JP7056244B2 - Counting device - Google Patents

Description

The present invention relates to a counting device.

As a measurement method for detecting the passage of a moving object such as a pedestrian within a predetermined range, a method using an optical camera, a matrix-shaped foot switch, or the like is known (see, for example, Patent Documents 1, 2, etc.). ..

With such a matrix-shaped foot switch method, for example, it is very difficult to distinguish whether a passing object is a person or an article, and image recognition by an optical camera improves the accuracy of an individual. From the viewpoint of information protection, there is a problem that it is difficult to continuously shoot an unspecified number of people.
Therefore, for example, a method of measuring only passage by using the reflection of a sound wave without identifying an individual has been considered (see Patent Document 3 and the like).
However, in such a measurement method, since the reflections are basically integrated in a narrow area or at each point, very complicated data processing is required to improve the accuracy.

The present invention has been made in view of the above, and an object of the present invention is to provide a counting device capable of counting and measuring a moving body with a simple configuration.

The counting device of the present invention has a planar projectile that generates a sound wave having a frequency outside the audible range, and a plurality of directional receivers that measure the intensity of the sound wave generated in a predetermined receiving region. The receiving area of the plurality of directional receivers is characterized in that at least a part thereof is overlapped with each other .

According to the counting device of the present invention, it is possible to provide a counting device capable of counting and measuring a moving body with a simple configuration.

It is a schematic structure of the counting device which concerns on this invention. It is a figure which shows the structural example of the measurement range of the counting apparatus shown in FIG. It is a figure which shows an example of the measurement result by the operation shown in FIG. It is a figure which shows an example of the number of passing people obtained from the directional microphone of a counting device. It is a figure simulating the correspondence relationship between the number of passing people shown in FIG. 4 and the movement of a passerby. It is a figure which shows another example of the measurement result obtained from the directional microphone of a counting device. It is a figure which shows an example of the passing person estimated from the measurement result shown in FIG. It is a figure which shows the structural example of the counting apparatus shown in FIG. It is a figure which shows an example of the structure of the receiving area of the counting apparatus shown in FIG. It is a figure which shows the 1st Example of the planar projectile shown in FIG. It is a figure which shows the 2nd Example of the planar projectile shown in FIG. It is a figure which shows the comparative example 1 of the counting apparatus. It is a figure which shows the comparative example 2 of the counting apparatus.

Hereinafter, the counting device according to the present invention and the first embodiment of the counting method for passersby using the counting device will be described with reference to the drawings.

As shown in FIG. 1, the counting device 100 includes a planar projectile 20 as an ultrasonic generator that generates ultrasonic waves formed in a planar shape under the floor through which a plurality of passersby P to be measured pass. It has directional microphones 30A, 30B, and 30C, which are directional receivers for measuring the intensity of sound waves.
The counting device 100 has a passage detecting unit 40 for confirming the signals from the directional microphones 30A, 30B, and 30C and detecting the passage of the passerby P.
Although three directional microphones are arranged in FIG. 1, one or more microphones may be arranged.
Here, "ultrasonic wave" refers to a sound wave having a frequency outside the human audible range. It is generally known that the planar projectile 20 has a wider irradiation area and a shorter sound wave wavelength, so that the directivity of the sound wave is stronger. Therefore, in this embodiment, ultrasonic waves having a frequency band higher than the audible range are used.

The planar projectile 20 is an ultrasonic generation means, and is a film-shaped ultrasonic transducer having piezoelectricity using polyvinylidene fluoride (PVDF). In addition, lead zirconate titanate (PZT) may be used.

The planar projectile 20 is installed under the floor through which the passerby P passes, and uniformly emits ultrasonic waves upward.

As shown by the broken line in FIG. 1, the directional microphones 30A, 30B, and 30C are sound collectors having directivity for detecting the intensity of a sound wave having a specific wavelength within a predetermined solid angle, and emit a planar surface. It is arranged so that the sound collecting side faces the body 20 side.
In other words, the directional microphones 30A, 30B, and 30C all have a conical reception area 31 having a solid angle θ shown by a long-dotted line in FIG. 1, and the intensity of sound waves generated in the reception area 31. It is a directional receiver that measures.
That is, the intensity of the ultrasonic wave emitted by the planar projectile 20 is measured by the directional microphones 30A, 30B, and 30C.

A counting method for measuring the number of passersby P using such a configuration will be described.
First, the ultrasonic waves emitted by the planar projectile 20 when there is no passerby P are measured by the directional microphones 30A, 30B, and 30C, respectively, and the ultrasonic waveform is detected with a predetermined intensity.
When there is a passerby P in the reception area 31, as shown by the broken line in FIG. 1, there is a “shadow” portion through which ultrasonic waves do not pass, so the directional microphones 30A to 30C detect it according to the area of the shadow. The intensity of the ultrasonic waves produced is reduced.

Here, in order to simplify the explanation, first, as shown in FIGS. 2A to 2C, one passerby P uses a single directional microphone 30A to receive from outside the reception area 31. The case of passing across 31 is measured.
FIG. 3 shows an example of measurement results of changes in the intensity of ultrasonic waves detected by the directional microphone 30A when the passerby P performs such an operation.
When the passerby P is not in the reception area 31, the directional microphone 30A is in a state where all the ultrasonic waves generated in the reception area 31 can be measured.
That is, if the intensity of the ultrasonic wave generated from the planar projectile 20 is kept constant, the intensity of the ultrasonic wave measured by the directional microphone 30A also takes a constant maximum value as shown in FIG. 3A. ..
Next, when the passerby P moves toward the reception area 31, the ultrasonic waves generated from the planar projectile 20 are transiently blocked by the passerby P as shown in FIG. 2 (b). Therefore, as shown in FIG. 3 (b), the intensity of the ultrasonic wave detected by the directional microphone 30A decreases with time.

Further, when the passerby P enters the reception area 31, it becomes the area of the shadow generated by the passerby P, so that the ultrasonic wave blocked by the passerby P becomes a constant amount and is maintained as shown in FIG. 3 (c). ..
When the passerby P leaves the reception area 31, the ultrasonic wave intensity detected by the directional microphone 30A returns to the initial maximum value after passing through the reverse order from the above-mentioned state.
As described above, when one passerby P passes through the reception area 31, the intensity of the ultrasonic wave detected by the directional microphone 30A is stepped in two steps as shown in FIGS. 3 (a) to 3 (c). It fluctuates to.

Similarly, when two passersby P pass through the reception area 31, the intensity of the ultrasonic waves that can be received by the directional microphone 30A is shown in FIGS. 4 and 5 (a), excluding the transient portion. )-(C), it varies in a three-step step of a state where there are 0 people, a state where only 1 person is included, and a state where both are entered.
The intensity value of each of these steps is determined by the size of the reception area 31 and the size of the passerby P, and can be measured in advance, so that the number of people can be grasped relatively easily.
Similarly, for the separation of wheelchairs, children, carry cases, etc. other than passerby P, the size of the passed object is determined from the ratio of the strength value that changes stepwise and the amount of shadow generated by each passerby. It can be roughly guessed.

In this way, by measuring in advance how much the object that may pass affects the intensity of the ultrasonic waves detected by the directional microphone 30A, the object has passed with higher accuracy. It is possible to detect that and its number.

The counting device 100 of the present embodiment has a planar projectile 20 that generates ultrasonic waves, and a directional microphone 30A that measures the intensity of ultrasonic waves generated in a predetermined receiving region 31.
With such a configuration, it is possible to detect an object passing through the reception area 31 without exception with a simple configuration. Furthermore, since no image is used, it is not possible to identify the individual as an individual, and privacy problems can be avoided.

Further, in the present embodiment, the passerby P as a moving body as an object passes between the directional microphone 30A and the planar projectile 20.
By using the transmission type ultrasonic measurement method in this way, it is more resistant to noise such as multiple reflections and ambient noise than the conventional method of emitting ultrasonic waves and estimating the position of a moving object from the reflected waves. Since the S / N ratio is good, it is possible to detect the passerby P with high accuracy.

Using such a configuration, data processing across a plurality of reception areas 31 will be described.
6 (a) and 6 (b) both show an example of data transition when something passes through the reception area 31A of the directional microphone 30A.
The horizontal axis shows the time change, the vertical axis shows the intensity of the sound wave received by the directional microphone 30A, and the numerical value on the vertical axis is 1.0 as an example of the attenuation when one adult passes through.
Now, as in case A shown in FIG. 7A, if an adult passerby P walks on the end of the reception area 31, and only half of the body passes through the reception area 31A, As shown in FIG. 6A, the amount of attenuation is considered to be 0.5.

However, when the same passerby P passes through the center of the reception area 31A as shown in FIG. 7B, the attenuation amount is 1.0 as shown in FIG. 6B. If only a single reception area 31 is used, it is considered that, for example, the amount of attenuation of the reception sensitivity due to the difference in shape may be confused with the amount of attenuation of the reception sensitivity due to the difference in position.

However, as in the present invention, using the plurality of reception areas 31A and the reception area 31B, the passage detection unit 40 detects the number of passersby P so as to ensure the consistency of the signal across the plurality of reception areas. Therefore, it is possible to prevent such confusion.
For example, in the case shown in FIG. 8, in the reception area 31A, since only half of the body of the passerby P passes through, the attenuation amount is 0.5 as shown in FIG. 6A, but the reception area 31A In the adjacent reception area 31B, since the entire body of the passerby P passes through the reception area 31B, the attenuation amount is 1.0.

Therefore, in the counting device 100 of the present embodiment, it is more desirable to arrange the directional microphones 30A, 30B, and 30C in a plurality of columns, for example, in a matrix of 3 rows and 3 columns.
FIG. 9 is a diagram schematically showing the reception areas 31Aa to 31Cc of 3 rows and 3 columns formed by the nine directional microphones 30Aa to Cc arranged in a matrix. Although the reception area is a square for the sake of simplification of the explanation, the reception area is not limited to such a shape, and may have a part that partially overlaps with each other.

As is clear from FIG. 6, in the reception areas 31Aa to 31Cc of 3 rows and 3 columns, an attenuation amount of 0.5 is detected in each of the reception areas 31 adjacent to each other such as the reception area 31Aa and the reception area 31Ba. Occasionally, the passage detection unit 40 can presume that the passerby P is one adult, even if only 0.5 signals are detected.
Therefore, the passage detection unit 40 detects the number of passersby P by using the signals of the plurality of reception areas 31Aa to 31Cc.
With such a configuration, it is possible to detect the passerby P more accurately.

In addition, when two children with an attenuation of 0.5 are walking side by side, it is considered difficult for the two children to walk in perfect synchronization. Therefore, the reception area 31Aa and the reception area 31Ba There is a time lag in the signals detected. The passage detection unit 40 can further improve the accuracy by determining that not only the reception strength but also the reception strength that changes with the passage of time is consistent.

Further, when a large number of passersby P move in various directions, it can be treated as a combination of numerical values of the attenuation amount in the plurality of reception areas.
As a result, when a plurality of directional microphones 30Aa to Cc are used in this way, the image intensity of each pixel changes stepwise corresponding to the reception areas 31Aa to Cc of the directional microphones 30Aa to Cc, which require a large number of pixels. The number of passersby P can be detected by the same treatment as that of a monochrome moving image.
Further, if the circular receiving areas 31Aa to 31Cc are set so that at least a part thereof overlaps, the number of passersby P may be compoundly determined from the signals obtained from the adjacent receiving areas 31Aa, the receiving area 31Ba, and the like. Since it can be determined, the number of passersby P can be estimated more accurately.

As a specific example of using the counting device 100 having such a configuration, a case where a laminated ultrasonic element as shown in Examples 1 and 2 below is used for the planar projectile 20 will be described.

The directivity is controlled by using a drip-proof ultrasonic sensor (PR40-18) made by Nippon Ceramic as a directional microphone 30 and a tubular member, and a plurality of reception areas are formed in a matrix of 3 rows and 3 columns. 31 was formed on the upper surface side of the planar projectile 20. The length of the tubular member of the directional microphone 30 is adjusted so as to form a circular reception area having a diameter of 1.5 m by measuring the size of each reception area while covering each reception area 31 with a shielding plate. There is.

The directional microphone 30 is suspended at a height of 4 m from the reception area 31, and a total of nine microphones are arranged.
It is assumed that the passerby P randomly walks on the reception area 31, and the attenuation of the reception intensity is 1.0 in a state where all the adults are adults and the whole body is in the reception area 31.

(Example 1)
The configuration of the planar projectile 20 used in the first embodiment will be described.
First, barium titanate (manufactured by Wako Pure Chemical Industries, Ltd.) is mixed as an additive with silicone rubber (manufactured by Momentive Performance Materials Japan GK), which is the base material, and PET with an average thickness of 150 ± 20 μm and a width of 120 mm. Roll coat on the film.
The mixture is continuously heated at 120 ° C. for 5 minutes to obtain an intermediate layer precursor.
The intermediate layer precursor is subjected to a surface modification treatment in which a corona discharge treatment is performed in an environment of an applied voltage of 100 V, an integrated energy of 30 J / cm2, and an atmosphere of air.
After surface modification, a 0.1% solution of Optool DSX (manufactured by Daikin Industries, Ltd.) diluted with perfluorohexane is applied to the treated surface by a dipping method with a pulling speed of 10 mm / min. Then, it was held for 30 minutes or more in an environment with a relative humidity of 90% and a temperature of 60 ° C., dried at 50 ° C. for 10 minutes, and then inactive.

Finally, by peeling off the PET film, the intermediate layer 25 of the planar projectile 20 is formed as shown in FIG. The modified surface 25a formed by the surface modification treatment and the inert treatment is formed on both surfaces of the intermediate layer 25. Further, an aluminum sheet having an average thickness of 12 μm is attached to the outside of the modified surface 25a as the first electrode 26a and the second electrode 26b. A 40 kHz amplifier is connected to the first electrode 26a and the second electrode 26b, and the planar projectile 20 has a function as an ultrasonic projectile by applying a voltage.
That is, the first electrode 26a and the second electrode 26b are a pair of electrodes facing each other, and the planar projectile 20 is configured in such a manner that the intermediate layer 25 is sandwiched between the electrodes.
By using the planar projectile 20 having such a configuration, it is possible to measure a moving body in a wider range because it exhibits an inverse piezoelectric operation when a voltage is applied and it is easy to increase the area.
Further, by performing surface treatment (see Patent Document 1 and the like) such as treatment by corona discharge as described above, it is possible to improve the sound pressure generated when a voltage is applied to the planar projectile 20. With this configuration, by applying an alternating voltage of several volts corresponding to ultrasonic waves to the planar projectile 20, sufficient sound pressure to be received by the directional microphone 30 is generated.

(Example 2)
Next, the configuration of the planar projectile 20 used in Example 2 will be described.
In Example 2, as shown in FIG. 11, the intermediate layer 25 is the same as in Example 1, but the conductive cloth tape 27 (Seiwa Electric Co., Ltd.) is located between the intermediate layer 25 and the first electrode 26a. Made) is attached with a width of 5 mm.
As a result, the void layer 28 having a width of 5 mm and a thickness of 0.12 mm is formed in the space surrounded by the conductive cloth tape 27, the first electrode 26a, and the intermediate layer 25.
That is, in the second embodiment, the planar projectile 20 has "a void portion 28 formed between at least one of the surfaces of the intermediate layer 25 on which the surface modification treatment has been performed and the electrode. are doing".
With this configuration, the alternating voltage between the first electrode 26a and the surface-treated surface of the intermediate layer 25 causes electrical attraction, the elasticity of the first electrode 26a returns to the original state, and the surface treatment surface of the intermediate layer 25 returns to the original state. Vibration will be repeated for various reasons.
Although such vibration occurs even without the gap 28, the vibration of the planar projectile 20 becomes more air vibration because the gap 28 is located between the first electrode 26a and the intermediate layer 25. It is preferable because it is easy to transmit (≈ easy to generate sound waves).
Further, although the gap 28 may be on both sides, the sound wave generated in one gap 28 may be resonantly absorbed in the other gap 28, so that the side where the displacement due to vibration is most likely to occur. It is most preferable to provide the gap 28 only on the surface of the surface.

As shown in FIGS. 12 and 13, in addition to Examples 1 and 2, an example using nine reflective ultrasonic sensors 200 is referred to as Comparative Example 1, and the reflective ultrasonic sensor 200 is 30. Comparative Example 2 is an example in which the reception area is finely set by using the individual units.
The number of correct passersby P in each embodiment is taken as the number of passersby, and Table 1 shows the number of passersby P determined to have passed the light receiving range 31 using each of the examples and comparative examples. In this experiment, all passersby P are adults, and when the whole body enters the reception area 31, the attenuation is 1.0, and the initial arrangement is random, assuming that the passersby pass from left to right. In addition, Table 1 shows the results of measuring 12 times by changing the number of passersby P as adults.

As is clear from Table 1, it can be seen that in Examples 1 and 2, the number of passersby P is detected more accurately than in Comparative Example.
When a reflective ultrasonic sensor 200 is used, especially in Comparative Example 1, since the number of reduction errors is large, the number of ultrasonic sensors 200 is too small, and the passerby P that should be detected is omitted. It is thought that it has been closed.
However, if the number of ultrasonic sensors 200 is simply increased as in Comparative Example 2 based on the result of Comparative Example 1, the number of decrease error can be suppressed, but the number of increase error cannot be suppressed. It is considered that this is because the directivity is low and even the reflected sound generated in each other's receiving region is detected only by using many ultrasonic sensors 200.

Therefore, in the embodiment of the present invention, by arranging the planar projectile 20 on the floor side and arranging a plurality of directional microphones 30 above, the number of passersby P moving on the floor can be accurately determined with a simple configuration. It can be detected well.
Further, by arranging so that at least a part of the reception area overlaps, the number of passersby P can be detected more accurately.

Although the embodiments according to the present invention have been described above, the present invention is not limited to each of the above-described embodiments as they are, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. .. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. Further, different embodiments and modifications may be appropriately combined.

20 Planar projectile 30 Directional receiver (directional microphone)
31, 31A, 31B, 31C Reception area 40 Passage detection unit 100 Counting device P Measured object (passerby)

Japanese Unexamined Patent Publication No. 2016-103967 Japanese Patent No. 3218521 Japanese Patent No. 2963236 Japanese Patent No. 2938907

Claims (7)

A planar projectile that produces sound waves with frequencies outside the audible range,
It has a plurality of directional receivers for measuring the intensity of the sound wave generated in a predetermined receiving region, and has.
A counting device characterized in that at least a part of the receiving area of the plurality of directional receivers is overlapped with each other . In the counting device according to claim 1,
The planar projectile and the directional receiver are arranged so as to face each other.
A counting device characterized by detecting an object to be measured that has passed between the planar projectile and the directional receiver. In the counting device according to claim 1 or 2.
A counting device having a passage detecting unit for confirming the consistency between signals in adjacent reception areas . In the counting device according to any one of claims 1 to 3 .
The directional receiver is a counting device mounted above the planar projectile . In the counting device according to any one of claims 1 to 4.
The planar projectile is a counting device characterized by being a film-shaped ultrasonic transducer having piezoelectricity . In the counting device according to any one of claims 1 to 4 .
The planar projectile has a pair of electrodes arranged so as to face each other and an intermediate layer arranged between the pair of electrodes.
The intermediate layer is composed of a material containing at least silicone rubber.
A counting device characterized in that the surface of the intermediate layer on the side facing the electrode is surface-modified by a corona discharge . In the counting device according to claim 6 ,
The planar projectile has a counting device having a gap formed between at least one of the surfaces of the intermediate layer on the surface-modified side and the electrode. ..

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