Methods and systems for wheel profile measurement

• US 8,111,387 B2
• Filed: 05/08/2009
• Issued: 02/07/2012
• Est. Priority Date: 05/08/2008
• Status: Active Grant

• Current Assignee: Hunter Engineering Company
• Original Assignee: Hunter Engineering Company
• Inventors: Douglas, Michael W., Burns, Leigh R. Jr.
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): Bedard, Antoine J
• Application Number:
  US12/463,150
• Publication Number:
  US 20090279077A1
• Time in Patent Office: 1,005 Days
• Field of Search: 356/139.09
• US Class Current: 356/139.09
• 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 11/2755 using photoelectric detection means
• CPC Class Codes: G01B 2210/14 One or more cameras or other optical devices capable of acquiring a two-dimensional image

Abstract

Methods and systems for determining a parameter of a vehicle wheel are provided. The vehicle wheel is mounted on a shaft having an axis of rotation. The method includes projecting a pattern onto the wheel wherein the pattern includes a plurality of discrete optically detectable elements and determining a dimensional parameter of the wheel utilizing at least two of the plurality of discrete elements.

Claims

1. A method of determining a profile of a rim surface of a vehicle wheel, the vehicle wheel mounted on a shaft having an axis of rotation, the shaft provided on a vehicle service system configured as a wheel balancer or a tire changer, the vehicle service system further having a light source and an image sensor each fixedly mounted in predetermined positions relative to the vehicle service system, said method comprising:

projecting a pattern of light onto the rim surface of the wheel with the light source, the pattern of light including a plurality of discrete optically detectable elements;

obtaining at least one image of the plurality of discrete optically detectable elements with the image sensor; and

determining the profile of the rim surface of the vehicle wheel utilizing at least two of the plurality of discrete optically detectable elements in the at least one image.

2. A method in accordance with claim 1 wherein determining the profile of the wheel comprises:

determining a dimensional parameter of the wheel at a plurality of positions of selectable ones of the plurality of discrete optically detectable elements; and

determining the profile of the wheel using dimensional parameters determined at the plurality of positions.

3. A method in accordance with claim 2 further comprising determining wheel servicing characteristics of the wheel using the determined profile.

4. A method in accordance with claim 1 wherein projecting a pattern of light comprises directing a beam of laser light through a diffractive optical element (DOE).

5. A method in accordance with claim 1 wherein projecting a pattern of light comprises projecting a pattern onto the wheel using coded-spaced ray fan angles.

6. A method in accordance with claim 1 wherein determining the profile comprises determining a position of at least two optically detectable elements utilizing a predetermined spatial relationship between the image sensor and the light source.

7. A method in accordance with claim 1 wherein determining the profile comprises determining an angular relationship between at least one of the plurality of discrete optically detectable elements and at least one of the image sensor and the light source.

21. A method in accordance with claim 1, wherein the rim surface is an inner rim surface.

8. A wheel dimensional parameter measurement apparatus for a vehicle wheel service system, the vehicle wheel service system configured as a wheel balancer or a tire changer having a spindle shaft for rotatably mounting a vehicle wheel assembly including a wheel rim having a surface, said apparatus comprising:

a source of optical energy configured to direct a pattern of a plurality of discrete optically detectable elements onto the surface of the wheel rim, the source of optical energy mounted in a first fixed position relative to the surface of the wheel rim when the vehicle rim is mounted on the spindle shaft;

an imaging sensor fixedly positioned a known distance and orientation from said source of optical energy, said imaging sensor configured to acquire an image of at least two of the plurality of discrete optically detectable elements; and

a processor configured to;

determine a positional relationship between said imaging sensor and at least two of the plurality of discrete optically detectable elements from the acquired image; and

determine a profile of the surface of the wheel rim using the known distance and the determined positional relationship.

9. An apparatus in accordance with claim 8 wherein each discrete optically detectable element in the pattern is selected from the group of:

an alphanumeric element, a shape, an indicia, a dot, a line segment, a symbol, a geometric shape, an icon, images, and equivalents and combinations thereof.

10. An apparatus in accordance with claim 8 wherein the source of optical energy is configured to direct a pattern of a plurality of discrete optically detectable elements in a plurality of different wavelengths.

11. An apparatus in accordance with claim 8 wherein said source of optical energy comprises a laser light source and a diffractive optical element (DOE).

12. An apparatus in accordance with claim 8 wherein said pattern of discrete optically detectable elements comprises a first pattern and a second pattern spaced from one another.

13. An apparatus in accordance with claim 8 wherein said source of optical energy is directed through a slit aperture array.

14. An apparatus in accordance with claim 8 wherein said source of optical energy is configured to direct a pattern of a plurality of discrete optically detectable elements onto the wheel rim using coded-spaced ray fan angles.

22. An apparatus in accordance with claim 8, wherein the surface of the wheel rim is an inner rim surface.

15. A wheel service system comprising:

a spindle shaft configured to rotatably mount a vehicle wheel assembly thereon, the vehicle wheel assembly including a vehicle wheel rim having a surface;

at least one source of optical energy mounted stationary in a predetermined position relative to the spindle assembly and configured to project a plurality of discrete optically detectable elements onto the surface of the wheel rim in a predetermined pattern;

an imaging sensor fixedly positioned at a predetermined distance and orientation from said source of optical energy, said imaging sensor configured to acquire an image of at least two of the plurality of discrete optically detectable elements; and

a processor configured to;

determine a positional relationship between said imaging sensor and at least two of the plurality of discrete optically detectable elements using the acquired image and geometric parameters of the predetermined pattern;

determine a wheel identifier using the known distance and the determined positional relationship, wherein the wheel identifier is a wheel type, a model number, or other means that uniquely identifies the wheel such that wheel servicing characteristics may be determined; and

determine a profile of the surface of the wheel rim using the determined wheel identifier;

wherein the wheel service system is configured as a wheel balancer or a tire changer.

16. A system in accordance with claim 15 wherein said imaging sensor, said source of optical energy, and at least one of the plurality of discrete optically detectable elements define a triangle, and wherein said processor is configured to utilize a value of two of the angles of the triangle and the length of a common side between the two angles using the known distance and the determined positional relationship.

17. A system in accordance with claim 15 wherein said at least one source of optical energy is configured to project a plurality of patterns onto the surface of the wheel rim.

18. A system in accordance with claim 15 wherein said imaging sensor is configured to acquire a single image including the plurality of patterns.

19. A system in accordance with claim 15 further comprising a diffractive optical element (DOE) cooperating with the source of optical energy to project said plurality of discrete optically detectable elements onto the surface.

20. A system in accordance with claim 15 further comprising a slit aperture array cooperating with the source of optical energy to project said plurality of discrete optically detectable elements onto the surface.

23. A system in accordance with claim 15, wherein the surface of the wheel rim is an inner rim surface.

24. A service system for a vehicle wheel assembly including a vehicle wheel rim having an inner surface and an outer surface, the service system comprising:

a spindle shaft configured to rotatably mount the vehicle wheel assembly thereon;

at least one source of optical energy configured to project at least one linear pattern of light including a plurality of discrete optically detectable elements on the inner surface or the outer surface of the wheel rim;

an imaging sensor configured to acquire an image of the plurality of discrete optically detectable elements; and

a processor configured to;

determine a positional relationship between said imaging sensor and at least two of the plurality of discrete optically detectable elements using the acquired image; and

determine a profile of the inner surface or the outer surface of the wheel rim based on the determined positional relationship.

25. A system in accordance with claim 24, wherein the service system is configured as a wheel balancer or a tire changer.

26. A system in accordance with claim 24, wherein the linear pattern of light is non-movable relative to the inner surface.

27. A system in accordance with claim 24, wherein the plurality of discrete optically detectable elements comprise a plurality of dots.

28. A system in accordance with claim 24, wherein the imager is a two dimensional imager.