JP7468897B2 - Target systems and programs - Google Patents

Description

The present disclosure relates to a targeting system and a program, and in particular to a targeting system and a program that enable the position at which an object fired at a target strikes the target to be identified with high accuracy and high speed.

Conventionally, shooting competitions have been held using soft air guns, which are toy guns equipped with a mechanism for firing plastic bullets (hereafter referred to as BBs (Ball Bullets)) using low-pressure compressed air or the like. For example, in shooting competitions, competitors compete for scores based on the position at which a BB bullet hits a target. Therefore, in shooting competitions, it is very important to accurately detect the position at which the BB bullet hits.

Therefore, the applicant of the present application has proposed a targeting system that can accurately calculate the impact position, impact speed, energy, etc. of a BB bullet by detecting the shock waves generated when the BB bullet hits the target board (see, for example, Patent Document 1).

JP 2014-25677 A

However, in the target system proposed in the above-mentioned Patent Document 1, before detecting the impact position of the BB bullet, it was necessary to prepare in advance, for example, array data in which detection time difference data is arranged at a predetermined interval. Therefore, it is believed that convenience can be improved if the impact position can be identified with high accuracy and high speed without preparing such array data in advance.

This disclosure was made in light of these circumstances, and makes it possible to quickly and accurately identify the position where an object hits a target.

The target system according to one aspect of the present disclosure includes a detected impact position calculation unit that calculates the position where an object hits a target board as a detected impact position based on an acoustic signal that detects an impact sound generated when the object hits the target board, a virtual impact position calculation unit that calculates virtual impact positions that are virtual impact positions that are obtained if the object hits a specified position on the target board and calculates a predetermined number of the virtual impact positions corresponding to the predetermined number of the specified positions, and a specific target area limiting unit that limits the size of a specific target area, which is an area that is identified as including the position where the object hits the target board, to an area that is a predetermined ratio narrower than the specific target area based on a comparison between the detected impact positions and the predetermined number of the virtual impact positions, and identifies the position where the object hit the target board by repeatedly performing a process of limiting the specific target area using the specific target area limiting unit and narrowing the specific target area.

A program according to one aspect of the present disclosure includes a step of calculating the position where an object hits a target board as a detected impact position based on an acoustic signal that detects an impact sound generated when the object hits the target board, calculating virtual impact positions that are virtual impact positions that are obtained if the object hits a specified position on the target board, calculating a predetermined number of the virtual impact positions corresponding to a predetermined number of the specified positions, and limiting the size of a specific target area, which is an area that is identified as including the position where the object hit the target board, to an area that is a predetermined ratio narrower than the specific target area based on a comparison between the detected impact positions and the predetermined number of the virtual impact positions, and causes a computer to execute a process of identifying the position where the object hit the target board by repeatedly performing the process of limiting the specific target area and narrowing the specific target area.

In one aspect of the present disclosure, the position where the object hits the target board is calculated as the detected impact position based on an acoustic signal that detects the impact sound generated when the object hits the target board, and virtual impact positions, which are virtual impact positions that are obtained if the object hits a specified position specified on the target board, are calculated, and a predetermined number of virtual impact positions corresponding to the predetermined number of specified positions are obtained. Then, based on a comparison between the detected impact positions and the predetermined number of virtual impact positions, the size of a specific target area, which is an area identified as including the position where the object hit the target board, is limited to a narrow area that is a predetermined ratio to the specific target area, and the process of limiting the specific target area is repeated to narrow the specific target area, thereby identifying the position where the object hit the target board.

According to one aspect of the present disclosure, the location where an object hits a target can be identified with high accuracy and speed.

The effects described here are not necessarily limited to those described herein, and may be any of the effects described in this disclosure.

1 is a perspective view showing a first configuration example of a target system to which the present technology is applied. FIG. 2 is a perspective view showing a configuration example of a target device. 13A and 13B are diagrams illustrating the basic concept of a landing position identification method for identifying a landing position by looping a process for limiting a target region to ¼ based on a comparison. FIG. 4 is a diagram showing a waveform output from an acoustic sensor. 11A and 11B are diagrams illustrating the relationship between the detection time difference and the distance from the impact position to the acoustic sensor. FIG. 13 is a diagram illustrating a virtual impact position that is set during the first loop. FIG. 13 is a diagram illustrating a process of limiting a target area to 1/4 based on a comparison during a first loop. FIG. 13 is a diagram illustrating a virtual impact position that is set during a second loop. FIG. 13 is a diagram illustrating a process of limiting the target area to 1/4 based on a comparison during the second loop. 2 is a block diagram showing an example of the configuration of an impact position identification processing device; 13 is a flowchart illustrating a landing position specifying process. 13 is a flowchart illustrating a virtual impact position coordinate calculation process. 13 is a flowchart illustrating an area limiting process. FIG. 11 is a perspective view showing a second configuration example of the target system. 1 is a block diagram showing an example of the configuration of an embodiment of a computer to which the present technology is applied.

Below, specific embodiments of the present technology will be described in detail with reference to the drawings.

<First Configuration Example of Target System>
As shown in FIG. 1, the target system 10 is composed of a target device 11, a display 12, and a PC (Personal Computer) 13, and the display 12 is disposed on the rear side of the target device 11.

For example, the user places PC 13 nearby, connects target device 11 and PC 13 with signal cable 14, and connects display 12 and PC 13 with video cable 15. Note that, for example, wireless communication may be used to connect target device 11 and display 12 to PC 13. Then, the user operates PC 13 to display target image 16, which represents the target when shooting, on the display unit of PC 13 and also outputs it externally to display it on display 12.

The user can then aim the barrel of the soft air gun 17 at the target device 11, look through the sights fixed along the barrel, and aim at the target image 16 displayed on the display 12 to perform target shooting. The BB bullets 18 fired from the soft air gun 17 fall onto a collection mat 19 placed below the front side of the target device 11, after which the momentum of the impact is absorbed by the bending of the target plate 23 (see FIG. 2) of the target device 11, and the BB bullets 18 are collected without scattering. Here, it is preferable to use a material such as boa fabric or pile fabric for the collection mat 19, which absorbs the impact of the falling BB bullets 18 and has low resilience (the property of slowly returning to its original shape) so that the BB bullets 18 do not bounce back.

The target system 10 can detect the impact position where the BB bullet 18 that flew toward the target device 11 hits the target board 23 (see FIG. 2). This allows the target system 10 to display an impact mark P indicating the detected impact position superimposed on the target image 16 displayed on the display 12, allowing the user to recognize the impact position of the BB bullet 18 without taking his eyes off the display 12. At the same time, the target system 10 can also display the impact mark P superimposed on the target image 16 displayed on the display unit of the PC 13, allowing the user to check the impact position of the BB bullet 18 in detail on the PC 13 at hand.

The target system 10 is configured in this way and can be used in competitions in which players compete to see who can hit the target with the most accurate shot, using the target image 16 displayed on the display 12 as a target.

An example of the configuration of the target device 11 will be described with reference to the oblique view of the target device 11 shown in Figure 2.

As shown in FIG. 2, the target device 11 is configured with fixing members 21 and 22, a target plate 23, a back plate 24, support members 25 and 26, acoustic sensors 27-1 to 27-4, a temperature sensor 28, and a control unit 29.

The fixing members 21 and 22 are, for example, members whose cross-section is U-shaped when the target device 11 is viewed from the side, and fix the target board 23 and the back plate 24 so that they maintain a constant distance from each other and have a flat shape. That is, the fixing member 21 is approximately the same length as the width of the target board 23 and the back plate 24, and fixes the upper edges of the target board 23 and the back plate 24. Similarly, the fixing member 22 is approximately the same length as the width of the target board 23 and the back plate 24, and fixes the lower edges of the target board 23 and the back plate 24.

The target board 23 is a transparent member that allows the target image displayed on the display 12 to pass through, and is made of a soft sheet-like member that can deflect and receive the impact of the BB bullets 18 fired at the target image by the soft air gun 17 in FIG. 1. For example, it is preferable to use a soft polyvinyl chloride resin with a thickness of 1.5 mm for the target board 23, as this is a material that has a slow recovery speed in response to deformation due to impact. In addition, the target board 23 is fixed at its upper edge to the side surface on the front side of the fixing member 21 and at its lower edge to the side surface on the front side of the fixing member 22 so that it is flat overall when stretched approximately vertically in front of the display 12, i.e., so that it does not deflect.

The back plate 24 is made of the same transparent, soft sheet-like material as the target plate 23, such as soft polyvinyl chloride resin with a thickness of 1.5 mm, and is placed on the back side of the target plate 23 (the display 12 side as seen by the user). That is, the back plate 24 is fixed to the side surface of the back side of the fixing member 21 in a planar manner similar to the target plate 23, with the upper edge fixed to the side surface of the back side of the fixing member 22.

In this manner, the target plate 23 is fixed to the front side of the fixing members 21 and 22, and the back plate 24 is fixed to the rear side of the fixing members 21 and 22. This provides a space 30 between the target plate 23 and the back plate 24, with a distance corresponding to the width of the upper surface of the fixing member 21 and the width of the lower surface of the fixing member 22. The space 30 is open on both the left and right sides, which has the effect of allowing the acoustic sensor 27 to stably acquire impact sounds, as described below.

Support members 25 and 26 are rod-shaped members (so-called cut bolts) with threads formed on the sides along their entire length, and are formed to be slightly longer than the vertical width of target plate 23 and back plate 24. In addition, when viewing target device 11 from the front, support member 25 supports the left end of fixing member 21 and the left end of fixing member 22, and support member 26 supports the right end of fixing member 21 and the right end of fixing member 22.

For example, two nuts (not shown) are screwed onto the upper screws of the support members 25 and 26 so as to sandwich the fixed member 21, and two nuts (not shown) are screwed onto the lower screws of the support members 25 and 26 so as to sandwich the fixed member 22. This supports both ends of the fixed members 21 and 22. Here, by adjusting the position of the nuts (not shown), the distance between the fixed members 21 and 22 can be adjusted to place the target plate 23 and the back plate 24 in a state in which a certain degree of tension is applied. In addition, by using a structure in which the fixed members 21 and 22 are supported by using nuts, the support members 25 and 26 can be easily removed, and for example, the target plate 23 and the back plate 24 can be rolled up around the fixed member 22 as an axis. In this way, by rolling up the target device 11 into a roll, portability and storability can be improved.

The acoustic sensors 27-1 to 27-4 acquire the impact sound generated when the BB bullet 18 (Figure 1) hits the target board 23, and supply the control unit 29 with an acoustic signal according to the change in amplitude of each acquired impact sound.

The acoustic sensors 27-1 to 27-4 are fixed in the space 30 between the target plate 23 and the rear plate 24 on the rear side of the target plate 23, near the four corners of the target plate 23, so as to be optimal positions for acquiring impact sounds. For example, the acoustic sensor 27-1 is disposed near the left end of the surface facing the downward side of the fixed member 21, and the acoustic sensor 27-2 is disposed near the right end of the surface facing the downward side of the fixed member 21. The acoustic sensor 27-3 is disposed near the left end of the surface facing the upward side of the fixed member 22, and the acoustic sensor 27-4 is disposed near the right end of the surface facing the upward side of the fixed member 22. Note that hereinafter, when there is no need to distinguish between the acoustic sensors 27-1 to 27-4, they will simply be referred to as acoustic sensors 27.

In this embodiment, a configuration using four acoustic sensors 27-1 to 27-4 will be described, but the number of acoustic sensors 27 is not limited to four. For example, three, six, eight, or any other number of acoustic sensors 27 that can appropriately measure the impact position, etc., can be used depending on the size or shape of the target device 11. For example, when six acoustic sensors 27 are used, acoustic sensors 27 are placed at the four corners as well as at the center of the top and bottom sides.

Here, the acoustic sensor 27 is placed in a closed space 30, the front side of which is closed by the target plate 23, the rear side of which is closed by the rear plate 24, and only the left and right sides of the target device 11 are open. For example, the space 30 is not a completely sealed space, but is configured with appropriate openings. In this way, the space 30 is configured to be partially open by the openings, so that it is not completely open, but is also different from a completely closed one in that it appropriately reverberates the impact sound while appropriately suppressing the increase in pressure. Therefore, in the target device 11, air can easily flow in and out of such a closed space 30 through the openings, and therefore, for example, the increase in pressure inside the space 30 caused by the impact of the BB bullet 18 on the target plate 23 is appropriately suppressed.

As a result, even if the volume of the space 30 suddenly decreases due to the target plate 23 bending when the BB bullet 18 hits, the air can be appropriately discharged through the opening, thereby appropriately suppressing the increase in pressure in the space 30 when the BB bullet 18 hits. This allows the acoustic sensor 27 to stably acquire impact sounds. Therefore, the target device 11 can improve the detection accuracy of the impact position and impact speed by suppressing the variation in the impact position and impact speed determined based on the acoustic signal output from the acoustic sensor 27.

The temperature sensor 28 detects the temperature in the closed space 30 in which the acoustic sensor 27 is placed, and supplies a temperature signal indicating that temperature to the control unit 29. For example, in the targeting system 10, the sound speed used to calculate the impact position of the BB bullet 18 is corrected based on the temperature detected by the temperature sensor 28.

The control unit 29 is attached to the center of the upper surface of the fixed member 21, and the signal cable 14 connected to the PC 13 in FIG. 1 is detachably connected to it. The control unit 29 is also connected to signal lines for inputting the acoustic signals output from the acoustic sensors 27-1 to 27-4, and signal lines for inputting the temperature signal output from the temperature sensor 28 (neither shown). The control unit 29 also contains a signal processing board that outputs a detection signal for detecting the impact position and impact speed of the BB bullet 18 when it hits the target board 23 by performing a predetermined signal processing on the acoustic signal output from the acoustic sensor 27 when the BB bullet 18 hits the target board 23.

In the predetermined signal processing by the signal processing board of the control unit 29, the acoustic signal is amplified and full-wave rectified, and a peak hold signal that holds the peak value of the amplitude, and an impact sound detection time signal that indicates the timing when the signal obtained by integrating the peak hold signal becomes equal to or exceeds a reference value are output as detection signals. This detection signal is supplied from the control unit 29 to the PC 13 in FIG. 1. Note that the signal processing by the signal processing board of the control unit 29 is described in detail in the above-mentioned Patent Document 1.

<How to identify the impact point>
A method for identifying the impact position of the BB bullet 18 in the targeting system 10 will be described with reference to FIGS.

First, the basic concept of the method for identifying the impact position of the target system 10 will be explained with reference to FIG.

The target system 10 can employ a method of identifying the impact position of the BB bullet 18 by repeatedly performing an area limiting process to limit the size of the specific target area, which is identified as the area that contains the target impact position, which is the final target impact position, to a smaller area (e.g., 1/4 of the area).

For example, in the area limiting process, it is determined which of the four areas obtained by dividing the specific target area vertically and horizontally contains the detected impact position DP, which is the impact position calculated from the acoustic signal detected by the acoustic sensor 27. This determination is made based on a comparison between the detected impact position DP and four virtual impact positions TP1 to TP4, which are virtual impact positions calculated assuming that the impact occurs at the four corners of the specific target area, as described below with reference to Figures 7 and 9.

Furthermore, in the impact position identification method of the target system 10, when the area limitation process is performed for the first time, i.e., when the loop count n, which indicates the number of times the area limitation process has been repeated, is 0, the size of the specific target area is set to a width and height that covers the entire surface of the target device 11. Specifically, as shown in FIG. 3, when the area limitation process is performed for the first time, the width W[0] of the specific target area is set to the initial value areaW (= 800 mm), and the height H[0] of the specific target area is set to the initial value areaH (= 440 mm).

When the size of the specific target area is limited to 1/4 each time the area limiting process is repeated, the width W[n] and height H[n] of the specific target area when the area limiting process of the nth loop is performed are set to 1/2 the initial value (areaW/ ²ⁿ and areaH/ ²ⁿ ).

That is, as shown in FIG. 3, when the area limitation process of the first loop is performed, the width W[1] of the specific target area is narrowed to 1/2 the initial value areaW (= 400), and the height H[1] of the specific target area is narrowed to 1/2 the initial value areaH (= 220). Similarly, when the area limitation process of the second loop is performed, the width W[2] of the specific target area is narrowed to 1/4 the initial value areaW (= 200), and the height H[2] of the specific target area is narrowed to 1/4 the initial value areaH (= 110). Similarly, each time the area limitation process is repeated, the width W[n] and height H[n] of the specific target area are narrowed based on the loop count n.

In addition, in the impact position identification method of the target system 10, the range of the specific target area when the area limiting process of the nth loop is performed is identified using the upper left end A1[n] of the specific target area, and the width W[n] and height H[n] of the specific target area. That is, as shown in FIG. 3, the range of the specific target area is identified by the coordinates (sumX[n], sumY[n]) indicating the upper left end A1[n], the coordinates (sumX[n]+W[n], sumY[n]) indicating the upper right end A2[n], the coordinates (sumX[n], sumY[n]+H[n]) indicating the lower left end A3[n], and the coordinates (sumX[n]+W[n], sumY[n]+H[n]) indicating the lower right end A4[n].

For example, when the area limitation process is performed for the first time (loop count n=0), the coordinates (sumX[0], sumY[0]) indicating the upper left end A1[0] of the specific target area are set to, for example, the device origin (0, 0), which is the upper left end of the target device 11. Therefore, the range of the specific target area in the area limitation process performed for the first time is specified by the coordinates (0, 0) indicating the upper left end A1[0], the coordinates (W[0], 0) indicating the upper right end A2[0], the coordinates (0, H[0]) indicating the lower left end A3[0], and the coordinates (W[0], H[0]) indicating the lower right end A4[0].

Then, as the area limiting process is repeated to limit the size of the specific target area to 1/4 of the original size, the coordinates (sumX[n], sumY[n]) indicating the upper left corner A1[n] of the specific target area are set to the coordinates indicating the upper left corner of the area in the previous specific target area where the specific target area was limited to 1/4 of the original size.

Therefore, if the specific target area is limited to the upper left 1/4 area in the area limiting process of the nth loop, the coordinates (sumX[n+1], sumY[n+1]) indicating the upper left end A1[n+1] of the specific target area used in the area limiting process of the n+1th loop are the coordinates (sumX[n], sumY[n]) of the upper left end of the upper left 1/4 area. Also, if the specific target area is limited to the upper right 1/4 area in the area limiting process of the nth loop, the coordinates (sumX[n+1], sumY[n+1]) indicating the upper left end A1[n+1] of the specific target area used in the area limiting process of the n+1th loop are the coordinates (sumX[n]+W[n]/2, sumY[n]) of the upper left end of the upper right 1/4 area.

Similarly, if the specific target area is limited to the lower left 1/4 area in the area limiting process of the nth loop, the coordinates (sumX[n+1], sumY[n+1]) indicating the upper left end A1[n+1] of the specific target area used in the area limiting process of the n+1th loop are the coordinates (sumX[n], sumY[n]+H[n]/2) of the upper left end of the lower left 1/4 area. Also, if the specific target area is limited to the lower right 1/4 area in the area limiting process of the n+1th loop, the coordinates (sumX[n+1], sumY[n+1]) indicating the upper left end A1[n+1] of the specific target area used in the area limiting process of the n+1th loop are the coordinates (sumX[n]+W[n]/2, sumY[n]+H[n]/2) of the upper left end of the lower right 1/4 area.

In this way, the coordinates (sumX[n+1], sumY[n+1]) indicating the upper left end A1[n+1] of the specific target area used in the area limitation process of the n+1th loop will differ depending on the area to which the specific target area is limited by the area limitation process of the nth loop. In other words, the coordinates (sumX[n+1], sumY[n+1]) indicating the upper left end A1[n+1] are appropriately added to W[n]/2, which is half the width W[n] of the specific target area, and H[n]/2, which is half the height H[n] of the specific target area, depending on the area to be limited, and are accumulated each time the area limitation process is repeated.

In the example shown in FIG. 3, in the first area limitation process, it is determined that the area including the detected impact position DP is the upper right quarter of the specific target area with width W[0] and height H[0]. Therefore, the coordinates (sumX[1], sumY[1]) indicating the upper left end A1[1] of the specific target area in the area limitation process of the first loop are the coordinates indicating the upper left end of the upper right quarter of the area of the previous specific target area. In other words, the X-axis value sumX[1] of the coordinate indicating the upper left end A1[1] of the specific target area in the area limitation process of the first loop is the sumX[0] of the X-axis value of the coordinate indicating the upper left end A1[0] of the previous specific target area plus W[0]/2, which is half the width W[0] of the previous specific target area.

Here, since the X-coordinate value sumX[0] of the coordinate indicating the upper left corner A1[0] of the specific target area in the first area limitation process was 0, the X-coordinate value of the coordinate indicating the upper left corner A1[1] of the specific target area in the area limitation process of the first loop is W[0]/2. In addition, the Y-coordinate value sumY[1] of the coordinate indicating the upper left corner A1[1] of the specific target area is simply sumY[0] (=0). Therefore, the range of the specific target area in the area limitation process of the first loop is specified by the coordinate indicating the upper left corner A1[1] (W[0]/2, 0), the coordinate indicating the upper right corner A2[1] (W[0]/2+W[1], 0), the coordinate indicating the lower left corner A3[1] (W[0]/2, H[1]), and the coordinate indicating the lower right corner A4[1] (W[0]/2+W[1], H[1]).

In the example shown in FIG. 3, in the first area limitation process, the area including the detected impact position DP is determined to be the lower left quarter of the specific target area with width W[1] and height H[1]. Therefore, the coordinate indicating the upper left corner of the lower left quarter of the previous specific target area is used for the upper left corner A1[2] of the specific target area in the area limitation process of the second loop. In other words, the Y-direction value sumY[2] of the coordinate indicating the upper left corner A1[2] of the specific target area in the area limitation process of the second loop is the sumY[1] of the Y-direction value of the coordinate indicating the upper left corner A1[1] of the previous specific target area plus H[1]/2, which is half the height H[1] of the previous specific target area.

Here, because the Y-coordinate value sumY[1] of the coordinate indicating the upper left corner A1[1] of the specific target area in the first area limitation process was 0, the Y-coordinate value of the coordinate indicating the upper left corner A1[2] of the specific target area in the second loop area limitation process is H[1]/2. Furthermore, sumX[1] (= W[0]/2) is used as the X-coordinate value sumX[2] of the coordinate indicating the upper left corner A1[2] of the specific target area. Therefore, the range of the identified target area in the area limitation process of the second loop is specified by the coordinates indicating the upper left corner A1[2] (W[0]/2, H[1]/2), the coordinates indicating the upper right corner A2[2] (W[0]/2+W[2], H[1]/2), the coordinates indicating the lower left corner A3[2] (W[0]/2, H[1]/2+H[2]), and the coordinates indicating the lower right corner A4[2] (W[0]/2+W[2], H[1]/2+H[2]).

Similarly, the coordinates (sumX[n], sumY[n]) indicating the upper left edge A1[n] of the specific target area are set to the coordinates indicating the upper left edge of the area limited to 1/4 of the previous specific target area, and the area limiting process is repeated to limit the size of the specific target area to 1/4 of the area.

For example, as described above, assume that the initial value areaW of the width of the specific target area is 800 mm, and the initial value areaH of the height of the specific target area is 440 m, and the area is limited to 1/4 of the original area each time the area limiting process is repeated. In this case, for example, after the area limiting process is repeated 8 times, the width W[8] and height W[8] of the specific target area will be 1/65536 (1/8th of 4) of the initial values, and the detected impact position DP will be identified as being within that range. Therefore, for example, if the area limiting process is repeated 10 times, the detected impact position DP will be identified with an accuracy of less than 1 mm based on the width W[10] and height W[10] of the specific target area.

Next, we will explain how to calculate the coordinates (pDX, pDY) indicating the detected impact position DP from the impact sound detected by the acoustic sensors 27-1 to 27-4.

Figure 4 shows an example of an acoustic signal that is output to the control unit 29 when the acoustic sensors 27-1 to 27-4 detect the impact sound generated when the BB bullet 18 hits the target board 23.

For example, when a BB bullet 18 hits the target plate 23, the impact sound of the bullet is detected by acoustic sensors 27-1 to 27-4 in the order of proximity to the impact position of the BB bullet 18. Therefore, acoustic sensors 27-1 to 27-4 detect the impact sound with a time difference according to the distance from the impact position of the BB bullet 18. Also, the acoustic signals output from acoustic sensors 27-1 to 27-4 have a waveform in which the initial amplitude is the largest and the amplitude attenuates over time.

The signal processing board of the control unit 29 performs signal processing to amplify and full-wave rectify the acoustic signals output from the acoustic sensors 27-1 to 27-4, and generate a peak hold signal that holds the peak value of their amplitude. Then, when the integrated value obtained by integrating these peak hold signals becomes equal to or greater than a reference value, the signal processing board of the control unit 29 outputs an impact detection signal indicating the impact detection times T1 to T4, which are the times when the acoustic sensors 27-1 to 27-4 detected the impact, to the personal computer 13. For example, the impact detection times T1 to T4 are the count values of a free running counter built into the control unit 29.

The target shooting application program executed by the personal computer 13 first identifies the minimum time Tmin, which indicates the timing when an impact sound was first detected, among the impact detection times T1 to T4. The target shooting application program then calculates the detection time differences Δt1 to Δt4, which are the differences between the impact detection times T1 to T4 and the minimum time Tmin, as shown in the following formula (1). Note that the detection time difference (Δt1 in the example of FIG. 4) between the impact detection times T1 to T4 and the time identified as the minimum time Tmin is 0.

The detection time differences Δt1 to Δt4 calculated in this way can be used to determine the coordinates (pDX, pDY) indicating the detected impact position DP, as shown in the following equation (2).

Alternatively, the coordinates (pDX, pDY) indicating the detected impact position DP may be calculated using the detection time differences Δt1 to Δt3, without using the detection time difference Δt4, as shown in the following equation (3).

In this way, the target shooting application program can obtain the impact detection times T1 to T4 at which the impact sounds were detected by the acoustic sensors 27-1 to 27-4, and then calculate the coordinates (pDX, pDY) indicating the detected impact position DP.

Next, we will explain the calculations used to determine the virtual impact positions TP1 to TP4 that are used for comparison with the detected impact position DP in the area limitation process.

For example, as shown in FIG. 5, an arbitrary position on the plane on which the acoustic sensors 27-1 to 27-4 are arranged is designated, and the virtual impact positions TP1 to TP4 are calculated assuming that a bullet has landed at the coordinates (specX, specY) of the designated position T.

The coordinates (X0, Y0) of acoustic sensor 27-1 can be set as the distance in the X and Y directions from (sumX[0], sumY[0]) of the upper left corner A1[0] of the first specific target area. Furthermore, the coordinates (X0+Xs, Y0) of acoustic sensor 27-2, the coordinates (X0, Y0+Ys) of acoustic sensor 27-3, and the coordinates (X0+Xs, Y0+Ys) of acoustic sensor 27-4 are set based on the coordinates (X0, Y0) of acoustic sensor 27-1, in accordance with the spacing Xs in the X direction and the spacing Ys in the Y direction between acoustic sensors 27.

Then, using these coordinates and the distance Z0 from the surface of the target plate 23 to the center of the acoustic sensor 27, the distances L1 to L4 from the specified position T to the acoustic sensors 27-1 to 27-4 can be calculated based on Pythagoras' theorem, as shown in the following equation (4).

Specifically, when the target device 11 shown in FIG. 2 is designed to fit the size of a 32-inch wide display 12, the distance Xs between the acoustic sensors 27 in the X direction is set to 595 mm, and the distance Ys between the acoustic sensors 27 in the Y direction is set to 433.8 mm. Similarly, the coordinates (X0, Y0) of the acoustic sensor 27-1 are set to (102.5 mm, 3.1 mm), and the distance Z0 from the surface of the target plate 23 to the center of the acoustic sensor 27 is set to 9.0 mm.

The target shooting application program then calculates the distances L1 to L4 by calculating formula (4) based on these settings, and identifies the shortest of these as the minimum distance m. The target shooting application program then calculates the distance differences ΔL1 to ΔL4, which are the differences between the distances L1 to L4 and the minimum distance m, as shown in the following formula (5). Note that the distance difference between the distances L1 to L4 and the distance identified as the minimum distance m (distance L1 in the example of Figure 5) is 0.

Furthermore, the target shooting application program converts the distance differences ΔL1 to ΔL4 into clock number differences Δct1 to Δct4, as shown in the following formula (6), using the clock number cpm per mm based on the clock number of the free running counter provided on the signal processing board of the control unit 29.

Here, using the minimum distance m and the speed of sound in air k, the distances L1 to L4 and the clock count differences Δct1 to Δct4 are expressed as shown in FIG. 5. That is, in the example shown in FIG. 5, the distance L2 is expressed as m+k×Δct2, the distance L3 is expressed as m+k×Δct3, and the distance L4 is expressed as m+k×Δct4. Note that in the example of FIG. 5, the clock count difference Δct1 is 0.

The clock count differences Δct1 to Δct4 calculated in this way can be used to calculate the coordinates (pTX, pTY) of the hypothetical impact position TP when it is assumed that the bullet has landed at the coordinates (specX, specY) of the specified position T, as shown in the following equation (7).

Alternatively, the clock count differences Δct1 to Δct3 may be used instead of the clock count difference Δct4 to determine the coordinates (pTX, pTY) indicating the virtual impact position TP, as shown in the following equation (8).

Then, in the target system 10, the area limiting process is performed based on a comparison between the detected impact position DP and four virtual impact positions TP1 to TP4, which are virtual impact positions calculated assuming that the bullets have landed at the four corners of the specific target area.

Next, referring to Figures 6 to 9, we will explain the area limiting process that is repeatedly performed in the impact position identification method of the target system 10.

As shown in FIG. 6, when the area limiting process is performed for the first time (loop count n=0), the specific target area is set to a width W[0] and height H[0] that covers the entire surface of the target device 11 so that the area is wider than the acoustic sensors 27-1 to 27-4. In addition, the coordinates (pTX, pTY) of the virtual impact position TP are found by calculating the above-mentioned equations (4) to (8) based on the distances L1 to L4 from the designated position T to the acoustic sensors 27-1 to 27-4.

Then, when the area limiting process is performed for the first time, the coordinates (specX, specY) of the specified position T are specified as (sumX[0], sumY[0]) of the upper left corner A1[0] of the specific target area, (sumX[0]+W[0], sumY[0]) of the upper right corner A2[0] of the specific target area, (sumX[0], sumY[0]+H[0]) of the lower left corner A3[0] of the specific target area, and (sumX[0]+W[0], sumY[0]+H[0]) of the lower right corner A4[0] of the specific target area.

As a result, as shown in FIG. 7, the coordinates (pTX1[0], pTY1[0]) of the virtual impact position TP1[0] are calculated by specifying the coordinates (sumX[0], sumY[0]) of the upper left corner A1[0] of the specific target area as the coordinates (specX, specY) of the specified position T. The coordinates (pTX2[0], pTY2[0]) of the virtual impact position TP2[0] are calculated by specifying the coordinates (sumX[0]+W[0], sumY[0]) of the upper right corner A2[0] of the specific target area as the coordinates (specX, specY) of the specified position T. Similarly, the coordinates (pTX3[0], pTY3[0]) of the virtual impact position TP3[0] and the coordinates (pTX4[0], pTY4[0]) of the virtual impact position TP4[0] are calculated.

Then, it is determined which of the four regions obtained by dividing the specific target region of width W[0] and height H[0] vertically and horizontally contains the coordinates (pDX, pDY) of the detected impact position DP, which is the impact position calculated from the acoustic signal detected by the acoustic sensor 27.

For example, the difference between the X-coordinate value pDX of the detected impact position DP and the X-coordinate value pTX1[0] of the virtual impact position TP1[0] (= pDX-pTX1[0]) is the comparison distance XL[0] on the left side of the X-coordinate. The difference between the X-coordinate value pTX2[0] of the virtual impact position TP2[0] and the X-coordinate value pDX of the detected impact position DP (= pTX2[0]-pDX) is the comparison distance XR[0] on the right side of the X-coordinate. Similarly, the difference between the Y-coordinate value pDY of the detected impact position DP and the Y-coordinate value pTY1[0] of the virtual impact position TP1[0] (= pDY-pTY1[0]) is the comparison distance YU[0] on the upper side of the Y-coordinate. Additionally, the difference between the Y-coordinate value pTY3[0] of the virtual impact position TP3[0] and the Y-coordinate value pDY of the detected impact position DP (=pTY3[0]-pDY) is defined as the comparison distance YD[0] on the lower side in the Y direction.

Then, based on the comparison result of comparing the magnitude relationship between the comparison distance XL[0] on the left side of the X direction and the comparison distance XR[0] on the right side of the X direction, and the comparison result of comparing the magnitude relationship between the comparison distance YU[0] on the upper side of the Y direction and the comparison distance YD[0] on the lower side of the Y direction, the area including the coordinates (pDX, pDY) of the detected impact position DP is determined.

For example, if the comparison distance XL[0] on the left side of the X direction is less than or equal to the comparison distance XR[0] on the right side of the X direction, and the comparison distance YU[0] on the upper side of the Y direction is less than or equal to the comparison distance YD[0] on the lower side of the Y direction (XL[0]≦XR[0] & YU[0]≦YD[0]), the area including the coordinates (pDX, pDY) of the detected impact position DP is determined to be the upper left area of the specific target area. Similarly, if the comparison distance XL[0] on the left side of the X direction is greater than the comparison distance XR[0] on the right side of the X direction, and the comparison distance YU[0] on the upper side of the Y direction is less than or equal to the comparison distance YD[0] on the lower side of the Y direction (XL[0]＞XR[0] & YU[0]≦YD[0]), the area including the coordinates (pDX, pDY) of the detected impact position DP is determined to be the upper right area of the specific target area.

In addition, if the comparison distance XL[0] on the left side of the X direction is less than or equal to the comparison distance XR[0] on the right side of the X direction, and the comparison distance YU[0] on the upper side of the Y direction is greater than the comparison distance YD[0] on the lower side of the Y direction (XL[0]≦XR[0] & YU[0]＞YD[0]), the area including the coordinates (pDX, pDY) of the detected impact position DP is determined to be the lower left area of the specific target area. Similarly, if the comparison distance XL[0] on the left side of the X direction is greater than the comparison distance XR[0] on the right side of the X direction, and the comparison distance YU[0] on the upper side of the Y direction is greater than the comparison distance YD[0] on the lower side of the Y direction (XL[0]＞XR[0] & YU[0]＞YD[0]), the area including the coordinates (pDX, pDY) of the detected impact position DP is determined to be the lower right area of the specific target area.

Based on this, in the example shown in Figure 7, since the comparison distance XL[0] on the left side of the X direction is greater than the comparison distance XR[0] on the right side of the X direction, and the comparison distance YU[0] on the upper side of the Y direction is less than or equal to the comparison distance YD[0] on the lower side of the Y direction, the area that includes the coordinates (pDX, pDY) of the detected impact position DP is determined to be the upper right area of the specific target area.

Therefore, the specific target area used in the area limitation process of the first loop is limited to the upper right quarter of the previous specific target area, and the coordinates A1[1] to A4[1] of the four corners of that area are identified as described above with reference to Figure 3.

In other words, as shown in Figure 8, in the area limitation process of the first loop (loop count n = 1), the specific target area is limited to the upper right quarter area of the specific target area shown in Figure 6, and the area limitation process is performed in the same manner as described above.

That is, by specifying (sumX[1], sumY[1]) of the upper left corner A1[1] of the specific target area shown in Figure 8 as the coordinates (specX, specY) of the specified position T, the coordinates (pTX1[1], pTY1[1]) of the virtual impact position TP1[1] are calculated as shown in Figure 9. Similarly, the coordinates (pTX2[1], pTY2[1]) of the virtual impact position TP2[1], the coordinates (pTX3[1], pTY3[1]) of the virtual impact position TP3[1], and the coordinates (pTX4[1], pTY4[1]) of the virtual impact position TP4[1] are calculated.

Then, it is determined which of the four regions obtained by dividing the specific target region of width W[1] and height H[1] vertically and horizontally contains the coordinates (pDX, pDY) of the detected impact position DP, which is the impact position calculated from the acoustic signal detected by the acoustic sensor 27.

In the example shown in FIG. 9, the comparison distance XL[1] on the left side of the X direction is less than or equal to the comparison distance XR[1] on the right side of the X direction, and the comparison distance YU[1] on the upper side of the Y direction is greater than the comparison distance YD[1] on the lower side of the Y direction. Therefore, the area that includes the coordinates (pDX, pDY) of the detected impact position DP is determined to be the lower left area of the specific target area.

Therefore, the specific target area used in the area limitation process of the second loop is limited to the lower left quarter of the previous specific target area, and the coordinates A1[2] to A4[2] of the four corners of that area are identified as described above with reference to Figure 3. Thereafter, the area limitation process is repeated in a similar manner.

Then, by repeating this area limitation process 10 times as described above, the detected impact position DP can be identified with an accuracy of less than 1 mm.

<Example of the configuration of the impact position identification processing device>

Figure 10 is a block diagram showing an example of the configuration of one embodiment of an impact position identification processing device that is realized by a personal computer 13 executing a target shooting application program.

As shown in FIG. 10, the impact position identification processing device 51 is configured to include an impact recognition unit 52, a detected impact position calculation unit 53, a calculation setting processing unit 54, a virtual impact position calculation unit 55, a specific target area limiting unit 56, and a calculation judgment processing unit 57.

For example, the impact recognition unit 52 determines that the BB bullet 18 has landed on the target plate 23 at the timing when the impact detection signal is output from the control unit 29, and recognizes the impact detection times T1 to T4 indicated by the impact detection signal supplied from the control unit 29. The impact recognition unit 52 then identifies the minimum value of the impact detection times T1 to T4 at which the impact sound of the BB bullet 18 was detected by the acoustic sensors 27-1 to 27-4 as the minimum time Tmin indicating the timing when the impact sound was first detected. Based on this, the impact recognition unit 52 calculates the detection time differences Δt1 to Δt4 according to the above-mentioned formula (1). The impact recognition unit 52 then supplies the detection time differences Δt1 to Δt4 to the detected impact position calculation unit 53, and instructs the calculation setting processing unit 54 to start calculating the virtual impact position.

The detected impact position calculation unit 53 uses the detection time differences Δt1 to Δt4 supplied from the impact recognition unit 52 to calculate the coordinates (pDX, pDY) indicating the detected impact position DP according to the above-mentioned formula (2) or formula (3), and supplies them to the specific target area limiting unit 56.

The detected impact position calculation unit 53 is also supplied with a temperature signal indicating the current temperature detected by the temperature sensor 28 in FIG. 2 via the control unit 29. Prior to calculating the detected impact position DP, the detected impact position calculation unit 53 uses a temperature correction coefficient k for the detection time differences Δt1 to Δt4 to perform a correction in accordance with temperature changes in the sound speed, as shown in the following equation (9). By performing such a correction, it is possible to suppress a decrease in measurement accuracy caused by temperature changes, and the detected impact position calculation unit 53 can accurately calculate the coordinates (pDX, pDY) indicating the detected impact position DP.

The calculation setting processing unit 54 stores various initial values required for the process of identifying the impact position in the impact position identification processing device 51. When the calculation setting processing unit 54 is instructed by the impact recognition unit 52 to start calculating the virtual impact position, it sets the initial values for the virtual impact position calculation unit 55. For example, the calculation setting processing unit 54 sets the initial value areaW of the width and the initial value areaH of the height of the specific target area, and the device origin (0, 0) which is the coordinate (sumX[0], sumY[0]) of the upper left corner A1[0] of the specific target area used in the first area limitation process. The calculation setting processing unit 54 also clears (n=0) the loop count n, which indicates the number of times the area limitation process has been repeated.

The virtual impact position calculation unit 55 calculates the coordinates (pTX, pTY) of the virtual impact position TP by calculating the above-mentioned formulas (4) to (8), and repeatedly performs the virtual impact position coordinate calculation process to supply the coordinates to the specific target area limiting unit 56. In the first virtual impact position coordinate calculation process (n=0), the virtual impact position calculation unit 55 performs the process based on the initial value set by the calculation setting processing unit 54, and in the subsequent impact position coordinate calculation processes (n≧1), the virtual impact position calculation unit 55 performs the process based on the result of the specific target area limiting process by the specific target area limiting unit 56.

That is, as described above with reference to FIG. 6 and FIG. 8, the virtual impact position calculation unit 55 specifies the coordinates (specX, specY) of the specified position T as the coordinates (sumX[n], sumY[n]) of the upper left end A1[n] of the specific target area, the coordinates (sumX[n]+W[n], sumY[n]) of the upper right end A2[n], the coordinates (sumX[n], sumY[n]+H[n]) of the lower left end A3[n], and the coordinates (sumX[n]+W[n], sumY[n]+H[n]) of the lower right end A4[n]. As a result, the virtual impact position calculation unit 55 can calculate the coordinates (pTX1[n], pTY1[n]) to (pTX4[n], pTY4[n]) of the four virtual impact positions TP1[n] to TP4[n] corresponding to the coordinates (specX, specY) of the specified positions T.

The specific target area limiting unit 56 performs area limiting processing to limit the specific target area to 1/4 of the area based on the coordinates (pTX, pTY) of the virtual impact position TP supplied from the virtual impact position calculation unit 55, and the coordinates (pTX1[n], pTY1[n]) to (pTX4[n], pTY4[n]) of the four virtual impact positions TP1[n] to TP4[n] supplied from the virtual impact position calculation unit 55.

That is, as described above with reference to FIG. 7 and FIG. 9, first, the specific target area limiting unit 56 obtains the comparison distance XL[n] on the left side of the X direction and the comparison distance XR[n] on the right side of the X direction, and compares their magnitude relationship. Then, if the comparison distance XL[n] on the left side of the X direction is greater than the comparison distance XR[n] on the right side of the X direction, the specific target area limiting unit 56 can determine that the virtual impact position TP is included in the area to the right of the center of the specific target area. On the other hand, if the comparison distance XL[n] on the left side of the X direction is equal to or less than the comparison distance XR[n] on the right side of the X direction, the specific target area limiting unit 56 can determine that the virtual impact position TP is included in the area to the left of the center of the specific target area.

Similarly, the specific target area limiting unit 56 determines the comparison distance YU[n] on the upper side in the Y direction and the comparison distance YD[n] on the lower side in the Y direction, and compares which is larger. Then, if the comparison distance YU[n] on the upper side in the Y direction is greater than the comparison distance YD[n] on the lower side in the Y direction, the specific target area limiting unit 56 can determine that the virtual impact position TP is included in the area below the center of the specific target area. On the other hand, if the comparison distance YU[n] on the upper side in the Y direction is equal to or smaller than the comparison distance YD[n] on the lower side in the Y direction, the specific target area limiting unit 56 can determine that the virtual impact position TP is included in the area above the center of the specific target area.

If the specific target area limiting unit 56 determines that the virtual impact position TP is included in the area to the right of the center of the specific target area, it updates the X-direction coordinate value sumX[n+1] indicating the upper left edge A1[n+1] of the specific target area used in the next area limiting process (n=n+1) (sumX[n+1] = sumX[n] + W[n]/2). On the other hand, if it determines that the virtual impact position TP is not included in the area to the right of the center of the specific target area (it is included on the left side), the X-direction coordinate value sumX[n+1] indicating the upper left edge A1[n+1] of the specific target area used in the next area limiting process (n=n+1) is not updated, and sumX[n] is used as is.

Similarly, if the specific target area limiting unit 56 determines that the virtual impact position TP is included in the area below the center of the specific target area, it updates the Y-direction value sumY[n+1] of the coordinate indicating the upper left corner A1[n+1] of the specific target area used in the next area limiting process (n=n+1) (sumY[n+1] = sumY[n] + H[n]/2). On the other hand, if it determines that the virtual impact position TP is not included in the area below the center of the specific target area (it is included above), the Y-direction value sumY[n+1] of the coordinate indicating the upper left corner A1[n+1] of the specific target area used in the next area limiting process (n=n+1) is not updated, and sumY[n] is used as is.

As will be described later with reference to the flowchart in FIG. 13, the specific target area limiting unit 56 determines whether the virtual impact position TP is included in the specific target area limited to 1/4 specified by the updated upper left corner A1[n+1]. This allows the specific target area to be reliably converged by repeating the area limiting process.

In this way, the specific target area limiting unit 56 limits the specific target area to 1/4 of the area by performing the area limiting process based on the comparison described above, and supplies the coordinates of the upper left corner of that 1/4 of the area (sumX[n+1], sumY[n+1]) to the calculation judgment processing unit 57 as the result of the area limiting process.

The calculation and judgment processing unit 57 increments (n=n+1) the loop count n, which indicates the number of times the area limitation process has been repeated by the specific target area limitation unit 56, and judges whether the loop count n is less than a specified number (for example, the above-mentioned 10 times). If the calculation and judgment processing unit 57 judges that the loop count n is less than the specified number, it supplies the coordinates (sumX[n+1], sumY[n+1]) supplied from the specific target area limitation unit 56 to the virtual impact position calculation unit 55 as indicating the upper left end A1[n+1] of the specific target area in the next area determination process.

On the other hand, if the calculation judgment processing unit 57 judges that the loop count n is not less than the specified count (exceeds the specified count), it outputs the coordinates (sumX[n+1], sumY[n+1]) supplied from the specific target area limiting unit 56 to the subsequent stage as coordinates (pQX, pQY) indicating the target impact position QP. For example, the coordinates (pQX, pQY) indicating the target impact position QP are supplied to a display processing unit that displays the impact mark P shown in FIG. 1, and the impact mark P is displayed, and a score according to its position is calculated and displayed.

In the impact position identification processing device 51 configured as described above, the process of limiting the specific target area to 1/4 of the area based on the comparison is repeated, and the impact position of the BB bullet 18 is identified by narrowing the specific target area. This makes it possible to determine the impact position with higher accuracy compared to a configuration that calculates the impact position based only on the impact sound generated by the acoustic sensor 27, for example.

In other words, if the impact position is calculated based only on the impact sound from the acoustic sensor 27, an error occurs when the detection time difference Δt is calculated, and an error also occurs when calculating the minimum distance m from the detection time difference Δt, resulting in an accumulation of errors. In particular, there was a strong tendency for the error to increase as the distance from the center of the target board 23 increased.

In contrast, the impact position identification processing device 51 identifies the impact position of the BB bullet 18 by repeating the comparison as described above, so that such accumulation of errors does not occur and the impact position can be determined accurately.

In addition, the placement of the acoustic sensor 27 in the impact position identification processing device 51 does not affect the calculation formula for determining the impact position, so the acoustic sensor 27 can be placed freely, improving versatility.

Furthermore, compared to the target system proposed in the above-mentioned Patent Document 1, the impact position identification processing device 51 does not require the preparation of array data in advance, and can identify the impact position with high accuracy and high speed. Also, since the accuracy of the impact position identification processing device 51 is not limited by the array data, it is possible to improve the accuracy of the impact position without limit.

In addition, in the target system 10, the target board 23 is provided so as to cover a wider area than the positions of the acoustic sensors 27-1 to 27-4, and the specific target area when the area limitation process is first performed can be set to include an area outside the acoustic sensors 27-1 to 27-4. This allows the target system 10 to detect the impact position of the BB bullet 18 that has landed on the target board 23 even outside the positions of the acoustic sensors 27-1 to 27-4.

<Impact position identification process>
The process of identifying the impact position of the BB bullet 18 by the impact position identification processing device 51 will be described with reference to the flowcharts of FIGS.

Figure 11 shows a flowchart explaining the impact position identification process.

For example, when the personal computer 13 executes an application program for shooting, processing begins, and in step S11, the impact recognition unit 52 determines whether or not a BB bullet 18 has landed. For example, in a state in which an impact detection signal is not output from the control unit 29, the impact recognition unit 52 determines in step S11 that a BB bullet 18 has not landed, and waits to continue processing until an impact detection signal is output from the control unit 29.

On the other hand, when a bullet impact detection signal is output from the control unit 29, the bullet impact recognition unit 52 determines in step S11 that a BB bullet 18 has impacted, and the process proceeds to step S12.

In step S12, the impact recognition unit 52 recognizes the impact detection times T1 to T4 indicated by the impact detection signal output from the control unit 29. Then, the impact recognition unit 52 instructs the calculation setting processing unit 54 to start calculating the virtual impact position.

In step S13, the impact recognition unit 52 identifies the minimum value among the impact detection times T1 to T4 (count values of the free running counter) recognized in step S12 as the minimum time Tmin, which indicates the timing when the impact sound was first detected.

In step S14, the impact recognition unit 52 calculates the detection time differences Δt1 to Δt4 according to the above-mentioned formula (1) and supplies them to the detected impact position calculation unit 53.

In step S15, the detected impact position calculation unit 53 performs a correction for the detected time differences Δt1 to Δt4 supplied from the impact recognition unit 52 in step S14, based on the temperature signal indicating the current temperature detected by the temperature sensor 28, in accordance with the change in sound speed due to temperature, as shown in the above-mentioned formula (9).

In step S16, the detected impact position calculation unit 53 calculates coordinates (pDX, pDY) indicating the detected impact position DP according to the above-mentioned formula (2) or formula (3) based on the detection time differences Δt1 to Δt4 corrected for the temperature change in sound speed in step S15, and supplies them to the specific target area limiting unit 56.

In step S17, the calculation setting processing unit 54 sets the initial value areaW of the width and the initial value areaH of the height of the specific target area to the virtual impact position calculation unit 55 in response to the instruction from the impact recognition unit 52 in step S12 to start calculating the virtual impact position.

In step S18, the calculation setting processing unit 54 instructs the virtual impact position calculation unit 55 to
The device origin (0, 0) is set as the initial value that will become the coordinates (sumX[0], sumY[0]) of the upper left corner A1[0] of the specific target area.

In step S19, the calculation setting processing unit 54 clears (n=0) the loop count n, which indicates the number of times the area limiting process in step S25 has been repeated.

In step S20, the calculation judgment processing unit 57 judges whether the number of loops n is less than 10. If the calculation judgment processing unit 57 judges that the number of loops n is less than 10, the process proceeds to step S21.

In steps S21 to S24, the virtual impact position calculation unit 55 performs virtual impact position coordinate calculation processing (processing of the flowchart in FIG. 11) to calculate the coordinates (pTX, pTY) of the virtual impact position TP when a bullet lands on the coordinates (specX, specY) of the specified position T.

For example, in step S21, a first virtual impact position coordinate calculation process is performed to determine the coordinates (pTX1[n], pTY1[n]) of the virtual impact position TP1[n] by specifying (sumX[n], sumY[n]) of the upper left end A1[n] of the specific target area as the coordinates (specX, specY) of the specified position T. Also, in step S22, a second virtual impact position coordinate calculation process is performed to determine the coordinates (pTX2[n], pTY2[n]) of the virtual impact position TP2[n] by specifying (sumX[n]+W[n], sumY[n]) of the upper right end A2[n] of the specific target area as the coordinates (specX, specY) of the specified position T. Similarly, in step S23, a third virtual impact position coordinate calculation process is performed to find the coordinates (pTX3[n], pTY3[n]) of virtual impact position TP3[n], and in step S24, a fourth virtual impact position coordinate calculation process is performed to find the coordinates (pTX4[n], pTY4[n]) of virtual impact position TP4[n].

In step S25, the specific target area limiting unit 56 performs area limiting processing (processing of the flowchart in FIG. 12) to limit the specific target area to 1/4 of the area. In the area limiting processing, the specific target area is limited to 1/4 of the area based on a comparison using the coordinates (pDX, pDY) of the detected impact position DP calculated in step S16 and the coordinates (pTX1[n], pTY1[n]) to (pTX4[n], pTY4[n]) of the virtual impact positions TP1[n] to TP4[n] calculated in steps S21 to S24.

In step S26, the calculation judgment processing unit 57 increments the loop count n (n = n + 1), which indicates the number of times the area limiting process in step S25 has been repeated, and then the process returns to step S20.

Then, the same process as described above is repeated until it is determined in step S20 that the number of loops n is not less than 10, and if it is determined that the number of loops n is not less than 10 (it has exceeded 10), the process proceeds to step S27.

In step S27, the calculation judgment processing unit 57 outputs the coordinates (sumX[10], sumY[10]) indicating the upper left end A1[10] of the specific target area of width W[10] and height W[10] obtained by the specific target area limiting unit 56 by repeating the area limiting process ten times as the coordinates (pQX, pQY) indicating the target impact position QP to the subsequent stage.

Figure 12 shows a flowchart explaining the virtual impact position coordinate calculation process performed in steps S21 to S24 of Figure 11.

In step S31, the virtual impact position calculation unit 55 performs various initial settings required to obtain the virtual impact position coordinates. For example, the virtual impact position calculation unit 55 sets the coordinates (X0, Y0) of the acoustic sensor 27-1, the X-direction spacing Xs and the Y-direction spacing Ys between the acoustic sensors 27, the spacing Z0 from the surface of the target plate 23 to the center of the acoustic sensor 27, the number of clocks cpm per mm, etc. Here, as the coordinates (specX, specY) of the specified position T, in step S21, the coordinates (sumX[n], sumY[n]) of the upper left end A1[n] of the specific target area are set, and in step S22, the coordinates (sumX[n]+W[n], sumY[n]) of the upper right end A2[n] of the specific target area are set. Similarly, in step S23, coordinates (sumX[n], sumY[n]+H[n]) indicating the bottom left edge A3[n] of the specific target region are set, and in step S24, coordinates (sumX[n]+W[n], sumY[n]+H[n]) indicating the bottom right edge A4[n] of the specific target region are set.

In step S32, the virtual impact position calculation unit 55 calculates the distances L1 to L4 from the designated position T to the acoustic sensors 27-1 to 27-4 by calculating the above-mentioned equation (4).

In step S33, the virtual impact position calculation unit 55 identifies the shortest distance among the distances L1 to L4 calculated in step S32 as the minimum distance m.

In step S34, the virtual impact position calculation unit 55 calculates the above-mentioned formula (5) to find the distance differences ΔL1 to ΔL4, which are the differences between the minimum distance m identified in step S33 and the distances L1 to L4.

In step S35, the virtual impact position calculation unit 55 converts the distance differences ΔL1 to ΔL4 into clock number differences Δct1 to Δct4 by calculating the above-mentioned equation (6).

In step S36, the virtual impact position calculation unit 55 calculates the above-mentioned formula (7) or formula (8) to find coordinates (pTX, pTY) indicating the virtual impact position TP when it is assumed that the bullet has landed at the coordinates (specX, specY) of the specified position T. That is, in step S21, the coordinates (pTX1[n], pTY1[n]) of the virtual impact position TP1[n] are found, and in step S22, the coordinates (pTX2[n], pTY2[n]) of the virtual impact position TP2[n] are found. Similarly, in step S23, the coordinates (pTX3[n], pTY3[n]) of the virtual impact position TP3[n] are found, and in step S24, the coordinates (pTX4[n], pTY4[n]) of the virtual impact position TP4[n] are found.

Then, the virtual impact position calculation unit 55 supplies the coordinates (pTX, pTY) indicating the virtual impact position TP to the specific target area limiting unit 56, and the virtual impact position coordinate calculation process is terminated.

Figure 13 shows a flowchart explaining the area limiting process performed in step S25 of Figure 11.

In step S41, the specific target area limiting unit 56 determines whether the comparison distance XL[n] (= pDX-pTX1[n]) on the left side of the X direction is greater than the comparison distance XR[n] (= pTX2[n]-pDX) on the right side of the X direction.

If it is determined in step S41 that the comparison distance XL[n] on the left side of the X direction is greater than the comparison distance XR[n] on the right side of the X direction, the process proceeds to step S42. That is, in this case, it is determined that the virtual impact position TP is included in the area to the right of the center of the specific target area.

In step S42, the specific target area limiting unit 56 updates the X-coordinate value sumX[n+1] indicating the upper left corner A1[n+1] of the specific target area to be used in the next area limiting process (n=n+1), and then the process proceeds to step S43. That is, half the width W[n] of the current specific target area is added to the X-coordinate value sumX[n] indicating the upper left corner A1[n] of the current specific target area (sumX[n+1] = sumX[n] + W[n]/2).

On the other hand, if it is determined in step S41 that the comparison distance XL[n] on the left side of the X direction is not greater than (is less than) the comparison distance XR[n] on the right side of the X direction, processing proceeds to step S43. That is, in this case, it is determined that the virtual impact position TP is included in the area to the left of the center of the specific target area, and sumX[n] is used as is for the X-direction value sumX[n+1] of the coordinate indicating the upper left edge A1[n+1] of the specific target area used in the next area limiting process.

In step S43, the specific target area limiting unit 56 determines whether the top left corner A1[n+1] of the specific target area updated in step S42 is to the right of the detected impact position DP (pDX<sumX[n+1]). That is, it checks whether the specific target area after limiting to 1/4 is not including the detected impact position DP as a result of adding half the width W[n] of the current specific target area to the X-axis coordinate value sumX[n] indicating the top left corner A1[n] of the current specific target area in step S42. For example, if the amount of addition in step S42 is too large and the detected impact position DP is not included in the specific target area after limiting to 1/4, the specific target area will not converge, so such a check is necessary.

In step S43, if the specific target area limiting unit 56 determines that the upper left end A1[n+1] of the specific target area updated in step S42 is to the right of the detected impact position DP, processing proceeds to step S44.

In step S44, the specific target area limiting unit 56 adjusts the X-direction value sumX[n+1] of the coordinate indicating the upper left corner A1[n] of the specific target area updated in step S42, and then the process proceeds to step S45. For example, the specific target area limiting unit 56 adjusts the X-direction value sumX[n+1] by subtracting half the width W[n] of the specific target area from the current X-direction value sumX[n+1] (sumX[n+1] = sumX[n+1] - W[n]/2).

On the other hand, if in step S43 the specific target area limiting unit 56 determines that the top left end A1[n+1] of the specific target area updated in step S42 is not to the right (is to the left) of the detected impact position DP, processing proceeds to step S45.

In step S45, the specific target area limiting unit 56 determines whether the upper right corner A2[n+1], obtained by adding the width W[n] to the upper left corner A1[n+1] of the specific target area adjusted in step S44, is to the left of the detected impact position DP (pDX>sumX[n+1]+W[n]). That is, it checks whether the specific target area after limiting to 1/4 is no longer including the detected impact position DP as a result of adjusting the upper left corner A1[n+1] of the specific target area in step S44. For example, if the amount of subtraction in step S44 is too large and the detected impact position DP is not included in the specific target area after limiting to 1/4, the specific target area will not converge, so such a check is necessary.

In step S45, if the specific target area limiting unit 56 determines that the upper right corner A2[n+1] obtained by adding the width W[n] to the upper left corner A1[n+1] of the specific target area adjusted in step S44 is to the left of the detected impact position DP, processing proceeds to step S46.

In step S46, the specific target area limiting unit 56 readjusts the X-direction value sumX[n+1] of the coordinate indicating the upper left corner A1[n] of the specific target area adjusted in step S42, and then the process proceeds to step S47. For example, the specific target area limiting unit 56 readjusts the X-direction value sumX[n+1] by adding half the width W[n] of the specific target area to the current X-direction value sumX[n+1] (sumX[n+1] = sumX[n+1] + W[n]/2).

On the other hand, in step S45, if the specific target area limiting unit 56 determines that the upper right corner A2[n+1] obtained by adding the width W[n] to the upper left corner A1[n+1] of the specific target area adjusted in step S44 is not to the left of the detected impact position DP (it is to the right of it), processing proceeds to step S47. That is, in this case, it is confirmed that the detected impact position DP is included in the specific target area after being limited to 1/4 in the X direction.

In step S47, the specific target area limiting unit 56 determines whether the comparison distance YU[n] (= pDY-pTY1[n]) on the upper side in the Y direction is greater than the comparison distance YD[n] (= pTY2[n]-pDY) on the lower side in the Y direction.

If it is determined in step S47 that the comparison distance YU[n] on the upper side in the Y direction is greater than the comparison distance YD[n] on the lower side in the Y direction, the process proceeds to step S48. In other words, in this case, it is determined that the virtual impact position TP is included in the area below the center of the specific target area.

In step S48, the specific target area limiting unit 56 updates the Y-direction value sumY[n+1] of the coordinate indicating the upper left corner A1[n+1] of the specific target area to be used in the next area limiting process (n=n+1), and then the process proceeds to step S49. That is, half the height H[n] of the current specific target area is added to the Y-direction value sumY[n] of the coordinate indicating the upper left corner A1[n] of the current specific target area (sumY[n+1] = sumY[n] + H[n]/2).

On the other hand, if it is determined in step S47 that the comparison distance YU[n] on the upper Y side is not greater than (is less than) the comparison distance YD[n] on the lower Y side, processing proceeds to step S49. That is, in this case, the virtual impact position TP is determined to be included in the area above the center of the specific target area, and sumY[n] is used as is for the Y-direction value sumY[n+1] of the coordinate indicating the upper left edge A1[n+1] of the specific target area used in the next area limiting process.

In step S49, the specific target area limiting unit 56 determines whether the top left corner A1[n+1] of the specific target area updated in step S48 is below the detected impact position DP (pDY<sumY[n+1]). That is, it checks whether the specific target area after limiting to 1/4 is not including the detected impact position DP as a result of adding half the height H[n] of the current specific target area to the Y-direction value sumY[n] of the coordinate indicating the top left corner A1[n] of the current specific target area in step S48. For example, if the amount of addition in step S48 is too large and the detected impact position DP is not included in the specific target area after limiting to 1/4, the specific target area will not converge, so such a check is necessary.

In step S49, if the specific target area limiting unit 56 determines that the upper left end A1[n+1] of the specific target area updated in step S48 is below the detected impact position DP, processing proceeds to step S50.

In step S50, the specific target area limiting unit 56 adjusts the Y-direction value sumY[n+1] of the coordinate indicating the upper left corner A1[n] of the specific target area updated in step S48, and then the process proceeds to step S51. For example, the specific target area limiting unit 56 adjusts the Y-direction value sumY[n+1] by subtracting half the height H[n] of the specific target area from the current Y-direction value sumY[n+1] (sumY[n+1] = sumX[n+1] - H[n]/2).

On the other hand, in step S49, if the specific target area limiting unit 56 determines that the upper left end A1[n+1] of the specific target area updated in step S48 is not below (is above) the detected impact position DP, processing proceeds to step S51.

In step S51, the specific target area limiting unit 56 determines whether the bottom left edge A3[n+1], obtained by adding the height H[n] to the top left edge A1[n+1] of the specific target area adjusted in step S50, is above the detected impact position DP (pDY>sumY[n+1]+H[n]). That is, it checks whether the specific target area after limiting to 1/4 is no longer including the detected impact position DP as a result of adjusting the top left edge A1[n+1] of the specific target area in step S50. For example, if the amount of subtraction in step S50 is too large and the detected impact position DP is not included in the specific target area after limiting to 1/4, the specific target area will not converge, so such a check is necessary.

In step S51, if the specific target area limiting unit 56 determines that the bottom left edge A3[n+1] obtained by adding the height H[n] to the top left edge A1[n+1] of the specific target area adjusted in step S50 is above the detected impact position DP, processing proceeds to step S52.

In step S52, the specific target area limiting unit 56 readjusts the Y-direction value sumY[n+1] of the coordinate indicating the upper left corner A1[n] of the specific target area adjusted in step S42, and then the process proceeds to step S53. For example, the specific target area limiting unit 56 readjusts the Y-direction value sumY[n+1] by adding half the height H[n] of the specific target area to the current Y-direction value sumY[n+1] (sumY[n+1] = sumY[n+1] + H[n]/2).

On the other hand, in step S51, if the specific target area limiting unit 56 determines that the bottom left edge A3[n+1] obtained by adding the height H[n] to the top left edge A1[n+1] of the specific target area adjusted in step S50 is not above (is below) the detected impact position DP, processing proceeds to step S53. That is, in this case, it is confirmed that the detected impact position DP is included in the specific target area after being limited to 1/4.

In step S53, the specific target area limiting unit 56 supplies the coordinates (sumX[n+1], sumY[n+]) of the top left corner A1[n+1] of the specific target area finally determined in the processing of steps S41 to S52 to the calculation judgment processing unit 57. Then, the calculation judgment processing unit 57 updates the width W[n] and height H[n] of the specific target area (W[n+1] = W[n]/2, H[n+1] = H[n]/2), and then the area limiting process is terminated.

As described above, by repeatedly performing the process of limiting the specific target area to 1/4 of the area based on the comparison and narrowing the specific target area, the impact position of the BB bullet 18 is identified, making it possible to determine the impact position with higher accuracy without accumulating errors.

<Second Configuration Example of Target System>
Fig. 14 is a diagram showing a second configuration example of the target system 10. In Fig. 14, components common to the target system 10 in Fig. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The target system 10A shown in FIG. 14 is different from the target system 10 in FIG. 1 in that it includes a housing 20 that is arranged to surround the target device 11 and the display 12. That is, the target system 10A is configured so that the target device 11 and the display 12 are incorporated inside the housing 20, and the housing 20 is structured so that the entire housing 20 is surrounded by a plate-shaped member except for a front opening provided on the front side of the housing 20.

That is, in the target system 10A, the target image 16 is viewed through the front opening of the housing 20, and the BB bullet 18 fired from the soft air gun 17 enters the housing 20 from the front opening and hits the target device 11.

In this way, by configuring the target device 11 and display 12 as an integrated unit using the housing 20, the target system 10A can be easily installed. In addition, the positional relationship between the target device 11 and the display 12 is fixed, which eliminates the need for adjustments that would be necessary if that positional relationship changes. Furthermore, by fixing the positional relationship between the target device 11 and the display 12, the accuracy of detecting the impact position can be improved.

In addition, in the target system 10A, the fixing members 21 and 22 (FIG. 2) constituting the target device 11 can be fixed to the housing 20, and the support members 25 and 26 can be omitted. As described above, the target device 11 is not rolled up, so either a soft or hard material can be used for the back panel 24.

The processes described with reference to the above flowcharts do not necessarily have to be processed chronologically in the order described in the flowcharts, and may include processes executed in parallel or individually (for example, parallel processing or object-based processing). Also, a program may be processed by a single CPU, or may be processed in a distributed manner by multiple CPUs.

The above-mentioned series of processes can be executed by hardware or software. When executing the series of processes by software, the programs that make up the software are installed from a program recording medium on which the programs are recorded, into a computer built into dedicated hardware, or into a general-purpose personal computer, for example, that can execute various functions by installing various programs.

Figure 15 is a block diagram showing an example of the hardware configuration of a computer that executes the above-mentioned series of processes using a program.

In a computer, a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, and a RAM (Random Access Memory) 103 are interconnected by a bus 104.

An input/output interface 105 is also connected to the bus 104. Connected to the input/output interface 105 are an input unit 106 including a keyboard, mouse, microphone, etc., an output unit 107 including a display, speaker, etc., a storage unit 108 including a hard disk or non-volatile memory, a communication unit 109 including a network interface, etc., and a drive 110 that drives removable media 111 such as a magnetic disk, optical disk, magneto-optical disk, or semiconductor memory.

In a computer configured as described above, the CPU 101 loads a program stored in the storage unit 108, for example, into the RAM 103 via the input/output interface 105 and the bus 104, and executes the program, thereby performing the above-mentioned series of processes.

The programs executed by the computer (CPU 101) are provided, for example, by recording them on removable media 111, which is a package medium such as a magnetic disk (including a flexible disk), an optical disk (CD-ROM (Compact Disc-Read Only Memory), DVD (Digital Versatile Disc), etc.), a magneto-optical disk, or a semiconductor memory, or via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

The program can be installed in the storage unit 108 via the input/output interface 105 by inserting the removable medium 111 into the drive 110. The program can also be received by the communication unit 109 via a wired or wireless transmission medium and installed in the storage unit 108. Alternatively, the program can be pre-installed in the ROM 102 or the storage unit 108.

Note that this embodiment is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of this disclosure. In addition, the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

11 target device, 12 display, 13 PC, 14 signal cable, 15 video cable, 16 target image, 17 soft air gun, 18 BB bullet, 19 collection mat, 20 housing, 21 and 22 fixing member, 23 target plate, 24 back plate, 25 and 26 support member, 27-1 to 27-4 acoustic sensor, 28 temperature sensor, 29 control unit, 30 space, 51 impact position identification processing device, 52 impact recognition unit, 53 detected impact position calculation unit, 54 calculation setting processing unit, 55 virtual impact position calculation unit, 56 specific target area limiting unit, 57 calculation judgment processing unit

Claims (6)

a detected impact position calculation unit that calculates a position where an object hits a target board as a detected impact position based on an acoustic signal that detects an impact sound generated when the object hits the target board;
a virtual impact position calculation unit that calculates, by calculation, virtual impact positions that are virtual impact positions that are obtained assuming that the object hits a specified position that is specified on the target plate, and calculates a predetermined number of the virtual impact positions corresponding to a predetermined number of the specified positions;
a specific target area limiting unit that limits a size of a specific target area, which is an area that is identified as including the position where the object hits the target plate, to a narrow area having a predetermined ratio to the specific target area based on a comparison between the detected impact position and a predetermined number of the virtual impact positions,
A target system in which the process of limiting the specific target area by the specific target area limiting unit is repeated to narrow the specific target area, thereby identifying the position where the object hits the target plate. the virtual impact position calculation unit determines the virtual impact position by setting four corners of the specific target area as the designated positions;
The target system according to claim 1 , wherein the specific target area limiting unit repeatedly performs a process of limiting the specific target area to one of four areas obtained by dividing the specific target area vertically and horizontally, and narrowing the size of the specific target area to one-quarter of the original size. 3. The target system according to claim 2, wherein the specific target area limiting unit compares the detected impact position with the virtual impact position calculated using four corners of the specific target area as the specified positions, and determines whether the detected impact position is included in an area on the left/right or above/below a center of the specific target area. 4. The target system according to claim 3, wherein the specific target area limiting unit, after limiting the specific target area to a narrow area, checks whether the detected impact position is included in the narrow area, and if the detected impact position is not included, adjusts the position of the narrow area. The target system according to claim 1 , wherein the virtual impact position calculation unit calculates the detected impact position by correcting a detection time difference of the acoustic signals output from a plurality of acoustic sensors in accordance with a current temperature detected by a temperature sensor. calculating a position where the object hits the target plate as a detected impact position based on an acoustic signal obtained by detecting an impact sound generated when the object hits the target plate;
A virtual impact position is calculated as a virtual impact position that is obtained if the object hits a specified position that is specified on the target plate, and a predetermined number of the virtual impact positions corresponding to the specified positions are calculated;
based on a comparison between the detected impact position and a predetermined number of the virtual impact positions, limiting a size of a specific target area, which is an area identified as including the position where the object hits the target plate, to a narrow area having a predetermined ratio to the specific target area;
A program for a target system that causes a computer to execute a process of repeatedly limiting the specific target area and narrowing the specific target area to thereby identify the position where the object hit the target plate.

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