Ball motion measuring apparatus

• US 6,579,190 B2
• Filed: 03/15/2001
• Issued: 06/17/2003
• Est. Priority Date: 03/15/2000
• Status: Active Grant

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: Yamamoto, Akio
• Primary Examiner(s): Martin-Wallace, Valencia
• Assistant Examiner(s): White, Carmen D.
• Application Number:
  US09/805,981
• Publication Number:
  US 20010023209A1
• Time in Patent Office: 824 Days
• Field of Search: 473/199, 473/465, 473/407, 473/156, 473/140-141, 736/49
• US Class Current: 473/141
• CPC Class Codes: A63B 2024/0031 at the starting point
• CPC Class Codes: A63B 2024/0034 during flight
• CPC Class Codes: A63B 2102/02 Tennis
• CPC Class Codes: A63B 2102/18 Baseball, rounders or similar games
• CPC Class Codes: A63B 2102/32 Golf
• CPC Class Codes: A63B 2220/35 Spin
• CPC Class Codes: A63B 24/0021 Tracking a path or terminating locations
• CPC Class Codes: A63B 69/3658 Means associated with the ball for indicating or measuring, e.g. speed, direction

Abstract

A ball motion measuring apparatus has a CCD camera having a multi-shutter which can open and close successively; strobes; a swinging speed measuring sensor; and a controlling/computing device connected to the CCD camera, the strobes, and the swinging speed measuring sensor. The swinging speed measuring sensor outputs a trigger signal for opening/closing the shutter to the CCD camera when the swinging speed measuring sensor detects passage of a golf club. Upon receipt of the trigger signal, the multi-shutter opens and closes successively. Synchronously with the opening/closing of the multi-shutter, the strobes emit flashlight sequentially. In this manner, a plurality of images of a golf ball driven by the golf club are photographed in a one-image frame.

Claims

1. A ball motion measuring apparatus comprising:

a CCD camera having a multi-shutter capable of successively opening and closing at a plurality of times at a high speed;

a triggering sensor detecting a movement of a ball-hitting means or that of a ball and outputting a trigger signal to set opening and closing times of said multi-shutter; and

a controlling and computing device connected to said CCD camera and said triggering sensor and having a storing medium for an image frame and an image display means,

wherein owing to a plurality of successive opening and closing of said multi-shutter caused by detection of said triggering sensor, said CCD camera photographs a plurality of ball images on a one-image frame, and said image display means displays said ball images in said one-image frame,

wherein an interval between an opening and closing time and a successive opening and closing time is 1.5 to 3.0 ms, and

wherein based on a plurality of images of a ball photographed in said one-image frame, said controlling and computing device determines a central coordinate of each of images of said ball and computes an actual movement distance of said ball and a flight speed of said ball from an interval between an opening and closing time of said multi-shutter and a successive opening and closing time of said multi-shutter.

2. The ball motion measuring apparatus according to claim 1, wherein strobes having a number equal to or more than the number of opening and closing times of said multi-shutter are connected to said controlling and computing device, and said strobes flash sequentially and synchronously with opening and closing times of said multi-shutter.

3. The ball motion measuring apparatus according to claim 2, wherein said controlling and computing device is connected to a swinging speed measuring sensor, for measuring a swinging speed of said ball-hitting means, having a projector having two projecting parts each emitting a detection ray and a receptor having two light-receiving parts each detecting said detection rays, and said swinging speed measuring sensor is disposed rearward from a ball-hitting position so that said controlling and computing device measures an interval between a time when said ball-hitting means intercepts one of said detection rays and a time when said ball-hitting means intercepts the other detection ray, whereby a swinging speed of said ball-hitting means is computed.

4. The ball motion measuring apparatus according to claim 3, wherein said swinging speed measuring sensor serving as said triggering sensor is horizontally located at a position, 20 mm to 40 mm rearward from said ball-hitting position, orthogonal to an imaginary straight line extending in a predetermined progress direction of said ball and outputting said trigger signal when said ball-hitting means intercepts said detection rays, and

said CCD camera is horizontally located at a position, 100 mm to 300 mm forward from said ball-hitting position, orthogonal to said imaginary straight line to photograph images of said ball immediately after hitting.

5. The ball motion measuring apparatus according to claim 1, wherein based on a plurality of images of a ball photographed in said one-image frame, said controlling and computing device computes an angle of a trajectory passing through central coordinates of images of said ball with respect to a horizontal direction pre-calibrated on said one-image frame to compute a flight angle of said ball with respect to an actual horizontal line.

6. The ball motion measuring apparatus according to claim 3, wherein based on a plurality of images of a ball photographed in said one-image frame, said controlling and computing device computes an angle of a trajectory passing through central coordinates of images of said ball with respect to a horizontal direction pre-calibrated on said one-image frame to compute a flight angle of said ball with respect to an actual horizontal line.

7. The ball motion measuring apparatus according to claim 1, wherein said controlling and computing device compares a diameter of each of a plurality of images of a measuring ball in said one-image frame with a diameter of each of reference images of two or more balls pre-photographed by said CCD camera, which stored in said controlling and computing device adding each data of said balls locating at different positions with respect to an imaginary straight line extending in a predetermined progress direction of said balls to determine a distance from said imaginary straight line and compute a deflection angle of said measuring ball line with respect to said predetermined progress direction.

8. The ball motion measuring apparatus according to claim 3, wherein said controlling and computing device compares a diameter of each of a plurality of images of a measuring ball in said one-image frame with a diameter of each of reference images of two or more balls pre-photographed by said CCD camera, and stored in said controlling and computing device, and said controlling and computing device adds each data of said balls located at different positions with respect to an imaginary straight line extending in a predetermined progress direction of said balls to determine a distance from said imaginary straight line and compute a deflection angle of said measuring ball with respect to said predetermined progress direction.

9. The ball motion measuring apparatus according to claim 5, wherein said controlling and computing device compares a diameter of each of a plurality of images of a measuring ball in said one-image frame with a diameter of each of reference images of two or more balls pre-photographed by said CCD camera, and stored in said controlling and computing device, and said controlling/computing device adds each data of said balls located at different positions with respect to an imaginary straight line extending in a predetermined progress direction of said balls to determine a distance from said imaginary straight line and compute a deflection angle of said measuring ball with respect to said predetermined progress direction.

10. The ball motion measuring apparatus according to claim 1, wherein based on a plurality of images of a ball photographed in said one-image frame, said controlling and computing device determines a central coordinate of each of a plurality of images of a ball photographed in said one-image frame, said controlling and computing device determines a central coordinate of each of a plurality of images of said ball and computes an actual movement distance of a given point on said ball to compute a rotational amount of said ball on a rotational axis passing through a central coordinate of said ball by an interval between an opening and closing time of said multi-shutter and a successive opening and closing time of said multi-shutter.

11. The ball motion measuring apparatus according to claim 3, wherein based on a plurality of images of a ball photographed in said one-image frame, said controlling and computing device determines a central coordinate of each of a plurality of images of said ball and computes an actual movement distance of a given point on said ball to compute a rotational amount of said ball on a rotational axis passing through a central coordinate of said ball by an interval between an opening and closing time of said multi-shutter and a successive time of said multi-shutter.

12. The ball motion measuring apparatus according to claim 5, wherein based on a plurality of images of a ball photographed in said one-image frame, said controlling and computing device determines a central coordinate of each of a plurality of images of said ball and computes an actual movement distance of a given point on said ball to compute a rotational amount of said ball on a rotational axis passing through a central coordinate of said ball by an interval between an opening and closing time of said multi-shutter and a successive opening and closing time of said multi-shutter.

13. The ball motion measuring apparatus according to claim 7, wherein based on a plurality of images of a ball photographed in said one-image frame, said controlling and computing device determines a central coordinate of each of a plurality of images of said ball and computes an actual movement distance of a given point on said ball to compute a rotational amount of said ball on a rotational axis passing through a central coordinate of said ball by an interval between an opening/closing time of said multi-shutter and a successive opening/closing time of said multi-shutter.