Touch detection device for competitive swimming

Abstract

To provide a touch detection device for competitive swimming capable of accurately detecting a swimmer's touch at a low cost.SOLUTION: A touch detection device (11) for competitive swimming includes a bag body (2) filled with fluid and provided within a competitive swimming pool, and a sensor unit (3) using a microphone to detect pressure changes in the fluid inside the bag body (2). The bag body (2) is flexible and is configured such that a portion pressed by a swimmer's touch deforms, and the pressure of the gas inside the bag body (2) changes due to the deformation. By using a pressure sensor with the microphone, the system can be constructed at a low cost.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a touch detection device for competitive swimming used in competitive swimming pools. [Background technology]

[0002] Patent Documents 1 and 2 disclose touch detection devices for competitive swimming that detect pressure changes in a bag using a sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. WO 2021 / 215414 A1 [Patent Document 2] JP 2023-009358 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of the devices described in Patent Documents 1 and 2, there is a problem in that a general pressure sensor is used, which leads to high costs.

[0005] The present invention has been made in consideration of the above circumstances, and a main object of the present invention is to provide a touch detection device for competitive swimming that can solve the above problems. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, one embodiment of a touch detection device for competitive swimming of the present invention is provided in a competitive swimming pool and comprises a bag body filled with fluid and a sensor unit using a microphone that detects pressure changes of the fluid within the bag body, the bag body being flexible and configured so that the portion pressed by the swimmer's touch bends, and this bending changes the pressure of the fluid within the bag body. Effect of the Invention

[0007] According to the present invention, it is possible to realize a touch detection device for competitive swimming that can detect the touch of a swimmer with high accuracy at low cost. [Brief description of the drawings]

[0008] [Figure 1] 1 is a front view showing a configuration of a touch detection device for competitive swimming according to a first embodiment. [Diagram 2] Cross section AB of Figure 1. [Diagram 3] FIG. 11 is a front view showing the configuration of a touch detection device for competitive swimming according to a second embodiment. [Figure 4] Cross-sectional view of Fig. 3 C-D. [Diagram 5] FIG. 11 is a front view showing the configuration of a touch detection device for competitive swimming according to a third embodiment. [Figure 6] FIG. 13 is a front view showing the configuration of a touch detection device for competitive swimming according to a fourth embodiment. [Figure 7] FIG. 4 is a block diagram showing the configuration of a sensor signal processing unit. [Figure 8] FIG. 4 is a block diagram showing a configuration of a sensor signal correction unit. [Figure 9] 5 is a flowchart showing a processing procedure executed by a sensor signal correction unit. [Figure 10] FIG. 4 is a diagram showing an example of a signal waveform of a pressure sensor when touched. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Embodiment 1) Fig. 1 is a front view showing the configuration of a touch detection device for competitive swimming according to the first embodiment, and Fig. 2 is a cross-sectional view taken along line AB of Fig. 1. A touch detection device for competitive swimming according to the present embodiment (hereinafter simply referred to as "touch detection device") 11 includes a substrate 1, a bag 2, a pressure sensor 3 using a microphone, and a pressure sensor signal processing unit 4.

[0010] The substrate 1 is a plate-like member having a rectangular shape in a plan view, and its back surface (the surface at the back in FIG. 1) is installed in close contact with the wall surface 100 of the swimming pool. The bag body 2 is made of a flexible resin tube, and is filled with gas. An example of the gas is air, but any fluid, gas or liquid, can be used. The tubular bag body is commercially available, for example, made of soft polyvinyl chloride with an outer diameter of 6 mm and an inner diameter of 3 mm. (Sanyo Chemical: Oil-resistant fuel tube) Even if the external pressure rises to about 0.5 atmospheres, the tube shape changes only slightly, the internal space is maintained, and flexibility to the touch is maintained. Since the water depth of the swimming pool is about 2 m, the water pressure does not rise above 0.2 atmospheres, so the space inside the bag body is maintained. The air pressure inside the bag body may be set higher than the water pressure to maintain the space. The pressure sensor 3 using a microphone is a sensor that detects the pressure change of the air inside the bag body 2. The sensor signal processing unit 4 is electrically connected to the pressure sensor 3 using a microphone, and processes the sensor signal output from the pressure sensor 3 using a microphone.

[0011] 1, the bag body 2 is bent in a spiral shape and extended on the surface of the substrate 1. Therefore, the bag body 2 is formed so that a straight portion and a bent portion that is bent in a plan view are continuous. As a result, the bag bodies 2 are densely arranged on a two-dimensional plane, so that the bag bodies 2 can reliably receive the touch of a competitive swimmer.

[0012] One end of the bag 2 is attached to the center of the surface of the substrate 1 while being sealed with a plug, and the other end is connected to a pressure sensor 3 using a microphone. The pressure sensor 3 using a microphone outputs a voltage proportional to the change in pressure. The relationship between the output voltage VO (V) and the pressure change P (Pa) can be expressed by Equation 1. An electret condenser microphone has a larger change in output in response to a change in pressure (about -40 dB / P) than a typical pressure sensor, making it possible to simplify the signal processing circuit. Formula 1: VO = P / 50 + 0.5 A pressure increase of 100 Pa results in an increase of 2 V in output.

[0013] When the tube-shaped bag body 2 is pressed by touch with the fingertips of a swimmer, the pressed portion bends. The gas inside the bag body 2 is usually kept at a constant pressure, but when a specific portion of the bag body 2 bends as described above, the pressure of the gas changes according to the bending. The touch detection device 11 becomes able to detect the touch of the swimmer by such a change in the pressure of the gas inside the bag body 2.

[0014] As described above, when the bag 2 is pressed by the swimmer's touch, the force is concentrated on the pressed area of ​​the bag 2, and the gas pressure inside the bag 2 increases instantaneously. Based on this pressure change, the touch can be detected with high accuracy. Even if the tube shrinks slightly due to water pressure, as long as the space is maintained, the pressure increases further due to the swimmer's touch, and the touch can be detected.

[0015] When the bag 2 is touched by a swimmer, the sensor signal of the pressure sensor 3 using a microphone changes as shown in the graph in Figure 10. The time from when the touch occurs until the signal starts to change varies depending on the distance from the touched position on the bag 2 to the pressure sensor 3 using a microphone, but since the speed at which pressure is transmitted is fast at about 300 m / sec, there is not a significant delay. When the pressure is steady at 0.1 MPa (approximately 1 atmosphere), V0 is 0.5 V. When the peak value V1 of the voltage change due to the touch is about 2 V, a pressure change of 100 P occurs. In the case of a sensor using a microphone, the signal is large so an amplifier may be omitted.

[0016] The sensor signal of the pressure sensor 3 using a microphone is input to and processed by the sensor signal processing unit 4. Fig. 7 is a block diagram showing the configuration of the sensor signal processing unit. The sensor signal processing unit 4 includes a low-pass filter 21, a high-pass filter 22, a comparison unit 23, and an output unit 24.

[0017] The low-pass filter 21 removes noise components contained in the sensor signal. The high-pass filter 22 removes changes in the sensor signal due to aging of the bag body 2 or changes in the installation state. The comparison unit 23 compares the signal voltage with a reference voltage, and outputs a signal when the signal voltage exceeds the reference voltage. For example, a touch can be detected by setting the reference voltage for touch detection to about 2.6 V. A hysteresis circuit may be added to prevent erroneous detection due to vibration of the sensor signal. The output unit 24 also sends a pulse signal of a certain width to another device, such as a stopwatch, installed externally. The other device executes a predetermined process based on the pulse signal, thereby obtaining the time of touch by the swimmer. Since the pressure sensor using a microphone has a large output and the DC component is removed, it is possible to omit these signal processing circuits.

[0018] (Embodiment 2) FIG. 3 is a front view showing the configuration of the touch detection device of the second embodiment, and FIG. 4 is a CD sectional view of FIG. 3. The touch detection device 12 of the present embodiment includes a resin bag 6 filled with a gas such as air. The bag 6 has a rectangular shape in a plan view and has an outer diameter slightly smaller than that of the substrate 1. The bag 6 is connected to one end of a tube 6a. The other end of the tube 6a is connected to a pressure sensor 3 using a microphone. Note that the configurations of the substrate 1, the pressure sensor 3 using a microphone, and the sensor signal processing unit 4 are the same as those of the first embodiment, and therefore will not be described.

[0019] As shown in FIG. 4, a plurality of support materials (corresponding to "regulating portions") 5 are provided inside the bag body 6. The support materials 5 are thread-like members that connect the front and back surfaces of the bag body 6, and are arranged in a matrix at predetermined intervals. In this way, the support materials 5 connect the front and back surfaces of the bag body 6, and thus regulate the expansion of the length of the bag body 6 in the thickness direction. In addition, the support materials 5 are bendable in the thickness direction of the bag body 6. Therefore, the support materials 5 do not regulate the shortening of the length of the bag body 6 in the thickness direction. The length of the support materials 5 is, for example, about 6 mm. The support materials may be provided with a strength sufficient to prevent the bag body from being crushed by external pressure due to water pressure and the space from disappearing, or the internal air pressure may be set to be equal to or higher than the water pressure.

[0020] When the swimmer's touch presses the bag body 6, the pressed portion of the bag body 6 bends, and the pressure of the gas in the bag body 6 changes accordingly, as in the case of the first embodiment. The touch detection device 12 becomes able to detect the swimmer's touch by such a change in the pressure of the gas in the bag body 6.

[0021] In this embodiment, the support material 5 restricts the expansion of the thickness direction length of the bag body 6. Therefore, the thickness direction length of the bag body 6 is prevented from exceeding a certain value, and it becomes possible to detect the change in gas pressure caused by the swimmer's touch with high accuracy. Note that the support material 5 does not restrict the shortening of the thickness direction length of the bag body 6, so the pressure on the bag body 6 caused by the swimmer's touch is not hindered.

[0022] In this embodiment, the support material 5 is provided inside the bag body 6, but the support material 5 does not have to be provided. In addition, the support material 5 does not have to be bendable in the thickness direction of the bag body 6. Note that a member similar to the support material 5 may be provided inside the bag body of the other embodiments. For example, inside the tubular bag body 2 in the first embodiment, a thread-like support material 5 may be provided that connects two opposing points on the circumference.

[0023] (Embodiment 3) 5 is a front view showing a configuration of a touch detection device according to a third embodiment. A touch detection device 13 according to the present embodiment includes a tube-shaped bag body 2, as in the first embodiment. This bag body 2 is bent in a meandering manner and extended on the surface of a substrate 1. Therefore, the bag body 2 is formed such that a straight portion and a bent portion that is bent in a plan view are continuous with each other. This allows the bag bodies 2 to be densely arranged on a two-dimensional plane, as in the first embodiment.

[0024] A flexible resin sheet member 7 is provided on the upper surface side of the bag body 2 (the front side in FIG. 5). A plurality of through holes are formed in the sheet member 7. However, the number of through holes may be one or none. The bag body 2 and the sheet member 7 are connected by a connecting member such as a string. In the case of this embodiment, the bag body 2 is touched by a swimmer through the sheet member 7. Even if the fingertips of the swimmer's hand when touching are located in an area where the bag body 2 is not provided (for example, between adjacent tubes), the bag body 2 is also pressed by pressing the sheet member 7, so that a pressure change occurs in the gas inside the bag body 2. The sheet member 7 has flexibility, and when pressed by the touch of the fingertips of the swimmer's hand, the pressed part bends. As a result, the bag body 2 is also pressed by the touch of the swimmer. Note that a member similar to this sheet member 7 may be provided on the upper surface side of the bag body in other embodiments.

[0025] The touch detection device 13 includes a pressure sensor 3 using two microphones, and a two-input sensor signal correction unit 30 electrically connected to each of the microphone pressure sensors 3. Each microphone pressure sensor 3 is connected to each of both ends of the bag body 2. When the bag body 2 is touched by a competitive swimmer, each of the two microphone pressure sensors 3 detects a pressure change in the liquid inside the bag body 2.

[0026] 8 is a block diagram showing the configuration of sensor signal correction unit 30. Sensor signal correction unit 30 includes two sensor signal processing units 31 having the same configuration as sensor signal processing unit 4 in the first embodiment, a microcomputer 32, and an output unit 33 that outputs a pulse signal of a constant width to an external device such as a stopwatch.

[0027] In this embodiment, the sensor signal correction unit 30 corrects the touch time depending on the difference in touch position. Fig. 9 is a flow chart showing the processing procedure executed by the sensor signal correction unit 30. The microcomputer 32 first executes a predetermined initialization process (S1). Thereafter, when a change in the gas pressure in the bag body 2 occurs due to the touch of the swimmer, each sensor signal processing unit 31 receives an input of the detection time of the pressure change from the pressure sensor 3 using each microphone. The microcomputer 32 calculates the difference between these detection times (S2).

[0028] The difference in detection time occurs according to the distance between the position where the bag body 2 is pressed by the swimmer's touch and the pressure sensor 3 using each microphone. Therefore, based on this difference in detection time, the position where the bag body 2 is touched (hereinafter, "touch position") can be identified.

[0029] Next, the microcomputer 32 calculates the time from when the swimmer touches the bag until the change in gas pressure caused by the touch is detected (hereinafter referred to as the "delay time") (S3). This delay time can be calculated if the touch position can be identified. For example, if the touch position is at the center of the tubular bag 2, the delay time TL0 can be found by dividing the distance (L / 2) from the pressure sensor 3 using each microphone to the center of the bag 2 by the pressure propagation speed VP (Equation 2). Formula 2: TL0=(L / 2) / VP On the other hand, if the touch position is close to any of the pressure sensors 3 using a microphone, the delay time TL1 is 2·TLO. The microcomputer 32 calculates the delay time using the touch position identified based on the result of step S2.

[0030] In addition, if a sensor signal is received from only one of the pressure sensors 3 using two microphones, the microcomputer 32 executes fail-safe processing (S4) such as outputting an abnormality signal indicating that the pressure sensor 3 using the other microphone is malfunctioning (always keeping the output signal ON or sending an error code).

[0031] Finally, the microcomputer 32 causes the output unit 33 to output a signal indicating the acquired delay time (S5). An external device that receives this signal uses the delay time to correct the touch time. This allows an accurate touch time to be obtained.

[0032] The above-mentioned delay time is an example of correction information used for correcting the touch time. In addition, the sensor signal correction unit 30 may output, for example, the difference in detection time obtained in step S2 to an external device as correction information. In addition, various information obtained based on the difference in detection time can be used as correction information.

[0033] (Embodiment 4) FIG. 6 is a front view showing the configuration of the touch detection device of the fourth embodiment. The touch detection device 14 of this embodiment includes a tube-shaped bag body 2, as in the first and second embodiments. The bag body 2 has two vertical parts 2a extending in the up-down direction in the figure, and a plurality of horizontal parts 2b extending in the left-right direction in the figure between the vertical parts 2a. One end of each vertical part 2a is connected to a pressure sensor 3 using a microphone. Both ends of each horizontal part 2b are connected to each vertical part 2a, and the vertical part 2a and the horizontal part 2b are in communication with each other. This configuration has the effect of shortening the delay time. The configurations of the substrate 1, the pressure sensor 3 using two microphones, and the sensor signal correction unit 30 are the same as those of the third embodiment, so that the description will be omitted.

[0034] In the present embodiment as well, the bag body 2 is formed so that a straight portion and a bent portion that is bent in a plan view are continuous with each other, thereby making it possible to arrange the bag bodies 2 at high density on a two-dimensional plane.

[0035] The sensor signal correction unit 30 operates in the same manner as in the case of the embodiment 3. This makes it possible to obtain correction information of the touch time.

[0036] (Other embodiments) When the pressure applied to the bag 2, 6 changes due to a change in the amount of water in the swimming pool, the output voltage of the pressure sensor 3 using a microphone also changes, causing a slight change in the reference voltage for determining touch. In such a case, if the pass frequency of the high-pass filter 22 provided in the sensor signal processor 4, 31 is set to about 0.01 Hz or less, the output will not change even if the period is changed by 100 seconds or more, and this effect can be eliminated. Since the DC component is eliminated from the pressure sensor using a microphone, it is possible to omit the high-pass filter. In addition, by making a small hole in the bag or tube in the air and opening it to atmospheric pressure, a highly sensitive sensor based on atmospheric pressure can be used, and the difference in air pressure between inside and outside can be reduced even if the tube changes over time, or the air pressure or water pressure changes. If the hole is small, the effect on the quick pressure change caused by the touch is small, so the effect on touch detection is small.

[0037] In the above-mentioned third and fourth embodiments, the pressure sensors 3 using microphones are disposed on both ends of the tube-shaped bag body 2, but the pressure sensors 3 using microphones may be disposed in different locations. Furthermore, the number of pressure sensors 3 using microphones is not limited to two, and may be three or more. By increasing the number of pressure sensors 3 using microphones, it is possible to improve accuracy and fail-safe performance. The installation locations and number of these pressure sensors 3 using microphones are the same as in the first and second embodiments.

[0038] In the touch detection device of each of the above embodiments, the bags 2 and 6 are provided on the substrate 1, but this is not limited to this. For example, the bags 2 and 6 may be directly attached to the wall of a competitive swimming pool. Although an electret condenser microphone is used as an example of a pressure sensor using a microphone, other types of microphones such as a dynamic microphone or a MEMS microphone may also be used. In addition, smartphones, tablets, etc. are equipped with a microphone input terminal for inputting signals. Microphones compatible with these inputs are small and inexpensive and are commercially available. By connecting it to the bag of the present invention, it can be used as a pressure sensor using a microphone, and a tablet, etc. can be used as a sensor signal processing unit and a time display, making it a low-cost system. [Explanation of symbols]

[0039] 11-14 Touch detection device for competitive swimming 1 Board 2,6 bag body 3. Pressure sensor using a microphone 4 Sensor signal processing section 5 Support materials 7 Sheet material 21 Low-pass filter 22 High-pass filter 23 Comparison section 24 Output section 30 Sensor signal correction section 31 Sensor signal processing unit 32 Microcomputer 33 Output section 100 Wall

Claims

1. A bag provided in the competitive swimming pool and filled with a fluid; a sensor unit using a microphone to detect a pressure change of the fluid in the bag; Equipped with The bag is flexible and configured to bend at a portion pressed by the swimmer's touch, and the pressure of the fluid within the bag changes due to the bending. Touch detection device for competitive swimming.

2. The bag is tubular. The touch detection device for competitive swimming according to claim 1.

3. The bag body is formed so that a straight portion and a bent portion that is bent in a plan view are continuous. The touch detection device for competitive swimming according to claim 2.

4. Flexible sheet member Further equipped with The bag body is connected to the sheet member and is touched by the swimmer through the sheet member. The touch detection device for competitive swimming according to claim 2 or 3.

5. The sheet member has one or more through holes formed therein. The touch detection device for competitive swimming according to claim 4.

6. A restricting portion is provided inside the bag body to restrict the expansion of the length in the thickness direction.

6. The touch detection device for competitive swimming according to claim 1.

7. The restricting portion is bendable in a thickness direction of the bag body. The touch detection device for competitive swimming according to claim 6.

8. The regulating portion has a strength sufficient to maintain the internal space even when the external water pressure is higher than the internal gas pressure to a certain extent. The touch detection device for competitive swimming according to claim 7.

9. A plurality of the sensor units are provided, a correction unit that generates correction information for correcting the time of the touch based on a difference between detection times of the sensor units, 8. The touch detection device for competitive swimming according to claim 1.

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