Method of measuring motion of a golf ball

• US 6,042,483 A
• Filed: 10/29/1997
• Issued: 03/28/2000
• Est. Priority Date: 10/30/1996
• Status: Expired due to Term

• Current Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Original Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Inventors: Katayama, Shu
• Primary Examiner(s): HARRISON, JESSICA
• Application Number:
  US08/960,260
• Time in Patent Office: 881 Days
• Field of Search: 473/150, 473/151, 473/152, 473/153, 473/154, 473/155, 473/156, 473/198, 473/199
• US Class Current: 473/199
• CPC Class Codes: A63B 2024/0031 at the starting point
• CPC Class Codes: A63B 2220/05 Image processing for measuring physical parameters
• CPC Class Codes: A63B 2220/16 Angular positions
• CPC Class Codes: A63B 2220/20 Distances or displacements
• 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 2220/807 Photo cameras
• CPC Class Codes: A63B 2225/74 with powered illuminating means, e.g. lights
• CPC Class Codes: A63B 24/0003 Analysing the course of a movement or motion sequences during an exercise or trainings sequence, e.g. swing for golf or tennis
• CPC Class Codes: A63B 24/0021 Tracking a path or terminating locations
• CPC Class Codes: A63B 43/008 with means for improving visibility, e.g. special markings or colours illuminating or reflecting means A63B43/06
• CPC Class Codes: A63B 69/3658 Means associated with the ball for indicating or measuring, e.g. speed, direction
• CPC Class Codes: A63B 71/06 Indicating or scoring devices for games or players , or for other sports activities

Abstract

There is disclosed a method of measuring the motion of a golf ball. The passing of a club head to hit a ball is detected by a sensor. A detection signal is sent from the sensor to a trigger section of a control unit. In response to the detection signal, shutter signals are sent from the trigger section to first and second cameras at a proper timing, while providing an appropriate time lag between the shutter signals, so as to photograph an image of the hit golf ball through the first and second cameras. The first and second cameras are disposed facing horizontally, apart from each other, and away from the set position of the ball at a predetermined distance. This method enables the motion of the golf ball to be measured even outdoors and through use of a relatively inexpensive apparatus.

Claims

1. A method of measuring the motion of a golf ball, comprising the steps of

detecting by sensor means the passing of a club head to hit a ball set at a predetermined position, wherein the ball has a mark displayed on the outer surface thereof;

sending a detection signal from the sensor means to trigger means of a control unit; and

in response to the detection signal, sending shutter signals from the trigger means to respective first and second CCD cameras having a shutter speed of 1/10,000 to 1/200,000 second at a proper timing, while providing an appropriate time lag between the shutter signals,

photographing an image of the hit golf ball through the first and second CCD cameras, wherein the first and second CCD cameras located facing horizontally, apart from each other, and away from the set position of the ball at a predetermined distance,

comparing the marks of images of the hit ball with each other which are photographed by the first and second CCD cameras and;

determining a motion of at least one certain point of the mark to obtain the motion of the golf ball hit.

2. A method according to claim 1, wherein the speed of the hit ball is calculated based on a distance and a shutter interval between the first and second CCD cameras through use of a calculation section of the control unit.

3. A method according to claim 1, wherein images of the hit ball photographed by the first and second CCD cameras are compared with each other, and a launch angle of the ball with a horizontal line is calculated through use of image-analyzing means of the control unit.

4. A method according to claim 1, wherein the sensor means is set at each of two different positions where the club head to hit the ball passes, and a calculation section of the control unit is caused to calculate the speed of the club head based on a time difference between detection signals issued from the two sensor means.

5. A method according to claim 1, wherein based on the motion of the certain point of the mark, a three-dimensional vector is obtained and through vector analysis based on the three-dimensional vector, the vector of rotational axis and an amount of rotation of the ball are obtained.

6. A method according to claim 5, wherein based on the vector of the rotational axis and the amount of the rotation, an amount of back spin is obtained.

7. A method according to claim 5, wherein based on the vector of the rotational axis and the amount of the rotation, an amount of side spin is obtained.

8. A method according to claim 5, wherein the ball is marked with a black colored arrow having a plurality of angular points and the motion of at least one of the angular points is determined so as to obtain the three-dimensional vector.