KR102275202B1 - Flooding Signal Detection Kit - Google Patents

Abstract

The present invention relates to an immersion signal detection kit, which includes: an immersion sensor comprising a pair of metal electrodes; a signal collecting and transmitting/receiving unit collecting signals from the immersion sensor and transmitting a signal to the outside through a short-range wireless communication module when determined as an immersed state; a battery supplying power to the immersion sensor and the signal collecting and transmitting/receiving unit; a case accommodating the immersion sensor, the signal collecting and transmitting/receiving unit, and the battery; and a cradle unit for detachably attaching the case to the wall. According to the present invention as described above, it is possible to provide a low-cost and high-accuracy immersion detection device. Therefore, the possibility of creating a market for the immersion signal detection kit of the present invention is high, and various additional functions can be provided, so as to maximize the user convenience.

Description

Flooding Signal Detection Kit

The present invention relates to a flood signal detection kit in the form of a small kit, and more particularly, it is installed at a place where mechanical facilities such as a machine room, a factory, a farm, etc. are located as well as at home, and detects the flooding of the drain pit and the floor of the facility site, , it relates to a device that transmits it to the site manager through the application.

In order to detect water leakage or flooding in facilities such as roads, underpasses, and dams, various types of flood detection devices are installed and used. However, in the case of the conventional flood warning device, it is impossible to install in a narrow place because the flood detection sensor + warning device + communication device + installation structure are integrated, and various configurations such as installing only the detection sensor separately are impossible. Due to this simplicity, there was an inadequate problem in accommodating the various needs of users.

Accordingly, Korean Patent Registration No. 1343903 discloses a detection sensor installed on the detector body and the detector body to detect a submerged condition, a control unit receiving a signal from the detection sensor, and a wireless communication unit that receives a signal from the control unit and transmits immersion information to the outside; As it consists of a power supply provided in the detector body, it is easy to install and remove the flood alarm, so anyone can install it easily, reduce maintenance costs, and have a small size and easy to move portable flood warning device.

However, the mobile submersion alarm device is a type in which the main body is installed on the floor, and when water flows from a groove in the floor, the detection sensor installed inside the main body detects water ingress. There is a problem that it cannot be reused.

And, in the case of a immersion sensor having two electrodes, a phenomenon in which electricity passes when the electrodes come into contact with water is used, but a detection error may occur when the humidity is high, so more accurate immersion detection is required.

Accordingly, there is a high demand for a portable immersion detection device that can be installed in various indoor places without restrictions on the installation location, can be reused repeatedly, and has an accurate detection capability.

Korea Patent No. 1343903 ‘Mobility flood warning device with built-in detection sensor and mobile flood detection system using the flood warning device’

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a device capable of more accurate detection of immersion while having a compact structure, which can be easily installed on a wall, etc., can be reused repeatedly, and has a simple structure. .

Another object of the present invention is to provide more diverse functions by providing a device capable of interworking with other sensor functions such as access control and air quality detection in addition to the flood detection function.

The immersion signal detection kit for achieving the above object collects a signal from the immersion sensor including a pair of metal electrodes, the immersion sensor, and when it is determined that the immersion state is submerged, the signal is transmitted to the outside through a short-range wireless communication module. A signal collecting and transmitting/receiving unit that transmits, a battery for supplying power to the immersion sensor and the signal collecting and transmitting unit, a case accommodating the immersion sensor, the signal collecting and transmitting/receiving unit and the battery, and the case being detachably attached to the wall It is configured to include a cradle for

Here, the water immersion sensor is installed near an indoor door, third and fourth electrodes are installed on the door or wall, and the first and second electrodes among the pair of metal electrodes are the third and fourth electrodes, respectively. It is possible to be installed at a position corresponding to the electrode to detect the opening and closing of the door.

Alternatively, the pair of metal sensors may have a tubular coupling hole formed therein, and the two terminals of the other sensor module may be coupled to the coupling hole, respectively, to function as a coupling electrode of the other sensor module.

And, the short-distance wireless communication module includes a Wi-Fi communication module, and the signal collection and transmission unit is a Wi-Fi received from a Wi-Fi access point when the immersion detection signal is primarily received from the immersion sensor unit. After analyzing the sub-carrier signal of the signal to determine whether the sub-carrier is submerged or not, it is preferable to transmit the submerged detection signal to the outside when it is determined that the sub-carrier signal is submerged. After the noise component is removed, a waveform corresponding to a change in water level is extracted, and when a waveform change greater than a reference value is detected, it can be determined as immersion.

In addition, the signal collection and transceiver unit calculates phase difference data for n consecutive received signals for a specific subcarrier, detects the frequency of the calculated phase difference data, and converts the detected frequency into a frequency of change of water surface due to immersion. It is possible to decide

According to the present invention as described above, it is possible to provide a low-cost, high-accuracy immersion detection device, which has a high possibility of creating the immersion signal detection kit market of the present invention and provides various additional functions, thereby maximizing user convenience. there is

1A and 1B are a perspective view and a side view showing a schematic configuration of a immersion signal detection kit according to the present invention.
Figure 2 schematically shows a case in which the immersion signal detection kit of the present invention is applied to an access management function.
3 shows a configuration for connecting other sensor modules using the immersion signal detection kit of the present invention.
Fig. 4a shows various paths of a WiFi signal in an indoor WiFi environment, and Fig. 4b shows various paths of a WiFi signal in a state where the room is submerged.
5A is a diagram illustrating a signal including noise in a subcarrier included in a WiFi signal. FIG. 5B illustrates a surface change component extracted through a low-pass filter after noise is removed from the subcarrier signal of FIG. 5A.
6 is a graph comparing the phase (blue dot) measured by a single antenna of the fifth subcarrier of 600 consecutive received signals and the phase difference (red dot) measured by two antennas.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1A and 1B are a perspective view and a side view showing a schematic configuration of a immersion signal detection kit according to the present invention.

1A and 1B, the immersion signal detection kit 1 according to the present invention is a part of the immersion sensor 20 including two metal electrodes 21 and 22 on one side of the case 10 in the form of a small kit. is formed to protrude to the outside, and the two metal electrodes 21 and 22 of the immersion sensor 20 are electrically connected to the signal collection and transmission/reception unit 30 .

The signal collection and transmission/reception unit 30 is formed on a PCB substrate, and includes a CPU and a wireless communication module for signal collection and processing. Here, as the wireless communication module, a WiFi module, a Bluetooth module, a Zigbee module, etc. may be used as a short-range wireless communication module, and a WiFi module is preferably used for secondary immersion detection to be described later.

The CPU is a processor having a general signal processing function, and is implemented to perform functions such as collection and analysis of submerged detection signals, and driving a short-range wireless communication module.

The short-range wireless communication module wirelessly transmits a signal through the antenna 40 , and the antenna 40 may receive a wireless signal from a nearby wireless communication device. In this embodiment, the antenna 40 may receive a WiFi signal transmitted from an AP (Access Point).

Although the kit of the present invention may receive power through a wire, it is preferable to include a battery 50 so that it can be used in a non-powered environment as it is portable.

And, the kit of the present invention is preferably installed on the back side of the case (60) so that it can be detachably installed on the wall of the room (60).

Through this structure, the flood signal detection kit of the present invention is installed on the wall of the room, and when the water level is high due to flooding of the room, it is possible to detect flooding through the two metal electrodes 21 and 22, and the signal collecting and transmitting/receiving unit 30 ) transmits a flood detection signal to a preset manager terminal, and then turns off the power to prevent malfunction of the device due to flooding.

2 and 3 below exemplify the use of the kit of the present invention for other sensor applications.

Figure 2 schematically shows a case in which the immersion signal detection kit of the present invention is applied to an access control function. The kit 1 of the present invention is installed on one side of the wall where the door is installed, and the door is equipped with the kit 1 The third and fourth electrodes 200 and 300 are installed at positions corresponding to the first and second electrodes 21 and 22 . Accordingly, in a state in which the door is closed, the contacts between the electrodes are maintained in a connected state, and when the door is opened, the contacts between the electrodes are opened to detect the opening of the door.

To this end, the signal collection and transmission/reception unit 30 may be equipped with S/W for detecting door opening and implementing an access management system through door opening and closing in addition to a flood detection function.

Meanwhile, FIG. 3 shows a configuration for connecting other sensor modules using the immersion signal detection kit of the present invention. Here, the other sensor modules may be various sensors such as a temperature sensor, a humidity sensor, and an air quality sensor.

In the case of providing a connection function for other sensors, the first and second electrodes 21 and 22 may perform a female connector function, and for this purpose, the first and second electrodes 21 and 22 are open to the inside of the circular electrode. It may be formed in a female connector structure of a single sensor, and the electrodes 400 of other sensors are coupled to the first and second electrodes 21 and 22 in a male and female form.

Although the first and second electrodes 21 and 22 are illustrated as having a female connector structure in FIG. 3 , they may be formed in the form of a male connector or may be formed in a connector structure capable of electrical connection in various other forms.

Figure 4a shows the various paths of the WiFi signal in the indoor WiFi environment, Figure 4b shows the various paths of the WiFi signal in a state where the room is submerged, Figure 5a is a subcarrier included in the WiFi signal noise showing the signal. FIG. 5B illustrates a surface change component extracted through a low-pass filter after noise is removed from the subcarrier signal of FIG. 5A.

The WiFi standard uses Orthogonal Frequency Division Multiplexing (OFDM) technology. In OFDM, a channel is divided into several sub-carriers and data containing the channel status information is loaded and transmitted on each sub-carrier. do.

In FIG. 4A , several subcarriers transmitted from the AP 100 (Access Point) are received by the WiFi device through multipath. 4A and 4B show multipaths of WiFi signals generated between the AP 100 and the kit 1 of the present invention.

Figure 4a shows the WiFi signal transmission path between the AP 100 and the kit 1 located indoors in a normal state where submergence does not occur, and the transmission path includes a path directly transmitted from the AP 100 to the kit 1 ( bold arrow) and the path (dotted arrow) reflected through the ceiling, wall, floor, etc. and transmitted to the kit 1 . This multi-path characteristic has strength against frequency selective attenuation caused by multi-path.

The signal collecting and transmitting/receiving unit 30 having a WiFi communication module generates channel state information as a channel frequency response for each received sub-carrier.

In an indoor environment, signals propagate through one main path and multiple reflected or refracted paths through walls, floors, and ceilings, creating new propagation paths or changing existing propagation paths. When the water fills up the room by , the reflected or refracted path is changed compared to the state before submersion, and all of these multi-path flows are included in the WiFi reception signal.

When flooding occurs, the water level in a building or facility changes or waves occur on the upper surface, and because the water level changes or waves have a low period, the Butterworth filter has a flat pass band and a smooth transition band. can be used to extract the waveform component according to the water level change component.

FIG. 5A shows a signal including noise in a subcarrier included in the WiFi signal. Since the subcarrier signal included in the WiFi signal contains a lot of noise, it is difficult to directly use it for analysis. Therefore, as shown in FIG. 5B , after noise is removed from the subcarrier signal, only the water surface change component due to immersion can be extracted through the low-pass filter.

When a wave is generated on the upper water surface as water fills up the room due to submersion, the wave generates a fluctuation component in the low frequency band, and a fluctuation component corresponding to the change component of the wave occurs in the waveform of a general sine wave as shown in FIG. 5B.

Therefore, it is possible to find out whether submersion has occurred and the speed of submersion by analyzing the occurrence of such fluctuation components.

To this end, the signal collection and transceiver unit 30 may be equipped with S/W for extracting a waveform component according to a water level change component using a Butterworth filter after removing noise from each sub-carrier of the received WiFi signal. The signal collection and transceiver unit 30 analyzes the WiFi signal received from the AP 100 when a immersion detection signal is detected from the immersion sensor 20 in order to prevent erroneous detection of the immersion sensor 20 and secondary immersion can determine whether Through this, it is possible to more accurately determine whether the water is submerged, and the signal collection and transmission/reception unit 30 wakes up only when a flood detection signal is received, so that it can be used as a low-power kit.

In addition to accurate determination of submergence through WiFi signal analysis, the speed of submersion can be known by calculating the rate of change of waveform from the waveform signal of FIG. 5B, and furthermore, the level of submersion according to the speed of submersion is calculated to provide the corresponding information to the manager terminal. can Through this, it is possible to provide not only accurate information about the occurrence of flooding, but also information such as the degree and speed of flooding with only a very simple kit configuration.

6 is a graph comparing the phases (blue dots) measured from a single antenna of the fifth subcarrier of 600 consecutive received signals and the phase difference (red dots) measured from two antennas.

The signal collection and transceiver unit 30 performs pre-processing such as data calibration, subcarrier selection, and discrete wavelet transformation to detect a submerged state using the phase difference of subcarriers included in the WiFi signal.

The phase difference data of the sub-carrier signal represents a periodic signal having the same frequency as a wave of the water surface caused by immersion, and the frequency of the surface wave may be found by detecting the frequency of the phase difference data.

Therefore, the signal collecting and transmitting/receiving unit 30 calculates phase difference data for n consecutive received signals for a specific sub-carrier, detects the frequency of the calculated phase difference data, and sets the detected frequency of the water surface by immersion. It can be determined by the change frequency.

Referring to FIG. 6 , it can be seen that the antenna phase for the fifth subcarrier is uniformly distributed between 0° and 360° and is unstable, but all phase differences are concentrated in the sector between 190° and 210°, so it is very stable. . From this, it can be seen that using the phase difference value of the sub-carrier can represent a more accurate detection result.

Although the present invention has been described with reference to the above-mentioned preferred embodiments, various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover such modifications and variations as fall within the scope of the present invention.

1: immersion signal detection kit 10: case
20: immersion sensor 21: first electrode
22: second electrode 30: signal collecting and transmitting and receiving unit
40: antenna 50: battery
60: mounting part 100: AP
200: third electrode 300: fourth electrode
400: electrode of another sensor

Claims (6)

an immersion sensor including a pair of metal electrodes;
a signal collecting and transmitting/receiving unit for collecting a signal from the submersion sensor and transmitting a signal to the outside through a short-range wireless communication module when it is determined that the submerged state is in the submerged state;
a battery for supplying power to the immersion sensor and the signal collection and transmission/reception unit;
a case for accommodating the immersion sensor, a signal collection and transmission/reception unit, and a battery; and
Comprising a holder for detachably attaching the case to the wall,
The short-distance wireless communication module includes a Wi-Fi communication module, and the signal collection and transceiver unit is a Wi-Fi signal received from a Wi-Fi access point when the immersion detection signal is primarily received from the immersion sensor unit. Submerged signal detection kit, characterized in that after secondarily determining whether the sub-carrier is submerged by analyzing the sub-carrier signal, and transmitting the submerged detection signal to the outside when it is determined that the sub-carrier is submerged.
delete delete delete The method of claim 1,
The signal collection and transceiver unit removes the noise component included in the sub-carrier signal, and then extracts a waveform corresponding to the change in water level, and determines that the signal is submerged when a change in the waveform greater than or equal to a reference value is detected.
The method of claim 1,
The signal collection and transceiver unit calculates phase difference data for n consecutive received signals for a specific subcarrier, detects the frequency of the calculated phase difference data, and determines the detected frequency as a frequency of change of water surface due to immersion. A immersion signal detection kit, characterized in that.

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