Opto-electric golf club swing sensing system and method

• US 5,472,205 A
• Filed: 06/20/1994
• Issued: 12/05/1995
• Est. Priority Date: 06/20/1994
• Status: Expired due to Fees

• Current Assignee: Guillemot Corporation A French Societe Anonyme
• Original Assignee: ThrustMaster, Inc. (Guillemot Corporation SA)
• Inventors: Bouton, Frank M.
• Primary Examiner(s): HARRISON, JESSICA
• Application Number:
  US08/263,615
• Time in Patent Office: 533 Days
• Field of Search: 273/183.1, 273/186.1, 273/186.3, 273/185 R, 273/185 A, 273/185 B, 273/187.1, 273/195 R, 273/148 B, 434/252
• US Class Current: 473/222
• CPC Class Codes: A63B 2220/805 Optical or opto-electronic sensors
• CPC Class Codes: A63B 69/3614 using electro-magnetic, magnetic or ultrasonic radiation emitted, reflected or interrupted by the golf club
• CPC Class Codes: A63F 13/213 comprising photodetecting means, e.g. cameras, photodiodes or infrared cells A63F13/219, A63F13/655 take precedence
• CPC Class Codes: A63F 13/245 specially adapted to a particular type of game, e.g. steering wheels
• CPC Class Codes: A63F 13/428 involving motion or position input signals, e.g. signals representing the rotation of an input controller or a player's arm motions sensed by accelerometers or gyroscopes
• CPC Class Codes: A63F 13/573 using trajectories of game objects, e.g. of a golf ball according to the point of impact
• CPC Class Codes: A63F 13/812 Ball games, e.g. soccer or baseball
• CPC Class Codes: A63F 2300/1062 being specially adapted to a type of game, e.g. steering wheel
• CPC Class Codes: A63F 2300/1087 comprising photodetecting means, e.g. a camera
• CPC Class Codes: A63F 2300/646 for calculating the trajectory of an object
• CPC Class Codes: A63F 2300/6684 by dynamically adapting its position to keep a game object in its viewing frustrum, e.g. for tracking a character or a ball
• CPC Class Codes: A63F 2300/8011 Ball

Abstract

A video golf system responsive to a user swinging a golf club is described. The system includes a video golf game operating on a personal computer having a monitor, a microprocessor, and a serial port. A golf club swing sensing system is coupled to the personal computer through the serial port of the personal computer. The sensing system is mounted on a pad and includes a linear array of photodetectors for detecting a club head offset angle relative to a desired club head axis by sensing reflected light off the underside of the club head. An analog comparator coupled to each photodetector converts the offset to a digital format. A microcontroller samples the digital offset data and processes the data into a form of information required by the personal computer. An input cable coupled between an output of the microcontroller and the serial port transmits the information to the personal computer. The golf game is responsive to the information to determine a corresponding ball path used as an input to the video game.

Claims

1. A golf club swing sensing system for sensing a golf club head moving along a club path and supplying the sensed information to a personal computer having a microprocessor, an input port, a monitor and a golf video game operable on the microprocessor, the sensing system comprising:

a horizontal pad having a club head axis defined thereon;

a light source including a first plurality of light emitting diodes for illuminating the underside of the club head disposed in the pad;

means disposed in the pad transversely of the club head axis for sensing the offset of the club head relative to the club head axis responsive to light from the light source reflected off an underside of the club head;

means coupled to the sensing means for converting the offset to a digital format, said sensing means including a first linear array of photodetectors disposed transversely to the club head axis, one of the first plurality of light emitting diodes being interposed between adjacent photodetectors of the first linear array, each photodetector producing an output signal proportional to the amount of detected light reflected off the underside of the club head;

means coupled between the converting means and the personal computer for transmitting the digital format offset to the microprocessor for input to the golf video game; and

means for detecting club head direction including

a second plurality of light emitting diodes for illuminating the underside of the club head, and

a second sensing means including a second linear array of photodetectors disposed in parallel with the first linear array of photodetectors, one of the second plurality of light emitting diodes being adjacent each photodetector of the first linear array, each photodetector producing an output signal proportional to the amount of detected light reflected off the underside of the club head.

2. A golf club swing sensing system according to claim 1 further comprising means for detecting the height of the club head at the club head axis responsive to the light from the light source reflected off the underside of the club head.

3. A golf club swing sensing system according to claim 2 wherein the means for detecting the height of the club head at the club head axis comprises:

a resistor divider network having an input for receiving a reference voltage signal and a plurality of outputs for providing a respective fractional reference voltage signal; and

a plurality of comparators each having a first input coupled to the sensing means for receiving a voltage signal proportional to the light detected by the sensing means, a second input connected to a respective one of the resistor divider network outputs for receiving a respective reference voltage signal, and an output for producing a respective output height signal.

4. A golf club swing sensing system for sensing a golf club head moving along a club path and supplying the sensed information to a personal computer having a microprocessor, an input port, a monitor and a golf video game operable on the microprocessor, the sensing system comprising:

a horizontal pad having a club head axis defined thereon;

a light source including a first plurality of light emitting diodes for illuminating the underside of the club head disposed in the pad wherein first plurality of light emitting diodes include a plurality of pairs of light emitting diodes, each pair being associated with a corresponding photodetector, each one of the pair being disposed on a respective side of the corresponding photodetector;

means disposed in the pad transversely of the club head axis for sensing the offset of the club head relative to the club head axis responsive to light from the light source reflected off an underside of the club head;

means coupled to the sensing means for converting the offset to a digital format, said sensing means including a first linear array of photodetectors disposed transversely to the club head axis, one of the first plurality of light emitting diodes being interposed between adjacent photodetectors of the first linear array, each photodetector producing an output signal proportional to the amount of detected light reflected off the underside of the club head;

means coupled between the converting means and the personal computer for transmitting the digital format offset to the microprocessor for input to the golf video game;

means for driving one of the light emitting diodes of each pair with a clock signal; and

means for driving the other one of the light emitting diodes of each pair with a complementary clock signal, wherein the intensity of the combined light emitted by each pair exceeds the maximum intensity of the individual light emitting diodes.

5. A golf club swing sensing system according to claim 4 wherein the converting means comprises a comparator having a first input coupled to a respective one of the photodetectors for receiving a voltage signal proportional to the light detected by the respective photodetector, a second input for receiving a reference voltage, and an output coupled to the transmitting means.

6. A golf club swing sensing system according to claim 5 wherein the transmitting means comprises:

a microcontroller having a plurality of inputs coupled to the converting means, and an output; and

a cable connected to the microcontroller output and connectable to the input port of the computer.

7. A golf club swing sensing system according to claim 5 wherein the clock signal and the complementary clock signal each have a frequency approximately equal to the maximum bandwidth of the individual light emitting diodes.

8. A golf club swing sensing system for sensing a golf club head moving along a club path and supplying the sensed information to a personal computer having a microprocessor, an input port, a monitor and a golf video game operable on the microprocessor, the sensing system comprising:

a horizontal pad having a club head axis defined thereon;

a light source disposed in the pad;

means disposed in the pad transversely of the club head axis for sensing the offset of the club head relative to the club head axis responsive to light from the light source reflected off an underside of the club head;

means coupled to the sensing means for converting the offset to a digital format; and

means coupled between the converting means and the personal computer for transmitting the digital format offset to the microprocessor for input to the golf video game, wherein said transmitting means includes;

a cable having first and second sets of conductors coupled to the converting means,

a first game board connector coupled to the first set of conductors, and

a second game board connector coupled to the second set of conductors, the first and second connectors being connectable to first and second compatible connectors, respectively, on a dual port game card received in the personal computer.

9. A golf club swing sensing system for sensing a golf club head moving along a club path and supplying the sensed information to a personal computer having a microprocessor, an input port, a monitor and a golf video game operable on the microprocessor, the sensing system comprising:

a horizontal pad having a club head axis defined thereon;

a light source disposed in the pad;

means disposed in the pad transversely of the club head axis for sensing the offset of the club head relative to the club head axis responsive to light from the light source reflected off an underside of the club head;

means coupled to the sensing means for converting the offset to a digital format;

means coupled between the converting means and the personal computer for transmitting the digital format offset to the microprocessor for input to the golf video game;

means for detecting the height of the club head at the club head axis responsive to the light from the light source reflected off the underside of the club head, said height detector means including;

a resistor divider network having an input for receiving a reference voltage signal and a plurality of outputs for providing a respective fractional reference voltage signal, and

a plurality of comparators each having a first input coupled to the sensing means for receiving a voltage signal proportional to the light detected by the sensing means, a second input connected to a respective one of the resistor divider network outputs for receiving a respective reference voltage signal, and an output for producing a respective output height signal; and

means for calibrating the height detector means including;

a capacitor,

a first resistor coupled to the capacitor for charging the capacitor to a desired voltage level,

a second resistor coupled to the capacitor for discharging the capacitor,

an amplifier having an input coupled to the capacitor for receiving the capacitor voltage level, and an output, and

means coupled between the amplifier output and the light source for producing a bias voltage, the light source being responsive to the bias voltage to adjust the light produced thereby in accordance with changes in the bias voltage.

10. A golf club swing sensing system for sensing a golf club head moving along a club path and supplying the sensed information to a personal computer having a microprocessor, an input port, a monitor and a golf video game operable on the microprocessor, the sensing system comprising:

means for detecting the velocity of the club head;

means for determining an optimal club head sampling rate responsive to the detected club head velocity;

means for detecting the club head position at the optimal club head sampling rate;

means for determining swing characteristics from the detected club head position; and

means for transmitting the swing characteristics to the personal computer, wherein the video game is responsive to the swing characteristics to determine a ball path on the monitor corresponding to the swing characteristics.

11. A golf club swing sensing system according to claim 10 wherein the means for determining an optimal club head sampling rate responsive to the velocity of the club face includes a microcontroller having a predetermined number of memory locations.

12. A golf club swing sensing system according to claim 11 wherein the means for determining an optimal club head sampling rate responsive to the velocity of the club face includes means for varying optimal club head sampling rate from a target club head sampling rate in response to deviations of the detected club head velocity from the target club head velocity.

13. A golf club swing sensing system according to claim 10 wherein the means for detecting the velocity of the club head includes:

a first photodetector positioned along the club path for detecting the light from the light source reflected off the underside of the club head, the first photodetector having an output for producing a first output signal proportional to the amount of light detected by the first photodetector;

a second photodetector disposed a predetermined distance from the first photodetector along the club path for detecting the light from the light source reflected off the underside of the club head, the second photodetector having an output producing a second output signal proportional to the amount of light detected by the second photodetector;

first comparator coupled to the first photodetector for converting the first output signal to a first digital signal;

second comparator coupled to the second photodetector for converting the second output signal to a second digital signal;

means for timing transitions between the first digital signal and the second digital signal; and

means for converting the time between transitions to a velocity.

14. A method of controlling a golf video game operating on a personal computer having a monitor which operates responsive to a golf club, the golf club head attached at an end of a shaft and having a club face for impacting a golf ball, the method comprising:

detecting the height of the club head at an impact point during address;

detecting the height of the club head at the impact point as the club head moves along a club head path;

comparing the detected club head height detected as the club head moves along a club head path with the detected club head height detected during address;

classifying the swing responsive to the comparison; and

transmitting the swing classification to the personal computer wherein the golf video game is responsive thereto;

wherein the step of detecting the height of the club head at an impact point during address includes

generating a light beam that is directed at an underside of the club head,

detecting the amount of generated light reflected off the underside of the club head,

reducing the intensity of the light beam until no amount of generated light reflected off the underside of the club head can be detected, and

increasing the intensity of the light beam a predetermined amount to establish a threshold light intensity.

15. A method of controlling a golf video game according to claim 14 wherein the step of detecting the height of the club head at the impact point as the club head moves along a club head path includes detecting the amount of generated light reflected off the underside of the club head.

16. A method of controlling a golf video game according to claim 15 wherein the step of comparing the detected club head height detected as the club head moves along a club head path with the detected club head height detected during address includes comparing the amount of generated light reflected off the underside of the club head detected as the club head moves along the club head path with the threshold light intensity.

17. A method of controlling a golf video game according to claim 14 further comprising detecting a plurality of offset angles of the club face relative to a vector as the club head moves past the impact point as the club head moves along a club head path.

18. A method of controlling a golf video game according to claim 17 further comprising:

classifying each detected offset angle as a hook, a slice, or a straight offset angle;

accumulating the hook offset angles;

accumulating the slice offset angles; and

characterizing the swing as a hook swing where the accumulated hook offset angles exceeds a predetermined hook amount, and

characterizing the swing as a slice swing where the accumulated slice offset angles exceeds a predetermined slice amount.

19. A method of controlling a golf video game according to claim 18 wherein the step of detecting the offset angle includes detecting the club face at discrete sample points, and wherein the step of classifying each detected offset angle as a hook, a slice, or a straight offset angle includes:

comparing a first and a second adjacent samples; and

determining a hook offset where the first sample is greater than the second sample, a slice offset where the first sample is less than the second sample, and a straight offset where the first sample is equal to the second sample.

20. A method of controlling a golf video game according to claim 19 further including repeating the comparing and determining steps for a plurality of adjacent pairs in the discrete points.

21. A method of controlling a golf video game according to claim 14 further comprising the step of detecting the velocity, the velocity detecting step comprising:

detecting the golf club head passing a starting point;

detecting the golf club head passing a stopping point, the stopping point being a predetermined distance along the club path from the starting point;

measuring the elapsed time between the club head passing the starting and stopping points; and

dividing the predetermined distance by the elapsed time to calculate the club head velocity, the video game being responsive to the club head speed.

22. A method of controlling a golf video game operating on a personal computer having a monitor which operates responsive to a golf club having a club head attached at an end of a shaft, the method comprising:

detecting the velocity of the club head;

determining an optimal club head sampling rate responsive to the detected club head velocity;

detecting the club head position at the optimal club head sampling rate;

determining swing characteristics from the detected club head position; and

communicating the swing characteristics to the personal computer, wherein the video game is responsive to the swing characteristics to determine a ball path on the monitor corresponding to the swing characteristics.

23. A method of controlling a golf video game according to claim 22 wherein the step of determining an optimal club head sampling rate responsive to the velocity of the club face includes:

choosing a target number of samples;

choosing a target club head velocity;

selecting a target club head sampling rate in accordance with the target club head velocity and the target number of samples; and

varying optimal club head sampling rate from the target club head sampling rate in response to deviations of the detected club head velocity from the target club head velocity.

24. A method of controlling a golf video game according to claim 23 wherein the step of varying optimal club head sampling rate from the target club head sampling rate in response to deviations of the detected club head velocity from the target club head velocity includes decreasing the sampling rate in response to a decrease in the detected club velocity under the target club head velocity.

25. A method of controlling a golf video game according to claim 23 wherein the step of varying optimal club head sampling rate from the target club head sampling rate in response to deviations of the detected club head velocity from the target club head velocity includes increasing the sampling rate in response to an increase in the detected club velocity over the target club head velocity.

26. A method of controlling a golf video game according to claim 22 wherein the step or choosing a target number of samples includes allocating a predetermined number of memory locations for storing samples of the detected club head position.

27. A method of controlling a golf video game according to claim 26 wherein the step of choosing a target number of samples includes allocating 64 memory locations for storing samples of the detected club head position.

28. A method of controlling a golf video game according to claim 22 wherein the step of choosing a target club head velocity includes choosing a target head velocity equal to 100 miles per hour.

29. A method of controlling a golf video game operating on a personal computer having a monitor, the video game operable responsive to a golf club having a golf club head attached at an end of a shaft and having a club face for impacting a golf ball, the method comprising:

detecting a club head position including at least one angle of the club face; and

transmitting the detected club head position information to the personal computer, wherein the video game is responsive to the detected club head information to determine a corresponding ball path;

wherein the step of detecting the club head position includes

forming a matrix of club head samples,

logically ORing successive samples of the matrix to form a resultant matrix, summing the columns of the resultant matrix,

performing a regression analysis on the sums of the resultant matrix to produce a slope, and

determining the angle of the club face from the slope.

30. A method of controlling a golf video game according to claim 29 wherein the step of determining the angle of the club face from the slope includes taking the arctangent of the slope to produce the club face angle.

31. A method of controlling a golf video game according to claim 29 wherein the step of determining the angle of the club face from the slope includes multiplying the slope by approximately two to produce the club face angle.

32. A method of controlling a golf video game operating on a personal computer having a monitor, the video game operable responsive to a golf club having a golf club head attached at an end of a shaft and having a club face for impacting a golf ball, the method comprising:

detecting a club head position including at least one angle of the club face;

transmitting the detected club head position information to the personal computer, wherein the video game is responsive to the detected club head information to determine a corresponding ball path;

detecting the follow-through of the club head by sensing reflected light off an underside of the club head;

detecting the height of the club head; and

transmitting the club head height information and the club head follow-though information to the personal computer, wherein the video game is responsive to the detected club head information to determine a corresponding ball path.

33. A method of controlling a golf video game operating on a personal computer having a monitor, the video game operable responsive to a golf club having a golf club head attached at an end of a shaft and having a club face for impacting a golf ball, the method comprising:

detecting a club head position including at least one angle of the club face including sensing light reflected from an underside of the club head; and

transmitting the detected club head position information to the personal computer, wherein the video game is responsive to the detected club head information to determine a corresponding ball path.

34. A method of controlling a golf video game according to claim 33 wherein the step of detecting the club head position includes determining a club head angle about a horizontal club swing path.

35. A method of controlling a golf video game according to claim 33 wherein the step of detecting the club head position includes determining a club face pitch relative to a vertical plane normal to a horizontal club swing path.

36. A method according to claim 33 in which detecting club head position includes sensing light transmitted horizontally across a club swing path.