Method and apparatus for vehicle service system optical target assembly

1. A method for determining the alignment of a vehicle wheel, comprising the steps of:

attaching a single optical target with a dimensionally stable shape to the vehicle wheel, wherein the optical target has thereon a plurality of target elements arranged in a known geometric and spatial configuration relative to each other, and wherein said dimensionally stable shape is a three dimensional shape which includes at least one non-planar target surface or smoothly curved target surface upon which said plurality of target elements is arranged;

detecting, from a two-dimensional image of the single optical target acquired by an imaging system, a plurality of target element images corresponding to the plurality of target elements arranged on the non-planar or smoothly curved target surface of the optical target; and

determining the alignment of the vehicle wheel based on a spatial orientation of the optical target identified from the plurality of target element images and the known geometric and spatial configuration of the plurality of target elements on the non-planar or smoothly curved target surface of the optical target.

2. The method of claim 1 wherein the step of determining the alignment of the vehicle wheel comprises the step of detecting an image feature of at least one target element image.

3. A method for determining the alignment of a vehicle wheel, comprising the steps of:

securing a single optical target with a dimensionally stable shape to said vehicle wheel, said optical target having thereon a plurality of target elements arranged in a known geometric and spatial configuration relative to each other on at least two surfaces;

acquiring a two-dimensional image of the optical target using at least one imaging sensor;

utilizing the acquired image of the optical target to determine wheel alignment based on the optical target, said acquired two-dimensional image including images of at least one target element from each of said surfaces.

4. The method of claim 3 for determining the alignment of a vehicle wheel wherein said at least two surfaces are angled relative to each other.

5. The method of claim 3 for determining the alignment of a vehicle wheel

wherein said step of utilizing the acquired image of the optical target further utilizes said target element images to determine wheel alignment based on the optical target.

6. A system for determining the alignment of a vehicle wheel, comprising:

an optical target for attachment to a vehicle wheel, wherein the optical target has at least two surfaces with a plurality of target elements arranged thereon in geometric and spatial configurations relative to each other;

an imaging system for acquiring two-dimensional images of the optical target;

a target element feature detecting system for detecting, from said acquired images, a plurality of target element images corresponding to at least some of the plurality of target elements, including said at least one target element from said first surface, and said at least one target element from said second surface; and

a wheel alignment system processing unit for determining the alignment of the vehicle wheel based on a spatial orientation of the optical target determined in accordance with the detected target element images and the geometric and spatial configuration of the target elements on the optical target surfaces.

7. The system of claim 6 wherein said target elements are arranged in known geometric and spatial configurations relative to each other.

8. The system of claim 6 wherein said wheel alignment system processing unit is configured to determine the geometric and spatial configurations of the target elements on the optical target surfaces from said acquired images prior to determining the spatial orientation of the optical target.

9. The system of claim 6 wherein said imaging system includes a plurality of imaging sensors configured to acquire said images of the optical target.

10. A method for determining a measurement relating to an object, comprising the steps of:

associating an optical target with the object, wherein the optical target has at least two surfaces with a plurality of target elements arranged thereon in geometric and spatial configurations relative to each other;

detecting, from at least one two-dimensional image of the optical target acquired by at least one imaging sensor, a plurality of target element images corresponding to at least some of the plurality of target elements, including said at least one target element from said first surface, and said at least one target element from said second surface; and

determining the measurements relating to the object based on a spatial orientation of the optical target identified from the target element images and the geometric and spatial configuration of the target elements.

11. The method of claim 10 wherein said target elements are arranged in known geometric and spatial configurations relative to each other.

12. The method of claim 10 further including the step of determining the geometric and spatial configurations of the target elements on the optical target surfaces from said detected plurality of target element images prior to determining the measurements relating to the object.

13. The method of claim 12 wherein said plurality of target element images are detected from a plurality of two-dimensional images of the optical target acquired by at least one imaging sensor, said optical target images representative of at least two different rotational positions of the optical target.

14. An improved machine vision vehicle wheel alignment system having a processing unit and at least one imaging sensor for acquiring images, the improvement comprising:

a single non-planar target having a plurality of visible features, said non-planar target removably secured against a vehicle wheel assembly surface within a field of view of the imaging sensor;

wherein the processing unit is configured to receive data from the imaging sensor which is representative of said visible features of said single non-planar target; and

wherein the processing unit is configured to determine at least an axis of rotation of the vehicle wheel utilizing said received data.

15. The improved machine vision vehicle wheel alignment system of claim 14 wherein said data is representative of said visible features in at least two different rotational positions about said axis of rotation of the vehicle wheel.

16. The improved machine vision vehicle wheel alignment system of claim 14 wherein the processing unit is configured to identify an intersection point between said axis of rotation of the vehicle wheel and said non-planar target.

17. The improved machine vision vehicle wheel alignment system of claim 14 wherein said visible features of said single non-planar target are disposed on a plurality of angled surfaces.

18. An improved machine vision vehicle wheel alignment system having a processing unit and at least one imaging sensor for acquiring images, the improvement comprising:

a non-planar target having a plurality of visible features, said non-planar target removably secured against a vehicle wheel assembly surface within a field of view of the imaging sensor;

wherein said visible features of said non-planar target are disposed on at least one curved surface;

wherein the processing unit is configured to receive data from the imaging sensor which is representative of said visible features; and

wherein the processing unit is configured to determine at least an axis of rotation of the vehicle wheel utilizing said received data.