving, for example directly, by the conveyor, the article in the first dimension through the first measurement area. That is, the method of determining the first part of the surface of the article is integrated directly with processing the article. In one example, the mechanical and/or thermomechanical processing of the article comprises rolling, forging, extrusion, drawing and/or rotary piercing. In one example, the mechanical and/or thermomechanical processing of the article comprises finish processing of the article, for example straightening.

Second aspect The second aspect provides an apparatus for determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the apparatus comprising: a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; a conveyor configured to move the article in the first dimension through the first measurement area; and a computer including a processor and a memory; wherein the first profilometer is configured to: acquire a first segment of a set of segments of a zeroth measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a zeroth part of the surface of the article; acquire a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article, wherein the moving article is displaced by a first displacement of a set of displacements in the second and/or the third dimension; and transmit the first set of coordinate data of the first segment of the first measured cross-sectional profile to the computer; and wherein the computer is configured to: receive the first set of coordinate data of the first segment of the first measured cross-sectional profile; correct the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile; and determine the first part of the surface of the article based, at least in part, on the corrected first segment.

The first pad of the surface, the article, the axial length, the first dimension, the cross-sectional profile, the mutually transverse second and third dimensions, the set of non-contact profilometers, the first profilometer, the first optical profilometer, the first measurement area, the first segment of the set of segments of the zeroth measured cross-sectional profile, the set of measured cross-sectional profiles, the moving article, the first set of coordinate data of the zeroth part of the surface of the article, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, the first segment, the first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article, the first displacement, the set of displacements, the first correction, the corrected first segment comprising the first set of corrected coordinate data of the first measured cross-sectional profile and/or the first part of the surface of the article may be as described with respect to the first aspect.

The apparatus may be configured to implement the method, for example any step thereof, according to the first aspect.

Third aspect The third aspect provides a computer for determining, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the computer comprising a processor and a memory, wherein the computer is configured to: receive a first set of coordinate data of a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article, wherein the moving article is displaced by a first displacement of a set of displacements in the second and/or the third dimension; correct the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile; and determine the first part of the surface of the article based, at least in part, on the corrected first segment.

The computer may be configured to implement the method, for example any step thereof, according to the first aspect.

Fourth aspect The fourth aspect provides a tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by computer device including at least a processor and a memory, cause the computer device to perform a method of determining, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method according to the first aspect.

Fifth aspect The fifth aspect provides a method of determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method implemented, at least in part, by a computer including a processor and a memory, the method comprising: providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; moving, by a conveyor, the article in the first dimension through the first measurement area; occluding, at least in part, the first part of the surface of the moving article by a first occlusion in the first measurement area; acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the occluded, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a first part of a surface of the first occlusion; transmitting, by the first profilometer, the first set of coordinate data of the first segment to the computer; receiving, by the computer, the first set of coordinate data of the first segment; correcting, by the computer, the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data; and determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected first segment.

The first part of the surface, the article, the axial length, the first dimension, the cross-sectional profile, the mutually transverse second and third dimensions, the set of non-contact profilometers, the first profilometer, the first optical profilometer, the first measurement area, the first segment of the set of segments of the first measured cross-sectional profile, the set of measured cross-sectional profiles, the moving article, the conveyor, the first segment, the first set of coordinate data, the first part of the surface of the article, the first correction, the corrected first segment comprising the first set of corrected coordinate data of the first measured cross-sectional profile and/or the first part of the surface of the article may be as described with respect to the first aspect, mutatis mutandis.

The method according to the fifth aspect may include the method, for example any step thereof, according to the first aspect. Particularly, it should be understood that the method according to the fifth aspect may include correcting, by the computer, the first segment for a first displacement by a first correction, as described with respect to the first aspect. Similarly, it should be understood that the method according to the first aspect may include correcting, by the computer, the first segment for the first occlusion, as described with respect to the fifth aspect.

The steps of providing the set of non-contact profilometers, moving, by the conveyor, the article, acquiring, by the first profilometer, the first segment, transmitting, by the first profilometer, the first set of coordinate data and/or receiving, by the computer, the first set of coordinate data maybe as described with respect to the first aspect, mutafis mutandis, and will not be repeated for brevity.

Article The method is of determining the first part of the surface of the article having the axial length extending in the first dimension and the cross-sectional profile in mutually transverse second and third dimensions, as described with respect to the first aspect, mutatis mutandis.

Computer The method is implemented, at least in part, by the computer including the processor and the memory, as described with respect to the first aspect, mutatis mutandis.

Non-contact profilometty The method comprises providing the set of non-contact profilometers including the first profilometer, for example the first optical profilometer, defining the first measurement area, as described with respect to the first aspect, mutatis mutandis.

In one example,

providing the set of non-contact profilometers comprises providing the set of non-contact profilometers including a second profilometer, for example a second optical profilometer, defining a second measurement area; and the method comprises: acquiring, by the second profilometer, a second segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the occluded, moving article in the second measurement area, wherein the second segment comprises a second set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a second part of the surface of the first occlusion; transmitting, by the second profilometer, the second set of coordinate data of the second segment to the computer; receiving, by the computer, the second set of coordinate data of the second segment; correcting, by the computer, the second segment for the first occlusion, thereby providing a corrected second segment comprising a second set of corrected coordinate data; and determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected second segment.

In one example, correcting the first segment for the first occlusion comprises identifying coordinate data of the first part of the surface of the first occlusion by comparing first and second coordinate data of the first set of coordinate data and by comparing first and second coordinate data of the second set of coordinate data. In this way, correction for occlusions detected by both profilometers may be improved.

In one example, the method comprises: acquiring, by the first profilometer, a first segment of a set of segments of a second measured cross-sectional profile of the set of measured cross-sectional profiles of the occluded, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a second part of the surface of the article and a second part of the surface of the first occlusion; transmitting, by the first profilometer, the first set of coordinate data of the first segment to the computer; receiving, by the computer, the first set of coordinate data of the first segment; correcting, by the computer, the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data; and determining, by the computer, the second part of the surface of the article based, at least in part, on the corrected first segment.

In this way, the second part of the surface of the article is determined based, at least in part, on the corrected first segment, for example additionally and/or alternatively to based, at least in part, on the corrected second segment. In this way, parts of the occluded surface may be determined using differently -oriented profilometers, thereby attenuating the effect of the first occlusion and hence more reliably determining the second part of the surface of the article, increasing resolution and/or reducing errors of the cross-sectional profile.

In one example, correcting the first segment for the first occlusion comprises identifying coordinate data of the first part of the surface of the first occlusion by comparing first and second coordinate data of the first set of coordinate data and by comparing first and second coordinate data of the second set of coordinate data.

In this way, first part of the surface of the first occlusion, for example an extent thereof, may be confirmed. In this way, an incidence of false positives may be reduced, thereby improving the determining of the surface of the article.

Moving the article The method comprises moving, by the conveyor, the article in the first dimension through the first measurement area, as described with respect to the first aspect, mutatis mutandis.

Occluding the surface The method comprises occluding, at least in part, the first part of the surface of the moving article by the first occlusion in the first measurement area. That is, the first occlusion obstructs measurement, by the first non-contact profilometer of at least pad of the surface of the moving article that would otherwise be measured in the absence of the first occlusion. In other words, the first occlusion would give rise to an artefact, unless correction is made, particularly a convexity or protrusion, as described with respect to the first aspect. Conventionally, parts of the surface of the article may be occluded for example permanently such as by supports for the set of non-contact profilometers and/or other infrastructure. However, conventionally, the set of non-contact profilometers may be arranged, for example spatially, to minimise or eliminate such occlusion. In contrast, it should be understood that the first occlusion comprises and/or is a transient or temporary occlusion. It should be understood that the first occlusion is not a part of the article nor of the apparatus, for example, according to the sixth aspect. In one example, occluding, at least in part, the first part of the surface of the moving article by the first occlusion in the first measurement area comprises transiently occluding at least in part, the first part of the surface of the moving article by the first occlusion in the first measurement area.

In one example, the first occlusion comprises and/or is debris (also known as a foreign body). Conventionally, use of non-contact profilometers is restricted to relatively clean, still environments. However, potential industrial applications may be in relatively dirty, turbulent environments. In such environments, debris such as dust may be blown and/or fall through the first measurement area. Additionally and/or alternatively, debris present on the surface may bounce thereon due to vibration of the moving article. Such bouncing debris may give rise to an artefact, unless correction is made, for example an apparent roughness of the surface. In some industrial environments, the first occlusion could be droplets of liquid falling on the surface, for example lubricating oil or water. In one example, the first occlusion comprises and/or is debris, for example a particle, an agglomerate, a flake such as scale or rust, a chip or swarf. In one example, the first occlusion has a dimension, for example a maximum dimension, in a range from 0.01 mm to 100 mm, preferably in a range from 0.05 mm to 10 mm, more preferably in a range from 0.075 mm to 5 mm, most preferably in a range from 0.1 mm to 2.5 mm. That is, the dimension of the first occlusion may be greater than a resolution of the first non-contact profilometers and/or of the order or larger than a tolerance for the article.

In one example, the first occlusion and the article are mutually spaced apart. That is, there is a gap between the first occlusion and the article, for example, the surface thereof. For example, blown, falling or bouncing debris is generally spaced apart from the surface, unless in contact therewith such as collected thereon or between bounces.

In one example, the first occlusion is translating and/or rotating in the first, second and/or third dimensions, for example relative to the moving article and/or the first non-contact profilometer. That is, a position and/or orientation of the first occlusion is changing, for example intermittently or continuously, for example before and/or during acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles.

In one example, a difference in speed in the first, second and/or third dimensions between the first occlusion and the article is in a range from 0.01 ms-1 to 100 ms-1, in a range from 0.1 ms-1 to 10 ms-1, preferably in a range from 0.5 ms-1 to 5 ms-1, more preferably in a range from 1 ms- 1 to 2.5 ms-1. That is, the difference in speed may be comparable with a speed of moving of the article in the first dimension.

In one example, the method comprises occluding, at least in part, the first part of the surface of the moving article by a set of occlusions, including the first occlusion, in the first measurement area. In one example, the set of occlusions includes 0 occlusions, wherein 0 is a natural number greater than or equal to 1, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. That is, the first part of the surface may be occluded, for example simultaneously, by 1 or more, for example a plurality of, occlusions. Each occlusion may be as described with respect to the first occlusion.

In contrast to the first aspect, the method comprises occluding rather than displacing the article. However, it should be understood that the moving article may be both displaced and occluded and hence the methods according to the first aspect and the fifth aspect may be combined accordingly. In one example, method comprises displacing the moving article by a first displacement of a set of displacements in the second and/or the third dimension.

Acquiring the first segment of the first measured cross-sectional profile The method comprises acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the occluded, moving article in the first measurement area, wherein the first segment comprises the first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and the first part of the surface of the first occlusion, generally as described with respect to the first aspect, mutatis mutandis.

In contrast to the first aspect, the moving article is occluded rather than displaced. However, it should be understood that the moving article may be both displaced and occluded and hence the methods according to the first aspect and the fifth aspect may be combined accordingly. Hence, in one example, acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the occluded, moving article in the first measurement area comprises acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the occluded, displaced, moving article in the first measurement area.

Transmitting and receiving The method comprises transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile, as described with respect to the first aspect, mutatis mutandis.

The method comprises receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile, as described with respect to the first aspect, mutatis mutandis.

Correcting for the occlusion The method comprises correcting, by the computer, the first segment for the first occlusion, thereby providing the corrected first segment comprising a first set of corrected coordinate data, generally as described with respect to the first aspect, mutatis mutandis. In this way, the first set of coordinate data is corrected for the first occlusion, such that an artefact due to the first occlusion on the first part of the surface is substantially reduced and/or eliminated. In other words, the first occlusion is accounted or compensated for, thereby improving measurement of the surface of the article and hence a more accurate and/or precise representation of the surface.

In one example, correcting the first segment for the first occlusion comprises identifying coordinate data of the first part of the surface of the first occlusion by comparing first and second coordinate data of the first set of coordinate data. In this way, outliers in the first set of coordinate data, for example due to the first occlusion, may be identified and subsequently resolved.

In one example, the first and the second coordinate data are mutually adjacent. That is, the first and the second coordinate data are neighbours, for example immediate neighbours, in the first set of coordinate data.

In one example, a distance between the first and the second coordinate data is greater than a predetermined threshold distance. In this way, outliers may be identified and/or discriminated. In one example, identifying coordinate data of the first part of the surface of the first occlusion by comparing first and second coordinate data of the first set of coordinate data comprises calculating a distance between the first and the second coordinate data and comparing the calculated distance with a predetermined threshold distance.

In one example, correcting the first segment for the first occlusion comprises replacing the coordinate data of the first part of the surface of the first occlusion in the first set of corrected coordinate data. That is, coordinate data corresponding with the first occlusion are replaced, thereby attenuating and/or removing an artefact due thereto.

In one example, replacing the coordinate data of the first part of the surface of the first occlusion comprises removing the coordinate data of the first part of the surface of the first occlusion from the first set of corrected coordinate data. That is, the coordinate data corresponding with the first occlusion are removed.

In one example, replacing the coordinate data of the first part of the surface of the first occlusion comprises substituting the coordinate data of the first part of the surface of the first occlusion in the first set of corrected coordinate data, for example with obtained and/or calculated, for example by smoothing, coordinate data such as obtained from adjacent coordinate data of the first set of corrected coordinate data from the first measured cross-sectional profile and/or from the set of set of measured cross-sectional profiles, for example from an adjacent measured cross-sectional profile such as a zeroth measured cross-sectional profile and/or a second measured cross-sectional profile. Algorithms for smoothing are known.

That is, the coordinate data corresponding with the first occlusion are substituted, for example with smoothed, such as interpolated, coordinate data.

In one example, the method comprises occluding, at least in part, the first part of the surface of the moving article by a set of occlusions, including the first occlusion, in the first measurement area and correcting, by the computer, the first segment for the first occlusion comprises correcting, by the computer, the first segment for the set of occlusions, including the first occlusion, for example as described with respect to the first occlusion.

In contrast to the first aspect, the moving article is occluded rather than displaced. However, it should be understood that the moving article may be both displaced and occluded and hence the methods according to the first aspect and the fifth aspect may be combined accordingly.

In one example, the method comprises correcting, by the computer, the first segment for a first displacement by a first correction, thereby providing the corrected first segment comprising the first set of corrected coordinate data of the first measured cross-sectional profile.

Determining the first part of the surface of the article The method comprises determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected first segment. In this way, by determining the first part of the surface of the article based, at least in part, on the corrected first segment, a more accurate and/or precise representation of the surface is provided. In this way, the advantages of non-contact profilometry may be realised in applications where occlusions are present and/or cannot be controlled to below a limit of resolution of the non-contact profilometry and/or below a limit of interest of the surface of the article (for example, a permitted tolerance). In this way, the surface of the article may be determined in the absence of occlusion, thereby allowing inspection of surface features of the article at a relatively higher resolution than otherwise possible without correction.

It should be understood that successive parts of the surface may be determined similarly. In one example, the method comprises determining a set of parts, including the first part, of the surface of the article, for each part of the set of parts, as described with respect to the first part.

In one example, the method comprises aggregating the set of measured cross-sectional profiles and/or the determined surfaces thereof, as described previously.

Sixth aspect The sixth aspect provides an apparatus for determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the apparatus comprising: a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; a conveyor configured to move the article in the first dimension through the first measurement area; and a computer including a processor and a memory; wherein the first profilometer is configured to: acquire a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a first part of a surface of a first occlusion; and transmit the first set of coordinate data of the first segment to the computer; and wherein the computer is configured to: receive the first set of coordinate data of the first segment; correct the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data; and determine the first part of the surface of the article based, at least in part, on the corrected first segment.

The first part of the surface, the article, the axial length, the first dimension, the cross-sectional profile, the mutually transverse second and third dimensions, the set of non-contact profilometers, the first profilometer, the first optical profilometer, the first measurement area, the first segment of the set of segments of the first measured cross-sectional profile, the set of measured cross-sectional profiles, the moving article, the conveyor, the occlusion, the first part of the surface of the occlusion, the first segment, the first set of coordinate data, the correcting, the corrected first segment comprising the first set of corrected coordinate data of the first measured cross-sectional profile and/or the first part of the surface of the article may be as described with respect to the fifth aspect, mutatis mutandis.

The apparatus may be configured to implement the method, for example any step thereof, according to the first aspect and/or the fifth aspect.

Seventh aspect The seventh aspect provides a computer for determining, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the computer comprising a processor and a memory, wherein the computer is configured to: receive a first set of coordinate data of a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the article, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a first part of a surface of a first occlusion; correct the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data; and determine the first part of the surface of the article based, at least in part, on the corrected first segment.

The first part of the surface, the article, the axial length, the first dimension, the cross-sectional profile, the mutually transverse second and third dimensions, the set of non-contact profilometers, the first profilometer, the first optical profilometer, the first measurement area, the first segment of the set of segments of the first measured cross-sectional profile, the set of measured cross-sectional profiles, the moving article, the conveyor, the occlusion, the first part of the surface of the occlusion, the first segment, the first set of coordinate data, the correcting, the corrected first segment comprising the first set of corrected coordinate data of the first measured cross-sectional profile and/or the first part of the surface of the article may be as described with respect to the fifth aspect, mutafis mutandis.

The computer may be configured to implement the method, for example any step thereof, according to the first aspect and/or the fifth aspect.

Eighth aspect The eighth aspect provides a tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by computer device including at least a processor and a memory, cause the computer device to perform a method of determining, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method according to the first aspect and/or the fifth aspect.

Ninth aspect The ninth aspect provides a method of inspecting a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method implemented, at least in part, by a computer including a processor and a memory, the method comprising: providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; moving, by a conveyor, the article in the first dimension through the first measurement area; acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; determining, by the computer, the first part of the surface of the article based, at least in part, on the first segment; generating, by the computer, a generated first part of the surface of the article using the determined first part of the surface; comparing, by the computer, the determined first part of the surface and the generated first part of the surface; and inspecting, by the computer, the article based on a first result of the comparing.

In this way, the article may be inspected, for example to identify deviations from dimensional tolerances and/or to identify defects. Particularly, since the inspection is performed by the computer using the coordinate data received from the set of profilometers, the inspection is automated. Further, since the coordinate data are acquired from the moving article, a rate of inspecting of the article may be increased. In addition, a greater proportion of the actual length of the article may be inspected, for example the whole axial length. In this way, compliance with cross-sectional dimensional tolerances may be verified for the whole axial length, for example. Furthermore, since the set of profilometers may be arranged to measure a greater proportion of the cross-sectional profile, for example the whole cross-sectional profile, assessment of the presence of defects is not limited to only accessible services, such that even though the services may be inspected. Additionally, since the inspection of the moving article is automated, the inspection may be integrated as part of processing, for example manufacturing, of the article. In this way, non-compliance or defects may be identified sooner, for example online or in real-time, enabling remedial action to be undertaken to the article and or to the processing and/or automated quarantining of rejected articles. In this way, inspection of articles, such as hot rolled steel profiles, is improved.

The first part of the surface, the article, the axial length, the first dimension, the cross-sectional profile, the mutually transverse second and third dimensions, the set of non-contact profilometers, the first profilometer, the first optical profilometer, the first measurement area, the first segment of the set of segments of the first measured cross-sectional profile, the set of measured cross-sectional profiles, the moving article, the conveyor, the first segment and/or the first set of coordinate data may be as described with respect to the first aspect and/or the fifth aspect, mutatis mutandis.

The method according to the ninth aspect may include the method, for example any step thereof, according to the first aspect and/or the fifth aspect. Particularly, it should be understood that the method according to the ninth aspect may include correcting, by the computer, the first segment for a first displacement by a first correction, as described with respect to the first aspect. Similarly, it should be understood that the method according to the ninth aspect may include correcting, by the computer, the first segment for a first occlusion, as described with respect to the fifth aspect.

The steps of providing the set of non-contact profilometers, moving, by the conveyor, the article, acquiring, by the first profilometer, the first segment, transmitting, by the first profilometer, the first set of coordinate data and/or receiving, by the computer, the first set of coordinate data maybe as described with respect to the first aspect and/or the fifth aspect, mutatis mutandis, and will not be repeated for brevity.

Article The method is of inspecting the first part of the surface of the article having the axial length extending in the first dimension and the cross-sectional profile in mutually transverse second and third dimensions, as described with respect to the first aspect, mutatis mutandis.

It should be understood that the inspecting of the first part of the surface of the article is based on comparing the determined first part of the surface and the generated first part of the surface, using the first measured cross-sectional profile or a segment thereof. In this way, the measured cross-sectional profile of the article is inspected, for example each measured cross-sectional profile of the article is inspected. In this way, non-compliance or a defect in a single measured cross-sectional profile (i.e. in the second and third dimensions) may be identified, as well as non-compliance or a defect extending, for example additionally, in the first dimension.

Non-contact pro filometry The method comprises providing the set of non-contact profilometers including the first profilometer, for example the first optical profilometer, defining the first measurement area, as described with respect to the first aspect, mutatis mutandis.

In one example, providing the set of non-contact profilometers comprises providing the set of non-contact profilometers including a second profilometer, for example a second optical profilometer, defining a second measurement area; and the method comprises: acquiring, by the second profilometer, a second segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the second measurement area, wherein the second segment comprises a second set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; transmitting, by the second profilometer, the second set of coordinate data of the second segment to the computer; receiving, by the computer, the second set of coordinate data of the second segment; and determining, by the computer, the first part of the surface of the article based, at least in part, on the second segment.

Acquiring the first segment of the first measured cross-sectional profile The method comprises acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises the first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article, generally as described with respect to the first aspect and/or the fifth aspect, mutafis mutandis.

It should be understood that the moving article may be displaced and/or occluded and hence the methods according to the first aspect and/or the fifth aspect may be combined with the method according to the ninth aspect accordingly. Hence, in one example, acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the first measurement area comprises acquiring, by the first profilometer, the first segment of the set of segments of the first measured cross-sectional profile of the set of measured cross-sectional profiles of the occluded and/or displaced, moving article in the first measurement area.

Transmitting and receiving The method comprises transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile, as described with respect to the first aspect and/or the fifth aspect, mutafis mutandis.

The method comprises receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile, as described with respect to the first aspect and/or the fifth aspect, mutafis mutandis.

Determining the first part of the surface of the article The method comprises determining, by the computer, the first part of the surface of the article based, at least in part, on the first segment, as described with respect to the first aspect and/or the fifth aspect, mutatis mutandis.

As described with respect to the first aspect, the determined first part of the surface is thus a part of the measured surface of the article, after any correction thereto. Hence, the determined first part of the surface may be represented by a series of points and/or by a line in one or two dimensions, corresponding with at least a part of the cross-sectional profile of the article. By similarly determining other parts of the surface using the coordinate data from the set of segments and aggregating or combining these determined parts of the surface, the whole of the cross-sectional profile of the article may be represented by a series of points and/or by a line in two dimensions, which may be termed a slice, for example.

Generating the first part of the surface of the article The method comprises generating, by the computer, the generated first part of the surface of the article using the determined first part of the surface.

The determined first part of the surface is thus a part of the measured surface of the article, after any correction thereto, as described above. In contrast, the generated first part of the surface is generated using this measured surface, for example the coordinate data and/or the corrected coordinate data. For example, the generated first part of the surface may comprise a calculated surface, calculated from the coordinate data and/or the corrected coordinate data.

Particularly, the inventors have found that inspecting based only on design dimensions, for example such as hot rolled steel profiles, such as shown on CAD drawings and/or in standards, is not sufficiently reliable because of interplay between different dimensions and tolerances. That is, reliable inspection requires analysis of the local surface in the context of the particular cross-sectional profile. In this way, non-compliance and/or defects may be better identified and/or characterised. Particularly, the article may be inspected without prior knowledge of design dimensions (i.e. shape or geometry). Rather, by generating the surface of the article and comparing the generated surface with the determined (i.e. measured) surface, the article may be inspected based on differences therebetween. In this way, a range of articles, for example hundreds of articles each having different cross-sectional profiles, may be inspected, without design dimensions thereof.

Since the cross-sectional profile is of an article, the cross-sectional profile is closed i.e. a continuous line may be scribed around the whole cross-sectional profile, for example.

In one example, generating, by the computer, the generated first part of the surface of the article using the determined first part of the surface comprises modelling the determined first part of the surface. That is, the coordinate data and/or the corrected coordinate data are modelled mathematically, for example optionally using design dimensions of the article.

In one example, modelling the determined first part of the surface comprises ab inifio modelling of the determined first part of the surface. That is, the modelling uses only the coordinate data and/or the corrected coordinate data, for example without design dimensions of the article.

In one example, generating, by the computer, the generated first part of the surface of the article using the determined first part of the surface comprises fitting a first curve of a set of curves, in the second and/or the third dimensions, to the first set of coordinate data of the first segment of the first measured cross-sectional profile. It should be understood that the first set of coordinate data may comprise corrected coordinate data. That is, the first set of coordinate data are described mathematically using an equation.

In one example, fitting the first curve of the set of curves, in the second and/or the third dimensions, to the first set of coordinate data of the first segment of the first measured cross-sectional profile comprises smoothing the first set of coordinate data of the first segment of the first measured cross-sectional profile. In this way, local deviations between adjacent data points may be smoothed, thereby providing a better geometric representation.

In one example, smoothing the first set of coordinate data of the first segment of the first measured cross-sectional profile comprises moving average smoothing, for example simple, central, cumulative, weighted or exponential moving average smoothing. A sample window size may be determined on the measurement resolution and/or on a curvature of the cross-sectional profile of the article, for example.

In one example, the first curve comprises an Nth degree polynomial, wherein N is a natural number greater than or equal to 1, in a range from 2 to 10, preferably in a range from 2 to 8, more preferably in a range from 3 to 7. In this way, relatively complex cross-sectional profiles may be modelled, including cross-sectional profiles having 2, 3, 4, 5, 6, 7, 8, 9, 10 or more internal and/or external corners. Particularly, corners tend to have tight curvature which may not be sufficiently well represented when N is relatively small, for example less than 3, resulting in underfitting. If N is too large, however, overfitfing may result such that the first curve seeks to pass through most or all of the coordinate data.

In one example, the method comprises training, by the computer, a machine learning, ML, algorithm using a training dataset, such as obtained from articles as described herein.

In one example, generating, by the computer, the generated first part of the surface of the article using the determined first part of the surface comprises inferring the generated first part of the surface of the article using the determined first part of the surface and the trained ML algorithm.

Comparing the determined and the generated first part of the surface The method comprises comparing, by the computer, the determined first part of the surface and the generated first part of the surface. That is, the determined or measured surface is compared with the generated surface, so as to establish differences therebetween.

In one example, comparing, by the computer, the determined first part of the surface and the generated first part of the surface comprises calculating a first difference of a set of differences therebetween. For example, each datum of the coordinate data maybe compared with a corresponding datum of the generated surface.

Inspecting the article The method comprises inspecting, by the computer, the article based on the first result of the comparing. In this way, the article may be inspected, for example to identify deviations from dimensional tolerances and/or to identify defects, as described above.

In one example, inspecting the article based on the first result of the comparing comprises identifying a first defect based, at least in part, on a first difference of a set of differences between the determined first part of the surface and the generated first part of the surface, for example calculated as described above. That is, the first result of the comparing is the first difference.

In one example, the method comprises: acquiring, by the first profilometer, a first segment of a set of segments of a second measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a second part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the second measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the second measured cross-sectional profile; determining, by the computer, the second part of the surface of the article based, at least in part, on the first segment; generating, by the computer, a generated second part of the surface of the article using the determined second part of the surface; comparing, by the computer, the determined second pad of the surface and the generated second part of the surface; and inspecting, by the computer, the article based on the first result and/or a second result of the comparing.

In this way, non-compliance or a defect extending in the first dimension, as well as the second and/or third dimensions, may be identified from the first and second measured cross-sectional profiles.

In one example, the method comprises repeating the acquiring, the transmitting, the receiving, the determining, the comparing and/or the inspecting for each measured cross-sectional profile of the set of measured cross-sectional profiles, for example for the whole axial length of the article. In this way, the whole surface of the article may be inspected.

In one example, the method comprises aggregating the set of measured cross-sectional profiles, the determined surfaces thereof, the generated surfaces thereof and/or the results of comparing, as described previously. In this way, an inspection report for the article may be provided.

Occluding In one example, the method comprises: occluding, at least in part, the first part of the surface of the moving article by a first occlusion in the first measurement area; and correcting, by the computer, the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data.

In this way, the first segment may be corrected for the first occlusion, for example as described with respect to the fifth aspect.

Displacing In one example, the method comprises: displacing the moving article by a first displacement of a set of displacements in the second and/or the third dimension; and correcting, by the computer, the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile.

In this way, the first segment may be corrected for the first displacement, for example as described with respect to the first aspect.

Action In one example, the method comprises executing, by the computer, an action, for example a remedial action, in response to the comparing. For example, in response to identifying noncompliance or a defect, the computer may transmit a signal to divert conveying of the article and/or to control processing of a subsequent article.

Tenth aspect The tenth aspect provides an apparatus for inspecting a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the apparatus comprising: a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; a conveyor configured to move the article in the first dimension through the first measurement area; and a computer including a processor and a memory; wherein the first profilometer is configured to: acquire a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; and transmit the first set of coordinate data of the first segment of the first measured cross-sectional profile to the computer; and wherein the computer is configured to: receive the first set of coordinate data of the first segment of the first measured cross-sectional profile; determine the first part of the surface of the article based, at least in part, on the first segment; generate a generated first part of the surface of the article using the determined first part of the surface; compare the determined first part of the surface and the generated first part of the surface. and inspect the article based on a first result of the comparing.

The first part of the surface, the article, the axial length, the first dimension, the cross-sectional profile, the mutually transverse second and third dimensions, the set of non-contact profilometers, the first profilometer, the first optical profilometer, the first measurement area, the first segment of the set of segments of the first measured cross-sectional profile, the set of measured cross-sectional profiles, the moving article, the conveyor, the first segment, the first set of coordinate data, the first part of the surface, the generated first part of the surface, the determined first part of the surface, the comparing, the inspecting and/or first the result of the comparing may be as described with respect to the ninth aspect, mutatis mutandis.

The apparatus may be configured to implement the method, for example any step thereof, according to the first aspect, the fifth aspect and/or the ninth aspect.

Eleventh aspect The eleventh aspect provides a computer for inspecting, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the computer comprising a processor and a memory, wherein the computer is configured to: receive a first set of coordinate data of a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; receive the first set of coordinate data of the first segment of the first measured cross-sectional profile; determine the first part of the surface of the article based, at least in part, on the first segment; generate a generated first part of the surface of the article using the determined first part of the surface; compare the determined first part of the surface and the generated first part of the surface and inspect the article based on a first result of the comparing.

The first pad of the surface, the article, the axial length, the first dimension, the cross-sectional profile, the mutually transverse second and third dimensions, the set of non-contact profilometers, the first profilometer, the first optical profilometer, the first measurement area, the first segment of the set of segments of the first measured cross-sectional profile, the set of measured cross-sectional profiles, the moving article, the conveyor, the first segment, the first set of coordinate data, the first pad of the surface, the generated first part of the surface, the determined first part of the surface, the comparing, the inspecting and/or first the result of the comparing may be as described with respect to the ninth aspect, mutafis mutandis.

The computer may be configured to implement the method, for example any step thereof, according to the first aspect, the fifth aspect and/or the ninth aspect.

Twelfth aspect The twelfth aspect provides a tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by computer device including at least a processor and a memory, cause the computer device to perform a method of inspecting, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method according to the first aspect, the fifth aspect and/or the ninth aspect.

Definitions Throughout this specification, the term "comprising" or "comprises" means including the component(s) specified but not to the exclusion of the presence of other components. The term "consisting essentially of" or "consists essentially or means including the components specified but excluding other components except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for a purpose other than achieving the technical effect of the invention, such as colourants, and the like.

The term "consisting or or "consists or means including the components specified but excluding other components.

Whenever appropriate, depending upon the context, the use of the term "comprises" or "comprising" may also be taken to include the meaning "consists essentially or or "consisting essentially of', and also may also be taken to include the meaning "consists or or "consisting of".

The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention, as set out herein are also applicable to all other aspects or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or exemplary embodiment of the invention as interchangeable and combinable between different aspects and exemplary embodiments.

Brief description of the drawings

For a better understanding of the invention, and to show how exemplary embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which: Figure 1A schematically depicts a method according to an exemplary embodiment; Figure 1B schematically depicts a method according to an exemplary embodiment; Figure 10 schematically depicts a method according to an exemplary embodiment; and Figure 1D schematically depicts a method according to an exemplary embodiment; Figures 2A and 2B schematically depict an apparatus according to an exemplary embodiment; Figures 3A to 3K schematically depict a method according to an exemplary embodiment using the apparatus of Figure 2; Figures 4A, 4B, 4C and 4D are photographs of straightening of a hot rolled steel profile, before inspecting by a method according to an exemplary embodiment; Figures 5A, 5B, 50 and 5D are photographs of inspecting of a straightened hot rolled steel profile, by a method according to an exemplary embodiment; Figures 6A, 6B, 60 and 6D are photographs of inspecting of a straightened hot rolled steel profile, by a method according to an exemplary embodiment; Figure 7A schematically depicts a method according to an exemplary embodiment; Figure 78 is a perspective view of raw data, before correcting, for a hot rolled steel profile; Figure 7C is a perspective view of the corrected data, corrected using the method of Figure 7A; and Figure 7D is a cross-sectional profile from the corrected data of Figure 70; Figure 8A is a perspective view of a hot rolled steel profile, particularly a single grouser; Figure 8B is a cross-section view of the hot rolled steel profile showing relative incidence of surface defects; Figure 8C is a photograph of a typical surface defect in the leading toe of the hot rolled steel profile; and Figure 8D is a photograph of a typical surface defect in the leading edge of spike of the hot rolled steel profile; Figure 9A is a perspective view of corrected data, corrected using the method of Figure 6, for a hot rolled steel profile; Figure 9B is a photograph of the hot rolled steel profile of Figure 9A; Figure 9C is a perspective view of corrected data, corrected using the method of Figure 6, for a hot rolled steel profile; and Figure 9D is a photograph of the hot rolled steel profile of Figure 9C; Figure 10 schematically depicts a surface quality index of a hot rolled steel profile; Figures 11A, 11B and 11C are photographs of hot rolled steel profiles having surface defects in surfaces thereon; Figures 12 is a photograph of a hot rolled steel profile according to an exemplary embodiment; Figures 13A is a photograph of a hot rolled steel profile having surface defects in a surface thereof and Figure 13B is a photograph of a hot rolled steel profile according to an exemplary embodiment; Figure 14 schematically depicts a cross-section of a bulb flat according to an exemplary 25 embodiment; Figure 15 schematically depicts a cross-section of a crane rail according to an exemplary embodiment; Figures 16A to 16C schematically depict cross-sections of track shoe profiles according to exemplary embodiments; Figures 17A to 17D schematically depict cross-sections of cutting edge profiles according to exemplary embodiments; and Figure 18 schematically depicts a cross-sections of a top hat profile according to exemplary embodiment.

Detailed Description of the Drawings

Figure 1A schematically depicts a method according to an exemplary embodiment. The method is of determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions. The method is implemented, at least in part, by a computer including a processor and a memory.

At 8101, the method comprises providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area.

At 8102, the method comprises moving, by a conveyor, the article in the first dimension through the first measurement area.

At 8103, the method comprises acquiring, by the first profilometer, a first segment of a set of segments of a zeroth measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a zeroth part of the surface of the article.

At 8104, the method comprises displacing the moving article by a first displacement of a set of displacements in the second and/or the third dimension.

At 8105, the method comprises acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article.

At 8106, the method comprises transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile.

At 8107, the method comprises receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile.

At S108, the method comprises correcting, by the computer, the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile.

At S109, the method comprises determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected first segment.

Figure 1B schematically depicts a method according to an exemplary embodiment. The method is of determining a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions. The method is implemented, at least in part, by a computer including a processor and a memory.

At S201, the method comprises providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area.

At S202, the method comprises moving, by a conveyor, the article in the first dimension through the first measurement area.

At S203, the method comprises occluding, at least in part, the first part of the surface of the moving article by a first occlusion in the first measurement area.

At S204, the method comprises acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the occluded, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a first part of a surface of the first occlusion.

At S205, the method comprises transmitting, by the first profilometer, the first set of coordinate data of the first segment to the computer.

At S206, the method comprises receiving, by the computer, the first set of coordinate data of the first segment.

At S207, the method comprises correcting, by the computer, the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data.

At S208, the method comprises determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected first segment.

Figure 10 schematically depicts a method according to an exemplary embodiment. The method is of inspecting a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions. The method is implemented, at least in part, by a computer including a processor and a memory.

At S301, the method comprises providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area.

At S302, the method comprises moving, by a conveyor, the article in the first dimension through the first measurement area.

At 8303, the method comprises acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article.

At 8304, the method comprises transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile.

At 8305, the method comprises receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile.

At S306, the method comprises determining, by the computer, the first part of the surface of the article based, at least in part, on the first segment.

At S307, the method comprises generating, by the computer, a generated first part of the surface of the article using the determined first part of the surface.

At 8308, the method comprises comparing, by the computer, the determined first part of the surface and the generated first part of the surface.

At 8309, the method comprises inspecting, by the computer, the article based on a first result of the comparing.

Figure 1D schematically depicts a method according to an exemplary embodiment.

Particularly, the method combines the methods of Figures 1A, 1B and 1C; like reference signs are used for consistency. The method is of inspecting a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions. The method is implemented, at least in part, by a computer including a processor and a memory.

At 3301, the method comprises providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area.

At 5302, the method comprises moving, by a conveyor, the article in the first dimension through the first measurement area.

At 3401, the method comprises acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, occluded moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article and a first part of a surface of the first occlusion. Step S401 thus combines steps S105 and S204.

At 3304, the method comprises transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile.

At S305, the method comprises receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile.

At 5402, the method comprises correcting, by the computer, the first segment for the first displacement by a first correction and correcting, by the computer, the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data. Step 8402 thus combines steps 8108 and 8207.

At 403, the method comprises determining, by the computer, the first part of the surface of the article based, at least in part, on the corrected first segment. Step S403 thus combines steps 8109 and 8208.

At S308, the method comprises comparing, by the computer, the determined first part of the surface and the generated first part of the surface.

At S309, the method comprises inspecting, by the computer, the article based on a first result of the comparing.

Figures 2A and 2B schematically depicts an apparatus 10 according to an exemplary embodiment; and Figures 3A to 3K schematically depict a method according to an exemplary embodiment using the apparatus 10 of Figures 2A and 2B.

The apparatus for 10 is for determining and/or inspecting a first part of a surface S of an article A having an axial length L extending in a first dimension Y and a cross-sectional profile in mutually transverse second X and third Z dimensions, as described with respect to the second aspect, the sixth aspect and/or the tenth aspect.

In this example, the apparatus comprises: a set of 3 optical non-contact profilometers 100 using triangulation, including a first profilometer 100A, a second profilometer 100B and a third profilometer 1000, defining respectively a first measurement area 110A, a second measurement area 110B and a third measurement area 110C; a roller conveyor 200 configured to move the article A in the first dimension Y through the first measurement area 110A, the second measurement area 110B and the third measurement area 1100; and a computer (not shown) including a processor and a memory.

The first profilometer 100A is configured to: acquire a first segment of a set of segments of a zeroth measured cross-sectional profile PO of a set of measured cross-sectional profiles of the moving article A in the first measurement area 110A, wherein the first segment comprises a first set of coordinate data, in the second X and the third Z dimensions, of a zeroth part of the surface S of the article A; acquire a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced (and optionally occluded), moving article in the first measurement area 110A, wherein the first segment comprises a first set of coordinate data, in the second X and the third Z dimensions, of the first part of the surface of the article A, wherein the moving article A is displaced by a first displacement of a set of displacements in the second X and/or the third Z dimension; and transmit the first set of coordinate data of the first segment of the first measured cross-sectional profile to the computer.

In this example, the set of profilometers 100 is arranged such that the respective measurement areas are coplanar in the second and third dimensions and equispaced on the locus of a circle (i.e. by 120°), the radius of which is defined so as to maximise a cross-sectional profile that may be measured for the respective measurement areas. In this example, the second and third profilometers 100B, 1000 are configured similarly to the first profilometer 100A, mutatis mutandis.

In this example, the computer is configured as described with respect to the second aspect, the sixth aspect and/or the tenth aspect.

The apparatus 10 may be configured and/or include any of the features as described with respect to the second aspect, the sixth aspect and/or the tenth aspect and/or to implement the methods as described with respect to the first aspect, the fifth aspect and/or the ninth aspect.

Figure 3A shows a cross-sectional profile of a single grouser (i.e. an article A having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions). The article A is moved, by the conveyor, in the first dimension through the respective measurement areas of the three optical profilometers. In this example, each measured cross-sectional profile consists of three segments, corresponding to the three optical profilometers.

Figure 3B schematically depicts the three segments Si, S2, 83 of the measured cross-sectional profile, schematically showing a simplified representation of the respective sets of coordinate data, having relatively fewer coordinate data, which may be termed a slice. Individual coordinate data (i.e. data points) are shown as dots. In this example, the three segments 51, S2, S3 are time-aligned, having the same or adjacent time-stamps, thereby identifying that the three segments S1, 82, 83 are of the same measured cross-sectional profile. However, coordinate systems for the three segments Si, S2, S3 are, at this stage, independent since the three segments S1, 52, S3 are obtained from the three optical profilometers 100A, 100B, 1000 that are physically situated and oriented independently. Hence, the three segments Si, 82, 83, at this stage, are illustrated schematically according to a default coordinate system, in which each optical profilometer is vertically above the respective segment. In this example, debris such as scale present occlusions, which are measured by the three optical profilometers 100A, 100B, 100C and shown as data points (or speckles), separated from remaining data points of the three segments Sl, 52, 83.

Figure 3C schematically depicts the three segments Si, 52, S3 of the measured cross-sectional profile after correcting for geometry of the three optical profilometers 100A, 100B, 100C. By correcting for geometry, the three segments 51, 82, 83 of the measured cross-sectional profile are translated, rotated and optionally scaled according to predetermined geometry corrections, that are similarly applied to each measured cross-sectional profile.

Particularly, the three segments 81, 82, 83 are mutually translated, rotated and optionally scaled according to the predetermined geometry corrections, since the segments are obtained from the three optical profilometers that are physically situated and oriented independently. In this way, the three segments S1, S2, S3 of each measured cross-sectional profile are positioned and optionally scaled consistently in coordinate space, though the measured cross-sectional profiles may each be relatively displaced, for example due to vibrations, bounce and/or dropping the article A on the conveyor 200.

Figure 3D schematically depicts the three segments Si, S2, 53 of the measured cross-sectional profile after correcting for the occlusions (or despeckling). In this example, the data points corresponding with the occlusions 0 (as shown generally in Figure 3C) are removed.

Figures 3E to 3H schematically depict correction for displacement (or debouncing) of the article during the measuring.

Figure 3E shows selection of a particular segment Sl, corresponding to a nominated optical profilometer (also known as a master), as a reference segment. In this example, the same particular optical profilometer 100A is nominated for each measured cross-sectional profile, such that the same corresponding particular segment is selected for each measured cross-sectional profile. A relatively linear portion LP of the particular segment 81 is identified.

Figure 3F shows the particular segment Si after anticlockwise rotation thereof such that the relatively linear portion LP of the particular segment 51 is oriented horizontally, aligning with a first reference axis Al (i.e. corresponds with a first datum). The first datum may be predetermined or may be obtained from the zeroth measured cross-sectional profile, for example. In this example, the same corresponding particular segment Si is selected for each measured cross-sectional profile and similarly rotated to correspond with the same first datum. However, since the measured cross-sectional profiles may each be relatively displaced, the rotation may be different. In this way, by rotating the same particular segments of each measured cross-sectional profile to correspond with the same first datum, the coordinate data are corrected for rotational components of respective displacements.

Figure 3G shows the particular segment SI after translation thereof such that an end of the particular segment is coincident with the origin of the first reference axis Al and a second reference axis A2 orthogonal thereto (i.e. corresponds with a second datum). The second datum may be predetermined or may be obtained from the zeroth measured cross-sectional profile, for example. In this example, the same corresponding particular segment Si is selected for each measured cross-sectional profile and similarly translated to correspond with the same second datum. However, since the measured cross-sectional profiles may each be relatively displaced, the translation may be different. In this way, by translating the same particular segment Si of each measured cross-sectional profile to correspond with the same second datum, the coordinate data are corrected for translational components of respective displacements.

Figure 3H shows the measured cross-sectional profile after rotation and translation of the remaining segments S2, S3, by the same rotation and the same translation as for the particular segment. By similarly rotating and translating each measured cross-sectional profile to correspond with the same first datum and second datum, each measured cross-sectional profile is corrected for the rotational and the translational components of the respective displacements.

Figure 31 shows the generated surface GS of the article A, shown as a dotted line with an enlarged view inset. The generated surface GS was generated by moving average smoothing the coordinate data and fitting an 6th degree polynomial to the smoothed data. The determined surface DS of the article A is provided by the coordinate data of the segments.

Figure 3J shows a defect D identified by comparing the generated surface GS and the determined surface DS of the article. Particularly, the defect D is identified based on a difference between the determined surface DS and the generated surface GS. In this example, the difference exceeds a predetermined threshold for the plate link side of the grouser.

Figure 3K shows a 3D representation of the generated surface GS of the article, from 32 measured cross-sectional profiles.

Figures 4A, 4B, 4C and 4D are photographs of straightening of a hot rolled steel profile P (i.e. an article), before inspecting by a method according to an exemplary embodiment.

Straightening of the hot rolled steel profile P, particularly a rail having a length of 108 m, is by rolling using a roller straightening machine RSM. Generally, roller straightening machines are used to straighten profiles, by alternately deforming the profile at decreasing strains therethrough. For hot rolled steel profiles, straightening is performed at relatively low temperatures (for example, below 100 °C such as 70 °C -80 °C), after hot rolling and cooling.

Roller straightening machines may also correct cross-sectional profile for example by reducing ellipticity and/or twist. During the alternate deformation, scale on the surfaces tends to spall but may remain on upper surfaces of the profile. The roller straightening machine RSM includes 5 loaded upper rolls UR1 to UR5 and 5 fixed lower rolls LR1 to LR5. The hot rolled steel profile P serpentines through the roller straightening machine RSM, thereby straightening the hot rolled steel profile P while scale spalls from the surfaces, remaining typically on the upper surfaces thereof. During straightening of a currently-rolled portion of the hot rolled steel profile P by the upper rolls UR1 to UR5 and 5 lower rolls LR1 to LR5, straightened portions of the hot rolled steel profile P extending beyond the roller straightening machine RSM vibrate due to rolling of the currently-rolled portion.

Figure 4A shows the hot rolled steel profile P fed fully through the roller straightening machine RSM. A leading end L of the hot rolled steel profile P is shown exiting the roller straightening machine RSM, just beyond the last upper roller UR5, at a speed of about 2 ms-1. An exit guide G guides the hot rolled steel profile P onto a conveyor C (not shown) and hence through an apparatus 20 according to an exemplary embodiment, as described with respect to Figures 5A to 5D, BA to 6D and 7A to 7D.

Figure 4B shows the hot rolled steel profile P fed fully through the roller straightening machine RSM. A trailing end T of the hot rolled steel profile P is shown entering the roller straightening machine RSM, just before the first lower roller LR1.

Figure 4C shows the hot rolled steel profile P exiting the roller straightening machine RSM. The trailing end T of the hot rolled steel profile P is shown fed through rollers UR4, LR5 and UR5. Note the position of the hot rolled steel profile P exiting the roller straightening machine RSM, just beyond the last upper roller UR5, relative to a hole H in an exit guide G. Figure 4D shows the hot rolled steel profile P after exiting the roller straightening machine RSM. The trailing end T of the hot rolled steel profile P is shown exiting the roller straightening machine RSM, just beyond the last upper roller UR5. Note the new position of the trailing end T of the hot rolled steel profile P exiting the roller straightening machine RSM, just beyond the last upper roller UR5, relative to a hole H in the exit guide G. Particularly, upon exiting the roller straightening machine RSM, the trailing end T of the hot rolled steel profile P falls down on to the conveyor C and bounces. This movement of the trailing end T of the hot rolled steel profile P is transmitted along the hot rolled steel profile P, resulting in vibration of that portion of the hot rolled steel profile P moving through the first measurement area of the apparatus 10. In addition, this vibration causes scale on the upper surface of that portion of the hot rolled steel profile P to jump therefrom, resulting in occlusions. Furthermore, as portions between the leading end L and the trailing end T of the hot rolled steel profile P land on the conveyor C, the relative flexibility of the hot rolled steel profile P in view of its length means that the hot rolled steel profile P tends to snake along the conveyor C. Hence, successive portions of the hot rolled steel profile P moving through the first measurement area of the apparatus 10 are situated at different relative positions therein. In addition, vibration due to the straightening of the currently-rolled portion of the hot rolled steel profile P by the upper rolls UR1 -UR5 and 5 lower rolls LR1 -LR5, is transmitted to straightened portions of the hot rolled steel profile P extending beyond the roller straightening machine RSM.

Figures 5A, 5B, 5C and 5D are photographs of inspecting of a straightened hot rolled steel profile P, by a method according to an exemplary embodiment, using an apparatus 20 according to an exemplary embodiment. The straightened hot rolled steel profile P is moved from the roller straightening machine RSM, as described above with reference to Figures 4A, 4B, 4C and 4D, by the conveyor C, in the first dimension through a first measurement area of the apparatus 20. Figures 5A, 5B, 5C and 5D show the hot rolled steel profile P moving towards and through the first measurement area.

The apparatus 20 is generally as described with respect to the apparatus 10. The apparatus 20 comprises a set of 6 Wenglor weCat3D MLWL175 optical (laser) non-contact profilometers using triangulation arranged such that the respective measurement areas are substantially coplanar in the second and third dimensions and substantially equispaced on the locus of a circle (i.e. by 60°). By using six profilometers, there is some overlap between segments measured on adjacent profilometers, thereby giving higher resolution in regions of overlap, while allowing for measurement of complex cross-sectional profiles. The laser has a wavelength of 450 nm (i.e. blue, shown as a blue line), giving increased resistance to extraneous light and high-speed while suitable for use on metals. The MLWL175 has a working range in Z of 600 to 1400 mm, a measuring range in Z of 800 mm and a measuring ranging X of 450 to 720 mm. The resolution in Z is between 28 and 67 pm and in X between 20 and 35 and 361 pm. About 2,000 points (i.e. coordinate data) may be acquired per second at a rate of 6 kHz, giving 12 million points per second.

The computer includes dual Xeon 3.0 Ghz processors, each having 14 cores for processing 28 threads i.e. a total of 56 threads, 256 GB RAM and a 30 TB HDD, to process the coordinate data from the 6 MLWL175 profilometers in real-time, thereby providing real-time inspection. Each MLWL175 profilometer is coupled to the computer using a 1 Gigabit ethernet cable to handle the data rate, each on a separate network to provide accurate network time stamps. Between 4,000 and 8,000 hot rolled steel profiles, each having a length in a range from 12 m to over 100 m, may be inspected weekly, moving through the measurement areas at a speed of about 2 ms-1 Figure 5A shows a leading end L of the hot rolled steel profile P having just moved through first measurement area, at a speed of about 2 ms-1. The leading end L of the hot rolled steel profile P is cantilevered beyond a lower roller 200. A portion of the hot rolled steel profile P, while vibration is transmitted along the hot rolled steel profile P from the roller straightening machine RSM, resulting in displacements of the hot rolled steel profile P, while scale on the upper surface of the hot rolled steel profile P jumps thereon, providing occlusions.

Figure 5B shows a trailing end T of the hot rolled steel profile P approaching the apparatus 20, according to an exemplary embodiment. The hot rolled steel profile P has fully exited the roller straightening machine RSM.

Figure 5C shows the trailing end T of the hot rolled steel profile P further approaching the apparatus 10. The trailing end T of the hot rolled steel profile P is cantilevered behind the lower roller 200.

Figure 5D shows the trailing end T of the hot rolled steel profile P about to move through the first measurement area, at a speed of about 2 ms-1. The trailing end T of the hot rolled steel profile P is on the lower roller 200. When the trailing end T of the hot rolled steel profile P moves beyond the lower roller 200, the trailing end T of the hot rolled steel profile P deflects downwards as it moves through the first measurement area.

Figures 6A, 6B, 6C and 6D are photographs of inspecting of a straightened hot rolled steel profile P, by a method according to an exemplary embodiment, using the apparatus 20 according to an exemplary embodiment.

Figures 6A, 6B, 6C and 6D are generally similar to Figures 5A, 5B, 5C and 5D. In contrast, Figures 6A, 6B, 6C and 6D show the hot rolled steel profile P moving through and away from the first measurement area.

Figure 7A schematically depicts a method according to an exemplary embodiment. The method is generally as described with respect to the method of Figures 3A to 3K. In this example, the set of optical profilometers includes six optical profilometers (Laser 1 to Laser 6). Generally, data from the respective optical profilometers are processed separately and in parallel, for example on separate threads, for speed. In this way, the method may be performed in real-time.

At 5701 (GEOMETRY), geometry correction is performed, generally as described with respect to Figure 3C. In more detail, the lasers are positioned around the product and provide measurements relative to each laser. This thread rotates then translates each laser as though it was vertically above the product so each now has a common coordinate system. In this example, it also masks off a measurement rectangle to exclude obstructions such as metal work etc. in the background. Optionally, correction to cope with non-parallel lasers maybe included, although in general being parallel is preferred.

At S702 (TRACKING), start and end detection of the articles is performed. In more detail, the lasers measure continuously (while rolling) but we only want to log bars. So tracking decides when valid measurements start and end. Bar sequence number is incremented. False triggers and/or gaps in measurements are rejected.

At S703 (POSITION), optional readings from a speed/length sensor enable respective lengths of the bars to be drawn to scale and identify where a defect is along the length of the bar. Additionally and/or alternatively, position may be calculated from scan number and scan frequency, for example.

At 5704 (AGGREGATE), the data from each laser is aggregated into a full set of data, to provide a full profile.

DISK QUEUE (Not shown) is an optional buffer to isolate hard real time code from soft real time code. After position thread, a large disk based buffer allows all following threads to lag several seconds behind the hard real time processing. In this way, low performance computing hardware may be used.

At S705 (DESPECKLE), outlier groups of points, seemingly not related to bar surface. i.e. dust and flakes of scale, are removed, generally described with respect to Figure 3D.

At 5706 (REGISTER) the master laser is debounced, generally as described with respect to Figures 3E to 3H, thereby aligning a top flat surface and Left or Right hand edge to a zero point datum. All other lasers are rotated and translated to match the master after allowing for time difference in the scans. The master may be assigned manually or maybe assigned automatically, for example dynamically.

At 5707 (DEFECT DETECT), the surface of the bar is generated and defects identified, generally as described with respect to Figures 31 and 3J. Particularly, deviations from a smoothed surface are identified. In this example, this is divided into 4 parallel threads per laser to spread CPU load.

At 5708 (ANALYSE), logging, evaluation and reporting are performed.

Figure 7B is a perspective view of raw data, before correcting, for a hot rolled steel profile, particularly a cathode collector bar profile, inspected using the apparatus 20, as described above. For clarity of illustration, data from a single profilometer is shown. The cathode collector bar has a square cross-sectional having radiused corners. The raw data are represented by slices, each slice comprising points measured by the profilometers, such that each slice corresponds with a measured cross-sectional profile at a particular time. The spacing between adjacent slices is about 0.33 mm, given a measurement rate of 6 kHz and a conveying speed of about 2 ms-1. About 300 to 400 slices are shown. The raw data, however show spurious data points (i.e. outliers) due to occlusions such as loose, moving scale while displacement, for example bouncing, of the bar during conveying results in marked undulations, including a peak corresponding with a maximum displacement of about 25% of the height of the bar over about 30 slices i.e. about 5 ms.

Figure 7C is a perspective view of the corrected data, corrected using the method of Figure 7A. The corrected data may be considered to be the determined surface of the article. In contrast to the raw data of Figure 7B, the spurious data points due to the occlusions have been removed and displacement corrected for, such that the determined surface for the cathode collector bar has a square cross-sectional profile having radiused corners.

Figure 7D is a cross-sectional profile from the corrected data of Figure 7C, showing the determined surface and the generated surface of the cross-sectional profile, with an enlarged view inset. A defect D at a radiused corner is identified based on a difference between the determined surface and the generated surface. In this example, the difference exceeds a predetermined threshold for the cathode bar.

Figure 8A is a perspective view of a hot rolled steel profile, particularly a single grouser, naming parts thereof. Figure 8B is a cross-section view of the hot rolled steel profile showing relative incidence of surface defects. About half of all defects are identified on the leading edge of the spike and over one third of the defects identified on the trailing side of the spike and the plate spike side. Conventionally, it is difficult to inspect particularly the trailing side the spike plate side of the spike, which are usually oriented downwards after hot rolling. However, the apparatus and method described herein may inspect all surfaces of the grouser in real-time and hence improve identification of defects. Particularly, by identifying defects in real-time, remedial action may be taken to prevent re-occurrence of the defects during subsequent hot rolling of other hot rolled steel profiles.

Figure 8C is a photograph of a typical surface defect Din the leading toe of the hot rolled steel profile; and Figure 8D is a photograph of a typical surface defect D in the leading edge of spike of the hot rolled steel profile. Conventionally, such defects are identified only by visual inspection of only a proportion of a given length of the hot rolled steel profile. For example, only 20% of the length of the hot rolled steel profile may be inspected. In contrast, the apparatus and methods described herein may inspect the full length of the hot rolled steel profile, thereby improving identification of defects and hence enhancing quality.

Figure 9A is a perspective view of corrected data, corrected using the method of Figure 7A, for a hot rolled steel profile and Figure 9B is a photograph of the hot rolled steel profile of Figure 9A.

In this example, a large defect D is apparent in the corrected data for a plate link side of a single grouser, due to a rolled in piece of debris, such as steel plate. This defect was identified in real-time using the apparatus 20 and the method as described herein and subsequently confirmed by visual inspection, allowing remedial action to be taken to prevent re-occurrence.

Figure 9C is a perspective view of corrected data, corrected using the method of Figure 7A, for a hot rolled steel profile; and Figure 9D is a photograph of the hot rolled steel profile of Figure 9C.

In this example, a relatively shallow but elongated defect D in the corrected data for a plate link side of a single grouser, due to a rolled in piece of debris, such as a wire. This defect was identified in real-time using the apparatus 20 and the method as described herein and subsequently confirmed by visual inspection, allowing remedial action to be taken to prevent re-occurrence.

Figure 10 schematically depicts a surface quality index of a hot rolled steel profile.

As described previously, with reference to Table 1, the surface quality index may be defined according to a proportion, a distribution and a size of surface defects (also known as discontinuities) of the hot rolled steel profile, as shown schematically in Figure 10.

Figures 11A to 11C are photographs of hot rolled steel profiles having surface defects in surfaces thereof and Figure 12 is a photograph of a hot rolled steel profile according to an exemplary embodiment.

Particularly, Figures 11A to 11C show fork flats Fl to F3, respectively, having surface quality indices of at most 2, due to rolled in scale S and impressions I due to scale.

In contrast, Figure 12 shows a fork flat F4 having a surface quality index of at least 8.

Figure 13A is a photograph of a hot rolled steel profile having surface defects in a surface thereof and Figure 13B is a photograph of a hot rolled steel profile according to an exemplary embodiment.

Particularly, Figure 13A shows a fork flat F5 having a surface quality index of at most 4, due to rolled in scale S and impressions I due to scale.

In contrast, Figure 13B shows a fork flat F6 having a surface quality index of at least 8.

Figure 14 schematically depicts a cross-section of a bulb flat according to an exemplary 20 embodiment.

The cross-section is asymmetric, being generally rectangular and having a bulb at one side. A width b is in a range from 160 mm to 430 mm and a thickness t is in a range from 7 mm to 20 mm. Bulb flats may have lengths in a range from 6 m to 18 m.

Figure 15 schematically depicts a cross-section of a crane rail according to an exemplary embodiment. Other sizes may be provided.

Figures 16A to 16C schematically depict cross-sections of track shoe profiles according to exemplary embodiments.

Particularly, Figures 16A to 16C show cross-sections of single, double and triple grouser track shoe profiles, typically having widths W in a range from 173 mm to 369 mm. The cross-sections are asymmetric, having one, two and three protrusions upstanding from generally rectangular cross-sections, respectively. Opposed sides are arranged to mate with adjacent similar track shoes, having a male convex part and a female concave part, respectively.

Grouser heights H may typically be in a range from 19 to 102mm. Track shoe thickness T may typically be in a range from 7.9 to 30 mm.

Figures 17A to 17D schematically depict cross-sections of cutting edge profiles according to exemplary embodiments.

Particularly, Figures 17A to 17D show cross-sections of a single bevel flat, a double bevel flat, a grader bars and an arrowhead flat, respectively.

W may typically be from 152 to 480 mm, T typically from 12.7 to 60 mm, A typically from 22.5 to 25° and B typically from 23.6 to 98.7 mm.

Figure 18 schematically depicts a cross-section of a top hat profile according to an exemplary embodiment. Various sizes may be provided.

Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at most some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS1. A method of inspecting a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method implemented, at least in part, by a computer including a processor and a memory, the method comprising: providing a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; moving, by a conveyor, the article in the first dimension through the first measurement area; acquiring, by the first profilometer, a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the first measured cross-sectional profile; determining, by the computer, the first part of the surface of the article based, at least in part, on the first segment; generating, by the computer, a generated first part of the surface of the article using the determined first part of the surface; comparing, by the computer, the determined first part of the surface and the generated first part of the surface; and inspecting, by the computer, the article based on a first result of the comparing.
2. The method according to claim 1, wherein generating, by the computer, the generated first part of the surface of the article using the determined first part of the surface comprises modelling the determined first part of the surface.
3. The method according to claim 2, wherein modelling the determined first part of the surface comprises ab initio modelling the determined first part of the surface.
4. The method according to any previous claim, wherein generating, by the computer, the generated first part of the surface of the article using the determined first part of the surface comprises fitting a first curve of a set of curves, in the second and/or the third dimensions, to the first set of coordinate data of the first segment of the first measured cross-sectional profile.
5. The method according to claim 4, wherein fitting the first curve of the set of curves, in the second and/or third dimensions, to the first set of coordinate data of the first segment of the first measured cross-sectional profile comprises smoothing the first set of coordinate data of the first segment of the first measured cross-sectional profile.
6. The method according to claim 5, wherein smoothing the first set of coordinate data of the first segment of the first measured cross-sectional profile comprises moving average smoothing.
7. The method according to any of claims 4 to 6, wherein the first curve comprises an Nth degree polynomial, wherein N is a natural number greater than or equal to 1, in a range from 2 to 10, preferably in a range from 2 to 8, more preferably in a range from 3 to 7.
8. The method according to any previous claim, wherein inspecting the article based on the first result of the comparing comprises identifying a first defect based, at least in part, on a first difference between the determined first part of the surface and the generated first part of the surface.
9. The method according to any previous claim, wherein providing the set of non-contact profilometers comprises providing the set of non-contact profilometers including a second profilometer, for example a second laser profilometer, defining a second measurement area; wherein the method comprises: acquiring, by the first profilometer, a first segment of a set of segments of a second measured cross-sectional profile of the set of measured cross-sectional profiles of the moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of a second part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the second measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the second measured cross-sectional profile; determining, by the computer, the second part of the surface of the article based, at least in part, on the first segment; generating, by the computer, a generated second part of the surface of the article using the determined second part of the surface; comparing, by the computer, the determined second part of the surface and the generated second part of the surface; and inspecting, by the computer, the article based on the first result and/or a second result of the comparing.
10. The method according to any previous claim, comprising: acquiring, by the first profilometer, a first segment of a set of segments of a second measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and third dimensions, of a second part of the surface of the article; transmitting, by the first profilometer, the first set of coordinate data of the first segment of the second measured cross-sectional profile; receiving, by the computer, the first set of coordinate data of the first segment of the second measured cross-sectional profile; determining, by the computer, the second part of the surface of the article based, at least in part, on the first segment.generating, by the computer, a generated second part of the surface of the article using the determined second part of the surface; comparing, by the computer, the determined second part of the surface and the generated second part of the surface; and inspecting, by the computer, the article based on a second result of the comparing.
11. The method according to any previous claim, comprising: occluding, at least in part, the first part of the surface of the moving article by a first occlusion in the first measurement area; and correcting, by the computer, the first segment for the first occlusion, thereby providing a corrected first segment comprising a first set of corrected coordinate data.
12. The method according to any previous claim, comprising: displacing the moving article by a first displacement of a set of displacements in the second and/or third dimension; and correcting, by the computer, the first segment for the first displacement by a first correction, thereby providing a corrected first segment comprising a first set of corrected coordinate data of the first measured cross-sectional profile.
13. An apparatus for inspecting a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the apparatus comprising: a set of non-contact profilometers including a first profilometer, for example a first optical profilometer, defining a first measurement area; a conveyor configured to move the article in the first dimension through the first measurement area; and a computer including a processor and a memory; wherein the first profilometer is configured to: acquire a first segment of a set of segments of a first measured cross-sectional profile of the set of measured cross-sectional profiles of the displaced, moving article in the first measurement area, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; and transmit the first set of coordinate data of the first segment of the first measured cross-sectional profile to the computer; and wherein the computer is configured to: receive the first set of coordinate data of the first segment of the first measured cross-sectional profile; determine the first part of the surface of the article based, at least in part, on the first segment; generate a generated first part of the surface of the article using the determined first part of the surface; compare the determined first part of the surface and the generated first part of the surface. and inspect the article based on a first result of the comparing.
14. A computer for inspecting, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the computer comprising a processor and a memory, wherein the computer is configured to: receive a first set of coordinate data of a first segment of a set of segments of a first measured cross-sectional profile of a set of measured cross-sectional profiles of the moving article, wherein the first segment comprises a first set of coordinate data, in the second and the third dimensions, of the first part of the surface of the article; receive the first set of coordinate data of the first segment of the first measured cross-sectional profile; determine the first part of the surface of the article based, at least in part, on the first segment; generate a generated first part of the surface of the article using the determined first part of the surface; compare the determined first part of the surface and the generated first part of the surface; and inspect the article based on a first result of the comparing.
15. A tangible non-transient computer-readable storage medium having recorded thereon instructions which when implemented by computer device including at least a processor and a memory, cause the computer device to perform a method of inspecting, at least in part, a first part of a surface of an article having an axial length extending in a first dimension and a cross-sectional profile in mutually transverse second and third dimensions, the method according to any of claims 1 to 12.