JPS6013469B2 - Ball speed detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical ball speed detection device suitable for detecting the speed of a ball during baseball pitching practice or the like.

A method for optically measuring the speed of a baseball ball is already known as an application of optical sensors.

By the way, in the conventional pole speed detection method, "a large number of light beams are arranged in a grid pattern at a first position, a large number of light beams are arranged in a grid pattern at a second position, and The passage of the ball is detected with
The speed was determined by dividing the distance L between the position and the time T. However, since the light beams had to be arranged in a grid pattern, the device became complicated and large. In order to solve this type of drawback, it is conceivable to detect the movement of the bozzle from the side using a two-dimensional image sensor to detect the speed.

However, even if the ball speed is the same, the measurement results will be different depending on whether the ball is close to the sensor or far from the sensor. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a ball speed detection device that can be made smaller, lower in cost, and more accurate.

To achieve the above object, the present invention provides a photosensitive portion that is fixedly arranged on an extended plane of a predetermined plane that can be indicated by xy coordinates, and whose one-dimensional arrangement direction coincides with a first straight line on the extended plane. a first one-dimensional element arranged such that the photosensitive section is arranged so that the length of the photosensitive section in the {}-dimensional arrangement direction is 4. smaller than the length of the predetermined plane in the x-axis direction and the y-axis direction; an image sensor fixedly installed on the extension plane and arranged such that the one-dimensional arrangement direction of the photosensitive portion thereof coincides with a second straight line having a predetermined angle with respect to the first straight line; a second one-dimensional image sensor formed such that the length of the photosensitive portions in the one-dimensional array direction is smaller than the length of the predetermined plane in the x-axis direction and the length in the y-axis direction; and at least the predetermined plane a first one-dimensional image sensor formed and arranged such that images of the ball at all positions of the ball can be obtained on the first one-dimensional image sensor;
a second lens formed and arranged such that it is possible to obtain an image of the ball on the second one-dimensional image sensor at least at all positions of the predetermined plane; a clock signal generator for driving the first one-dimensional image sensor and the second one-dimensional image sensor in synchronization; a first image forming point position signal forming circuit that forms a signal indicating the image forming point position on the original image sensor; a second image forming point position signal forming circuit that forms a signal indicating the image forming point position of the image forming point position, and a second image forming point position signal forming circuit that generates a signal indicating the image forming point position of a ball position calculation circuit that calculates the x (or y) coordinate position of the passing ball; and a ball position calculation circuit that calculates the x (or y) coordinate position of the passing ball;
), a time measurement circuit that measures the time T required for the ball to cross the photosensitive area of the -dimensional image sensor, and the time T measured by the time measurement circuit, the width a of the photosensitive area, and the ball position calculation circuit. The pole speed V is set based on the ball's coordinate position x (or y), where m changes depending on the pole position x (or y). The present invention relates to a ball speed detection device that includes a speed calculation circuit that calculates the reduction ratio of an image formed through the ball, and a speed output device that displays or records the output of the speed calculation circuit.

According to the present invention, it is no longer necessary to arrange a large number of light beams in a lattice pattern as in the prior art, making it possible to make the device four-dimensional and reduce costs.

Furthermore, since the speed is measured taking into account changes in the position of the ball in the x (or y) direction, accuracy is increased. Embodiments of the present invention will be described below with reference to the drawings.

Sensors in an apparatus for determining a baseball strike ball according to an embodiment of the present invention are arranged as shown in FIGS. 1 and 2. As is clear from FIG. 1, which shows the direction of home plate from the pitcher's or catcher's side, and FIG. 2, which shows the state seen from above and below the base plate, the first one-dimensional image sensor is The second one-dimensional image sensor 2 is placed on the base board 3 at a position on the base board 3 where the batter stands. A predetermined plane 4 surrounded by a chain line is a strike zone, and is an area across which the ball passes. In this embodiment, since the center point Po of the predetermined plane 4 is set as the origin of the xy coordinates, each part in the predetermined plane 4 can be indicated by a cutting coordinate point. A first one-dimensional image sensor 1 is fixedly installed at a position separated from the origin Po by a distance Yo in the y-axis direction, and the origin P. A second one-dimensional image sensor 2 is fixedly installed at a position separated by a distance Xo in the direction of the text axis.
The first straight line 5 and the second straight line 6 drawn along the respective sensors 1 and 2 are straight lines included in the extension plane of the predetermined plane 4, and the first straight line 5 is parallel to the x-axis. , also the second
A straight line 6 is drawn parallel to the y-axis. The one-dimensional arrangement direction of the photosensitive portions of the first and second one-dimensional image sensors 1 and 2, that is, the readout scanning direction is along the first and second straight lines 5 and 6.
is consistent with

In this embodiment, since the first straight line 5 and the second straight line 6 are perpendicular to each other, the one-dimensional arrangement direction of the photosensitive parts of the first one-dimensional image sensor 1 is the same as that of the second one-dimensional image sensor. It is shifted by 90 degrees with respect to the one-dimensional arrangement direction of 2. Furthermore, the first
As is clear from the drawing, the length of the photosensitive portion of the second one-dimensional image sensor 2 in the one-dimensional arrangement direction is shorter than the length of the predetermined plane 4 in the x-axis direction and the length in the y-axis direction. death,. However, the first and second lenses 7 and 8 are located between the predetermined plane 4 and the first and second one-dimensional image sensors 1 and 2.
are arranged, and since these have a convex lens configuration, even if the ball position changes at least within the predetermined plane 4,
It is possible to obtain an image of the ball at all locations in a given plane 4 on each sensor 1,2. The first lens 7 having a focal length fy is arranged at a distance By from the first one-dimensional image sensor 1 with its optical axis coincident with the y-axis. Further, the second lens 8 having a focal length fx is arranged at a distance BX from the second one-dimensional image sensor 2 with its optical axis aligned with the x-axis. The first and second illumination rays L are indicated by dashed lines in FIG.
and L2 are arranged to face the pair of sensors 2, and provide bias light to the sensors 1 and 2 as required.

Depending on the external light conditions and the reflection of the ball, this illumination light beam L,
. In this embodiment, the first and second one-dimensional image sensors 1 and 2 used in the apparatus shown in FIG. As shown, photosensitive sections A, .about.An are arranged linearly, that is, one-dimensionally, and these photosensitive sections A, .about.An are coupled via transfer gates G to a CCD serving as a readout register. That is, the charges accumulated by irradiating light onto the photosensitive parts A, ~An formed by MOS capacitors are transferred to the CCD via the transfer gate G, and transferred by the CCD as a readout register. . Figure 3 shows the entire detection device, and shows the first
The second one-dimensional image sensors 1 and 2 are shift-driven for scanning or reading by clock pulses of, for example, 40 kHz from a common clock signal generator 10.

Now, for example, at a certain point, the first one-dimensional image sensor 1
If an image of the ball is obtained on the light receiving portion A3 shown in FIG. 4, an output is obtained at time t3 as shown in FIG. 5A, for example, by a predetermined readout scanning shift operation. - Since there is a predetermined correspondence between the output generation point and the photosensitive area during the scanning period (to to tn), it is easy to know the imaging position (exposed or non-exposed position) based on the output generation point. I can do it. The second one-dimensional image sensor 2 also provides an output as shown in FIG. 5B, for example, so that the imaging position can be easily determined. The outputs read from the pair of sensors 1 and 2 are waveform-shaped by first and second waveform shaping circuits 11 and 12, and sent to first and second imaging point position signal forming circuits 13 and 14. .

The first imaging point position signal forming circuit 13 sets the center point of the first one-dimensional image sensor 1 as a zero point, and from this, the first imaging point position signal forming circuit 13
The right side of the straight line 5 is the X axis, and the left side is the -X axis,
This is to obtain imaging point position data x at a predetermined time. Further, the second imaging point position signal forming circuit 14 sets the center point Yo of the second one-dimensional image sensor 2 as a zero point, and from this, the upper side of the second straight line 6 is the Y axis, and the lower side is the −Y axis. , to obtain imaging point position data Y at a predetermined time point. Arithmetic circuit 15 into which data X and data Y are input
are the data X and data Y obtained by the detection, the focal length fy of the first lens 7 stored in advance in the memo
, the focal length fX of the second lens, the distance By between the first lens 7 and the sensor 1, the distance Bx between the second lens 8 and the sensor 2, the distance Yo from the origin Po of the xy coordinates to the sensor 1, and the origin The following calculation is performed based on the distance from Po to sensor 2. X=(BfX+QY)
X...'1} Formula fXfy+XYy=
(Qfy+8x)Y...[2] Formula, however, Q=F-(fx10Bx), 8=Yo-(fy+B
y).

Coordinate data x, y indicating the position of the ball in xy coordinates determined by this arithmetic circuit 15 is sent to a course determining circuit 16 at the next stage.

Since data indicating the strike course, that is, the predetermined plane 4, is stored in the memory in advance in the course determination circuit 16, the data indicating the strike course is compared with the detected coordinate data x and y, and the detected data x , y, that is, the ball position is within the predetermined plane 4.

An output device 17 connected to the output of the course determination circuit 16 notifies the determination result using a light emitting element and a buzzer, and records the determination result in a data recorder as necessary.

Note that the arithmetic expression {1} and the leg in the arithmetic circuit 15 are calculated as follows. First, the first and second lenses 7, 8
The formula showing the imaging point positions X and Y obtained through the equation is as follows.

fy X=-XXY.

-y-soyfy =-×X.

-y) -y=-zoshi skin {3' fX =・yL Y=-yXX.

10X-Evening×X+(FusoX)=-mi
...{4}×10Q However, let x=fx10Bx Soy=fy+By Q=Fy×B=Yo−Soy.

(From 4 wipes, y=-埜＄,Y...{5'
fX [From 3 wipes, sentence=-stop I. x...■
fy{Substituting equation 61 into equation '3' yields the following equation.

．． -y (10 seas) = X3- & YfXfy y = Judo Omotaku -Y - (Shizukumoe three ships) -Y - - - - - (71'5}
By substituting the formula into the formula (■), the following formula is obtained.

．． ．． X (10 crocodiles) = -4 evil xfXfy
Equation (8) is obtained, which is the same as equation '1}, and [7
} formula is obtained.

A time measuring circuit 18 connected to the second one-dimensional image sensor 2 through the waveform shaping circuit 12 measures the time T required for the image of the ball to cross the photosensitive part of the sensor 2 based on the output of the sensor 2. It is a circuit.

That is, in this case, the sensor 2 has a photosensitive portion 31 having a width a as shown in FIG.
3, if scanning across the photosensitive section 31 and reading is done in the direction of the arrow 34, then the ball image 3
This circuit calculates the required time T from the time when the center of 2 passes the left end of the photosensitive section 31 to the time when it passes the right end. To explain the measurement of this time T in more detail, if the width a of the photosensitive section 31 is, for example, about 0.43 skin, then while the ball image formation 3 passes through the photosensitive section 31, the reading scan in the direction of the arrow 34 is performed. Performed multiple times.

As a result, in response to the passage of ball image 32, FIG.
As illustrated in t. An output pulse is obtained for each scan at times . Therefore, this pulse train is made into a rectangular wave as shown in FIG. 7B, and the time T from the rising time t to the falling time t2 is measured. If it is assumed that the ball always follows the same course, the moving speed of the ball can be determined by a/T, but in reality, the ball's course is different, so correction is made according to the course. For this purpose, a speed calculation circuit 19 is provided, to which time data T from the time measurement circuit 18 and ball coordinate position data x from the position calculation circuit 15 are input.

The internal memory of the speed calculation circuit 19 stores the distance from the origin Po to the sensor 2 in FIG. 1 and the distance Bx between the lens 8 and the sensor 2, so data x indicating the ball position in the x-axis direction is stored. Given, the reduction ratio m of the ball, its image formation, and & is determined by m = Taiko.

Next, by manipulating the width a of the photosensitive section 31 that has been stored in the internal memory in advance, the distance V of the ball is determined where v=fort. If the velocity V is determined in consideration of the length 4 and the ratio m in this manner, the ball velocity can be accurately detected regardless of the change in the position of the ball in the x-axis direction. The detected speed determined by the speed calculation circuit 19 is sent to a speed display in the speed output device 20 and displayed, and is recorded by a data recorder if necessary.

As is clear from the above, according to this embodiment, speed detection is possible using the one-dimensional image sensors 1 and 2.
The device becomes smaller and lower in cost.

Furthermore, since the speed is detected with the change in the ball's x-axis direction corrected, accurate values can be obtained.

Furthermore, it becomes possible to use the sensors 1 and 2 for course determination, and it becomes possible to easily perform both course determination and speed detection. Also, the photosensitive part 31 of one sensor 2
Since the speed is determined by measuring the time it takes for the object to cross, the speed detection mechanism is extremely simplified. Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be further modified.

For example, instead of the CCD one-dimensional image sensor, 2, a plurality of photodiodes D,, D2, shown in FIG.
...Dn, MOS transistors Q, , Q2, ...Qn of FET structure connected in series to these, respectively, and this M
A scanning circuit SR having a shift register configuration that controls OS transistors Q, ~Qn, and MOS transistors Q, ~Qn.
A solid-state image sensor consisting of a fin source E that applies a voltage via a load resistor R to a series circuit of photodiodes D, -Dn, and an OCT provided via a capacitor C may be used. The photodiodes D, -Dn are linearly arranged, for example, along the first straight line 5 or the second straight line 6 in FIG. Further, as shown in FIG. 9, two one-dimensional image sensors 2a and 2b are arranged at a predetermined interval a,
Preferably, the ball image is formed so as to traverse, for example, from left to right through a common lens 8, and after the ball image 32 cuts off the left end of the photosensitive section 31a of the first sensor 2a, the ball image forms on the second sensor. Alternatively, the time T required for the light to cross the right end of the photosensitive portion 31b of 2a may be determined, and the calculation V=m·a/T may be performed.

This further increases accuracy. In this case, the photosensitive section 3
1a and 31b are equal to the photosensitive portion 31 in FIG. 6, and the distance a is equal to the width a in FIG. Further, in the embodiment, the time T is determined by the Y-axis sensor 2, but the time T may be determined by the X-axis sensor 1, and changes in the ball in the y-axis direction may be corrected when detecting the speed.

In addition, sensors 1 and 2 are not placed on the x-axis or y-axis as shown in the figure, but one sensor is placed on the straight line represented by y = x, and one sensor is placed on the straight line represented by y = -x. It may be placed in

At this time, the arrangement direction of the photosensitive parts is made to coincide with y=x and the direction orthogonal to y=-x. Also, sensors 1 and 2 are on the base board 3.
It may be arranged within or substantially in the same plane as this.

[Brief explanation of drawings]

FIG. 1 is a front view showing the sensor portion of a baseball ball movement state detection device according to an embodiment of the present invention, FIG. 2 is a plan view of the sensor portion of FIG. 1, and FIG. 3 is a front view of the ball movement state detection device. A block diagram showing the whole, Fig. 4 is a principle diagram of a CCD one-dimensional image sensor, Fig. 5 is a pair of sensors 1,
2 is a waveform diagram showing the output from 2. FIG. 6 is an explanatory plan view of the sensor of FIG. 1, FIG. 7A is a waveform diagram explanatory of the output when the image crosses the sensor of FIG. 6, and FIG. 7B is a diagram of FIG. 7A. FIG. 3 is a waveform diagram showing a state in which the waveform of FIG. FIG. 8 is a circuit diagram showing a modification of the image sensor. FIG. 9 is a plan view showing the arrangement of sensors in a modified example. In the symbols used in the drawings, 1' indicates the first one-dimensional image sensor,
2 is a second one-dimensional image sensor; 4 is a predetermined plane; 5 is a second one-dimensional image sensor;
is the first straight line, 6 is the second straight line, 7 is the first lens, 8
10 is a second lens, 10 is a clock signal generator, 13 is a first imaging point position signal forming circuit, 14 is a second imaging point position signal forming circuit, 15 is an arithmetic circuit, 16 is a course determination circuit, 17 is an output device, 18 is a time measurement circuit, 19 is a speed calculation circuit, and two speed output devices. Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 9 Figure 3 Figure 7 Figure 8

Claims (1)

[Claims] 1 fixedly arranged on an extension plane of a predetermined plane that can be indicated by The length in the one-dimensional array direction is x of the predetermined plane
a first one-dimensional image sensor formed to have a length smaller than the length in the axial direction and the length in the y-axis direction; , and the length of the photosensitive portion in the one-dimensional arrangement direction is equal to the length of the predetermined plane in the x-axis direction and the length in the y-axis direction. a second one-dimensional image sensor formed to be smaller than the first one-dimensional image sensor; a first lens formed and arranged;
a second lens formed and arranged so as to be able to be obtained on the one-dimensional image sensor, and driving the first one-dimensional image sensor and the second one-dimensional image sensor in synchronization. and a first imaging point position signal generator for forming a signal indicating the imaging point position on the first one-dimensional image sensor based on the output of the first one-dimensional image sensor. a second image forming point position signal forming circuit that forms a signal indicating an image forming point position on the second one-dimensional image sensor based on the output of the second one-dimensional image sensor;
a ball position calculation circuit that calculates the x (or y) coordinate position of a ball passing across the xy plane based on the output signals of the first and second image forming point position signal forming circuits; or a time measuring circuit that measures the time T required for the ball to cross the photosensitive part of the second (or first) one-dimensional image sensor based on the output of the first one-dimensional image sensor; Based on the time T measured by the circuit, the width a of the photosensitive section, and the coordinate position x (or y) of the ball obtained from the ball position calculation circuit, the ball speed V is calculated as V=ma/T (where m is the ball position). x
(or a reduction ratio of an image formed through the second (or first) lens that changes depending on y); and a speed output that displays or records the output of the speed calculation circuit. A ball speed detection device consisting of a device;