SYSTEM AND METHOD FOR INSPECTING THE GEOMETRIC PARAMETERS OF THE WHEELS OF RAILWAY VEHICLES

• US 20160282108A1
• Filed: 03/18/2014
• Published: 09/29/2016
• Est. Priority Date: 03/18/2013
• Status: Active Grant

• Current Assignee: Metro De Medellin Ltda (Government of Colombia)
• Original Assignee: Universidad Eafit
• Inventors: MARTINOD RESTREPO, RONALD MAURICIO, DAZ, ADALBERTO G., ARANGO, IVN D., BETANCUR GIRALDO, GERMAN REN, CASTAEDA HEREDIA, LEONEL FRANCISCO
• Granted Patent: US 10,088,300 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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, characterized by:

a. generating a light beam by a structured light source on the partial transverse section of the wheel, so that the light beam impacts on the wheel as a line of light;

b. capturing an image of the projected line of light on the transverse section of the wheel through a CCD camera;

c. converting the image in a partial profilogram of the transverse section wheel by an artificial vision system;

d. geometrically correcting the partial profilogram through a transformation of coordinate systems; and

e. reconstructing the partial profilogram by a geometric overlap of the matching partial profilogram sections with the reference profilogram of a standard wheel.

2. The measuring method of claim 1, wherein the partial reconstruction of a partial profilogram of a transverse section of a wheel not recorded in an image is done by superimposing overlapping corresponding sections belonging to a partial profilogram and a reference profilogram.

3. The measuring method of claim 1, wherein the horizontal distance between the inner side of the wheel and the top of the flange, and the horizontal distance between the outer side of the wheel and the top of the flange allow positioning the partial profilogram (320) relative to the reference profilogram (400).

4. The measuring method of claim 1, wherein the overlap of the corresponding sections is performed by selected numerical processes from the set consisting of:

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

5. The measuring method of claim 1, wherein first order or higher numerical interpolation methods are used to find the geometric parameters of the wheel profile.

6. The measuring method of claim 1, wherein the geometric parameters of the wheel profile are selected from the group consisting of:

flange height, flange thickness, indirect measurement of the angle of the flange, difference in profile reduction, and difference in area reduction.

7. The measuring 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 the flange height.

8. The measuring method of claim 1, wherein prior to step (a), the following step comprises:

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

9. The measuring method of claim 8, wherein the partial profilogram of the wheel at an angle of attack is geometrically corrected by a coordinate system transformation.

10. The measuring method of claim 8, wherein the measurements are stored in a database in order to allow for historical analysis of the signals from each wheel for analyzing trends, predicting wheel condition, and inferring deterioration rates.

11. The method of claim 4, wherein a first-order or higher numerical interpolation process is applied to find the control points in a reconstructed profilogram, in order to obtain the values of the geometric parameters.

12. A system for measuring geometric parameters of wheel profiles of rolling stock running on a track on railways, characterized by

a. a structured light source that generates a beam of light on a partial transverse section of the wheel;

b. an element for recording the light emitted by the structured light source; and

c. a system of data acquisition that transmits information from the camera to a computer network that centralizes, manages, and stores information of the measurement of geometric parameters of the wheel profile of rolling stock.

13. The system of claim 12, wherein the structured light source is a flat beam laser generator type.

14. The system of claim 12, wherein the recording element is a capture camera.

15. The system of claim 12, wherein the arrangement provided by the structured light source projects a line of light that impacts the surface of the transverse section of the wheel.

16. The system of claim 12, wherein the data acquisition system can integrate other measurement data from other measurement systems by adding modules.

17. The system of claim 12, wherein the data acquisition system enables the automatic identification of vehicles, such as vehicle type, number of cars, number of axles, number of wheels.

18. The system of claim 12, 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.

19. The system of claim 12, 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.

20. The system of claim 12, wherein the data acquisition system generates statistics, trends and predictions of wheel conditions and allows for inferring deterioration rates.

21. The system of claim 12, wherein said system can be implemented on various sections of the track.