U.S. patent application number 11/841170 was filed with the patent office on 2008-11-20 for system and method for measuring a golfer's ball striking parameters.
This patent application is currently assigned to CALLAWAY GOLF COMPANY. Invention is credited to SCOTT R. MANWARING.
Application Number | 20080287207 11/841170 |
Document ID | / |
Family ID | 40028059 |
Filed Date | 2008-11-20 |
United States Patent
Application |
20080287207 |
Kind Code |
A1 |
MANWARING; SCOTT R. |
November 20, 2008 |
SYSTEM AND METHOD FOR MEASURING A GOLFER'S BALL STRIKING
PARAMETERS
Abstract
A system (20) for capturing and analyzing golf club information
and golf ball information during and after a golfer's swing is
disclosed herein. The golf club information includes golf club head
orientation, golf club head velocity, and golf club spin. The golf
club head orientation includes dynamic lie, loft and face angle of
the golf club head. The golf club head velocity includes path of
the golf club head, attack of the golf club head and downrange
information. The golf ball information includes golf ball velocity,
golf ball launch angle, golf ball side angle, golf ball speed
manipulation and golf ball orientation. The golf ball orientation
includes the true spin of the golf ball, and the tilt axis of the
golf ball which entails the back spin and the side spin of the golf
ball. The system includes CMOS camera units (26 and 28) and a
computer (22).
Inventors: |
MANWARING; SCOTT R.;
(CARLSBAD, CA) |
Correspondence
Address: |
CALLAWAY GOLF C0MPANY
2180 RUTHERFORD ROAD
CARLSBAD
CA
92008-7328
US
|
Assignee: |
CALLAWAY GOLF COMPANY
CARLSBAD
CA
|
Family ID: |
40028059 |
Appl. No.: |
11/841170 |
Filed: |
August 20, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10843048 |
May 10, 2004 |
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11841170 |
|
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60498469 |
Aug 27, 2003 |
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Current U.S.
Class: |
473/199 ;
473/223; 473/233; 473/407; 473/409 |
Current CPC
Class: |
A63B 24/0003 20130101;
A63B 69/3614 20130101; A63B 24/0006 20130101; A63B 2024/0031
20130101; A63B 69/3623 20130101; A63B 24/0021 20130101; A63B
2024/0056 20130101; A63B 2024/0037 20130101; A63B 2220/806
20130101; A63B 2024/0028 20130101; A63B 2220/35 20130101; A63B
69/3658 20130101; A63B 2220/05 20130101; A63B 2220/30 20130101 |
Class at
Publication: |
473/199 ;
473/407; 473/223; 473/233; 473/409 |
International
Class: |
A63B 69/36 20060101
A63B069/36 |
Claims
1. A method for measuring a golfer's ball striking properties, the
method comprising: monitoring a field of view for detection of an
object, the object being a golf club or a golf ball; detecting the
object within the field view; creating a first region of interest
within the field of view, the region of interest encompassing the
object; tracking the movement of the object in the field of view
with a plurality of regions of interest; creating of a plurality of
images from each of the plurality of regions of interest; obtaining
a golfer's ball striking properties from the plurality of
images.
2. A method for measuring a golfer's ball striking properties using
a CMOS based imaging system, the method comprising: monitoring a
sensor array for detection of an object, the sensor array composed
of at least one million active pixels; detecting an object having a
threshold brightness within the sensor array; creating a first
region of interest within the field of view, the region of interest
encompassing the object; tracking the movement of the object in the
field of view with a plurality of regions of interest; creating of
a plurality of images from each of the plurality of regions of
interest; obtaining a golfer's ball striking properties from the
plurality of images.
3. A method for measuring a golfer's ball striking properties using
a CMOS based imaging system, the method comprising: generating an
image of a field of view at a frame rate of 250 to 500 frames per
second to monitor for detection of an object, the field of view
corresponding to a CMOS sensor array composed of at least one
million active pixels, the object being a golf club or golf ball;
detecting an object having a threshold brightness within the field
of view; creating a region of interest within the field of view,
the region of interest encompassing the object, the region of
interest corresponding to a plurality of active pixels of the CMOS
sensor array; tracking the object through the field of view with a
plurality of overlapping regions of interest that encompass the
object, each of the plurality of overlapping regions of interest
corresponding to a plurality of active pixels of the CMOS sensor
array; and analyzing the plurality of regions of interest to obtain
swing properties for the golf club or launch parameters for the
golf ball.
4. A method for measuring a golfer's ball striking properties using
a CMOS based imaging system, the method comprising: generating an
image of a field of view at a frame rate of 250 to 500 frames per
second to monitor for detection of an object, the field of view
corresponding to a CMOS sensor array composed of at least one
million active pixels, the object being a golf club or golf ball;
detecting an object having a threshold brightness within the field
of view; creating a region of interest within the field of view,
the region of interest encompassing the object, the region of
interest corresponding to a plurality of active pixels of the CMOS
sensor array; tracking the object through the field of view with a
plurality of overlapping regions of interest that encompass the
object, each of the plurality of overlapping regions of interest
corresponding to a plurality of active pixels of the CMOS sensor
array; and analyzing the plurality of regions of interest to obtain
swing properties for the golf club or launch parameters for the
golf ball.
5. A method for simultaneously measuring the golf club properties
and the golf ball properties during a golfer's striking of a golf
ball, the method comprising: swinging a golf club toward a teed
golf ball; activating an imaging system, the imaging system capable
of compiling a plurality of images; taking a first plurality of
images of the golf club head prior to the golf club head impacting
the teed golf ball; striking the teed golf ball with the golf club;
taking a second plurality of images of the golf ball after the golf
ball has been struck by the golf club head; wherein the method
provides measurements of the golf club head and of the launched
golf ball.
6. The method according to claim 1 wherein the imaging system
comprises a first CMOS camera and a second CMOS camera.
7. A system simultaneously measuring the golf club properties and
the golf ball properties during a golfer's striking of a golf ball,
the system comprising: a first CMOS camera and a second CMOS
camera, each of the first and second cameras focused toward a
predetermined field view; a golf club having at least one light
contrasting area thereon; a golf ball teed within the predetermined
field of view; and means for determining the golf club swing
properties and golf ball launch properties based on images
generated by the first and second CMOS cameras.
8. A method for using a CMOS imaging system to determine golf club
swing properties and golf ball launch properties.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The Present Application is a continuation of U.S. patent
application Ser. No. 10/843048, filed on May 10, 2004, which claims
priority to U.S. Provisional Application No. 60/498,469 filed on
Aug. 27, 2003, now abandoned.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a system and method for
measuring a golfer's swing parameters during a golf swing. More
specifically, the present invention relates to a system and method
for measuring club head information and golf ball information
before and after impact of the golf club with the golf ball.
[0005] 2. Description of the Related Art
[0006] For over twenty-five years, high speed camera technology has
been used for gathering information on a golfer's swing. The
information has varied from simple club head speed to the spin of
the golf ball after impact with a certain golf club. Over the
years, this information has fostered numerous improvements in golf
clubs and golf balls, and assisted golfers in choosing golf clubs
and golf balls that improve their game. Additionally, systems
incorporating such high speed camera technology have been used in
teaching golfers how to improve their swing when using a given golf
club.
[0007] An example of such a system is U.S. Pat. No. 4,063,259 to
Lynch et al., for a Method Of Matching Golfer With Golf Ball, Golf
Club, Or Style Of Play, which was filed in 1975. Lynch discloses a
system that provides golf ball launch measurements through use of a
shuttered camera that is activated when a club head breaks a beam
of light that activates the flashing of a light source to provide
stop action of the club head and golf ball on a camera film. The
golf ball launch measurements retrieved by the Lynch system include
initial velocity, initial spin velocity and launch angle.
[0008] Another example is U.S. Pat. No. 4,136,387 to Sullivan, et
al., for a Golf Club Impact And Golf Ball Launching Monitoring
System, which was filed in 1977. Sullivan discloses a system that
not only provides golf ball launch measurements, it also provides
measurements on the golf club.
[0009] Yet another example is a family of patent to Gobush et al.,
U.S. Pat. Nos. 5,471,383 filed on Sep. 30, 1994; 5,501,463 filed on
Feb. 24, 1994; 5,575,719 filed on Aug. 1, 1995; and 5,803,823 filed
on Nov. 18, 1996. This family of patents discloses a system that
has two cameras angled toward each other, a golf ball with
reflective markers, a golf club with reflective markers thereon and
a computer. The system allows for measurement of the golf club or
golf ball separately, based on the plotting of points.
[0010] Yet another example is U.S. Pat. No. 6,042,483 for a Method
Of Measuring Motion Of A Golf Ball. The patent discloses a system
that uses three cameras, an optical sensor means, and strobes to
obtain golf club and golf ball information.
[0011] Many current ball launch monitors utilize CCD (charge
coupled device) cameras to obtain images to analyze a golfer's
swing parameters. A CCD camera is limited to a set field of view,
and also has limitations as to the number of images that can be
obtained within a second.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention provides a method and system for
capturing and analyzing golf club information and golf ball
information during and after a golfer's swing is disclosed herein.
The golf club information includes golf club head orientation, golf
club head velocity, and golf club spin. The golf club head
orientation includes dynamic lie, loft and face angle of the golf
club head. The golf club head velocity includes path of the golf
club head and attack of the golf club head. The golf ball
information includes golf ball velocity, golf ball launch angle,
golf ball side angle, golf ball speed and golf ball orientation.
The golf ball orientation includes the true spin of the golf ball,
and the tilt axis of the golf ball which entails the back spin and
the side spin of the golf ball.
[0013] One aspect of the present invention is a system for
simultaneously measuring the golf club properties and the golf ball
properties during a golfer's striking of a golf ball. The system
includes a pair of CMOS cameras, a golf club, a golf ball, a
calculating means and an analysis means. The first and second CMOS
cameras each have a lens focused toward a predetermined field of
view. The golf club has at least one light contrasting area, and
preferably three light contrasting areas. The golf ball is within
the predetermined field of view. The analysis means determines the
golf club swing properties and golf ball launch properties based on
an images generated by the first and second CMOS cameras.
[0014] Having briefly described the present invention, the above
and further objects, features and advantages thereof will be
recognized by those skilled in the pertinent art from the following
detailed description of the invention when taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of the monitoring system of the
present invention.
[0016] FIG. 2 is a schematic isolated side view of the teed golf
ball and the cameras of the system of the present invention.
[0017] FIG. 2A is a schematic isolated side view of the teed golf
ball and the cameras of the system showing the field of view of the
cameras.
[0018] FIG. 3 is a schematic isolated front view of the teed golf
ball, trigger device and the cameras of the system of the present
invention.
[0019] FIG. 4 is a schematic representation of a full frame CMOS
sensor array.
[0020] FIG. 5 is a schematic representation of a field of view.
[0021] FIG. 6 a schematic representation of a ROI within the CMOS
sensor array.
[0022] FIG. 7 a schematic representation of an object within the
field of view.
[0023] FIG. 8 a schematic representation of an object within the
field of view.
[0024] FIG. 9 a schematic representation of a ROI within the CMOS
sensor array.
[0025] FIG. 10 a schematic representation of an object within the
field of view.
[0026] FIG. 11 a schematic representation of a ROI within the CMOS
sensor array.
[0027] FIG. 12 a schematic representation of an object within the
field of view.
[0028] FIG. 13 a schematic representation of a ROI within the CMOS
sensor array.
[0029] FIG. 14 is a flow chart of a method of using the system of
the invention.
[0030] FIG. 15 is a flow chart of a method of using the system of
the invention.
[0031] FIG. 16 is a flow chart of a method of using the system of
the invention.
[0032] FIG. 17 is a flow chart of a method of using the system of
the invention.
[0033] FIG. 18 is a flow chart of a method of using the system of
the invention.
[0034] FIG. 19 is a schematic representation of the highly
reflective points of the golf club positioned in accordance with
the first, second and third exposures of the golf club.
[0035] FIG. 20 is an isolated view of a golf ball striped for
measurement.
[0036] FIG. 20A is an isolated view of a golf ball striped for
measurement using an image with a partial phantom of a prior image
with vector signs present to demonstrate calculation of angle
.theta..
[0037] FIG. 21 illustrates first, second and third images of the
connected highly reflective points on a golf club, and the teed
golf ball for the first find grouping of the highly reflective
points.
[0038] FIG. 21A illustrates first, second and third images of the
connected highly reflective points on a golf club, and the teed
golf ball for the first find grouping of the highly reflective
points.
[0039] FIG. 22 illustrates first, second and third images of the
connected highly reflective points on a golf club, and the teed
golf ball for the second find grouping of the highly reflective
points.
[0040] FIG. 23 illustrates first, second and third images of the
connected highly reflective points on a golf club, and the teed
golf ball for the second find grouping of the highly reflective
points.
[0041] FIG. 24 illustrates first, second and third images of the
connected highly reflective points on a golf club, and the teed
golf ball with repeated points eliminated and results of the find
displayed.
[0042] FIG. 25 illustrates first, second and third images of the
connected highly reflective points on a golf club, and the teed
golf ball with repeated points eliminated and results of the find
displayed.
[0043] FIG. 26 is a chart of the processed final pairs giving the
x, y and z coordinates.
[0044] FIG. 27 is an illustration of the images for the golf ball
in flight.
[0045] FIG. 28 is an isolated view of the golf ball to illustrate
determining the best ball center and radius.
[0046] FIG. 29 is a partial flow chart with images of golf balls
for stereo correlating two dimensional points.
[0047] FIG. 30 illustrates the teed golf ball and the first,
second, third and fourth images of the golf ball after impact,
along with positioning information.
DETAILED DESCRIPTION OF THE INVENTION
[0048] As shown in FIGS. 1-3, the system of the present invention
is generally designated 20. The system 20 captures and analyzes
golf club information and golf ball information during and after a
golfer's swing. The golf club information includes golf club head
orientation, golf club head velocity, and golf club spin. The golf
club head orientation includes dynamic lie, loft and face angle of
the golf club head. The golf club head velocity includes path of
the golf club head and attack of the golf club head. The golf ball
information includes golf ball velocity, golf ball launch angle,
golf ball side angle, golf ball speed and golf ball orientation.
The golf ball orientation includes the true spin of the golf ball,
and the tilt axis of the golf ball which entails the back spin and
the side spin of the golf ball. The various measurements will be
described in greater detail below.
[0049] The system 20 generally includes a computer 22, a camera
structure 24 with a first camera unit 26, a second camera unit 28
and an optional trigger device 30, a golf ball 32 and a golf club
33. The system 20 is designed to operate on-course, at a driving
range, inside a retail store/showroom, or at similar
facilities.
[0050] In a preferred embodiment, the camera structure 24 is
connected to a frame 34 that has a first platform 36 approximately
46.5 inches from the ground, and a second platform 38 approximately
28.5 inches from the ground. The first camera unit 26 is disposed
on the first platform 36 and the second camera unit 28 is disposed
on the second platform 38. As shown in FIG. 2, the first platform
36 is at an angle al which is approximately 41.3 degrees relative
to a line perpendicular to the straight frame vertical bar of the
frame 34, and the second platform 38 is at an angle {acute over
(.alpha.)}.sub.2 which is approximately 25.3 degrees relative to a
line perpendicular to the straight frame vertical bar of the frame
34. However, those skilled in the relevant art will recognize that
other angles may be utilized for the positioning of the cameras
without departing from the scope and spirit of the present
invention.
[0051] As shown in FIG. 2A, the platforms 36 and 38 are preferably
positioned such that the optical axis 66 of the first camera unit
26 does not overlap/intersect the optical axis 68 of the second
camera unit 28. The optical view of the first camera unit 26 is
preferably bound by lines 62a and 62b, while the optical view of
the second camera unit 28 is bound by lines 64a and 64b. The
overlap area defined by curves 70 is the field of view of the
system 20.
[0052] The first camera unit 26 preferably includes a first camera
40 and optional flash units 42a and 42b. The second camera unit 28
preferably includes a second camera 44 and optional flash units 46a
and 46b. A preferred camera is a complementary metal oxide
semiconductor ("CMOS") camera with active pixel technology and a
fall frame rate ranging from 250 to 500 frames per second.
[0053] The optional trigger device 30 includes a receiver 48 and a
transmitter 50. The transmitter 50 is preferably mounted on the
frame 34 a predetermined distance from the camera units 26 and 28.
The golf ball is preferably placed on a tee 58. The golf ball 32 is
a predetermined length from the frame 34, L.sub.1, and this length
is preferably 38.5 inches. However, those skilled in the pertinent
art will recognize that the length may vary depending on the
location and the placement of the first and second camera units 26
and 28. The transmitter 50 is preferably disposed from 10 inches to
14 inches from the cameras 40 and 44.
[0054] The data is collected by the cameras and preferably sent to
the computer 22 via a cable 52 which is connected to the receiver
48 and the first and second camera units 26 and 28. The computer 22
has a monitor 54 for displaying images generated by the first and
second camera units 26 and 28.
[0055] The field of view 100 of the cameras 40 and 44 corresponds
to the CMOS sensor array 200. In a preferred embodiment, the CMOS
sensor array 200 is at least one megapixel in size having one
thousand rows of pixels and one thousand columns of pixels for a
total of one million pixels. As shown in FIG. 4, a CMOS sensor
array 200 preferably has one million active pixels 205. Each active
pixel 205 is capable of acting as a single camera to provide an
image or a portion of an image. As shown in FIG. 5, the field of
view 100 corresponds to the fall frame of the CMOS sensor array
200, which preferably operates at a minimum frame rate ranging from
250 to 500 frames per second, however, it may have a frame rate as
low as 30 frames per second. At this frame rate, the CMOS sensor
array 200 is monitoring the field of view at a rate of 250-500
times per second and is capable of creating images at 250 to 500
times per second. The CMOS sensor array 200 preferably has one
thousand columns of active pixels 205 and one thousand rows of
active pixels 205. In a preferred embodiment, the field of view 100
is large enough to capture pre-impact golf club information and
post-impact golf ball information. However, those skilled in the
pertinent art will recognize that the field of view 100 may be
adjusted to focus on any particular action by the golfer such as
only pre-impact information, putting information, and the like.
[0056] As shown in FIG. 6, an initial region of interest ("ROI")
210 is established at the edge 150 of the field of view 100 or CMOS
sensor array 200. In a preferred embodiment, the initial ROI 210
extends along all of the rows of the sensor array 200 and from 10
to 100 columns of the CMOS sensor array 200 beginning with the
first column of active pixels 205 at the edge 150. In establishing
an ROI, only those pixels within the ROI are activated while the
pixels outside of the ROI are deactivated. Reducing the number of
active pixels 205 increases the frame rate in a pseudo-inverse
relationship. Thus, if only 25% of the active pixels of the CMOS
sensor array are activated, and the full frame rate of the CMOS
sensor array 200 is 500 frames per second. Then, the frame rate of
the ROI is 2000 frames per second. Thus, reducing the number of
active pixels 205 allows for the increased monitoring of a ROI
thereby providing increased information about an object entering
the ROI since an increased number of images may be obtained of the
object within the ROI.
[0057] The establishment of an ROI 210 at the edge 150 allows for
"through the lens" triggering of the system 20. The through the
lens triggering is a substitute for the triggering device 30. The
system 20 is monitoring the ROI 210 at a very high frame rate, 1000
to 4000 frames per second, to detect any activity, or the
appearance of the golf club 33. The system 20 can be instructed to
monitor the ROI 210 for a certain brightness provided by the
reflected dots 106a-c. Once the system 20 detects the object in the
ROI 210, the cameras are instructed to gather information on the
object. FIG. 7 illustrates the object or golf club, shown as
reflective dots 106a-c, as entering the field of view 100.
[0058] As the golf club 33 tracks through the field of view 100,
the CMOS sensor array 200 creates new ROIs the encompass the
reflective dots 106a-c. As shown in FIG. 8, the golf club 33 (shown
by the reflective dots 106a-c) has moved from its position in FIG.
7. As shown in FIG. 9, a second ROI 215 is established around the
golf club 33. It is preferably to create an ROI having a minimum
size since the frame rate is increased as the number of active
pixels 205 is reduced. Some CMOS cameras only allow reduction in
the number of columns which would limit the frame rate.
[0059] As the object or golf club 33 moves through the field of
view 100, the current ROI preferably overlaps the previous ROI in
order to better track the movement of the object or golf club 33.
As shown in FIG. 10, the current ROI 220 (shown by bold dashed
lines) overlaps the previous ROI 217 (shown by small dashed lines).
FIG. 11 illustrates the CMOS sensor array 200 for ROI 220.
[0060] FIGS. 12 and 13 illustrate the continued movement of the
object or golf club 33 through the field of view 100 and the new
ROI 225 encompassing the current position of the golf club 33.
[0061] FIG. 14 is a flow chart of a method 300 of using the system
20 of the invention. At box 301, the full CMOS sensor array is
active similar to FIG. 4. At box 302, an object such as a golf club
33 is detected within the field of view 100. If analyzing a
golfer's swing, this first detection may be the golfer addressing
the golf ball 32. During this address of the golf ball, the system
20 may be gathering information concerning the orientation of the
club head to the golf ball as the golfer adjusts the position of
the golf club to strike the golf ball. The CMOS sensor array 200 is
operating at a minimum frame rate since all of the active pixels
205 are activated. However, since the movement of the golf club 33
is slow, this minimum frame rate is sufficient to gather the
necessary information.
[0062] At box 303, a ROI is created around the object. At box 304,
the objected is monitored at a higher frame rate. At box 305, the
object is removed from the field of view. If the golf club 33 is
monitored during address at box 304, increased information is
provided until the golf club is taken away for a swing.
Alternatively, if a golf ball 32 is monitored at prior to impact,
at impact and post impact, then the ROI is created around the golf
ball 32 until it leaves the field of view 100.
[0063] FIG. 15 is a flow chart of a specific method 310 for
analysis of a golf club at address. At box 311, the CMOS sensor
array 200 monitors the field of view 100 at a minimum frame rate.
At box 312, the indication markers (reflective dots or other like
markers) on the golf club 33 are detected within the field of view
100. At box 313, a ROI is created around the indication markers of
the golf club 33. At box 314, the golf club 33 is monitored at a
higher frame rate within the ROI. At box 315, the golf club 33 is
taken away from the field of view 100.
[0064] FIG. 16 is a method 320 for using the system 20 to monitor
an object. At box 321, a portion of the field of view 100 is
monitored at a maximum rate, similar to the ROI 210 established and
monitored in FIG. 6. At box 322, an object is detected within the
ROI. At box 323, a first ROI is created around the object. At box
324, a plurality of ROIs are created around the object as it tracks
through the field of view 100. At box 325, information is provided
on the movement of the object through the field of view.
[0065] FIG. 17 is a flow chart of a method 330 for using the system
to monitor a golf club. At box 331, a portion of the field of view
100 is monitored at a maximum rate, similar to the ROI 210
established and monitored in FIG. 6. At box 332, a golf club 33, or
more specifically the indication markers of the golf club 33, is
detected within the ROI. At box 333, a first ROI is created around
the indications markers on the golf club 33. At box 334, a
plurality of ROIs is created around the indication markers as the
golf club tracks through the field of view 100. At box 335,
information is provided on the movement of the golf club through
the field of view to determine the swing properties of the
golfer.
[0066] FIG. 18 is a flow chart of a method 340 for using the system
to monitor a golf ball during launch. At box 341, an ROI is created
around the golf ball prior to impact with a golf club. At box 342,
movement of the golf ball 32 is detected by the system 20. At box
343, a plurality of ROIs is created around the golf ball during the
initial launch of the golf ball subsequent to impact with a golf
club. At box 344, the system analyzes the movement of the golf ball
to provide launch parameters of the golf ball 32.
[0067] The CMOS sensor array 200 can operate at frames rates 4000
frames per second for a very small ROI. However, processing time
between images or frames requires preferably less than 500
microseconds, and preferably less than 250 microseconds. The
processing time is needed to analyze the image to determine if an
object is detected and if the object is moving.
[0068] The system 20 may be calibrated using many techniques known
to those skilled in the pertinent art. One such technique is
disclosed in U.S. Pat. No. 5,803,823, which is hereby incorporated
by reference. The system 20 is calibrated when first activated, and
then may operate to analyze golf swings for golfers until
deactivated.
[0069] As mentioned above, the system 20 captures and analyzes golf
club information and golf ball information during and after a
golfer's swing. The system 20 uses the images and other information
to generate the information on the golfer's swing. The golf club 33
has at least two, but preferably three highly reflective points
106a-c preferably positioned on the shaft, heel and toe of the golf
club 33. The highly reflective points 106a-c may be inherent with
the golf club design, or each may be composed of a highly
reflective material that is adhesively attached to the desired
positions of the golf club 33. The points 106a-c are preferably
highly reflective since the cameras 40 and 44 are preferably
programmed to search for two or three points that have a certain
brightness such as 200 out of a gray scale of 0-255. The cameras 40
and 44 search for point pairs that have approximately one inch
separation, and in this manner, the detection of the golf club 33
is acquired by the cameras for data acquisition.
[0070] As shown in FIG. 19, the first row of acquired highly
reflective points 106a (on the shaft) is designated series one, the
second row of acquired highly reflective points 106b (on the heel)
is designated series two, and the third row of acquired highly
reflective points 106c (on the toe) is designated series three. The
first row is the acquired highly reflective points 106a from the
shaft, the second row is the acquired highly reflective points 106a
from the heel, and the third row is the acquired highly reflective
points 106a from the toe. The following equation is used to acquire
the positioning information:
d=[(Ptx-Pnx).sup.2+(Pty-Ptny).sup.2 . . . ].sup.1/2
[0071] where d is the distance, Ptx is the position in the x
direction and Pty is the position in the y direction.
[0072] The system 20 may use a three point mode or a two point mode
to generate further information. The two point mode uses V.sub.toe,
V.sub.heel and V.sub.clubtop to calculate the head speed.
V.sub.toe=[(Ptx.sub.3-Ptx.sub.1).sup.2+(Pty.sub.3-Pty.sub.1).sup.2+(Ptz.-
sub.3-Ptz.sub.1).sup.2].sup.1/2[1/.delta.T]
V.sub.heel=[(Ptx.sub.3-Ptx.sub.1).sup.2+(Pty.sub.3-Pty.sub.1).sup.2+(Ptz-
.sub.3-Ptz).sup.2].sup.1/2[1/.delta.]
V.sub.clubtop=[V.sub.toe+V.sub.heel][1/2]
Vy=[(y.sub.3heel-y.sub.1heel).sup.2+(y.sub.3toe-1toe).sup.2].sup.1/2[1/(-
2*.delta.T)]
Vz=[(z.sub.3heel-Z.sub.1heel).sup.2+(z.sub.3toe-z.sub.1toe).sup.2].sup.1-
/2[1/(2*.delta.T)]
[0073] This information is then used to acquire the path angle and
attack angle of the golf club 33. The Path angle=sin.sup.-1(Vy/[V])
where [V] is the magnitude of V.
[0074] The attack angle=sin.sup.-1(Vz/[V]), and the dynamic loft
and dynamic lie are obtained by using Series one and Series two to
project the loft and lie onto the vertical and horizontal
planes.
[0075] The two point mode uses the shaft highly reflective point
106a or the toe highly reflective point 106c along with the heel
highly reflective point 106b to calculate the head speed of the
golf club, the path angle and the attack angle. Using the shaft
highly reflective point 106a, the equations are:
V.sub.heel[(Ptx.sub.3-Ptx.sub.1).sup.2+(Pty.sub.3-Pty.sub.1).sup.2+(Ptz.-
sub.3-Ptz.sub.1).sup.2].sup.1/2[1/.delta.]
V.sub.shaft[(Ptx.sub.3-Ptx.sub.1).sup.2+(Pty.sub.3-Pty.sub.1).sup.2+(Ptz-
.sub.3-Ptz.sub.1).sup.2].sup.1/2[1/.delta.T]
V.sub.center=1.02*(V.sub.shaft+V.sub.heel)
Vy=[(y.sub.3heel-y.sub.1heel).sup.2+(y.sub.3shaft-y.sub.1shaft).sup.2].s-
up.1/2[1/(2*.delta.T)]
Vz=[(z.sub.3heel-Z.sub.1heel).sup.2+(z.sub.3shaft-Z.sub.1shaft).sup.2].s-
up.1/2[1/(2*.delta.T)]
[0076] The Path angle=sin.sup.-1(Vy/[V]) where [V] is the magnitude
of V.
[0077] The attack angle=sin.sup.-1 (Vz/[V]).
[0078] Using the toe highly reflective point 106c, the equations
are:
V.sub.toe=[(x.sub.3-x.sub.1).sup.2+(y.sub.3-y.sub.1).sup.2+(z.sub.3-z.su-
b.1).sup.2].sup.1/2[1/.delta.T]
V.sub.heel=[(x.sub.2-x.sub.1).sup.2+(y.sub.2-y.sub.1).sup.2+(z.sub.2-z.s-
ub.1).sup.2].sup.1/2[1/.delta.T]
V.sub.clubtop=[V.sub.toe+V.sub.heel][1/2]
[0079] The path angle=sin.sup.-1(Vy.sub.Clubtop/[V.sub.clubtop])
where [V.sub.clubtop] is the magnitude of V.sub.clubtop.
[0080] The attack angle=sin.sup.-1(Vz.sub.clubtop/[V.sub.clubtop])
where [V.sub.clubtop] is the magnitude of V.sub.clubtop.
[0081] The golf ball information is mostly obtained from images of
the golf ball post impact. First, the best radius and position of
the two dimensional areas of interest are determined from the
images. Next, all of the combinations of the golf ball 32 centers
in the images are matched and passed through a calibration model to
obtain the X, Y, and Z coordinates of the golf ball 32. The system
20 removes the pairs with an error value greater then 5 millimeters
to get acceptable X, Y, Z coordinates. Next, the strobe times from
the flash units 42a-b and 46a-b are matched to the position of the
golf ball 32 based on the estimated distance traveled from the
images. Next, the velocity of the golf ball 32 is obtained from Vx,
Vy and Vz using a linear approximation. Next the golf ball speed is
obtained by calculating the magnitude of Vx, Vy and Vz.
[0082] The launch angle=sin.sup.-1 (Vz/golf ball speed),
[0083] and the spin angle=sin.sup.-1 (Vy/golf ball speed).
[0084] Next, the system 20 looks for the stripes 108a-b, as shown
in FIGS. 20 and 20A, on the golf ball 32 by using a random
transformation searching for the spot of greatest contrast. X, Y
and Z coordinates are used with the arc of stripe 108a and the arc
of stripe 108b to orient the arc on the golf ball. Then, the system
20 determines which arc is most normal using
(X.sup.2+y.sup.2).sup.1/2.
[0085] Next, the .theta. angle of the golf ball 32 is measured by
taking the first vector and the second vector and using the
equation:
.theta.=cos.sup.-1[(vector A1)(vector A2)]/([V.sub.1][V.sub.2])
[0086] where [V.sub.1] is the magnitude of V.sub.1 and [V.sub.2] is
the magnitude of V.sub.2.
[0087] As the golf ball 32 rotates from the position shown in FIG.
20 to the position shown in FIG. 20A, the angle .theta. is
determined from the position of vector A at both rotation
positions. This allows for the spin to be determined. The back spin
is calculated and applied to the first set of axis with a tilt axis
of zero. The resultant vectors are compared to those of the next
image and a theta is calculated for each of the vectors. This is
done for each tilt axis until the Theta between the rotated first
set of axis and the second set of axis is minimized.
[0088] The following is an example of how the system captures and
analyzes golf club information and golf ball information during and
after a golfer's swing. The golf club information includes golf
club head orientation, golf club head velocity, and golf club spin.
The golf club head orientation includes dynamic lie, loft and face
angle of the golf club head. The golf club head velocity includes
path of the golf club head, attack of the golf club head and
downrange information. The golf ball information includes golf ball
velocity, golf ball launch angle, golf ball side angle, golf ball
speed manipulation and golf ball orientation. The golf ball
orientation includes the true spin of the golf ball, and the tilt
axis of the golf ball which entails the back spin and the side spin
of the golf ball.
[0089] The system 20 pairs the points 106a-c, verifying size,
separation, orientation and attack angle. Then, the system 20
captures a set of six points (three pairs) from a first find as
shown in FIGS. 21 and 21A. Then, the system 20 searches above and
below the three pairs for a second find, as shown in FIG. 22 and
23. The repeated points 106 are eliminated and the results are
displayed from the find, as shown in FIGS. 24 and 25. The points of
the final pairs are processed by the computer 22 and displayed as
shown in FIG. 26.
[0090] Next the speed of the head of the golf club 33 is determined
by the system 20 using the equations discussed above.
[0091] Next the path angle and the attack angle of the golf club 33
is determined by the system 20. Using the methods previously
described, the attack angle is determined from the following
equation:
[0092] Attack angle=-a tan (.delta.z/.delta.x)
[0093] Where .delta.z is the z value of the midpoint between
106a.sub.1 and 106b.sub.1 minus the z value of the midpoint between
106a.sub.3 and 106b.sub.3. Where .delta.x is the x value of the
midpoint between 106a.sub.1 and 106b.sub.1 minus the x value of the
midpoint between 106a.sub.3 and 106b.sub.3.
[0094] The path angle is determined from the following
equation:
[0095] path angle=-a tan (.delta.y/.delta.x)
[0096] Where .delta.y is the y value of the midpoint between
106a.sub.1 , and 106b.sub.1 minus the y value of the midpoint
between 106a.sub.3 and 106b.sub.3. Where .delta.x is the x value of
the midpoint between 106a.sub.1 and 106b.sub.1 minus the x value of
the midpoint between 106a.sub.3 and 106b.sub.3.
[0097] Next, the golf ball 32 data is determined by the system 20.
First, the thresholding of the image is established as shown in
FIG. 27, at a lower gray scale value, approximately 100 to 120, to
detect the golf ball 32. The golf ball 32 is shown at a first
position 103, a second position 104a, a third position 104b, a
fourth position 104c and a fifth position 104d. Next, well-known
edge detection methods are used to obtain the best golf ball 32
center and radius, as shown in FIG. 28. Next, the stereo
correlation of two dimensional points on the golf ball 32 is
performed by the system 20 as in FIG. 29, which illustrates the
images of the first camera 40 and the second camera 44.
[0098] Next, as shown in FIG. 30, with the positioning information
provided therein, the speed of the golf ball 32, the launch angle
of the golf ball 32, and the side angle of the golf ball 32 is
determined by the system 20. The speed of the golf ball is
determined by the following equation:
[0099] Golf ball
speed=[.delta.X.sup.2+.delta.Y.sup.2+.delta.Z.sup.2].sup.1/2/.delta.T.
For the information provided in FIG. 30, the speed of the golf
ball=[(-161.68+(-605.26)).sup.2+(-43.41+(-38.46)).sup.2+(-282.74+(-193.85-
)).sup.2].sup.1/2/(13127-5115), which is equal to 126 MPH once
converted from millimeters over microseconds.
[0100] The launch angle of the golf ball 32 is determined by the
following equation:
Launch angle=sin.sup.-1(Vz/ golf ball speed) where
Vz=.delta./.delta.T. For the information provided in FIG. 30,
Vz=[(-282.74+(-193.85)]/(13127-5115)=11.3 MPH. Then, the launch
angle=sin.sup.-1(1.4/126.3)=11.3 degrees.
[0101] The side angle of the golf ball 32 is determined by the
following equation: Side angle=sin.sup.-1(Vy/golf ball speed) where
Vy=.delta.Y/.delta.T. For the information provided in FIG. 30,
Vy=[(-43.41+(-38.46)]/(13127-5115)=1.4 MPH. Then, the side
angle=sin.sup.-1(1.4/126.3)=0.6 degrees.
[0102] The ball spin is calculated by determining the location of
the three striped on each of the acquired golf balls. Matching each
axis in the field of view and determine which of the axis is
orthogonal to the vertical plane. The spin is then calculated
by:
.theta.=a cos ((vectorA1 dot vector A2)/mag(v1)*mag(v2)) as
discussed above.
[0103] From the foregoing it is believed that those skilled in the
pertinent art will recognize the meritorious advancement of this
invention and will readily understand that while the present
invention has been described in association with a preferred
embodiment thereof, and other embodiments illustrated in the
accompanying drawings, numerous changes, modifications and
substitutions of equivalents may be made therein without departing
from the spirit and scope of this invention which is intended to be
unlimited by the foregoing except as may appear in the following
appended claims. Therefore, the embodiments of the invention in
which an exclusive property or privilege is claimed are defined in
the following appended claims.
* * * * *