U.S. patent application number 13/933700 was filed with the patent office on 2014-01-16 for golf swing analysis method and apparatus.
The applicant listed for this patent is Zeroline Golf, LLC. Invention is credited to Steven BLAKE, Devin FITZMAURICE, Tom GIBBINGS.
Application Number | 20140018181 13/933700 |
Document ID | / |
Family ID | 49914446 |
Filed Date | 2014-01-16 |
United States Patent
Application |
20140018181 |
Kind Code |
A1 |
BLAKE; Steven ; et
al. |
January 16, 2014 |
GOLF SWING ANALYSIS METHOD AND APPARATUS
Abstract
This invention relates to a method and apparatus for analyzing a
golf swing. In particular, the invention relates to a method and
apparatus for analyzing a golf swing utilizing a portable computing
device such as a smart phone, wherein a golfer can wear the device
and the device uses sensors to monitor swing motion, and more
particularly monitor a golfer's hip mechanics during a golf
swing.
Inventors: |
BLAKE; Steven; (San Diego,
CA) ; FITZMAURICE; Devin; (San Diego, CA) ;
GIBBINGS; Tom; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Zeroline Golf, LLC |
San Diego |
CA |
US |
|
|
Family ID: |
49914446 |
Appl. No.: |
13/933700 |
Filed: |
July 2, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61668090 |
Jul 5, 2012 |
|
|
|
Current U.S.
Class: |
473/277 ;
473/409 |
Current CPC
Class: |
G16H 20/30 20180101;
G09B 19/0038 20130101; A63B 24/0006 20130101; A63B 69/36
20130101 |
Class at
Publication: |
473/277 ;
473/409 |
International
Class: |
A63B 24/00 20060101
A63B024/00; A63B 69/36 20060101 A63B069/36 |
Claims
1. A method of analyzing a golfer's swing, comprising: (a)
positioning a mobile computing device near a golfer's hips, wherein
the mobile computing device has internal accelerometers that
measure acceleration in three perpendicular axes; (b) having the
golfer take a swing at a golf ball; (c) having the mobile computing
device's microphone listen for the sound of the impact of the golf
ball and the golf club; (d) using the mobile computing device's
accelerometers and internal logic to determine: (i) a backswing hip
angle; (ii) the point in time at which the back swing hip angle is
reached; (iii) an impact hip angle taken at the time of impact of
the golf ball and the golf club as determined by the mobile
computing device's microphone; (iv) the point in time at which the
impact hip angle is reached; (v) a follow through hip angle; (vi)
the point in time at which the follow through hip angle is reached;
and (vii) hip acceleration and deceleration through the golf
swing.
2. The method of claim 1, farther comprising: (e) having the mobile
computing device's display screen display one or both of: (i) the
backswing, impact and follow through hip angles during the golf
swing; or (ii) a continuous plot of the changing hip angle through
the swing together with hip acceleration and deceleration through
the swing.
3. The method of claim 1, wherein the mobile computing device is an
iPhone.
4. The method of claim 2, further comprising: (i) having the mobile
computing device determine the tempo of the swing, wherein the
tempo of the swing is the ratio of backswing time to downswing
time; and (ii) displaying the tempo of the swing on the mobile
computing device's display screen.
5. The method of claim 2, wherein (e)(i) and (e)(ii) are
simultaneously displayed together on the display screen of the
mobile computing device.
6. The method of claim 2, further comprising: (i) having the mobile
computing device determine the point of maximum swing speed through
the swing; and (ii) displaying the point of maximum swing speed on
the mobile computing device's display screen.
7. The method of claim 2, wherein the backswing, impact, and follow
through hip angles are displayed on an animated model.
8. The method of claim 1, wherein positioning a mobile computing
device near a golfer's hips comprises placing the mobile computing
device in the user's pants pocket.
9. The method of claim 2, further comprising: (i) repeating the
method of claim 1 for a second golf swing; and (ii) displaying the
swing information as set forth in claim 2 for the first and second
golf swings simultaneously on the mobile computing device screen,
thus allowing the golfer to compare the first and second
swings.
10. A mobile computing device-based system for analyzing a golfer's
swing, comprising: (a) a mobile computing device; (b) a microphone
in the mobile computing device; (c) internal accelerometers in the
mobile computing device that measure acceleration in three
perpendicular axes; (d) a computer-based system in the mobile
computing device for using the microphone to listen for the sound
of the impact of a golf ball and a golf club; and (e) a
computer-based system in the mobile computing device for using the
accelerometers and internal logic to determine: (i) a backswing hip
angle; (ii) the point in time at which the back swing hip angle is
reached; (iii) an impact hip angle taken at the time of impact of
the golf ball and the golf club as determined by the mobile
computing device's microphone; (iv) the point in time at which the
impact hip angle is reached; (v) a follow through hip angle; (vi)
the point in time at which the follow through hip angle is reached;
and (vii) hip acceleration and deceleration through the golf
swing.
11. The system of claim 10, further comprising: (a) a
computer-based system in the smart phone for displaying one or both
of: (i) the backswing, impact and follow through hip angles during
the golf swing; or (ii) a continuous plot of the changing hip angle
through the swing together with hip acceleration and deceleration
through the swing.
12. The system of claim 10, wherein the mobile computing device is
an iPhone.
13. The system of claim 10, further comprising: (a) a
computer-based system in the mobile computing device for: (i)
determining the tempo of the swing, wherein the tempo of the swing
is the ratio of backswing time to downswing time; and (ii)
displaying the tempo of the swing on the mobile computing device's
display screen.
14. The system of claim 10, further comprising: (a) a
computer-based system in the mobile computing device for: (i)
determining the point of maximum swing speed through the swing; and
(ii) displaying the point of maximum swing speed on the mobile
computing device's display screen.
15. The system of claim 10, further comprising: (a) a
computer-based system in the mobile computing device for: (i)
recording the information as set forth in claim 10 for first and
second golf swings; and (ii) displaying the information as
described in claim 10 for the first and second golf swings
simultaneously on the mobile computing device screen, thus allowing
the golfer to compare first and second swings.
16. A mobile computing device-based system for analyzing a golfer's
swing, comprising: a. mobile computing device; b. internal
accelerometers in the mobile computing device that measure
acceleration in a plurality of axes c. a computer-based system in
the mobile computing device for using the accelerometers and
internal logic to determine an objective measure of a golf swing.
Description
RELATED APPLICATIONS
[0001] The present application claims priority to and incorporates
by reference U.S. Provisional Application No. 61/668,090 filed on
Jul. 5, 2012.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates to a method and apparatus for
analyzing a golf swing. In particular, the invention relates to a
method and apparatus for analyzing a golf swing utilizing a
portable computing device such as a smart phone, wherein a golfer
can wear the device and the device uses sensors to monitor swing
motion, and more particularly monitor a golfer's hip mechanics
during a golf swing. Of course, a person of ordinary skill in the
art will understand that the invention is not necessarily so
limited.
[0004] 2. Background of the Invention
[0005] Golf is an extremely popular sport worldwide. The popularity
stems from a variety of reasons, including the difficulty of the
game. Golfers of all levels enjoy the challenge of the game, which
requires development of both athletic ability and mental
acuity.
[0006] Improvement in golf requires some sort of a feedback
mechanism. The golfer has to have a way to evaluate whether changes
to the swing cause a positive or negative impact. Feedback can take
many forms, but any feedback system that relies solely on a
golfer's subjective evaluation of the swing is inherently flawed. A
golfer cannot see their swing, and so has no real way to be sure
what they are doing.
[0007] For this and other reasons, golf instruction is very
helpful. Not only can a professional instructor more easily spot
flaws in a golfers swing, they can visually evaluate progress
toward correction. The drawback of this approach is that the
feedback ends when the lesson ends.
[0008] Once the instruction period has ended, the golfer is
generally on their own again in terms of evaluating progress, which
of course forces the golfer to rely on mostly subjective evaluation
criteria.
[0009] Video swing analysis is similarly useful in the feedback
progress, and video systems exist that can be used to evaluate
swing mechanics in outdoor real-time environments. Modern smart
phones, and the like, can be used to photograph or take video of a
golf swing, and the player can then use the results to gauge
performance.
[0010] This approach, however, still suffers from a number of
drawbacks. It normally requires two people to utilize these
tools--one to hold and operate the device, and the other to be the
subject of the analysis. Most golfers practice by themselves and
therefore do not have the ability to easily use video. Secondly,
video is a purely visual evaluation tool, which has to be
interpreted by the golfer--thereby reintroducing subjectivity into
the process. Video allows the golfer to see what they are doing,
but it does not necessarily help them understand what they are
doing. In other words, it is one thing to see something it is
entirely another thing to appreciate the significance of what you
are seeing.
[0011] Video does not provide objective feedback, because the
results still need to be subjectively evaluated. The feedback loop
has still not been closed.
[0012] Accordingly, a need exists for an improved apparatus and
method to provide a golfer with an objective means to evaluate
their golf swing.
SUMMARY OF THE INVENTION
[0013] An object of the present invention is to provide an improved
apparatus and method for a golfer to objectively evaluate their
golf swing.
[0014] These and other objects of the present invention will become
apparent to those skilled in the art upon reference to the
following specification, drawings, and claims. To that end, the
present invention comprises a method and apparatus read the break
in a surface and adjust aim accordingly. The method utilizes a
mobile computing device positioned near a golfer's hips, wherein
the mobile computing device has internal accelerometers that
measure acceleration in three perpendicular axes. The golfer takes
a swing at a golf ball. The mobile computing device's microphone
listens for the sound of the impact of the golf ball and the golf
club. The mobile computing device's accelerometers and internal
logic to determine one or more of the following: a backswing hip
angle; the point in time at which the back swing hip angle is
reached; an impact hip angle taken at the time of impact of the
golf ball; and the golf club as determined by the mobile computing
device's microphone; the point in time at which the impact hip
angle is reached; a follow through hip angle; the point in time at
which the follow through hip angle is reached; and hip acceleration
and deceleration through the golf swing.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 shows a swing list screen shot.
[0016] FIG. 2 shows a swing animation screen shot.
[0017] FIG. 3 shows a swing chart and graph screen shot.
[0018] FIG. 4 shows a swing animation and comparison screen
shot.
[0019] FIG. 5 shows a swing chart and graph comparison screen
shot.
[0020] FIG. 6 shows a decision model block diagram
[0021] FIG. 7 shows an axis motion diagram.
[0022] FIG. 8 shows composite view of a golf swing.
[0023] FIG. 9 shows an address detection algorithm.
[0024] FIG. 10 shows a backswing detection algorithm.
[0025] FIG. 11 shows a swing disqualification check diagram.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] In the Figures, is shown a mobile device application that
measures a golfer's hip mechanics during a golf swing to provide
precise and relevant information back to the golfer. In particular,
the device is a smart phone and more particular a smart phone
running the Apple OS or Android operating system, or other similar
systems and related devices. Of course, the invention is not
necessarily so limited.
[0027] The swing analysis and resulting feedback and metrics
information substantially overcomes the limitations of prior art
device applications that rely on video or detached wireless sensors
to record swing motion because of the following advantages: [0028]
The present invention determines the impact point of the club and
ball via sound detection using the device microphone. Specifically,
the following swing metrics are dependent on measuring the point of
ball impact: [0029] Impact hip angle [0030] Tempo [0031] Hip
acceleration and deceleration [0032] Lateral motion [0033] Real
time swing recognition is continuous requiring no prompts or
countdown sequences to tell a golfer when to swing. [0034] Address
position can change to allow the golfer to aim at various targets
without affecting alignment, resulting turn angle metrics, or
requiring any manipulation of the device. [0035] Only valid swings
that meet motion, timing, impact, and acceleration rules are
recorded, and validity is determined by the device. [0036] Uses
device hardware capabilities of sound, vibration, and visual
display to provide immediate feedback for each recorded swing.
[0037] Uses the mobile device motion sensors and gyroscope to
measure the following aspects of a golf swing: [0038] Back swing
turn hip angle [0039] Ball impact hip angle [0040] Follow through
hip angle [0041] Max hip speed [0042] Tempo: ratio of timing from
start to top and top to impact [0043] Hip angular velocity [0044]
Hip acceleration and deceleration [0045] Lateral motion [0046] Tilt
[0047] Analysis of recorded swings is presented through three
different visual displays using bright color contrasts to be
visible outdoors [0048] Swing Animation--The swing animation
displays the 3 hip angles listed above through an animated model.
[0049] Swing Graph--The graph displays hip speed over time and
reveals hip angular acceleration and deceleration, timing at top,
impact, and finish, and the top speed point during the swing [0050]
Swing List--This resembles a spreadsheet by listing the data
associated with multiple swings to allow a user to quickly compare
the numbers. The swing list is a mechanism to determine consistency
and identify outliers. [0051] Provides meaningful objective metrics
and measurements for golfers of all skill levels. [0052] Support
for rapid experimentation of different hip motions and tempo and
their resulting affect on shot shape (straight, fade, draw, push,
pull, slice, hook). [0053] Allows golfer to save swings to a
Favorites list and using these swings for future reference. [0054]
Allows golfer to save a swing as a Baseline for use as a future
comparison to other swings. The ability to save swing metrics for
good and bad shots is key to the golfer's ability to later adjust
hip mechanics to achieve desired results. [0055] Tag recorded
swings with descriptions, club selection, swing type, and shot
shape. The following describes the operation of the device software
in performing various tasks. [0056] Recording Swings Recording
Swings is achieved by: 1. Pressing the record button to begin
motion sensor sampling and start the swing recognition algorithm.
2. Placing the device firmly and securely on or near the hips
[0057] a. In a front or back pocket [0058] b. By tucking it between
the pant waistband or belt and the waist [0059] c. In a holder that
clips on the pant waistband or belt [0060] d. Using a waist strap
designed to hold the device 3. Taking one or more swings
[0061] Device holders that clip on a belt and straps that go around
a waist are generally available from a number of retailers. [0062]
Analysis and Resulting Feedback
[0063] Each recorded swing can be analyzed through the application
views that show a swing list spreadsheet, an animation, a chart and
graph, and in comparison to another recorded swing used as a
baseline. The swing list view is depicted in FIG. 1. This view
allows the golfer to view the analytic information in a list. The
view shows a previously captured baseline swing displaying (from
left to right) the back swing hip angle, impact hip angle, follow
through hip angle, tempo ratio, and maximum hip speed in degrees
per second. Also, displayed are comments included a tagline ("Nice
1"), swing type ("Full"), and club ("Driver").
[0064] Below the baseline entry is the same information for three
recorded swings, which can be easily viewed in comparison to the
baseline swing analytics. The list view also allows you to view any
favorite swings that have been stored in the system. At the bottom
of the screen, options are available to clear the entries, record
new swings, post the information to email or social media, and an
information icon.
[0065] FIG. 2 shows the swing animation view for any particular
view selected by the golfer. This view shows a 360.degree. top down
view of the golfer to view an animation of the swing from start to
finish. The view also shows a two dimensional graph of the swing
where the x-axis represents time, and the y-axis hip rotation angle
(0.degree. line represents the address position, negative angles
represent the back swing and the beginning portion of the down
swing, and positive angles represent the remainder of the down
swing and follow through). In FIG. 2, the back swing hip angle is
shown ("-46.degree."), the impact hip angle ("23.degree."), follow
through hip angle ("68.degree."), and the hip angle at the point of
maximum hip speed ("3.degree."). The impact point is shown with the
dotted line.
[0066] FIG. 3 shows the swing chart and graph view, which in
addition to the information shown in the other views shows the with
the additional graph line the acceleration and deceleration
profile, as well as the points in time acceleration and
deceleration peak.
[0067] FIG. 4 show the swing animation comparison screen, which
allows the golfer to select two swings to compare in the animation
view.
[0068] When a swing is animated, the primary animation is played in
parallel with the swing graph. The purpose is to align the two
aspects of the data to enable a user to properly analyze a swing.
The graph animation is important because it reveals the point of
hip stabilization and deceleration where kinetic energy is
transferred from the hips to the upper torso and arms, which
ultimately effects club head speed. This transfer of energy
represents provides great insight into a user's ability to generate
swing power.
[0069] The golf coach can use the application during the lesson to
identify and tag a baseline swing. This allows the coach to
prescribe motion and the type of practice that a student should be
doing. A coach would want to save both a student's best shot to
aspire to and poor shots that exemplify common pitfalls and errors.
Identifying both good and bad shots will enable the student to
recognize what types of movements impact the quality of the shot
during practice.
[0070] FIG. 5 shows the swing chart and graph comparison, which
compares two swings using the chart view format.
[0071] The present invention supports the use of social media. Once
a golfer has constructed a list of swings, he has the ability email
or post the swings on Facebook natively in the application through
a button click (see the rectangle/arrow icon at the bottom right of
FIGS. 1-5). There are two different things that a user can post--an
individual swing animation, and the swing list. The place that
these elements are posted will vary based on whether the golfer has
identified a coach. If a coach has not been identified, the element
will be posted on the user's Facebook wall. If a coach has been
identified, the element will be posted on the coach's wall. In both
circumstances, the user will be tagged in the swing to ensure it
shows up in various news feeds for others to see. This aspect
benefits both the golfer and the golf coach, by further closing the
feedback loop.
[0072] For the golfer, posting an element on Facebook is the
primary mechanism in which to close the feedback loop with the golf
coach between lessons. When a new golfer is going through a series
of lessons to improve swing mechanics, the golfer will typically
see an initial degradation in consistency, which results in
frustration. During this phase of retooling swing mechanics, it is
critically important to keep the new golfer actively engaged with
the golf coach to ensure proper practice techniques and the
likelihood of the golfer returning for another lesson, and to
prevent the golfer from misinterpreting the negative results and
making unrelated changes that compound the problems. Both win in
this scenario because the golfer has increased odds of improving
their swing mechanics, and the golf coach is awarded with continued
business. Not only can a user post swings on Facebook but they can
also be emailed to a coach as well.
[0073] There is also an embedded feature inside the application
that enables a user to seek out certified instructors from a list
provided from a competent source. If a user is having problems with
his swing, there will be a button inside the application that
enables a user to send the swing to a nearby certified coach for
analysis. A coach who is trying to develop additional business can
then elect to respond to a request as a new business development
mechanism. Certified instructors are searchable in the application
and associated to the user account as their instructor. This
enables easy posting of swings to the coach's Facebook wall. When
posted, the swing will show the coaches name in the animation/swing
fingerprint picture. When a swing is posted to a coach's wall, the
user will be automatically tagged in the swing to get the swing to
show up in the user's newsfeed.
[0074] Accompanying the application are education resources to aid
a user with the journey of swing improvements. An important topic
is, a "now what?" feature. It is one thing when a trained golf
professional is using the application to walk a user through the
interpretation of the data; it is another thing to draw a user into
the application without the presence of a golf professional. When a
first time user uses the application, they will need assistance in
understanding and applying the information provided, therefore, it
will be important to guide them through what to do next. The first
step toward this end is intuitive design; the next step is
education resources. This all is designed to convert the
application objective analytical data into the golfers' personal
swing knowledge. In FIG. 6, is a practice and decision model that
will translate the data to an actionable practice method.
[0075] Another benefit of the present invention is its ability to
objectively and automatically perform swing recognition, through in
particular the use of device hardware. The swing recognition
algorithm makes use of mobile device hardware including the motion
sensor and accelerometer, the system clock and its timer
capabilities, and the system audio microphone and speaker
components.
[0076] As shown in FIG. 7, the swing recognition algorithm uses the
motion sensor to obtain 3-axis motion data that includes [0077]
Pitch--rotation around the X axis [0078] Roll--rotation around the
Y axis [0079] Yaw--rotation around the Z axis
[0080] These angles are also known as Euler angles and each
represents degrees of rotation around an axis. From a selected
reference angle set, subsequent angle data defines the number of
degrees and direction the device has moved along each axis.
[0081] The swing recognition algorithm detects the impact point
using the device microphone and sampling for a spike in peak
volume. The recognizer must be able to choose the correct impact
point from multiple possible sounds from various sources such as
other golfers hitting balls nearby, a loud voice, or a car horn in
the background.
[0082] The device speaker is used to signal the successful swing
recognition to the golfer by playing a short sound like a beep or
ping.
[0083] When the device is secured to a golfer's hip, motion changes
are sampled up to 60 times per second by accessing the system clock
a timer components. As the hips turn and tilt during a golf swing,
the motion data is used to detect the following distinct motion
segments of a golf swing (all described in reference to the panels
shown in FIG. 8):
[0084] 1. A swing always starts with an address position during
which motion is still or minimal (FIG. 8 panel #1)
[0085] 2. The backswing starts with a backward turn motion that
continues its direction until the top or transition point at the
start of the down swing. Turn speed and acceleration during the
backswing segment are relatively slow compared with speed and
acceleration of the downswing. (FIG. 8 panel #5)
[0086] 3. The downswing is the start of forward motion from the top
of the backswing. Turn speed and acceleration increase rapidly.
Impact of the club head with the golf ball happens during the
downswing, normally just after the hips pass their position at
address. (FIG. 8 panel #9)
[0087] 4. The swing finish is a continuation of the downswing past
impact. Turn speed and acceleration slow from their downswing peak.
At the finish, motion is still or minimal. (FIG. 8 panel #12)
[0088] Swing recognition by the application relies on key device
hardware components available on most presently available smart
phones, as well as other similarly enabled computing devices such
as small tablet computers.
[0089] The swing recognition algorithm samples motion data from the
device up to 60 times per second. For each timer interval, the new
motion data is compared to the last data. The changes, or deltas,
in degrees and direction around each axis can determine the motion
direction, speed, acceleration, tilt, and sway, which allows for
identification of swing segments.
[0090] The application makes defines reference angles to allow for
detection of swing segments. From a selected reference angle set,
subsequent angle data defines the number of degrees and direction
the device has moved along each axis. The swing algorithm sets
reference angles at the start of the motion sampling. During swing
recognition, reference angles are reset frequently when periods of
still motion are detected.
[0091] The motion data must be modified depending on the device
orientation. The swing recognizer works properly regardless of
orientation. The device can be in portrait mode with it top up or
down. It can also be in landscape mode on its right or left side.
The recognizer does not work when the device is face up or face
down.
[0092] In portrait orientations, the recognizer uses the Y axis
roll angles to track motion. With the device on either side in
landscape orientation, the recognizer uses the X axis pitch
angles.
[0093] FIG. 9 depicts a flow diagram for the address segment of the
swing. A swing always starts with an address position during which
motion is still or minimal. The golfer can change alignment to a
target without affect on the algorithm or the resulting swing
metric data. This is possible because the algorithm resets the
reference angles whenever a sequence of still motion samples are
detected. Movements in either direction, forward or backward, are
determined to be still if the change of motion is less than a
threshold of about 0.5 degrees. About 25 continuous still motion
samplings will cause a reset of the reference angles. The number of
still motions and the threshold are configurable, and can be varied
based on experimentation.
[0094] The golf swing is considered to be in the address segment
whenever continuous motion sampling is still or the reference
angles have just been reset. The exception is if still motion is
showing contiguous movements in the same direction, this is
purposeful motion as opposed to random motion, which changes
direction in no discernable pattern. Purposeful motion is allowed
to continue past the still motion threshold and the angles are not
reset. This allows the swing recognizer to accurately calculate the
start of the backswing segment.
[0095] The Backswing Segment flow diagram is shown in FIG. 10. The
backswing starts with a backward turn motion that continues its
direction until the top or transition point at the start of the
down swing. Turn speed and acceleration during the backswing
segment are relatively slow compared with speed and acceleration of
the downswing.
[0096] Every motion sample during each timer interval is tested for
direction. Backswing direction is opposite for left or right-handed
swings. The swing recognizer determines left or right swings by the
direction of the backswing segment indicated by positive or
negative angle data from the motion sensor. The backswing segment
directional recognition algorithm is the same for either backward
or forward direction.
[0097] If the direction is the same as the previous motion sample
then the directional continuity counter is incremented. A valid
backswing segment will have a minimum number of continuous
directional motions. The directional continuity minimum threshold
is tested. There must also be purposeful continuous motion that has
minimal still motion samplings. Too much still motion will cause a
reset of the reference angles, which stops the current swing
recognition and starts it over from the beginning. Directional
movement that reaches the minimum continuity threshold with
purposeful motion qualifies as a backswing segment. Turn speed,
direction change counts, maximum speed, segment time, and total
turn angles are among the metrics variables tracked.
[0098] Once the backswing segment is valid, further backward
motions add to its length. Subsequent forward motions do not
invalidate the backswing segment. This allows for some sway at the
top of the backswing.
[0099] If the direction has changed, directions from the previous
forward motion sample:
[0100] 1. A possible swing finish is determined it both a valid
backswing and downswing (forward swing) segments.
[0101] 2. A new backswing start is begun if preceding backward
motions did not establish a valid backswing segment.
[0102] Variables that track directional continuity, possible finish
segment position, new backswing segment start, speed, angles, tilt,
sway, and time are all updated.
[0103] A valid backswing segment can become invalid if its
continuity is too long so a check is performed to see if the
continuity is below the maximum.
[0104] Another step in the process is the swing qualification
processing, which is valid for the back swing and the down swing
segments. Every motion sample is also tested for the existence of
both a valid backward and forward segment; the two key motion
segments that form the swing. Once these are in place, a short
series of backward motions that are still (movement below the still
motion threshold), constitute the swing finish segment. At this
point, with all four swing segments identified, the swing is
qualified and the algorithm proceeds to a series of checks that
might yet disqualify it. These checks are described below in the
Swing Recognition Disqualifiers section (also shown in FIG.
11).
[0105] The down swing segment is not described. The downswing is
the start of forward motion from the top of the backswing. Turn
speed and acceleration increase rapidly. Impact of the club head
with the golf ball happens during the downswing, normally just
after the hips pass their original position at address.
[0106] The recognition algorithm for Motion Direction Processing as
well as Swing Qualification Processing for the downswing segment is
identical to that of the backswing segment. The motion data can
start in either direction depending on the golfer swinging right or
left handed. The right-handed backswing motion data is the same
direction as the left-handed downswing, and vice versa. Refer to
The Backswing Segment section for the algorithm.
[0107] The downswing segment must have one important attribute not
present in the backswing segment: an impact point when the club
hits the golf ball. This processing is described in the next
section.
[0108] The swing recognition algorithm detects all possible impact
points using the device microphone and sampling for a spike in peak
volume. The recognizer must be able to choose the correct impact
point from multiple possible sounds from various sources such as
other golfers hitting balls nearby, a loud voice, or a car horn in
the background.
[0109] The microphone is sampled up to four times during each
motion sampling. At 60 motion samplings per second and 4 sound
samplings per motion, the sound level is checked up to 240 times
per second. This is important to ensure accuracy of the impact
point since it is key to determining the impact hip turn angle, the
impact timing and swing tempo, and deceleration at impact.
[0110] Impact points are analyzed and validated during the motion
sampling. Impact points during the address, backswing, and finish
segments are not valid. Only impact points that occur during the
downswing segment are valid. All valid impact points are saved in
an array. Placement position in the array is done so that the most
qualified and likely impact point is in the array's first position.
Placement is determined by these factors:
[0111] 1. A new impact point does not replace an existing point if
it is within four motion sampling intervals of the existing point.
The sound of an impact can register a peak sound level over several
motion samples.
[0112] 2. If the peak sound (loudness) of a new impact point is
greater than an existing point, the new point can replace the
existing point.
[0113] 3. If a new impact point is in a valid expected hip turn
range of 10 to 40 degrees, the new point can replace an existing
point that is not in the expected range.
[0114] The finish segment is now described. The swing finish is a
continuation of the downswing past impact. Turn speed and
acceleration slow from their downswing peak. At the finish, motion
is still or minimal. The finish segment begins when the downswing
segment reaches its end and changes direction or becomes still for
a short series of motion sampling intervals, around eight such
intervals. This allows for either a smooth finish that just slows
to a stop or a finish that slows but then quickly changes direction
into a recoiling motion.
[0115] Detection of the finish segment ensures only that all four
swing segments have been identified. The swing is qualified such
that is has motion that forms the four segments. However, motion
alone does not determine a valid swing. For example, a swing in
very slow motion can produce the four motion segments, but it would
lack sufficient speed, acceleration, and timing to be recognized as
a valid swing. Additionally, a practice swing might otherwise
qualify, but it lack impact.
[0116] To achieve qualification as a valid swing, the algorithm
proceeds to a series of checks that might disqualify it. These
checks are described below.
[0117] Once all four swing segments have been identified, the swing
recognizer makes a series of tests that all valid golf swings must
pass. Failure of any one of these tests disqualifies the potential
swing and restarts the swing recognition algorithm to the start.
Each disqualification test is described below (see also FIG.
11).
[0118] 1. Did the swing achieve the minimum required speed? This
rules out very slow motion swings that had no real speed or
significant acceleration. This also eliminates random motion the
golfer might make between swings.
[0119] 2. Did the swing achieve the minimum required turn angle? A
valid swing must have a backward turn then a forward turn. The sum
of these turns must be a minimum number of degrees. This rules out
small swings like chips or putts, or just random motion between
swings; waggles, half turns, and small back and forth motions.
[0120] 3. Did the device orientation stay consistent during the
swing? The orientation when the reference angles are set must stay
the same through the swing finish. Otherwise, motion data angles
for pitch and roll may be confused.
[0121] 4. Did the swing complete within a time limit? Most golf
swings take about 2 seconds from start to finish. Any time more
than 4.5 seconds indicates random motion that could be going on
after the four motion segments have been completed.
[0122] 5. Did the swing contain at least one impact point? A valid
swing without impact is just a practice swing.
[0123] 6. Did the backswing turn and downswing turn both complete
within their turn limits?
[0124] A real golf swing has normal and reasonable turns in both
directions. Excessive turns, full circles, and other wild turn
movement disqualify the swing.
[0125] 7. Did the downswing pass or cross the position at address?
A valid swing must turn back then forward past the address position
facing the ball.
[0126] 8. Did the swing achieve top speed during the downswing? Top
speed is normally just before or after impact. A swing that has its
top speed during the backswing is not a real golf swing.
[0127] A valid swing that has passed all the disqualification tests
is ready to be processed as a real recorded swing. Steps to create
the recorded swing follow. [0128] Recording is suspended while the
swing is created and saved. This stops the motion sensor time
interval samplings and analysis. [0129] The golfer is notified that
a swing has been recorded via sound and vibration. [0130] A golf
swing object is created [0131] The reference angle data and all
other motion data points that construct the swing motion segments
are transferred from an internal buffer to an array property of the
golf swing object. Each data point contains the Euler angles for
pitch, roll, and yaw, a timestamp, speed or roll motion, and
indication of whether the data point is before or after impact.
[0132] Speed values of each data point are adjusted based on actual
time rather than the timer interval constant, since the system does
not always invoked the timer on exact timer intervals. Devices such
as smart phones are not dedicated real-time devices and are subject
to interruptions and delays from other applications running in the
background. Phone calls and other types of alerts also affect the
timer interval. [0133] The impact angle is adjusted two ways:
[0134] To allow for the time variance for the sound to travel from
the club and ball to the device. This reduces the impact angle
slightly. [0135] To allow for which of the four sound samplings
taken during the impact motion sensor interval actually recorded
the impact. These happen at different times during the interval.
This reduces the impact angle slightly if the first sound sample
found impact, and increases the impact angle slightly if the
2.sup.nd, 3.sup.rd, or 4.sup.th sound sample detected the impact.
[0136] The swing is saved with the golfer's profile and written to
the disk. [0137] Recording is resumed which begins the motion
sensor time interval samplings and analysis.
[0138] The swing recognition algorithm resets the reference angles
and begins analyzing motion samples to define address, backswing,
downswing, and finish segments for the next swing.
[0139] Features in the application offer the student multiple
options when capturing and analyzing data at any point in the
learning process. For example if a student is a beginner or a
scratch golfer, learning a new motor skill, there are specific
functions built in to the application to guide efficient learning
and practice. There are also different modes that give feedback
based on learning styles and preferences. The animation mode gives
the student multiple layers of data using color and design. The
data is displayed with an animated diagram that can be slowed or
paused to analyze any element in the swing. Data like speed,
acceleration, deceleration, rotation, tempo, hip angles a can be
compared against other swings in multiple formats in a side-by-side
mode. The chart mode shows the data in an animated graph format.
The spreadsheet mode not only shows hip data it can also display
pattern recognition, timestamps, notes, tags and give an efficiency
rating for most of the data. Each mode will serve a specific
purpose for the user depending on their individual intentions. When
a student is practicing a new motor skill and is using repetition
to train the skill using the spreadsheet mode will give the best
feedback at a glance. When a student is just looking for feedback
on a specific swing or metric that animated modes will offer just
the right amount of feedback. The animated mode is good for a small
number of swings in a tight feedback loop and the spreadsheet mode
is good for a large number of repetitive swings with a broad range
of feedback.
[0140] The info menu offers access to videos, articles, and
diagrams to explain or troubleshoot any details that may need to be
understood by the user. The videos are in a storytelling structure
so the user can build the best possible memories to assist in the
experience. The graphic animations, charts, graphs and the layout
of the user interface have been design to offer multiple levels of
information displayed in a very intuitive manner so the student can
focus on what is relevant for their learning and not get distracted
with unnecessary feedback.
[0141] The invention has been described in reference to golf, but
it is not so limited. In particular, the invention can be applied
to motion analysis for other sports. With modifications to the
definition of motion segments and disqualification rules, the swing
can be used to detect key movements in other sports and activities,
such as: [0142] The tennis serve has address, backward, forward and
finish segments, and impact of the racket with the ball. Hip action
plays an important part in the power and flight of the serve.
[0143] The baseball and softball swing has address, slight
backward, forward and finish segments, and impact of the bat with
the ball. Hip action plays an important part in the power and
flight of the ball. [0144] The hockey slap shot has address,
backward, forward and finish segments, and impact of the stick with
the puck. Hip action plays an important part in the power and
flight of the shot. [0145] Football punting and placekicking both
have address, backward, forward and finish segments, and impact of
the foot with the ball. Hip action plays an important part in the
power and flight of the ball. [0146] Soccer has address, backward,
forward and finish segments, and impact of the foot with the ball.
Hip action plays an important part in the power and flight of the
ball. [0147] Martial arts, boxing, punching, kicking actions all
involve sequencing of the hips to produce power. These actions can
be recognized with the golf swing recognizer. [0148] Fitness,
training, cross fit, and gymnastic activities all have motion that
requires proper turns, flexibility, stabilization, and other
movements that can be detected and monitored with recognition
algorithms similar the golf swing recognizer.
[0149] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
methods and materials similar to or equivalent to those described
herein can be used in the practice or testing of the present
invention, suitable methods, and materials are described below. All
publications, patent applications, patents, and other references
mentioned herein are incorporated by reference in their entirety to
the extent allowed by applicable law and regulations. In case of
conflict, the present specification, including definitions, will
control.
[0150] The present invention may be embodied in other specific
forms without departing from the spirit or essential attributes
thereof, and it is therefore desired that the present embodiment be
considered in all respects as illustrative and not restrictive,
reference being made to the appended claims rather than to the
foregoing description to indicate the scope of the invention. Those
of ordinary skill in the art that have the disclosure before them
will be able to make modifications and variations therein without
departing from the scope of the invention.
* * * * *