JP7056179B2 - Submersion determination system and submergence determination method - Google Patents

Description

The present invention relates to a submergence determination system and a submersion determination method.

In Patent Document 1, the distance between the water surface of the bathtub and the upper end of the bather's body is measured by using an ultrasonic wave emitting / receiving device provided on the ceiling of the bathroom, and the bather in the bathtub is measured based on the measurement result. It discloses a technique for determining a submerged state.

Japanese Patent No. 5488995

In FIG. 6, an ultrasonic wave emitting / receiving device 101 is provided on the ceiling located above the bathtub 100 of the bathroom, and the distance between the water surface 102 of the bathtub 100 and the upper end portion 104 of the body of the bather 103 is measured and measured. An example is a technique for determining the submerged state of the bather 103 based on the result. The ultrasonic waves transmitted from the ultrasonic wave emitting / receiving device 101 toward the bathtub 100 are reflected by the water surface 102 of the bathtub 100 and the upper end portion 104 of the body of the bather 103, and are received by the ultrasonic wave emitting / receiving device 101 as reflected waves. ..

FIG. 7 illustrates a reflected wave received by the ultrasonic wave emitting / receiving device 101. (Tx) shows the transmission waveform of the ultrasonic wave transmitted from the ultrasonic wave generation / reception device 101. (Rx) shows the received waveform of the reflected wave received by the ultrasonic wave emitting / receiving device 101. By analyzing the received waveform, the reflected wave w1 from the upper end portion 104 of the body of the bather 103 and the reflected wave w2 from the water surface 102 of the bathtub 100 are separately extracted from the received waveform. The time t1 from when the ultrasonic wave is transmitted from the ultrasonic wave emitting / receiving device 101 until the reflected wave w1 from the upper end portion 104 of the body of the bather 103 is received, and the ultrasonic wave is transmitted from the ultrasonic wave emitting / receiving device 101. The time t2 until the reflected wave w2 from the water surface 102 of the bathtub 100 is received is measured. Based on the difference between the time t1 and the time t2, the distance between the water surface 102 of the bathtub 100 and the upper end portion 104 of the body of the bather 103 is measured.

As shown in FIG. 7, the reflected wave w1 from the upper end portion 104 of the body of the bather 103 has a smaller amplitude than the reflected wave w2 from the water surface 102 of the bathtub 100. This is because the upper end portion 104 of the body of the former bather 103, that is, the crown portion is spherical, while the water surface 102 of the latter bathtub 100 is flat. Therefore, for example, as shown in FIG. 8, when the distance between the water surface 102 of the bathtub 100 and the upper end portion 104 of the body of the bather 103 is short, when analyzing the received waveform, the upper end portion 104 of the body of the bather 103 is used. It becomes difficult to distinguish and extract the reflected wave w1 of the bathtub 100 and the reflected wave w2 from the water surface 102 of the bathtub 100.

Further, FIG. 9 shows a case where the head 105 of the bather 103 is located directly below the ultrasonic wave emitting / receiving device 101. In this case, as shown in FIG. 10, the amplitude of the reflected wave w2 from the water surface 102 of the bathtub 100 becomes significantly small. This is because the ultrasonic waves transmitted directly below the ultrasonic wave emitting / receiving device 101 are blocked by the head 105 of the bather 103, so that the water surface 102 directly below the ultrasonic wave emitting / receiving device 101 cannot be reached. Further, since the ultrasonic wave transmitted obliquely downward from the ultrasonic wave emitting / receiving device 101 is reflected at an equal angle on the water surface 102, the reflected wave is not received by the ultrasonic wave emitting / receiving device 101.

As described above, in the comparative example shown in FIGS. 6 to 10, the reflected wave w1 from the upper end portion 104 of the body of the bather 103 and the reflected wave w2 from the water surface 102 of the bathtub 100 are separately extracted and surely extracted. It is difficult to identify. Therefore, it was not possible to reliably detect whether or not the bather was in a bathing posture that could progress to a submerged state.

Therefore, an object of the present invention is to provide a technique for reliably detecting whether or not a bather is in a bathing posture that may progress to a submerged state.

According to one embodiment of the present invention, the first ultrasonic device and the second ultrasonic device arranged on the ceiling located at the upper part of the bathtub of the bathroom, and the bather may proceed to the submerged state. A submergence determination device for determining whether or not the bathing posture is provided, the first ultrasonic device and the second ultrasonic device are arranged apart from each other in the longitudinal direction of the bathtub, and the first ultrasonic device is provided. The ultrasonic device 1 emits ultrasonic waves diagonally downward so that the ultrasonic waves transmitted from the first ultrasonic device are equiangularly reflected on the water surface of the bathtub and received by the second ultrasonic device. The head, which is configured to transmit, is the distance from the first ultrasonic device to the head of the bather based on the reflected wave received by the first ultrasonic device. The unit distance is calculated, the height position of the water surface is calculated based on the reflected wave received by the second ultrasonic device, and the bather is based on the head distance and the height position of the water surface. A submergence determination system is provided that determines whether or not the bathing posture may progress to a submerged state.

According to another embodiment of the present invention, the bather can proceed to the submerged state by using the first ultrasonic device and the second ultrasonic device arranged on the ceiling located at the upper part of the bathtub of the bathroom. It is a submergence determination method for determining whether or not the bathing posture has a characteristic, and the first ultrasonic device and the second ultrasonic device are arranged apart from each other in the longitudinal direction of the bathtub. In the first ultrasonic device, the ultrasonic waves transmitted from the first ultrasonic device are reflected equiangularly on the water surface of the bathtub and are received by the second ultrasonic device diagonally downward. A step of transmitting a sound wave, a step of calculating a head distance which is a distance from the first ultrasonic device to the head of the bather based on a reflected wave received by the first ultrasonic device, and a step of calculating the head distance. The bather advances to a submerged state based on the step of calculating the height position of the water surface based on the reflected wave received by the second ultrasonic device, and the head distance and the height position of the water surface. A submergence determination method is provided, including a step of determining whether or not the bathing posture may occur.

According to the present invention, it is possible to reliably detect whether or not the bather is in a bathing posture that may progress to a submerged state.

It is a schematic diagram of the submergence determination system. It is a functional block diagram of the submergence determination device. This is the control flow in the submergence determination system. It is a figure which illustrates the received waveform. It is a figure which shows the state of the reflection of the ultrasonic wave when the head of a bather is in the center in the longitudinal direction of a bathtub. It is a figure which shows the state of the reflection of the ultrasonic wave when the head of a bather is not in the center in the longitudinal direction of a bathtub. (Comparative example) It is a figure which illustrates the received waveform. (Comparative example) It is a figure which illustrates the received waveform. (Comparative example) It is a figure which shows the state of the reflection of the ultrasonic wave when the head of a bather is in the center in the longitudinal direction of a bathtub. (Comparative example) It is a figure which illustrates the received waveform. (Comparative example)

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5. In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each layer, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that parts having different dimensional relationships and ratios are included between the drawings.

Further, the embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, and arrangement of components. Etc. are not specified as the following. The technical idea of the present invention can be modified in various ways within the scope of claims.

(Submersion determination system 1)
As shown in FIG. 1, the submersion determination system 1 according to the present embodiment includes a first ultrasonic device 2, a second ultrasonic device 3, a submersion determination device 4, and an alarm device 5.

The first ultrasonic device 2 and the second ultrasonic device 3 are arranged on the ceiling 7 located at the upper part of the bathtub 6 in the bathroom. The first ultrasonic device 2 is arranged above one end 6a in the longitudinal direction of the bathtub 6. The second ultrasonic device 3 is arranged above the other end 6b in the longitudinal direction of the bathtub 6. The first ultrasonic device 2 and the second ultrasonic device 3 are arranged at the same distance from the center 6C in the longitudinal direction of the bathtub 6 in a plan view (not shown).

(First ultrasonic device 2)
The first ultrasonic device 2 is configured to be able to transmit and receive ultrasonic waves. The first ultrasonic device 2 is obliquely downward so that the ultrasonic waves transmitted from the first ultrasonic device 2 are equiangularly reflected on the water surface 8 of the bathtub 6 and received by the second ultrasonic device 3. It is configured to emit ultrasonic waves. The transmission direction of the ultrasonic waves transmitted from the first ultrasonic device 2, that is, the direction in which the acoustic level of the ultrasonic waves transmitted from the first ultrasonic device 2 is maximized and the angle formed by the water surface 8 are described below. It is called the angle θ. The angle θ is a specific example of the transmission angle. In the present embodiment, the angle θ is 15 degrees or more and less than 90 degrees. Preferably, the angle θ is less than 85 degrees, less than 80 degrees, or less than 75 degrees. The directivity characteristic of the ultrasonic wave transmitted by the first ultrasonic device 2 is set so that the intensity of the ultrasonic wave transmitted from the first ultrasonic device 2 directly downward is as small as possible. There is. Specifically, the directivity characteristic of the ultrasonic wave transmitted by the first ultrasonic device 2 is such that all the components within the half-value angle of the main lobe of the ultrasonic wave transmitted by the first ultrasonic device 2 are obliquely downward. It is set. Preferably, the first ultrasonic device 2 may be configured so as not to emit ultrasonic waves directly downward from the first ultrasonic device 2. By setting the directivity as described above, the ultrasonic waves transmitted from the first ultrasonic device 2 are reflected by the water surface 8 and the upper surface 9 of the edge of the bathtub 6 and received by the first ultrasonic device 2. It becomes difficult.

(Second ultrasonic device 3)
The second ultrasonic device 3 is configured to be able to receive ultrasonic waves. However, the second ultrasonic device 3 may be configured to be capable of transmitting ultrasonic waves.

(Submersion determination device 4)
The submergence determination device 4 is a device for determining whether or not the bather P is in a bathing posture that may progress to a submerged state.

The submerged state of bather P is as follows. That is, drowning in the bathtub causes the bather P to become unconscious for some reason when immersed in the hot water of the bathtub 6, or the brain or heart becomes imaginary due to a rapid drop in blood pressure when the bathtub 6 stands up. It occurs when the head Q of the bather P is submerged in the hot water of the bathtub 6 due to a blood state, and the hot water of the bathtub 6 blocks the respiratory organs such as the nose and the mouth. The submerged state of the bather P means a state in which the head Q of the bather P is submerged in the hot water of the bathtub 6.

The submergence determination device 4 is connected to the first ultrasonic device 2 and the second ultrasonic device 3 by wire or wirelessly. The submersion determination device 4 may advance the bather P to a submerged state based on the reflected wave received by the first ultrasonic device 2 and the reflected wave received by the second ultrasonic device 3. Determine if it is in the bathing posture.

(Alarm device 5)
The alarm device 5 is connected to the submergence determination device 4 by wire or wirelessly. The submergence determination device 4 and the alarm device 5 can be installed at any place inside or outside the bathroom. The submergence determination device 4 and the alarm device 5 may be built in either the first ultrasonic device 2 or the second ultrasonic device 3. The alarm device 5 issues a warning when it is determined by the submersion determination device 4 that the bather P is in a bathing posture in which the bather P may progress to the submerged state.

(Detailed explanation of submergence determination device 4)
Hereinafter, the submergence determination device 4 will be described in detail with reference to FIG. 2.

As shown in FIG. 2, the submergence determination device 4 includes a pulse generation circuit 20, an oscillation circuit 21, an intermittent circuit 22, a transmission amplifier circuit 23, a transmission / reception switching circuit 24, a reception amplifier circuit 25, a filter circuit 26, and waveform analysis. A circuit 27, a head reflected wave extraction unit 28, a head distance calculation unit 29, and a head height position calculation unit 30 are provided. Further, the submergence determination device 4 includes a reception amplifier circuit 31, a filter circuit 32, a waveform analysis circuit 33, a water surface reflected wave extraction unit 34, and a water surface height position calculation unit 35. Further, the submersion determination device 4 includes a submersion determination unit 36. The head reflected wave extraction unit 28, the head distance calculation unit 29, the head height position calculation unit 30, the water surface reflected wave extraction unit 34, the water surface height position calculation unit 35, and the submersion determination unit 36 may be, for example, a central processing unit. It is composed of a logic circuit of (Central Processing Unit).

The oscillation circuit 21 generates an AC signal in the ultrasonic band. The pulse generation circuit 20 generates a pulse for determining the ultrasonic wave generation / reception time, and outputs the pulse to the intermittent circuit 22, the transmission / reception switching circuit 24, the waveform analysis circuit 27, and the waveform analysis circuit 33. The intermittent circuit 22 is controlled by a pulse from the pulse generation circuit 20, and makes an AC signal from the oscillation circuit 21 an AC waveform having a pulse-like amplitude. The transmission amplifier circuit 23 amplifies the AC signal from the intermittent circuit 22.

The transmission / reception switching circuit 24 is controlled by the pulse from the pulse generation circuit 20, and switches the transmission / reception of the first ultrasonic device 2. The first ultrasonic device 2 transmits a pulsed ultrasonic wave having a short duration width toward the bathtub 6. Before the ultrasonic waves transmitted from the first ultrasonic wave device 2 become reflected waves and reach the first ultrasonic wave device 2 and the second ultrasonic wave device 3, the transmission / reception switching circuit 24 is subjected to the first transmission / reception switching circuit 24. The connection destination of the ultrasonic device 2 is switched to the receiving amplification circuit 25.

The receiving amplifier circuit 25 amplifies the reflected wave received by the first ultrasonic device 2. The filter circuit 26 removes a frequency component other than the frequency component of the ultrasonic wave transmitted from the first ultrasonic wave device 2 from the reflected wave received by the first ultrasonic wave device 2. The output from the filter circuit 26 is input to the waveform analysis circuit 27.

The waveform analysis circuit 27 performs envelope detection on the received waveform input from the filter circuit 26, and outputs the envelope detection waveform.

The head reflected wave extraction unit 28 extracts the reflected wave at the head Q of the bather P from the reflected wave received by the first ultrasonic device 2 based on the envelope detection waveform output from the waveform analysis circuit 27. Extract.

The head distance calculation unit 29 is a head distance D1 (FIG. 1) which is a distance from the first ultrasonic device 2 to the head Q of the bather P based on the reflected wave at the head Q of the bather P. See). Specifically, in the head distance calculation unit 29, after the ultrasonic wave is transmitted from the first ultrasonic wave device 2, the first ultrasonic wave device 2 receives the reflected wave at the head Q of the bather P. The head distance D1 is calculated by calculating the delay time up to and multiplying this delay time by the propagation speed of ultrasonic waves.

The head height position calculation unit 30 calculates the height position of the head Q of the bather P based on the head distance D1 described above. Specifically, the head height position calculation unit 30 approximates the height position of the head Q of the bather P by subtracting D1 × sin θ from the known height position of the first ultrasonic device 2. Calculate.

The receiving amplifier circuit 31 amplifies the reflected wave received by the second ultrasonic device 3. The filter circuit 32 removes a frequency component other than the frequency component of the ultrasonic wave transmitted from the first ultrasonic wave device 2 from the reflected wave received by the second ultrasonic wave device 3. The output from the filter circuit 32 is input to the waveform analysis circuit 33.

The waveform analysis circuit 33 performs envelope detection on the received waveform input from the filter circuit 32, and outputs the envelope detection waveform.

The water surface reflected wave extraction unit 34 extracts the reflected wave on the water surface 8 from the reflected wave received by the second ultrasonic device 3 based on the envelope detection waveform output from the waveform analysis circuit 33.

The water surface height position calculation unit 35 calculates the height position of the water surface 8 based on the reflected wave on the water surface 8. Specifically, the water surface height position calculation unit 35 calculates the delay time from the transmission of the ultrasonic wave from the first ultrasonic device 2 to the reception of the reflected wave by the second ultrasonic device 3. By multiplying this delay time by the propagation velocity of the ultrasonic wave, the propagation distance D2 (see FIG. 1) of the V-shaped propagation path of the ultrasonic wave reflected at the water surface 8 at an equal angle is calculated. The water surface height position calculation unit 35 is based on the propagation distance D2 and the known separation distance D3 between the first ultrasonic device 2 and the second ultrasonic device 3, and the geometry such as the three-square theorem. The vertical distance D4 between the second ultrasonic device 3 and the water surface 8 is calculated by scientific means. Then, the water surface height position calculation unit 35 calculates the height position of the water surface 8 by subtracting the vertical distance D4 from the known height position of the second ultrasonic device 3.

The submergence determination unit 36 compares the height position of the head Q of the bather P calculated by the head height position calculation unit 30 with the height position of the water surface 8 calculated by the water surface height position calculation unit 35. Then, based on the comparison result, it is determined whether or not the bather P is in a bathing posture that may progress to a submerged state. Specifically, the submergence determination unit 36 calculates the difference between the height position of the head Q of the bather P and the height position of the water surface 8, and when this difference is equal to or less than a predetermined value, the bather is bathed. It is determined that the person P is in a bathing posture that may progress to a submerged state. Here, the predetermined value is appropriately set within the range of, for example, 15 cm to 30 cm, and is preferably determined according to the size of the head Q of the bather P, the position of the respiratory organ, and the like. The predetermined value is set to 25 cm as an example. The predetermined value is stored in advance in a storage device or the like (not shown) of the submergence determination device 4.

The alarm device 5 issues a warning when the submersion determination unit 36 determines that the bather P is in a bathing posture that may progress to a submerged state.

(Submersion judgment method)
Next, a submergence determination method using the submersion determination system 1 according to the embodiment of the present invention will be described. FIG. 3 is a diagram showing a control flow of the submergence determination system 1. FIG. 4 is a diagram illustrating a received waveform.

Step S100:
First, as shown in FIG. 1, the first ultrasonic device 2 transmits ultrasonic waves diagonally downward toward the center 6C in the longitudinal direction of the bathtub 6. In FIG. 1, the head Q of the bather P is located near the other end 6b of the bathtub 6. Of the ultrasonic waves transmitted by the first ultrasonic device 2, the reflected wave reflected by the head Q of the bather P is mainly received by the first ultrasonic device 2. On the other hand, among the ultrasonic waves transmitted by the first ultrasonic device 2, the reflected wave reflected at the water surface 8 at an equal angle is received only by the second ultrasonic device 3 and not by the first ultrasonic device 2. .. This is because the ultrasonic waves transmitted by the first ultrasonic device 2 are obliquely incident on the water surface 8.

Step S110:
Next, the waveform analysis circuit 27 outputs the envelope detection waveform of the reflected wave received by the first ultrasonic device 2 and the second ultrasonic device 3.

Step S120:
Next, the head reflected wave extraction unit 28 reflects from the reflected wave received by the first ultrasonic device 2 at the head Q of the bather P based on the envelope detection waveform output from the waveform analysis circuit 27. Extract the waves. In FIG. 4, (rx1) shows the received waveform of the reflected wave received by the first ultrasonic device 2. As shown in FIG. 4, in the reflected wave received by the first ultrasonic device 2, the reflected wave wQ at the head Q of the bather P has a larger amplitude than the reflected wave w8 at the water surface 8. That is, in the reflected wave received by the first ultrasonic device 2, the amplitude of the reflected wave w8 at the water surface 8 is extremely small as compared with the amplitude of the reflected wave wQ at the head Q of the bather P. .. Therefore, the head reflected wave extraction unit 28 is a reflected wave at the head Q of the bather P from the reflected wave received by the first ultrasonic device 2 based on the envelope detection waveform output from the waveform analysis circuit 27. wQ can be easily extracted.

Step S130:
Next, the water surface reflected wave extraction unit 34 extracts the reflected wave on the water surface 8 from the reflected wave received by the second ultrasonic device 3 based on the envelope detection waveform output from the waveform analysis circuit 33. In FIG. 4, (rx2) shows the received waveform of the reflected wave received by the second ultrasonic device 3. As shown in FIG. 4, in the reflected wave received by the second ultrasonic device 3, the reflected wave w8 on the water surface 8 has an extremely large amplitude than the reflected wave wQ on the head Q of the bather P. That is, in the reflected wave received by the second ultrasonic device 3, the amplitude of the reflected wave wQ at the head Q of the bather P is negligibly smaller than the amplitude of the reflected wave w8 at the water surface 8. It becomes. Therefore, the water surface reflected wave extraction unit 34 easily extracts the reflected wave w8 on the water surface 8 from the reflected wave received by the second ultrasonic device 3 based on the envelope detection waveform output from the waveform analysis circuit 33. be able to.

Step S140:
Next, the head distance calculation unit 29 is the head distance, which is the distance from the first ultrasonic device 2 to the head Q of the bather P, based on the reflected wave wQ at the head Q of the bather P. Calculate D1 (see FIG. 1).

Step S150:
Next, the head height position calculation unit 30 calculates the height position of the head Q of the bather P based on the above head distance D1.

Step S160:
Next, the water surface height position calculation unit 35 calculates the height position of the water surface 8 based on the reflected wave w8 on the water surface 8.

Step S170:
Next, the submergence determination unit 36 calculates the difference between the height position of the head Q of the bather P and the height position of the water surface 8.

Step S180:
Next, the submergence determination unit 36 determines whether or not the difference calculated in step S170 is equal to or less than a predetermined value. When the submergence determination unit 36 determines that the difference is equal to or less than a predetermined value (S180: YES), the submersion determination unit 36 determines that the bather P is in a bathing posture in which the submergence state may progress. On the other hand, when the submersion determination unit 36 determines that the difference is not equal to or less than a predetermined value (S180: NO), the submersion determination unit 36 determines that the bather P is not in a bathing posture that may progress to a submerged state, and ends the process.

Step S190:
The alarm device 5 issues a warning when the submersion determination unit 36 determines that the bather P is in a bathing posture that may progress to a submerged state.

See FIG. 5 here. FIG. 5 shows the state of reflection of ultrasonic waves when the head Q of the bather P is located at the center 6C in the longitudinal direction of the bathtub 6. As shown in FIG. 6, when the head Q of the bather P is located at the center 6C in the longitudinal direction of the bathtub 6, at first glance, the ultrasonic waves transmitted from the first ultrasonic wave device 2 are on the water surface 8. It seems that it cannot be received by the second ultrasonic device 3 as a reflected wave due to equiangular reflection.

However, although the ultrasonic wave has a certain degree of straightness, it does not have a straight line as much as a laser beam, and is diffused and incident on the water surface 8. Further, the ultrasonic wave has a characteristic of diffracting, and the water surface 8 is slightly shaken. Furthermore, the head Q of the bather P is supported by a thin neck, and there is sufficient space on both sides of the neck. Therefore, the ultrasonic waves transmitted from the first ultrasonic device 2 toward the center 6C in the longitudinal direction of the bath 6 pass through the side of the frontal curved surface of the head Q of the bather P and near the shoulder of the bather P. It is possible to reflect at the water surface 8 at an equal angle, pass through the side of the curved surface of the back of the head, and reach the second ultrasonic device 3 as a reflected wave. Therefore, as compared with the comparative example in which the ultrasonic waves are transmitted directly downward as shown in FIG. 6, the ultrasonic waves are transmitted diagonally downward from the first ultrasonic device 2, so that the head Q of the bather P is increased. Regardless of where it is located, it is difficult to prevent the ultrasonic waves transmitted from the first ultrasonic device 2 from being uniformly reflected on the water surface 8 and received by the second ultrasonic device 3 as reflected waves. There is.

The series of procedures shown in FIG. 3 can be executed by controlling the submergence determination system 1 shown in FIG. 1 by a program of an algorithm equivalent to that of FIG. This program may be stored in a storage device or the like (not shown). Further, the program can be stored in a computer-readable recording medium, and the recording medium can be read by the storage device to execute a series of procedures shown in FIG.

Although the embodiment of the present invention has been described above, the above-described embodiment has the following features.

That is, as shown in FIG. 1, the submergence determination system 1 includes a first ultrasonic device 2 and a second ultrasonic device 3 arranged on a ceiling 7 located above a bathtub 6 in a bathroom, and a bather P. It is provided with a submersion determination device 4 for determining whether or not the bathing posture may progress to a submerged state. The first ultrasonic device 2 and the second ultrasonic device 3 are arranged apart from each other in the longitudinal direction of the bathtub 6. The first ultrasonic device 2 is obliquely downward so that the ultrasonic waves transmitted from the first ultrasonic device 2 are equiangularly reflected on the water surface 8 of the bathtub 6 and received by the second ultrasonic device 3. It is configured to emit ultrasonic waves. The submergence determination device 4 calculates a head distance D1 which is a distance from the first ultrasonic device 2 to the head Q of the bather P based on the reflected wave received by the first ultrasonic device 2. The height position of the water surface 8 is calculated based on the reflected wave received by the ultrasonic device 3 of 2, and the bather P may proceed to the submerged state based on the head distance D1 and the height position of the water surface. Determine if it is in a certain bathing posture. According to the above configuration, the reflected wave at the head Q of the bather P can be clearly distinguished from the received waveform in the first ultrasonic device 2, and the reflected wave at the water surface 8 is the second ultrasonic device 3. It can be clearly identified from the received waveform in. Further, the reflected wave transmitted diagonally downward from the first ultrasonic device 2 and reflected on the water surface 8 is received by the second ultrasonic device 3 arranged at a position different from that of the first ultrasonic device 2. Therefore, no matter where the head Q of the bather P is located, the reflected wave reflected at an equal angle on the water surface 8 can be received more reliably. Therefore, according to the above configuration, it is possible to reliably detect whether or not the bather P is in a bathing posture that may progress to a submerged state.

Further, the submersion determination device 4 calculates the height position of the head Q of the bather P based on the transmission angle (angle θ) of the ultrasonic waves by the first ultrasonic device 2 and the head distance D1, and the bather. Based on the height position of the head Q of P and the height position of the water surface 8, it is determined whether or not the bather P is in a bathing posture that may progress to a submerged state. In this way, no matter where the head Q of the bather P to be detected is located when viewed from the first ultrasonic device 2, the head Q of the bather P is approximately the first ultrasonic device. By assuming that it is located in the direction of ultrasonic wave transmission by 2, the height position of the head Q of the bather P can be estimated by a simple calculation formula.

Further, as shown in FIG. 1, the first ultrasonic device 2 is arranged above one end 6a in the longitudinal direction of the bathtub 6, and the second ultrasonic device 3 is the other end 6b in the longitudinal direction of the bathtub 6. Placed above. According to the above configuration, the transmission angle (angle θ) of the ultrasonic waves by the first ultrasonic device 2 can be made smaller, so that the water surface 8 is located no matter where the head Q of the bather P is located. The second ultrasonic device 3 can more reliably receive the reflected wave reflected at the same angle.

Further, as shown in FIG. 1, the first ultrasonic device 2 and the second ultrasonic device 3 are arranged at the same distance from the center 6C in the longitudinal direction of the bathtub 6 in a plan view. However, instead of this, the first ultrasonic device 2 and the second ultrasonic device 3 may be arranged at different distances from the center 6C in the longitudinal direction of the bathtub 6 in a plan view.

Further, as shown in FIG. 3, the bather P is submerged by using the first ultrasonic device 2 and the second ultrasonic device 3 arranged on the ceiling 7 located above the bathtub 6 of the bathroom. The submergence determination method for determining whether or not the bathing posture may progress includes the following steps.
Step S100: The first ultrasonic device 2 so that the ultrasonic waves transmitted from the first ultrasonic device 2 are equiangularly reflected on the water surface 8 of the bathtub 6 and received by the second ultrasonic device 3. Ultrasonic waves are transmitted diagonally downward.
Step S140: The head distance D1, which is the distance from the first ultrasonic device 2 to the head Q of the bather P, is calculated based on the reflected wave received by the first ultrasonic device 2.
Step S160: The height position of the water surface 8 is calculated based on the reflected wave received by the second ultrasonic device 3.
Steps S140, S150, S170, S180: Based on the head distance D1 and the height position of the water surface, it is determined whether or not the bather P is in a bathing posture that may progress to a submerged state. In other words, based on the height position of the head Q of the bather P and the height position of the water surface, it is determined whether or not the bather P is in a bathing posture that may progress to a submerged state.
According to the above method, it is possible to reliably detect whether or not the bather P is in a bathing posture that may progress to a submerged state.

The above-mentioned submergence determination method is realized by the central processing unit of the computer reading the program stored in the storage device and executing the program on the central processing unit.

An underwater ultrasonic sensor may be provided in the bathtub 6, and the presence or absence of a bather may be determined prior to the submergence determination by the ultrasonic sensor.

Further, when determining the submergence, instead of using the height position of the water surface 8 as the threshold value, it is based on the height position of the edge upper surface 9 of the bathtub 6 or the height position of the edge upper surface 9 of the bathtub 6. The height position calculated by the above may be used as a threshold value. The height position of the upper surface 9 of the edge of the bathtub 6 has the property of being equal to the height position of the water surface 8 or higher than the height position of the water surface 8. Therefore, the height position of the upper surface 9 of the edge of the bathtub 6 can be an appropriate threshold value for determining submersion. Further, the height position calculated based on the height position of the edge portion upper surface 9 of the bathtub 6 is, for example, a height position obtained by subtracting a predetermined value from the height position of the edge portion upper surface 9 of the bathtub 6. Can be mentioned.

As described above, it goes without saying that the present invention includes various embodiments not described here. Therefore, the technical scope of the present invention is defined only by the invention extraction matters relating to the reasonable claims from the above description.

1 Submersion determination system 2 First ultrasonic device 3 Second ultrasonic device 4 Submersion determination device 5 Alarm device 6 Bathtub 6a One end 6b End end 6C Central 7 Ceiling 8 Water surface 9 Edge top surface 20 Pulse generation circuit 21 Oscillation circuit 22 Intermittent circuit 23 Transmission amplifier circuit 24 Transmission / reception switching circuit 25 Reception amplifier circuit 26 Filter circuit 27 Waveform analysis circuit 28 Head reflected wave extraction unit 29 Head distance calculation unit 30 Head height position calculation unit 31 Reception amplifier circuit 32 Filter circuit 33 Wave surface analysis circuit 34 Water surface reflected wave extraction unit 35 Water surface height position calculation unit 36 Submersion determination unit D1 Head distance D2 Propagation distance D3 Separation distance D4 Vertical distance P Bather Q Head wQ Reflected wave w8 Reflected wave θ angle

Claims (5)

A first ultrasonic device and a second ultrasonic device placed on the ceiling located at the top of the bathtub in the bathroom, and
A submersion determination device that determines whether or not the bather is in a bathing posture that may progress to a submerged state,
Equipped with
The first ultrasonic device and the second ultrasonic device are arranged apart from each other in the longitudinal direction of the bathtub.
The first ultrasonic device sets the intensity of the ultrasonic wave transmitted directly downward as small as possible, and the ultrasonic wave transmitted from the first ultrasonic device is equal to or equal to the water surface of the bathtub. It is configured to emit the ultrasonic wave diagonally downward so as to be angularly reflected and received by the second ultrasonic device.
The submersion determination device calculates the head distance, which is the distance from the first ultrasonic device to the head of the bather, based on the reflected wave received by the first ultrasonic device, and the second The height position of the water surface is calculated based on the reflected wave received by the ultrasonic device of the above, and the bather may proceed to the submerged state based on the head distance and the height position of the water surface. Judging whether or not it is a bathing posture,
Submergence judgment system. The first ultrasonic device is set so that all the components within the half-value angle of the main lobe of the ultrasonic wave transmitted by the first ultrasonic device are obliquely downward.
The submergence determination system according to claim 1. The submersion determination device calculates the height position of the head of the bather based on the transmission angle of ultrasonic waves by the first ultrasonic device and the head distance, and the height of the head of the bather. Based on the position and the height position of the water surface, it is determined whether or not the bather is in a bathing posture that may progress to a submerged state.
The submergence determination system according to claim 1 or 2 . The first ultrasonic device is arranged above one end in the longitudinal direction of the bathtub.
The second ultrasonic device is located above the other end in the longitudinal direction of the bathtub.
The submergence determination system according to any one of claims 1 to 3 . Using the first ultrasonic device and the second ultrasonic device located on the ceiling located at the top of the bathtub in the bathroom, whether or not the bather is in a bathing posture that may progress to a submerged state. It is a submergence judgment method to judge
The first ultrasonic device and the second ultrasonic device are arranged apart from each other in the longitudinal direction of the bathtub.
The first ultrasonic device diagonally downwards so that the ultrasonic waves transmitted from the first ultrasonic device are equiangularly reflected on the water surface of the bathtub and received by the second ultrasonic device . The step of transmitting the ultrasonic wave and the step of transmitting the ultrasonic wave so that the intensity of the ultrasonic wave transmitted directly downward is reduced as much as possible .
A step of calculating the head distance, which is the distance from the first ultrasonic device to the head of the bather, based on the reflected wave received by the first ultrasonic device.
A step of calculating the height position of the water surface based on the reflected wave received by the second ultrasonic device, and
A step of determining whether or not the bather is in a bathing posture that may progress to a submerged state based on the head distance and the height position of the water surface.
including,
Submergence determination method.

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