U.S. patent application number 10/057858 was filed with the patent office on 2003-02-27 for accurate, multi-axis, computer-controlled object-projection machine and manufacturing process employing the accurate, multi-axis, computer-controlled object-projection machine.
Invention is credited to Crews, Doug A., Richings, Richard J..
Application Number | 20030040381 10/057858 |
Document ID | / |
Family ID | 26936673 |
Filed Date | 2003-02-27 |
United States Patent
Application |
20030040381 |
Kind Code |
A1 |
Richings, Richard J. ; et
al. |
February 27, 2003 |
Accurate, multi-axis, computer-controlled object-projection machine
and manufacturing process employing the accurate, multi-axis,
computer-controlled object-projection machine
Abstract
Multiple axes are employed to impart predetermined velocities
and rotational components to the projected object. Projection of
the object may be synchronized with a displayed video image to
simulate the throwing of an object. The
accurate-automated-multi-axis machine for projecting objects may be
employed as an integral component in a projectable object
manufacturing process.
Inventors: |
Richings, Richard J.;
(Shoreline, WA) ; Crews, Doug A.; (Seattle,
WA) |
Correspondence
Address: |
ROBERT W. BERGSTROM
HENDRICKS & LEWIS
Suite 2675
999 Third Avenue
Seattle
WA
98104
US
|
Family ID: |
26936673 |
Appl. No.: |
10/057858 |
Filed: |
January 23, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10057858 |
Jan 23, 2002 |
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09570977 |
May 15, 2000 |
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6443140 |
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09570977 |
May 15, 2000 |
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09244608 |
Feb 4, 1999 |
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6082350 |
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Current U.S.
Class: |
473/415 ;
473/451; 473/569 |
Current CPC
Class: |
A63B 69/0024 20130101;
A63B 2243/0066 20130101; A63B 2225/30 20130101; A63B 2069/0008
20130101; A63B 2069/401 20130101; A63B 47/00 20130101; A63B 69/38
20130101; A63B 69/406 20130101; A63B 69/004 20130101 |
Class at
Publication: |
473/415 ;
473/451; 473/569 |
International
Class: |
A63B 067/00; A63B
039/00; A63B 069/00 |
Claims
1. A baseball-manufacturing process for manufacturing
aerodynamically reliable baseballs, the process including:
providing a baseball-projection machine that can be controlled to
project baseballs at specific, desired speeds and rotational
directions and velocities to impact a target ninety feet from the
baseball-projection machine accurately; manufacturing sets of
baseballs with precise tolerances for physical characteristics and
parameters, varying one or more characteristics or parameters
within each set; projecting the sets of baseballs using the
baseball-projection machine in order to determine the magnitude of
the effect of varying the one or more parameters or characteristics
on the aerodynamic reliability of the baseballs within each set of
baseballs; selecting from among the parameters and characteristics
varied in the sets of baseballs a subset of characteristics and
parameters that have the most effect on the aerodynamic reliability
of the baseballs; and designing a manufacturing process in which
the selected characteristics and parameters are carefully
controlled within desired tolerance ranges in order to produce
aerodynamically reliable baseballs.
2. A baseball manufactured by the baseball-manufacturing process of
claim 1.
3. A projectable object-manufacturing process for manufacturing
aerodynamically reliable projectable objects, the process
including: providing a projectable-object-projection machine that
can be controlled to project projectable objects at specific,
desired speeds and rotational directions and velocities to
accurately impact a target; manufacturing sets of projectable
objects with precise tolerances for physical characteristics and
parameters, varying one or more characteristics or parameters
within each set; projecting the sets of projectable objects using
the projectable object-projection machine in order to determine the
magnitude of the effect of varying the one or more parameters or
characteristics on the aerodynamic reliability of the projectable
objects within each set of projectable objects; selecting from
among the parameters and characteristics varied in the sets of
projectable objects a subset of characteristics and parameters that
have the most effect on the aerodynamic reliability of the
projectable objects; and designing a manufacturing process in which
the selected characteristics and parameters are carefully
controlled within desired tolerance ranges in order to produce
aerodynamically reliable projectable objects.
4. The projectable object manufacturing process of claim 3 wherein
the projectable object is selected from a set of projectable
objects that include: baseballs; tennis balls; golf balls;
footballs; soccer balls; bowling balls; lacrosse balls;
basketballs; ping pong balls; and volleyballs.
5. A projectable object manufactured by the projectable
object-manufacturing process of claim 3.
6. A projectable object manufactured by the projectable object
manufacturing process of claim 5 wherein the projectable object is
selected from among a set of projectable objects that include:
baseballs; tennis balls; golf balls; footballs; soccer balls;
bowling balls; lacrosse balls; basketballs; ping pong balls; and
volleyballs.
Description
CROSS REFERENCE
[0001] This application is a continuation-in-part of pending U.S.
Ser. No. 09/570,977, filed May 15, 2000, which is a continuation of
U.S. Ser. No. 09/244,608, filed Feb. 4, 1999, which is now U.S.
Pat. No. 6,082,350, issued Jul. 4, 2000.
TECHNICAL FIELD
[0002] The present invention relates to throwing machines and, in
particular, to an accurate object throwing machine having multiple
axes that are controlled by a computer system to throw an object
from a predefined release point with a predefined initial velocity,
a predefined initial trajectory, and two predefined components of
rotational motion.
BACKGROUND OF THE INVENTION
[0003] Professional baseball, through attendance fees, broadcast
rights, and various marketing activities, generates enormous annual
revenues. However, because of the high salaries paid to
professional baseball players and the high cost of stadiums and
training facilities, baseball is a business of relatively close
margins. In order to maintain and increase revenues from game
attendance and from televised broadcasts, it is vital to maintain
high levels of interest and excitement of baseball fans. Although
low-scoring pitching duels may be the delight of baseball
connoisseurs, fans are generally most interested and excited in
games that feature relatively large numbers of base hits and home
runs.
[0004] Successfully hitting a baseball pitched by a professional
baseball pitcher is considered by many to be the single most
difficult task undertaken by an athlete in professional sports. The
speed of a pitched baseball, as it crosses home plate, may vary
from between 60 and 70 mph to over 90 mph. The baseball may be
released from any point within a relatively large area, depending
on the height and stance of a pitcher and the type of pitch that is
being thrown. A thrown baseball may exhibit any one of a large
number of different, aerodynamically induced trajectories that
depend on the orientation of the seams of the baseball with respect
to the translational and rotational motions of the baseball, the
initial velocity of the baseball, and the orientation of the
rotational motion of the baseball with respect to the translational
motion of the baseball. Because of the short travel time of a
thrown baseball between the release point and home plate, on the
order of between 4 and 5 tenths of a second, because of the
relatively slow response times of a batter following the visual
perception of the release and initial trajectory of a pitched
baseball, and because of the large number of different,
aerodynamically induced trajectories that a thrown baseball may
follow, a batter has only milliseconds in which to either estimate
the height and orientation with which a thrown baseball transverse
a volume of space above home plate known as the strike zone and
begin to swing the bat to meet the baseball or to include that the
trajectory of the baseball will not intersect the strike zone and
decline to swing the bat. Advances or delays of as little as 5
milliseconds in the timing of the initiation of the swing that
would, if correctly timed, result in a home run, may result in a
foul ball to the left-hand side of the field or a foul ball to the
right-hand side of the field. Slight dislocations of the point of
contact between the bat and the pitched baseball from the optimal
point of contact can result in erratic pop-ups or foul balls.
[0005] Because fan enthusiasm depends, to a large extent, on the
ability of batters to hit pitched baseballs, and because hitting
pitched baseballs requires hand-eye coordination skills close to
the limit of human ability, training of professional baseball
players to consistently hit baseballs pitched by professional
baseball pitchers is a vital and difficult component of a
professional baseball training program. One effective approach to
train batters to hit professional pitched baseballs would be to
expose the batter to professional pitchers for many hours each day.
However, the ability to pitch baseballs accurately, at high speeds,
and with varying trajectories, is also a rare skill. In addition,
pitching baseballs at the highest skill levels is an extremely
physically demanding undertaking. Because of the high salaries paid
to professional baseball pitchers, because of the relatively short
duration in which a baseball pitcher can pitch baseballs at high
skill levels without incurring an injury, and because of the
relatively large number of pitches that need to be thrown to each
batter in order to train that batter, it is impractical to use
professional baseball pitchers to train batters.
[0006] As an alternative to using professional baseball pitchers,
baseball teams may employ semi-professional or amateur pitchers for
practice sessions. However, using semi-professional or amateur
pitchers may also be expensive, and, most importantly,
semi-professional and amateur pitchers cannot throw the baseball
with the speeds, accuracies, and varying trajectories with which
professional pitchers pitch the baseballs during games. For these
reasons, baseball teams have employed a number of different
pitching machines for repetitive batting practice.
[0007] Various types of pitching machines have been designed,
manufactured and proposed. In one type of pitching machine, shown
in FIG. 1, a baseball 102 is tethered by a line or cable 104 to a
vertical rotating shaft 106 spun by an electric motor 108. The ball
travels in a circular path within a horizontal plane, each
revolution representing a pitch. In general, such devices poorly
simulate a thrown baseball because the circular trajectory of the
ball does not resemble the trajectory of a pitched baseball.
[0008] A large variety of different devices for projecting a
baseball have been employed. Such devices may be placed at roughly
the same distance from a practicing batter as the distance between
a batter and the normal release point of a baseball pitcher. A
number of different propulsion mechanisms have been used in these
projecting devices, including pneumatic propulsion, electromagnetic
acceleration, and spring driven lever arms. Although far better
than the pitching machine displayed in FIG. 1, these various types
of projecting pitching machines have also proved inadequate. In
general, they are not able to faithfully replicate the motion of a
baseball as thrown by a baseball pitcher. Furthermore, these
devices are generally quite inaccurate, as well as unsafe due to
the risk of injury to the batter. While a professional baseball
pitcher can routinely pitch a baseball through the front face of
the strike zone, a cube less than two feet on a side, the pitching
machines pitch with much greater variation. As a result, a batter
practicing against such machines naturally tends to adopt a more
careful and hesitant attitude than the batter would adopt against a
human pitcher. More problematic, these pitching machines generally
pitch baseballs at slower speeds than a professional baseball
pitcher, and generally do not pitch real baseballs. Pitching of
real baseballs is problematic because the currently-available
machines have no way of orienting the seams of the baseball and,
without such orientation, the trajectory of the baseball becomes
quite erratic because of aerodynamic affects.
[0009] A far more successful type of pitching machine, produced by
a number of pitching machine manufacturers, including The Jugs.TM.
Company, employs two counter-rotating rubber-tired wheels to propel
a baseball towards a batter as well as to impart a rotational spin
on the baseball. FIG. 2 illustrates a Jugs-type pitching machine. A
human operator 202 places a baseball 204 into a mechanical feeder
(not shown) through which the baseball rolls into a narrow space
between the two counter-rotating rubber pneumatic tire and wheel
assemblies that include wheels 206 and 208. The counter-rotating
wheels 206 and 208 are independently driven by electric motors 210
and 212. The counter-rotating wheels rotate at speeds up to 3,000
rpm. The ball is briefly pinched between the wheels and then
expelled at speeds that can approach 90 mph. By adjusting the rate
of spin of one wheel with respect to the other, so that the two
counter-rotating wheels rotate at slightly different speeds, a ball
can be expelled from the device with a rotation, either forward or
backward, in the plane in which the two counter-rotating wheels
lie. Moreover, as shown in FIG. 3, the plane of the
counter-rotating wheels can be tilted in order to alter the
trajectory of the ball. In FIG. 3, for example, the ball follows a
curved path between the Jugs machine and the batter because of a
tilted spin imparted to the ball by the tilted counter-rotating
wheels. The Jugs machine can be adjusted along a number of
different axes. For example, the mechanism may be rotated with
respect to a vertical axis in order to adjust the initial
horizontal trajectory of the pitched ball. The assembly can be
vertically adjusted about a horizontal axis to vary the angle at
which a ball is pitched with relation to the ground. These vertical
and horizontal adjustments together describe the initial
translational trajectory of the baseball. Because the
counter-rotating wheels are driven by separate electrical motors,
their relative rotational speeds can be adjusted to impart
different degrees of spin in both the forward and backward
directions to the ball.
[0010] While a vast improvement over the previously described
devices, the Jugs machine nonetheless falls far short of the
capabilities of a human baseball pitcher. First, the Jugs machine
does not accurately pitch real baseballs because the Jugs machine
cannot orient the seams of a real baseball reliably, and thus
cannot control the aerodynamically induced motion of the baseball.
Instead, a dimpled plastic ball is normally used. Second, there are
additional rotational motions that can be imparted to the baseball
by a human pitcher that the Jugs machine cannot reproduce. The Jugs
machine does not have enough controllable axes in order to
reproduce a human thrown baseball. Finally, the Jugs machine does
not reproduce the visual appearance of a human baseball pitcher,
including varying release points for varying pitches. The release
point can be adjusted on a Jugs machine by raising and lowering the
counter-rotating wheel assembly, but this operation requires a
rather lengthy period of time and a rather lengthy period of
recalibration.
[0011] In order to simulate a live human pitcher, manufacturers
have attempted to combine projection of a video image of a baseball
pitcher with baseball pitching machines of various types, most
commonly, a Jugs-type baseball pitching machine. FIG. 4 illustrates
a live-motion, video-image pitching machine system. A live-motion
image of a baseball pitcher 402 is projected onto a screen 404. At
the point in time at which the image of the baseball pitcher
releases the baseball, a baseball is ejected from a small
stationary port 406 in the plane of the projection screen 404. In
general, these systems have been rather crudely implemented and do
not reproduce the timing and appearance of a human pitcher. First,
as with the other above mentioned pitching machines, these systems
generally do not pitch real baseballs, but instead pitch dimpled
plastic baseballs, with the same lack of ability to reproduce the
actual motion of pitched baseballs as inherent in all the above
described pitching machines. Moreover, the release point 406 is
fixed on the screen, whereas a human pitcher releases the balls at
varying locations on a release-point plane at various distances
from the batter, depending on the different types of pitches that
are being thrown and on the physical characteristics of the
pitcher. Finally, all of these systems place the projection screen
closer to the batter than the 60-foot distance that normally
separates a batter from a human pitcher, generally from as little
as 20 feet up to a maximum of 50 feet. To make up for the shortened
distance, the ball is thrown at slower speeds. However, the visual
effect produced by these systems is much different that the visual
effect produced by a human pitcher throwing at normal speeds and by
the aerodynamic motion of a pitched baseball.
[0012] Because of the increasingly thin profit margins in the
baseball business, the need for improving professional baseball
batting is becomingly increasingly important. Currently available
baseball pitching machines cannot closely reproduce the motions of
baseballs pitched by human pitchers. Currently available baseball
pitching systems cannot reproduce the visual appearance of a human
pitcher, nor can they reproduce the varying release points and the
motions of human pitched baseballs. For these reasons, a need has
been recognized for a baseball pitching machine that can faithfully
reproduce the motions and trajectories of pitched baseballs and
that can faithfully reproduce the appearance of a human pitcher. In
addition, for many of the above-described reasons, object
projecting machines configured to repeatedly and faithfully
reproduce thrown and batted objects are equally desirable for
simulating other aspects of baseball and other types of sports,
including tennis, hockey, martial arts, football, ping-pong, and
badminton, and may have additional industrial applications.
SUMMARY OF THE INVENTION
[0013] One embodiment of the present invention is a multi-axis,
servo-controlled baseball pitching machine ("BPM"). A full-motion
image of a baseball pitcher is displayed on a vertical projection
screen at the front of the BPM. The moving image of the baseball
pitcher simulates the positions and movements of a baseball
pitcher. Various moving images can simulate a variety of different
types of pitches pitched by any number of different baseball
pitchers. At the point in time that the baseball is released from
the simulated pitcher's hand, a physical baseball is projected
through the projection screen, from the position of the release
point of the baseball portrayed in the projected image, towards a
defined position relative to a human batter. Thus, the BPM of one
embodiment of the present invention visually simulates the position
and motions of various baseball pitchers throwing different types
of pitches and projects a baseball towards the batter with a
predetermined initial speed and with a predefined trajectory that
faithfully reproduces the type of pitch being thrown by the
simulated baseball pitcher.
[0014] The BPM features a dynamic release point, or port, that can
be positioned anywhere within a large portion of the projection
screen in order to coincide in time and position with the release
of the baseball by the simulated pitcher. The dynamic port operates
as a shutter that is opened for a very short period of time to
allow a baseball to pass through the projection screen. The action
of the shutter is not visible to the batter, since it is actuated
in less than {fraction (1/25)}th of a second, below the visual
acuity threshold for humans.
[0015] The baseball is gripped by a gripper component and
horizontally translated between two cylindrically shaped
counter-rotating flywheels. The cylindrical surface of the two
flywheels is coated with a compressible material that grips the
baseball through frictional forces. The rotational momentum of the
counter-rotating flywheels is then instantaneously imparted to the
baseball when the gripper component forces the baseball between the
two counter-rotating flywheels and projects it at a high speed
towards home plate in the direction of a horizontal axis between
the two counter rotating flywheels. The speed of the ball is
controlled by the rotational speed of the counter-rotating
flywheels, each driven by an electrical servomotor. A rotational
spin either in a clockwise or a counterclockwise direction in a
plane passing through and bisecting both counter-rotating flywheels
can be imparted to the baseball by rotating the two
counter-rotating flywheels at different speeds. The angle of the
spin with respect to the vertical can be adjusted by rotating both
flywheels about a projection axis passing between the two
flywheels, orthogonal to a line segment between the centers of the
two flywheels and coplanar with the plane passing through and
bisecting both counter-rotating flywheels, along which the baseball
is initially projected. When rotation of the flywheels about the
projection axis occurs at the time that the baseball is projected
from between the flywheels, an additional spin can be imparted to
the baseball in a plane orthogonal to the projection axis passing
between the two flywheels.
[0016] The flywheels and the servomotors driving the flywheels are
mounted in an assembly that can be horizontally and vertically
translated with respect to the projection screen, thus placing the
release point of the baseball at any point within in a planar area
coincident with, and bounded by, the plane of the projection
screen. In addition, the assembly can be driven by additional
servomotors to rotate about a pivot in the horizontal direction and
to rotate about a pivot in the vertical direction in order to
orient the projection axis within an imaginary cone perpendicular
to the projection screen and opening out and away from the
projection screen from the release point of the baseball in the
direction of projection of the baseball.
[0017] The reflective surface of the projection screen comprises
three flexible sheets. A first flexible sheet is attached to the
left side of the assembly in which the counter-rotating flywheels
are mounted and is taken up by a vertically-mounted, spring-loaded
take-up reel on the left side of the baseball machine. Similarly, a
second flexible reflective sheet is attached to the right side of
the assembly in which the flywheels are mounted and is taken up by
a vertically mounted, spring-loaded take-up reel on the right side
of the baseball machine. A third reflective, flexible sheet with a
slot, or aperture, is held between lower and upper
horizontally-mounted, electrical servo operated reels that are
positioned below and above the assembly in which the flywheels are
mounted and that are translated horizontally with respect to the
projection screen along with the assembly in which the flywheels
are mounted. By moving the aperture in the third flexible sheet to
a location coincident with the projection axis at the time that the
baseball is projected between the two flywheels, a small,
shutter-like opening briefly appears in the surface of the
projection screen in order to allow the baseball to pass through
the projection screen. The speeds of the two counter-rotating
flywheels, the release point of the baseball, the initial direction
at which the baseball is projected away from the projection screen,
and the angle of the plane bisecting the two counter-rotating
flywheels with respect to the projection axis can all be controlled
and adjusted by computer control of electrical servomotors to
faithfully reproduce the trajectories of various types of baseball
pitches, including the fastball, the curveball, the knuckleball,
and the slider. Moreover, the various types of pitches can be
coordinated with the projected images of a baseball pitcher to
simulate pitching of the baseball by any number of different
baseball pitchers. Finally, the trajectory with which the baseball
passes through the strike zone can be accurately predetermined by
computer control of the electrical servomotors to within a radius
of two inches from a desired trajectory when the baseball is
projected from a distance of 60 feet.
[0018] Modification of certain components of the object-projection
machine of the present invention can be made to produce a tennis
ball serving machine, a martial arts weapons throwing machine, a
football passing machine, and other types of sports simulators. The
object-projection machine may also find use in industrial
simulators, test equipment, and mass conveyance devices. In
addition, the object-projection machine may be employed as an
integral component of a projectable object manufacturing
process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates one type of currently-available pitching
machine.
[0020] FIG. 2 illustrates a variety of different devices for
projecting a baseball.
[0021] FIG. 3 illustrates a Jugs.TM. pitching machine.
[0022] FIG. 4 illustrates a live-motion video-image pitching
machine system.
[0023] FIG. 5 illustrates the appearance of the BPM as viewed from
an observation point somewhat behind home plate.
[0024] FIG. 6 shows the BPM as seen from an observation point
behind the side of the BPM opposite from the vertical projection
screen.
[0025] FIG. 7 illustrates additional details of the vertical
projection screen of the BPM.
[0026] FIG. 8 illustrates seven additional mechanical axes of the
BPM.
[0027] FIGS. 9 and 10 illustrate the main frame, X-axis frame, and
Z-axis carriage of the BPM.
[0028] FIGS. 11A-C illustrate the roller and roller track mechanism
of the Z-axis carriage.
[0029] FIG. 12 is an exploded view of the vertical projection
screen.
[0030] FIG. 13 is a front view of the I-axis projection screen
mounted to the X-axis frame.
[0031] FIGS. 14A-B show a sectional view and an edge-on cross
section of a flywheel.
[0032] FIG. 15 is an exploded view of the flywheel drive
assembly.
[0033] FIG. 16 shows an exploded view of the flywheel housing
assembly.
[0034] FIG. 17 shows the fully assembled flywheel housing
assembly.
[0035] FIG. 18 illustrates the H and J-axes assembly.
[0036] FIG. 19 shows the fully assembled H and J-axes assembly in a
retracted position.
[0037] FIG. 20 shows the fully assembled H and J-axes assembly with
extension of the extensible arm of the electrical cylinder.
[0038] FIG. 21 shows an exploded view of the baseball gripper
assembly.
[0039] FIG. 22 shows an exploded view of the W-axis carriage as
seen from a vantage point near the vertical projection screen
looking toward the H and J-axes assembly.
[0040] FIG. 23 shows a partially exploded illustration of the
W-axis carriage seen from an observation point behind the H and
J-axes assembly looking forward towards the vertical projection
screen.
[0041] FIG. 24 is a horizontal plane view of the Y-axis carriage
and the W-axis carriage looking down the W-axis.
[0042] FIG. 25 is a horizontal plane view of the Y-axis carriage
and the W-axis carriage looking down the W-axis with the W-axis
carriage rotated with respect to the W-axis.
[0043] FIG. 26 illustrates the Y-axis carriage.
[0044] FIG. 27 shows the Y-axis carriage in a horizontal
position.
[0045] FIG. 28 illustrates the Y-axis carriage rotated downward
about the Y-axis.
[0046] FIG. 29 illustrates the Z-axis carriage.
[0047] FIG. 30 is a sectional view of the Y-axis carriage.
[0048] FIG. 31 shows a cross section of the W-axis carriage looking
down the W-axis from above the BPM.
[0049] FIGS. 32 and 33 illustrate rotation of the flywheel housing
about the G-axis.
[0050] FIG. 34 illustrates the electrical and computer control of
the BPM.
[0051] FIG. 35 is a flow control diagram illustrating the top level
BPM control program.
[0052] FIG. 36 is flow control diagram for the routine "pitch."
[0053] FIG. 37 is a flow control diagram of the calculation routine
called by the routine "pitch."
[0054] FIG. 38 illustrates an electrical servomotor operation
timeline.
[0055] FIG. 39 is a flow control diagram of the projection routine
called by the routine "pitch."
DETAILED DESCRIPTION OF THE INVENTION
[0056] One embodiment of the present invention is a baseball
pitching machine ("BPM") for use in baseball batting practice. FIG.
5 illustrates the appearance of the baseball pitching machine as
viewed from an observation point somewhat behind home plate. A
full-motion video image of a baseball pitcher 502 is projected onto
a vertical projection screen 504 that comprises the forward-facing
surface of the BPM 506. The image of the baseball pitcher 502 is
projected onto the projection screen 504 from a video image
projector 508. As an image of a baseball is released from the hand
of the projected image of the baseball pitcher 502, a dynamically
relocatable shutter 510 opens for an instant to allow a real
baseball to be projected from the BPM 506 toward a point in space
512 above home plate 514. The BPM 506 features computer-controlled,
multi-axis electrical servomotor control of a number of mechanical
components within the BPM that provide the BPM with the ability to
impart a precisely-defined initial velocity and initial trajectory
to the baseball as well as to impart several rotational spin
components to the baseball in order to simulate the type of pitch
thrown by the baseball pitcher whose image is displayed on the
projection screen 504. For example, the BPM can accurately simulate
a fastball pitch, a slider pitch, a curveball pitch, a knuckleball
pitch, and various more complex hybrid pitches. Furthermore, the
BPM can be calibrated in order to precisely target the baseball to
a selected point within a space 512 located above home plate
514.
[0057] FIG. 6 shows the BPM as seen from an observation point
behind the BPM. Major components of the baseball pitching machine
visible in FIG. 6 include: (1) a main frame 602 comprising twelve
members positioned along the edges of a rectangular solid and
joined at 90.degree. angles; (2) a rectangular X-axis frame 604,
having a top horizontal support 606 and lower horizontal support
608 affixed to an upper horizontal member 610 and a lower
horizontal member 612 of the main frame 602 via a system of rollers
(not shown) to allow the X-axis frame to move horizontally across
the plane of the vertical projection screen 614 (504 in FIG. 5);
(3) a Z-axis carriage 616 affixed to horizontal members 618 and 620
of the X-axis frame via a system of rollers (not shown) to allow
the Z-axis carriage to move in a vertical direction within the
X-axis frame; and (4) a number of baseball-projecting and
initial-trajectory-determining components 622 mounted within the
Z-axis carriage 616. The horizontal position of the X-axis frame
604 and the vertical position of the Z-axis carriage 616 together
determine an x, z Cartesian position of the release point of a
baseball with respect to the surface of the vertical projection
screen 614.
[0058] FIG. 7 illustrates additional details of the vertical
projection screen of the BPM. The vertical projection screen 702
comprises three separate flexible reflective sheets 704, 706, and
708. The left-hand sheet 704 is vertically attached to the X-axis
frame 705 (vertical attachment not shown) and extends across the
face of the BPM to a vertically mounted, spring-loaded
take-up/supply reel 710. The right-hand sheet 706 is vertically
attached to the X-axis frame 705 (vertical attachment not shown)
and extends across the face of the BPM to a vertically-mounted,
springloaded take-up/supply reel 712. Both vertically-mounted,
spring-loaded, take-up/supple reels are supplied by Milwaukee
Protective Covers, Inc., of Milwaukee, Wis. as part number
70-3-PN-11: the same type of reels are available from other
manufacturers of roll-up covers. The multiple internal springs in
the reels generate a band tension of 38.4 pounds-force on the sheet
to maintain a smooth and flat appearance to the user.
[0059] As the X-axis frame 705 moves horizontally across the face
of the BPM in a leftward direction, the left-hand take-up/supply
reel 710 reels in the left-hand hand flexible sheet 704 while, at
the same time, the right-hand take-up/supply reel 712 feeds out the
right-hand flexible sheet 706. Conversely, when X-axis frame 705
moves across the face of the BPM in a rightward direction, the
left-hand take-up/supply reel 710 feeds out flexible sheet 704
while the right-hand take-up/supply reel 712 reels in flexible
sheet 706. The third flexible reflective sheet 708 is mounted
between two horizontally-mounted, servo-motor-controlled
take-up/supply reels 716 and 718 that provide for vertical motion
of the third flexible sheet 708. All three reflective, flexible
sheets are constructed of one or more of the following materials,
available from manufacturers of elastomers and textiles worldwide,
in a thickness of 16 thousandths of an inch up to 32 thousandths of
an inch: Neoprene.RTM., cloth-inserted
[0060] EPDM (ethylene propylene diene monomer)
[0061] Hypalon
[0062] SBR (styrene butadiene rubber)
[0063] White Nitrile.RTM. FDA sheet (food grade Neoprene.RTM. plus
Nitrile.RTM. rubber coated polyamid)
[0064] Viton.RTM. (fluoro elastomer)
[0065] Fluorosilicone
[0066] Cloth, coated or impregnated with rubber or
Teflon.degree.
[0067] The two horizontally-mounted servo-motor-controlled
take-up/supply reels 716 and 718 and the third flexible sheet 708
together compose the I-axis. The third flexible sheet 708 includes
a rounded slot-like aperture 720 that can be quickly passed over
the release point 722 through which a baseball is projected. Thus,
motion of the aperture 720 across the release point 722, controlled
by the servo-motor-controlled take-up/supple reels 716, 718,
provides a shutter that exposes the release point 722 for a short
time interval during which the baseball is projected through the
release point. Otherwise, the aperture 720 is positioned either
above or below the release point over an opaque, reflective surface
affixed to the X-axis frame 705 so that, from a distance, the
entire vertical projection screen 702 appears to be uniformly
colored and uniformly reflective. This is actually accomplished by
the two Z-axis mask assemblies in addition to the faceplate 928
shown in FIG. 9.
[0068] The BPM is intended to simulate to a batter, as accurately
as possible, the environment of a baseball game in which the batter
is practicing to perform. To this end, the BPM can be augmented
with audio speakers to reproduce the audio environment which a
batter will likely encounter, including crowd noises and other
sounds particular to various ballparks at various times of day. The
loudspeaker announcement of the batter's name, for example, may be
reproduced to add realism and immediacy to the simulation. In
addition, the colors of the image of the baseball pitcher projected
on the vertical projection screen can be tuned to simulate, as
closely as possible, the colors of the background behind the BPM,
so that the BPM blends with the setting in which if is located, or,
conversely, so that the pitcher appears to the batter as closely as
possible to the anticipated appearance of the pitcher in an
upcoming venue.
[0069] FIG. 8 illustrates seven additional mechanical axes of the
BPM. In FIG. 8, the Z-axis carriage 802 (616 in FIG. 6), along with
additional projection and trajectory determining components
attached to the Z-axis carriage 802, is shown from an observation
point behind the vertical projection screen (not shown). A Y-axis
carriage 804 is mounted to the Z-axis carriage 802 via two pins 806
(second pin not shown) and a gear and electrical servo-motor
interface below the Y-axis carriage (not shown). The Y-axis
carriage 804, comprising a rectangular base member 808 affixed to a
rectangular front member 810, thus pivots, under electrical
servo-motor control, about an imaginary Y-axis that runs in a
horizontal direction through the centers of the two pins 806
(second pin not shown). Rotation of the Y-axis carriage about the
imaginary Y-axis determines the elevation component of the initial
trajectory of the baseball projected by the BPM. In other words,
the rotational position of the Y-axis carriage selects the angle of
the initial trajectory of the baseball with respect to the
horizontal plane of the ground. A W-axis carriage 812 is mounted
within the Y-axis carriage 804 via two vertical pins 814 (lower pin
not shown) coincident with an imaginary vertical W-axis and via a
fixed sector gear 816 enmeshed with a gear 818 directly attached to
the power shaft of an electrical servomotor 820. The electrical
servomotor 820 controls rotation, within a limited angular range,
of the W-axis carriage about the imaginary W-axis. The rotational
position of the W-axis carriage determines the windage component of
the initial trajectory of the baseball. In other words, the
position of the W-axis carriage with respect to the W-axis defines
a windage angle in a horizontal plane orthogonal to the vertical
plane of the projection screen 822 with respect to the projection
axis, an imaginary line describing the initial trajectory of a
baseball from the BPM. Thus, the rotational position of the Y-axis
carriage with respect to the imaginary Y-axis and the rotational
position of the W-axis carriage with respect to the imaginary
W-axis together determine the initial trajectory of the baseball as
it is projected through the vertical projection screen, or, in
other words, the orientation of the flywheel housing assembly with
respect to the vertical projection screen.
[0070] The baseball 824 is held by a gripper component 826 mounted
on the arm 828 of an electrical cylinder 830. The arm of the
electrical cylinder 828 can be linearly extended and retracted
along an imaginary H-axis coincident with the longitudinal axis of
symmetry of the electric cylinder arm 828. The electrical cylinder
830 is mounted to a horizontal gear 832 enmeshed with a gear 834
attached to the shaft of an electrical servomotor 836. The
electrical cylinder can thus be rotated in a horizontal plane about
an imaginary J-axis that passes through the center of the gear 832.
Thus, the electrical cylinder can be rotated in either direction
away from the position of electrical cylinder 830 shown in FIG. 8
for easy loading of the baseball 824 into the gripper component
826, and then rotated back into the position of the electrical
cylinder 830 shown in FIG. 8 in preparation for projection of the
baseball towards a target.
[0071] Baseball projection is accomplished by feeding the baseball,
via extension of the electrical cylinder 830, in between the two
counter-rotating flywheels 838 and 840. The baseball is
frictionally gripped by compressible circumferential belts bonded
to the cylindrical sides of the flywheels and expelled at high
speed along the projection axis, also called the "G-axis." The
flywheels are directly attached to axles coupled to the power
shafts of two horizontally mounted electrical servomotors 842 and
844. Each axle is mounted by two bearing mounts 846 and 848 (two
bearing mounts not shown) affixed to the two sides of a flywheel
housing 850. An imaginary E-axis is defined as being coincident
with the line of symmetry passing through the upper electrical
servomotor shaft and an imaginary F-axis is defined as coincident
with the line of symmetry passing through the lower electrical
servomotor shaft. The flywheel housing 850, along with the
flywheels 838 and 840 and the gripper component 826, can be rotated
about the G-axis by an electrical servomotor 852.
[0072] Table 1, below, summarizes the various axes illustrated in,
and described with respect to, FIGS. 6-8.
1TABLE 1 ADDS OPERATION ENERGY TO AXIS TYPE OF DURING THROWN LETTER
FUNCTION MOTION RELEASE BALL E UPPER FLYWHEEL ROTARY YES YES F
LOWER FLYWHEEL ROTARY YES YES G ROTATION OF ROTARY NO/YES NO/YES
PITCHING DATUM H FIRING LINEAR YES YES I SHUTTER DRIVE ROTARY YES
NO J RELOADING ROTARY NO NO W WINDAGE ROTARY NO NO X HORIZONTAL
RELEASE LINEAR NO NO POINT Y ELEVATION ROTARY NO NO Z VERTICAL
RELEASE LINEAR NO NO POINT
[0073] The first column of Table 1 includes the names of the
various BPM axes, the second column includes concise descriptions
of each axis, the third column includes descriptions of the natures
of motion of machine components with respect to an axis, the fourth
column indicates whether motion with respect to the axis occurs
during the release of the baseball from the BPM, and the fifth
column indicates whether or not motion with respect to the axis
imparts energy to the projected baseball. The X and Z-axes
determine the position of the release point with respect to the
vertical plane of the projection screen. The Y and W axes determine
the initial trajectory of the projected baseball. All four axes X,
Z, Y, and W are static at the point in time that the baseball is
released by the BPM and therefore impart no energy to the baseball.
The reloading axis J is also static at the point in time that the
baseball is projected from the BPM and therefore imparts no energy
to the baseball. Motion about the J axis allows for loading of the
gripper component with the baseball and repositioning of the
electrical cylinder that feeds the baseball into the
counter-rotating flywheels. The I-axis corresponds to motion of a
narrow, vertical portion of the projection screen that contains an
aperture through which the baseball is projected. This aperture is
rapidly moved across point of projection as the baseball is
released, thus creating an instantaneous shutter within the
projection screen. Motion of the projection screen component along
the I-axis thus does not impart energy to the thrown baseball. The
H-axis corresponds to the longitudinal axis of the electric
cylinder along which the baseball is fed into the counter-rotating
flywheels. A portion of the energy of the linear motion of the
baseball along the H-axis is imparted to the projected baseball.
The flywheel housing rotates about the G-axis, thus rotating the
plane that bisects the centers of the two flywheels. In one
embodiment of the BPM, rotation of the flywheel housing about the
G-axis occurs only prior to the release of the baseball, and thus
imparts no energy to the thrown baseball. In an alternate
embodiment of the BPM, the flywheel housing may be rotated with
respect to the G-axis as the baseball is fed into the
counter-rotating flywheels, imparting a rotational spin to the
baseball perpendicular to the G-axis and thus imparting energy to
the projected baseball. This rotational component may be used to
simulate the flicking of a baseball pitcher's wrist when throwing
certain types of baseball pitches. The E and F axes correspond to
the rotational axes of the upper and lower flywheels, respectively.
Momentum of the flywheels imparted to the baseball is the main
source of energy for projecting the baseball from the BPM. The
velocity at which the baseball leaves the BPM is directly
controlled by the rotational speed of the two flywheels. Thus,
motion of the flywheels about the E and F axes imparts energy to
the thrown baseball. In addition, a clockwise or counterclockwise
spin in the plane that passes through the centers of the two
flywheels and bisects the two flywheels can be imparted to the
baseball by rotating the two flywheels at different speeds. Table 1
thus summarizes the motions of major components of the BPM with
respect to the multiple BPM axes as well as their energy
contributions to the projection of the baseball from the BPM.
[0074] Motion with respect to each axis of the BPM is provided by
an electrical servomotor, and, in the case of the I axis, by two
electrical servomotors. In one embodiment of the BPM,
Parker-Hannifin Corp. electrical servomotors are employed. For the
E and F axes, SM-233BR-N motors are used. For the W-axis,
SM-231BBE-NTQN motors are used. For the Y, J, I, and G axes,
SM-N0923KR-NMSB motors are used. Alternate sources for the
electrical servomotors are: Ormec Systems Corp. of Rochester, N.Y.;
Hitachi America, Ltd. of Tarrytown, N.Y.; and Baldor Electric Corp.
of Fort Smith, Ark.
[0075] FIGS. 9 and 10 illustrate the main frame, X-axis frame, and
Z-axis carriage of the BPM. In FIG. 9, the X-axis frame 902 is
positioned towards the left-hand side of the plane of the
projection screen (left and right-handedness is with respect to a
vantage point in front of the BPM, as illustrated in FIGS. 5 and
7), and, in FIG. 10, the X-axis frame 1002 is positioned at the
right-hand side of the projection screen. Similarly, in FIG. 9, the
Z-axis carriage 904 is positioned towards the center of the X-axis
frame 902, while in FIG. 10, the Z-axis carriage 1004 is positioned
towards the top of the X-axis frame 1002. Thus, FIGS. 9 and 10 show
horizontal movement of the X-axis frame across the plane of the
projection screen, and also show vertical movement of the Z-axis
carriage along the X-axis frame. The main frame comprises four
vertical members 906-909, four long horizontal members 910-913, two
short upper horizontal members 914-915, and two short base members
916 and 917. The vertical, long horizontal, and upper short
horizontal members 906-915 are machined lengths of four-inch square
tubular steel welded together as indicated in FIGS. 9 and 10. In a
preferred embodiment, X-axis motion and Z-axis motion are
controlled by belt-driven and lead screw-driven linear motion
systems mounted to the inner sides of the horizontal member 911 and
vertical member 918 of the main frame and X-axis frame,
respectively. Dual Vee Lo Pro Linear Motion Systems from
Bishop-Wisecarver Corp. of Pittsburg, Calif. are employed in both
cases. The X-axis belt driven linear motion system, Lo Pro part
number 3SCSBG3DH100S, is powered by a vertically mounted electrical
servomotor 1006 and the Z-axis lead-screw-driven linear motion
system, Lo Pro part number #SCSLSD, is also powered by a vertically
mounted electrical servomotor 1008. Linear motion systems from
Thomson Saginaw Corp. of Port Washington, N.Y. can also be used to
drive the X and Z axes. The X-axis frame 902 comprises two vertical
members 918-919 and two horizontal members 920 and 922 welded
together as indicated in FIG. 9 to form a rectangular frame. The
vertical and horizontal members 918-922 are machined lengths of
four inch square steel tubing. The X-axis frame also includes an
upper semi-rectangular support 924 and a lower semi-rectangular
support 926. Both semi-rectangular supports comprise three machined
sections of two inch square steel tubing welded together as
indicated in FIG. 9. The upper semi-rectangular support 924 is
welded to the top surface of the X-axis horizontal member 922, and
the lower semi-rectangular support 926 is welded to the bottom
surface of the lower X-axis horizontal member 920. A faceplate 928
is attached to the projection screen side of the Z-axis carriage
904. The faceplate contains an aperture 930 through which a
baseball is projected. The X-axis frame is mounted to the main
frame horizontal members 911 and 913 by pairs of rollers (not
shown) fixed to the projection screen side of the horizontal
members of the X-axis frame 920 and 922 that grip and roll along
linear roller tracks 932 and 934 affixed to the inner surfaces of
the main-frame horizontal members 911 and 913. Similarly, the
Z-axis carriage 904 is mounted to the X-axis frame by pairs of
rollers attached to the projection screen side of two angle bracket
members 1010 and 1012 affixed to vertical members on either side of
the Z-axis carriage 1004 which grip and roll along
vertically-mounted roller tracks 1014 and 1016 affixed to the inner
surface of X-axis frame vertical members 1018 and 1020,
respectively. A more detailed description of the roller and roller
tracks follows.
[0076] FIGS. 11A-C illustrate the roller and roller track mechanism
of the Z-axis carriage. FIG. 11A shows a section view of the main
frame 1102 and Z-axis carriage 1104 looking down, in a vertical
direction, from the top of the BPM. FIG. 11B shows, in more detail,
the circled portion of FIG. 11A, and FIG. 11C shows, in greater
detail, the circled portion of FIG. 11B. In FIG. 11C, two Z-axis
rollers 1106 and 1108, are mounted on shafts 1110 and 1112,
respectively, that are affixed to an angle member 1114 of the
Z-axis carriage. The angle member 1114 is affixed to vertical
member 1116 and horizontal member 1118 of the Z-axis carriage. The
rollers ride along a linear track 1120 affixed to a vertical member
1122 of the X-axis frame. An X-axis frame roller 1124 is attached
via a shaft 1126 to the X-axis frame 1128 and tracks along the
upper edge of a roller track 1130 affixed to the inside edge of an
upper mainframe horizontal member 1132.
[0077] FIG. 12 is an exploded view of the vertical projection
screen of the BPM. The vertical projection screen comprises the
Z-axis carriage faceplate 1202, the right-hand flexible reflective
screen 1204, the left-hand flexible reflective screen 1206, the two
Z-axis mask assemblies, and the I-axis vertical flexible screen
1208. The faceplate 1202 is mounted directly to the front face of
the Z-axis carriage. The right-hand flexible reflective screen 1204
extends and retracts from a vertical take-up/supply reel 1210 and
is affixed to a solid steel rod 1212. Similarly, the left-hand
flexible reflective screen 1206 is extended from a vertical
take-up/supply reel 1214 and is attached to a vertical steel rod
1216. The top end of the right-hand vertical steel rod 1212 is
welded to the projection screen side of the upper semi-rectangular
support member 1218 of the X-axis frame and the lower end of the
vertical steel rod 1212 is welded to the projection screen side of
the lower semi-rectangular support member 1220 of the X-axis frame.
Similarly, the top and bottom ends of the left-hand vertical steel
rod 1216 are welded to the projection screen sides of the upper
semi-rectangular support member 1218 and the lower semi-rectangular
support member 1220, respectively. The I-axis flexible screen
extends between two servo-motor-driven take-up/supply reels 1222
and 1224. The upper servo-motor-driven take-up/supply reel 1222 is
mounted on the upper X-axis frame semi-rectangular support member
1218 and the lower servomotor driven take-up/supply reel 1224 is
mounted to the lower X-axis semi-rectangular support member
1220.
[0078] FIG. 13 is a front view of the I-axis projection screen
mounted to the X-axis frame. The rounded slot 1302 of the I-axis
projection screen 1304 is quickly moved over the aperture 1306 in
the Z-axis carriage faceplate 1308 in order to provide an
instantaneous shutter, or opening, in the projection screen. In
certain embodiments of the BPM, red, yellow, and green lights 1310,
1312, and 1314 respectively, may be positioned above or below the
aperture 1306 in order to warn a baseball batter of the impending
release of the baseball by the BPM. Seven of the eight rollers
1315-1321 by which the X-axis frame is mounted to the horizontal
roller tracks of the main frame are shown in FIG. 13.
[0079] FIGS. 14A-B show a sectional view and an edge-on cross
section of a flywheel used to transfer energy to the baseball in
the BPM. The flywheel is cast from 356-T6 aluminum alloy for
reliable and safe operation up to rotational speeds of 6,000 rpm.
The flywheel is manufactured by Industrial Caster & Wheel
Company, Inc. of San Leandro, Calif. and is commercially available
from Industrial Caster as Part No. 12X3. An alternate source is
Caster Technology Corp. of Kent, Wash., for part number 022-743.
The dimensions of the flywheel are shown in FIG. 14B. The aluminum
casting portion of the flywheel 1402 and 1404 has a radius of 5
inches from center. The outer, cylindrical surface of aluminum
casting 1406 and 1408 is bonded to a continuous circumferential
belt of polyurethane 1410 and 1412 having a compressibility
expressed as a Durometer measurement of 40A to 45A. The outer
surface of the continuous circumferential polyurethane belt 1414
and 1418 slopes upward from both sides towards the center, with a
continuous, semicircular groove formed into the central, outer
circumference of the continuous circumferential polyurethane belt.
The aluminum casting portion of the flywheel comprises a raised
central hub 1420 and 1422 (1424 in plane view of FIG. 14A)
surrounding a central opening 1426 (1428 in the plane of FIG. 14A)
through which the flywheel is mounted to a drive shaft. A thinner,
interior disk 1430 and 1432 (1434 in plane view of FIG. 14A)
extends from the central hub 1420 and 1422 to the outer cylindrical
rim 1436 and 1438 (1440 in plane view of FIG. 14A) of the aluminum
casting portion of the flywheel. The continuous circumferential
polyurethane belt 1410 and 1412 (1442 in plane view of FIG. 14A) is
bonded to the outer cylindrical surface of the aluminum casting
portion of the flywheel.
[0080] FIG. 15 is an exploded view of the flywheel drive assembly.
The flywheel is mounted on an axle 1502. Rotation of the flywheel
is driven by an electrical servomotor 1504. On the servomotor side
of the flywheel, the axle 1502 passes through a keyless tapered
collet coupling 1503, a flange bearing 1506, a mounting plate 1508,
and a motor mount 1510 to a flexible bellows coupling 1512 that
couples the axle to the power shaft of the electrical servomotor.
On the side of the flywheel opposite from the servomotor, the axle
passes through a keyless tapered collet coupling 1514 and a flange
bearing 1516 that is, in turn, mounted to a mounting plate 1518.
Note that the walls of flywheel housing (850 in FIG. 8) pass
between the flange bearings 1506 and 1516 and mounting plates 1508
and 1518 in the flywheel housing assembly. The two keyless tapered
collet couplings 1503 and 1514 are supplied by the Manheim Division
of Fenner Drives Corp. of Manheim, Pa. as Trantorque part number
6202115. The flexible bellows coupling 1512 is available from
Rimtec Corp. of Westmont, Ill. as Gerwah Zero Backlash Coupling
part number DKN45/41.
[0081] FIG. 16 shows an exploded view of a flywheel housing
assembly. The flywheel housing assembly comprises an E-axis
flywheel assembly 1602, an F-axis flywheel assembly 1604, two
linear guides 1606 and 1608, a flywheel housing 1610, a G-axis
electrical servomotor 1612, a cable tray 1614, and a double-ringed
geared turntable bearing 1616. The E-axis assembly 1602 and the
F-axis assembly 1604 are mounted within the flywheel housing 1610
via mounting plates 1618, 1620, 1622, and 1624. The flywheels 1626
and 1628 reside within the flywheel housing enclosure 1610 and the
mounting plates 1618, 1620, 1622, and 1624 are bolted to the
external surface of the flywheel housing, and are adjustable in the
vertical direction to compensate for wear. This adjustment is
accomplished by the use of slotted holes in the mounting plates
1618, 1620, 1622, and 1624 that match drilled and tapped holes in
the flywheel housing 1610, the length of the slots defining the
range of motion available for adjustment. The flywheel axles 1630
and 1632 pass through the servomotor side mounting plates 1618 and
1622 and through square apertures 1634 and 1636 in the flywheel
housing. The lateral guides 1606 and 1608 are horizontally affixed
to the inner surface of the flywheel housing between the two
flywheels to serve as guides for the baseball gripper component
(826 in FIG. 8). The cable tray 1614 is bolted onto two vertical
mounting brackets 1638 and 1640 welded to the flywheel housing
1610. Power and communication cables are wrapped within the well
1642 of the cable tray 1614 to facilitate extension and retraction
of the power and communications cables during rotation of the
flywheel housing about the G-axis. The inner ring of the
double-ringed geared turntable bearing 1616 is bolted to the outer
surface of the cable tray 1614, and the outer geared ring of the
double-ringed geared turntable bearing 1616 is enmeshed with a gear
1644 directly attached to the power shaft of the electrical
servomotor 1612. The fixed gear 1616 thus serves to transduce
rotational motion of the electrical servomotor power shaft into
rotation of the flywheel housing assembly about the G-axis. The
outer geared ring of the double-ringed geared turntable bearing
1616 is also bolted to the W-axis carriage (812 in FIG. 8). The
electrical servomotor 1612 is bolted via a mounting bracket 1644 to
the inner surface of the cable tray 1614, with the power shaft of
the electrical servomotor 1612 extending through an aperture 1646
in the cable tray 1614.
[0082] FIG. 17 shows the fully assembled flywheel housing assembly.
The small gear 1702 affixed to the power shaft of the electrical
servomotor that powers rotation about the G-axis (not shown) is
enmeshed with the outer geared ring of the double-ringed geared
turntable bearing 1704 bolted to the cable tray 1706. The cable
tray 1706 is bolted to the flywheel housing 1708 within which the
flywheel assemblies 1710 and 1712 are mounted. The turntable
bearing is supplied by Kaydon Bearing Corp. of Muskegon, Mich. as
part number MTE-145.
[0083] FIGS. 18, 19, and 20 illustrate the H and J-axes assembly.
The H and J-axes assembly comprises a vertical support 1802, an
angled support 1804, a J-axis base plate 1806, a J-axis electrical
servomotor 1808 and J-axis rotational power transduction gear 1810,
an H-axis electrical cylinder 1812, a stationary guide 1814, and a
baseball gripper assembly 1816. The vertical support member 1802 is
a machined length of one-inch square steel tubing welded to a
horizontal bracket 1818 and to the angled support 1804. The angled
support member 1804 comprises three machined lengths of two-inch
square steel tubing welded together, as indicated in FIG. 18, and
welded to a bracket plate 1820 and to the J-axis base plate 1806.
The J-axis electrical servomotor 1808 is bolted to the bottom side
of the J-axis base plate 1806 with the power shaft of the
electrical servomotor 1808 extending through an aperture in the
J-axis base plate 1806 (not shown) to attach to a power shaft gear
1822. The power shaft gear 1822 enmeshes with the J-axis rotational
power transduction gear 1810 mounted on a shaft extending upward
from the J-axis base plate 1806 and bolted to the H-axis electric
cylinder 1812. The gripper assembly 1816 is affixed to the
extensible arm of the electric cylinder 1812 via a quick disconnect
coupler 1824. The baseball gripper assembly 1816 rides along the
stationary guide 1814 as the baseball gripper assembly 1816 is
translated horizontally by the extensible electric cylinder arm.
The stationary guide 1814 fits into a slot 1826 on the right-hand
side of the baseball gripper assembly 1816.
[0084] FIG. 19 shows the fully assembled H and J-axes assembly in a
retracted position. FIG. 20 shows the fully assembled H and J-axes
assembly with full extension of the extensible arm of the
electrical cylinder. As discussed above, the baseball gripper
assembly 1902 rides along the stationary guide 1904 when the
extensible arm of the electric cylinder is retracted. In FIG. 20,
when the extensible arm of the electric cylinder 2002 is extended,
the baseball gripper assembly 2004 is free to rotate about the
H-axis in order to follow rotation of the flywheel housing assembly
(850 in FIG. 8) about the G-axis. When extended inside the flywheel
housing (1610 in FIG. 16), the baseball gripper assembly 2004
tracks along two fixed guides (1606 and 1608 in FIG. 16).
[0085] FIG. 21 shows an exploded view of the baseball gripper
assembly. The baseball gripper assembly comprises a top plate 2102,
a bottom plate 2104, a male portion of the quick disconnect coupler
2106, right-hand and left-hand gripper fingers 2108 and 2110,
respectively, a gripper spring 2112, a rectangular spacing member
2114, and two triangular spacing members 2116 and 2118,
respectively. The baseball 2120 is pushed between the gripper
fingers 2108 and 2110 which rotate outward in a plane parallel to
the top and bottom plates 2102 and 2104, respectively, via a lever
action, and then close back onto the baseball via tension in the
gripper spring 2112 as the point of contact of the baseball 2120
with the gripper fingers 2108 and 2110 moves past the gripper
finger apexes 2122 (second finger gripper apex obscured by the top
plate 2102). Timing marks 2124 and 2126 are etched into the top
plate 2102 in order to facilitate seam orientation of the baseball
2120.
[0086] FIGS. 22-24 illustrate the W-axis carriage. FIG. 22 shows an
exploded view of the W-axis carriage as seen from a vantage point
near the vertical projection screen looking toward the H and J-axes
assembly. The W-axis carriage comprises a W-axis base plate 2202, a
W-axis vertical trunnion plate 2204, two W-axis rotation pins 2206
and 2208, the H and J-axes assembly 2110, and the flywheel housing
assembly 2112. The W-axis base plate 2202 comprises a flat base
plate with a vertical facing 2214 formed by bending a short section
of the flat base plate upward at a 90.degree. angle from the W-axis
base plate 2202. A W-axis fixed sector gear 2216 is bolted to the
bottom side of the W-axis base plate 2202. The vertical trunnion
plate 2204 is bolted to the vertical facing 2214 of the W-axis base
plate 2202. The flywheel housing 2212 is bolted to the W-axis
vertical trunnion plate 2204 and to the outer geared ring of the
double-ringed geared turntable bearing 2220. The baseball projected
from the flywheel housing 2212 passes through an aperture 2218 in
the vertical trunnion plate 2204. The W-axis carriage is affixed to
the Y-axis carriage via the rotation pins 2206 and 2208 slotted
through apertures 2222 and 2224 near the apex of the trunnions 2226
and 2228 that extend horizontally from the vertical trunnion plate
2204. FIG. 23 shows a partially exploded illustration of the W-axis
carriage seen from an observation point behind the H and J-axes
assembly looking forward towards the vertical projection screen.
FIG. 24 is a horizontal plane view looking down the W-axis. FIG. 25
is also a horizontal plane view looking down the W-axis. In FIG.
25, the W-axis carriage 2502 has been rotated to the right. Thus,
rotation of the W-axis carriage about the W-axis rotation pins 2504
(lower rotation pin not shown) is illustrated in FIGS. 24 and
25.
[0087] FIG. 26 illustrates the Y-axis carriage. The Y-axis carriage
comprises a vertical frame 2602, a horizontal frame 2604, a base
plate 2606, the Y-axis carriage fixed gear extension 2608, the
W-axis carriage 2610, the W-axis electrical servomotor 2612, and
the W-axis rotation pins 2614 and 2615. The Y-axis vertical frame
2602 comprises a rectangular frame welded together from four
machined lengths of two-inch square steel tubing as indicated in
FIG. 26, with a horizontal cross member 2616. The Y-axis carriage
horizontal frame 2604 is welded to horizontal cross frame 2616. The
W-axis trunnion flanges 2618 (lower trunnion flange not shown) fit
over apertures 2620 and 2622 in the Y-axis vertical frame 2602. The
W-axis carriage is rotatably fixed to the Y-axis carriage by the
W-axis rotation pins 2614 and 2615. The W-axis carriage is rotated
by transduction of rotation of the W-axis power shaft gear 2624 via
the W-axis fixed sector gear 2626. The Y-axis carriage is rotatably
joined to the Z-axis carriage via a right-hand trunnion 2628 and a
left-hand trunnion (obscured in FIG. 26). The Y-axis carriage is
rotated about the Y-axis via transfer of rotational motion from the
Y-axis electrical servomotor (not shown in FIG. 26) to the Y-axis
fixed sector gear (also not shown in FIG. 26) bolted to the Y-axis
fixed gear extension 2608. The Y-axis horizontal frame comprises
four machined lengths of two-inch square tubing welded together as
indicated in FIG. 26, to which the Y-axis carriage base plate 2606
is welded. The W-axis electrical servomotor 2612 is bolted to the
Y-axis base plate 2606 with the W-axis electrical servomotor power
shaft extending through an aperture 2630 in the Y-axis base plate
2606. Two angle brackets 2632 and 2634 are bolted to the Y-axis
carriage base plate 2606 to carry electrical limit switches that
prevent excessive angular excursion and over-travel of the W-axis
assembly to exceed its limits. An identical set of two switches are
placed on angle brackets shown in FIG. 27. These switches are
commercially-available as Omron Corp., part number Z15GQ22-B7-K.
These switches, one each for the left and right end of the fixed
sector gear, when activated, stop the respective drive axis motors
for W or Y-axes. If for any reason the machine is commanded to
exceed the software limits set in its operating parameters, the two
limit switches on the Y carriage and the two limit switches on the
W carriage will provide a redundant safe stop with a separate power
supply. The limit switches described are capable of bringing either
carriage assembly to a dead stop within a few hundredths of a
second. This greatly decreases the otherwise low probability of
throwing a wild pitch or hitting a batter. As an alternate to
mechanical limit switches, electrical proximity sensors can be
used, such as part number 5B275 from New Line Corp.
[0088] FIGS. 27 and 28 illustrate rotation of the Y-axis carriage
about the Y-axis. FIG. 27 shows the Y-axis carriage in a horizontal
position, and FIG. 28 illustrates the Y-axis carriage rotated
downward about the Y-axis. The Y-axis fixed sector gear 2702
enmeshes with a gear 2704 directly attached to the power shaft of
the Y-axis electrical servomotor (not shown). Rotation of the
Y-axis electrical servomotor is transduced via the Y-axis fixed
sector gear 2702 to control rotation of the Y-axis carriage about
the Y-axis.
[0089] FIG. 29 illustrates the Z-axis carriage. The Z-axis carriage
comprises the Y-axis carriage 2902, the Z-axis frame 2904, the
Z-axis faceplate 2906, the Y-axis electrical servomotor 2908, and
the Y-axis electrical servomotor mount 2910. The Z-axis frame 2904
comprises twelve machined lengths of two-inch square steel tubing
welded together to form the cage-like structure shown in FIG. 29.
The Z-axis faceplate 2906 is bonded to the Z-axis frame as
indicated in FIG. 29. The Z-axis faceplate 2906 has a reflective
forward surface of the same coloring and reflectivity as the
flexible screens of the vertical projection screens. The faceplate
2906 includes an aperture 2912 through which a baseball is
projected, as well as, in certain embodiments, three lights
2914-2916 that serve as warning lights to alert a batter that a
baseball is about to be projected. The Y-axis electrical servomotor
mount 2910 comprises an angle bracket with an aperture 2918 through
which the power shaft of the Y-axis electrical servomotor 2908
extends. The Y-axis electrical servomotor 2908 is bolted to the
Y-axis electrical servomotor mount 2910 which is, in turn, bolted
to the Z-axis frame 2904 as indicated in FIG. 29. The Y-axis
carriage is rotatably mounted to the Z-axis frame via the Y-axis
rotation pins 2920 and 2922 that extend through apertures in the
Z-axis frame 2924 and 2926, respectively, and the Y-axis carriage
trunnions 2928 (right-handed trunnion obscured in FIG. 29).
[0090] FIGS. 30 and 31 illustrate extension of the baseball into
the counter-rotating flywheels for projection by the BPM. In FIG.
30, a sectional view of the Y-axis carriage is shown. The baseball
3002, gripped by the baseball gripper component 3004, is partially
extended by the H-axis electrical cylinder 3006 towards the
counter-rotating flywheels 3008 and 3010. FIG. 31 shows a cross
section of the W-axis carriage looking down the W-axis from above
the BPM. The baseball 3102 is shown fully extended by the H-axis
electrical cylinder 3104 into the counter-rotating flywheels (lower
flywheel not shown).
[0091] FIGS. 32 and 33 illustrate rotation of the flywheel housing
about the G-axis. In FIG. 32, the flywheel housing 3302 is
vertically positioned with respect to the G-axis. In FIG. 33, the
flywheel housing 3302 has been rotated in a counter-clockwise
direction with respect to the G-axis via rotational motion
generated by the G-axis electrical servomotor 3304.
[0092] FIG. 34 illustrates the electrical and computer control of
the BPM. The BPM is controlled by software programs running on a
personal computer ("PC") 3402. The PC 3402 includes motion control
cards 3404 and 3406 that include logic for translating
software-specified parameters into electrical servomotor rotation.
The motion control cards produce control signals that are amplified
by servo amplifiers 3408 and nine others 3410 that amplify the
signals from the motion controller cards 3404 and 3406 in order to
control the various electrical servomotors 3411-3420. Voltage
signals sent from the motion amplifiers 3408 and nine others 3410
direct the electrical servomotors 3411-3420 to accelerate and
rotate at particular rotational speeds for particular lengths of
time. Software routines running on the PC 3402 translate high-level
specifications, such as the velocity at which the baseball should
be initially projected from the BPM, into rotations for the various
electrical servomotors. A graphical user interface ("GUI") is
displayed by the software programs running on the PC 3402 on a
visual display device 3422. The PC, visual display device, and
servo amplifiers receive electrical power from a power supply
3424.
[0093] In Table 2, below, are shown intermediate values used in the
translation of the velocity of projection of a baseball into E and
F flywheel rotation speeds.
2TABLE 2 SPEED (MPH) SPIN (rpm) E rad/s E rpm E cnt/S F rad/s F rpm
F cnt/S 100 1800 264.0 2523 172253 312 2979 203386 95 1800 248.5
2374 162084 296 2830 193217 90 1800 232.9 2225 151915 281 2681
183047 85 1800 217.3 2076 141745 265 2532 172878 80 1800 201.7 1927
131576 249 2383 162709 75 1800 186.1 1778 121407 234 2234 152539 70
1800 170.5 1629 111237 218 2085 142370 100 1200 280.0 2675 182631
312 2979 203386 95 1200 264.4 2526 172461 296 2830 193217 90 1200
248.8 2377 162292 281 2681 183047 85 1200 233.2 2228 152123 265
2532 172878 80 1200 217.6 2079 141954 239 2383 162709 75 1200 202.0
1930 131784 234 2234 152539 70 1200 186.4 1781 121615 218 2085
142370
[0094] The desired velocity of the baseball is shown in the first
column in miles per hour, the desired rotational spin of the
baseball is shown in the second column in rpm, and rotational
speeds of the E and F flywheels in radians per second, revolutions
per minute, and counts per second are shown in columns 3-8.
[0095] Table 3, shown below, list the fields in a database record
necessary to describe a particular pitch:
3TABLE 3 Field Name Field Type Field Description Pitch varchar
(128) name of path Velocity float velocity of baseball
(translational) major spin float overspin or underspin in #
revolutions minor spin float sidespin in # revolutions target_x
float horizontal coordinate of target target_y float vertical
coordinate of target Image varchar (255) pathname of video file for
pitch Pitcher float name of pitcher in image release time float
time from start of image to release of ball release_x float point
of release on X-axis release-z float point of release on Z-axis
e_spin float counts/seconds for upper flywheel f_spin integer
counts/second for lower flywheel w_angle integer + or - angle from
0.degree. y-angle float + or - angle from 0.degree. g-angle float +
or - angle from 0.degree. h-velocity float velocity of extensible
arm of electrical cylinder
[0096] For each field in the data record, Table 3 lists the name of
the field, in the first column, the data type of data stored in the
field, in the second column, and a concise description of the
contents of the field, in the third column. There are a variety of
different ways in which to store information related to pitches.
Data fields listed in Table 3 represent one of many possible data
schemas that represent one particular approach to storing pitch
data. In the data schema represented by Table 3, various high-level
parameters related to a particular pitch are described, including
the initial velocity at which the baseball is projected from the
BPM, as well as the rotational rate of the baseball in the plane of
the flywheels, or major spin, and the rotation rate imparted to the
baseball by movement of the G-axis, or minor spin. Additional
high-level parameters include coordinates of the target point
within a target area above home plate and coordinates of the
release point of the baseball with respect to the X and Z-axes of
the BPM. Additionally, the name of the pitch and name of the
baseball pitcher whose image is projected on the vertical
projection screen are stored in character-string data fields, along
with the path name of the video file to be projected for the pitch
onto the vertical projection screen. Finally, the data record
described by Table 3 includes angle settings for the W and Y-axes,
which are stored, along with an initial angle setting for the
G-axis and rotation rates for the upper and lower flywheels. In
order to facilitate calculation of rates and initiation times for
motor control, an additional group of auxiliary database tables may
be employed to translate W and Y-axes angles into electrical
servomotor control parameters, to translate the major spin rotation
rate into a differential rotation rate to be added to either the
upper or lower flywheel, depending on whether an over spin or under
spin is desired, and a rotation rate for the G-axis in the case of
an indicated minor spin. Auxiliary database tables can also be used
to store any additional data or parameters required in order to
control the electrical servomotors within the BPM prior to, and
during, the release of the baseball. In one embodiment, detailed
electrical servomotor control parameters are stored for each
different pitch, so that little or no calculation is required in
order to direct the electrical servomotors to execute the pitch. In
an alternate embodiment, the electrical servomotor control
parameters are analytically calculated from the data stored in a
data record, such as the data record described in Table 3. Various
hybrid approaches are also possible.
[0097] FIGS. 35-39 describe the programs that control the BPM.
These programs are executed on the PC (3402 in FIG. 34) to provide
a graphical user interface ("GUI") to the coach or trainer
operating the BPM as well as to direct operation of the various
electrical servomotors within the BPM in a coordinated manner to
execute a particular pitch selected by the coach or trainer.
[0098] FIG. 35 is a flow control diagram illustrating the top level
BPM control program. In step 3502, the BPM is initialized upon
start-up of the system. BPM initialization includes driving the
shutter via the I-axis to a position from which the shutter can be
predictably driven past the Z-axis carriage faceplate as the
baseball is released. Additionally, the electrical servomotors
controlling the other axes may be driven to initial positions, and
the flywheels may be spun up to an initial velocity. In step 3504,
a user interface is displayed on a display monitor to the coach or
trainer that is operating the BPM. This display allows the coach or
trainer to select any of a number of commands in order to operate
the BPM. In step 3506, the BPM control program waits for the coach
or trainer to interact with the GUI displayed in step 3504 in order
to select a next command for execution. If the coach or trainer
indicates that the BPM should be shut down, as detected by the BPM
control program in step 3508, the program shuts down all the
electrical servomotors in step 3510 and returns to step 3512. If,
on the other hand, the coach or trainer selects a pitch command, as
detected by the BPM control program in step 3514, the BPM control
program calls the routine "pitch," in step 3516, to pitch a
baseball. The routine "pitch" will be described in further detail,
below. The coach or trainer may select any of a number of different
informational or maintenance commands, as detected by the BPM
control program in step 3518, which are then executed by the BPM
control program by calling an informational and maintenance command
routine in step 3520. These informational and maintenance commands
are beyond the scope of the current application. They involve data
collection for statistical analysis, testing and calibration
routines, and a variety of additional functions that enhance the
capabilities of the BPM. These informational and maintenance
routines will be the subject of a subsequent patent application.
Finally, if the coach or trainer desires to operate the BPM in a
manual mode, as detected by the BPM control program in step 3522,
the BPM control program calls a routine "manual mode" in step 3524
in order to allow the coach or trainer to manually select all the
various electrical servomotor settings and initiate projection of a
baseball. Additionally, the selected settings in manual mode may be
saved in a data record so that they may be subsequently reproduced.
The manual mode routine will not be described in further
detail.
[0099] FIG. 36 is flow control diagram for the routine "pitch." In
step 3602, the routine "pitch" prompts the coach or trainer to
select a particular pitch. Any number of different GUI's may be
employed for this prompting. For example, the coach or trainer may
be provided a list of well-known pitches, such as the fastball,
slider, curve ball, or other pitches, and then may be provided an
auxiliary menu to select an initial velocity and a point to which
the baseball is to be projected. In step 3604, the routine "pitch"
retrieves an appropriate entry from a pitch database, such as the
data record illustrated in Table 3, above, in order to prepare to
drive the electrical servomotors and display the image of the
pitcher on the vertical projection screen. In step 3606, the
routine "pitch" locates the video image file indicated in the
database record retrieved in step 3604 and queues the video image
file for projection. In step 3608, the routine "pitch" calls a
calculation routine to calculate a time sequence for electrical
servomotor control. In step 3610, the routine "pitch" calls a
projection routine to execute the timed sequence developed in step
3608. In step 3612, the routine "pitch" calls a clean-up routine to
partially re-initialize the BPM for subsequent pitches.
Re-initialization may include returning the shutter via control of
the I-axis to a position from which the shutter is ready to be
subsequently actuated, and may involve retracting the gripper
assembly along the H-axis to allow for subsequent loading of a
baseball. In step 3614, the routine "pitch" prompts the coach or
trainer for a subsequent pitch command. If the coach or trainer
desires the BPM to project another baseball, detected by the
routine "pitch" in step 3616, control returns to step 3602.
Otherwise, the routine "pitch" returns.
[0100] In FIG. 37, the calculation routine called by the routine
"pitch" in step 3608 is illustrated via a control flow diagram.
Steps 3702, 3704, and 3706 comprise a loop in which the calculation
routine calculates timed outputs to the motion controller cards
(3406 and 3408 in FIG. 34) in order to drive each of the electrical
servomotors as indicated by the various fields in the database
record retrieved by the routine "pitch" in step 3604. For example,
if the retrieved database record indicates that the X-axis location
of the release point should be 90 cm from the left-hand side of the
vertical projection screen, then the calculation routine will
calculate a distance between the current position of the release
point and the desired position of the release point along the
X-axis and calculate a motor speed and total time of motor
operation in order to drive the X-axis frame along the X-axis to
the desired release point location. Steps 3708, 3710, and 3712
comprise a loop in which the rotational speeds of the upper and
lower flywheels are determined either directly from the database
record retrieved by the routine "pitch" in step 3604, above, or, in
alternate embodiments, by an analytical or semi-empirical
calculation depending on the indicated initial velocity and major
spin for projection of the baseball. In step 3714, the calculation
routine assembles the determined times for operation of the
electrical servomotors onto a timeline. FIG. 38 illustrates such a
timeline, and will be described below. Finally, the calculations
routine returns in step 3716.
[0101] FIG. 38 illustrates an electrical servomotor operation
timeline. This is a graphical representation of the timeline for
illustrative purposes. In preferred embodiments of the BPM, the
timeline is stored in the memory of the PC (3402 in FIG. 34) as a
list of electrical servomotor control operations stored in an
ascending time sequence. In FIG. 38, the baseball is projected by
the BPM at time zero 3802. Motor control operations that occur
prior to release of the baseball are shown in FIG. 38 at negative
times, to the left of time 0, to be executed prior to the time of
release of the baseball 3802, and motor operations that occur
following the release of the baseball are shown to the right of
time zero 3802. In this example, projection of the image of the
baseball pitcher is started 15 seconds prior to projection of the
baseball 3804 and continues until 2 seconds following the release
of the baseball 3806. The upper and lower flywheels are
incrementally spun up or spun down to a desired velocity at 4
seconds prior to release of the baseball 3608 and 3610. Just after
release of the baseball, the incremental increase or decrease in
the rotation rates of the upper and lower flywheels is ended 3612
and 3614, allowing the upper and lower flywheels to return to an
idle rotation rate or to remain at the same rotation rate in
preparation for a subsequent pitch. Similarly, times for operation
of the other BPM electrical servomotors are shown by additional
horizontal line segments, such as line segment 3616 illustrating
control of the X-axis electrical servomotor to position the X-axis
frame along the X-axis. Note that, when a side spin is indicated
for a pitch, the G-axis electrical servomotor may be first
controlled to a particular initial position 3618 and then,
subsequently, just before release of the baseball, operated to
rotate about the G-axis in the direction of the desired side spin
3620.
[0102] FIG. 39 is a flow control diagram of the projection routine
called by the routine "pitch" in step 3610. In step 3902, the
projection routine transmits inputs to the motion control cards
(3406 and 3408 in FIG. 34) in order to drive the J-axis electrical
servomotor to rotate the H-axis assembly to a position in which a
baseball can be loaded into the gripper component. In step 3904,
the projection routine waits for an indication that the ball has
been loaded. This indication may be input by a coach or trainer to
the GUI, or, in alternate embodiments, the gripper mechanism may
contain electrical/mechanical sensors for detecting the presence of
the baseball within the gripper assembly. In step 3906, the
projection routine controls the J-axis electrical servomotor to
reposition the H-axis assembly coincident with the G-axis in
preparation for projection of the baseball. Note that, in certain
embodiments of the BPM, baseballs may be automatically loaded from
a mechanical magazine. In this case, additional control steps may
be undertaken to control positioning of the magazine and extension
of the gripper assembly via the H-axis to mechanically extract a
baseball from the magazine. Steps 3908-3912 comprise a loop in
which the projection routine selects, in order, each event from the
timeline prepared by the calculation routine in step 3714 of FIG.
37, and executes each selected event. For each selected event, the
projection routine determines, in step 3909 whether the event is a
motor start or incremental motor control command. If so, then in
step 3910, the projection routine sends appropriate control input
to the motion controller card (3406 or 3408 in FIG. 34) to control
the electrical servomotor as indicated in the timeline event.
Otherwise, in step 3911, the projection routine sends appropriate
control input to the motion control card (3406 or 3408 in FIG. 34)
that controls the electrical servomotor indicated in the event to
discontinue operation, remain at the same rotation rate, or return
to an idle rotation rate, in the case of the upper and lower
flywheels. In step 3912, the projection routine determines if there
are any additional events listed in the timeline. If so, as
detected in step 3912, control returns to step 3908. Otherwise, the
projection routine ends.
[0103] The BPM may also be employed as an integral component of a
baseball manufacturing process, and BPM-like devices that represent
alternate embodiments of the present invention may be similarly
employed as integral components for manufacturing of other types of
projectable objects, including tennis balls, footballs, soccer
balls, golf balls, and others. In using the BPM to sort baseballs
into groups of baseballs with similar aerodynamic characteristics,
as described above, it has been found that the aerodynamic
characteristics of commercially produced baseballs vary to quite a
large degree. As discussed above, the differences in aerodynamics
may arise from many different types of differences between
manufactured baseballs, including differences in the overall
weight, distribution of weight, size, seam height, stitching
material, surface texture, perforation size, seam pucker, and other
such characteristics and parameters. Of course, if all such
characteristics and parameters could be controlled to precise
tolerance levels during the manufacturing process, the resulting
manufactured baseballs might vary only slightly in aerodynamic
characteristics. However, it would be economically infeasible to
manufacture baseballs to such close tolerances with respect to
every imaginable parameter.
[0104] Using the BPM, however, many different physical
characteristics and parameters of baseballs can be tested, in a
scientifically controlled manner, to identify those characteristics
and parameters that most significantly contribute to the
aerodynamics of a thrown baseball. For example, a design team can
manufacture a few baseballs to extremely close tolerances, varying
only a single characteristic among the otherwise uniform set of
baseballs, such as seam height, and then projecting the baseballs
using the BPM in a controlled manner to determine the degree to
which the tested characteristic or parameter influences the
baseball's aerodynamics. The design team, through extensive
BPM-based testing and experimentation, can then identify a
reasonably small set of characteristics and parameters to control
to high tolerance during the manufacturing process, and, moreover,
can determine optimal values for the characteristics and parameters
to ensure aerodynamic characteristics within a desirable range. In
a more sophisticated design effect, the effects of covarying two or
more single characteristics and parameters may also be tested to
facilitate selection of the small set of characteristics and
parameters to control during the manufacturing process. The design
team can then devise a baseball-manufacturing process that controls
the identified set of characteristics and parameters to within
tolerance ranges identified by BPM-based testing and
experimentation to provide aerodynamic characteristics within a
desirable range of aerodynamic characteristics.
[0105] As with any manufacturing process, the manufacture of
baseballs and other projectable objects is dynamic, and
significantly varies over time, depending on the availability of
materials, changes in manufacturing standards and rules governing
various sports that employ projectable objects, and the development
and commercial availability of new materials and processes. The
BPM-based testing and experimentation is thus not a single event
that forever dictates one or more particular manufacturing
processes, but is instead an integral component for use, on an
ongoing basis, to continuously analyze the characteristics and
parameters associated with projectable objects in order to derive
economical manufacturing processes that produce aerodynamically
reliable projectable objects.
[0106] Although the present invention has been described in terms
of a particular embodiment, it is not intended that the invention
be limited to this embodiment. Modifications within the spirit of
the invention will be apparent to those skilled in the art. For
example, many types of component configurations and methods of
attaching and mounting components to various assemblies different
from those shown in the figures and described in the above text may
be employed, like, for example, bolting rather than welding. Many
different GUIs may be employed to provide an interface between the
BPM and a user. Sequences of pitches may be selected in advance, so
that the BPM can automatically pitch an entire sequence of pitches
without further user intervention. An almost limitless number of
different software implementations can be employed to control the
electrical servomotors of the BPM in order to pitch baseballs.
Modifications to the BPM may easily provide a tennis-ball-serving
machine, a martial arts weapons throwing simulator, a football
passing machine, and other types of simulators that use video
images to simulate an object projector and modified object
projection components to project a physical object in reproducible
and meaningful ways. The BPM may be scripted to pitch a standard
sequence of pitches for evaluating potential candidate baseball
players in a standard fashion. The PC component of the BPM enables
collection of detailed information, input by a coach or trainer
operating the BPM, with regard to a batter's performance against
the BPM. This detailed information may enable development of player
profiles, training regimes, and other such evaluation and training
methodologies. The BPM may be enhanced to include laser targeting
and calibration systems for rapid, automated calibration of the
BPM. Different types of materials can be used to fashion the
components of the BPM, including different types of circumferential
belts bonded to the flywheels of different compressibilities and
having different surface characteristics.
[0107] The foregoing description, for purposes of explanation, used
specific nomenclature to provide a thorough understanding of the
invention. However, it will be apparent to one skilled in the art
that the specific details are not required in order to practice the
invention. The foregoing descriptions of specific embodiments of
the present invention are presented for purpose of illustration and
description. They are not intended to be exhaustive or to limit the
invention to the precise forms disclosed. Obviously many
modifications and variations are possible in view of the above
teachings. The embodiments are shown and described in order to best
explain the principles of the invention and its practical
applications, to thereby enable others skilled in the art to best
utilize the invention and various embodiments with various
modifications as are suited to the particular use contemplated. It
is intended that the scope of the invention be defined by the
following claims and their equivalents.
* * * * *