Wheel profile sensor

• US 5,793,492 A
• Filed: 01/24/1997
• Issued: 08/11/1998
• Est. Priority Date: 01/24/1997
• Status: Expired due to Term

• Current Assignee: Loram Maintenance of Way, Inc.
• Original Assignee: Loram Maintenance of Way, Inc.
• Inventors: Vanaki, Hassan
• Primary Examiner(s): Rosenberger, Richard A.
• Application Number:
  US08/788,019
• Time in Patent Office: 564 Days
• Field of Search: 356/376, 356/384, 356/386
• US Class Current: 356/613
• CPC Class Codes: G01B 11/105 using photoelectric detection means
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence

Abstract

The present invention is a method and measurement apparatus for measuring the profile of a railway wheel while the railway wheel is in rolling motion on a rail. The railway wheel has a gage side and a field side and a circumferentially defined running surface and flange. The measurement apparatus comprises a first sensor means that is disposed on the field side of the railway wheel and which is disposed at an included angle with respect to the rail that is less than orthogonal senses the profile of the running surface and flange of the railway wheel at a point on the circumference. A second sensor means is disposed on the gage side of the railway wheel and senses selected wheel parameters. A controller is operably communicatively coupled to the first and second sensor means. The controller activates the first sensor means responsive to the detection of the presence of a railway wheel and applies the selected railway wheel parameters sensed by the second sensor means to the wheel profile sensed by the first sensor means to generate an actual profile measurement of the railway wheel running surface and flange taken along a plane defined by a radial section of the railway wheel.

Claims

1. Measurement apparatus for measuring the profile of a railway wheel while said railway wheel is in rolling motion on a rail, said railway wheel having a gage side and a field side, a gage circumference being defined on the gage side thereof, and said railway wheel having a circumferentially defined running surface and flange, comprising:

first sensor means having an emitter and an associated receiver being disposed on the field side of the railway wheel and being disposed at an included angle with respect to the rail that is less than orthogonal for sensing the profile of the running surface and flange of the railway wheel at a point on circumference thereof;

second sensor means having at least one emitter and at least an associated receiver being disposed on the gage side of the railway wheel for sensing a plurality of gage points on the gage circumference of the railway wheel; and

a control means operably communicatively coupled to the first and second means for activating the first sensor means responsive to the detection of the presence of a railway wheel and for applying the plurality of gage points on the gage circumference of the railway wheel sensed by the second sensor means to the wheel profile sensed by the first sensor means to generate an actual profile measurement of the railway wheel running surface and flange taken along a plane defined by a radial section of the railway wheel.

2. A measurement apparatus as claimed in claim 1 wherein the control means utilizes the sensed plurality of gage points to determine the center, diameter and angle of attack of the railway wheel.

3. A measurement apparatus as claimed in claim 1 wherein the second sensor means senses the end points of two chords of the gage circumference of the railway wheel.

4. A measurement apparatus as claimed in claim 3 wherein the two chords of the gage circumference of the railway wheel are substantially parallel with respect to one another.

5. A measurement apparatus as claimed in claim 4 wherein the control means determines a railway wheel angle of attack as a function of differences in height of the two end points of at least one of the chords of the gage circumference of the railway wheel with respect to a selected reference height.

6. A measurement apparatus as claimed in claim 1 wherein the profile is comprised of a plurality of spaced apart sensed points extending from the field side of the running surface to the gage side of the flange, the sensed points being more closely spaced proximate the flange as compared to the points that are proximate the rim of the railway wheel.

7. A measurement apparatus as claimed in claim 6 wherein the profile of the wheel is determined in world coordinates and corrected to wheel coordinates by the control means utilizing corrections derived from a plurality of gage points sensed by the second sensor means on the gage circumference of the railway wheel.

8. A measurement apparatus as claimed in claim 7 wherein the control means selects a tape line point, a flange height point and a flange thickness point from the plurality of points sensed by the first sensor means to define parameters of a rim thickness, a flange height and a flange thickness of the railway wheel, said parameters being representative of the railway wheel profile.

9. A measurement apparatus as claimed in claim 1 wherein the sensed profile of the railway wheel is corrected for motion for the railway wheel occurring in the period of time between sensing the presence of the railway wheel and the second sensor means sensing the railway wheel profile, the corrections for motion being a component of the actual profile measurement of the railway wheel.

10. A measurement apparatus as claimed in claim 1 wherein the sensed profile of the railway wheel is corrected for the diameter of the railway wheel.

11. A measurement apparatus as claimed in claim 1 wherein the first sensor means emitter is a light source and the receiver a light receiver.

12. A measurement apparatus as claimed in claim 11 wherein the first sensor means light source is a laser and the first sensor means light receiver is a camera.

13. A measurement apparatus as claimed in claim 11 wherein the light source projects light along a light path emanating from the light source and the light receiver detects light images along a light receiver axis, the light source light path and the light receiver axis lying in a common substantially vertical plane.

14. A measurement apparatus as claimed in claim 13 wherein the plane in which the light source light path and the light receiver axis lie is disposed at an acute included angle with respect to a substantially vertical plane that passes through the centerline of the rail.

15. A measurement apparatus as claimed in claim 14 wherein the included acute angle defined between the plane in which the light source light path and the light receiver axis lie and the substantially vertical plane that passes through the centerline of the rail is fifty-five degrees or less.

16. A measurement apparatus as claimed in claim 1 wherein the second sensor means emitter comprises a first light source and a second light source and the second sensor means receiver comprises a first light receiver and a second light receiver, the first light receiver being associated with the first light source and the second light receiver being associated with the second light source.

17. A measurement apparatus as claimed in claim 16 wherein the two sensor means light sources are lasers and the two sensor means light receivers are cameras.

18. A measurement apparatus as claimed in claim 16 wherein each of the two light sources projects light along a light path emanating from the respective light source and the associated light receiver detects light images along a light receiver axis, each light source light path and the associated light receiver axis lying in a common substantially vertical plane.

19. A measurement apparatus as claimed in claim 18 wherein the plane in which the first light source light path and the associated light receiver axis lie is spaced apart from and substantially parallel to the plane in which the second light source light path and the associated light receiver axis lie.

20. A measurement apparatus as claimed in claim 19 wherein the plane in which the first light source light path and the associated light receiver axis lie and the plane in which the second light source light path and the associated light receiver axis lie are disposed in a substantially orthogonal relationship with respect to a substantially vertical plane that passes through the centerline of the rail.

21. Measurement apparatus for measuring the profile of a railway wheel while said railway wheel is in rolling motion on a rail, said railway wheel having a gage side and a field side and a circumferentially defined running surface and flange, comprising:

first sensor means having an emitter and an associated receiver being disposed on the field side of the railway wheel and being disposed at an included angle with respect to the rail that is less than orthogonal for sensing the profile of the running surface and flange of the railway wheel at a point on circumference thereof;

second sensor means having at least one emitter and at least an associated receiver being disposed on the gage side of the railway wheel for sensing selected wheel parameters; and

a control means operably communicatively coupled to the first and second means for activating the first sensor means responsive to the detection of the presence of a railway wheel and for applying the selected railway wheel parameters sensed by the second sensor means to the wheel profile sensed by the first sensor means to generate an actual profile measurement of the railway wheel running surface and flange taken along a plane defined by a radial section of the railway wheel, wherein the sensed profile of the railway wheel is corrected for angle attack of the railway wheel existing at the time that the second sensor means senses the railway wheel profile, the correction for angle of attack being a component of the actual profile measurement of the railway wheel.

22. A method for measuring the profile of a railway wheel while said railway wheel is in rolling motion on a rail, said railway wheel having a gage side and a field side, a gage circumference being defined on the gage side thereof and having a rim having a circumferentially defined running surface and flange, comprising the steps of:

a. capturing the images including a first two gage points, a second two gage points, and the sensed profile of the running surface and flange substantially simultaneously;

b. determining the coordinates of end points of the sensed profile image;

c. determining the coordinates of the first two gage points;

d. determining the coordinates of the second two gage points;

e. calculating the wheel center, radius of the gage circumference, and wheel angle of attack in world coordinates using the coordinates of the first and second two gage points;

f. calculating the profile measurement comprised of a plurality of data points in world coordinates using the sensed profile image;

h. transforming all calculations into wheel coordinates from world coordinates using the wheel center as the origin of the wheel coordinates;

i. calculating the actual wheel profile comprising a plurality of data points, the wheel diameter, the angle of attack, the flange height, the flange thickness, and the rim thickness in wheel coordinates; and

j. reporting and saving the calculated data.

23. A method for measuring the profile of a railway wheel as claimed in claim 22 the wheel coordinates calculated in step i having substantially orthogonally disposed X and Y axes, step i of the method further including the steps of:

a. calculating a tapeline point on the running surface of the wheel by searching through the plurality of data points comprising the profile of the running surface and flange to determine the point that has an X dimension that is equal to 2.875 inches from a point on the gage circumference;

b. calculating the gage arm pivot point, said gage arm pivot point having a dimension of 1.609 inches in the minus X direction with respect to the tape line point and a dimension of 1.912 inches in the Y direction with respect to the tape line point;

c. calculating a circle centered on the gage arm pivot having a radius of 1.5 inches;

d. calculating the flange thickness by determining the flange thickness point, the flange thickness point being the point of intersection of said circle and the plurality of data points comprising the profile of the running surface and flange is the flange thickness point, the flange thickness being the dimension in the X direction from a point on the gage circumference to the flange thickness point; and

e. calculating the flange height by searching through the plurality of data points comprising the profile of the running surface and flange to determine that point that has the greatest Y dimension with respect to a point on the gage circumference, said point being the flange height point, the flange height being the dimension in the Y direction from the tape line point to the flange height point.

24. A method for measuring the profile of a railway wheel as claimed in claim 23, further including the step of:

a. calculating the railway wheel diameter at the tape line point, the diameter being equal to twice the radius of the gage circumference plus twice the rim thickness.

25. A method for measuring the profile of a railway wheel as claimed in claim 24, further including the step of:

a. calculating the speed of the railway wheel by dividing the distance between a first wheel presence sensor and a second wheel presence sensor by the time difference between detection of the railway wheel by first wheel presence sensor and by the second wheel presence sensor.

26. Measurement apparatus for measuring the profile of a railway wheel while said railway wheel is in rolling motion on a rail, said railway wheel having a gage side and a field side, a gage circumference being defined on the gage side thereof, and said railway wheel having a circumferentially defined running surface and flange, comprising:

first sensor means having an emitter and an associated receiver being disposed on the field side of the railway wheel and being disposed at an included angle with respect to the rail that is less than orthogonal for sensing the profile of the running surface and flange of the railway wheel at a point on circumference thereof;

second sensor means having at least one emitter and at least an associated receiver being disposed on the gage side of the railway wheel for sensing a plurality of gage points on the gage circumference of the railway wheel, said gage points being the end points of two chords of the gage circumference of the railway wheel, the two chords of the gage circumference of the railway wheel being substantially parallel with respect to one another; and

a control means operably communicatively coupled to the first and second means for activating the first sensor means responsive to the detection of the presence of a railway wheel and for applying the plurality of gage points on the gage circumference of the railway wheel sensed by the second sensor means to the wheel profile sensed by the first sensor means to generate an actual profile measurement of the railway wheel running surface and flange taken along a plane defined by a radial section of the railway wheel, wherein the control means determines a railway wheel angle of attack as a function of differences in height of the two end points of at least one of the chords of the gage circumference of the railway wheel with respect to a selected reference height.