US 3598976 A
Description (OCR text may contain errors)
United States Patent  Inventors Jack A. I;
Bradford J. Baldwin, both of Muskegon,
[$4] GOLF GAME COMPUTING SYSTEM "CI-h, 22 armm 521 user 235/151, 273187.273/176 s1 InLCl coa -ma, A63b 67/02 501 FleldotSear-eh 235/151.
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[ References Cled UNITED STATES PATENTS 2,894,753 7/]959 Simjian 273/185 A Primary Examiner- Malcolm A. Morrison Assistant Examiner-Joseph F. Ruggiero Attorney-Hofgren, Wegner, Allen, Stellman 8:. McCord ABSTRACT: A computer system for use in indoor golf games. The system includes data acquisition means for obtaining data relative to the trajectory of a golf ball hit from a tee, a means for receiving the trajectory information and for providing a signal whose magnitude is representative of the initial velocity of the golf ball; a means for decaying the magnitude of the qifiial at a predetermined rate to provide a second signal w ose magnitude is representative of the instantaneous velocity of a golf ball at any corresponding point in the theoretical time of flight of the golf ball; and a display device for utilizing the second signal to provide information relative to the theoretical free flight trajectory of the golf ball to a golfer.
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saw 11 or 11 GOLF GAME COMPUTING SYSTEM CROSS-REFERENCE This application is a division of our copending application Ser. No. 588,922, now 0.8. Pat. No. 3,513,707, filed Oct. 24. l966 and entitled Golf Game (Iomputing System."
BACKGROUND OF THE. INVENTION A number of attempts have been made to provide indoor golf games utilizing computer systems for computing the theoretical free flight trajectory of a golf ball struck by a golfer and which is intercepted before it travels a significant distance. Such games have not enjoyed a large degree of commercial success because heretofore they have not been capable of providing a golfer with all pertinent information relative to his shot. For example, in one commercialized version of an indoor golf game, it is considered that a ball will always follow a predesignated trajectory independently of the angle of elevation or azimuth of the shot and the trajectory is lengthened or shortened only in a manner dependent upon the initial velocity of the shot. In all versions known to be commercialized, none take into account the factor of spin that could produce a hook or a slice. While systems that take into account the factor of spin have been proposed, none have been commercialized.
Furthermore, the systems proposed and/or commercialized neglect a multitude of other factors that influence the trajectory of a golf ball and by doing so are incapable of realistically portraying to a golfer a simulation of the trajectory of the shot that would closely follow the trajectory that would be observed by a golfer if he were to hit the same shot on a golf course.
SUMMARY OF THE INVENTION The principal object of the invention is to provide a new and improved computer system for indoor golf games that maximizes the realism of the results of a shot and displays the results to a golfer.
More specifically, it is an object of the invention to provide such a new and improved computer system utilizing an analog computer.
Another object of the invention is the provision of a computer for an indoor golf game that includes means for determining the initial velocity ofa ball struck from a tee, a means for utilizing the determined initial velocity to determine total instantaneous velocity of the ball at any point during its theoretical flight in a manner that reflects the effect of drag on a ball, and a display device utilizing instantaneous velocity information to display characteristics of the theoretical free flight trajectory to a golfer.
Still another object is the provision of a computer system such as that set forth in the preceding paragraph wherein the means for determining total instantaneous velocity include the decaying means for decaying a characteristic of a signal representing initial velocity at a predetermined rate to provide a second signal having a characteristic which is representative of the instantaneous velocity of a golf ball at any corresponding point in its theoretical flight ofa golf ball.
A further object is the provision in a computing system of a means for effecting a change in the rate of decay of the instantaneous velocity representing a characteristic of the second signal when the same is indicative of a ball velocity such that air flow about a ball in flight would change the laminar flow.
A still further object is the provision in a computing system such as that set forth in the preceding paragraph and having a bounce and/or roll generating circuit of means for effecting an increased decay rate when it is determined that the theoretical free flight of the trajectory of the ball would bring the same into contact with the ground as by bounding or rolling thereon.
A still further object of the invention is the provision of a computing system such as that set forth above wherein the decaying means are comprised of electrical elements and include first and second resistive circuits each arranged to have the second signal applied thereto with the first circuit being continually conductive and the second circuit including means for sensing the magnitude of the second signal and for precluding the second circuit from conducting when the magnitude of the second signal drops below a predetermined level to effect a change in the rate of decay when the computed instantaneous velocity drops below a predetermined value to account for the change in decay rate when the air flow about a golf ball in flight changes to laminar flow.
Further objects and advantages of the invention will become apparent from the following specification taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation of a room housing a computing system made in accordance with the invention;
FIG. 2 is a schematic illustrating the computer-triggering and initial velocity computing system;
FIG. 3 is comprised of FIG. 3A and FIG. 3B, the latter being adapted to be placed to the right of the fonner, and is a schematic illustrating a trigonometry matrix for providing information relative to the initial angle of elevation of the shot;
FIG. 4 is comprised of FIG. 4A and FIG. 4B, the latter being adapted to be placed to the right of the former, and is a schematic of the computer circuitry;
FIG. 5 is comprised of FIG. 5A and FIG. 5B, the latter being adapted to be placed to the right of the former, and is a schematic of a trigonometry matrix for providing information rela tive to the angle of the shot with regard to the azimuth;
FIG. 6 is a planar plan view of a printed circuit used in the spin detector of the instant invention;
FIG. 7 is a side elevation of a form used to support the printed circuit illustrated in FIG. 6 and further illustrates other elements of the spin detector and electrical connections to the computer;
FIG. 8 is a schematic of a spin determining matrix used in conjunction with the spin detector illustrated in FIGS. 6 and 7;
FIG. 9 is a schematic of the circuitry utilized to control a ball spot projector to illustrate the bouncing of a ball;
FIG. I0 is a schematic of automatic reset circuitry that is operated in the event the computer is improperly energized;
FIG. 11 is a side elevation of a ball spot projector;
FIG. I1 is an enlarged front elevation of a portion of the ball spot projector;
FIG. 13 is an enlarged side elevation of a portion of the ball spot projector with parts shown in section;
FIG. I4 is a front elevation of a portion of a ball spot projector with parts shown in section;
FIG. I5 is a bottom view of a tor mechanism;
FIG. I6 is a plan view of a map of a golf hole that may be used in playing a game with an apparatus made according to the invention;
FIG. I7 is a perspective view of a map spot projector system utilizing the map of FIG. 16 at one stage of operation;
FIG. I8 is a perspective view illustrating a stage in the operation of the map spot projecting system subsequent to that illustrated in FIG. 17; and
FIG. 19 is a schematic of a control system for driving the map spot and ball spot projectors with the outputs of the computer.
portion of the ball spot projec- GENERAL DESCRIPTION As noted previously, the principal object of the invention is to provide an indoor game system utilizing a computer that controls output functions which are made visually apparent to a golfer and which are designed to give the visual impression the golfer would have received had he been playing on an actual outdoor golf course. Additionally, the output functions of the computer are used to provide data for various peripheral functions required in an indoor golf game.
More specifically, the computer is adapted to be used in a golf game wherein a tee area is arranged in front of a screen which may receive projected scenes from a projector representative of the views as from different portions of a golf course. The screen is of the penetrable type and behind the screen is placed spin detecting equipment. In front of the screen and between the screen and the tee area, other data acquisition equipment is placed; and the arrangement is such that when a golfer hits a ball from the tee area, the ball will travel a relatively short distance, usually less than 30 feet. After such a distance is traveled, the computer will be provided with all the necessary information required to perform its various functions.
A ball spot projector is arranged to project a small spot of light on the screen, which spot of light simulates a golf ball. When the golf ball is in flight, the spot of light will be moved on the screen by the projector under the influence of the computer to illustrate the trajectory of the ball. Means are also provided so that when the ball spot appears to initially contact the surface of the golf course as seen on the screen, it will be caused to bounce and/or roll. The computer includes means for generating bounce and roll signals which are provided to the ball spot projector to cause the latter to move the projected spot to simulate the bouncing and/or rolling of a golf ball on a fairway or a green, etc.
As mentioned above, spin-detecting equipment is utilized; and accordingly, during the flight of the ball, the computer provides the ball spot projector with information relative to hook or slice such that the projected spot will give the illusion of a hooking or slicing golf ball.
While the effect of drag on a golf ball in flight is not obviously perceptible to a golfer, it does have an effect on the distance that the shot will travel and influences the trajectory of the ball in flight. The computer includes means for diminishing the velocity ofa ball in accordance with the effect of drag as will be seen. As a result, the computed distance a shot would have traveled had it not been intercepted by the spin detecting equipment very accurately represents the actual distance it would have traveled on an outdoor golf course. Furthermore, since the drag information is fed into the ball spot projector along with other information, the trajectory of the ball as evidenced by the projected spot of light on the screen appears to closely simulate that of a ball in flight on an outdoor golf course.
As is well known, when a golf ball is hit properly by most clubs, back spin is imparted onto the ball which tends to provide a lifting force on the golf ball. Of course, the lifting force is somewhat opposed by gravity. The computer further includes means for introducing the effects of lifl and gravity on the ball, and the projected spot of light illustrating the trajectory of the ball is controlled accordingly.
The computer also provides information to a meter which indicates the distance each ball would have traveled had it not encountered the spin detecting equipment. Obviously, on an outdoor golf course such a distance can only be estimated; but in an indoor golf game flexibility is added to the installation by providing the golfer with distance information. Additionally, the computer controls an indicator which informs a golfer that the system is ready to handle the information relative to the next shot thereby enabling the golfer to hit the next shot. The computer also provides an indication to the golfer when the system is not ready to utilize further information such that the golfer is informed that the next shot should not be played.
Because the system contemplated by the instant invention provides for hooking and slicing unlike other systems currently commercially available, it will be appreciated that if a golfer hooks a shot, the next scene projected on the screen should be taken from the left side of the fairway or from the left rough as opposed from the center of the fairway as would be the case if the golfer hit a straight ball. Accordingly, it is necessary to indicate to the golfer which scene should be projected on the screen before the next shot is played and that the scene to be selected cannot be chosen merely as a function as distance. Thus, a map of each hole on a golf course is provided and the map is divided into a plurality of zones, each zone representing a scene. in order to indicate to the golfer which zone his shot would have terminated so as to enable him to select the next scene, information from the computer is fed to a second spot projector not unlike the ball spot projector which is arranged to project a spot of light on the zone on the map of the golf hole in which the shot terminated thereby enabling the golfer to select the scene corresponding to that zone for his next shot.
MATHEMATICS OF THE TRAJECTORY OF A GOLF BALL In order to make the projected ball spot on the screen appear to be a golf ball on an outdoor course, it is necessary to vary it in three distinct ways. Of course, it must be able to move vertically or in a Y direction to illustrate the elevation effect of the shot. It must also be able to be varied horizontally or in an X direction to illustrate the effect of initial direction and that of hook or slice. Finally, it should be varied in size to give the impression of distance in the Z direction. As will be seen, the ball spot projector is controlled in all three ways. However, in order to do such, it will be apparent that the trajectory of a golf ball must be resolved into the three components of azimuth, elevation and length.
lt will also be apparent that at any given instant, these quantitles will vary from their values at another point of time because the instantaneous velocity of the golf ball is continually changing. In this respect, it will be noted that the instantaneous velocity in the Y or vertical direction will be positive and negative at different portions during the trajectory of a shot. Similarly, if a ball is hooked or sliced, the instantaneous velocity of the ball in the azimuth or X direction may also be positive and negative during different portions of the trajectory depending upon its initial direction with regard to the azimuth. Only in the case of the distance in the length or Z direction, will the instantaneous velocity in that direction be positive or zero. Of course, in any event, the magnitude of the instantaneous velocities in any direction will be continually varying.
It has been found that the instantaneous velocity of a golf ball may be generally considered to follow the equation where:
V, is the instantaneous velocity,
V, is the initial velocity, and
K, is the drag coefficient.
It has been found that the drag coefficient K varies with the velocity of the golf ball. For example, when the velocity of the golf ball is less than l00 feet per second, the air flowing about the golf ball is in a laminar state and K, is approximately 0.50. However, at velocities greater that I00 feet per second, the value of K, drops off substantially to about 0.21. While in actuality, the curve representing the value of K, for any given velocity does not represent a step function, it has been found that it is sufficiently linear for the velocities of concern such that the aforementioned values may be used. The manner in which the effect of drag is implemented will be seen hereinafter.
From the foregoing, it will be apparent that the one quantity necessary to determine the instantaneous velocity V, is the initial velocity V,,. The manner in which V, is determined will be described hereinafter.
Since V, may be calculated at any point in the time of trajectory of a golf ball, it will be apparent that it is necessary to resolve V, into its X, Y and Z components, the X direction