Electronic pitching trainer and method for determining the true speed of a sports projectile

• US 8,001,838 B2
• Filed: 08/05/2008
• Issued: 08/23/2011
• Est. Priority Date: 08/07/2007
• Status: Active Grant

• Current Assignee: Jerry B. Roberts
• Original Assignee: Jerry B. Roberts
• Inventors: Roberts, Jerry B.
• Primary Examiner(s): Williams; Hezron E
• Assistant Examiner(s): BELLAMY, TAMIKO D
• Application Number:
  US12/186,130
• Publication Number:
  US 20090298622A1
• Time in Patent Office: 1,113 Days
• Field of Search: 734/88, 473/439, 473454-456, 473/462, 473/476
• US Class Current: 73/488
• CPC Class Codes: A63B 2024/0028 Tracking the path of an object, e.g. a ball inside a soccer pitch
• CPC Class Codes: A63B 2024/0031 at the starting point
• CPC Class Codes: A63B 2069/0006 for pitching
• CPC Class Codes: A63B 2102/02 Tennis
• CPC Class Codes: A63B 2220/30 Speed
• CPC Class Codes: A63B 2220/808 Microphones
• CPC Class Codes: A63B 2220/89 Field sensors, e.g. radar systems
• CPC Class Codes: A63B 24/00 Electric or electronic controls for exercising apparatus of preceding groups; Controlling or monitoring of exercises, sportive games, training or athletic performances
• CPC Class Codes: A63B 24/0021 Tracking a path or terminating locations
• CPC Class Codes: A63B 69/0002 for baseball
• CPC Class Codes: G01P 15/00 Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
• CPC Class Codes: G01S 15/003 Bistatic sonar systems; Multistatic sonar systems
• CPC Class Codes: G01S 15/586 using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
• CPC Class Codes: G01S 15/88 Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00

Abstract

A sensing device obtains range-related data—such as Doppler data or pulse time-of-flight data—from a sports projectile during flight. The time course of the range-related data is employed, in light of predictable characteristics of the projectile trajectory, to determine and output an accurate determination of the projectile speed for one or more points of interest in its flight. Such determination of speed may, for instance, be the speed at the time of projectile release, even though range-related data is gathered later in the flight, when the projectile is traveling neither so fast, nor straight at the sensor. Such sensing device may employ inexpensive short-range acoustic Doppler, and be incorporated into a target device that automatically displays to a pitcher-in-training the speed and ball/strike condition of each pitch.

Claims

1. An automated method for determining an estimate of a speed of a sports projectile at a time of interest, the method comprising:

(A) measuring first data, the first data indicating a first range-rate value corresponding to a first time and comprising the time rate of change in the length of a first path, wherein the first path comprises a first line from an emitting means at a first fixed point to said sports projectile and a second line from said projectile to a sensing means at a second fixed point, wherein the first and second fixed points are fixed in relation to a target means provided for the sports projectile;

(B) measuring second data, the second data indicating a second range-rate value corresponding to a second time and comprising the time rate of change in the length of a second path, wherein the second path comprises a third line from the emitting means at the first fixed point to said sports projectile and a fourth line from said projectile to the sensing means at the second fixed point, wherein the first time differs from the second time; and

(C) estimating the speed of the sports projectile at the time of interest based on the first range-rate value, the first time, the second range-rate value, and the second time.

2. The method of claim 1, wherein (C) comprises estimating the speed of the sports projectile by extrapolating from the first data, the first time, the second data, and the second time, whereby the estimate falls outside the range of the first range-rate and the second range-rate.

3. The method of claim 1, wherein the time of interest comprises a time of release of the sports projectile by a person.

4. The method of claim 1, wherein said sports projectile is proximate to the target means at the first time.

5. The method of claim 1, further comprising:

(D) measuring a relative time of impact of the sports projectile upon the target means; and

wherein (C) comprises estimating the speed of the sports projectile at the time of interest based on the first range-rate value, the first time, the second range-rate value, the second time, and the relative time of impact.

6. The method of claim 1, wherein (C) comprises estimating the speed of the sports projectile along its line-of-intent at the time of interest based on the first range-rate value, the first time, the second range-rate value, the second time, and known characteristics of a restricted set of projectile trajectories.

7. The method of claim 6, wherein estimating comprises extrapolating outside the range of the first range-rate and the second range-rate.

8. The method of claim 6, wherein the time of interest is materially earlier than the first time.

9. The method of claim 6, wherein the path of the sports projectile at the first time makes a material angle with respect to a line connecting the sports projectile to the midpoint between the first fixed point and the second fixed point.

10. The method of claim 6, wherein said sports projectile is proximate to the target means at the first time.

11. An apparatus for determining an estimate of a speed of a sports projectile at a time of interest, the apparatus comprising:

first measuring means for measuring first data, the first data indicating a first range-rate value corresponding to a first time and comprising the time rate of change in the length of a first path, wherein the first path comprises a first line from an emitting means at a first fixed point to said sports projectile and a second line from said projectile to a sensing means at a second fixed point, wherein the first and second fixed points are fixed in relation to a target means provided for the sports projectile;

second measuring means for measuring second data, the second data indicating a second range-rate value corresponding to a second time and comprising the time rate of change in the length of a second path, wherein the second path comprises a third line from the emitting means at the first fixed point to said sports projectile and a fourth line from said projectile to the sensing means at the second fixed point, wherein the first time differs from the second time; and

estimation means for estimating the speed of the sports projectile at the time of interest based on the first range-rate value, the first time, the second range-rate value, and the second time.

12. The apparatus of claim 11, further comprising:

third measuring means for measuring a relative time of impact of the sports projectile upon the target means; and

wherein the estimation means comprises means for estimating the speed of the sports projectile at the time of interest based on the first range-rate value, the first time, the second range-rate value, the second time, and the relative time of impact.

13. An automated method for determining an estimate of a speed of a sports projectile at a time of interest, the method comprising:

(A) measuring, over an interval of time, a plurality of Doppler shifts of energy reflected from the sports projectile;

(B) identifying a plurality of range rates for the sports projectile based on the plurality of Doppler shifts, wherein the plurality of range rates are, as a consequence of cosine error, less than the speed of the sports projectile during the interval of time, wherein the plurality of range rates have a plurality of cosine errors, wherein the plurality of cosine errors have a plurality of magnitudes that vary within the interval of time; and

(C) using the variation among the plurality of magnitudes to extrapolate from the plurality of range rates to obtain a measure of speed of the sports projectile, corrected for cosine error.

14. The method of claim 13, wherein (C) comprises using differences in the plurality of range rate values to extrapolate from the plurality of range rates to obtain a measure of speed of the sports projectile, corrected for cosine error.

15. The method of claim 13, further comprising:

(D) before (A), providing, from a point, a source of wave energy radiating toward the sports projectile.

16. An apparatus for determining an estimate of a speed of a sports projectile at a time of interest, the apparatus comprising:

measurement means for measuring, over an interval of time, a plurality of Doppler shifts of energy reflected from the sports projectile;

range-rate identification means for identifying a plurality of range rates for the sports projectile based on the plurality of Doppler shifts, wherein the plurality of range rates are, as a consequence of cosine error, less than the speed of the sports projectile during the interval of time, wherein the plurality of range rates have a plurality of cosine errors, wherein the plurality of cosine errors have a plurality of magnitudes that vary within the interval of time; and

extrapolation means for using the variation among the plurality of magnitudes to extrapolate from the plurality of range rates to obtain a measure of speed of the sports projectile, corrected for cosine error.

17. The apparatus of claim 16, wherein the extrapolation means comprises means for using differences in the plurality of range rate values to extrapolate from the plurality of range rates to obtain a measure of speed of the sports projectile, corrected for cosine error.

18. The apparatus of claim 16, further comprising:

energy provision means for providing, from a point, a source of wave energy radiating toward the sports projectile.