Broken Wheel Detection System

• US 20180237041A1
• Filed: 02/22/2018
• Published: 08/23/2018
• Est. Priority Date: 02/22/2017
• Status: Active Grant

• Current Assignee: Tetra Tech Incorporated
• Original Assignee: Tetra Tech Incorporated
• Inventors: Mesher, Darel
• Granted Patent: US 10,435,052 B2
• Time in Patent Office: Days
• CPC Class Codes: B61L 23/00 Control, warning or like safety means along the route or between vehicles or trains
• CPC Class Codes: B61L 27/40 Handling position reports or trackside vehicle data
• CPC Class Codes: B61L 27/57 for vehicles or trains, e.g. trackside supervision of train conditions
• CPC Class Codes: B61L 9/04 electric
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence
• 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: G01B 11/2518 Projection by scanning of the object
• CPC Class Codes: G01B 11/2522 the position of the object changing and being recorded
• CPC Class Codes: G01B 11/2545 with one projection direction and several detection directions, e.g. stereo
• CPC Class Codes: G01M 17/10 Suspensions, axles or wheels
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/20068 Projection on vertical or horizontal image axis
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 2207/30236 Traffic on road, railway or crossing
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/56 : provided with illuminating means
• CPC Class Codes: H04N 23/57 : Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices

Abstract

A broken wheel detection system for detecting broken wheels on rail vehicles even when such vehicles are moving at a high rate of speed.

Claims

1. A broken wheel detection apparatus for detecting broken wheels on rail cars while a rail car is in motion passing by the broken wheel detection apparatus, the apparatus comprising:

a first rail sensor assembly comprising a first structured light generator directed toward a first section of a first rail, and a first digital area scan camera directed to a first wheel assessment zone which includes the first section of the first rail; and

a processor in communication with the first rail sensor assembly wherein the processor controls the operation of the first structured light generator and the first digital area scan camera, and wherein the processor includes an algorithm for detecting and recording a defect of a wheel on a rail car as such rail car passes by the broken wheel detection apparatus, the algorithm comprising the steps of;

a. detecting a passing rail car;

b. obtaining a first plurality of elevation scan frames of a wheel of the rail car using the first digital area scan camera;

c. identifying parallel structured light lines in the first plurality of elevation scan frames;

d. recording on the processor the position, length and orientation of some of the structured light lines in each frame of the first plurality of elevation scan frames; and

e. comparing the position, length and orientation of the recorded structured light lines in each of the first plurality of elevation scan frames to determine whether all recorded corresponding structured light lines maintain the same position, length and orientation for each of the first plurality of elevation scan frames.

2. The broken wheel detection apparatus of claim 1 wherein the first rail sensor assembly further comprises a second structured light generator directed to a second section of the first rail and a second digital area scan camera directed to a second wheel assessment zone which includes the second section of the first rail, wherein the second structured light generator and the second digital area scan camera are in communication with and controlled by the processor, and wherein the algorithm step of e. comparing the position, length and orientation of the recorded structured light lines in each of the first plurality of elevation scan frames to determine whether all recorded corresponding structured light lines maintain the same position, length and orientation for each of the first plurality of elevation scan frames comprises the steps of:

f. obtaining a second plurality of elevation scan frames of the wheel of the rail car using the second digital area scan camera;

g. identifying parallel structured light lines in the second plurality of elevation scan frames;

h. recording on the processor the position, length and orientation of some of the structured light lines in each frame of the second plurality of elevation scan frames; and

i. comparing the position, length and orientation of the recorded structured light lines in each of the first plurality of elevation scan frames and the second plurality of elevation scan frames to determine whether all recorded corresponding structured light lines maintain the same position, length and orientation for each of the first plurality of elevation scan frames and the second plurality of elevation scan frames.

3. The broken wheel detection apparatus of claim 1 further comprising a wheel detector in communication with the processor.

4. The broken wheel detection apparatus of claim 1 further comprising an Automatic Equipment Identification (AEI) device in communication with the processor.

5. The broken wheel detection apparatus of claim 1 wherein the algorithm for detecting and recording a defect of a wheel on a rail car as such rail car passes by the broken wheel detection apparatus further comprises the step of:

f. recording on the processor a defect indication that the wheel of the rail car includes no defects if the position, length and orientation of each of the recorded structured light lines in the first plurality of elevation scan frames is determined by the processor to be the same for each elevation scan frame;

or recording on the processor a defect indication that the wheel of the rail car includes a defect if the position, length or orientation of any of the recorded structured light lines in the first plurality of elevation scan frames is determined by the processor to be different in any of the elevation scan frames.

6. The broken wheel detection apparatus of claim 2 wherein the algorithm for detecting and recording a defect of a wheel on a rail car as such rail car passes by the broken wheel detection apparatus further comprises the steps of:

j. recording on the processor a defect indication that the wheel of the rail car includes no defects if the position, length and orientation of each of the recorded structured light lines in the first plurality of elevation scan frames and the second plurality of elevation scan frames is determined by the processor to be the same for each elevation scan frame;

or recording on the processor a defect indication that the wheel of the rail car includes a defect if the position, length or orientation of any of the recorded structured light lines in the first plurality of elevation scan frames or the second plurality of elevation scan frames is determined by the processor to be different in any of the elevation scan frames.

7. The broken wheel detection apparatus of claim 4 wherein the algorithm for detecting and recording a defect of a wheel on a rail car as such rail car passes by the broken wheel detection apparatus further comprises the steps of:

k. obtaining the identity of the specific rail car on which the wheel of the rail car is mounted using information from the AEI device;

l. obtaining the specific wheel count calculated by the processor; and

m. recording the identity of the specific rail car on which the wheel of the rail car is mounted, the specific wheel count, and the defect indication on the processor to associate such data with the wheel of the rail car.

8. A method for detecting broken wheels on rail cars while a rail car is in motion, which comprises:

a. detecting a rail car in motion before it passes by a broken wheel detection apparatus using a detection device in communication with a processor;

b. projecting structured light lines toward the rail car as it passes by the broken wheel detection apparatus using a light generator in communication with the processor;

c. obtaining a first plurality of elevation scan frames of a wheel of the rail car using a first digital area scan camera in communication with the processor;

d. identifying parallel structured light lines in the first plurality of elevation scan frames using the processor;

e. recording on the processor the position, length and orientation of some of the structured light lines in the first plurality of elevation scan frames; and

f. comparing the position, length and orientation of the recorded structured light lines in each of the first plurality of elevation scan frames using the processor to determine whether all recorded corresponding structured light lines maintain the same position, length and orientation for each of the first plurality of elevation scan frames.

9. The method of claim 8 wherein the step of comparing the position, length and orientation of the recorded structured light lines in each of the first plurality of elevation scan frames using the processor to determine whether all recorded corresponding structured light lines maintain the same position, length and orientation for each of the first plurality of elevation scan frames comprises the steps of:

g. obtaining a second plurality of elevation scan frames of the wheel of the rail car using a second digital area scan camera in communication with the processor;

h. identifying parallel structured light lines in the second plurality of elevation scan frames using the processor;

i. recording on the processor the position, length and orientation of some of the structured light lines in the second plurality of elevation scan frames; and

j. comparing the position, length and orientation of the recorded structured light lines in the first plurality of elevation scan frames and the second plurality of elevation scan frames using the processor to determine whether all recorded corresponding structured light lines maintain the same position, length and orientation for each of the first plurality of elevation scan frames and the second plurality of elevation scan frames.

10. The method of claim 9 further comprising the step of:

k. recording on the processor a defect indication that the wheel of the rail car includes no defects if the position, length and orientation of each of the recorded structured light lines in the first plurality of elevation scan frames and the second plurality of elevation scan frames is determined by the processor to be the same for each elevation scan frame;

or recording on the processor a defect indication that the wheel of the rail car includes a defect if the position, length or orientation of any of the recorded structured light lines in the first plurality of elevation scan frames or the second plurality of elevation scan frames is determined by the processor to be different in any of the elevation scan frames.

11. The method of claim 10 further comprising the steps of:

l. obtaining the identity of the specific rail car on which the wheel of the rail car is mounted using information from an AEI device in communication with the processor.

m. obtaining the specific wheel count calculated by the processor; and

n. recording the identity of the specific rail car on which the wheel of the rail car is mounted, the specific wheel count, and the defect indication on the processor to associate such data with the wheel of the rail car.

12. The method of claim 8 wherein the step of c. obtaining a first plurality of elevation scan frames of a wheel of the rail car using a first digital area scan camera in communication with the processor further comprises the step of masking portions of the first plurality of elevation scan frames except for the rim edge of the wheel of the rail car using the processor.

13. The method of claim 12 wherein the step of masking portions of the first plurality of elevation scan frames except for the rim edge of the wheel of the rail car using the processor further comprises the step of identifying three wheel rim regions in the first plurality of elevation scan frames using the processor, such wheel rim regions including a wheel rim left region, a wheel rim right region, and a wheel rim bottom region.

14. The method of claim 13 wherein the step of identifying parallel structured light lines in the first plurality of elevation scan frames using the processor further comprises the step of identifying parallel structured light lines in the wheel rim left region and the wheel rim right region;

and wherein the step of recording on the processor the position, length and orientation of some of the structured light lines in the first plurality of elevation scan frames further comprises the step of recording on the processor the position, length and orientation of each structured light line for the wheel rim right region and the wheel rim left region.

15. The method of claim 14 further comprising the step of wirelessly transmitting the recorded data regarding the identity of the specific rail car on which the wheel of the rail car is mounted, the specific wheel count, and the defect indication to be received at a remote location.

16. The method of claim 12 wherein the step of detecting a rail car in motion before it passes by a broken wheel detection apparatus using a detection device in communication with a processor further comprises the steps of storing the last elevation scan frame before the wheel of the rail car appears for the first time as one of the elevation scan frames of the first plurality of scan frames so that the stored elevation scan frame can be used as a background frame;

and removing any visible features present in the background frame from the first elevation scan frame of the first plurality of elevation scan frames.

17. The method of claim 11 wherein the method further comprises the step of repeating steps a. through n. with a second wheel of the rail car passing by the broken wheel detection apparatus.