Method and system for determining the roundness of a golf ball
A golf ball is illuminated with diffused back lighting. CCD images of the golf ball are taken while the golf ball is being illuminated with the diffused back lighting. The edge or circumference of the golf ball is captured and sharply defined in the CCD images. The uniformity of the circumference may be determined by evaluating the radius of the object's circumference in an image, where an image is generated for n points around the circumference of the object, such as every 20° or 30°. By rotating the game ball, preferable with a battery operated stepper motor, the surface of the golf ball can be mapped.
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The present invention claims priority to provisional Patent Application No. 60/654,000 filed Feb. 18, 2005, the entirety of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to a method, a system and a computer program product for determining properties of a golf ball. More particularly, the present invention relates to a method, a device and a computer program product for determining properties of a golf ball as a function of orientation using a hand-held portable device.
2. Description of the Prior Art
Golf balls used by ordinary golfers vary in perfection. Imperfections may occur in golf ball manufacture that are not detected. More often, imperfections are introduced to a golf ball during usage of a golf ball. The imperfections that a golf ball is manufactured with and the imperfections introduced during usage of a golf ball affect the golf ball's flight on long drives or the golf ball's roll or direction when putted on a green. As a consequence of golf ball imperfections, the quality of a golfer's game may be reduced by factors not within his or her control. The enjoyment of the game as a challenge of skill is thus adversely affected.
Techniques have been developed to monitor golf ball quality in order to identify imperfections so that they do not have an impact on a game of golf. Techniques developed to determine the spherical shape of a golf ball implement gauges, various types of rings, and tubes which may be used. More recently, machine vision techniques have been described for determining the orientation of golf balls. These techniques print logos with respect to golf ball orientation and automation of this printing greatly improves golf ball manufacturing. This is important as golfers rely on the consistent placement of the logo to orient a ball for play. Other techniques inspect the repeated patterns, such as dimples, found on golf balls or the game ball to locate the position for printing a logo. The use of special lighting for obtaining CCD images of spherical objects, such as golf balls, has been implemented for visual or camera assisted evaluation of the golf ball patterns. However, the technologies currently available rely on visual interpretation of differences between a reference and the game ball. In addition, the technologies currently available focus on one kind of potential defect.
Accordingly, there is a need for a device to monitor the differences in properties between golf balls. There is a need for the device to be lightweight, and hand-held. There is a further need for the device to employ CCD images to assist a golfer in determining the properties of a golf ball. There is a further need for the device to determine a variety of properties of a golf ball. There is a further need for the device to determine the properties of a golf ball that directly affect putting. There is a further need for the device to determine a golf ball's out-of-roundness, size variations (oversized or undersized), balance, and blemishes on the golf ball surface. Also important is the golf ball's elastic properties that influence the length of drives.
SUMMARY OF THE INVENTIONAccording to embodiments of the present invention, a method, a device and a computer program product for determining properties of a golf ball as a function of orientation using a hand-held portable device are provided. The method illuminates a golf ball with diffused back lighting. CCD images of the golf ball are taken while the golf ball is being illuminated with the diffused back lighting. The edge or circumference of the golf ball is captured and sharply defined in the CCD images. The uniformity of the circumference may be determined by evaluating the radius of the circumference at n points around the circumference, such as every 20° or 30°. The evaluation of the radius is well known, for example as described in the publication Machine Vision, by E. R. Davies, which is hereby incorporated by reference in its entirety. By rotating the game ball, preferable with a battery operated stepper motor, the surface of the golf ball can be mapped. The generation of the CCD images, from an imaging system, such as the Scout™, may be triggered by the position of the stepper motor so as to have a correlation between image and ball position. The use of the logo as a reference point is of value in this regard.
In an embodiment of the invention, the uniformity of the circumference may be determined by the imaging system.
In an embodiment of the present invention, the uniformity of the circumference may be determined by a system separate from the imaging device.
BRIEF DESCRIPTION OF THE DRAWINGSThe above described features and advantages of the present invention will be more fully appreciated with reference to the detailed description and appended figures in which:
The present invention is now described more fully hereinafter with reference to the accompanying drawings that show embodiments of the present invention. The present invention, however, may be embodied in many different forms and should not be construed as limited to embodiments set forth herein. Appropriately, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention.
According to embodiments of the present invention, a method, a device and a computer program product for determining properties of a golf ball as a function of orientation using a hand-held portable device are provided. The method illuminates a golf ball with diffused back lighting. CCD images of the golf ball are taken while the golf ball is being illuminated with the diffused back lighting. The edge or circumference of the golf ball is captured and sharply defined in the CCD images. The uniformity of the circumference may be determined by evaluating the radius of the object's circumference in an image, where an image is generated for n points around the circumference of the object, such as every 20° or 30°. The evaluation of the radius is well known, for example as described in the publication Machine Vision, by E. R. Davies, which is hereby incorporated by reference in its entirety. By rotating the game ball, preferable with a battery operated stepper motor, the surface of the golf ball can be mapped. The generation of the CCD images, from a imaging system, such as the Scout™, may be triggered by the position of the stepper motor so as to have a correlation between image and ball position. The use of the logo as a reference point is of value in this regard.
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The Door E (314) allows for the object to be inserted into monitoring system 104 and includes a shaft 316 that centers the golf ball into the concave surface of the stage to allow for wobble-free rotation of the golf ball. In an embodiment of the present invention, the shaft 316 is made from an appropriate plastic, such as nylon, so that the golf ball is supported, but not damaged during inspection. In an embodiment of the present invention, the end of this shaft 316 is concave to better support the golf ball. The monitoring system housing houses the components of monitoring system 104 and couples to a camera, such as imaging circuitry 106 having a lens with a short focal length appropriate for imaging the golf ball. The shaft 316 may also be elongated and flexible such that on fast rotation by the stepper motor, the balance of the golf ball may be determined. If the center of gravity is the center of the sphere for the golf ball, the ball will rotate without wobble. If the center of gravity is not at the center of the golf ball, the ball will rotate with a wobble, where the maximum excursion of the wobble is the direction of the center of gravity, the balance point. Several approaches may be used to determine the balance point, e.g., by use of the Scout™ imaging system whose image will identify wobble and by use of a marking system (not shown) where a ink mark is placed on the ball during rotation at the maximum of the wobble. The ink mark identifies the direction of the balance point such that a golfer can properly place the ball for putting.
The camera records the image of the golf ball and provides this data for evaluation of the edge properties. The camera also contains the electronics to select the number of images for evaluating the golf ball. Each image requires the stepper motor to change the orientation of the golf ball. The camera provides a range of options in selecting the number of images and therefore orientations for evaluation of the golf ball. In an embodiment of the present invention, 6 through 12 images may be used corresponding to 60° or 30° inspection angles. In an embodiment of the present invention, the data are evaluated by the processor of system 100. In embodiment of the present invention, the data is transferred to a processor and software operable to perform the evaluations of the present invention.
While specific embodiments of the present invention have been illustrated and described, it will be understood by those having ordinary skill in the art that changes can be made to those embodiments without departing from the spirit and scope of the invention. For example, while the present invention concentrates on a single color digital image and stationary lost object analysis, it is understood that information from a series of images, a moving object or a specific object might advantageously be used as well. Also, while our application to golf balls has options for using UV and visible light, the method is not dependent on this choice.
Claims
1. A method of determining the properties of an object as a function of the object's orientation, the method comprising:
- providing the object to be evaluated;
- generating a digital image of the object with diffused back lighting at a plurality of different orientations;
- evaluating the radius of the object in each of the digital images of the object with diffused back lighting;
- determining a first property of the object, wherein the first property of the object is the uniformity of the object's circumference based on the evaluation of the radius of the object in each of the digital images.
2. The method according to claim 1, further comprising illuminating a light source prior to generating each digital image.
3. The method according to claim 2, further comprising transmitting light from the light source through a diffused screen.
4. The method according to claim 1, further comprising rotating a stepper motor prior to generating each digital image.
5. The method according to claim 1, further comprising storing data pertaining to the radius of the object in each digital image.
6. The method according to claim 1, further comprising reporting the object's first property.
7. The method according to claim 1, further comprising applying force to the object and measuring the return force of the object to determine a second property of the object, wherein the second property is the elasticity of the object.
8. An apparatus for determining the properties of an object as a function of the object's orientation comprising:
- a processor operable to execute computer program instructions; and
- a memory operable to store computer program instructions executable by the processor, for performing the steps of:
- generating a digital image of the object with diffused back lighting at a plurality of different orientations;
- evaluating the radius of the object in each of the digital images of the object with diffused back lighting;
- determining a first property of the object, wherein the first property of the object is the uniformity of the object's circumference based on the evaluation of the radius of the object in each of the digital images.
9. The apparatus according to claim 8, further comprising computer program instructions executable by the processor, for performing the step of illuminating a light source prior to generating each digital image.
10. The apparatus according to claim 9, further comprising computer program instructions executable by the processor, for performing the step of transmitting light from the light source through a diffused screen.
11. The apparatus according to claim 8, further comprising computer program instructions executable by the processor, for performing the step of rotating a stepper motor prior to generating each digital image.
12. The apparatus according to claim 8, further comprising computer program instructions executable by the processor, for performing the step of storing data pertaining to the radius of the object in each digital image.
13. The apparatus according to claim 8, further comprising computer program instructions executable by the processor, for performing the step of reporting the object's first property.
14. The apparatus according to claim 8, further comprising computer program instructions executable by the processor, for performing the steps of applying force to the object and measuring the return force of the object to determine a second property of the object, wherein the second property is the elasticity of the object.
Type: Application
Filed: Feb 21, 2006
Publication Date: Aug 24, 2006
Applicant:
Inventors: Peter Zanzucchi (Princeton Junction, NJ), Jonathan Bernstein (New York, NY)
Application Number: 11/357,217
International Classification: B41F 33/00 (20060101);