JPH04347181A - Golf practice and simulation method - Google Patents

Abstract

PURPOSE: To observe a flying track of a golf ball to a landing point by analyzing and calculating the flying track of the golf ball in a three-dimensional space by photoelectric measurement to reproduce and display an image of the flying track. CONSTITUTION: A photoelectric apparatus 10 comprises a trigger unit 11, an overhead photographing unit 12, and a ground surface photographing unit 13 and measures an actual flying track of a golf ball struck. A control/display device 14 comprises a frame/grapper memory unit 15, a processing/control unit 16, a window memory unit 17 and a display monitoring unit 18 to reproduce and display the flying track of the golf ball measured on a color display monitor. An overhead lighting unit 19 is provided to enhance an photoelectric contrast for measuring the action at an initial flying state of the ball. A wind sensor unit 20 is provided to put a wind force element into a calculation algorithm for the flying track of the ball.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a golf batting training and simulation method, and more specifically, the present invention relates to a method for golf batting training and simulation, and more specifically, a method for analyzing and calculating the flight trajectory of a golf ball in a three-dimensional space at a golf batting range (practice range) etc. by electro-optical measurement. The present invention relates to a method for instantly reproducing and displaying an image of the flight trajectory of the golf ball.

0002

BACKGROUND OF THE INVENTION In recent years, golf hitting ranges (practice ranges) have been designed to have two types of tees, high and low, allowing players to practice with both wood and iron. Additionally, the protective net that surrounds the practice area is designed to be large enough to allow players to observe the long flight trajectory of the balls they hit. Therefore, the player can practice repeatedly by taking the visual evaluation obtained through the observation into consideration in the next ball hitting method. For this reason, night training requires sufficient lighting to observe the ball over long distances. In general, players analyze their own batting results,
The current batting result is simply evaluated subjectively without any means of comparison with the ideal batting result or with one's previous batting results.

[0003] As a means to avoid this and obtain an objective evaluation, there is a golf simulation method. Existing golf simulation methods generally fall into two categories. In the first system, such as Sony's "Birdie Rush System," the golf ball is flexibly coupled to a device with an electromechanical measuring mechanism that allows the system to determine the initial impact on the ball, the initial exit angle,
and measuring the spin variables of the blow. The ball flight trajectory simulated by this measurement is displayed on a video screen along with images of various golf courses. In addition, a second method, for example, "Par T golf system"
In this case, an electro-optical device is installed to measure the initial velocity vector of a golf ball actually hit toward a large synthetic screen several meters away from the tee. The spin variables associated with slices and hooks are roughly calculated by the angle of return of the ball from the screen. The simulated flight trajectory is then optically projected in the same way as being superimposed on the golf course image projected onto the same screen.

0004

[Problems to be Solved by the Invention] However, in any case, the conventional simulation methods described above do not allow the player to completely observe the actual flight trajectory of the ball. The problem was that there was no way to evaluate it. In addition, none of these methods takes into account the natural requirement of wind, which alters or limits the flight of the ball, and thus prevents the player from competing with such natural requirements, thus making the actual There was a problem in that the batting practice left some dissatisfaction.

[0005] Even in the case of an open-air batting practice range where you can observe the actual flight trajectory of the ball, there are cases where it is difficult to see the ball in the distance due to insufficient lighting at night, or where it is difficult to identify the ball due to the crowded background. In some cases, such as when the size of the protective net installed is insufficient and the ball's flight is obstructed midway through, there is a problem in that the ball cannot be observed until the end. Particularly in this case, there is a problem in that slices and hooks that normally occur in the latter half of the flight trajectory cannot be sufficiently observed, and therefore cannot be corrected.

An object of the present invention is to analyze and calculate the flight trajectory of a golf ball in three-dimensional space by electro-optical measurement, and immediately reproduce and display an image of the flight trajectory of the golf ball. The object of the present invention is to realize a golf batting training and simulation method in which the flight trajectory of a ball can be observed up to its final destination.

[0007]

[Means for solving the problem] The invention according to claim 1 includes:
initial velocity vector determining means for electro-optically observing a golf ball flying after being hit from a tee and determining an initial velocity vector of the golf ball flying after being hit from the observation result and the tee position; The flight trajectory of the golf ball is determined by electro-optically tracking the trajectory of the golf ball flying in an observable state in an observation direction determined based on the initial velocity vector of the golf ball determined by the initial velocity vector determining means. a first variable calculation means for calculating a variable to be determined; and a flight trajectory of the golf ball determined based on the variables calculated by the first variable calculation means, which is stored in a memory. The present invention is characterized by comprising a video reproducing means for immediately reproducing an image of the flight trajectory of the golf ball on a display. The initial velocity vector determining means is, for example, a short-time exposure TV.
It consists of an overhead imaging unit such as a camera, and a processing/control unit such as a microprocessor that is synchronized with the overhead imaging unit. Further, the first variable calculation means is composed of, for example, a ground imaging unit formed of a high-resolution CCD-TV camera or the like. Furthermore, the video reproduction means includes, for example, a frame grabber memory unit, a display monitor unit, and the like.

The invention as set forth in claim 2 provides, in addition to the means of the invention as set forth in claim 1, a range of the flight trajectory of the golf ball that flies after being hit, a wind element, and a horizontal spin (slice/slice).
It further includes a second variable calculating means for calculating a flight trajectory variable of the golf ball, which is composed of a hook element, a lift element, and a deterrent force element, and uses the calculated variable to calculate the flight trajectory of the hit golf ball. The present invention is characterized by comprising an image superimposing means for simulating the flight trajectory of the golf ball and superimposing the image of the simulated flight trajectory of the golf ball on an actual or drawn image of the golf course. The second variable calculating means includes, for example, a microprocessor, and the image superimposing means includes, for example, a golf course database unit such as an optical desk, a CRT (CRT), etc.
athode-ray tube display;
It consists of a display monitor unit such as a cathode ray tube display (cathode ray tube display device), etc.

According to a third aspect of the present invention, in addition to the means of the first or second aspect of the invention, the initial velocity vector determining means is electro-optically disposed within the tee to determine when the golf ball leaves the tee. A ball departure detection means for detecting a golf ball that leaves the tee and flies in correlation with the departure of the golf ball from the tee, which is disposed above the tee and detected by the tee departure detection means, within a predetermined time axis. a ball position detection means for detecting a three-dimensional position, and a release tee position and release time of the ball detected by the ball release detection means, and a predetermined time of the ball detected by the ball position detection means. The method is characterized in that an initial velocity vector consisting of the speed and exit angle of the ball that is hit and flies is determined from the three-dimensional position within the axis. The ball release detecting means is composed of a trigger unit consisting of, for example, a light source, a light sensor, a trigger circuit, etc., and the ball position detecting means is an overhead imaging unit composed of, for example, two CCD line scanning cameras, which is synchronized with the trigger unit. Consists of.

In addition to the means of the invention as claimed in claim 1, 2 or 3, the invention as claimed in claim 4 provides that the above-mentioned The flight trajectory of the hit golf ball whose variable cannot be calculated by the first variable calculating means is determined based on the variable calculated by the second variable calculating means. It is characterized by having a flight trajectory extrapolation means for extrapolating the flight trajectory. The flight trajectory extrapolation means includes, for example, a microprocessor containing an extrapolation algorithm.

[0011]

According to the first aspect of the invention, a flying golf ball that is hit from a tee is electro-optically observed, and the initial velocity vector of the flying golf ball is determined from the observation result and the tee position. Ru. Then, the trajectory of the flying golf ball is electro-optically tracked based on the initial velocity vector, and variables that determine the flight trajectory of the golf ball are calculated. The flight trajectory of the golf ball determined based on this variable is stored in memory, and an image of the stored flight trajectory is immediately reproduced on the display. This makes it possible to objectively evaluate the batting results.

According to the invention as set forth in claim 2, in addition to the above-mentioned effects, the range of the flight trajectory of the golf ball that flies after being hit, the wind force element, the horizontal spin (slice/hook) element, the lift element, and the deterrent A flight trajectory variable of a golf ball consisting of force elements is calculated, a ball flight trajectory simulation is performed using the calculated variables, and the simulation is superimposed on an actual or drawn image of a golf course. displayed on a display etc. As a result, it is possible to simulate the actual flight trajectory of the ball under conditions including natural factors, and it is also possible to enjoy the golf course play game while hitting the ball as if playing on a real golf course.

According to the third aspect of the present invention, the initial velocity vector determining means of the first or second aspect of the invention detects the departure of the golf ball from the tee, and further correlates to the departure of the golf ball from the tee. The three-dimensional position of the flying golf ball within a predetermined time axis is detected, and the speed of the ball is determined from the detected departure tee position and departure time of the ball and the detected three-dimensional position of the ball within the predetermined time axis. An initial velocity vector consisting of This provides an accurate initial velocity vector and allows calculation of the initial ball flight direction.

According to the invention described in claim 4, claim 1,
In addition to the effect of the invention related to 2 or 3, a golf ball whose variables cannot be calculated by the first variable calculation means due to poor long-distance lighting, poor discrimination from the background, flight obstruction due to a protective net, etc. The flight trajectory of is extrapolated based on the variables calculated by the second variable calculation means. As a result, the trajectory of the ball, which cannot be observed, can be reproduced on a display or the like.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram of main structural units according to an embodiment of the present invention. In the figure, an electro-optical device 10 includes a trigger unit 11, an overhead imaging unit 12, and a ground imaging unit 13, which will be described later, and measures the actual flight trajectory of a hit golf ball. The control and display device 14 comprises a frame grabber memory unit 15, a processing and control unit 16, a window memory unit 17, and a display monitor unit 18, which will also be described in detail below, and is configured to display the measured golf ball as described above. The flight trajectory is reproduced and displayed on a color display monitor. An overhead lighting unit 19 is provided to enhance the electro-optical contrast for measuring the movement of the ball during the early stages of flight. The wind sensor unit 20 uses an algorithm to calculate the flight trajectory of the ball.
Provided to incorporate wind power elements. A computer/printer unit 21 is additionally provided as necessary to store, statistically analyze, and print player score sheets and past data for individual use. The golf course image database unit 22 simulates a complete golf course game played using woods and irons, and is additionally provided as needed.

FIGS. 2 to 4 show the electro-optical device 1 described above.
Three units 11, 12, 13 forming 0 are shown and explained in detail. The trigger unit 11 shown in FIGS. 2(a) and 2(b) consists of two units, a main unit and a sub unit, each having a similar configuration, and two rubber tees 11-1 and 11-, which are separately arranged. Designed to fit under the 1'
will be placed. Each of them is a light source 11-, which is made of a miniaturized photodiode or laser diode, for example.
2, 11-2', reflected light detector 11-3, 11-3',
It also includes light amount change detection circuits 11-4 and 11-4'. The first rubber tee 11-1 shown in FIG. 2(a) is used by being attached to an automatic ball feeder commonly used in modern golf hitting ranges (practice ranges). , are similar in principle. The second rubber tee 11-1' shown in Figure 2(b) is provided for iron strokes where the ball is placed directly on the ground (synthetic grass mat). Then, the automatic detection circuit 11-4 (or 11-4') corresponding to the appropriate tee 11-2 (or 11-2') in use at that time and the detection logic described later detect the whiteness of the ball on the tee. Reflected light is detected,
scanned. The initial movement of the flight trajectory of the ball is notified by outputting a trigger signal in response to the fall of the reflected light detection signal when the ball leaves the tee.

The overhead imaging unit 12 shown in FIG. 3 includes two CCD line scanning cameras 3-a or two CCD-
It is configured by one of the TV short exposure cameras 3-b. Both designs are chosen alternatively, but in both cases the field of view of the camera is such that it provides stable triangulation calculations, and the field of view is such that the golf club swings within its field of view, or Geometrically designed to avoid intrusion of balls from adjacent ball-striking lanes. In the case of two CCD line scan cameras 3-a, the cameras capture a single three-dimensional plane that covers the complete range corresponding to the initial exit angle of the ball, i.e. the plane through which the flying ball always passes. It is set up as you imagine. In the case of two CCD-TV short exposure cameras 3-b,
The cameras are installed so that they mutually cover a given three-dimensional space. In that space, the ball must be displayed in at least one video frame (a "frame" represents one screen of display).
can be observed simultaneously by two cameras within a short exposure corresponding to . Thereby, triangulation is performed using the trigger signal output from the trigger unit 11 and the observation angles of the two cameras of the overhead imaging unit 12 with respect to the flying ball. This one triangulation is in principle sufficient to determine the initial velocity vector of the flying ball. Furthermore, if the device is utilized in such a way that two consecutive triangulation measurements are taken at a certain reasonable distance using two sets of CCD line scanning cameras 3-a, the trigger unit 11 is no longer needed and can be removed. Similarly, if the ball is triangulated at least twice in consecutive exposures, for example if the overhead imaging unit 12 is designed with two CCD-TV cameras, the trigger unit 11 can likewise be removed. is possible.

FIG. 4 is a diagram illustrating the functions of the ground imaging unit 13 shown in FIG. 1. Ground imaging unit 13
consists of a CCD-TV high-resolution, variable-exposure camera positioned directly below the tee point and aligned with the desired direction of the ball's flight trajectory. The field of view of the ground imaging unit 13 using this CCD-TV camera is, through the camera window 4-1, the complete range of the ball's possible initial launch angle (approximately 70 degrees above the horizontal) and the slice/hook. Sufficient azimuth range of observation angle (azimuth approximately ±20 with respect to desired center direction)
degree).

The resolution of this CCD-TV camera must be such that it can show the high probability direction of the ball with the maximum range of field of view, ie the highest possible resolution and the highest possible field of view. . The highest resolution is
It must be effective over the maximum flight trajectory range (low-climb observation angle between 10 and 20 degrees above horizontal). The ground imaging unit 13 may be divided into several CCD-TV cameras having different resolutions and partially overlapping fields of view.

The overhead imaging unit 12 and the ground imaging unit 13 in FIG. 1 generate a CCD line scanning signal or a standard video signal for a control/display device 14 consisting of units 15 to 18. In the case where the overhead imaging unit 12 is two CCD line scan cameras, the frame grabber memory unit 15 can support two analog-to-digital converters, multi-line digital RAM, and real-time frame differentiation. It consists of a multi-image frame grabber (a grabber is a type of digital image RAM that is equipped with an input/output video synchronization circuit and operates at high speed). Also,
When the overhead imaging unit 12 is configured with two CCD-TV cameras, it is provided with a dual input/multi-video frame grabber that can support real-time frame discrimination of two simultaneously input images. The processing and control unit 16 is a high speed, software driven, digital signal and image processing unit that implements object detection and tracking algorithms and calculates flight trajectory variables of the ball during the tracking process. The window memory unit 17 is
It consists of a digital RAM that stores a series of video windows in a selected order for immediate playback at will. This selected video window is a group of data of, for example, 32 x 32 bits (pixels) centering on the video signal of the ball in each frame, and is
If the storage capacity of M is, for example, 512×512 bits, 16 video windows can be stored. The display monitor unit 18 comprises a color display monitor device, which allows the player to view instant playback, golf game simulation, etc., as shown in FIG.
Or so that you can easily observe the results of your batting form.
It is tilted to face the player and is planted slightly below ground level. Overhead lighting unit 1 in Figure 1
9 is placed approximately near the overhead imaging unit 12, as shown in FIG. This overhead lighting unit 19 is
This is to make the contrast of the flying ball even clearer, and enables short-time exposure operation of the overhead imaging unit 12. Wind sensor unit 2 in Figure 1
0 outputs accurate wind measurements (speed and heading) for all corresponding practice lanes on the driving range. This generates the wind force factor required to be included in the ball flight trajectory calculation algorithm. The golf course database unit 22 of FIG. 1 is a fast-access course image database (e.g., a video desk) that stores real or depicted golf course video images.
and a display processing unit, and can simulate the flight trajectory of the ball calculated and reconstructed by the system by superimposing it on the course image.

FIG. 5 shows a flowchart of the overall processing according to the embodiment described above. This process is started by a trigger signal output by the trigger unit 11. This trigger signal determines the exit time of the ball being hit and the tee point in use at the time (a high tee for a drive shot with a wood or long iron, or
Represents a tee at ground level for short iron stroke shots. In step S51 in the figure, the overhead imaging unit 12 automatically detects and triangulates a flying ball in at least one time axis. Therefore, the processing and control unit 16 determines whether the generation of the trigger signal and the triangulation, which will be described in detail later with reference to FIG. 6, are correlated or not. If the occurrences are correlated, then in step S52, an initial velocity vector is calculated based on the time data indicated by the trigger signal, the tee point position data, and the triangulation results. Next, in step S53, the ground imaging unit 13 is started, and the image position is centered at the image position where the ball is expected to appear based on the calculation result of the initial velocity vector (the initial flight trajectory is assumed to be linear). ground imaging unit 13
A small image window (for example, an image range represented by 32 pixels in both the vertical and horizontal directions) is selected in the CCD-TV camera image, and the image of the ball flying away is captured in this window. Subsequently, in step S54, flight trajectory tracking processing is started using the initial velocity vector of the flying ball and the image position data of the ball captured by the CCD-TV camera of the ground imaging unit 13. Here, the detection algorithm is applied to video image data continuously input from the ground imaging unit 13. This input frame-by-frame video image data is compared with the initially input video frame, thereby allowing detection of changes in ball position throughout the duration of the flight trajectory. This tracking process involves measurements of wind elements to find flight trajectory range, degree of slice/hook, etc., and Kalman filters, which are optimal filters for unsteady time series derived for example based on state-space methods. This is done by adopting a model based on a variable calculation algorithm such as . In this process, in step S55, the image position of the ball is given in consecutive video frames, and a related video window is selected based on the image position, and the selected video window is stored in the window memory unit 17 of FIG. Accumulated. Next step S56
Then, it is determined whether or not the flight of the ball has ended. The end of this flight trajectory is defined by the actual or extrapolated elevation angle of the ball falling below the horizontal plane. If the flight of the ball has ended, immediate playback, simulation, or display of an arbitrary batting form is started in step S57.

In step 51, if there is no trigger signal to signal the start of triangulation, or if there is a trigger signal but the ball is not detected by the overhead imaging unit 12, that is, if there is no correlation between the trigger signal and triangulation. If not, the process proceeds to step S58. In step S58, it is determined whether there is flight trajectory data previously stored in the memory. If there is data, that is, if there is a ball hit last time, immediately step S5 is performed.
Proceed to step 7. This allows the simulation, flight trajectory display, etc. to be repeated until a new trigger signal is generated and an initial velocity vector is calculated. In addition, in step S58, if there is no flight trajectory data previously stored in the memory, it means that the first ball stroke has not been made yet, and in this case, the process returns to step S51 to detect the trigger signal. .

The ball feeding mechanism in this embodiment is similar to modern golf practice range systems used today, for example, in which the ball is automatically fed onto a rubber tee, and the rubber tee on which the ball is placed is It may be similar to a ball feeding mechanism that lifts the ball to a predetermined position through a hole in the ground (synthetic grass mat). The automatic ball feeder feeds balls by using an electro-optical mechanism consisting of a light source and a detector installed at the bottom of the rubber tee to scan changes in the reflected light from the balls leaving the tee. This is done by detecting the flight of the ball. Additionally, the ball feeder mechanism must have one ball anchorage location that can clearly define when the ball is actually placed on the tee. This allows the ball reflected light detection circuit to calculate the reflected light level (average and variation) and to select an appropriate detection threshold.

Furthermore, in the method of this embodiment, the trigger unit 11 is similar in principle to the existing electro-optical detection mechanism, but in the case of this embodiment, the detection circuit is particularly sensitive. Moreover, it is set to output a signal in exact correspondence with the detection time. This enables accurate initial velocity vector calculation.

By the way, the ball can normally leave the tee in three different conditions. That is, in the first case, the ball is hit directly from the tee point; in the second case, the player removes the ball from the high tee and replaces it with a low tee for an iron shot, or The opposite case, or a third case, is when the ball happens to fall off the tee. In the first case, as shown in FIG. 2(a), the trigger signal is generated at the signal falling edge where the detection signal changes below the detection threshold. This trigger signal is therefore correlated to the ball detection and triangulation measurements of the overhead imaging unit 12 within a reasonable amount of time. The correlation between the trigger signal and the triangulation measurements together makes it possible to calculate the initial velocity vector. In the second case, the ball is being displaced from one tee to the other, so the correlation described above does not occur within a reasonable amount of time. Therefore, the trigger signal from one tee when the ball is initially removed is ignored as a result, and from now on, the trigger unit corresponding to the other tee scans the reflected light of the ball. Then, for example, when a ball is hit from a lower tee point, a trigger signal is generated from the trigger unit corresponding to the lower tee, and it is correlated with the overhead imaging unit 12 to calculate the initial velocity vector. Make it seem possible. The correlation between these two measurements applies similarly to the determination of the third case above. That is, the generated trigger signal is ignored because it does not correlate with any triangulation measurements to which it should be associated.

FIG. 6 is a flowchart illustrating in detail the flow of the trigger detection process of the trigger unit 11 (determination process of step S51 in FIG. 5). The processing of steps S61 to S63 for the high tee and the processing of steps S61' to S63' for the low tee are simultaneously executed in parallel by time sharing. First, the process for high tees will be explained. Step S6 in the figure
1, it is determined whether the ball is placed on a high tee. This means that if there is no ball, there will be no reflected light entering the detector, and the output signal will be at the "L" level (
(See Figure 2(a)). In this case, the determination process (reflected light detection process) in step S61 is repeated. If the reflected light is detected, it means that the ball has been placed on the tee, and in this case, the process advances to step S62, and a detection threshold is calculated from the detection level at this time and the detection level when there was no ball. and set. This threshold value may be set to, for example, an intermediate value between the detection level when the ball is placed on the tee and when there is no ball. continue,
In step S63, it is determined whether a trigger signal has been output from the trigger unit 11. That is, when the detection level of the reflected light becomes below the threshold value based on the threshold value set above, the fall of the detection level is detected and the trigger signal is outputted by the trigger unit 11.
The presence or absence of the trigger signal is determined. If there is no trigger signal, steps S62 and S63 are repeated, and if there is a trigger signal, the process advances to step S64. The processing of steps S61' to S63' for a low tee is exactly the same as that of steps S61 to S63 described above. In step S64, the notification of trigger signal detection is sent to steps S63 and S63.
' is detected, and a measurement based on triangulation is performed using this information and the position information of the flying ball from the overhead imaging unit 12. Subsequently, in step S64, it is determined whether the triangulation measurement was made within a predetermined time, ie, whether it is correlated with the trigger signal. If there is a correlation, an initial velocity vector is calculated in step S66. The initial velocity vector calculation process in step S66 is exactly the same as the initial velocity vector calculation process in step S52 of the overall flowchart shown in FIG. Furthermore, if there is no correlation in step S65, the process immediately returns to the determination processing in steps S61 and S61'.

As already mentioned, if two sets of triangulation measurements by the overhead imaging unit 12 can be achieved, the initial velocity vector and the ejection time can be found independently only with this overhead imaging unit 12, so that the In this case, the trigger unit 11 is not needed for the operation of the system. Similarly, the overhead imaging unit 12 includes one CCD.
-C only for the TV camera and also for the ground imaging unit.
A CD-TV camera may be provided to perform triangulation measurements for calculating the initial velocity vector.

FIGS. 7 and 8 show the above-mentioned overhead imaging unit 12.
FIG. 2 is a flowchart illustrating triangulation processing by As mentioned above, the overhead imaging unit 12 includes two CCDs.
Either a line scan camera or two CCD-TV cameras are used to triangulate the three-dimensional position of the flying ball.

FIG. 7 shows processing using two CCD line scanning cameras. The procedure begins with a trigger signal generated by the trigger unit 11 in step S78. This process also includes steps S71 to S74 performed by one of the two CCD line scanning cameras, that is, the first camera, and step S71' performed by the other one, that is, the second camera.
The processes from S74' to S74' proceed simultaneously and in parallel. First, in steps S71 and S71', the two line scanning cameras each generate a line scanning video signal S(n, t) (n represents a pixel index, and t represents a time index). Subsequently, in steps S72 and S72', the signal is digitized, stored in memory moment by moment, and subjected to time difference by the frame grabber unit 15 (D(n,
t)). This time difference processing is sufficient to cope with the CCD response and unsteady observation field of view, and can efficiently reduce the reflected light signal of the flying ball in proportion to uncorrelated system noise (noise signal generated within the system). increase Next, in steps S73 and S73', a detection filter F(n) whose optimal gain has been determined is determined. continue,
In steps S74 and S74', this detection filter F(n
) is a differential line scanning signal D(n
, t), and this line scanning signal D(n, t)
maximizes the video signal of the observed ball against noise. The variation Var of the line scan data is calculated, and the threshold Thr is the filtered output I(n,
t). That is, S(n, t) = line scan sample of pixel n at time t D(n, t) =
S(n, t) − S(n, t−dt); dt = line sampling increment I(n, t) = F(n) CONV D(n,
t) ;CONV is the rotation, F(n) is the weight “2i+1
” represents a spatial filter of {f(-i), . ．． ．． ,f(0
),. ．． ．． , f(+i)}, Var = E {I(n, t) I(n, t)}
−E{I(n, t)} E{I(n, t)};
Here, E{} represents the statistical expected value Thr
= k Var; k is the warning message rate. If I(n, t)>Ths then I(n,
t) is a candidate pixel of the ball.

Note that the spatial filter depends on the magnification of the camera. That is, the observed size of the ball depends on the size of the ball, the distance between the ball and the camera, and the focal length of the camera. When the ball size is large, the filter is also large, and when the ball size is small, the filter is also small. The weights of the detection filter (spatial filter) are designed such that the response of the filter to the ball image signal is maximized, while the response to system noise is minimized. The optimal filter size for a line scan camera depends on whether you are observing the front or back edge of a moving ball, or alternatively the middle (widest) part of the ball. , must be changed in real time.

[0031] Furthermore, the warning message rate is a rate representing the "degree of error detection per unit time",
A constant to represent this is applied to the threshold for the detection filter output.

[0032] In this manner, when a pixel signal exceeds a threshold value at a given position within a video image, a detection flag is designated to a particular location. As a result, the observation space and observation time corresponding to the two cameras are sufficiently correlated.
Further, those that are correlated within a predetermined time from the trigger transmission of the tee trigger unit are selected as ball candidate pixel signals.

The pixel signals exceeding the threshold by the detection filter are candidate pixel signals of the ball represented within the small video window. Candidate pixel signals of balls that do not move along the predicted positions calculated by the Kalman computation process in successive video images are discarded. The indicated ball position is updated every moment as the motion variables are updated.

[0034] When the flying ball is detected by both cameras as described above, the process proceeds to step S75, where calculations based on triangulation are performed. Subsequently, in step S76,
Both calculation results based on triangulation using two cameras are compensated for geometrically, for example, the difference in the visible range of the two cameras, and the correlation between both areas is used as the calculation quality standard, and if the correlation is above a predetermined value, For example, the process proceeds to step S77, and an initial velocity vector is calculated based on the correlation between the injection time indicated by the trigger signal, the tee position used for the stroke, and the above measurement result. If it is less than the predetermined value in step S76,
Waits for the next trigger signal to occur.

Based on the initial velocity vector calculated in this way, a video window set within the field of view of the camera of the ground imaging unit 13 is designated, and the process of tracking the flight trajectory of the ball is started.

FIG. 8 shows that the overhead imaging units 12 are two C
It is a flowchart of triangulation processing when configured with a CD-TV camera. This process is also started with the trigger signal generated by the trigger unit 11 in step S89. In steps S81 and S81' in the figure, the short-time exposure CCD-TV camera video signals are digitized synchronously and continuously, and their respective images are simultaneously and immediately transferred to the frame grabber memory unit 1 in FIG.
It is stored in 5. In the next steps S82 and S82',
The digitized and stored signal is time subtracted with respect to a previously stored image corresponding to the signal. A video frame is divided into two video fields that are paired with each other (for example, in the case of a CCD-TV camera that performs standard interlace scanning, one frame is divided into two video fields).
The image field is divided into two video fields with pair-one interlacing (interlaced scanning every other scanning line).

Subsequently, in steps S83 and S83', a real-time change amount difference calculation of the image is performed for each CCD-
Calculated for the field of view of the TV camera and based on this:
A detection threshold is determined and applied to the image. Also,
The detection filter (spatial filter) is
Thresholding to optimize detection operations and minimization of alert message rates may be applied in advance.

Next, in steps S84 and S84', the image shadow points (pixels) exceeding the threshold are classified as target pixels (pixels representing a ball), and the closest target pixels are grouped together. be done. The geometric center is then calculated. Subsequently, in steps S85 and S85', a group that best matches the expected size of the ball image is selected. In step S86, the above calculated geometric center of the population is given as the center of the two geometric balls from the two cameras, from which the three-dimensional ball position is determined by triangulation calculations. Subsequent steps S87 and S88 are the same processes as S76 and S77 shown in FIG.

A procedure similar to that described above is applied to the second field of view of each camera, from which the three-dimensional position of the ball at the second exposure time is determined. The two three-dimensional ball positions are used to calculate the initial velocity vector and the initial time of injection, since the initial flight trajectory is assumed to be linear (a straight trajectory rather than a curved one). If only one triangulation is performed,
The results must then be correlated to the trigger signal, and with reasonable correlation both results can be used to find the complete initial velocity vector. Given the initial velocity vector, a flight trajectory tracking process is initiated in which a small viewing window for ball acquisition is selected within the camera field of view of the ground imaging unit 13 in which the flying ball is to be detected.

FIG. 9 is a flowchart of flight trajectory tracking processing by the ground imaging unit 13. This process begins by providing an initial velocity vector. First, in step S91, a small video window in which a flying ball is expected to appear in the next subsequent video frame is selected based on a given initial velocity vector.

As already mentioned, the Kalman filter predicts the upcoming ball position in the updated video image of the ground imaging unit 13. A small video window centered on the image coordinates shown in the subsequent video image is used for moving ball detection. this is,
In order to reduce the processing time and computational complexity for subsequent ball detection, and also to increase the probability of correct ball detection, and to reduce incorrect detection relative to other balls in the driving range. This is done to avoid this.

In step S92, the frame grabber image memory unit 15 digitizes the relevant video frame. When a flying ball is detected within the selected small image window in the next step S93, the small image window in which the flying ball was detected is stored in the memory of the window memory unit 17 in the following step S94.

Furthermore, if the ground imaging unit 13 is equipped with two or more CCD-TV cameras to increase the resolution, the ball position determined within the field of view determines which cameras are suitable for image digital processing. is selected. Similarly,
When detecting a ball using an overhead imaging unit, the two-dimensional optimal detection filter that corresponds to the expansion of the ball video signal is
It is applied to digitize the video frame corresponding to the small video window calculated to capture the ball.

This initial video frame remains in the image memory for complete flight trajectory processing and is used as the associated single image for differencing all subsequent video images.

That is, in step S95, the subsequent difference image is filtered by an appropriately sized and optimized detection filter and thresholded to extract ball candidate pixels. The size of the optimal detection filter is
As the distance of the ball increases, it decreases in subsequent video frames. There is also a decrease in the ball video signal to noise ratio as an indication of flight trajectory enhancement. This decreases throughout the flight to the point where the ball can no longer be detected. The azimuth and elevation angle of the ball observed by the camera of the ground imaging unit 13 are used to select a small image window to be stored in the window memory unit 17, and are also used for ball tracking and flight trajectory variable calculation algorithms (for example, Kalman・Used for filters). The size of the video window is updated depending on the degree of detection certainty and the measurement reliability of the tracking process. The observation angle calculated for the ball in each video frame from the ground imaging camera is calculated in step S97.
It is calculated each time by taking into account wind speed data, which will be described in detail later, based on wind speed measurements, or it is extrapolated and updated. Then, in step S96, while the elevation angle of the observed ball is greater than a given threshold, for example, horizontal (elevation angle 0 degrees), the process returns to step S92 and steps S92 to
S96 is repeated. In step S96, if the observed elevation angle falls below 0 degrees, the flight trajectory tracking process is terminated.

The flight trajectory variable calculation process based on the above-mentioned model depends on the dynamic equation of motion of the ball's flight trajectory. The main forces that determine the flight trajectory of the ball at each point during flight are (a) the force of gravity, (b) the restraining force of air resistance, (c) the lift force due to bottom spin, and (d)
The force of slicing or hooking due to side spin, and (
e) It is a wind element. The flight trajectory is determined by the forces (a) ~ (
c) when applied with a headwind or tailwind, in a plane containing the normal to the surface of the earth (see Figure 12). Similarly, when side spin or cross winds are present, the flight trajectory is
It becomes a three-dimensional gentle spatial curve. The equation of motion of the ball can be expressed by two sets of one-dimensional nonlinear difference equations with respect to time. Given the ball's initial velocity vector, the initial arrest and heave coefficient calculations, and the wind speed vector, the forward velocity and angle can be computed progressively in small time increments, thereby It is also possible to calculate the entire flight trajectory without tracking the ball inside (C.B.D.
aish,”The Physics of Ball
Game”, English Univ. Pres.
s, 1972). This equation of motion is given below.

[0047] dθ/dt = −v2/a − g s
in (θ)dθ/dt = k − g cos (
θ)/v where v: velocity with respect to the air, g: gravitational acceleration, θ: flight angle (with respect to horizontal and desired heading), t:
time, a: inhibition coefficient, k: uplift coefficient.

These equations are completed by substituting the induction time by the incremental difference approximation formula. The initial velocity vector measured by the overhead imaging unit 12 and the trigger unit 11 is "v" and "θ" including the wind speed.
Give the initial value of . The wind speed vector is calculated under each incremental calculation by decomposing the wind speed vector into two components: one component along the direction of the instantaneous ball velocity, and a second component in the normal direction. , vectorwise added to the ball velocity vector. The flight angle "θ" is calculated using the observation angle from the camera of the ground imaging unit 13 (see FIGS. 10 and 11). The wind component along the instantaneous ball velocity vector mainly affects the lift and restraining force exerted on the flying ball, while the normal component rotates the plane of motion. For the trajectory distance that the flying ball is traversing, in other words completing incrementally, the velocity with respect to the ground should be used rather than the velocity with respect to the air. Lift and deterrence variables (“a” and “k” respectively)
'') are non-linear functions of velocity that are not well-defined, from which it becomes necessary to track and calculate these variables iteratively. Observation angles from the ground imaging unit 13 in successive video frames are factored into the calculation process and, together with preliminary approximation calculations of deterrence and lift, allow for more accurate discovery of flight trajectory range and slice/hook factors. . FIG. 10 shows a flowchart of immediate playback display processing. This process begins when the end of the trajectory is verified. The detected and calculated ball image position is
It is used to reproduce the small image window stored in the memory unit 17 into an image frame correspondingly stored in the display monitor unit 18.

FIG. 11 shows a flowchart of golf course game simulation processing. This process also
Triggered when the end of the trajectory is verified. The three-dimensionally calculated ball position through the trajectory is graphically and realistically displayed and superimposed on the relevant golf course image from unit 22.

[0050]

According to the present invention, the flight trajectory of a golf ball in three-dimensional space can be analyzed and calculated by electro-optical measurement, and an image of the flight trajectory of the golf ball can be immediately reproduced and displayed. Slices and hooks can also be used in cases where it is difficult to see the ball far away, when the ball is difficult to identify due to a crowded background, when the installation size of the protective net is insufficient and the flight of the ball is obstructed, etc. Since the flight trajectory of the golf ball can be observed as a video image from the end to its destination, it can be used even when the lighting is insufficient at night, when the background is crowded and the ball is difficult to identify, or when the driving range is small. Regardless, the batting results can be observed until the end in accordance with the actual results, allowing practice to improve the corrective effect. In addition, since the simulation can be superimposed on an actual or drawn golf course image, you can progress as if you were actually hitting the ball on a golf course and know the result of the ball. It is also possible to enjoy the game alone or with several people. Furthermore, since the image of the ball in flight is stored using a minimum amount of digital video memory, the effectiveness of the storage device is improved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of main structural units according to an embodiment of the present invention.

FIGS. 2(a) and 2(b) are diagrams illustrating a trigger unit.

FIG. 3 is a diagram illustrating an overhead imaging unit.

FIG. 4 is a diagram illustrating the functions of a ground imaging unit.

FIG. 5 is a flowchart of overall processing according to this embodiment.

FIG. 6 is a flowchart illustrating trigger detection processing in detail.

FIG. 7 is a flowchart illustrating triangulation processing when the overhead imaging unit is composed of two CCD line scanning cameras.

FIG. 8 is a flowchart of triangulation processing when the overhead imaging unit is composed of two CCD-TV cameras.

FIG. 9 is a flowchart illustrating flight trajectory tracking processing by the ground imaging unit.

FIG. 10 is a flowchart illustrating immediate playback display processing.

FIG. 11 is a flowchart illustrating golf course game simulation processing.

FIG. 12 is a diagram illustrating a golf ball trajectory calculation method. 10 Electro-optical device 11 Trigger unit 12 Overhead imaging unit 13 Ground imaging unit 14 Control and display device 15 Frame grabber memory unit 16 Processing and control unit 17 Window memory unit 18 Display monitor unit 19 Overhead lighting unit 20 Wind sensor unit 21 Computer/printer unit 22 Golf course database unit 11-1, 11-1
' Rubber tees 11-2, 11-2' Light sources 11-3, 11-3' Reflected light detectors 11-4, 11
-4' Light amount change detection circuit 111-5 Synthetic grass 3-a Two CCD line scanning cameras 3-b Two CCD-TV short exposure cameras 4-1
camera window

Claims (4)

[Claims] 1. An initial velocity vector for electro-optically observing a golf ball that is hit and flying from a tee and determining an initial velocity vector of the golf ball that is hit and flying from the observation result and the tee position. a means of determining;
A flight trajectory of the golf ball by electro-optically tracking the trajectory of the golf ball flying in an observable state in an observation direction determined based on the initial velocity vector of the golf ball determined by the initial velocity vector determining means. a first variable calculating means for calculating a variable that determines the first variable calculating means; and a flight trajectory of the golf ball determined based on the variables calculated by the first variable calculating means, which is stored in a memory. A golf batting training and simulation method, comprising: video reproduction means for immediately reproducing an image of the flight trajectory of the golf ball on a display. 2. A step for calculating a flight trajectory variable of the golf ball, which includes a range of the flight trajectory of the golf ball flying after being hit, a wind force element, a lateral spin (slice/hook) element, a lift force element, and a deterrent force element. 2, further comprising a variable calculating means 2, which simulates the flight trajectory of the hit golf ball using the calculated variables, and converts an image of the simulated golf ball flight trajectory to an actual or drawn golf course. Claim 1 characterized by comprising an image superimposing means for superimposing on an image.
Ball hitting training and simulation method described. 3. The initial velocity vector determining means includes a ball departure detection means that is electro-optically disposed within the tee and detects when the golf ball leaves the tee, and a ball departure detection means that is disposed above the tee and detects the departure of the golf ball from the tee. ball position detection means for detecting a three-dimensional position within a predetermined time axis of a golf ball that leaves the tee and flies in correlation with the departure of the golf ball from the tee detected by the means; The speed and ejection of the ball that is hit and flies from the departure tee position and departure time of the ball detected by the means and the three-dimensional position of the ball within a predetermined time axis detected by the ball position detection means. The golf batting training and simulation method according to claim 1, characterized in that an initial velocity vector consisting of an angle is determined. 4. The flight of the hit golf ball in which the first variable calculation means is unable to calculate the variable due to poor long-distance lighting, poor discrimination from the background, flight obstruction due to a protective net, etc. 2. The method of claim 1, further comprising flight trajectory extrapolation means for extrapolating the flight trajectory of the golf ball whose trajectory cannot be calculated based on the variables calculated by the second variable calculation means. Golf batting training and simulation method according to 3.