System and method for inspecting the geometric parameters of the wheels of railway vehicles

• US 10,088,300 B2
• Filed: 03/18/2014
• Issued: 10/02/2018
• Est. Priority Date: 03/18/2013
• Status: Active Grant

• Current Assignee: Metro De Medellin Ltda (Government of Colombia)
• Original Assignee: Metro De Medellin Ltda (Government of Colombia), Universidad Eafit
• Inventors: Martinod Restrepo, Ronald Mauricio, Betancur Giraldo, German Rene, Castaneda Heredia, Leonel Francisco, Diaz, Adalberto G., Arango, Ivan D.
• Primary Examiner(s): Tsai, Tsung-Yin
• Application Number:
  US14/778,239
• Publication Number:
  US 20160282108A1
• Time in Patent Office: 1,659 Days
• CPC Class Codes: B61K 9/12 Measuring or surveying wheel-rims measuring techniques G01
• CPC Class Codes: G01B 11/10 of objects while moving
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G01M 17/013 Wheels
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume
• CPC Class Codes: H04N 25/71 Charge-coupled device [CCD] sensors; Charge-transfer registers specially adapted for CCD sensors

Abstract

The present invention relates to a system and method for the automated inspection of geometric parameters of railway wheels rolling on a track by artificial vision techniques. The present invention uses a structured light source (10) that illuminates a line of light (12) upon a fraction of the surface of revolution (3) of a wheel (1), a CCD camera (20), which captures an image (21) of the illuminated area, and a data processing system that records, digitalizes, geometrically corrects and reconstructs information of the surface of revolution (3) that is not recorded in the image (21), in order to obtain a numeric description of the complete transverse section of the wheel (1) represented by a reconstructed profilogram (500) for calculating the geometric parameters of the wheel (1).

Claims

1. A method for measuring geometric parameters of wheel profiles of rolling stock running on a track on railways, comprising:

a. generating a light beam by one structured light source on a partial transverse section of a wheel comprising a tread surface and a flange, so that the light beam impacts on a portion of the tread surface and a portion of the flange of the wheel as a line of light;

b. capturing an image of the projected line of light on the transverse section of the wheel with one recording element;

c. converting a captured image of the partial transverse section of the wheel in a partial profilogram by an artificial vision system, wherein the partial profilogram comprises a flange top;

d. identifying a reference profilogram, wherein the reference profilogram comprises a flange top which is the same flange top than the partial profilogram;

e. constructing a reconstructed profilogram by completing the partial profilogram with the reference profilogram, wherein the missing portions of the partial profilogram are provided by the reference profilogram.

2. The method of claim 1, wherein a horizontal distance between an inner side of the wheel and the flange top, and a horizontal distance between an outer side of the wheel and the flange top remain fixed, allowing the construction of the reconstructed profilogram.

3. The method of claim 1, wherein the construction of the reconstructed profilogram is performed by numerical processes selected from the group consisting of:

computational geometry, statistical processes, and pattern recognition processes with artificial intelligence using artificial neural networks.

4. The method of claim 1, which also comprises measuring the wheel diameter by the difference between the distances of circumferential radius of the flange top and a flange height (hs).

5. The method of claim 1, wherein prior to the light generating step (a), the method comprises the following step:

measuring an angle of a transverse axis of the wheel in relation to a transverse axis of the rail by an arrangement of distance sensors, measuring the distances inside of the wheel together with the geometrical arrangement of said sensors.

6. The method of claim 1, wherein the wheel comprises a width of the wheel, and the width of the wheel remains fixed, allowing the construction of the reconstructed profilogram.

7. The method of claim 1, wherein the missing sections of the partial profilogram correspond to a section of the flange and a section of the outer fraction of the tread surface provided by the reference profilogram.

8. A system for measuring geometric parameters of wheel profiles of rolling stock running on a track on railways, comprising:

a. an autonomous array of recording elements consisting of;

i. one structured light source that generates a light beam on a partial transverse section of the wheel, so that the light beam impacts on the wheel as a line of light; and

ii. one element for capturing an image of the partial transverse section of the wheel lighted by the structured light source; and

b. a system of data acquisition that;

i. transmits information from the autonomous array to a computer network, wherein the computer network geometrically corrects a partial profilogram through a transformation of coordinate systems; and

ii. constructs a reconstructed profilogram by identifying a reference profilogram based on the partial profilogram, and completing the missing portions of the partial profilogram provided by the reference profilogram.

9. The system of claim 8, wherein the structured light source is a flat beam laser generator type.

10. The system of claim 8, wherein the element for capturing an image is a capture camera.

11. The system of claim 8, wherein the data acquisition system is connected to an array of non-contact distance sensors disposed transversely on the track to measure the distance between the inner sides of the wheels of an axle.

12. The system of claim 8, wherein the data acquisition system is connected to an array of distance sensors arranged transversely on the track to measure the angle of attack of a wheel.