Golf ball trajectory and spin sensing system

• US 5,437,457 A
• Filed: 10/04/1993
• Issued: 08/01/1995
• Est. Priority Date: 10/04/1993
• Status: Expired due to Fees

• Current Assignee: Bay Virtual Systems, Inc.
• Original Assignee: Virtual Golf, Inc.
• Inventors: Curchod, Donald B.
• Primary Examiner(s): Millin, Vincent
• Assistant Examiner(s): Owens, Kerry
• Application Number:
  US08/131,489
• Time in Patent Office: 666 Days
• Field of Search: 273/213, 273/176 R, 273/185 R, 273/185 A, 273/185 B, 273/184 R, 273/186.1, 273/183.1, 273/187.1, 273/187.3, 434/252
• US Class Current: 473/199
• CPC Class Codes: A63B 2024/0034 during flight
• CPC Class Codes: A63B 2220/30 Speed
• CPC Class Codes: A63B 2220/35 Spin
• CPC Class Codes: A63B 2220/805 Optical or opto-electronic sensors
• CPC Class Codes: A63B 2220/89 Field sensors, e.g. radar systems
• CPC Class Codes: A63B 24/0021 Tracking a path or terminating locations
• CPC Class Codes: A63B 69/36 for golf
• CPC Class Codes: A63B 69/3658 Means associated with the ball for indicating or measuring, e.g. speed, direction
• CPC Class Codes: G01P 3/487 delivered by rotating magnets
• CPC Class Codes: G01P 3/68 using optical means, i.e. using infrared, visible, or ultraviolet light G01P3/80 takes precedence ; by reflection of waves G01S17/58

Abstract

A golf simulator is provided with an improved trajectory sensing and spin detector. The trajectory sending system includes a first row of light sensors located adjacent to a tee and receiving light from a first light source directly above the tee. Second and third rows of light sensors are positioned away from the tee. The second row receives light from a second source directly overhead. The third row receives light from the first light source where a plane of light is defined between the first light source and the third row of sensors. The time intervals between a golf ball passing from the tee to the first plane of light and to the second plane of light, where the second plane of light is defined by the second light source and the second row of sensors are detected by the first, second, and third rows of light sensors. The angle of elevation of a golf ball is determined as a function of the ratio of the first and second time intervals. A special golf ball has permanent magnets imbedded therein and a first and a second pickup coil and are positioned on opposite sides of the tee to provide output signals corresponding to the spin of the golf ball. Means are provided for combining the output signals of the pickup coils to determine the spin of the golf ball around respective horizontal and vertical axis.

Claims

1. A system for detecting the trajectory of a ball, including:

a first light sensor means;

a first light source means directed toward the first light sensor means;

a second light sensor means;

a second light source means directed toward the second light sensor means;

said first light sensor means and said first light source means arranged to form an angle between said second light sensor means and said second light source means;

means for detecting when the ball interrupts light falling on said first light sensor means;

means for detecting an initial ball position, prior to passing through light generated by said first and second light source means;

means for detecting when the ball interrupts light falling on the second light sensor means;

means for determining the time taken from an initial ball position prior to interruption of the first light sensor means by said ball;

means for determining the time taken from an initial ball position prior to interruption of the second light sensor means by said ball;

means for calculating the position of the ball between the second light source means and the second light sensor means when the ball interrupts the second light sensor means, to determine vertical ball height.

2. The system of claim 1 including means for calculating the position of the ball between the second light source means and the second light sensor means when said ball interrupts the second light sensor means by utilizing the ratio of the time to interrupt the first sensor means or first light means and the time to interrupt the second sensor means or second light means to determine vertical ball height.

3. The system of claim 2 in which said first and second light sensor means consist of multiple sensors.

4. The system of claim 3 including means for identifying which of the multiple sensors the ball interrupts, to determine the horizontal direction of the ball.

5. The system of claim 2 including means for calculating the velocity of the ball from the time intervals.

6. The system of claim 1 including means for computing the vertical height of the ball over the second light sensor means from the ratio of time to interrupt each of said first and second light sensor means from the said initial ball position.

7. The system of claim 1 including means for computing the velocity of the ball from the time to interrupt said first light sensor means from the initial ball position.

8. The system of claim 1 including means for determining the horizontal direction of the ball from the identification of which of the multiple sensors the ball interrupts.

9. A golf ball trajectory sensing system for measuring the flight parameters of a golf ball struck from a tee, comprising:

a first row of light sensors located adjacent to one side of a tee, said tee having a golf ball located thereon, said sensors in said first row of light sensors respectively receiving light from a first light source located directly above the tee;

a second row of light sensors, which are aligned parallel to the first row of light sensors and which are located at a distance away from the tee on the same one side of the golf ball as the first row of light sensors, said sensors in the second row of sensors receiving light from a second light source located directly above the second row of light sensors, said sensors in said second row of light sensors respectively receiving light from said second light source;

a third row of light sensors, which are aligned parallel to the second row of light sensors and which are located at a distance away from the tee on the same one side of the golf ball as the first row of light sensors, said sensors in said third row of light sensors respectively receiving light from said first light source;

means for determining a first time interval which is the time interval between the golf ball passing through light from the first light source as detected by the light sensors in the first row and the golf ball passing through light from the first light source and the light sensors in the third row of light sensors;

means for determining a second time interval which is the time between the golf ball passing through the light from the first light source and the light sensors in the third row of light sensors and the golf ball passing through light from the second source and the light sensors in the second row of light sensors;

means for determining the height of the golf ball as it passes over said light sensors as a function of the ratio of the first and second time intervals.

10. A system for measuring the spin of a golf ball hit from a tee, comprising:

a tee on which is placed a special golf ball with a magnetic field emanating therefrom;

said magnetic field generated by two permanent magnets disposed within a golf ball, said permanent magnets being two elongated structures, aligned in parallel and having their same poles located adjacent to one another to provide a magnetic field which varies as a function of radial direction,

a first inductive pickup positioned on one side of the golf ball for providing a first output signal indicative of the change in magnetic field caused by the golf ball spinning after it is hit from the tee;

a second inductive pickup positioned on the other side of the golf ball and providing a second output signal indicative of the change in magnetic field caused by the golf ball spinning after it is hit from the tee;

first means for combining the first and the second output signals of the first and second inductive pickup for determining the spin of the golf ball around a vertical axis;

second means for combining the first and the second output signals of the first and second inductive pickup for determining the spin of the golf ball around a horizontal axis.

11. The system of claim 10 wherein the first inductive pickup produces voltage V_L and the second inductive pickup produces voltage V_R, the first means for combining and determining spin is arranged to provide a first output signal which is a measure of spin around a vertical axis of

12. A system for detecting the trajectory of a ball, including:

a first light sensor means;

a light source means directed toward the first light sensor means;

the said light source means directed toward a second light sensor means;

said first light sensor means arranged to form an angle between said light source means and said first light sensor means and said light source means and said second light sensor means;

means for detecting when a ball interrupts light falling on said first light sensor means;

means for detecting an initial ball position, prior to crossing the first and second light sensor means;

means for detecting when the ball interrupts the light falling on the second light sensor means;

means for determining the time taken from an initial ball position prior to interruption of the first light sensor means;

means for determining the time taken from an initial ball position prior to interruption of the second light sensor means;

means for calculating the position between the light source means and the second light sensor means when the ball interrupts the second light sensor means, to determine vertical ball height.

13. A method of detecting the trajectory of a ball, comprising the steps of:

directing light from a first light source to a first light sensor;

directing light from a second light source to a second light sensor;

arranging said first light sensor and said first light source to form an angle between said second light sensor and said second light source;

detecting the initial position of a golf ball;

detecting when the ball interrupts the light falling on the second light sensor;

determining the time taken from an initial ball position prior to interruption of the first light sensor;

determining the time taken from an initial ball position prior to interruption of the second light sensor;

calculating the position between the first and second light sources and the first and second sensors at which the ball interrupts the first and second sensors.

14. The method of claim 13 including calculating the position along a first light beam between the second light source and the second light sensor at which said ball interrupts the first light beam by utilizing the ratio of the time for a ball to interrupt a second light beam extending from the first light source to the second light sensor and the time for the ball to interrupt the first light beam.

15. The method of claim 13 including directing light sensors which include multiple sensing devices at either the first or second light sources.

16. The method of claim 15 including identifying which of the multiple sensing devices the ball interrupts.

17. The system of claim 14 including calculating the velocity of the ball from the time intervals between interruptions of the light sensors.

18. The system of claim 13 including computing the vertical height of the ball over the first and second sensors from the ratio of time to interrupt each of said sensors from the initial ball position.

19. The system of claim 14 including determining the horizontal direction of the ball from the particular one of the multiple sensing devices the ball passes over.

20. A system for detecting the trajectory of a golf ball, comprising:

light means for generating a beam of light,

a first row of light sensor means, said first row disposed across an intended path of a golf ball, said first row of light sensor means further disposed such that said beam of light travels along a first path, said first path of light incident upon said first row of light sensor means and such that said path of said golf ball interrupts said first path of said beam of light incident upon said first row of light sensor means,

a second row of light sensor means, said second row disposed separate from said first row of light sensor means, said second row of light sensor means further disposed such that said beam of light travels along a second path, said second path of light incident upon said second row of light sensor means and such that said path of said golf ball interrupts said second path of said beam of light incident upon said second row of light sensor means,

means for detecting an initial golf ball position of said golf ball prior to said ball intersecting said first and second paths of said beam of light,

means for detecting the intersection of said golf ball with said first path of said beam of light and said second path of said beam of light,

means for timing the interval between said intersection of said golf ball with said first path of said beam of light and the intersection of said golf ball with said second path of said beam of light,

means for calculating the trajectory of said golf ball using information derived from said detecting means and said timing means.

21. A system of measuring the spin on a golf ball hit from a tee comprising:

a golf ball having a magnetic field emanating therefrom, said magnetic field generated by two permanent magnets disposed within said golf ball, said permanent magnets being two elongated structures, aligned in parallel and having their same poles located adjacent to one another to provide a magnetic field which varies as a function of radial direction,

at least two inductive sensors disposed in close proximity to said golf ball, said at least two inductive sensors further disposed spaced apart and lying in a plane across an intended path of said ball,

means for measuring the output of said at least two inductive sensors as said ball passes thereby,

means for calculating the spin on said ball using information derived from said measuring means.