Golf ball tracking system
A ball tracking system is disclosed which includes a display, sensors, a launch monitor and a processor that receives data from the sensors and from the launch monitors and outputs a rendering to the display. Specifically, the sensors are positioned to detect a plurality of observed ball flight paths, each in the plurality originating from a different ball strike at a different location. The sensors' field of view is correlated to three-dimensional space. The launch monitor is positioned to detect one of the ball strikes and to measure the launch parameters of that ball strike. The processor performs several processing steps to match the ball strike detected by the launch monitor to the ball flight paths observed by the sensors, and creates a rendering using both the predicted and the observed data.
1. A ball tracking system comprising:
a display;
a sensor positioned to detect a plurality of observed ball flight paths, each in the plurality originating from a different ball strike at a different location; and
wherein the sensor is correlated to three-dimensional space;
a launch monitor positioned to detect one of the ball strikes and to measure the launch parameters of that ball strike;
a processor connected to the display, sensor and launch monitor, wherein the processor is adapted to perform the following steps:
a. receive the launch parameters from the launch monitor;
b. calculate a predicted ball flight path based on the launch parameters;
c. receive image data from the sensor;
d. from the image data, identify an observed ball flight path and a landing event for each of the plurality of observed ball flights paths, further comprising the steps of;
(1) capturing image frames;
(2) performing ball detection within the image frames;
(3) grouping detected balls based on spatial position and time that is characteristic of a ball in motion to form a bail trajectory; and
(4) performing landing event identification based on a discontinuity in the ball trajectory in successive image frames;
e. determine a landing location for each identified landing event;
f. based on the predicted ball flight path determine a matching distance for each of the plurality of landing locations; and
g. select the matching distance that is closest to the predicted ball flight path.
2. The ball tracking system of claim 1 , wherein the processor is adapted to perform the following additional steps:
h. morph the predicted ball flight path with the observed ball flight path and landing location associated with the closest distance to create a new flight path; and
i. communicate to the display a video rendering based on the new flight path.
3. The ball tracking system of claim 2 , wherein step (g) includes:
g(1) compare the closest matching distance to a confidence margin;
g(2) if the closest matching distance is within the confidence margin then continue to steps (h) and (i); and
g(3) if the closest matching distance is not within the confidence margin then skip steps (h) and (i), and communicate to the display a video rendering based on predicted ball flight path.
4. The ball tracking system of claim 2 , wherein:
steps (a), (b), (h) and (i) are performed by a simulator;
steps (c), (d) and (e) are performed by a target processor; and
steps (f) and (g) are performed by a fusion processor.
5. The ball tracking system of claim 2 , wherein:
step (i) is delayed for a time period after the launch monitor detects the ball strike; and
a beginning portion of the rendering is based on the predicted ball flight path, and an ending portion of the rendering is based on the observed ball flight path and landing location associated with the closest distance.
6. The ball tracking system of claim 5 , wherein the beginning portion has a rendering perspective view, and the ending portion has a second rendering perspective view that is different from the first.
7. The ball tracking system of claim 6 , further comprising a rendering transition from the first to the second rendering perspective views, and wherein the transition is discrete.
8. The ball tracking system of claim 6 , further comprising a rendering transition from the first to the second rendering perspective views, and wherein the transition is not discrete.
9. The ball tracking system of claim 1 , wherein:
step ( 3 ) further includes determining the time of the landing event; and
the matching distance in step (f) includes a temporal and a spatial measure of distance.
10. The ball tracking system of claim 9 , wherein:
step (e) further includes determining an observed descent angle and an observed impact speed prior to the landing event; and
the matching distance in step (f) is based on the observed descent angle and an observed impact speed.
11. The ball tracking system of claim 1 , wherein the predicted ball flight path of step (b) includes t p (time of landing) and (x, y, z) p (landing position), and wherein the landing location for each identified landing events of step (e) includes t 0 (time of landing) and (x, y, z) 0 (landing position), and wherein the matching distance is based on the following equation:
D
1
=
t
p
-
t
0
timeout
×
K
t
+
(
x
p
-
x
0
)
2
+
(
y
p
-
y
0
)
2
+
(
z
p
-
z
0
)
2
×
K
p
where timeout is a preset time, and K t , K p are respectively the time and position calibration constants.
12. The ball tracking system of claim 11 , wherein the calibration constants are automatically adjusted based on prior system accuracy.
13. The ball tracking system of claim 11 , wherein the predicted ball flight path of step (b) includes s p (impact speed) and A p (descent angle), and wherein the landing location for each identified landing event of step (e) includes s 0 (impact speed) and A 0 (descent angle), and wherein the matching distance is further based on the following equation:
D 2 =D 1 +|s p −s 0 |×K s +|A P −A 0 |×K a
where K s and K a are speed and angle calibration constants, respectively.
14. The ball tracking system of claim 13 , wherein D 2 is performed on a subset of plurality of observed ball flight paths whose D 1 values are within a refinement margin.
15. The ball tracking system of claim 14 , wherein the refinement margin is based on the closest D 1 value.
16. The ball tracking system of claim 13 , wherein the calibration constants are automatically adjusted based on prior system accuracy.
17. The ball tracking system of claim 1 , the system further comprising
an atmospheric sensor connected to the processor that measures environmental data, wherein the predicted ball flight path is further based on the environmental data measured.
18. The ball tracking system of claim 1 , further comprising a plurality of sensors and a plurality of launch monitors.
19. The ball tracking system of claim 18 , wherein each launch monitor of the plurality of launch monitors is located in a separate driving bay.
20. The ball tracking system of claim 1 , wherein the launch monitor comprises a side-positioned monitor and an overhead launch monitor.
21. The ball tracking system of claim 1 , wherein the display comprises a portable device.
22. The ball tracking system of claim 1 , wherein the processor is adapted to perform the following additional step of assigning a point value to the ball flight path associated with the closest distance, wherein the point value is based on the landing location associated with the closest distance.
23. A method for ball tracking for use with a display and with a sensor positioned to detect a plurality of observed ball flight paths, each in the plurality originating from a different ball strike at a different location, and wherein the sensor is correlated to three-dimensional space, a launch monitor is positioned to detect one of the ball strikes and to measure the launch parameters of that ball strike, the method comprising the steps of:
a. receive the launch parameters from the launch monitor;
b. calculate a predicted ball flight path based on the launch parameters;
c. receive image data from the sensor;
d. from the image data, identify an observed ball flight path and a landing event for each of the plurality of observed ball flights paths, comprising the steps of:
(1) capturing image frames;
(2) performing ball detection within the image frames;
(3) grouping detected balls based on spatial position and time that is characteristic of a ball in motion to form a ball trajectory; and
(4) performing landing event identification based on a discontinuity in the ball trajectory in successive image frames;
e. determine a landing location for each identified landing event;
f. based on the predicted ball flight path, determine a matching distance for each of the plurality of landing locations; and
g. select the matching distance that is closest to the predicted ball flight path.
24. The method of claim 23 , further comprising the steps of:
h. morph the predicted ball flight path with the observed ball flight path and the landing location associated with the closest distance to create a new flight path; and
i. communicate to the display a video rendering based on the new flight path.
25. The method of claim 23 , further comprising the step of assigning a point value to the ball flight path associated with the closest distance, wherein the point value is based on the landing location associated with the closest distance.
26. A data processing apparatus, comprising a processor configured to perform the method of claim 23 .
27. The data processing apparatus of claim 26 , wherein the processor is further configured to perform the followings steps:
morph the predicted ball flight path with the observed ball flight path and the landing location associated with the closest distance to create a new flight path; and
communicate to the display a video rendering based on the new flight path.