U.S. patent application number 11/594124 was filed with the patent office on 2007-05-10 for golf ball performance evaluation system.
This patent application is currently assigned to BRIDGESTONE SPORTS CO., LTD.. Invention is credited to Takuichi Shimizu.
Application Number | 20070105637 11/594124 |
Document ID | / |
Family ID | 38004478 |
Filed Date | 2007-05-10 |
United States Patent
Application |
20070105637 |
Kind Code |
A1 |
Shimizu; Takuichi |
May 10, 2007 |
Golf ball performance evaluation system
Abstract
A golf ball performance evaluation system includes an initial
properties analyzing unit for measuring and analyzing kinetic
properties of a golf ball immediately after the golf ball is hit by
a golf club, and an in-flight properties analyzing unit for
measuring and analyzing kinetic properties of the golf ball hit by
the golf club during a flight on its trajectory.
Inventors: |
Shimizu; Takuichi; (Saitama,
JP) |
Correspondence
Address: |
SUGHRUE-265550
2100 PENNSYLVANIA AVE. NW
WASHINGTON
DC
20037-3213
US
|
Assignee: |
BRIDGESTONE SPORTS CO.,
LTD.
|
Family ID: |
38004478 |
Appl. No.: |
11/594124 |
Filed: |
November 8, 2006 |
Current U.S.
Class: |
473/151 |
Current CPC
Class: |
A63B 2225/74 20200801;
A63B 43/008 20130101; A63B 2220/05 20130101; A63B 2024/0031
20130101; G01S 13/58 20130101; A63B 2220/16 20130101; A63B 2220/35
20130101; A63B 2220/807 20130101; A63B 2024/0034 20130101; A63B
69/3658 20130101; A63B 24/0021 20130101; A63B 2220/805 20130101;
A63B 2220/30 20130101; G01S 13/88 20130101; A63B 2220/89 20130101;
A63B 69/3614 20130101; A63B 24/0003 20130101; A63B 71/06
20130101 |
Class at
Publication: |
473/151 |
International
Class: |
A63B 69/36 20060101
A63B069/36 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 8, 2005 |
JP |
P2005-323712 |
Claims
1. A golf ball performance evaluation system comprising: an initial
properties analyzing unit for measuring and analyzing kinetic
properties of a golf ball immediately after the golf ball is hit by
a golf club; and an in-flight properties analyzing unit for
measuring and analyzing kinetic properties of the golf ball hit by
the golf club during a flight on its trajectory.
2. The golf ball performance evaluation system according to claim
1, wherein the in-flight properties analyzing unit comprises a
radar transmitter-receiver unit that transmits radio waves towards
the golf ball and receives radio waves that are reflected back by
the golf ball.
3. The golf ball performance evaluation system according to claim
1, further comprising an elevation angle measuring unit for
measuring an elevation angle of a trajectory drawn by the golf ball
flying after having been hit by the golf club.
4. The golf ball performance evaluation system according to claim
2, further comprising an elevation angle measuring unit for
measuring an elevation angle of a trajectory drawn by the golf ball
flying after having been hit by the golf club.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a golf ball performance
evaluation system and more particularly to a golf ball performance
evaluation system for measuring and analyzing not only kinetic
properties of a golf ball immediately after the golf ball is hit by
a golf club but also kinetic properties of the golf ball which
continues to fly on its trajectory (flying path) to draw a
parabola.
[0003] 2. Description of the Related Art
[0004] conventionally, flying properties (flight properties) of a
golf ball are measured and analyzed by actually hitting the golf
ball with a golf club to obtain some properties of the golf ball
such as speed (initial velocity), angle (hitting angle), spin
amount and the like which result immediately after the golf ball is
hit, and when required, a trajectory and distance of the golf ball
so hit are calculated through simulation using the properties of
the golf ball obtained as described above (for example, refer to
JP-A-10-206451).
SUMMARY OF THE INVENTION
[0005] The properties of the golf ball measured by the aforesaid
conventional system immediately after the golf ball was hit are,
however, initial kinetic properties of the golf ball which resulted
within an extremely short distance or a flying distance of less
than 1 m after the golf ball was hit. Therefore, for example,
assuming that a distance from the golf ball hitting position to the
landing point is 210 m (about 230 yards), it has been difficult to
estimate the shape of the trajectory and the behavior of the golf
ball as far as the landing point from the initial kinetic
properties of the golf ball. In particular, it has been unable to
accurately grasp the behavior of the golf ball which is flying high
on its trajectory.
[0006] On the other hand, it is known that the flying properties of
a solid golf ball largely depend on mainly the repulsive properties
of a core portion and a cover portion which make up the golf ball
and the aerodynamic property attributed to dimples formed on the
cover. Based on an assumption that a golf ball having superior
flying properties flies to draw a trajectory which matches such
flying properties, it is necessary to grasp how the repulsive
properties based on physical properties of the golf ball
constituent materials and the aerodynamic property based on the
surface configuration including the arrangement of dimples affect
the kinetic properties of the golf ball resulting immediately after
it is hit and the kinetic properties of the golf ball which result
before and after a peak position of the trajectory as well as at
the peak position. To make this happen, the two types of kinetic
properties have needed to be analyzed simultaneously.
[0007] An object of the invention is to provide a golf ball
performance evaluation system which can evaluate the performance of
a golf ball accurately by continuously measuring kinetic properties
of the golf ball immediately after the ball is hit and kinetic
properties of the golf ball during a flight on its trajectory by
individual measuring units and analyzing outputted information.
[0008] According to an aspect of the invention, there is provided a
golf ball performance evaluation system including an initial
properties analyzing unit for measuring and analyzing kinetic
properties of a golf ball immediately after the golf ball is hit by
a golf club and an in-flight properties analyzing unit for
measuring and analyzing kinetic properties of the golf ball hit by
the golf club during a flight on its trajectory.
[0009] In the invention, in the initial properties analyzing unit,
as the kinetic properties of the golf ball resulting immediately
after the golf ball is hit, for example, initial velocity, hitting
angle (an upward angle relative to a horizontal line, leftward or
rightward angle relative to a reference line), backspin amount,
sidespin amount and the like are measured and analyzed.
[0010] In addition, in the invention, in the in-flight properties
analyzing unit, as the kinetic properties of the golf ball
resulting when flying on its trajectory, for example, speed of the
golf ball at an arbitrary position on the trajectory, angle of the
trajectory including hitting or ascending angle and descending
angle of the golf bail relative to the horizontal line, height of
the golf ball at an arbitrary position including a maximum height
from the horizontal like, leftward or rightward hitting angle of
the golf ball and leftward or rightward deviation amount (distance)
including a maximum deviation, various types of spins (backspin and
sidespin) of the golf ball during flight on its trajectory, flying
distance of the golf ball, flying time of the golf ball and the
liker are measured and analyzed.
[0011] According to the golf ball performance evaluation system of
the invention, it becomes possible to evaluate the performance of
the golf ball comprehensively and accurately by continuously
measuring, with respect to the golf ball which is hit to fly by the
golf club, the kinetic properties of the golf ball resulting
immediately after the ball is hit and the kinetic properties
resulting at an arbitrary position on the trajectory by the
individual measuring units and analyzing outputted information.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic perspective view of a golf ball
performance evaluation system according to an embodiment of the
invention;
[0013] FIG. 2 is a schematic front view of the same system with a
display unit thereof removed;
[0014] FIG. 3 is an explanatory diagram showing a trajectory of a
golf ball;
[0015] FIG. 4 is an operation explanatory diagram of the system
shown in FIG. 1;
[0016] FIG. 5 is a diagram showing a monitor screen of the system
shown in FIG. 1; and
[0017] FIG. 6 is a schematic diagram showing an example of a mark
provided on a surface of the golf ball.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Hereinafter, an embodiment of the invention will be
described with reference to the accompanying drawings, but the
invention is not limited to the embodiment below. FIG. 1 is a
schematic perspective view of a golf ball performance evaluation
system according to an embodiment of the invention, and FIG. 2 is a
schematic front view of the same system with a display unit thereof
removed.
[0019] In FIGS. 1 and 2, reference numeral 10 denotes an initial
properties analyzing unit. The initial properties analyzing unit 10
includes a sensor unit 12, a photographing unit 14 having two
cameras placed to align with each other substantially horizontally
in a direction in which a golf ball is hit to fly, and a properties
analyzing unit 16 for analyzing and displaying photographed
results. In addition, although not so illustrated, the sensor unit
12, the photographing unit 14 and the properties analyzing unit 16
are electrically connected. Additionally, in FIGS. 1 and 2,
reference numeral 20 denotes an in-flight properties analyzing
unit. The in-flight properties analyzing unit 20 includes a radar
transmitter-receiver unit 22 and a display unit 24, and although
not so illustrated, both the radar transmitter-receiver unit and
the display unit are electrically connected. Furthermore, an
elevation angle measuring unit 30 for measuring an elevation angle
of the golf ball hit can be used additionally in the system of the
embodiment.
[0020] Firstly, the initial properties analyzing unit 10 will be
described. In FIGS. 1 and 2, a golf ball is set on a tee 42. In
addition, the sensor unit 12 for detecting a passage of a head of a
golf club 44 which is swung downwards to hit the golf ball is
disposed to the rear of a target line of the golf ball 40. A
primary sensor 12a and a secondary sensor 12b which are made up of
an optical light emitting portion and light receiving portion are
set at an interval of m1 (about 70 mm) in the sensor unit 12. A
distance m2 between the secondary sensor 12b and the tee 42 is
about 40 mm.
[0021] In addition, in the photographing unit 14 of the initial
properties analyzing portion 10, two cameras are set transversely
to photograph the behavior of the golf ball at an extremely initial
part of a trajectory of the golf ball flying to draw a parabola
shown in FIG. 3. Namely, a primary camera 14a is set in a position
which is a distance m4 of 50 to 300 mm apart from the tee 42 and a
secondary camera 14b is set in a position which is a distance m5 of
60 to 250 mm apart from the primary camera 14a. CCD cameras having
a shutter speed of 1/10,000 to 200,000 of a second are preferably
used for those cameras, and electronic flashes 14c, 14d are also
preferably provided for the cameras, respectively (the flashes are
shown only in FIG. 2.).
[0022] Next, a measuring method used in the initial properties
analyzing unit 10 will be described using FIGS. 1 and 2 and an
operation diagram shown in FIG. 4. Firstly, when the primary sensor
12a and the secondary sensor 12b detect a passage of the head of
the golf club 44 which is swung downwards by the golfer, a passage
time t1 is detected and a head speed is measured from a
relationship between the distance m1 between both the sensors 12a,
12b and the time t1 so detected. Next, receiving a signal by the
secondary sensor 12b, a trigger output ST acts on the primary
camera 14a, the secondary camera 14b and the electronic flashes
therefor, The trigger output ST measures in advance a plurality of
head speeds to be applied, for example, and sets delay times t2
which correspond to these head speeds and a shutter interval t3
between both the cameras 14a, 14b. Images photographed by the
cameras 14a, 14b are displayed on a monitor screen 18 of the
properties analyzing unit 16.
[0023] Next, a golf ball initial kinetic properties analyzing
method will be described. The initial velocity of the golf ball is
measured based on a relationship between a time t3 taken for the
golf ball hit to pass by the primary cameral 14a and the secondary
camera 14b and the distance m5 between both the cameras 14a, 14b.
The hitting angle of the golf ball (a vertical direction relative
to the horizontal line), backspin amount and sidespin amount will
be measured as below.
[0024] FIG. 5 shows images of the golf ball displayed on the
monitor screen 18 of the properties analyzing unit 16 when the ball
is hit. An image of the golf ball resulting when the ball is
photographed from a side thereof by the primary camera 14a is
displayed in a first portion 60 of the monitor screen 18, while an
image of the golf ball resulting when the ball is photographed from
the same side thereof by the secondary camera 14b is displayed on a
second portion 62, and measured values are displayed in a third
portion 64. In this embodiment, a mark M of isosceles triangle is
imparted to a surface of the golf ball 40. The color of the mark M
is preferably black or a dark color likened thereto in order to
make the mark M prominent from the color (normally, white) of the
golf ball.
[0025] In the initial kinetic properties analyzing method of the
embodiment, with respect to the images displayed in the first
portion 60 and the second portion 62 of the monitor screen 18, the
external shape of the golf ball 40 which is shown as a white
portion is extracted from the background thereof which is shown as
a black area in the monitor screen 18 using a two-valued logic
method (white or black). Following this, the mark M (black) within
the external shape of the golf ball 40 which has been so extracted
is then extracted using the same two-valued logic method.
[0026] When the extracting process is completed, a principal axis
(an extension line containing the height) of the mark M is
obtained, and furthermore, a search is made vertically from the
principal axis so obtained to obtain a changing point where the
color changes from black to white. The retrieval of changing point
from black to white by the vertical search is carried out along the
principal axis, and straight lines which pass through
points/strings of these changing points or two oblique sides are
obtained from results of the retrieval. Following this, a base line
which intersects a median line of the two oblique sides at right
angles is set outside the black block (the mark M), and a search is
made from there towards the block side to obtain a base. When
obtaining the oblique sides and the base, it is good to use curve
fitting to obtain them in consideration of curving due to spherical
surface.
[0027] When a triangle or the mark M is set by the image processing
described above, three apexes are obtained from three sides, and a
first apex A1, a second apex A2 and a third apex A3 are determined.
Then, three-dimensional vectors of the first apex A1, second apex
A2 and third apex A3 when regarding the golf ball 40 as a unit ball
having a radius 1 are obtained from the images displayed in the
first portion 60 and the second portion 62 of the monitor screen
18, and a rotational axis vector of the golf ball 40 is obtained
based on a transition from the first portion 60 to the second
portion 62 of the monitor screen 18, whereby a vector operation of
the rotational axis vector and position vectors of the individual
apexes is carried out to obtain an revolution amount of the golf
ball. When the rotational axis vector and the revolution amount are
obtained, a backspin amount and a sidespin amount of the golf ball
40.
[0028] In addition, a vertical positional relationship between the
golf balls 40 displayed in the first portion 60 and the second
portion 62 of the monitor screen 18 is measured, so that an upward
hitting angle of the golf ball 40 can be obtained from a
relationship between the inter-camera distance m5 (a horizontal
distance) between the cameras 14a, 14b and the vertical positional
relationship so obtained. Furthermore, a leftward or rightward
deviation (a leftward or rightward hitting angle) of the golf ball
hit can be measured based on the magnitudes of the diameters of the
golf balls 40 displayed in the first portion 60 and the second
portion 62 of the monitor screen 18.
[0029] Next, a measuring method used in the in-flight properties
analyzing unit 20 will be described. The in-flight properties
analyzing unit 20 includes the radar transmitter-receiver unit 22
and the display unit 24. In this embodiment, the radar
transmitter-receiver unit 22 incorporates therein a transmitter
which transmits radio waves towards the golf ball 40 projected and
three receivers which receive radio waves which hit the golf ball
40 to thereby be reflected back therefrom. This radar
transmitter-receiver unit 22 can be set a distance m3 of about 2000
mm to the direct rear of the golf ball 40 on the tee 42. On the
other hand, the display unit 24 is electrically connected to the
radar transmitter-receiver unit 22 and has a data operating
function.
[0030] In this embodiment, to improve the reflection of radio waves
by the golf ball hit to fly and facilitate the detection of a
revolving state of the golf ball, a plurality of dimples 80 (five
dimples in this embodiment) are, as shown in FIG. 6, for example,
aligned in a straight line, and a metal-based paint 82 is applied
to interiors of these dimples 80, so that a mark 84 having a
superior radio wave reflecting property can be provided on the
surface of the golf ball. This mark 84 made by the application of
the metal-based paint can be provided in addition to the mark M of
isosceles triangle.
[0031] The radar transmitter-receiver unit 22 transmits radio waves
towards the golf ball 40 on the tee 42, as well as the golf ball 40
which is hit to fly and receives radio waves reflected by the
rectilinear mark 84 of the metal-based paint, whereby the position
of the golf ball, which varies every second, is measured with
passage of time along a trajectory 90 shown in FIG. 3 which
initiates from a golf ball setting position 92 where the golf ball
is set on the tee 42 and ends at a landing point 96 via points
including a point immediately after the golf ball is hit and a peak
position 94, thereby making it possible to calculate the speed of
the golf ball in an arbitrary position on the trajectory from the
initial velocity which results immediately after the golf ball is
hit to a speed thereof which results immediately before the golf
ball lands at the landing point 96.
[0032] In addition, prior to any of the measurements with respect
to the golf ball hit to fly, as shown in FIG. 3, the radar
transmitter-receiver unit 22 sets a horizontal line X on the field
independently and also sets a center line, thereby making it
possible to measure the angle of the trajectory which includes the
hitting angle and falling angle of the golf ball hit to fly
relative to the horizontal line X so set and the height of the golf
ball hit to fly in an arbitrary position on the trajectory which
includes a maximum height h thereof from the horizontal line X. On
the other hand, a leftward or rightward hitting angle of the golf
ball as a deviation from the center line set and a leftward or
rightward deviation amount (distance) including a maximum deviation
can be measured.
[0033] Furthermore, various types of spins (backspin and sidespin)
of the golf ball flying on its trajectory can be calculated by
detecting radio waves reflected back from the rectilinear mark 84
of the metal-based paint. In this case, the various types of spins
can be calculated correspondingly to various behaviors of the golf
ball on the trajectory. Furthermore, a flying time as well as a
distance d from the golf ball setting position 92 to the golf ball
landing point 96 can also be calculated.
[0034] The in-flight kinetic properties of the golf ball on the
trajectory measured and analyzed by the in-flight properties
analyzing unit 20 are displayed on a monitor screen 26 of the
display unit 24.
[0035] In this embodiment, the elevation angle measuring unit 30
shown in FIGS. 1 and 2 can be used as required. The elevation angle
measuring unit 30 incorporates therein a camera, and the camera is
preferably set substantially at the position of the tee with
respect to the direction of the target line of the golf ball and
substantially at a position equal to the height of the eyes of a
human being with respect to the vertical direction.
[0036] The elevation angle measuring unit 30 can start
photographing by making use of a trigger signal in the form of a
sound generated when the golf ball is hit to fly or the trigger
output ST which was described with respect to the measuring method
used in the initial properties analyzing unit. The image of the
golf ball hit to fly which changes every second is converted into
an electric signal and is then sent to a display unit (not shown)
which incorporates therein an operation unit or a personal
computer, whereby not only the trajectory is displayed on the
monitor screen but also an elevation angle (an ascending angle of
the golf ball hit to fly relative to the horizontal line
imaginarily drawn at the height of the camera or the height of the
eyes of the human being), a leftward or rightward angle (deviation)
relative to the center line, an ascending angular velocity and a
descending angular velocity of the golf ball on the trajectory are
calculated from photographed image signals and then displayed on
the screen.
[0037] Thus, the data obtained by the initial properties analyzing
unit 10, the in-flight properties analyzing unit 20 and the
elevation angle measuring unit 30 are accumulated in the personal
computer, and data necessary to analyze golf balls and golf clubs
are processed into an easily usable form to be stored therein.
* * * * *