U.S. patent application number 13/556027 was filed with the patent office on 2014-01-23 for golf analysis system with frameless optical sensor net.
This patent application is currently assigned to Focaltron Corporation. The applicant listed for this patent is James Pao, Yi-Ching Pao. Invention is credited to James Pao, Yi-Ching Pao.
Application Number | 20140024470 13/556027 |
Document ID | / |
Family ID | 49947010 |
Filed Date | 2014-01-23 |
United States Patent
Application |
20140024470 |
Kind Code |
A1 |
Pao; James ; et al. |
January 23, 2014 |
GOLF ANALYSIS SYSTEM WITH FRAMELESS OPTICAL SENSOR NET
Abstract
A golf analysis system includes a light emitter assembly,
including first and second light emitters spaced apart from one
another, and a light detector assembly, including first and second
sets of light detectors arranged along a surface of a practice area
beneath the light emitters. The light emitters emit first and
second spreads of non-parallel light rays, received by the light
detectors, to form an optical sensor net for capturing relational
kinetic information when at least one of a golf ball and a golf
club passing through the optical sensor net. The region between the
level of the light detectors and the level of the light emitters is
substantially free of mechanical structure.
Inventors: |
Pao; James; (Los Altos
Hills, CA) ; Pao; Yi-Ching; (Los Altos Hills,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Pao; James
Pao; Yi-Ching |
Los Altos Hills
Los Altos Hills |
CA
CA |
US
US |
|
|
Assignee: |
Focaltron Corporation
Sunnyvale
CA
|
Family ID: |
49947010 |
Appl. No.: |
13/556027 |
Filed: |
July 23, 2012 |
Current U.S.
Class: |
473/220 ;
473/409 |
Current CPC
Class: |
A63B 2220/805 20130101;
A63B 69/3623 20130101; A63B 69/3614 20130101; A63B 71/0619
20130101 |
Class at
Publication: |
473/220 ;
473/409 |
International
Class: |
A63B 69/36 20060101
A63B069/36 |
Claims
1. A golf analysis system comprising: a light emitter assembly
comprising first and second light emitters spaced apart from one
another by first distance; a light detector assembly comprising
first and second sets of light detectors arranged at a first level
along a surface of a practice area, the practice area comprising a
tee region and an intended golf ball path extending from a chosen
tee location within the tee region; the first and second sets of
light detectors positioned opposite one another and oriented
transversely to the intended golf ball path; the first and second
light emitters capable of emitting first and second spreads of
non-parallel light rays to be received by the first and second sets
of light detectors, respectively; the first and second light
emitters located at a second level vertically above the practice
area by at least a second distance; the first and second spreads of
non-parallel light rays forming an optical sensor net to permit
capturing relational kinetic information of at least one of a golf
ball and a golf club during a golf club swinging motion on the
practice area when said at least one of the golf ball and golf club
passes through at least a portion of the optical sensor net; and
the region above the first level and below the second level being
substantially free of mechanical structure to prevent inadvertent
contact between a golf ball or a golf club and such mechanical
structure during the golf club swinging motion.
2. The golf analysis system according to claim 1, wherein the first
and second light emitters emit laser light.
3. The golf analysis system according to claim 1, wherein each of
the first and second spread of non-parallel light rays extend
downwardly toward the first and second sets of light detectors at
angles of about 5.degree. to 15.degree. from vertical.
4. The golf analysis system according to claim 1, wherein the first
and second light emitters are located at positions vertically above
locations situated between the first and second sets of light
detectors and the tee region.
5. The golf analysis system according to claim 1, wherein each of
the first and second sets of light detectors comprise individual
light detectors separated by distances that are less than the
minimum radius of a typical golf ball of about 0.8 inch.
6. The golf analysis system according to claim 1, wherein the first
and second sets of light detectors define a cross sectional
ball/clubhead detection area with a first width and a first height
of the optical sensor net.
7. The golf analysis system according to claim 6, wherein said
detection area is about 2 to 4 feet in both width and height.
8. The golf analysis system according to claim 1, wherein the first
and second sets of light detectors are oriented generally
perpendicular to and generally centered on a plane extending
vertically or tilted vertically at about 5 to 10 degrees downwardly
from the intended golf ball path.
9. The golf analysis system according to claim 1, wherein the
second distance is at least about 9 feet.
10. The golf analysis system according to claim 1, comprising first
and second light emitter assemblies and first and second light
detector assemblies defining first and second optical sensor nets,
said first and second optical sensor nets being spaced apart from
one another.
11. The golf analysis system according to claim 10, wherein the
first and second optical sensor nets are oriented generally
parallel to one another.
12. The golf analysis system according to claim 10, wherein the
first and second light detector assemblies are oriented generally
perpendicular to and generally centered on the intended golf ball
path.
13. The golf analysis system according to claim 10, wherein: the
first and second sets of light detectors of the first light
detector assembly define a cross sectional area with a first width
and a first height; the first and second light detector assemblies
being separated by a distance of about 100% of the first width.
14. The golf analysis system according to claim 1, wherein the
light emitters and detectors are capable of providing information
to a data processor.
15. The golf analysis system according to claim 1, further
comprising visual display to display data generated by the data
processor from the movement of the golf ball through the optical
sensor net.
16. The golf analysis system according to claim 1, further
comprising a catching net placed along the golf ball intended
path.
17. A method for enabling the determination of dynamic spatial
information for a golf practice swing using a golf analysis system
comprising an optical sensor net, the method comprising: taking a
golf practice swing at the tee region of a practice area of the
golf analysis system with or without hitting a golf ball along an
intended golf ball path; passing at least one of a golf club head
and a golf ball hit by the golf club along a golf ball/club path
through an optical sensor net; emitting, by the optical sensor net,
first and second spreads of non-parallel light rays downwardly from
first and second light emitters of a light emitter assembly, the
first and second light emitters spaced apart from one another by a
first distance and located vertically above the practice area by at
least a second distance; receiving, by the optical sensor net, the
first and second spreads of non-parallel light rays by first and
second sets of light detectors of a light detector assembly,
respectively, the first and second sets of light detectors arranged
along a surface of the practice area, each set of light detectors
comprising a plurality of detector elements; interrupting at least
two of said non-parallel light rays by said at least one of the
golf club head and the golf ball; and eliminating substantially all
mechanical structures above and nearby the practice area between
the level of the practice area and the level of the first and
second light emitters thereby preventing inadvertent contact
between the golf ball or the golf club and such mechanical
structures during the practice swing.
18. The method according to claim 17, further comprising:
identifying light detector elements that receive interrupted
non-parallel light rays as a result of the practice golf swing;
measuring interruption times for the identified detector elements
that detect the interrupted non-parallel light rays; and
determining dynamic spatial information for the golf club practice
swing based on the measured interruption times for the selected
light detectors that receive interrupted non-parallel rays of
light; and the identifying, measuring and determining steps carried
out using information supplied by at least the light detector
assembly providing data to a data processor.
19. The method according to claim 18, further comprising: placing a
golf ball at a tee location within the tee region; determining the
location of the tee location relative to the optical sensor net;
and providing tee location information to the data processor.
20. The method according to claim 18, further comprising: placing a
golf ball at a tee location within the tee region; wherein the
passing step comprises passing the golf ball through first and
second optical sensor nets, the optical sensor nets spaced apart
from one another at first and second positions along the intended
golf ball path, the use of the first and second spaced apart
optical sensor nets eliminating a need to provide the tee location
information to the data processor.
21. Given an undetermined tee location, a method for providing
dynamic spatial information with an optical sensor net for a golf
practice swing comprising the steps of: selecting a sensor system
including a divergent light source for emitting at least two
non-parallel rays of light towards an array of light detectors to
form an optical sensor net; passing the golf ball through the
non-parallel rays of light within the optical sensor net to
interrupt emission of the rays of light to the array of light
detectors; identifying selected light detectors that receive
interrupted rays of light emitted by the divergent light source
caused by the golf ball passing through the optical sensor net;
detecting interruption times for the selected detectors within the
array of light detectors that detect interrupted rays of light;
measuring dynamic spatial information for the golf ball based on
the detected interruption times for the selected light detectors
that receive interrupted non-parallel rays of light; identifying
second, third, and fourth groups of selected light detectors that
receive interrupted rays of light emitted by the divergent light
source caused by the golf ball passing through the optical sensor
net; detecting interruption times for the second, third, and fourth
groups of selected detectors within the array of light detectors
that detect interrupted rays of light; and computing dynamic
spatial information for the golf ball based on the measured
interruption times for the selected light detectors that receive
interrupted non-parallel rays of light.
22. The method for providing dynamic spatial information as recited
in claim 21, further comprising: passing a golf club through the
optical sensor net through the non-parallel rays of light within
the optical sensor net to interrupt emission of the rays of light
to the array of light detectors; identifying a second group of
selected light detectors that receive interrupted rays of light
emitted by the divergent light source caused by the golf club
passing through the optical sensor net; detecting interruption
times for the second group of selected detectors within the array
of light detectors that detects interrupted rays of light; and
computing dynamic spatial information for the golf club based on
the measured interruption time for the selected light detectors
that receive interrupted non-parallel rays of light.
23. The method for providing dynamic spatial information as recited
in claim 21, wherein the dynamic spatial information includes golf
ball speed and trajectory.
24. The method for providing dynamic spatial information as recited
in claim 21, wherein the dynamic spatial information includes club
speed information and club swing path information.
25. Given an undetermined tee location, a method for providing
dynamic spatial information with an optical sensor net for a golf
practice swing comprising the steps of: selecting a sensor system
including first and second divergent light sources for emitting at
least two non-parallel rays of light from each divergent light
source towards first and second arrays of light detectors to form
first and second optical sensor nets; passing the golf ball through
the non-parallel rays of light within the optical sensor net to
interrupt emission of the rays of light to the first and second
arrays of light detectors; identifying selected light detectors
that receive interrupted rays of light emitted by the divergent
light source caused by the golf ball passing through the optical
sensor nets; detecting interruption times for the selected
detectors within the first and second arrays of light detectors
that detect interrupted rays of light; measuring dynamic spatial
information for the golf ball based on the detected interruption
times for the selected light detectors that receive interrupted
non-parallel rays of light; identifying second, third, and fourth
groups of selected light detectors for each of the first and second
arrays of light detectors that receive interrupted rays of light
emitted by the divergent light source caused by the golf ball
passing through the optical sensor net; detecting interruption
times for the second, third, and fourth groups of selected
detectors within the first and second arrays of light detectors
that detect interrupted rays of light; and computing dynamic
spatial information for the golf ball based on the measured
interruption times for the selected light detectors that receive
interrupted non-parallel rays of light.
26. The method for providing dynamic spatial information as recited
in claim 25, wherein the dynamic spatial information includes golf
ball speed and trajectory.
27. The method for providing dynamic spatial information as recited
in claim 25, wherein the dynamic spatial information includes club
speed information and swing path information.
Description
CROSS-REFERENCE TO OTHER APPLICATIONS
[0001] This application is related to the following U.S. Pat. No.
6,302,802 issued 16 Oct. 2001.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to golf analysis and analysis
devices. More specifically, the invention is directed to golf
analysis systems with optical sensor nets that capture and process
dynamic spatial information for a golf ball and/or a golf club.
[0003] There are a variety of apparatus and methods in the golf
industry that provide limited information relating to golf ball
trajectory and speed. Because a golf ball in flight generally
adheres to the same basic principles of physics as other projectile
objects, available systems today attempt to provide calculated
information such as estimated carry and flight path based on
numerous ball measurements obtained by a host of detectors and
other related equipment.
[0004] Many systems have been proposed in the past to measure
spatial positioning and information for a golf ball, a tennis ball
or any other spherical projectile. These systems generally include
numerous detectors and switches located along an expected flight
path for the object. The spherical object may thus impinge upon
particular detectors to thereby actuate corresponding electrical
switches. Many transmission type or reflection type photoelectric
switches may be also placed along an expected flight path, and may
be actuated when a ray input for particular switches are blocked
off by the object. Scanning laser beams have been also proposed
that are paralleled across an expected flight path of a spherical
object by using a concave mirror and lens system. The spherical
object may pass through a scanning plane to thereby measure beam
cut-off timing to determine launch positioning and angles for the
spherical object in flight. At the same time, visual systems have
also been provided that provide video camera images of the
projectiles to provide relevant spatial information.
[0005] There are many disadvantages to these present day analysis
and analysis systems which have been adapted for golf ball and club
swing analysis. For example, some systems affect the intended path
of the projectile or fail to obtain careful measurements which
provide inaccurate flight information. Most apparatus also require
a large number of switches, sensors or detectors to cover a
relatively wide flight path area for the spherical projectile. In
order to overcome some of the foregoing disadvantages or problems
of the conventional measuring methods, systems have been proposed
for determining the position of a flying spherical object with a
parallel light band generated and projected onto a screen to form a
linear image region. When a spherical object in flight crosses the
parallel light band, it creates a silhouette on the screen within
the image region. The position of this silhouette is detected by
using sensors to thereby determine an instantaneous spatial
position of the flying spherical object. The disadvantages for this
system have been further overcome with measuring apparatus that
purportedly determines instantaneous positioning of the object in
flight without coming into contact therewith. The flight
information may include speed, position and launch angle. Despite
the foregoing efforts, golf training systems today still require
excessive instrumentation and equipment.
[0006] The system disclosed in U.S. Pat. No. 6,302,802 addresses
many of the above-described issues. However, it requires a standout
post which can visually and physically hinder or interfere with the
player and also the ball flight. In addition, it does not have
left/right symmetry to allow both left and right handed players to
play under the same physical setting. Examples of the invention
described below will effectively answer such concerns and
limitations by requiring no standout post and allow both left and
right handed players to play under the same physical setting.
BRIEF SUMMARY OF THE INVENTION
[0007] Examples of methods and apparatus for golf analysis systems
with optical sensor nets are described. Dynamic spatial information
may be provided based upon either or both a golf ball and club
information. A compact, effectively single plane optical sensor net
is thus capable of capturing this information relating to a golf
ball and/or a golf swing. Plural optical sensor nets may also be
used with some examples. Relevant ball information may be measured
and derived with the systems described herein that includes ball
speed, ball take-off and azimuth angles, which may in turn provide
relevant calculated ball information such as ball spin, carry
distance, trajectory, flight time and height. Golf club information
may be also measured and derived to provide club swing path, head
speed (before and after impact) head twist and club face angle
throughout the swing.
[0008] Various examples of golf analysis systems provide ball
flight and club swing information with an optical sensor net formed
with intersecting rays of light. Ball speed and club speed
information maybe detected with either parallel or non-parallel
rays of light. Club path information may be provided based on
either parallel or non-parallel rays of light. It shall be
understood that particular features of the described embodiments
and examples in the following specification may be considered
individually or in combination with other variations and aspects of
the invention.
[0009] A first example of a golf analysis system includes a light
emitter assembly and a light detector assembly. The light emitter
assembly includes first and second light emitters spaced apart from
one another by first distance while the light detector assembly
includes first and second sets of light detectors arranged at a
first level along a surface of a practice area. The practice area
includes a tee region and an intended golf ball path extending from
a chosen tee location within the tee region. The first and second
sets of light detectors are positioned opposite one another and are
oriented transversely to the intended golf ball path. The first and
second light emitters are capable of emitting first and second
spreads of non-parallel light rays to be received by the first and
second sets of light detectors, respectively. The first and second
light emitters are located at a second level vertically above the
practice area by at least a second distance. The first and second
spreads of non-parallel light rays form an optical sensor net to
permit capturing relational kinetic information of at least one of
a golf ball and a golf club during a golf club swinging motion on
the practice area when at least one of the golf ball and golf club
passes through at least a portion of the optical sensor net. The
region above the first level and below the second level is
substantially free of mechanical structure to prevent inadvertent
contact between a golf ball or a golf club and such mechanical
structure during the golf club swinging motion.
[0010] In some examples of the golf analysis system, the first and
second light emitters emit laser light downwardly toward the first
and second sets of light detectors at angles of about 5.degree. to
15.degree. from vertical. In some examples, the second distance is
at least about 9 feet. In some examples, first and second light
emitter assemblies and first and second light detector assemblies
are used to define first and second optical sensor nets; the first
and second optical sensor nets can be oriented generally parallel
to one another. In some examples, the light emitters are capable of
providing information to a data processor.
[0011] An example of a method for enabling the determination of
dynamic spatial information for a golf practice swing using a golf
analysis system including an optical sensor net, is carried out as
follows. A golf practice swing is taken at the tee region of a
practice area of the golf analysis system with or without hitting a
golf ball along an intended golf ball path. At least one of a golf
club head and a golf ball hit by the golf club is passed along a
golf ball/club path through an optical sensor net. The optical
sensor net emits first and second spreads of non-parallel light
rays downwardly from first and second light emitters of a light
emitter assembly, the first and second light emitters spaced apart
from one another by a first distance and located vertically above
the practice area by at least a second distance. The optical sensor
net also receives the first and second spreads of non-parallel
light rays by first and second sets of light detectors of a light
detector assembly, respectively. The first and second sets of light
detectors are arranged along a surface of the practice area, with
each set of light detectors comprising a plurality of detector
elements. At least two of the non-parallel light rays are
interrupted by at least one of the golf club head and the golf
ball. Substantially all mechanical structures above and nearby the
practice area between the level of the practice area and the level
of the first and second light emitters are eliminated to prevent
inadvertent contact between the golf ball or the golf club and such
mechanical structures during the practice swing.
[0012] In some examples, the method also includes identifying light
detector elements that receive interrupted non-parallel light rays
as a result of the practice golf swing, measuring interruption
times for the identified detector elements that detect the
interrupted non-parallel light rays, and determining dynamic
spatial information for the golf club practice swing based on the
measured interruption times for the selected light detectors that
receive interrupted non-parallel rays of light; the identifying,
measuring and determining steps carried out using information
supplied by at least the light detector assembly providing data to
a data processor. In some examples, the method is carried out with
the tee location being undetermined.
[0013] Other features and advantages of the invention will become
apparent upon further consideration of the specification and
drawings. While the following description may contain many specific
details describing particular embodiments and examples of the
invention, this should not be construed as limitations to the scope
of the invention, but rather as an exemplification of preferable
embodiments. For each aspect of the invention, many variations are
possible as suggested herein that are known to those of ordinary
skill in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a somewhat simplified, overall view of a golf
analysis system using an optical sensor net.
[0015] FIG. 2 is a diagram illustrating the calculation of ball
speed based on the disruption of a sensor net with non-parallel
rays of light.
[0016] FIG. 3 is a simplified drawing demonstrating the calculation
of relative golf ball and club speed in accordance with another
aspect of the invention.
[0017] FIGS. 4 and B are diagrammatic explanations that describe
yet another aspect of the invention that provides directional
information for a golf ball path.
[0018] FIG. 5 is a diagrammatic explanation for determining the
path of a spherical projectile such as a golf ball based upon the
disruption of selected optical beams.
[0019] FIG. 6 is a simplified side view of another golf analysis
system that provides both golf club and ball dynamic spatial
information.
[0020] FIG. 7 is a simplified schematic diagram illustrating the
apparatus and steps involved with processing and receiving
information from the optical sensor nets described herein.
[0021] FIG. 8 is an example of visual output that may be provided
by the apparatus described herein that includes relative golf club
and ball information.
[0022] FIGS. 9A-B are simplified illustrations describing the
off-centered contact and effect on a golf ball in relation to the
club head.
[0023] FIGS. 10A-B are enlarged visual output illustrations that
provide captured golf club information after contact with a golf
ball.
[0024] FIG. 11 illustrates an example of a golf analysis system
similar to that of FIG. 1 but in which the light emitter assembly
is positioned above the light detector assembly.
[0025] FIG. 12 is a front view of the golf analysis system of FIG.
11.
[0026] FIG. 13 is a simplified side view of the golf analysis
system of FIG. 11.
[0027] FIG. 14 is an exaggerated view similar to FIG. 13 showing
how the first and second sets of light detectors of the light
detector assembly are spaced apart from one another so that the
light rays from the first and second light emitters of a light
emitter assembly are at slightly different angles to the
vertical.
[0028] FIG. 15 is a view similar to that of FIG. 13 of another
example of a golf analysis system using two light emitter
assemblies and two light detector assemblies to create two optical
sensor nets spaced apart from and generally parallel to one
another.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The following description will typically be with reference
to specific structural embodiments and methods. It is to be
understood that there is no intention to limit the invention to the
specifically disclosed embodiments and methods but that the
invention may be practiced using other features, elements, methods
and embodiments. Preferred embodiments are described to illustrate
the present invention, not to limit its scope, which is defined by
the claims. Those of ordinary skill in the art will recognize a
variety of equivalent variations on the description that follows.
Like elements in various embodiments and examples are commonly
referred to with like reference numerals.
[0030] This invention is based on the method and apparatus
disclosed in U.S. Pat. No. 6,302,802. FIGS. 1-10B and the
associated description of those figures are taken from that
patent.
[0031] FIG. 1 illustrates a golf analysis and training system 10
with an optical sensor net 20 provided in accordance with the
invention. An important advantage provided by the example of FIG.
1, as well as with the example of FIG. 11, is that the ball may be
placed at various locations with respect to optical sensor nets
within the analysis systems described herein. The ball is not
necessarily positioned at a fixed spot as with most earlier
apparatus. An individual may thus strike golf balls freely without
multiple sensors and fixed tee positions which may be selected
nonetheless in order to provide even more ball and club
information.
[0032] As shown in FIG. 1, the analysis system 10 may include a
substantially L-shaped frame having a first leg 12 and a second leg
14 or extension. The first leg 12 may be positioned in a relatively
horizontal position, and the second leg 14 may be placed in a
substantially vertical tilted position. Either or both legs may be
formed with a bent configuration to form a curved shape. The system
may further include a light emitter assembly with a first light
emitter 16 connected to the first leg 12 of the frame, and a second
light emitter 18 connected to the second leg 14 of the frame. Each
light emitter 16 and 18 may emit a spread or fan of non-parallel
light rays in a substantially single plane. The first and second
light emitters 16 and 18 may also emit pulsed laser beams, and may
be filtered to differentiate the rays of light produced by ambient
illumination from those produced by the golf ball crossing the
optical sensor net 20.
[0033] In other examples, the light emitter assembly may include at
least one optical beam splitter to split a single beam of light
from the light emitter equally to its respective light detectors.
The light emitter assembly may thus provide a focused laser beam
and a beam splitter that generates diverging rays of light that are
received by light detectors within the system. A variety of
anti-reflective coatings may be selected as is known in the art to
promote permeation of light rays through the beam splitter and
other components of the light emitter assembly.
[0034] The optical sensor nets provided herein are capable of
measuring and processing relational dynamic information for both a
golf ball and a golf club. An array of light detectors with a first
set of spaced apart light detectors may be positioned along the
first leg of the frame to receive the non-parallel light rays
emitted from the second light emitter. A second set of spaced apart
light detectors may be positioned along the second leg of the frame
that receive the non-parallel light rays emitted from the first
light emitter. The array of light detectors on the first leg and
the second leg of the frame may be spatially aligned and arranged
at a predetermined space interval that is less than the radius of
the golf ball. As a result, the non-parallel rays from both the
first and the second light emitter provide an asymmetrical optical
sensor net that captures relational kinetic information for a
spheroidal object such as a golf ball and a golf club during a
swinging motion when passed through at least a portion of the
sensor net. Moreover, the asymmetrical optical sensor net may
provide a two-dimensional and single planar optical net having
relatively uniform density. The size of the sensor net may be
varied according to desired operating parameters, and may
preferably have dimensions ranging from 2 to 4 feet. Various
combinations of additional light emitters and detectors may be
selected.
[0035] A data processor 22 may be also provided with the optical
sensor net that is in communication with the light emitter
assembly, the array of detectors or any combination of selected
components within the golf analysis system. The data processor or
computer 22 may be connected to timers and related instrumentation
to measure periods of disruption for selected light detectors by
the golf ball and by the golf club. Moreover, the data processor
may process relational kinetic information for the golf ball and
the golf club based on the disruption of selected light detectors
and their respective time periods of disruption. A visual display
24 may be further provided to display data generated from the
movement of the golf ball and/or golf club.
[0036] As shown in FIG. 1, the golf analysis device may include an
optical grid or net 20 positioned at an angle. A generally L-shaped
frame for the system may be positioned with respect to the ground
at a preselected or variable angle (.theta.). A relatively
horizontal leg portion 12 of the frame may rest on the ground in
proximity to the ball hitting area, and a relatively vertical leg
portion 14 of the frame angle may extend upwardly in a general
direction towards the player. The frame angle .theta. may range
from about 10 degrees to 90 degrees, and preferably between about
30 to 60 degrees. The vertical leg portion 14 may also include a
stand or support to assist in maintaining the frame in a relatively
fixed position. The open-construction of an L-shaped frame
described herein enables a player to swing through the optical
sensor net with minimal risk of striking portions of the analysis
system. Other frame configurations may be selected having
additional leg sections that permit free passage of a golf ball
and/or club through the optical sensor nets 20 described herein.
The angled configuration of the system 10 also captures relatively
more golf club information during the swing, particularly when
positioned relatively close to the individual player thus providing
a compact golf analysis system. The tilted frame positioned at
preferable angles tends to capture higher angles of changing golf
shots with different trajectories. Moreover, the angled positioning
of the frame and sensor net may provide improved resolution of golf
club swing information. Dynamic spatial information for a golf ball
may be similarly captured and processed simultaneously. After the
golf ball passes through the optical sensor net 20, it may be
retrieved or caught in a ball net, not shown, positioned along the
flight path of the ball to allow an individual to hit multiple
balls in order to gather more golf ball and club information.
[0037] Another variation provides an optical sensor system for
measuring dynamic spatial information of a substantially spheroidal
projectile. The sensor system may include a support frame having at
least two extensions with at least one light source or laser that
emits non-parallel rays of light. Each light source may be
positioned at a location along the frame in a predetermined plane
or pattern. A plurality of light detectors may be aligned and
arranged at predetermined spatial intervals along the support
frame. The light detectors may be also positioned and spaced apart
for detecting the non-parallel rays of light emitted from a light
source. A first light source may emit a first set of non-parallel
rays of light to a first set of light detectors, and a second light
emitter may emit a second set of non-parallel rays of light to a
second set of light detectors. The light source may be a
semiconductor diode laser with a cylindrical lens positioned along
an optical axis that provides divergent rays of light to form a
substantially fan-shaped pattern or configuration. For example, the
light source may be arranged to emit a laser beam of 3-20 mW in
consumptive power and 630-790 nm in wave length. A variety of other
light sources with different power and frequency output may be
selected to form an array of non-parallel rays of light. Selected
lenses, filters and beam splitters may be also selected to provide
dispersion of the light rays from a single light source.
Additionally, a variety of light detectors or photosensors may be
selected in accordance with the invention including PIN, MSN and
diodes which are available from vendors like Hewlett-Packard,
Temic, Siemens and Hamamatsu.
[0038] The first and the second set of light detectors within the
analysis system may detect intersecting non-parallel rays of light
to provide an asymmetrical two-dimensional or single planar optical
sensor net. The sensor net may be formed at a variety of angles
with respect to the ground, preferably angled more towards an
individual player to capture more swing information and to provide
a compact system. The various interruptions of the rays of light
within the sensor net may be thus detected and measured when the
spheroidal projectile, club shaft, and club head pass through the
rays of light. A data processor and instrumentation may be also
selected for communication with the plurality of light detectors to
measure a plurality of interruption times in which the rays of
light to selected light detectors are interrupted or blocked off by
the spheroidal projectile. Moreover, the data processor or
microprocessor may process and provide dynamic spatial information
for the spheroidal projectile based on the location and the
interruption time for each selected light detector. Given the
diameter length of the spheroidal object, each light detector may
be spaced apart a defined distance that is less than the radial
length of the spheroidal object so that at least two rays of light
are interrupted. A variety of predetermined information for the
projectile or golf ball may be further stored in a memory coupled
to the microprocessor. The combination of stored information and
measured readings from the optical sensor net within the analysis
system provide dynamic spatial information for the spheroidal
projectile such as its speed and direction. This information may be
in fact derived without a predetermined initial position or
velocity for the projectile. A distinct advantage provided in
accordance with the invention is the calculation of dynamic ball
information without necessarily fixing the distance between a golf
ball and the sensor net. Additional sensors and switches may be
included in the analysis system nonetheless to determine an initial
launch event or location, but is not required. Moreover, the
dynamic spatial information may include certain correction factors
that account for variable playing conditions such as wind speed and
direction, humidity, temperature, pressure. These environmental
conditions may reflect existing hitting conditions or various
simulations that may be stored in the system memory, and executed
upon command as desired by the individual.
[0039] As shown in FIG. 2, the calculation of ball speed and
direction may be based on the measured disruption of light rays
within an optical sensor net formed with non-parallel rays of
light. Three or more rays of light may be disrupted within the
sensor net. A plurality of individual detectors (n, n+1, n+2 . . .
) may detect their respective rays of light which may be spaced
apart a predefined distance. For example, when multiple laser beams
are cross-sectionally sectionally blocked off by a flying golf ball
30, the measured blocking time (t.sub.n, t.sub.n+1, t.sub.n+2 . . .
t.sub.n+i) may correspond or translate into the physical length of
cross-sectional portions of the ball (d.sub.n, d.sub.n+1, d.sub.n+2
. . . d.sub.n+i). t.sub.n may be defined as the time interval that
blocks off a ray of light for the n.sup.th detector, and the time
base may be measured and provided by the instrumentation within the
analysis system. d.sub.n may be defined as the length of the
distance for the ball that blocks off light being directed to the
n.sup.th detector. Because the golf ball diameter and curvature may
be predetermined as a known variable, and the beam interruption
times may be measured, the entire image of the ball may
reconstructed along with its discrete cross-sectional paths. Once
the image of the golf ball is fitted or matched against the
cross-sectional paths, the location of the center of mass may be
obtained. Accordingly, the ball speed, direction and trajectory may
be based upon measurable ball path information that is derived from
the laser beam blocking paths.
[0040] In accordance with this aspect of the invention, an optical
sensor system may thus provide instantaneous dynamic information
for a spherical projectile such as a golf ball. The sensor system
may include a structural support frame with at least one light
emitter assembly that emits non-parallel rays of light to form an
optical sensor net. The support frame can be formed with two
extensions that generally provide an L-shaped design. A first light
emitter assembly may be positioned on the first extension, and a
second light emitter assembly may be positioned on the second
extension. The light emitter assemblies may each include a light
source and an optical element or lens that provides non-parallel
rays of light. The light emitter may be a focused laser light
source, or non-coherent LED or white light, and the optical element
may be a beam splitter or cylindrical lens. Each laser light source
may provide a focused laser beam through an optical beam splitter
to split rays of light equally to a plurality of selected light
detectors. The light detectors may be spatially arranged to form an
asymmetrical optical sensor net for detecting the multiple rays of
light emitted from the light emitter. Furthermore, the light
detectors may be positioned along the support frame and spaced
apart at selected or predetermined spatial intervals for detecting
the non-parallel rays of light emitted from the first and the
second light emitter assemblies. These spatial intervals may be
varied, and may be equal to or less than a predetermined radius for
a golf ball. As a result, the flying spherical object blocks off at
least three rays of light to provide dynamic spatial information in
accordance with the invention. The light detectors may be further
arranged relatively vertically or horizontally in-line with the
light emitter assembly to detect emitted light and the interruption
times for respective rays of light when the spherical projectile
passes through the optical sensor net. In addition, the sensor
system may include instrumentation and a data processor in
communication with the light detectors for measuring and processing
a plurality of interruption times in which the rays of light to
selected light detectors are interrupted or blocked off by the
spherical object. The blockage time of the rays of light may be
measured and inputted into a computer with arithmetic operators
that detect a single or a plurality of photodiodes for which the
rays of light are blocked off. A system microprocessor may be also
selected for processing and calculating substantially instantaneous
dynamic information for the spherical projectile based on available
information including the location and the interruption time for
each selected light detector. Additionally, a visual display may be
selected to display data generated from the movement of the golf
ball.
[0041] Another aspect of the invention provides dynamic spatial
information for both a golf ball and a club. As shown in FIG. 3,
the variation of the invention may include optical sensor nets
similarly described herein with either non-parallel or parallel
rays of light. As with other embodiments of the invention described
herein, ball and club speed may be calculated without tee sensors
or hitting the ball from a fixed location. An optical sensor net 32
may be positioned in the line of the intended ball path 34 to
capture information relating to the ball 30 and the golf club 40
based upon the disruption times for selected rays of light. An
L-shaped frame may be selected for these analysis systems to allow
an individual to hit the ball 30 and swing through the sensor net
32. When the golf ball 30 passes through the optical net 32, the
initial time may be established t=0. The time for detecting the
ensuing golf club by the optical net 32 following the golf ball 30
may be defined as t=t.sub.c. At this time, it may be assumed the
ball 30 was hit at t=x which is unknown at this point. The club
speed after impact may be expressed as:
V ca = d c t c - X ##EQU00001##
[0042] Ball speed may be defined as:
V b = d b - X ##EQU00002##
[0043] g may be also determined by experimental data, and may
represent the potential energy of the shaft during impact of the
club to the ball. Accordingly, when the principle of the
conservation of energy is applied then:
1 2 M c V cb 2 = 1 2 M b V b 2 + 1 2 M c V ca 2 + g ( 1 2 M c V ca
2 ) ##EQU00003##
[0044] wherein M.sub.c is the mass of the club, V.sub.cb is the
velocity of the club before impact, M.sub.b is the mass of the
ball, V.sub.b is the velocity of the ball after impact, and
V.sub.ca is the velocity of the club after impact. f may represent
the speed ratio which is related to the club and ball momentum
transfer due to impact, and may be a function of the ball speed
that is determined by experimental data.
V cb = V ca 2 + a V cb 2 f 2 + g V ca 2 ##EQU00004##
[0045] wherein a is the mass ratio between the club and the ball, a
equals approximately M.sub.b/M.sub.c
V cb 2 = V ca 2 ( 1 + g ) + a f 2 V cb 2 ##EQU00005## V cb = 1 + g
1 - a f 2 V ca ##EQU00005.2## A = 1 + g 1 - a f 2 V ca
##EQU00005.3## X ( t c ) = f d b t c f d b - d c ##EQU00005.4##
wherein t.sub.c is the measured time data between the ball and the
club passing through the optical sensor net, d.sub.c=d/cos
.theta.c, and d.sub.b=d/cos .theta.b. As a result, the following
may be obtained:
V b ( t c ) = d b - X ( t c ) ##EQU00006## V cb ( t c ) = V b ( t c
) f ##EQU00006.2## V ca ( t c ) = V cb ( t c ) A ##EQU00006.3##
[0046] Based upon experimentation and field analysis, f has been
determined by the following expression:
f(V.sub.b)=(0.07+0.04 V.sub.b)
[0047] wherein V.sub.b may be measured in mph or miles per hour,
and g has been determined to be between 0.01 and 0.1 depending upon
the shaft selected. Accordingly, with the above calculations, the
ball speed (V.sub.b) and the club speed (V.sub.ca) may be
calculated without having a sensor positioned at a tee position. It
has been observed that the accuracy in determining speed is better
than 0.1% if a spacing of about 10 inches is used between the net
and the tee positions. In the tilted frame configuration, this
calculation may be readily determined since d.sub.b and d.sub.c may
be readily determined from the frame position regardless if it is
relatively perpendicular to the ground at 90 degrees or tilted.
[0048] A method can provide dynamic spatial information based upon
the relations described above for moving objects with an optical
sensor net. The method may include the initial selection of a
sensor system with a divergent light source for emitting at least
two non-parallel rays of light towards an array of light detectors
to form an optical sensor net. At least one moving object such as
ball and/or golf club may pass through the non-parallel rays of
light within the optical sensor net to interrupt emission of the
rays of light to the array of light detectors. Selected light
detectors may be identified that receive interrupted rays of light
emitted by the divergent light source caused by the moving object
passing through the optical sensor net. The interruption times for
the selected detectors within the array of light detectors may be
measured, and the dynamic spatial information may be thus provided
for the moving object based on the measured interruption time for
the selected light detectors that receive interrupted non-parallel
rays of light. The moving object may be a golf ball with a
preselected diameter, a golf club or both.
[0049] Another variation for this aspect of the invention may
include parallel or non-parallel laser beams to improve the
accuracy of determining the ball and club positions by applying the
concept of a weighting correction. When the frame is titled, at
different ball takeoff and azimuth angles, the number of beams that
will be blocked off by the ball and the club will be different. It
is thus possible to use the total number of beams blocked off by
the ball at different angles to improve the accuracy of determining
the ball and club positions as shown in FIGS. 4A-B. Depending on
the relative angle of the optical sensor net, and flight path of
the ball and the swing path of the golf club, the number of optical
beams that are blocked will be different. In one instance, as shown
in FIG. 4A, only beams #2, 3 and 4 are blocked by a passing ball.
Meanwhile, in FIG. 4B, beams #2, 3, 4 and 5 are blocked when the
ball and/or optical net are positioned at relatively different
angles. The number of beams blocked, for how long, and in which
sequence, all provide information in accordance with this aspect of
the invention to provide ball information such as speed and
direction.
[0050] With respect to yet another aspect of the invention, as
shown in FIG. 5, the ball speed and its relative direction may be
detected with parallel or non-parallel beam of light without
knowing the initial starting or tee position of the ball. An outer
frontal surface of the golf ball intercepts an optical beam plane
upon contact. The golf ball intercepts optical beam #1, 2, 3, 4 and
5 at t=t.sub.1, t.sub.2, t.sub.3, t.sub.4, and t.sub.5,
respectively. By examining the time ratio of t.sub.1, t.sub.2,
t.sub.3, t.sub.4 and t.sub.5 (since the curvature of the golf ball
may be considered a given parameter), the ball speed and direction
may be determined without knowing its original position by:
[0051] Step 1: determining how many beams are blocked
[0052] Step 2: determining which beam is blocked first
[0053] Step 3: determining the time ratio between each beam in
reference to the first beam
[0054] Step 4: since there is only one direction of the traveling
ball that will match the time ratio given by the data, the
direction of the ball may be determined with appropriate time
resolution between the blocking times for each beam t.sub.1 . . .
t.sub.5
[0055] Step 5: once the direction or the relative angle with
reference to the optical beam plane is known, the ball speed may be
also determined based on the interruption time by the ball with a
known curvature.
[0056] This first example thus provides methods and apparatus for
calculating ball traveling information without fixing the ball
starting position or the time of impact when the club hits the
ball. The time ratios between different blocked beams are measured
to provide ball flight information. By applying the curvature of
the ball, and by knowing the time when each beam is blocked, the
ball location may be better estimated by using a simple averaging
method.
Ball Center Position = i = 1 N ( i th beam position ) .times. (
.DELTA. t i ) i = 1 .DELTA. t i ##EQU00007##
[0057] N may be defined as the number of beams blocked by the
ball.
[0058] Another aspect of the invention provides dynamic spatial
information for a golf club as it passes through optical sensor
nets described herein. With respect to this variation of the
analysis systems described herein, as illustrated in FIG. 6,
portions of the club shaft 46 and the club head 48 are detected and
monitored by the sensor net 42 as the club passes through. In
addition to detecting ball flight path 44 and information as
described herein, the analysis system may determine both the club
swing path 52 and any twisting of the club head due to torque
applied by hitting the golf ball off-center with respect to the
center of gravity for the club head. Although a tilted L-shaped
frame is shown in FIG. 6, it shall be understood that frames with
other configurations may be selected that are not tilted.
Similarly, the optical sensor net 42 may include both parallel and
non-parallel rays of light with respect to this aspect of the
invention. The swing path 52 and club head movement may be detected
and tracked with the optical sensor net 42, and relevant time data
may be collected or measured so that important golf swinging
information may be observed and communicated to a player. When a
player is preferably positioned relatively close to the net 42 so
that club information may be determined, both ball and golf club
information may be derived by identifying which light detectors are
disrupted, and for how long. The initial disruption of the net 42
is typically caused by the golf ball 50 passing through, which may
be followed by the club head 48. A method may be thus provided in
accordance with the invention for obtaining dynamic spatial
information which includes the step of passing a golf club through
either parallel or non-parallel rays of light within the optical
sensor net to interrupt emission of the rays of light to the array
of light detectors. A group of selected light detectors may be
identified that receive interrupted rays of light emitted by the
divergent light source caused by the golf club passing through the
optical sensor net. The interruption times for the rays of light to
this group of selected detectors may be detected and measured
within the system. As a result, dynamic spatial information may be
computed for the golf club based on the measured interruption time
for the selected light detectors that receive interrupted
non-parallel rays of light. This includes club speed and swing path
information. Similarly, another group of selected light detectors
may detect and measure interruption times for a golf ball to
provide relevant ball information such as speed and trajectory as
it also passes through the net when the swing analysis system is
configured to not only detect the golf club swing.
[0059] FIG. 7 is a simplified schematic diagram illustrating the
apparatus and steps involved with processing and receiving
information from the optical sensor nets described herein. A
microprocessor control system may be provided that comprises a set
of detectors and lasers mounted on a mechanical frame to form an
optical detection net. The system may further include an analog to
digital (A/D) converters or conditioning circuitry, a computer or
central processing unit (CPU) that receives or takes the detector
input to perform selected or necessary logic determination, a
read-only memory (ROM) bank that may contain the algorithms for
performing CPU computations, a random access memory (RAM) bank that
stores computational data, a logic decoder, and sets of output
ports such as serial bus or universal serial bus (USB) that
communicates with displays and/or other personal computers.
[0060] When a golf player swings a club to make impact to a golf
ball, the ball passes through the optical net first to trigger the
electronic circuitry within the computerized analysis system to
commence the collection of data relating to both the golf ball and
the club. After the circuitry is initially triggered by the
relatively fast moving golf ball, the microprocessor and RAM may
begin to collect the data over a predetermined period of time until
the following club passes through the optical net to acquire all
needed data for computation. The ball and club swing path signals
received from the laser light detectors may be first sorted by the
analog to digital (A/D) circuitry for proper coordinate and
time-duration information. The collected information may be
subsequently analyzed by the microprocessor or CPU using the
predetermined algorithm that may be stored in memory or the ROM
bank. After microprocessor computation is performed, the computed
data may be temporarily kept in the RAM for additional computation
if needed or desired. The determined ball speed, ball take-off
directions, ball traveling trajectory, club swing path, club face
angle, and club head twisting information may be then directed
through the decoder to communicate with different peripherals
including displays and other computer systems for additional
processing such as other golf analysis, training and gaming
applications including home entertainment systems and video games.
After the ball and club swing information is passed to the display
or additional PCs, the electronic system may be reset to receive
new data. An LED indicator on the optical frame may be lighted to
indicate the readiness (READY) of the unit for next play or golf
shot.
[0061] With the electronic detection circuitry and apparatus
described herein, a printed visual output may be provided as shown
in FIG. 8 that includes relative golf club and ball information.
The output may include an image representing the path of the ball
and a separate image representing the golf club. A horizontal axis
of the output may be divided to illustrate images of the ball and
club along both the X-axis and the Y-axis. The output may be
derived from the disruption of rays of light within the net, and
may be translated into images corresponding to selected detectors
that are disrupted. At the same time, a vertical axis of the output
may be a time scale starting from time=0 when a first group of
disruption times for selected detectors in the net is observed
which is typically caused by the ball, and a second group of
disruption times for selected detectors in the net caused by the
club. A variety of time scales may be also selected for these
systems including a 10.sup.-6 second scale as shown to capture data
from the optical sensor net. The general path of the ball may be
tracked with the image provided in relation to a complementary
image of the club shaft. The flex of the club shaft may be even
observed with the displayed output. As with other embodiments of
the invention described herein, a compact sensor net with a tilted
design may provide more relevant golf club information since a
relatively larger portion of the club shaft and head information
may be captured by the closely positioned sensor net. The combined
information and output may be thus used to calculate the ball
flight and club swing to provide realistic or near realistic ball
trajectory predictions.
[0062] A variety of algorithms may be developed for the golf
analysis systems described herein to provide pattern recognition of
club swing information that indicate club head twist direction
after impact with a golf ball. For example, as shown in FIGS. 9A-B,
an off-centered contact with the ball as with toe shots cause the
club head to generally rotate in a clockwise rotation as
illustrated. A toe shot generally occurs when contact with the ball
is not made with its center of mass (CM), and away from the player.
The club head and shaft image is captured by the optical sensor
nets provided herein as a function of time as illustrated in FIGS.
10A-B. The club image for a toe shot may be captured along an
X-axis and plotted against time as shown in FIG. 10A. Similarly,
when a head shot occurs wherein the contact with the ball is not
made with the center of mass for the club and is towards the
player, the club head may generally rotate in a relatively
counter-clockwise rotation. As illustrated in FIG. 10B, the club
image for a head shot may be captured to reflect this type of
contact with the golf ball. Based upon the club swing information
provided with the optical sensor nets systems herein, corrective
steps may be prescribed during training so desirable square contact
between the golf ball and golf club can be achieved.
Examples of Frameless Golf Analysis Systems and Methods
[0063] The following will describe examples of golf analysis
systems 10 in which the light emitter assembly 11 is positioned
above the light detector assembly 13, sometimes referred to as
frameless golf analysis systems 10. A first example of frameless
golf analysis system 10 is shown in FIGS. 11-13. First and second
light emitters 16, 18 are mounted to the ceiling 56 or other
frameless structure spaced apart from one another by a first
distance 58. First distance 58 is typically about 2-4 feet. The
vertical distance 59 between ceiling 56 and a support surface 60 is
typically about 9-12 feet. A practice area 62, typically in the
form of a practice area mat 62, is positioned beneath light emitter
assembly 11 and is used to support a tee 64 at a chosen tee
location 66 within a tee region 68. In some examples, chosen tee
location 66 is fixed while in other examples, it may be changed.
Practice area mat 62 can be made of, for example, a firm
elastomeric material having a thickness of about 1-3 inches
[0064] Light detector assembly 13 includes first and second sets
70, 72 of light detectors 74. Although first and second sets 70, 72
of light detectors 74 can be mounted on top of practice area mat
62, they are preferably embedded within practice area mat 62. The
distance 75 between the ends of light detector assembly 13 is
typically corresponds to first distance 58, typically in a range of
2-4 feet. However, in some cases it may be desired to make the
distances 58, 74 substantially different from one another, such as
if the shape or size of optical sensor net 20 is to be changed.
Light detectors 74 in each set 70, 72 are preferably spaced apart
from one another by a distance no greater than about the minimum
radius of a typical golf ball, typically about 0.8 inch. First
light emitter 16 directs a first spread of first light rays 26 at
the light detectors 74 of first set 70 of light detectors. Second
light emitters 18 direct a second spread of second light rays 28 at
the light detectors 74 of second set 72 of light detectors. The
region where first and second light rays 26, 28 overlap one another
is referred to as the optical sensor net 20.
[0065] With golf analysis system 10 shown in FIG. 1, all of the
light detectors are arranged in a common plane. The calculations
for this configuration of FIG. 1 are discussed above with regard to
FIGS. 1-10B. However, with the frameless golf analysis system 10 of
FIGS. 11-13, if detectors 74 for both of the first and second sets
70, 72 of light detectors were aligned, then detectors 74 would not
be able to differentiate between first light rays 26 from first
light emitter 16 and second light rays 28 from second light
emitters 18 without making the system more complicated by, for
example, having first and second light rays 26, 28 at different
frequencies coupled with the ability to distinguish between the
different frequencies of light received by detectors 74. Therefore,
it is presently preferred that the first and second sets 70, 72 of
light detectors be separated a short distance from one another
while being oriented parallel to one another. The separation is
shown in an exaggerated manner in FIG. 14.
[0066] To put X.sub.1 and X.sub.2 (two interrupted spatial
coordinates by a flying golf ball 30 or a swinging club shaft 40 or
a swinging club head 48) onto the same space plane, a special
coordinate algorithm that matches the shape of the optical sensor
net geometry is used to find the distance d between X.sub.1 and
X.sub.2. Because the space coordinates of the frameless golf
analysis system 10 of FIGS. 11-14 has 2-fold symmetry along the
target line, meaning the coordinates space out in actual space are
left-right mirror imaged in reference to the target line, the space
coordinates can be uniformly distributed within the detection area.
This is in contrast to the situation where the space coordinates
are asymmetrical and not uniformly distributed. Thus it is possible
to use the frameless golf analysis system 10 of FIGS. 11-14 to
calculate the ball take-off and azimuth angles by determining the
actual and predicted intercept time differences between adjacent
intercepted beam. This algorithm may be explained as follow.
[0067] As described earlier, the ball center position can be
generally determined by
Ball Center Position = i = 1 N ( i th beam position ) .times. (
.DELTA. t i ) i = 1 .DELTA. t i ##EQU00008##
[0068] N may be defined as the number of beams blocked by the ball.
The ball speed can be determined by measuring the longest intercept
time for the golf ball to travel through laser beams.
Ball speed (Vb)=[(golf ball radius)*(ball curvature and center
position adjusted distance factor)/(longest laser beam intercept
time)]
[0069] Once the ball center location is known and ball speed
determined, based on the curvature of the ball the starting point
of each intercepted coordinate (i.e., beams blocked) can then be
predicted if the ball is traveling along the perpendicular
direction toward the laser beams. If in reality the ball is now
traveling in directions other than the perpendicular one then the
actual measured intercept time, relative to each adjacent laser
beam, will be different from the predicted time. Thus if one can
determine the initial block-the-beam time and its difference to the
predicted time in Y direction (left-right), then it represents the
effect due to azimuth angle, and in Z direction (up-down) then it
represents the effect due to take-off angle. Thus after the first
beam is blocked, the time of the adjacent beam to be blocked can be
predicted if the ball is traveling in the perpendicular direction
to the beam and measured based on the actual travel direction, then
the angles may be calculated based on the following equation:
Delta angle=arctan {[(predicted time)-(actual time)-(ball curvature
correction factor)]/predicted time}
[0070] The actual azimuth and take-off angles will be further
corrected by the tilting angle .theta. of the laser beams which is
defined in FIG. 11. This is new features based on the frameless
golf analysis system 10 of FIGS. 11-14 where the laser beams are
2-fold symmetry and uniformly distributed within the detection
area, comparing to the prior art arrangement where the laser beams
are asymmetry and non-uniformly distributed.
[0071] This special coordinate algorithm will then assign
X.sub.1'=X.sub.1+d/2 and X.sub.2'=X.sub.2-d/2, which will shift
X.sub.1'+X.sub.2' onto the same space plane for ball-information
calculations. In the example of FIGS. 11-13, first and second sets
70, 72 of light detectors are very close to one another so that the
tilt angle .theta. is slightly different for each. Tilt angle
.theta. is preferably about 5 degrees to 15 degrees. In the example
of FIGS. 11-13, .theta..sub.11 is equal to about 9.46 degrees and
.theta..sub.12 is equal to about 9.59 degrees. The rest of the
calculations remain identical to those discussed above with regard
to FIGS. 1-10B.
[0072] FIG. 15 is a view similar to that of FIG. 13 of another
example of a golf analysis system 10 using two light emitter
assemblies 11A and 11B along with two light detector assemblies 13A
and 13B. Doing so creates two optical sensor nets 20A and 20B
spaced apart from and generally parallel to one another. First
optical sensor net 20A is oriented as a first tilt angle
.theta..sub.1 while second optical sensor net 20B is oriented at a
second tilt angle .theta..sub.2. The first and second tilt angles
may be the same or different. The distance 76 between first and
second light detector assemblies 13A and 13B is typically equal to
about 25% to 100% of distance 75 between the ends of light detector
assembly 13. One advantage of system 10 of FIG. 14 is that chosen
tee location 66 can be changed by the user without requiring any
input into the system. This is because the two separate sensor nets
can provide the needed spatial information (since two points can
define a straight line of objective motion in space) required to
calculate both ball and clubhead motions in space without the
prerequisite of defining the tee location with good accuracy.
Two-sensor nets can also provide a parallel check on each other
(when used as an individual sensor net) to ensure there will be no
miscalculation occur during the ball and clubhead motion detection
and calculation. A disadvantage associated with the use of
two-sensor net is the extra cost involved.
[0073] A primary advantage of using frameless golf analysis systems
10 as shown in FIGS. 11-15 is the elimination of the presence of
the legs 12, 14 of the frame in the example of FIG. 1. Even if legs
12, 14 do not interfere with a user's golf swing, the presence of
the frame legs can sometimes be viewed negatively by the user.
Another advantage over the example of FIG. 1 results from frameless
system 10 having left-right symmetry so it will allow both left
handed as well as right-handed players to play on the same system
setup without any changes or modifications.
[0074] The above descriptions may have used terms such as above,
below, top, bottom, over, under, et cetera. These terms may be used
in the description and claims to aid understanding of the invention
and not used in a limiting sense.
[0075] While the present invention is disclosed by reference to the
preferred embodiments and examples detailed above, it is to be
understood that these examples are intended in an illustrative
rather than in a limiting sense. It is contemplated that
modifications and combinations will occur to those skilled in the
art, which modifications and combinations will be within the spirit
of the invention and the scope of the following claims. For
example, although each set 70, 72 of light detectors 74 arrange the
light detectors in straight lines, in some situations it may be
desired to have light detectors 74 are arranged in other than
straight lines. Although it is presently preferred to use a single
light emitter 16, 18 for each set 70, 72 of light detectors, if
desired more than one light emitter may be used for each set of
light detectors, even to the point of using a separate light
emitter for each light detector 74 (too extreme to be implemented).
In each of the examples, light emitter assembly 11 is located
vertically above a position between tee 64 and light detector
assembly 13; in some examples, light emitter assembly 11 may be
positioned directly vertically above light detector assembly 13 or
in front of the light detector assembly; however having optical
sensor net 20 tilt forwardly to a more vertical position would
reduce the amount of swing information and increase the size of the
overall system structure in order to capture the same amount of the
information.
[0076] Any and all patents, patent applications and printed
publications referred to above are incorporated by reference.
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