Method and apparatus for measuring ball launch conditions

• US 8,016,688 B2
• Filed: 08/15/2005
• Issued: 09/13/2011
• Est. Priority Date: 08/15/2005
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Gobush, William
• Primary Examiner(s): Vo; Peter DungBa
• Assistant Examiner(s): WONG, JEFFREY KEITH
• Application Number:
  US11/203,149
• Publication Number:
  US 20070060410A1
• Time in Patent Office: 2,220 Days
• Field of Search: 463/2, 463/3, 473/140, 473/131, 473/200, 473/151, 473/199, 473/198
• US Class Current: 473/131
• CPC Class Codes: A63B 2024/0031 at the starting point
• CPC Class Codes: A63B 2220/35 Spin
• CPC Class Codes: A63B 24/0021 Tracking a path or terminating locations
• CPC Class Codes: A63B 69/3614 using electro-magnetic, magnetic or ultrasonic radiation emitted, reflected or interrupted by the golf club
• CPC Class Codes: A63B 69/3658 Means associated with the ball for indicating or measuring, e.g. speed, direction

Abstract

A method and apparatus for measuring ball launch conditions is disclosed. Specifically, the accuracy of the calculations used to determine the kinematic characteristics may be increased. A background image of a field of view, without a golf ball present, may be acquired. Two or more images of a golf ball in motion are then be acquired based on positive or negative imaging. The background image is subtracted from each of the two or more images of the golf ball. After subtracting the background image, the two or more images of the golf ball are analyzed to determine the location of the circular perimeter of the golf ball. Based on the location of the circular perimeter of the golf ball, the location of the center of the golf ball may be calculated. Knowing the location of the center of the golf ball increases the accuracy of measurements of kinematic characteristics such as sidespin, backspin, velocity, and launch angle.

Claims

1. An apparatus for determining the kinematics of an object, comprising:

a camera positioned to acquire one or more images of a field of view, the camera including a filter;

an illumination device selectively positioned to illuminate a field of view using light within a predetermined wavelength range;

a golf ball having a surface that responds to the light to generate a camera image; and

a background surface that absorbs the light within the predetermined wavelength range wherein an image of the background surface is subtracted from an image of the golf ball and used to determine a center of the golf ball.

2. The apparatus according to claim 1, further comprising a processor comprising memory and analyzing software loaded thereon, wherein the software is operable to analyze the one or more acquired images to determine a position of a center of a golf ball.

3. The apparatus according to claim 2, wherein the camera comprises a CCD having at least about a four megapixel resolution or greater.

4. The apparatus according to claim 1 , wherein the golf ball includes one or more substantially circular markers that absorb light and have a low grey level surface.

5. The apparatus according to claim 1, wherein the background surface comprises a low grey level surface.

6. The apparatus according to claim 1, wherein the background surface emits a limited spectrum of light.

7. The apparatus according to claim 1, wherein the illumination device includes a filter.

8. The apparatus according to claim 1, wherein the illumination device comprises a strobe lamp.

9. A method for determining the kinematics of a golf object, comprising:

acquiring an image of a field of view without a golf ball present;

acquiring at least two images of a golf ball in motion within the field of view, wherein the golf ball comprises one or more substantially circular markers;

subtracting the image of the field of view from each of the at least two images of the golf ball in motion; and

determining the location of a circular perimeter of the golf ball for each of the at least two images after the image of the field of view is subtracted;

wherein the subtracting and the determining are performed by a processor comprising a memory and software loaded thereon.

10. The method according to claim 9, further including analyzing the circular perimeter in each of the at least two images to determine a position of a center of the golf ball in each image.

11. The method according to claim 9, further comprising determining the kinematic characteristics of the golf ball based on the substantially circular markers and the center of the golf ball in each of the at least two images.

12. The method according to claim 11, wherein the kinematic characteristics comprise at least one of side spin, back spin, trajectory, velocity, launch angle, and side angle.

13. An apparatus for determining the kinematics of an object, comprising:

a camera positioned to acquire one or more images of a field of view;

an illumination device selectively positioned to illuminate the field of view using light within a predetermined wavelength range;

a golf ball having a surface that absorbs light within the predetermined wavelength range; and

a background surface that reflects the light within the predetermined wavelength range wherein an image of the background surface is subtracted from an image of the golf ball in order to determine a center of the golf ball;

wherein the subtracting and the determining are performed by a processor comprising a memory and software loaded thereon.

14. The apparatus according to claim 13, wherein the background surface comprises a high grey level surface.

15. The apparatus according to claim 13, wherein the illumination device comprises a strobe lamp.

16. The apparatus according to claim 13, wherein the camera includes a filter.

17. The apparatus according to claim 13, wherein the camera comprises about a 4 megapixel resolution or greater.

18. The apparatus according to claim 13, wherein the golf ball includes one or more substantially circular markers that comprise a high grey level surface.