JPH06335548A - Object collision position detecting device - Google Patents

Abstract

PURPOSE:To provide the device used for training and a play of every shot game such as an approach shot of golf, shooting using a play gun, or batting of baseball, etc. CONSTITUTION:A target screen 12 is formed so as to be opposed to a position 16 for projecting a ball 17, etc., and in at least three parts in its periphery and the projecting position, microphones 101-105 for detecting a collision sound of the ball 17 are formed. By analyzing a detection time of each microphone in a control part 14, a flying time of the ball 17 and a collision position on the target screen, and a track of the ball 17 are calculated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device that can be used as a golf (particularly approach) or shooting practice device, a game device, or the like.

[0002]

2. Description of the Related Art The techniques required for golf competition are a full shot for hitting the ball in the correct direction as far as possible, an approach shot for hitting the ball in the correct direction and distance, and a green shot. You can think of it as a putt for putting in the hall. Since it is said that the average number of shots of full shots, approach and putts are almost the same for general golfers, it is necessary to practice each of these techniques equally in order to raise the golf score.

[0003]

[Problems to be Solved by the Invention] Of these, full shots can be practiced at golf driving ranges generally called "unleashed" provided at various places, and putts are also dedicated driving ranges attached to the golf driving range. You can easily practice with a commercially available pad practice mat. In the approach shot, a distance (generally 100 m or less) shorter than the maximum flight distance of the club to be used must be struck so that the direction and distance are accurate while adjusting the force. Therefore, of course, it is not possible to practice together at the putt practice area, while on the other hand, even in the “unattended” practice area, the “unattended” practice area is generally designed to mainly practice driver technology. , It is not suitable for practice of approach shots that require checking the whereabouts of the ball accurately at a relatively short distance. In addition, there are almost no practice fields where you can practice the height difference between the hitting point and the green that normally exists in actual golf courses.

Although various types of golf practice devices that do not take up a lot of space have already been devised, the practice devices that can be purchased in general households are mainly those for form acquisition and practicing, except for expensive commercial devices. Only a practice net made of pipes and nets or a bat practice mat that requires a large yard can hit a real ball.

Therefore, the present invention solves the above-mentioned problems and efficiently takes golf approach shots that have been difficult in the past.
Moreover, it is an object of the present invention to provide an object collision position detection device that enables the realization of a shot practice device that makes it possible to practice happily. The present invention utilizes such an object collision position detection device to perform shot practice in various sports such as baseball batting and pitching practice and shooting practice using a play gun, as well as golf practice. It also intends to realize a device that can be used for throwing practice and play.

[0006]

The object collision position detection device according to the present invention made to solve the above-mentioned problems is a) collision sound detection which is placed at least at three places other than the same straight line around the detection area. And b) an arithmetic means for calculating an object collision position in the detection area based on the time when the collision sound is detected by each collision sound detection means.

In addition to the above, d) an emission time detection means for detecting the time when a collision object is emitted from a predetermined point, and e) a time and an emission time when the collision sound is detected by each collision sound detection means. Based on the ejection time detected by the detection means, the movement time from the ejection time of the object at the ejection point to the collision time of the object is calculated, and the collision time is calculated from the movement time and the object collision position calculated by the calculation means. It may be provided with a second calculation means for calculating the trajectory of the object up to and the virtual trajectory after the collision.

A shot practice apparatus according to the present invention made to solve the above-mentioned problems by using such an object collision position detection apparatus includes: a) a target screen composed of a sheet stretched over a frame; ) At least three collision sound detection means arranged around the target screen; and c) Based on the time when the collision sound is detected by each collision sound detection means, the number of collisions of the projectile from the time point of ejection of the projectile at the ejection point It is characterized by comprising a flight time up to the point of collision with the target screen and a calculation means for calculating the collision position of the flying object on the target screen.

In addition to the above, d) an ejection time detection means for detecting the ejection time of the flying object at the ejection point provided in front of the target screen, and e) the flight time of the flying object and the collision position, A second calculation means for calculating the trajectory of the flying object until the collision with the target screen and the virtual trajectory after the collision may be provided. Further, display means (display) for displaying the collision position of the flying object on the target screen, the trajectory of the flying object, and the like, which are the results calculated by the calculating means or the second calculating means, or the sheet of the target screen can be displayed. The collision target point and the score area may be drawn.

[0010]

In the object collision position detecting device of the present invention, when an object collides with another object within the detection area, each collision sound detecting means detects the collision sound generated at the time of the collision. The calculation means specifies the time when each collision sound is detected (collision sound detection time) based on the detection signal from each collision sound detection means,
The collision position is calculated using each collision sound detection time and a predetermined sound velocity value. Since the collision sound detection means are placed at least at three places around the detection area that are not on the same straight line, in this calculation, according to the same principle as the determination of the epicenter of the earthquake,
The position of the collision point of the object within the detection area (object collision position) is calculated. Note that the sound velocity value used here may be a standard value determined in advance by referring to a science chronology and the like, or it may be used. The standard sound velocity value may be corrected. Furthermore, by using four or more collision sound detecting means, the sound velocity is included in the unknown number for calculation,
It is also possible to simultaneously calculate the sound velocity and the distance from the collision position to the three collision sound detecting means.

The positional relationship between the exit point of the object and the collision detection area is determined when the exit point and each collision sound detecting means are installed and is known in advance. Therefore, from the moving time of the object and the collision position, The trajectory of the object can be determined.
Since the shape of this trajectory does not depend on whether or not there is a collision, if the object did not collide, the virtual trajectory that the object moved can also be obtained. The second calculation means performs this trajectory calculation. That is, the movement time is calculated based on the detection time of the collision sound and the ejection time of the object, and the trajectory of the object (including the virtual trajectory) is calculated from the movement time and the object collision position calculated by the calculation means.

The shot practice apparatus of the present invention utilizes the above-mentioned object collision position detection apparatus, and its operation is as follows. At the shooting point, the player hits the target screen, hits a ball with a club when practicing a golf approach shot, or pulls a ball by triggering when shooting with a gun. The ejected projectile collides with the target screen and produces a collision sound there. This collision sound is detected by three collision sound detecting means arranged around the target screen (conveniently fixed to the frame, but not necessarily sticking to it). The calculating means identifies the time when each collision sound is detected based on the detection signal from each collision sound detecting means,
The position of the collision point on the target screen is determined according to the same principle as the determination of the epicenter of the earthquake using a predetermined sound velocity value. Note that the sound velocity value used here may be a standard value determined in advance by referring to a science chronology and the like, or it may be used. The standard sound velocity value may be corrected by. Further, by using four or more collision sound detecting means, it is possible to calculate the sound speed by including it in the unknown and to simultaneously calculate the sound speed and the distance from the collision position to the three collision sound detecting means.

The ejection time detection means detects the ejection time by, for example, detecting a hitting sound in the case of a golf practice device, or electrically detecting a trigger action or a bullet action in the case of gun shooting. This emission time detection signal is sent to the calculation means. The ejected projectile (a struck ball, a shot bullet, etc.) flies toward the target screen in a trajectory depending on the initial velocity at the time of ejection, the ejection angle, etc., and after a predetermined time, a certain point on the target screen ( Collision point). The collision position on the target screen is determined by the above method, and the collision time on the target screen is also easily calculated from the above method (since the collision position and the sound velocity are calculated). The positional relationship between the ejection point and the target screen is determined when the target screen and the ejection point are installed and is known in advance, so the flight time of the flying object (this is the detected ejection time and the calculated collision time). It is possible to determine the trajectory of the projectile from the coordinates of the collision point) and the coordinates of the collision point.
Since the shape of this trajectory does not depend on whether or not there is a collision, it is possible to obtain the virtual trajectory that the flying object flew if it did not collide with the target screen. The second calculation means performs this trajectory calculation. The calculation result by the calculation means and the second calculation means can be notified to the player in various forms such as sound, printout on paper, etc. in addition to the display means (display) such as CRT and LCD. Based on the output result, the player can judge whether his or her shot is as desired, and can use it for the practice of the next shot.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the entire golf approach shot training apparatus which is an embodiment of the present invention (hereinafter referred to as "Example 1"). In the golf approach shot practice device of the present embodiment, a target screen in which a sheet 12 made of cloth, resin or a composite material thereof is stretched over a substantially square frame 11 is used. The sheet 12 may include a reinforcing material (linear or net-like) such as a metal wire, glass fiber, carbon fiber or the like. The size of the target screen (seat body) is about 1-2 m
The frame 11 may be made of approximately four sides, and as the frame 11, an aluminum or steel drawn material, a pipe, or the like (a lightweight aluminum pipe is suitable in consideration of handling). By appropriately adjusting the material and the tension of the seat 12, most of the kinetic energy of the ball 17 hitting the seat 12 can be absorbed, and the ball 17 can be made to fall almost directly under the seat.

An example of the structure of the seat 12 and the frame 11 will be described in detail below with reference to FIGS. As shown in FIG. 8, at the upper portion of the sheet 12, the upper end of the sheet is sewn or adhered in a bag shape over the entire length in the width direction, and the upper bar 121 is passed through the bag. The width of the lower part of the seat 12 is slightly narrowed to form a skirt portion 13. Seat 12 body and skirt 13
A sheet-like space extending in the width direction is formed at the boundary portion between the sheet 12 and a back cloth (plastic sheet or any other sheet) 123 sewn or adhered to the sheet 12 and extends in the width direction. Pass the lower bar 122 through. The lower bar 122 is slightly protruded from the seat 12 main body and the skirt portion 13 to the left and right. On the back side of the skirt portion 13, a sponge 125 is fixed (bonded) to the seat 12 (skirt portion 13) only by the lower portion 126.

The frame 11 is, as shown in FIG. 9, an upper beam 111 made of aluminum drawn material, and the left and right columns 1.
12 and foot 113. A cross section of the upper beam 111 is shown in FIG. The upper bar 121 fixed to the upper portion of the seat 12 has a predetermined space 111a in the upper beam 111.
(This space 111a is provided over the entire length of the upper beam 111), so that the seat 12
Are suspended from the upper beam 111.

As shown in FIG. 10, in this embodiment, the left and right columns 112 use the same members as the upper beam 111,
The right and left sides of the seat 12 are housed in a space 112b (slit) in which the seat 12 is suspended when used as the upper beam 111. The inlet 112c of the slit 112b is narrowed to a width that is slightly wider than the thickness of the sheet 12, but the inside has a width that allows the sheet 12 to be sufficiently wavy. The left and right ends of the lower bar 122 (portions protruding from the left and right of the seat 12 and the skirt portion 13) are provided in another space 112d inside the left and right columns 112.
Insert in (slot). Since the slot 112d is also provided over the entire length of the left and right columns 112, the lower bar 122 can be freely moved up and down.

With the above structure, the ball 1 is placed on the seat 12.
The lower bar 1 at the lower end of the seat body when the vehicle 7 collides
Since seat 22 can move up along slot 112d, seat 12 can flex backwards, absorbing most of the kinetic energy of ball 17. As a result, the ball 17 falls almost directly under the seat. Therefore, there is no danger of the ball 17 returning to the player at a high speed and causing injury. Moreover, the seat 12 is the ball 1
Since it is always stretched in a flat shape except when the collision occurs, it is possible to practice accurate hitting when drawing points for points. Further, when the collision force of the ball 17 is strong, the left and right sides of the seat 12 may be pulled toward the center side, and the left and right sides of the seat 12 may come off the slits 112b.
Since the entrance of the slit 112b is narrowed and the inside thereof is wide, the sheet 12 cannot be corrugated in the narrow portion 112c of the entrance of the slit 112b, and the corrugated portion is corrugated only in the wide portion, so that the corrugated portion is wedge-shaped. It serves to prevent the slit 112b from coming off. Therefore, it is desirable that the width of the inside of the slit 112b is made larger than the wavy width of the sheet 12.

The ball 17 which has fallen is first sponge 12
The drop energy is absorbed by 5 so that it does not jump greatly. Then, as shown in FIG. 1, by extending the lower end 13 of the sheet 12 constituting the target screen to the front side, the sheet 12 automatically returns to the hitting point. Therefore, the golf balls can be collected efficiently. The target screen sheet 1
Instead of extending 2 directly to the lower side, a ball returning seat (mechanism) may be attached separately. Also, FIG.
As shown in, a ball focusing frame 20 that narrows from the lower end of the sheet of the target screen toward the hitting point may be provided. At this time, by fixing the end portion of the ball focusing frame 20 on the target screen side to the lower end of the frame 11, it is possible to prevent the ball 17 from escaping, and at the same time, the effect of fixing the ball focusing frame 20 and making it self-supporting can be obtained. . 1 and 7, the trajectory 18 of the ball 17 from hitting at the hitting point to hitting the target screen and returning to the hitting point is shown by a chain double-dashed line.

The point where the ball hits the target screen can be detected by providing at least three vibration detectors (voice detectors) as in the principle of the epicenter detection. The approach shot training device uses four microphones (101 to 104) as voice detectors in order to correct the change in sound velocity.
The four microphones are installed at four corners of the frame 11, respectively, and detect a collision sound that is generated when the ball 17 hits the sheet 12 of the target screen and propagates in the air. Each microphone 101 to 104 is connected to the control unit 14, and the control unit 14 controls each microphone 1
The time when the collision sound signal detected by 01 to 104 is received is detected.

A microphone 105 is also installed at the hitting point where the mat 16 made of artificial grass is laid, and the club 1
The sound when the ball 9 hits the ball 17 is detected. This signal is also sent to the control unit 14 and the time is detected.

A display device 15 such as a CRT or LCD is connected to the control unit 14, and various analysis results (determination results, scores, instructions, etc., which will be described later) in the control unit 14 are displayed on the screen of the display unit 15. It is displayed and the player is notified immediately after the ball is hit.

FIG. 2 shows various trajectories of the ball which change depending on the count and hitting method of the club 19 to be used. As can be seen from this figure, the flight distance of the ball is the height at which it hits the target screen. It is not uniquely determined only by it, but also changes depending on the launch angle and the hitting speed. Therefore, in the golf approach shot practice device of the present embodiment, the coordinates of the point where the ball hits on the target screen 12 and the target screen 12 from the time when the ball is hit.
Based on the time until you hit the ball 17
Calculates the trajectory until the ball hits the target screen 12, and based on that, the falling point of the ball 17, the falling velocity,
Calculate the fall angle, etc. Further, by setting the falling speed and the falling angle, the falling energy and the rolling resistance of the ball 17 at the time of falling, the ball 1 after falling
Calculate up to a rolling distance of 7. These calculation methods will be described in detail later.

The electrical construction of the control unit 14 is shown in FIG. Four microphones 101 to 10 which are collision sound detecting means
The signals from 4 first pass through filters and amplifiers 106 to 109 provided in each. By passing through the filter, components such as ambient noise are removed from the signals of the microphones 101 to 104, and a signal of only a predetermined collision sound is extracted. The signals that have passed through the filters and amplifiers 106 to 109 are divided into two, and one of these four signals is collected and sent to the arrival detection circuit 132, where the earliest collision sound is detected. This signal is sent to the data memory 133 via the data memory control circuit 134. The hitting sound signal from the microphone 105 at the hitting point is also similarly hit through the hitting detection circuit 14 via the filter, the amplifier 130 and the like.
1, the hitting sound is detected there and sent to the data memory control circuit 134. The signals from the four microphones 101 to 104 around the target screen 12 are also sent to the A / D converter 131, and based on the signal from the data memory control circuit 134, only for a certain time before and after the ball 17 arrives. The detection signals from the microphones 101 to 104 are A / D-converted separately to obtain the data memory 133.
Written in.

The data of each collision sound is read by the MPU circuit (including a microprocessor, ROM, RAM, oscillation circuit, decoder, etc.) 135, and the arrival time is accurately obtained from the waveform of the collision sound that is vibrating in a complicated manner. After the pre-processing is performed, various data to be described later such as the trajectory of the ball 17 are calculated and determined. The MPU circuit 135 sends the result (evaluation, score, etc.) after performing these calculations to the output circuit 136, and the output circuit 136 outputs the result from various output devices 138 such as a monitor, a printer, and a voice synthesizer. Notify the player. The control unit 14 is used for the player to switch various modes described later and to input data.
Various keys and a switch 139 are provided in the box, and these input commands are sent to the MPU circuit 135 via the input circuit 137.

Next, a method of calculating the collision position of the ball 17 on the target screen 12 by detecting the collision sound when the ball 17 hits the target screen 12, and a sound wave transmission medium (in this case, air). The calculation method for correcting the difference in the transmission speed due to the temperature in) will be described. To simplify the description, the target screen 1
In the case of 2, the size of one side is 1, and the air resistance when the ball 17 flies is ignored.

Detection of Ball Collision Position on Target Screen As shown in FIG.
The coordinates of the four corners of S1 (0,0) and S2 (0,
1), S3 (1,1), S4 (1,0), ball 17
The coordinates of the collision position of P are defined as P (X, Y). And the point P
To the four corners S1 to S4 are L1 to L4, respectively. As described above, the microphones 101 to 104 as the collision sound detecting means are installed at the four corners S1 to S4.
Here, for convenience of later calculation, the collision sound is changed from the points P to S.
Four microphones 101-104 placed at 1-S4
The time (shortest time, which cannot be measured directly) before reaching the microphone closest to the point P is set to t0, and the time (the collision sound reaches the first microphone). Time from when the collision sound reaches the four microphones 101 to 104.
1, t2, t3, t4 (hence t1, t2, t3, t4
At least one of them is 0).

From the above relationship, the following equations hold for L1 to L4. L1 ² = X ² + Y ² = C ² · (t 0 + t 1) ² (1) L ^{2 2} = X ² + (Y−1) ² = C ² · (t 0 + t ² ) ² … (2) L 3 ² = (X− ^{1) 2 + (Y-1} ) 2 = C 2 · (t0 + t3) 2 ... (3) L4 2 = (X-1) 2 + Y 2 = C 2 · (t0 + t4) 2 ... (4) in addition, C is It is the speed of sound. By subtracting the formula (4) from the formula (1), X becomes X = {C ² · (t 0 + t 1) ² −C ² · (t 0 + t 4) ² +1} / 2 (5), and from the formula (4), By subtracting (3), Y becomes Y = {C ² · (t 0 + t 1) ² −C ² · (t 0 + t ² ) ² +1} / 2 (6). Equations (5) and (6) are unknown C (sound velocity) and t
Since 0 is included, these values will be obtained below.

First, from the expressions (1) to (4), the relationship of (L1 ² + L3 ² ) − (L2 ² + L4 ² ) = 0 holds, so that C ² · {2 · t0 · (t1 −t2 + t3 −t4) + T1 ² −t2 ² + t3 ² −t4 ² } = 0 (7) Since C ² > 0, there is a relationship of 2 · t 0 · (t ¹ −t ² + t ³ −t ⁴ ) + t 1 ² −t ^{2 2} + t 3 ² −t 4 ² = 0 (8) between t 0 and t ⁴ . Hereinafter, in the formula (8), t1−t2 + t3−
Consider the case of t4 ≠ 0 and the case of t1−t2 + t3−t4 = 0 separately.

In the case of I t1 −t2 + t3 −t4 ≠ 0 In this case, from equation (8), t0 = − (t1 ² −t2 ² + t3 ² −t4 ² ) / {2 · (t1 −t2 + t3 −t4)} ... It becomes (9). Putting t0 + ti = Ti (i = 1, 2, 3, 4) and substituting the equations (5) and (6) into the equation (1), C ⁴ · {T1 ⁴ + T3 ⁴ -2 · T2 ² · (T1 ²⁻ T2 ² + T3 ² )} − 2 · C ² · (T1 ² + T3 ² ) + 2 = 0 (10) Here, when a = T1 ⁴ + T3 ⁴ −2 · T2 ² · (T1 ² −T2 ² + T3 ² ) b = − (T1 ² + T3 ² ), the equation (10) is a · (C ² ) ² +2. ^{· b · C 2 + 2 =} 0 ... called (101) represented by a quadratic equation.

Since C ² > 0 and Ti> 0, the solution C ² of the quadratic equation (101) is C ² = {-b- (b ² -2 · a) ^1/2 } / a. . ^{Thus, C 2 = [(T1 2} + T3 2) - {(T1 2 + T3 2) 2 - 2 · (T1 4 + T3 4 -2 · T2 2 · (T1 2 -T2 2 + T3 2))} 1/2] / {T1 ⁴ + T3 ⁴ −2 · T2 ² · (T1 ² −T2 ² + T3 ² )} (11)

Since Ti is proportional to the distance (Li) between P and Si, there is a relationship of T1 ² + T3 ² = T2 ² + T4 ² as in the case of the above formula (7). Using this, rearranging the equation (11), C ² = [-{4 · (T1 ² + T3 ² ) ² − (T1 ² −T3 ² ) ² } ^1/2 + T1 ² + T3 ² ] / {T1 ⁴ + T3 ^{4 -2 · T2 2 · T4 2} } ... (12) ( although, t1-t2 + t3-t4 ≠ 0) above, the coordinate X of the impact point of the ball 17 on the target screen 12, Y is the formula (9) Calculated t0 and formula
It can be obtained by substituting C ² obtained from (12) into equations (5) and (6).

II When t1−t2 + t3−t4 = 0 in Expression (8) In this case, (t1 = t2, t3 = t4) or (t1 = t4, t
The case of 2 = t3) is considered. These cases will be further classified.

II-1 t1 = t2, t3 = t4 and t1 ≠
In the case of t4, t2 ≠ t3 In this case, the point P exists on a straight line parallel to the X-axis passing through the center of the target screen 12 (however, the center of the target screen 12 is excluded). The formula holds. Y = 0.5 L1 ² = L2 ² = X ² + (0.5) ² = C ² · (t 0 + t 1) ² … (13) L 3 ² = L 4 ² = (X−1) ² + (0.5) ² = C ² · ( t0 + t4) ² (14) Currently, there are four unknowns: C (sound velocity), t0 (transmission time of collision sound to the corner Si closest to the hitting point P), X, Y (coordinates of the hitting point P). Therefore, it is impossible to obtain these four unknowns from the above equation (3). Therefore, C (speed of sound)
Is the value obtained when t1−t2 + t3−t4 ≠ 0, or
Use the standard sound velocity at 25 ° C (described in the science chronology, etc.). Then, from equations (13) and (14), X = ± {4 · C ² · (t 0 + t 1) ² −1} ^1/2 / 2 (15) Since X ≧ 0 and a real number, the true solution among them is only X = + {4 · C ² · (t 0 + t 1) ² −1} ^1/2 / 2. Substituting this into equation (13) and rearranging it gives: 4 · C · t0 ² · {C ² · (t 1 −t 4) ² −1} + 4 · C ² · t 0 ·
(T1 + t4) · {C 2 · (t1-t4) 2 -1} + {C 2 · (t
^{1-t4) 2 -1} 2} +4 · {C 2 · (t1-t4) 2 -1} C 2 ·
t1 · t4 + 1 = 0. If {-C ² · (t 1 −t 4) ² +1} = A is set in the above equation and solved for t 0, t 0 = {− (t 1 + t 4) + (A−1) ^1/2 / (C ² · A)
^1/2 } / 2 is obtained. By substituting this into equation (15), t1
-T4> When 0, X = {(1- A 2) 1/2 + A 1/2} / (2 · A 1/2) , and the time of t1-t4 <0, X = {(1-A ² ) ^1/2 −A ^1/2 } / (2 · A ^1/2 ). As described above, Y = 0.5.

II-2 t1 = t4, t3 = t2 and t1 ≠
In the case of t3, t2 ≠ t4 In this case, the hitting point P exists on a straight line passing through the center of the target screen and parallel to the Y axis (however, excluding the center of the target screen). As in II-1, C
By treating (sound velocity) as a known number, t0 and Y are obtained as follows. By setting C ² · (t 1 −t ² ) ² −1 = A, t 0 = {− (t 1 + t 2) + (A−1) ^1/2 / (C ² · A)
When ^{1/2} / 2 t1-t2>} 0, when ^{Y = {(1-A 2} ) 1/2 + A 1/2} / (2 · A 1/2) t1-t2 <0, Y = the ^{{(1-a 2) 1/2} -A 1/2} / (2 · a 1/2). As described above, X = 0.5.

II-3 When t1 = t2 = t3 = t4 This means that the collision point P is the center of the target screen 12, and X = 0.5 Y = 0.5. From the above, in all cases, the coordinates P of the collision position of the ball 17 on the target screen 12
That is, (X, Y) is required. This coordinate value P
By comparing (X, Y) with a concentric target position drawn on the target screen 12 in advance, it is possible to determine which position (center or center) of the ball 17 the target has. ) Can be determined, and score calculation can be performed. These calculations are performed by the MPU circuit 13
5 does.

Next, at the time T0 when the ball 17 hits the target screen 12, the four microphones 10 are
Assuming that the time at which any one of 1 to 104 first detects the collision sound is T00, T0 = T00-t0. However, if t1 = t2 = t3 = t4, then t0
The value obtained in the case of t1-t2 + t3-t4 ≠ 0 as acoustic velocity C, or by using a sound velocity value at 25 ° C., and ^{T0 = T00-2 1/2 / (2 ·} C).

Calculation of trajectory of hit ball The variables used in the following calculations are defined as follows. θ: Ball launch angle Tf: Time from ball hit to target screen L0: Distance from hit point to target screen X: Ball collision point P (X, on target screen
Y) horizontal coordinate value Y: ball collision point P (X,
Y) vertical coordinate value V0: Ball launch speed (initial velocity) T0: Time when the ball hits the target screen (0 when hit) Ls: From hitting point to microphone for hitting time detection Distance Hg: Height difference between hitting point and falling target point Ts: Hitting sound detection time (when hitting is 0) g: Gravity acceleration In the above, the distance L0 from the hitting point to the target screen is It may be measured when the target screen 12 and the hitting point mat 16 are installed, but a standard distance is determined in advance (for example, a standard position is determined at an interval of about 50 cm between about 2 to 4 m). Every other), the player selects a desired distance from the selected distances and hits the hit point mat 1
It is preferable to install 6 and specify the selected distance with one touch using buttons or keys. It should be noted that a distance sensor is provided at the hitting point so that the target screen 12
It is also possible to measure the distance to and automatically send the distance data to the control unit.

From the equation of motion, the position of the ball at time t in the x direction (the flight direction of the ball) and the y direction (height direction) is as follows. x = The (V0 · cosθ) · t ... (16) y = (V0 · sinθ) · t-g · t 2/2 ... (17), x -direction at time t, the speed in the y-direction, as follows become. Vx = V0 · cos θ (18) Vy = V0 · sin θ−g · t (19)

First, from the time ts when the hitting sound of the ball 17 reaches the microphone 105 at the hitting point, the distance Ls from the hitting position to the microphone 105, and the time T0 when the ball 17 hits the target screen 12, the ball 17 is hit. The flight time Tf of is calculated as follows. Tf = T0-Ts + Ls / C Since the speed of the ball 17 is much slower than the speed of sound, a change in the speed of sound (about 0.6 m / sec / ° C.) with temperature is ignored.

Next, the ball 17 struck at the launch angle θ and the initial velocity V0 arrives at the target screen 12 which is separated from the hit point by the horizontal distance L0 after the flight time Tf, so that the following formula is established. L0 = V0 · Tf · cos θ (20) The same applies to the vertical direction. Y = (V0 · sinθ) · Tf-g · Tf 2/2 ... (21)

From the equations (20) and (21), the launch angle θ is obtained as follows. θ = atan {(1/2) · (2 · Y + g · Tf ² ) / L0} (22) Also, by substituting equation (22) into equation (20), the initial velocity V0
The V0 = (1/2) · {4 · L0 2 +4 · Y 2 + 4 · Y · g · Tf 2 + g 2 · Tf 4} 1/2 / Tf ... (23), time of flight of the ball 17 Tf And Y (this is the height of the collision point P on the target screen 12 obtained previously).

Next, by substituting the equations (22) and (23) into the equation of motion relating to the vertical position and finding the flight height H of the ball 17, H = (T / 2) .multidot. (2.multidot.Y- g · Tf ² −g · T · Tf) / Tf. When the ball 17 falls on the green whose height difference from the hitting point is Hg, the flight time Ta can be calculated as follows by setting H = Hg. Ta = {2 · Y + g · T0 2 + (4 · Y 2 +4 · Y · g · T0 2 + g 2 · T0 4 - 8 · g · Hg · T0 2) 1/2} / (2 · g · T0) …(twenty four)

Ta obtained in this way and equation (22),
By substituting (23) into the equation of motion (16) in the horizontal direction, the flight distance Lf of the ball 17 can be calculated as Lf = V0 · Ta · cosθ (25).

Next, in order to obtain the highest reaching altitude Ym,
When the time Tm when the vertical velocity Vy becomes 0 is calculated, it becomes Vy = V0.sin.theta.-g.tV0.sin.theta.-Tm = 0 Tm = (V0.sin.theta) / g, which is substituted into the equation (21). As a result, Ym = (V0 ² · sin ² θ) / (2 · g). From the above, all the flight trajectories of the ball 17 after being hit can be calculated. After calculating these trajectories, the MPU circuit 135 displays the trajectories on the display 15 or the like via the output circuit 136 in the manner shown in FIG. At this time, of course, the position of the target screen 12 is displayed, and the virtual trajectory after that in the case where the target screen 12 is not provided is also displayed.

Calculation of Movement of Ball After Landing When the ball 17 actually lands on the green, it bounces several times and then rolls on the grass and stops. At this time, the amount of backspin given to the ball 17 changes depending on the type of club, the type of ball, how to hit the ball, and the state of the green subtly changes depending on the falling location, so the bounce and rolling distances can be accurately measured. It is impossible to calculate However, it is possible to actually approximate the movement of the ball after the fall by performing calculations using the fall velocity, the fall angle, the sphere coefficient, the hardness of the green, the rolling resistance of the green, and the like. Hereinafter, an example of calculation for simulating the movement of the ball after the drop will be described. First, the drop angle θf and the horizontal speed Vx at the time of landing are obtained. The angle θt indicating the moving direction of the ball 17 can be expressed as follows from the vertical component Vy and the horizontal component Vx of the velocity. tan θt = Vy / Vx. In this formula, the time T until the ball 17 lands
Substituting a and the velocity Vx in the X direction (Vx is always equal to the initial velocity V0 because the influence of air resistance is ignored now),
The falling angle θf at the time of landing is tan θf = {V0 · sin θ−g · Ta} / (V0 · cos θ) θf = atan {tan θ−g · Ta / (V0 · cos θ)}.

When the ball 17 lands on the green at the time of landing, part of its kinetic energy is absorbed,
The degree of absorption depends on the green “catasa” and the falling angle θ.
It changes with f etc. Therefore, the “catalyst” of green is represented by the energy absorption coefficient A. Also, in fact,
When the ball 17 lands on the green, it bounces several times and then rolls on the grass to stop, but with this device, it will start rolling motion immediately after landing, and first, the horizontal direction at the start of rolling. The velocity Vg of is approximated by the following formula. Vg = V0 ・ cos θ ・ (cos ² θf + A ・ sin ² θf) ^1/2 (26)

Next, the rolling resistance R and the equation (25) are substituted into the equation of motion of an object which receives a constant negative acceleration, and the time Tr until the rolling speed Vr becomes 0 (stop) is obtained. Vr = Vg−R · Tr = 0 Tr = Vg / R Further, by substituting R and equations (25) and (26) into the equation of motion representing the moving distance of an object subjected to a negative constant acceleration, the ball rolls. distance Lr can be calculated as Lr = Vg · Tr-R · Tr 2/2.

The above calculation is performed on the target screen 12
The origin (lower left corner S1) was assumed to be at the same height as the hitting point, but when actually using this device, it is easier to use the target screen 12 slightly higher than the hitting point. . FIG. 5 is a side view showing a case where a height difference is provided between the hitting point and the target screen 12 as described above.
Shown in. In this case, the height information used for the calculation is, as shown in FIG. 5, the height Y0 at which the target screen 12 is lifted at the position Y in the height direction of the point where the ball 17 hits.
Must be used.

Further, the above equations assume the case where the ball 17 flies in the vertical plane including the hitting point and the center of the target screen 12, and when the flight trajectory of the ball 17 deviates to the left and right, the hitting ball is hit. Target screen 12 from the point
The horizontal distance L01 to the collision point P is L01 = {L0 ² + (X-0.5) ² } ^1/2 , and it is necessary to modify the calculation formulas so far in order to accurately calculate the flight distance of the ball 17. There is.

However, when displaying the hitting result as a golf approach shot practice device, a line parallel to the center line 61 of the target screen 12 is used rather than expressing the flight distance by the straight line distance connecting the hitting point and the falling point. Using a coordinate system with orthogonal lines, it is better to express how far the flight distance is and how much the deviation is to the left by how many meters before the target,
It is easier for the practitioner to understand how to express the distance to the right. Therefore, in this device, the flight distance is represented by Lf, the rolling distance is represented by Lr, and the distance to the position where the ball 17 stops is represented by Lf + Lr.

Next, since the deviation Xf on the left and right with respect to the center line of the ball drop position has a relationship of Lf / L0 = Xf / (X-0.5) from FIG. 6, Xf = {Lf. (X-0.5) } / L0. Similarly, the displacement Xa of the position where the flying ball 17 stops after rolling after falling is Xa = {(Lf + Lr). (X-0.5)} / L0. Note that Xa means a shift to the right when positive, and a shift to the left when negative.

In order to improve golf, it is said that it is necessary to continue practicing the swing of the club every day, although it may take a short time. However, if daily practice is monotonous, the player will get bored and will not last long. As described above, when the present shot practice device is used as a golf approach shot practice device, the above various calculations are performed from the data collected from one hit, and the results are displayed in various modes (for example, for a ball The trajectory is displayed on the display 15 as shown in FIG. 2, 5 or 6, and the collision point on the target sheet 12 is displayed as a target position on the target screen as shown in FIG. Compare and display scores to show scores, etc.), so you will not get tired of practicing every day. And the ball 17
Since the club 19 and the actual club 19 are used, it is possible to practice in a state extremely close to the actual approach shot. Further, the ball hit is naturally returned to the player, so that a large number of shots can be continuously made without having to collect the ball 17 each time, and the player can practice efficiently.

A golf approach shot practice device, which is another embodiment of the present invention (hereinafter referred to as "embodiment 2"), will be described. The entire golf approach shot practice device of this embodiment has the same configuration as that of the above-described first embodiment shown in FIG. 1, and the electrical configuration of the control unit 14 also corresponds to that of the first embodiment shown in FIG. The configuration is almost the same (the electric configuration of the control unit 14 may be slightly different depending on the method of calculating the collision position, as described later). In the present embodiment, by detecting the collision sound when the ball 17 hits the target screen 12, the target screen 1 of the ball 17 is detected.
The method of calculating the collision position on 2 is different from that of the first embodiment. The method of calculating the collision position in this embodiment will be described below with reference to FIGS. For simplification of explanation, it is assumed that the microphones 101 to 104 are located at the four corners of the target screen, and the ball 17
Ignore the air resistance when moving.

Detection of Ball Collision Position on Target Screen As shown in FIG. 13, a rectangular target screen 1
The coordinates of the four corners of 2 are S1 (0,0) and S2 (0, M), respectively.
y), S3 (Mx, My), S4 (Mx, 0), ball 1
The coordinates of the collision position of 7 are P (X, Y). The distances from the point P to the four corners S1 to S4 are L1 to L4, respectively. Similar to the first embodiment, microphones 101 to 104 as collision sound detecting means are installed at the four corners S1 to S4 (see FIG. 1). This device measures the time when the collision sound reaches each microphone. The times when the collision sound reaches each microphone are ta1, ta2, ta3, and ta4.

In order to specify the collision point, 3 from the collision point
You just need to know the distance to one or more microphones. Here, a case will be described in which three microphones, a microphone 102 and a microphone 104 that sandwich the microphone 101 are used, as a reference.

The time required for the ball 17 to collide with the target screen 12 and the collision sound generated by the collision to reach the microphone 101 (hereinafter referred to as "collision sound arrival time") is t0 (this is directly measured). Impossible), microphone 101 and microphone 102
The difference in the arrival time of the collision sound with t2, the microphone 101
Of the arrival time of the collision sound between the microphone and the microphone 104 is t4
Then, t2 = ta2-ta1 (27) and t4 = ta4-ta1 (28).

The speed of sound is required to convert the above times t0, t2, and t4 into coordinate axes on the target screen 12, that is, distances. The speed of sound C changes with the temperature T and is obtained by the following equation. C = 331.5 + 0.6 · T (29) Details of the speed of sound will be described later.

The distance L0 (= L1) from the position (collision point) P where the ball 17 collides with the target screen 12 to the microphone 101, the difference Lt2 between L0 and L2, L0 and L4.
By using the sound velocity C, the difference Lt4 is expressed as L0 = t0 · C (30) Lt2 = t2 · C (31) Lt4 = t4 · C (32).

The relationship between the collision point P (X, Y) in FIG. 13 and the above equations (30), (31) and (32) is as follows. X ² + Y ² = L 0 ² (33) (Mx-X) ² + Y ² = (L 0 + Lt 4) ² (34) X ² + (My-Y) ² = (L 0 + Lt ² ) ² (35) The above three formulas Therefore, X, Y, and L0 can be calculated as follows. ^{X = (Mx 2 -2 · L0} · Lt4 + Lt4 2) / (2 · Mx) ... (36) Y = (My 2 -2 · L0 · Lt2 + Lt2 2) / (2 · My) ... (37) L0 = [{ B4 ・ B2 ・ (B2 + B4 + 2 ・ Lt2 ・ Lt4)} ¹ / 2- (B4 ・ Lt4 ・ My ² + B2 ・ Lt2 ・ Mx ² )] / {2 ・ (B2 ・ Mx ² + B4 ・ My ² −Mx ・ My)} ... (38) or L0 = [- {B4 · B2 · (B2 + B4 + 2 · Lt2 · Lt4)} 1/2 - (B4 · Lt4 · My 2 + B2 · Lt2 · Mx 2)] / {2 · (B2 · Mx 2 ^{+ B4 · My 2 -Mx · My} )} ... (39) ^{However, B2 = My 2 -Lt2 2 B4} = Mx 2 -Lt4 2 L0 is with two solutions, the collision point P S1, S2, S3, S
If it is inside the rectangle with 4 as its apex, equation (38) is the distance between the collision points P and S1. For all other cases,
More on this later.

Method for Improving Accuracy and Reliability There are three measurement values (impact sound arrival times) ta1, ta2, ta4 used in the above calculation method. Here, by using another measured value ta3, the collision point P (X, Y)
There are four ways to obtain four solutions for.
By obtaining the average value of these four solutions, the error can be reduced and the accuracy can be improved. Further, the reliability can be improved by comparing the four solutions and performing an abnormal process to determine that the difference is within a set value and is normal, and if the difference is equal to or larger than the set value, there is some measurement error.

Measurement of Sound Speed C As described above, in order to calculate the collision position of the ball 17, the value of the transmission speed (sound speed) of the generated collision sound in the air is required. When high accuracy is not required or when the temperature is constant, the collision speed can be calculated using a preset sound velocity. When the temperature changes greatly or when high accuracy is required, it is necessary to measure the speed of sound or the temperature. Hereinafter, a method of using a temperature sensor such as a thermistor and a method of analyzing data obtained from four or more microphones will be described as methods for obtaining the sound velocity.

[1] Method Using Temperature Sensor such as Thermistor In this method, for example, a temperature detection circuit as shown in FIG. 12 is added to the electrical configuration of the control unit 14 shown in FIG. To measure. In this case, the output signal of the thermistor 152 which detects the temperature is input to the A / D converter 156 after being amplified by the amplifier 154. A /
The value of the signal input to the D converter 156 is converted into a digital signal and taken into the MPU circuit 135. As a result, the MPU circuit 135 obtains the temperature T and calculates the sound velocity C by C = 331.5 + 0.6 · T [m / sec]. Although FIG. 12 shows an example in which the detection signal of the temperature T is A / D converted and input to the MPU circuit, in addition to this, voltage / frequency conversion or voltage / pulse width conversion is performed and the MPU circuit remains as an analog signal. For example,
Many methods are possible. When the analog signal is input to the MPU circuit as it is, the digital value of the temperature T can be obtained by monitoring the input signal with a program and measuring the frequency and the pulse width, for example.

[2] Method of Analyzing Data Obtained from Four or More Microphones Provided Considering a case where microphones are provided at four corners S1 to S4 as shown in FIG. 13, in this case, the coordinates P ( X,
Y) and the coordinates S1 of the four corners with the microphone
(0,0), S2 (0, My), S3 (Mx, My), S4
The following equation holds between (Mx, 0). L1 ² = X ² + Y ² (40) L2 ² = X ² + (Y-My) ² (41) L3 ² = (X-Mx) ² + (Y-My) ² ... (42) L4 ² = (X-Mx) ² + Y ² (43) where Li: distance from collision point to each microphone (i = 1
4) When these are expressed by the speed of sound and time, L1 ² = C ² · (t0 + t1) ² (44) L2 ² = C ² · (t0 + t2) ² (45) L3 ² = C ² · ( t0 + t3) ² (46) L4 ² = C ² · (t0 + t4) ² (47) However, t0: Time from collision sound generation to collision sound arrival at the reference microphone (collision sound arrival time) ti: Reference microphone Difference between the detection time of the collision sound by and the detection time of the collision sound by each microphone From equations (40) to (47), 2 · t0 · (t1 − t2 + t3 − t4) + t1 ² − t2 ² + t3 ² − t4 ² = 0 t0 = − (t1 ² −t2 ² + t3 ² −t4 ² ) / {2 · (t1 −t2 + t3 −t4)} (48) To simplify the equation, T1 = t0 + t1 T2 = t0 + t2 T3 = t0 + t3 T4 = T0 + t4 From equation (40) ~ (47), {(T4 2 -1T1 2) · Mx 2 - (T2 2 -T1 2) · My 2} · C 4 -2 · My 2 · Mx 2 · (T4 2 + T2 2 ) and a ^{· C 2 + Mx 2 · My} 2 · (Mx 2 + My 2) = 0 ... (49). Here, a = (T4 ² −T1 ² ) · Mx ² − (T2 ² −T1 ² ) · My ² b = My ² · Mx ² · (T4 ² + T2 ² ) c = Mx ² · My ² · (Mx ² + My ²⁾ and put the ^{a · (C 2) 2 -2} · b · (C 2) + c = 0 ... (50) represented by the quadratic equation mentioned. C ^2> 0, Ti> 0 than ^{C 2 = {b- (b 2} -a · c) 1/2} / a C> 0 from ^{C = [{b- (b 2} -a · c) 1/2 } / A] ^{1/2 The} sound velocity C may not be calculated depending on the arrangement of the microphones and the collision position of the ball. For example, ta1 =
When any one of the conditions ta2, ta1 = ta4, ta3 = ta2, ta3 = ta4 is satisfied, the denominator of the formula (48) 2.
(t1-t2 + t3-t4) becomes 0 and cannot be calculated. In such a case, the fact that the temperature does not fluctuate abruptly is used to substitute the sound velocity C or the like obtained immediately before.
On the other hand, the above-mentioned method using the temperature sensor is advantageous over the present method in this point because the sound velocity C can be obtained regardless of the collision position.

The sound velocity C is calculated as described above, and the expression (3
1), (32), (38) and (39) are used to obtain Lt2, Lt4 and L0, and these are substituted into equations (36) and (37), so that the position of the collision point P is also determined in this embodiment. (X, Y) can be calculated. After calculating the collision position (X, Y), the trajectory of the hit ball and the movement of the ball after landing can be calculated in the same manner as in the first embodiment.

Up to now, the description has been made assuming that the microphones are arranged at the four corners of the target sheet 12 as shown in FIG. 13 and the collision point P is inside the rectangle having the apexes thereof. It is also possible to calculate when there is a collision point P outside the microphone as shown in FIG. Here, a case where the range of the collision point P is expanded to the outside of the rectangle formed by each microphone will be described. In the calculations so far, L0 is given by equations (38) and (39)
Have one solution. In the plain area of FIG. 14, the equation (38) that gives one solution of L0 represents the collision point P.
In the shaded area of, the equation (39) giving another solution of L0 represents the collision point P. As described above, in the calculation for detecting the collision position already described, two values are obtained as L0, and the collision point P is not uniquely determined. Further, the microphone data (collision sound detection time) necessary for the calculation for detecting the collision position is ta1, ta2, ta3, ta.
Since there are three out of four, there are four combinations of microphone data to be used. Therefore, if the calculation for detecting the collision position described above is performed by four methods,
A total of 8 solutions can be obtained. These eight solutions are
It always includes four or more L0 indicating the collision point P. Therefore, 8
If there are four or more similar values in one solution, it means L0 indicating the collision point P. As described above, by using four microphones, the position of the collision point P can be detected on any plane on which the microphone is located. Furthermore, by installing five or more microphones, it is possible to apply to not only a plane but also three-dimensional spatial coordinates.

Using a method of detecting a position in a three-dimensional space with five or more microphones,
As shown in FIG. 1, it is possible to detect the hit position and time of the ball without installing the microphone 105 at the hit point. So according to this method,
The ball can be hit from an arbitrary position instead of a specific position, and the movement of the ball can be simulated. In this case, the microphone for detecting the collision position may be shared, but a microphone for detecting the launch position may be separately provided.

Further, since the range of time from when the ball is hit to when it reaches the target can be roughly predicted, FIG.
Of the A / D converter 13 within a predetermined time after the signal reaches the data memory control circuit 134 of the ball hit detection circuit 141.
It is advisable not to write signals other than the signal output from 1 into the data memory 133. As a result, malfunctions due to external noise can be significantly reduced.

The calculation methods in the first and second embodiments described above are merely examples, and various calculation methods can be used in addition to them. For example, the microphone can be attached not only at the four corners of the target screen as shown in FIG. 1, but also at the arbitrary positions in consideration of the diamond-shaped position and the space around the practice device. In this case, the formula for detecting the collision point P (X, Y) of the ball changes depending on the arrangement of the microphones. However, even in this case, it is only necessary to change the X and Y calculation formulas, and the trajectory calculation after the collision point P (X, Y) is calculated can be performed as it is.

Further, in the calculations in the above-mentioned first and second embodiments, the air resistance of the ball 17 during flight is neglected, but in the case of the approach shot, the distance over which the ball 17 flies is relatively short, and the ball 17 is relatively short. Since the flight speed of the ball is not so large and the mass of the ball 17 is also sufficiently large, the air resistance during flight can be ignored in this way. Similarly, the change in flight motion due to the spin of the ball 17 and the braking effect after landing are also excluded from the calculation. Further, the ball 17 that has fallen on the lawn absorbs part of its kinetic energy by the lawn, the bound height gradually decreases, and finally the ball 17 rolls. When rolling, the lawn's rolling resistance absorbs kinetic energy and eventually stops.
These spin effect, energy absorption at the time of bouncing, rolling resistance, etc. differ depending on the conditions of the ball 17 and the lawn,
By measuring the flight distance of the ball 17 shot under typical conditions in advance and the rolling distance after the first landing, etc., and defining representative values (typical values) of various parameters, Can be considered. Alternatively, by allowing the player to arbitrarily change the representative value, it becomes possible to perform the trajectory calculation corresponding to various conditions.

In consideration of using the training device indoors, it is preferable that the frame 11 is an assembling type by a pipe, and for safety, a net (a net between the target screen and the hitting point) is provided. Of course, it is necessary to have a smaller eye than the ball), and it is desirable to set a metal fitting for fixing the net and the frame 11 as a set.

[0072]

Since the object collision position detection device of the present invention can detect the position where a flying object such as a ball collides with a predetermined target or the like, it is not limited to golf practice but shot practice in various competitions. It can also be used for throwing practice and play. For example, it can be used for batting and pitching practice of baseball, tennis practice, American football throwing practice, play gun shooting practice, and the like. Further, instead of preparing a special target screen as the target as in the above embodiment, it is possible to mount, for example, three or more vibration detectors (microphones or the like) on an existing wall. If a means for detecting the ejection time of a flying object such as a ball is provided, not only the collision position but also the trajectory of the flying object can be calculated including the virtual trajectory after the collision, so golf shot practice is possible. You can practice batting practice for baseball, tennis practice, etc. more effectively. By adding various parameter inputs and data processing based on the basic functions of the present invention, it is possible to practice and play in various modes and expand the range of application.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a golf approach shot practice device which is an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between various trajectory of a ball by a shot and a collision position and an angle with a target screen.

FIG. 3 is a block diagram showing the electrical configuration of the golf approach shot practice device of the embodiment.

FIG. 4 is an explanatory view showing a positional relationship (in the case of the first embodiment) between a collision area of a ball on a target screen and a microphone provided around the collision area.

FIG. 5 is an explanatory diagram of a trajectory when there is a difference in height between the shot position and the green position.

FIG. 6 is an explanatory diagram of a trajectory when the ball is shifted to the left and right and shot.

FIG. 7 is a configuration diagram showing an outline of a golf approach shot practice device in which a ball focusing frame is provided between a target screen and a hitting point.

FIG. 8 is a front view (a) and a side view (b) of a target screen sheet of the golf approach shot practice device of the embodiment.

FIG. 9 is a front view (a) and a side view (b) of a state in which a target screen sheet is mounted on a frame.

10 is a cross-sectional view taken along the lines A and B in FIG.

FIG. 11 is a cross-sectional view taken along the line C in FIG.

FIG. 12 is a diagram showing a temperature detection circuit used when a sound velocity is obtained using a temperature sensor.

FIG. 13 is an explanatory diagram showing a positional relationship (in the case of a second embodiment) between a ball collision area on a target screen and a microphone provided around the collision area.

FIG. 14 is a diagram showing a positional relationship between a collision point and a microphone when a collision point exists outside a rectangle having four corners where the microphone is arranged as vertices.

[Explanation of symbols]

11 ... Frame 12 ... Seat (target screen) 13 ... Seat lower end 14 ... Control unit 15 ... Display device 16 ... Hitting point mat 17 ... Ball 18 ... Ball track 19 ... Club 101, 102, 103, 104, 105 ... Microphone

Claims (8)

[Claims] 1. A collision sound detecting means placed on at least three places which are not collinear around the detection area, and b) based on the time when the collision sound is detected by each collision sound detecting means, within the detection area. An object collision position detection device, comprising: an arithmetic unit that calculates an object collision position. 2. Further, d) an emission time detection means for detecting the time when the colliding object is emitted from a predetermined point, and e) a time when the collision sound is detected by each collision sound detection means and an emission time detection means. Based on the ejection time detected by, the moving time from the point of ejection of the object at the point of ejection to the point of collision of the object is calculated, and further the collision time is calculated from the moving time and the object collision position calculated by the calculating means. 2. The object collision position detection device according to claim 1, further comprising: second calculation means for calculating the trajectory of the object and the virtual trajectory after the collision. 3. A target screen composed of a) a sheet stretched around a frame, b) at least three collision sound detecting means arranged around the target screen, and c) collision by each collision sound detecting means. A shot practicing apparatus comprising: a calculation unit that calculates a collision position of a projectile on a target screen based on a time when a sound is detected. 4. Further, d) an injection time detection means for detecting the injection time of the flying object at the injection point provided in front of the target screen, and e) a detection signal from each collision sound detection means and the injection time detection means. In response to this, the flight time from the ejection time of the flying object at the ejection point to the collision time of the flying object with the target screen is calculated, and further, the flight time and the collision position calculated by the calculating means collide with the target screen. 4. The shot practice apparatus according to claim 3, further comprising a second calculation means for calculating the trajectory of the flying object and the virtual trajectory after the collision. 5. The collision position of the flying object on the target screen, which is the result calculated by the calculation means or the second calculation means,
The shot practice device according to claim 4, further comprising display means for displaying the trajectory of the flying object. 6. A collision target point and a score area of a flying object are drawn on a sheet of a target screen.
The shot practice device according to any one of 5 above. 7. The shot practice apparatus according to claim 3, wherein the flying object is a golf ball, and the ejection time detecting means is a hitting sound detector for detecting hitting sound of the golf ball by the club. 8. The sheet of the target screen is extended from the bottom of the frame to the hitting point side, whereby the ball after hitting the sheet returns to the hitting point side. The described shot practice device.