U.S. patent application number 11/198570 was filed with the patent office on 2005-12-08 for swing position recognition and reinforcement.
This patent application is currently assigned to Recognition Insight, LLC. Invention is credited to Funk, Conley Jack, Funk, John Marlin.
Application Number | 20050272517 11/198570 |
Document ID | / |
Family ID | 35449683 |
Filed Date | 2005-12-08 |
United States Patent
Application |
20050272517 |
Kind Code |
A1 |
Funk, Conley Jack ; et
al. |
December 8, 2005 |
Swing position recognition and reinforcement
Abstract
A method and device is used to teach and simulate swing
mechanics. A camera is coupled to a computer such that frames
including an image of a golfer swinging a golf club may be
captured. A key part of the image is identified by the computer in
sequential frames captured from the camera, and the image is
compared to swing mechanics of a known standard golfer. The
position of the known standard golfer is capable of following the
natural swing of a student golfer, and the method and device are
capable of providing real-time feedback to the student golfer
during the golfer's swing. An instant replay may be used to
reinforce good swing mechanics. A marker attachment may be used to
assist in tracking and analyzing the swing mechanics of the images.
Parameters relating to club angle and apparent club length may be
compared to a known standard for a plurality of reference swing
positions in order to determine the swing mechanics of the student
golfer during practice instruction and within a golf simulation
game to determine ball trajectory. A ball launch monitor may be
integrated with the image analysis, which improves the
effectiveness of the method and device synergistically.
Inventors: |
Funk, Conley Jack; (Naples,
FL) ; Funk, John Marlin; (Naples, FL) |
Correspondence
Address: |
CHRISTOPHER PARADIES, PH.D.
FOWLER WHITE BOGGS BANKER, P.A.
501 E KENNEDY BLVD, STE. 1900
TAMPA
FL
33602
US
|
Assignee: |
Recognition Insight, LLC
Naples
FL
|
Family ID: |
35449683 |
Appl. No.: |
11/198570 |
Filed: |
August 4, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11198570 |
Aug 4, 2005 |
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10345651 |
Jan 17, 2003 |
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10345651 |
Jan 17, 2003 |
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09878447 |
Jun 11, 2001 |
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6533675 |
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Current U.S.
Class: |
473/222 |
Current CPC
Class: |
A63B 24/0003 20130101;
A63B 2220/806 20130101; A63B 2220/807 20130101; A63B 69/3632
20130101; A63B 15/00 20130101 |
Class at
Publication: |
473/222 |
International
Class: |
A63B 069/36 |
Claims
What is claimed is:
1. A device for a golfer to practice golf swing mechanics with a
golf club, the device comprising: a computer; and a camera coupled
to the computer such that the computer is capable of capturing
video frames from the camera of an image of the golfer and at least
a portion of the club, such that when the golfer swings the club at
the golfer's own pace, the computer matches at least one key part
of the image to a known standard, the computer determines a club
position from the at least one key part of the image, and the
computer provides feedback to the golfer based on a divergence of
the position of the club of the golfer from the position of the
club of the known standard.
2. The device of claim 1, wherein the camera is positioned face on
to the golfer, and the computer measures a parameter related to a
length of the club and compares the measured parameter related to
the length to a known standard length for at least one position of
the club.
3. The device of claim 2, further comprising a marker attachment
having a spacer member with a first marker at one end of the spacer
member and a second marker at an opposite end of the spacer member,
wherein the computer determines the length of the marker attachment
by determining the distance between the first marker and the second
marker.
4. The device of claim 3, wherein the distance is measured in
pixels.
5. The device of claim 3, wherein the computer compares the length
of the marker attachment to the known standard length for a
plurality of club positions.
6. The device of claim 5, wherein the plurality of club positions
is at least thirty club positions per second.
7. The device of claim 5, wherein the plurality of club positions
is at least sixty club positions per second.
8. The device of claim 3, wherein the marker attachment has a
plurality of markers and at least one of the markers comprises an
orb, and the orb has at least two colors such that the computer is
capable of determining rotation of the marker attachment from the
changing fraction of the at least two colors that are visible in
the image.
9. The device of claim 8, wherein the rotation of the marker
attachment is used to determine divergence from a known
standard.
10. The device of claim 9, wherein the divergence is used to
calculate the effect on a trajectory of a ball in a golf
simulator.
11. The device of claim 10, further comprising a ball launch
monitor, wherein the launch monitor is capable of determining the
speed and direction of a ball after impact with a head of the club,
and the computer determines the trajectory of ball in a golf
simulator based on the speed and direction of the ball and the
rotation of the shaft of the club.
12. The device of claim 10, wherein the computer is capable of
providing an instant replay that instructs the golfer how to
correct improper golf swing mechanics to improve the trajectory of
the golf ball.
13. The device of claim 1, wherein the camera is positioned
downline of the golfer, and the computer measures a parameter
related to an angle of a shaft of the club and compares the
measured parameter related to the angle to a known standard angle
for at least one position of the club.
14. The device of claim 13, wherein the at least one key part
includes the point where a grip of the club intersects the shaft of
the club.
15. The device of claim 14, wherein the point where the grip
intersects the shaft is marked by a first marker.
16. The device of claim 15, wherein the first marker is attached at
one end of a spacer member having a second marker attached at an
opposite end.
17. The device of claim 16, wherein the marker attachment has a
plurality of markers and at least one of the markers comprises an
orb, and the orb has at least two colors such that the computer is
capable of determining rotation of the shaft from the changing
fraction of the at least two colors that are visible in the image
during rotation of the shaft of the club.
18. The device of claim 17, wherein the rotation of the shaft is
used to determine divergence from rotation of a known standard for
rotation of the shaft of the club.
19. The device of claim 18, wherein the divergence is used to
calculate the effect on a trajectory of the ball in a golf
simulator.
20. The device of claim 14, wherein a rotation of the shaft of the
club is determined from the image of a head of the club.
21. The device of claim 20, further comprising a ball launch
monitor, wherein the launch monitor is capable of determining the
speed and direction of the ball after impact with a head of the
club, and the computer determines the trajectory of the ball in a
golf simulator based on the speed and direction of the ball and the
rotation of the shaft of the club.
22. An interactive method of tracking and analyzing golf swing
mechanics of a golfer using a golf club, the method comprising:
viewing the golfer with a video camera; coupling the video camera
to a computer such that the computer is capable of capturing images
from the video camera; determining a key part from the images;
tracking the position of the golf club during a swing using the key
part; comparing the position of the golf swing to a reference
position of a known standard swing; providing feedback to the
golfer such that the golfer is capable of improving the swing
mechanics.
23. The method of claim 22, wherein the step of providing feedback
includes providing visual feedback or audible feedback or both
visual feedback and audible feedback.
24. The method of claim 23, wherein the visual feedback includes:
superimposing a pattern of a golfer having a known standard golf
swing mechanics over the image of the golfer on a display screen
based on the key position identified by the computer from the
image.
25. The method of claim 24, wherein the audible feedback is capable
of instructing the golfer about at least one improper aspect of
swing mechanics in real time during a swing by the golfer.
26. The method of claim 25, wherein the audible feedback is capable
of informing the golfer of a flat back swing based on image
analysis of the image by the computer.
27. The method of claim 23, wherein the step of superimposing
includes: advancing the image from one frame to the next in real
time and superimposing the pattern of the golfer having a known
standard golf swing mechanics to each of a plurality of sequential
images of the golfer in each frame based on the key position
identified by the computer from the image.
28. The method of claim 27, further comprising: attaching a marker
attachment on a shaft of the club of the golfer.
29. The method of claim 28, further comprising: exhibiting a
surface of the marker attachment having a color pattern thereon;
analyzing the color pattern; comparing the color pattern of the
marker of the golfer to the color pattern of a known standard
golfer; determining divergence from the color pattern of the known
standard golfer; and providing the golfer feedback concerning the
divergence.
30. The method of claim 29, wherein the feedback is audible.
31. The method of claim 29, wherein the feedback is capable of
informing the golfer of a slice or a hook.
32. The method of claim 31, wherein the feedback is a golf
simulator capable of showing the trajectory of the golf ball of the
golfer compared to the trajectory of the golf ball of the known
standard golfer.
33. The method of claim 32, wherein the feedback includes an
explanation of the defect in golf mechanics of the golfer and
providing drills to practice correcting of the defect in golf
mechanics.
34. The method of claim 33, wherein the feedback includes repeating
the shot and showing a comparison of the original trajectory, the
repeated trajectory and the known standard trajectory.
35. The method of claim 22, wherein the step of determining a key
part from the images includes determining the coordinates of a
first marker attached to a shaft of the club at the intersection of
a grip and a shaft of the club.
36. The method of claim 35, wherein the step of tracking the
position of the golf club includes determining the position of at
least one additional marker spaced at known distance from the first
marker, determining a linear fit from the first marker through the
at least one additional marker, wherein an angle from a fixed
direction from the first marker to the line of the linear fit is
capable of being determined.
37. The method of claim 36, wherein the step of tracking the
position of the golf club further comprises counting the number of
pixels from the first marker to the at least one additional
marker.
38. The method of claim 37, wherein the step of tracking the
position of the golf club further comprises counting the number of
pixels from a center of mass of the body to the position of the
first marker.
39. The method of claim 38, wherein the step of comparing the
position of the golf swing to a reference position of a known
standard swing includes comparing at least one of the measurements
made in the step of tracking the position to at least one related
value measured from the known standard swing at the reference
position associated with the actual position of the first marker of
the golfer, the at least one of the measurements made in the step
of tracking the position being selected from the group of
measurements consisting of the number of pixels from a center of
mass of the body to the position of the first marker, the number of
pixels from the first marker to the at least one additional marker,
the coordinates of the position of the center of mass of the
golfer's head, and the angle from a fixed direction from the first
marker to the line of the linear fit.
40. The method of claim 3, wherein the step of comparing the
position of the golf swing to a reference position of a known
standard swing includes comparing at least two of the measurements
made in the step of tracking the position to at least two related
values measured from the known standard swing at the reference
position associated with the actual position of the first marker of
the golfer.
41. The method of claim 22, wherein the step of viewing the golfer
views the golfer from a plurality of cameras positioned for
different views of the golfer.
42. The method of claim 22, further comprising a step of analyzing
the brightness and gray properties of known color patterns of a
marker attachment and reporting light conditions to the golfer.
43. The method of claim 22, further comprising a step of disposing
the camera a proper distance from the golfer during setup by
comparing the height of the golfer to the height of a known
standard golfer.
44. The method of claim 22, further comprising using a marker
attachment as a pointing device to control the computer.
45. The method of claim 44, wherein the step of using a marker
attachment includes the step of mirroring the image of the golfer
on the display.
46. The method of claim 22, further comprising: selecting a type of
golf club; taking a practice swing with the type of golf club;
viewing the practice swing in real-time during the practice swing;
replaying the practice swing; and analyzing the practice swing
step-by-step audibly commenting on the swing mechanics during each
step having comments associated with the step.
47. The method of claim 22, further comprising: predicting the
trajectory of a ball; and determining from the trajectory the lie
of the ball in a simulated golf environment.
48. The method of claim 47, further comprising: using a launch
monitor to determine ball speed and initial direction of the ball
when using a putter for long putts, a wedge, an iron, a wood or a
driver; attaching a marker having plurality of colors or patterns
on the club; predicting the effect of ball rotation imparted by
rotational position of the club at impact on the trajectory of the
ball from image analysis of the marker having a plurality of colors
using an image analyzer; and using the image analyzer to determine
the ball speed and initial direction of the ball when using a
putter for a short putt, when the image analyzer is capable of
improving the accuracy of the simulation of the short putt.
49. The method of claim 48, further comprising a step of including
a plurality of players in the golf simulation.
50. The method of claim 49, wherein the plurality of players are
disposed in different locations and are playing over an electronic
network.
51. A simulation system for a player comprising: a device for
practicing swing mechanics, the device comprising a computer, and a
camera coupled to the computer such that the computer is capable of
capturing video frames from the camera of a marker device on a
shaft; the marker device having a plurality of orbs, each having an
anti-reflective surface, the plurality of orbs including: a first
orb; a second orb disposed at a distance from the first orb; a
first bi-colored orb of a first color and a second color; and a
second bi-colored orb of a second color and a first color; wherein
the first bi-colored orb has the first color on a left half and the
second color on a right half and the second bi-colored orb has the
first color on a right half and the second color on a left half
such that the color of the second bi-colored orb is a mirror image
of the color of the first bi-colored orb, such that, when the
player swings the shaft at the player's own pace, the system
identifies swing mechanics information, including: determining the
coordinates of the first orb in relation to a center of mass of at
least a portion of the player; fitting a linear fit from the first
orb through the second orb, providing an angle of the shaft to a
reference direction; measuring the apparent distance between the
first orb and the second orb; and measuring a rotation of the shaft
based on a count of the number of pixels of the second color and
the third color for each of the first bi-colored orb and the second
bi-colored orb; and the system compares the swing mechanics
information to a known standard; and provides real-time visual and
audible feedback to the player.
52. The system of claim 51, wherein the first orb, the second orb
and the third orb have a third color, and the third color is of a
different color than the second color and the third color of the
first bi-colored orb and the second bi-colored orb.
53. A marker attachment comprising a plurality of orbs, each of the
plurality of orbs having an anti-reflective surface, the plurality
of orbs including: a first orb having a uniform surface color; a
second orb of the same color as the first orb disposed at a
distance from the first orb; a third orb of the same color as the
first orb disposed between the first orb and the second orb; a
first bi-colored orb of a second color and a third color; and a
second bi-colored orb of a second color and a third color; wherein
the first bi-colored orb has the second color on a left half and
the third color on a right half and the second bi-colored orb has
the second color on a right half and the third color on a left half
such that the color of the second bi-colored orb is a mirror image
of the color of the first bi-colored orb;
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of
U.S. application Ser. No. 10/345,651, filed Jan. 17, 2003, now
abandoned in favor of this application, which is incorporated
herein by reference in its entirety, which is a
continuation-in-part application of U.S. application Ser. No.
09/878,447 filed on Jun. 11, 2001, now issued as U.S. Pat. No.
6,533,675.
FIELD OF THE INVENTION
[0002] The field relates to golf instruction and golf
simulators.
BACKGROUND AND DESCRIPTION OF PRIOR ART
[0003] A golf swing requires the synchronized actions of more than
80 different muscles in a way that is not particularly intuitive or
consistent with the human framework. Focusing on the totality of
these various muscle movements surpasses the ability of the
conscious mind. This requirement for complex and unnatural muscle
movements is the principle reason why golf is considered to be a
difficult game to master. Even if one is successful in correctly
emulating the precise body movements of a given professional, it is
unclear that the club movements that are actually produced are
correct for a particular person given his or her physical
differences.
[0004] Correct movement of the golf club is the main objective of a
golf swing. If the club moves correctly then learning the
associated body movements becomes a far easier goal. There are as
many swing styles as there are body sizes and shapes, even among
professionals, but the objective of each is to move the club in a
very similar way.
[0005] Training tools exist that focus on body movements during the
golf swing, but none describes or teaches correct club movement in
terms of geometric position of the golf club, club head rotation
and three dimensional shaft direction at every point of the golf
swing. And none performs computer image recognition of the golf
club and body position to guide the club movements, analyze the
swing and predict the ball flight.
[0006] U.S. Pat. No. 6,159,016 compares video recordings of the
body motions of a student to that of an instructor or professional.
But these recordings lack interactivity because it is only after
the student has completed the exercise that he or she can view
comparisons. The computers involved receive and display images but
do not recognize or analyze club or body movements. That task is
left to the student and/or his or her instructor.
[0007] U.S. Pat. No. 6,126,449 allows a student to swing a club
within a body template image of a chosen professional instructor.
The computer receives and displays images but does not recognize
the student's actual club or body movements, leaving the entire
burden of swing analysis to the student and his or her instructor.
Because the golf swing analyzer has no awareness of what the
student is actually doing once the template is set in motion, there
can be no responsive interaction between the student and the
device. No effort is made by the above cited patent to
systematically describe correct body position as a function of
correct golf club movement. Since the motion template of U.S. Pat.
No. 6,126,449 progresses through the swing unconditionally in a
constant predetermined motion without the benefit of position
recognition, the student has no opportunity to initiate motion with
position reinforcement being provided by an intelligent process.
This invention can neither analyze a golfer's swing nor predict his
or her ball flight, nor display a cutout of the golfer's image as
he swings on a golf course background.
[0008] U.S. Pat. No. 6,126,449 also requires the student to
synchronize his or her activities to the timing provided by the
pre-recorded template. The student cannot test or exercise his or
her club movements swinging freely back and forth using variable
timing as he or she can with swing position recognition and
reinforcement.
[0009] In the above noted patent there is an uncertain task in
deciding which professional's templates to use. Then attempting to
emulate the complex body movements executed by that professional
can be very difficult and perhaps of no particular advantage in
achieving the club and body movements that are correct for the
student, given the physical differences between the student and the
professional such as differences in anatomy, physiology,
flexibility, and strength
[0010] U.S. Pat. No. 6,059,668 teaches the effects of club movement
by allowing the student to observe a light that shines in both
directions along the club shaft generated by a device attached to
the golf club shaft. This method does not help the student to know
if the geometric location of the club is correct at any point. This
method fails to detect very common problems, such as that of the
golfer bending his forward arm during the back swing producing a
swing whose arc is too narrow yet able to satisfy criteria
indicating that the swing is correct.
[0011] With nothing other than a light beam to communicate to the
student, the above cited patent lacks the effectiveness and
accuracy of image analysis and video presentation. It suffers from
not being able to review the analysis of a given swing many times
at different speeds. This invention becomes the least effective
during the forward swing before impact while the club is making its
most rapid movement. During this time the student must interpret
the light signals and switch his or her view from the light
pointing toward the grip end of the club to that pointing toward
the head of the club. This invention is unusable outdoors under
bright sunlight and physical adjustments are necessary to the
platform that reflects the beam of light when using clubs of
different lengths.
[0012] U.S. Pat. No. 5,772,449 discloses a method for simulating a
golfer's swing by a two step process that first collects data about
a golfer's club and body movements and then feeds the data to a
commercially available mechanical simulation package. In the second
step, an android computer model attempts to reproduce the golfer's
swing for the primary purpose of determining what kinds of clubs
are best suited to that golfer. This method is not interactive with
the golfer and does not teach or include a pattern of an ideal golf
swing as is explained below.
[0013] Prior inventions have used video recordings of the golf
swings of various professional golfers for comparison to a student
as though they were magic formulas. In fact, many professionals owe
their success more to extensive practice than to excellent
techniques. Since golf tournaments can be seen on national
television every weekend, most of the techniques that amateur
golfers would like to learn have become common knowledge and are
practiced by most professionals. What is needed is a systematic and
effective way to learn and practice these well-known club and body
movements. These techniques can be interactively taught by a
software program that is capable of running on most personal
computers equipped with an inexpensive video camera such as a USB
web cam.
[0014] Thus a longstanding and unresolved need exists for an easy
to use and inexpensive training system that allows a student to
focus precisely on club position and club movement with real-time
interactive assistance. A further need exists for analysis while
practicing back and forth swings with no predetermined timing. The
student should be able to spontaneously perform a sequence of
swings without prior planning or setup. For a proficient and
experienced golfer, this capability provides effective audio and
video feedback during warm-up exercises.
[0015] Previous inventions do not have the benefit of the computer
instantaneously recognizing, analyzing, understanding and
responding to the motion of the student's golf club and reinforcing
the club and body positions. While simulation based on analyzing
the flight of the ball is effective in determining the ball flight,
such simulation is ineffective in correcting a student golfer's
swing mechanics. Even experience golf pros have great difficulty in
determining and explaining the exact cause of a student golfer's
poor swing mechanics. A video camera may be used to analyze the
golf swing, but a student golfer has a hard time understanding what
a correct swing should look like. Known swing analyzers require the
student golfer to pace his or her swing to a moving image of a golf
pro. This artificial and unnatural pacing of the student golfer
causes subtle changes in the swing mechanics, which are not
repeated when the student golfer swings at his or her own pace.
Thus, there is a longstanding need for an image analysis system
that follows the student golfer rather than the student golfer
following the pace of the swing analyzer.
SUMMARY AND OBJECTS OF THE INVENTION
[0016] A golf swing training method and apparatus analyzes the
image of a student golfer and matches certain parameters of the
swing to determine the swing mechanics of the student golfer. The
parameters may be used to provide reinforcing feedback, such as
visual and audible feedback to the student golfer, as the student
golfer is practicing the student golfer's swing mechanics at the
student golfer's own pace. The parameters may be used to accurately
predict the flight path of the ball by determining club head speed,
direction and rotation during the swing and at impact with the
ball. In one example, the parameters are coupled with a simple
launch monitor to determine the flight path of the ball, which
allows a small, inexpensive camera to be attached to the computer
directly.
[0017] In another example, a short club may be used in a limited
area with one or more simulated golf balls during instruction. The
device is capable of teaching good swing mechanics for a club of
any length. In one example, swing position recognition is
accomplished by an attachment of one or more colored spheres just
below the grip on the club shaft. Swing position reinforcement
based upon the recognized step-by-step progress of the golf swing
verifies correct body and club position during a computer-provided
lesson. Swing position recognition also allows the golfer to watch
his or her cutout images swinging at various locations on a
background golf course during a simulated golf game. When the
computer has recognized and analyzed the nature of a particular
golf swing problem and its solution, then the presentation to the
student is more effective using computer generated graphics and
audio methods. Since the computer's recognition software can
correlate the club position with the position of the student's body
parts, a more focused and systematic approach can be taken by the
student to learn to swing correctly. Receiving a quantitative
rating based upon the quality of the swing movements and viewing
the predicted ball flight makes learning and practicing more
enjoyable, taking the mystery out of the analysis of golf swing
mechanics.
[0018] When the tracking process is applied to a simulated golf
game, the golfer can watch his or her own image swinging on the
simulated golf course and then observe the ball in flight and as it
lands. He or she can then view a replay or an in depth step-by-step
analysis of the previous swing before proceeding. In one example,
the flight path of the golf ball is predicted based on the swing
mechanics and/or a launch monitor and is compared to the flight
path of a virtual pro.
[0019] In one example, the parameters measure a student golfer's
swing mechanics against a semi-circular back swing plane orbit that
is followed by a circular forward swing plane orbit. The locations
within these orbits serve as reference points for the computer to
recognize the correct club movements and body positions that
comprise the ideal golf swing. These swing plane orbits can be
further differentiated to describe swing planes with correct three
dimensional angles that correspond to the effective club lengths of
a short, medium or long club.
[0020] The derivation of these swing plane orbits is based upon
analysis of a database of swing mechanics of many professional
golfers. The database allows the correct swing to be superimposed
on the student golfer's swing at the student golfer's own pace.
Since the student golfer's swing mechanics are recognized in real
time, the virtual pro follows the student golfer rather than the
other way around. This greatly improves the effectiveness of the
analysis, because the student golfer takes a normal swing along
with all of the normal mistakes.
[0021] In a synchronized, slow motion process that revealed a
pattern of an ideal swing mechanics common to substantially all
successful professional golfers, a pattern developed. The pattern
showed a semi-circular swing plane orbit for the golfer's hands
during the back swing and a separate circular swing plane orbit for
the golfer's hands during the forward swing. These swing plane
orbits were easily extendable to an area of the club shaft near the
golfer's hands. The choice of the location of the club shaft near
the golfer's hands as a reference point was also valuable to keep
the swing plane orbits as small as possible so the video camera's
recognition capabilities are optimized by having the golfer as
close to the camera as possible.
[0022] The swing plane orbits may automatically determined while
the golfer assumes his or her normal stance by considering the
height and other physical characteristics of the golfer. In one
example, the image analysis system instructs the student golfer to
position the camera according to these same metrics, eliminating
the need for the student golfer to measure the distances with a
tape measure or other measuring device.
[0023] The proper golf swing mechanics may be further reinforced by
several calibrating movements. The swing plane orbital locations
form a basis for evaluating club shaft direction, clubface rotation
and overall body position during a golf swing. They form the basis
for swing position recognition and reinforcement that displays a
humanoid pattern that represents the ideal club and body
positions.
[0024] In one example, a marker attachment is placed on the shaft
below the golf club grip, such as an orb or a set of orbs.
Preferably, the material and/or the external coating on the orbs is
selected to have an anti-reflective surface, such that
substantially no glare is perceived by the camera from the orb or
orbs. In one example, the orbs are identifiable by different
colors. The image analysis algorithms may distinguish one orb from
the other or one portion of an orb from another portion of the orb
by the difference in color. Furthermore, blurring of the color may
be used by the algorithms to analyze the golf swing mechanics.
[0025] The attachment may be tracked in real time by a software
program that receives video camera images. The use of the
attachment provide more information with a low resolution camera
and lower frame rate than is possible with the same equipment
without the attachment. For instance, a two-colored orb having one
hemisphere in one color and the other hemisphere in another color
may be used to determine club rotation. This allows the analyzer to
determine whether the club face is open or closed at impact with
the ball, which is an important parameter that is not measured by
simple launch monitors or expensive infrared golf ball flight
monitors, which cannot accurately determine ball rotation. The
software program continuously monitors the position of the
spherical attachment to determine if the club is in a correct swing
plane orbital location and compares the student golfer's swing
mechanics to a virtual pro. Any recognizable patterns on the
attachment may be used to analyze the rotation of the club shaft
that corresponds to the position of the clubface at a given swing
plane orbit location and the direction of the club shaft. If camera
resolution and frame rate are adequate, the system is capable of
monitoring the rotation of the club head and/or the hands of the
golfer. In this case, an attachment is not required, but image
analysis techniques are used to recognize the outline of the club
head or the hands and are compared with the appearance as the head
and/or hands are rotated.
[0026] In one preferred embodiment, four distinct spheres are used
to achieve quality recognition when slow camera speed causes the
swinging club image to streak. In the downline view that is often
used by actual professional trainers, the position of the
solid-color balls is used to determine the club shaft's
two-dimensional angle. A ball that has two dissimilarly colored
hemispheres is divided in the same direction as the club shaft and
is viewed to determine club's face rotation. Another ball may have
two dissimilarly colored hemispheres divided perpendicularly to the
club shaft. This ball, the measured club length, and attachment
location determine the club shaft's three-dimensional angle for
adherence to the ideal swing plane as the camera sees the golfer
along the downline view.
[0027] Although the downline view is commonly used by golf pros, it
is difficult to see the body movements and swing arcs from the
downline view. In one example, a student golfer may position the
camera for a face view of the student golfer. This usually feels
more natural for the student golfer. In this case, the image
analyzer is capable of determining the swing plane position merely
by the location of key points of the arms and apparent club shaft
length. This provides for a very rapid determination of swing
mechanics errors and real time feedback to the student golfer even
using very inexpensive equipment. A camera and image analyzer with
a frame capture rate of less than 30 frames per second may be used
to analyze such problems as a flat back swing and other swing
mechanics. Indeed, the one-dimensional, apparent shaft length and
position of the arms is able to accurately determine the
two-dimensional swing plane and three-dimensional club position.
This surprising and unexpected capability allows the system
resources to be used to provide improved graphics and/or better
determine rotation of the club in real time. Image analysis of
apparent club length is easily determined even from grainy camera
shots by measuring the length between the easily recognized club
head and the golfer's hands. The position of the golfer's hands may
also be used as a key point in determining the position of the
swing. An attachment device, as discussed previously, further
improves the capability of the system to analyze the swing
mechanics with marginal hardware.
[0028] A conventional personal computer control interface such as a
mouse or keyboard may be used to select the analysis activities,
options and displays. In an alternative embodiment, the golfer
controls the sequence of activities and choices during his computer
lesson or golf game by moving the club attachment as a pointer onto
a selection button. This feature permits the golfer to make various
choices while remaining in his or her normal stance that may be
about five feet from the camera and some distance from the display
screen, keyboard and mouse. The student can use a separate monitor
for each display or use multiple windows of a monitor capable of
displaying combinations of views simultaneously that may show
different views based upon the concurrent use of multiple video
cameras.
[0029] An initial calibration may be used to adjust the camera
position, lighting and position of the limited area platform for
consistent ongoing positioning. During and after the calibration, a
light meter feature is capable of telling the user whether the
light level is dark, dim, normal or bright. The light meter reading
is accomplished by examining the brightness and gray levels of
known colors of the attachment following recognition, for example,
without the need for a separate light meter attachment.
[0030] One display shows the student's image and swing plane orbits
plus the correct club shaft direction and clubface rotation at
various intervals along the swing plane orbital path. Another
display shows a blow-up of the region of the spherical attachment
to precisely view the student's actual club position at that moment
and the relation to the display of the correct club position with
respect to the swing plane orbital location, club shaft direction
and club head rotation. Body movement errors are identified at each
swing plane orbital location and illustrated suggestions for
corrections are offered. Tempo of the swing is evaluated. A USGA
handicap rating is assigned to the swing, the scale for which was
determined statistically by a correlation of many golfer's actual
handicaps versus their level of correctness of swing. Instant
replay of the swing can be done at regular speed or in slow
motion.
[0031] Another object and advantage is to display a computer
generated humanoid image of the correct body position of the
student relative to the current swing plane orbital location of the
club attachment. This provides swing position reinforcement to help
the golfer achieve correct club and body movement. This is an ideal
learning situation since the student golfer takes the initiative
rather than being led through each step and receives real-time
reinforcement for his motion decisions.
[0032] Another analysis activity places the golfer on a golf course
or practice range where the ball flight and distance are predicted
based upon the real-time analysis of the swing leading to and
following the ball impact position. During these activities, the
golfer can see his ball in flight as it travels toward a simulated
green. A replay or detailed analysis can be viewed subsequently for
any swing. An embodiment of the golf course and practice range
activities places a cutout camera image of the golfer onto a
simulated golf course or practice range backgrounds. This cutout
camera image corresponds to the current position of the club
attachment with respect to the ideal swing pattern. As the current
position proceeds near the correct positions of the ideal swing
pattern, the golfer can see himself or herself swing on the golf
course or practice range. In this way, the golfer can combine
simulated play and swing analysis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIGS. 1A-1C illustrate three different swing mechanics at
the same reference position, as captured by a camera in the face on
view of the golfer.
[0034] FIGS. 2A-2C illustrate addition of a marker attachment to
the club shaft of FIGS. 1A-1C.
[0035] FIGS. 3A-3C illustrate the same three swing mechanics at the
same reference position as shown in FIGS. 1A-1C, as captured by a
camera in the downline view of the golfer.
[0036] FIGS. 4A-4C illustrate addition of a marker attachment to
the club shaft of FIGS. 3A-3C.
[0037] FIGS. 5A-5C illustrate a method of tracking the club of the
golfer and overlaying an outline, semi-transparent image of a
virtual pro on the image of the student golfer to provide real-time
feedback during a swing at the golfer's own pace.
[0038] FIG. 6A illustrates a front view of a marker attachment.
[0039] FIG. 6B illustrates a back view of a marker attachment.
[0040] FIG. 6C illustrates the marker attachment of FIGS. 6A and 6B
attached to a club.
[0041] FIG. 7 illustrates a golf simulation having a virtual pro
scene cut-out that follows the image of the golfer at the golfer's
own pace.
[0042] FIG. 8 illustrates a plurality of reference swing
positions.
[0043] FIGS. 9A-9C illustrate a method of setting up the distance
of the student golfer from the camera in the face on view of the
student golfer.
[0044] FIG. 10 illustrates a short "club" for use in confined
spaces having a marker attachment integrated with the short
club.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTION
[0045] A system for improving golf swing mechanics includes a
camera, a computer coupled to the camera, and a program that
analyzes the swing of a golfer. The program may provide immediate
feedback to the golfer, such as visual and audio feedback. Audio
feedback may be provided by the computer or a speaker attached to
the computer, which provides tips for improving the golf swing
mechanics of the golfer while the golfer practices his golf swing
at the golfer's own pace. Visual feedback may be displayed on a
display screen, monitor or any other viewing system, such as
virtual reality headsets and the like. The viewing system is
coupled with and controlled by a computer. For example, visual
feedback shows an image or outline of a known standard, such as a
golf pro or a synthesis taken from a plurality of golf pros. The
image of the known standard may be shown in a position that
corresponds to the current reference swing position of the student
golfer during the student golfer's swing. The current reference
swing position is identified by the system and tracked, and the
image of the known standard is paced to follow the student golfer,
who merely swings at the student golfer's own pace.
[0046] In one embodiment, the student golfer may select a specific
club to use in practicing the golfer's swing. The system matches
the student golfer with a known standard using the same club. In
one drill, the student golfer selects a plurality of clubs and
practical instruction is provided with each club in sequence. By
overlaying the image of a known standard using the same club as the
student golfer over the image of the student golfer, without
forcing the student golfer to change his or her own pace, the
student golfer receives continuous feedback on swing mechanics
during a practice swing. Being able to swing at the golfer's own
pace is a significant advantage, allowing the golfer to concentrate
on swing mechanics and not pace. The overlayed image follows the
golfer and immediately shows the golfer if the golfer's swing
mechanics are diverging from the known standard. In one embodiment,
the student golfer selects the known standard from a menu of known
standards. For example, the student golfer may choose a well known
pro, an actual instructor, a longest drive champion or a composite
known standard based on the combined swings of a plurality of
professional golf instructors.
[0047] In one example, a camera is disposed such that a face-on
view is captured of the golfer and the club, as shown in FIGS.
1A-1C. The golfer's hands, arms, or any feature of the club may be
used to determine where in the swing the golfer is during the
swing. In one example, the image of the golfer is overlayed in real
time with a correct golf swing that most closely matches the
reference swing position of the actual, student golfer. FIGS. 1A-1C
show three examples of a golfer who is in about the same reference
swing position, but each of the three golfers has different swing
mechanics. The position of the hands, the angle of an arm, the
position and length of the shaft or the point of the golf club
where the grip intersects the shaft may be used to determine the
reference swing position, which allows the computer to overlay the
golfer's image with an image of a known standard golfer using
correct golf swing mechanics, such as illustrated in FIGS. 5A-5C,
for example. In one preferred embodiment, the point of the golf
club where the grip intersects the shaft is used as a key part to
determine the reference swing position. This is readily determined
from the images of inexpensive cameras that may be directly
attached to a computer's USB port, for example. Thus, the system
may be very inexpensive and may be used by average golfers or those
new to the sport, which is another advantage over other systems.
With this tracking of the reference swing position, an image of a
virtual pro may be paced to follow the normal pace of the student
golfer in real time on a display using an overlay, outline or
cut-away view of the virtual pro, which may be a default known
standard or a known standard selected by the student golfer or a
trainer assisting the student golfer. Preferably, the virtual pro
is selected to suit the style of play, body build and height of the
student golfer, for example.
[0048] The apparent distance from the grip to the club head may be
determined by the number of pixels between the key part of the club
head and the key part where the grip intersects the club shaft, for
example. This apparent distance, normalized by the length of the
club shaft in pixels, has been found to be the same for most
professional golfers at about the same reference swing positions.
By apparent distance it is meant that the distance is measured from
the image of the club. A club disposed at an angle toward or away
from a camera appears shorter than the same club disposed
perpendicular to a line drawn between the camera and the club
shaft. Thus, the apparent distance between any two points on the
club normalized to the actual known distance between the same two
points provides a measure of the three-dimensional, out-of-plane
angle of the club shaft. Thus, a deviation between a known standard
apparent distance and a measured apparent distance at the same
reference swing position may be used to immediately instruct the
student golfer of a defect in the student golfer's swing mechanics.
For example, the distance in pixels of the shaft in FIG. 1A is 50%
less, indicating a flat plane or flat-back swing plane. FIG. 1C
illustrates a distance in pixels about 50% greater, indicating an
excessively steep plane. This is easily determined in real time
during a student golfer's swing, allowing audible feedback to
inform the student of the problem and/or correction required.
[0049] FIGS. 2A-2C show an example of a golf club having special
markers placed on the shaft of the club. For example, a marker
attachment for use in the system is illustrated in FIGS. 6A-6C. In
FIG. 2A, the golfer is swinging too flat. In FIG. 2C, the golfer is
swinging to steep. In FIG. 2B, the golfer is swinging just right.
As can be seen from the sequence, the camera can determine the
difference between a swing that is too flat, correct and too steep
merely by determining the distance between the markers. If the
distance between the markers is too short, then the swing is too
flat. If the distance is too long, then the swing is too steep.
But, if the distance is correct, during the swing, then the golfer
is swinging in the correct swing plane.
[0050] The method of determining the correctness of a swing using a
camera to capture a face-on view of the golfer has never been used
previously. It has been found that the system is capable of
determining the correctness of the swing plane used by the golfer
merely by analyzing the length of the shaft. The actual length of
the club shaft may be entered by the golfer or may be imaged
directly by the camera. The length of the club shaft during the
swing may be computed as a ratio of the actual shaft length, for
example. By comparing this ratio during the swing to the ratio of a
correctly executed swing, the program is capable of detecting
improper swing mechanics. Then, the program may provide visual or
audio cues or instruction to the golfer to correct the improper
swing mechanics. In one example, the apparent distance between two
points on the shaft is determined by counting the number of pixels
between the center of mass of two key parts of the club, such as
the intersection of the grip and the shaft, the club head or two
markers attached to the club shaft at a known spacing.
[0051] Markers are not required for analyzing the golf swing
mechanics using this method. Even comparatively poor resolution
video images, as shown in FIGS. 1A-1C may be used to determine the
club shaft length by counting the number of pixels between the
golfer's hands and the club head, for example. In one embodiment,
the golfer wears a golf glove having a high contrast to the
background, which helps to identify the golfer's hand. While the
glove may be considered a "marker," it is much less noticeable to
the golfer than the markers used in FIGS. 2A-2C and does not add
any weight to the shaft of the club. Thus, the golfer is more
likely to use the same swing mechanics as during the golfer's
normal swing.
[0052] In another example, such as illustrated in FIGS. 3A-3C, a
camera is disposed in a downline view of a golfer. In a downline
view, it is necessary to analyze both the position of the hands and
the angle of the shaft of the golf club in order to determine
whether the golfer is swinging the club in the correct swing plane.
As illustrated in FIGS. 3A-3C, the angle of the club may be
determined based on the position of hands and the golf club head or
by the shaft directly. Higher resolution images of the shaft or
more complex image analysis algorithms may be required to determine
the angle of the shaft than are required in FIGS. 4A-4C, when
markers are used.
[0053] FIGS. 3A-4C show how the accuracy of the two-dimensional
swing plane is determined relative to three dimensions at a given
swing position for a club shaft with a special attachment from the
down-the-line or downline view. This view is favored by many golf
instructors, who are used to this view from live lessons. At the
specific reference swing positin shown in the figures, the correct
radial angle A from the bottom sphere to the top sphere as shown in
FIG. 4B is the known standard angle determined from observation of
many professional golfers. The flat plane image shown in FIG. 3A
has a shaft angle that is about 30 degrees in a counter clockwise
direction from the preferred angle. The steep plane image shown in
FIG. 3C has a shaft angle that is about 30 degrees in a clockwise
direction from the preferred angle. FIGS. 4A-4C show the same
sequence, except that the marker attachment makes imaging of the
position and angle of the club shaft much easier to accomplish
without using image analysis techniques to capture the actual club
position and angle.
[0054] Tracking
[0055] Tracking involves image recognition in each frame of the
golfer's current swing reference position coordinates. The swing
reference position coordinates may be determined from one or more
identifiable key parts, as discussed previously, such as the hands,
a glove, the intersection between the grip and the shaft or a
marker of a marker attachment. On preferred key part is the point
of the golf club where the grip intersects the shaft. This key part
is a pivot point for wrist cock and wrist release; therefore,
discerning its coordinates serves multiple purposes: identifying
the reference swing position and as a key coordinate in evaluating
the student golfer's swing mechanics.
[0056] Wrist cock occurs when the shaft of the club continues
clockwise motion during backswing. Wrist release occurs during the
forward swing just prior to the head of the club striking the ball.
Proper wrist cock and wrist release are essential for achieving a
powerful drive from the tee, for example. Metrics that determine
the angle of the club of a student golfer compared to a known
standard may be used to discern any problems with wrist cock and
wrist release, if monitored throughout the golfer's swing.
[0057] The reference swing position coordinates are a predetermined
sequential set of image points derived from the swing of a selected
virtual professional golfer. In one embodiment the student golfer
or an instructor chooses the virtual professional golfer. In
another embodiment, the computer matches a virtual professional
golfer having similar body size, approach to the ball and stance
with actual golfer. In yet another embodiment, a default standard
virtual professional golfer is used.
[0058] In one example, the current swing position is the ordinal
number corresponding to the reference swing position coordinates
nearest the current swing position coordinates. Successful
recognition of swing position coordinates may be accomplished by
the identification of key parts, such as parts of the golf club and
parts of the actual golfer's body. For example, key golf club parts
may include the grip, the shaft and/or the club head, and key body
parts may include the hands, the arms, the torso, the legs and/or
the head of the student golfer. For example, the coordinates of
these key parts may be determined based on the center of mass of
pixels identified as a portion of these key parts.
[0059] In one specific example, a special club shaft attachment, as
illustrated in FIG. 6, is used as a key part of the golf club.
Then, the key golf club parts may include the grip 72, the shaft
76, the club head 74 and the special attachment 61 or only the
special attachment 61 may be used. The key body parts may include
only the head of the student golfer or both the head and the center
of mass of the torso, for example. In this specific example, a
green orb nearest the grip 62, which may be spherically shaped, is
compared to two additional green orbs 66, 70 at a known distance
from the first green orb 62 to yield accurate angles for wrist-cock
and swing plane comparisons, as illustrated in FIGS. 2A-2C and
4A-4C, for example. In one example, the club head 74, club grip 72
and shaft 76 may be used to reinforce the probability of an
accurate match. In this example, even if any of the club head 74,
club grip 72 and shaft 76 position information are not captured by
the system, the system is still capable of tracking the current
swing position.
[0060] Additional orbs 64, 68 on the marker attachment device 61
are bi-colored blue and red. It will be apparent from FIG. 6 that
the two orbs 64, 68 are positioned on the shaft 76, and whereas one
is red on the left 69, the other is red on the right 63, as viewed
from the front view of FIG. 6A. One advantage of using two
additional markers 64, 68 is that the colors red and blue are not
uniformly captured by the camera in all lighting conditions;
however, using both of the markers 64, 68 oppositely oriented in a
mirror image configuration provides a reliable measure of the
angular rotation of the club shaft 76. Determination of rotation of
the club shaft 76 may be used to determine if the club face is open
or closed upon contact with the ball, which may be used to
determine if the ball will slice or hook, for example. In one
embodiment, the image analyzer counts the number of red and blue
pixels for each of the bi-colored orbs 64, 68. As the club shaft
rotates, the number of red pixels and blue pixels changes for each
of the orbs 64, 68. It has been found that, even if the speed of
the shaft and the frame rate of the camera cause streaking of the
image of the balls 64, 68, an accurate count of blue and red pixels
may be determined. The relative ratio of red to blue or blue to red
provides a reliable measure of the rotation of the shaft.
Reliability is improved by having two bi-colored balls 64, 68
having mirror imaged colors, because the effects of lighting on
color saturation on the CCD is easily discerned and corrected. For
example the sum of the count for red pixels of the first orb 64 and
the count for blue pixels for the second orb 68 may be compared to
the sum of the count of the blue pixels of the first ball 64 and
the count of the red pixels of the second ball 68, averaging out
the effects of lighting.
[0061] Identification of key golf club and body parts may begin
during the "take your stance" phase of a swing or drill. When the
student addresses the ball, the generic key part descriptors are
compared to each of the actual key part stance areas of each
incoming image. These key part areas are a function of the golfer's
height. If a sufficiently probable set of key part matches is
determined in any image, the stance position coordinates are
recognized. The actual key part descriptors are formulated and may
be saved for the student golfer.
[0062] Following recognition of stance position coordinates, the
student is commanded to "begin your swing". Each incoming image is
then scanned to locate the current swing position coordinates. The
actual key part descriptors from the last swing position
coordinates match are compared in a restricted range of the image.
The range is limited by the elapsed time since the last match and
the specific part of the swing. Less scanning range is necessary
during the back swing than the forward swing, because the club
travels faster during the forward swing, usually three times
faster.
[0063] In one example, as soon as a sufficiently probable set of
key part matches is determined in an image, the current swing
position coordinates are determined based on reference coordinates
nearest the intersection of the grip and the shaft of the student
golfer's club.
[0064] Reference Swing Position Coordinates
[0065] In one example, a reference swing position is displayed as a
translucent and outlined image of a selected virtual professional
golfer. The tracking system determines the reference swing position
coordinates and overlays the correct reference swing over the image
of the student golfer. Thus, the student golfer is provided
immediate visual feedback that compares the student golfer's swing
mechanics to the correct reference swing mechanics of the virtual
pro. The back swing arc is about 180-degrees and the forward arc is
approximately 360-degrees. For example, if the individual reference
swing positions are chosen at 18-degree radial intervals, then a
total of 36 swing position coordinates, as shown in FIG. 8, may be
displayed during a typical, full golf swing of the student golfer.
FIG. 8 helps to illustrate the notion of reference swing positions.
Twenty lines are shown, and three images are overlayed showing
three different reference swing positions, at the beginning of the
forward swing, partway through the forward swing, as wrist release
is commencing and during the follow-through at the end of the
forward swing.
[0066] In another example, a reference swing position is displayed
as a golf course scene with the outline of a selected virtual
professional golfer cut-out from the scene. This cut-out scene is
shown in FIG. 7 overlaying the student golfer's image. In FIG. 7,
the golfer is using proper golf swing mechanics, as shown by the
close fit between the golfer and the known standard showed at the
closest reference swing position.
[0067] For example, each set of reference swing position
coordinates may be associated with the correct reference swing.
Values of a reference professional golfer's wrist cock angle, swing
arc width, three-dimensional club angle of the two-dimensional
swing plane, and spine angle may be compared to the actual student
golfer's swing mechanics. For example, swing arc width may be
determined by counting the number of pixels between the center of
mass of one key body part, such as the torso or head, and another
key part, such as the glove, intersection between the grip and the
shaft or first orb of the marker attachment.
[0068] Key Parts Identifiers
[0069] Beginning at the initial stance, key part identifiers are
formed by probable matches in the image. These identifiers may be
dynamically created during the swing following each match for
current swing position coordinates. The current key part identifier
is used as the basis for subsequent comparisons.
[0070] For clubs with no special attachments, key parts identifiers
may contain image data and other information about the coordinates
of each key part, the actual pixels of the key parts, density of
the key parts, an RGB classification of the key parts, various edge
properties of the key parts, size of the key parts and rotation of
the key parts. In addition, factors that describe the way the key
parts are changing with time may be analyzed and recorded during
the swing.
[0071] Use of special colored markers may allow less sophisticated
image processing to be used to analyze golf swing mechanic values
than is required for images captured without the use of the
markers. When a marker attachment is used, the information desired
is largely the same, but the complexity in identifying the key part
identifiers is reduced, because the markers, which may be
spherically shaped orbs, are uniform and may have an
anti-reflective surface. For example, spherically-shaped orbs do
not have rotational differences or interior edges. Also, attached
markers may have a color scheme and size that makes it easy to
identify and distinguish the markers from each other and from the
background. In one example, the markers are made of a lightweight
foam material that adds little weight to the shaft and provides an
anti-reflective surface.
[0072] Real-Time Analysis
[0073] Real-time analysis allows a translucent and outlined image
of a virtual pro to be overlayed on the image of the actual,
student golfer. In one example, each successful match during the
golf swing causes the image of the virtual pro to be advanced to
the current position of the student golfer. For example, a large
number of images of virtual pro golfers may be pre-recorded, and
one may be selected for overlay on the student golfer's image
captured by the camera.
[0074] In one example, FIGS. 5A-5C illustrate the process of
updating an image displayed to the student golfer in real time,
which may also be stored for later review. The virtual pro's
overlay follows the student golfer's image captured by the camera,
while the student golfer makes a swing at the golfer's own pace
based on tracking of the student golfer's image, identification of
key parts and advancing of the reference swing position
coordinates.
[0075] Unlike previously known golf swing imaging systems, the
student golfer need not do anything different from a normal swing.
No effort or awareness by the student is necessary, and the student
can proceed at his or her own timing. The student can pause, back
track and proceed during a swing motion as the virtual professional
overlays continue to follow the golfer's own movements. This
facilitates analysis for fault-correcting interactive drills, which
are not possible with known systems.
[0076] A comparison is made between the student's key parts and
those of the virtual pro at the current swing position. In one
embodiment, the deviation limits may be predetermined by the
student's choice of skill levels. If the deviation of the student's
wrist-cock angle, swing plane angle or spine angle exceeds the
limit, a specific swing fault may be announced immediately. This
provides the ultimate interactivity for swings and drills. The
student golfer may repeatedly exercise the golf swing, making
corrections until the golf swing mechanics of the student golfer
match, within the deviation limits selected, the golf swing
mechanics of the virtual pro.
[0077] In another embodiment, a replay may follow immediately after
completion of the swing. In one example, the display hesitates at
each swing position where an error was announced, which allows the
student golfer to visualize the difference between the golfer's own
image and that of the overlay of the virtual pro.
[0078] Fix Swine Faults
[0079] The system may provide a virtual tutor for the student
golfer. For example, during or after the student golfer watches a
replay of the student golfer's swing mechanics and overlay of the
virtual pro, the shortcomings of the student golfer's golf swing
mechanics may be critiqued both visually and audibly. Then, the
program may recommend a swing mechanics drill or drills to correct
the shortcomings. In one example, the drill or drills are shown to
the student golfer in sequence, and the student golfer is given an
opportunity to practice the drills. A replay of the drill followed
by a still-view comparison of the original fault compared to the
best progress at the swing position corresponding to the fault may
be displayed. The student golfer may repeat the golf swing
mechanics analysis as many times as necessary to correct all of the
shortcomings. Then, the student golfer may change the deviation
settings to continue improvement until the student golfer closely
matches the desired golf swing mechanics of the selected virtual
pro.
[0080] Simulation of a Golf Course Setting
[0081] In another embodiment, the student's image is displayed
within the boundaries of the virtual professional's outline,
bordered by a scene such as a golf course scene. In one example,
each successful tracking match during the golf swing causes the
virtual pro's scene cut-out image of the virtual pro, as shown in
FIG. 7 to be advanced to the current position of the student
golfer. This allows the student to see his image within that of the
virtual pro as he would appear on an actual golf course. The image
may be represented on one or more than one display screens. For
example, display screens connected over a network or the internet
may be used to play a multi-player round of virtual golf with or
without the display of the virtual pro's cut-out overlay.
[0082] The virtual pro's scene cut-out overlay follows the student
golfer's image captured by the camera, while the student golfer
makes a swing at the golfer's own pace based on tracking of the
student golfer's image, identification of key parts and advancing
of the reference swing position coordinates.
[0083] A replay may follow immediately after completion of the
swing. In one example, the display hesitates at each swing position
where an error was announced, which allows the student golfer to
visualize the difference between the golfer's own image and that of
the scene cut-out overlay of the virtual pro.]
[0084] Matching the Height of the Student to the Virtual Pro
[0085] It is important for a student to match height-wise to any
selected virtual pro, both for tracking accuracy and visual
comparisons. Based upon the specified height of the student, the
student steps backward to reduce the height of his or her image or
forward to increase the height of his or her image. The image of
the virtual pro is raised or lowered accordingly, as shown in FIG.
9 to achieve height matching.
[0086] Simulated Play
[0087] In another example, the student golfer is able to play a
simulated course, including driving, woods, irons, chipping,
hitting out of bunkers and putting. The image analyzer provides
information that is not available from known launch detection
devices. Specifically, the effectiveness of launch monitors for
short putts is extremely poor, but the image analyzer predicts the
path for short putts very accurately. Also, the spin that is put on
the ball by the club face is capable of causing the ball to hook or
slice. If the club face is "closed" on contact with the ball, then
the ball will tend to hook (i.e. curve to the golfer's left). If
the club face is "open" on contact with the ball, then the ball
will tend to slice (i.e. curve to the golfer's right). This curve
depends on the spin put on the ball by rotation of the shaft during
the golfer's swing and is not accurately measured by known launch
detection devices, such as Q-Motions launch detection device.
Launch detection devices are capable of measuring the velocity of
the club head and direction of the club head on contact with the
ball. This provides an initial speed and direction to the golf
ball's trajectory. The spin on the ball, which may cause the ball
to curve during its flight in one direction or the other, is
independent of this speed and direction. The spin is important for
determining the actual course of the trajectory, as any weekend
golfer knows very well. Indeed, most professional golfers strike
the ball in a direction that is a little right of their intended
target and rely on a slight hook to curve the ball back to the
target line.
[0088] Also, if the club head precedes the grip of the club, then
the ball will tend to take a trajectory that is higher than normal
for the club selected. Ordinarily, the grip of the club slightly
precedes the club head to a line extending upwards through the
ball. However, if the grip precedes the club head by too great of a
distance, then the trajectory of the ball will be flat compared to
the trajectory that is normal for the club selected. Known launch
detection devices are not capable of determining the position of
the grip at the time of impact; therefore, the trajectory is based
only on the velocity and direction of the club head and the angle
of the club selected.
[0089] In one embodiment, the image analysis system is used to
detect the rotation of the club head and/or the position of the
grip compared to the club head, such as at the time of impact with
the ball. From the rotation of the club head, the rotation imparted
on the ball may be accurately determined. From the position of the
grip compared to the head, the divergence of the trajectory from
the norm for the club selected may be determined. This improves the
accuracy of the prediction of the actual flight of a golf ball and
provides better feedback to the golfer. A golfer is capable of
working on the golfer's hook, slice and grip location in a more
realistic setting than during drills.
[0090] In one embodiment, the image analysis system also determines
the velocity and direction of the golf head at impact with the
ball. In this embodiment, a faster frame rate is desirable in order
to have more information about the location of the key points
during the highest velocity portion of the golf swing. For example,
30 frames per second may be adequate for estimating the golf club
head velocity and direction at impact with the ball. More
preferably, a higher frame capture rate is chosen to increase the
number of reference swing positions. In one example, the image of
the student golfer is shown against the setting of the golf course.
In another example, the image of the student golfer is also
overlayed with a virtual pro image. In yet another example, the
student golfer may select to use a virtual pro's image as a sprite
in the virtual play of the game.
[0091] For example, the student golfer's image may be displayed
within the outline of a virtual pro within an imaginary or actual
golf course setting, which may be selected by the student golfer.
In one example, each successful tracking match during the golf
swing causes the virtual pro's scene cut-out image of the virtual
pro, as shown in FIG. 7, to be advanced to the current position of
the student golfer. This allows the student to see his image within
that of the virtual pro as he would appear on the course. The
virtual pro's scene cut-out overlay follows the student golfer's
image captured by the camera, while the student golfer makes a
swing at the golfer's own pace based on tracking of the student
golfer's image, identification of key parts and advancing of the
reference swing position coordinates.
[0092] In one example, the flight of the student golfer's ball is
compared to the trajectory of the virtual pro's ball. This can
clearly show the affect of improper club rotation. For example, the
trajectory of the virtual pro's ball may be shown as a colored arc,
dashed arc or otherwise highlighted trajectory, compared to the
flight of the student golfer's ball. In this example, the system
may provide audible or visual tips to the student golfer before,
during and after the swing based on the historical record
maintained on the student golfer's golf swing mechanics. For
example, the system may instruct the golfer to change the golfer's
stance, to modify a grip, to avoid flat back or any other tip that
might be provided by a live golf instructor.
[0093] One advantage of the image analysis system is that it
captures video images of the student golfer that may be replayed,
immediately after completion of the swing in order to provide a
more detailed critique of the swing and the resulting impact on the
trajectory of the golf ball. In one example, the display hesitates
at each swing position where an error was announced, which allows
the student golfer to visualize the difference between the student
golfer's own image and that of the virtual pro.
[0094] Hardware
[0095] An image recording device, such as a video camera or other
charge coupled device, may be used to record the images. It is
preferred to have a camera capturing at least 30 frames per second.
A full speed golf swing requires about 1.5 seconds of continuous
recording for an ordinary golfer; therefore, 30 frames per second
is capable of yielding about 45 images during a golf swing.
However, the rate of the swing increases as the club head
approaches an impact with the ball. In this case, the number of
images captured at 30 frames per second that are near the impact
with the ball are limited in number by the speed of the club. Also,
if the frame rate or shutter speed of the camera is too slow, then
blurring of the images of the club may make accurate estimates of
club angles difficult. A marker attachment allows for analysis of
the key points even at impact with the ball using a camera that
captures 30 frames per second.
[0096] An image should capture a full view of the student golfer
and the club through the entire arc of the swing. In one
embodiment, a wide-angle lens provides a field of view greater than
75 degrees, allowing the full view with a student golfer standing
within 6 feet of the camera. Preferably the lighting is about 80
lux or brighter, as measured with a light meter, if a marker
attachment is used. More preferably, the lighting is about 120 lux
or brighter, especially if no marker attachment is being used. The
camera system should include light balancing that eliminates glare
spots.
[0097] Preferably, the camera contains at least 640.times.480
pixels to allow for key part identification and measurements. For
example, if the camera uses a charge coupled device (CCD), then the
device may have a dimension of {fraction (1/3)} ". Higher
resolution cameras are preferred for image analysis without a
marker attachment.
[0098] It is preferred to have system memory that is capable of
storing all of the captured frames concurrently without saving to
disk. For example, if 36 positions are to be captured and
overlayed, then it is preferred to have adequate system memory to
operate the program, capture the 36 images of the golfer and
overlay the 36 images of the virtual pro. More memory is needed if
the number of the images, resolution of the images or size of the
images is increased. It is within the skill of a normal artisan to
determine the amount of memory needed to operate the system
described and claimed.
[0099] Preferably, a display device is viewable from the position
of the student golfer to provide visual feedback. A speaker or
audio device that is capable of being heard by the student golfer
may be coupled with the computer to provide audio feedback.
[0100] Preferably, the system processor and/or graphic co-processor
is capable of real-time image capture and processing. A graphics
processor may couple the computer to the display such that the
student golfer is capable of viewing the golfer's swing in real
time during the swing.
[0101] In one embodiment, the student may select a specific club,
and the system matches the known standard with the length of the
club. In another embodiment, the student golfer uses the club as
pointing to device to request the use of a specific club. Any club
may be played, including putter, wedges, irons, woods and drivers.
A database for known standards using different clubs is used to
analyze the swing mechanics at the reference position coordintes
previously described. In an alternative embodiment, the "club" may
be a short club that does not reach the ground. In this embodiment,
the marker attachment may be attached to the club or may be
integrated with the club. For example, a short club according to
this embodiment is shown in FIG. 10.
[0102] FIGS. 9A-9C illustrate one of the setup steps during setup
of the system. A student golfer may be instructed to move the
camera or the ball further apart or closer together. In one
embodiment, no measurements are required by the student golfer. For
example, the system automatically adjusts the location of the
virtual pro onto the image of the golfer. As shown in FIG. 9A, if
the golfer is too close to the camera, then the distance between
the camera and the golfer is increased, as shown in FIG. 9B. The
outline of the virtual pro does not overlay properly on the golfer
in FIG. 9B, but the system may be capable of automatically
translating the outline onto the image of the golfer, as shown in
FIG. 9C, without adjusting the camera height.
[0103] In one embodiment, a light calibration is performed to
improve lighting conditions based on the brightness and gray
properties of known color patterns of the marker attachment, for
example.
[0104] Other steps may be included in the setup and calibration of
the system for a particular users preferences. For example the
golfer may select a specific golf course to play, a specific voice
and appearance of an instructor and many other customizable
features of the system that have now become apparent to a
practitioner in the field based on the description and the examples
provided.
* * * * *