Water level measurement device

Abstract

To provide a low-cost water level measurement device.SOLUTION: A water level measurement device 100 includes a long plate-shaped member 1, a transmission circuit 3, and a plurality of antennas 2a to 2g. The transmission circuit 3 is arranged on one end side in a longitudinal direction of the long plate-shaped member 1, is wire-connected to at least two or more antennas among the plurality of antennas 2a to 2g, and stores identification numbers respectively assigned to the wire-connected antennas. The plurality of antennas 2a to 2g are arranged at substantially equal intervals in the longitudinal direction from the other end side in the longitudinal direction of the long plate-shaped member 1, and transmit a radio signal including the identification information according to an instruction from the transmission circuit 3.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a water level measuring device.

Background Art

[0002] In recent years, abnormal weather has increased the frequency of heavy rainfalls. Heavy rainfalls can rapidly raise the water levels of rivers, lakes, etc., and may cause serious floods and other water disasters.

[0003] To prevent such water disasters, it is important to grasp the water levels of rivers, lakes, etc. As a method of grasping the water level, there is a method of installing a water level measuring device in a river, a lake, etc., and monitoring the water level with the device.

[0004] As the water level measuring device, for example, there is known a device that observes the water level by arranging a plurality of IC tags in the vertical direction and detecting that the wireless communication between at least one IC tag submerged due to the rising water level and an IC tag reader has changed from a communicable state to a non-communicable state (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the cost of conventional water level measuring devices has been an obstacle to their widespread use, and in many rivers and the like, the water level is still grasped by on-site confirmation by staff and the like.

[0007] Therefore, an object of the present invention is to provide a low-cost water level measuring device.

Means for Solving the Problems

[0008] In order to achieve the above object, the water level measuring device of the present invention includes a long plate-shaped member, a transmission circuit, and a plurality of antennas. The transmission circuit is arranged at one end side in the longitudinal direction of the long plate-shaped member, and is wired-connected to at least two or more antennas among the plurality of antennas, and stores identification numbers respectively assigned to the wired-connected antennas. The plurality of antennas are arranged at substantially equal intervals in the longitudinal direction from the other end side in the longitudinal direction of the long plate-shaped member, and transmit a radio signal including the identification information according to an instruction from the transmission circuit.

Advantages of the Invention

[0009] According to the present invention, by integrating one transmission circuit for instructing radio signal transmission to two or more antennas, a low-cost water level measuring device can be provided.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0011] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art. All patents, applications, and other publications and information referred to in this specification are hereby incorporated by reference in their entirety.

[0012] Hereinafter, the present invention will be described with examples. However, the present invention is not limited to the following examples and can be arbitrarily modified and implemented. Also, each description in each embodiment of the present invention can be mutually incorporated unless otherwise specified. In this specification, when the expression "~" is used, it is used in the sense of including the numerical or physical values before and after it. Also, in this specification, the expression "A and / or B" includes "only A", "only B", and "both A and B".

[0013] [Water level measuring device] FIG. 1 is a plan view showing an example of the configuration of the water level measuring device of the present invention. As shown in FIG. 1, the water level measuring device 100 of this example includes a long plate-shaped member 1, a transmission circuit 3, and a plurality (seven in this example) of antennas 2a to 2g. In the water level measuring device 100 of this example, there is one transmission circuit 3, and one transmission circuit 3 is wired-connected to all of the plurality of antennas 2a to 2g. The transmission circuit 3 is arranged on one end (the upper end in FIG. 1) side in the longitudinal direction of the long plate-shaped member 1, is wired-connected to the plurality of antennas 2a to 2g, and stores the identification information assigned to each of the plurality of antennas 2a to 2g. The plurality of antennas 2a to 2g are arranged at substantially equal intervals in the longitudinal direction from the other end (the lower end in FIG. 1) side in the longitudinal direction of the long plate-shaped member 1, and transmit a radio signal including the identification information in accordance with an instruction from the transmission circuit 3.

[0014] The material, size, etc. of the long plate-shaped member 1 may be appropriately determined according to the purpose of use of the water level measuring device 100. For example, depending on whether the water level measuring device 100 is used for measuring the water level of a river, a lake, a water channel, etc., the long plate-shaped member 1 may be made of metal, plastic, wood, etc. that can have the strength corresponding to the application, and its length, width, and thickness may be determined according to the application.

[0015] Antennas 2a to 2g are each assigned separate identification information and may be of any type as long as they can transmit a radio signal including the identification information according to an instruction from the transmission circuit 3. As described above, the identification number is stored in the transmission circuit 3. The communication method of antennas 2a to 2g is not particularly limited, and examples include LPWA (Low Power Wide Area) communication methods such as LoRa (registered trademark) and BLE (Bluetooth Low Energy) communication methods. If the LPWA communication method is adopted, for example, communication is possible even if an external receiver that receives the radio signal transmitted from antennas 2a to 2g is at a long distance. In this case, if a router that converts the LPWA communication method to the BLE communication method is interposed between antennas 2a to 2g and the external receiver, an inexpensive BLE communication method external receiver can be used. In this example, the number of antennas is seven, but the number of antennas can be appropriately increased or decreased according to the purpose of use of the water level measuring device 100.

[0016] The transmission circuit 3 may be any device as long as it can store the identification numbers respectively assigned to the wired-connected antennas and can instruct the antennas to transmit a radio signal including the identification information, and a conventionally known device may be used. As described above, in the water level measuring device 100 of this example, there is one transmission circuit 3, and one transmission circuit 3 is wired-connected to all of the plurality of antennas 2a to 2g. However, the transmission circuit 3 may be wired-connected to at least two or more antennas among the plurality of antennas 2a to 2g. As an example, FIG. 2 shows a water level measuring device 101 including two transmission circuits, a transmission circuit 3a wired-connected to the antennas 2a to 2d and a transmission circuit 3b wired-connected to the antennas 2e to 2g. Other points of the water level measuring device 101 shown in FIG. 2 are the same as those of the water level measuring device 100 shown in FIG. 1. In this way, by aggregating the transmission circuits for instructing radio signal transmission to two or more antennas into one, the number of transmission circuits can be made less than half of the number of antennas, and a low-cost water level measuring device can be provided.

[0017] The water level measuring device of the present invention is installed substantially vertically with one end side of the long plate-like member 1 facing upward on the wall surface of, for example, rivers, lakes, waterways, etc., and is used for measuring the water levels thereof. FIG. 3 is a diagram for explaining an example of the usage method of the water level measuring device of the present invention. As shown in FIG. 3, according to the water level measuring device 100, the water level can be measured by detecting which of the identification information respectively assigned to the plurality of antennas 2a to 2g becomes unreceivable. For example, as shown in FIG. 3, at the location where the water level measuring device 100 is installed, it is assumed that the antennas 2f and 2g are below the water surface, while the antennas 2a to 2e are above the water surface. In this case, the radio signals transmitted from the antennas 2f and 2g are blocked by the water, but the radio signals transmitted from the antennas 2a to 2e are not blocked by the water. Then, the identification information included in the radio signals transmitted from the antennas 2f and 2g is not received by the external receiver 4, but the identification information included in the radio signals transmitted from the antennas 2a to 2e is received by the external receiver 4. Thereby, the position between the antenna 2f and the antenna 2e can be measured as the water level.

[0018] Figure 4 is a plan view showing still another example of the configuration of the water level measuring device of the present invention. As shown in Figure 4, the water level measuring device 102 of this example is the same as the water level measuring device 100 shown in Figure 1, except that the long plate-shaped member 1 has a redundant portion 5 where no antenna is arranged at the other end side in the longitudinal direction. According to the water level measuring device 102 of this example, for example, when installed in a river, a lake, etc., the redundant portion 5 can be embedded in the soil such as the river bottom to enhance the installation stability. Further, the redundant portion 5 can also be used for the purpose of height adjustment that can be cut according to the normal water level of the installation location so that the positions of the antennas 2a to 2g are at an appropriate height for measuring the water level at the installation location of the water level measuring device 102.

[0019] Figure 5 is a plan view showing still another example of the configuration of the water level measuring device of the present invention. As shown in Figure 5, the water level measuring device 103 of this example is the same as the water level measuring device 100 shown in Figure 1, except that a plurality of impedance matching circuits 6a to 6g are respectively arranged between the plurality of antennas 2a to 2g and the transmission circuit 3. In the water level measuring device 100 shown in Figure 1, the impedance values of the respective antennas can be different depending on the length of the wired connection between the transmission circuit 3 and each of the plurality of antennas 2a to 2g. On the other hand, according to the water level measuring device 103 of this example, by arranging a plurality of impedance circuits 6a to 6g corresponding to the length of the wired connection between the transmission circuit 3 and each antenna, the impedance values of the plurality of antennas 2a to 2g can be made equal. As a result, the intensity etc. of the radio signals transmitted from each antenna can also be made equal. In this example, as shown in Figure 5, it is preferable to arrange each impedance matching circuit of the plurality of impedance matching circuits 6a to 6g in the vicinity of each of the plurality of antennas 2a to 2g. As the impedance matching circuit, a conventionally known one may be used.

[0020] FIG. 6 is a plan view showing still another example of the configuration of the water level measuring device of the present invention. As shown in FIG. 6, the water level measuring device 104 of this example is the same as the water level measuring device 100 shown in FIG. 1, except that the current detection circuits 7 for detecting the failure of each of the plurality of antennas 2a to 2g are wired-connected to the transmission circuit 3. According to the water level measuring device 104 of this example, for example, the current consumption in each antenna can be monitored by the current detection circuit 7, and the failure of each antenna can be detected by detecting an abnormal current consumption. As the current detection circuit 7, a conventionally known one may be used.

[0021] FIG. 7(A) is a plan view showing still another example of the water level measuring device of the present invention, and FIG. 7(B) is a cross-sectional view in the thickness direction at the broken line portion of FIG. 7(A). As shown in FIGS. 7(A) and 7(B), in the water level measuring device 105 of this example, the secondary battery 8 is disposed at a location other than the locations where the transmission circuit 3, the plurality of antennas 2a to 2g, and their connection wirings (wiring portion 12) are disposed on the long plate-like member 1, and the solar panel 9 is disposed on the secondary battery 8. In FIG. 7(B), reference numeral 2 indicates the locations where the antennas 2a to 2g are disposed. According to the water level measuring device 105 of this example, power can be supplied from at least one of the secondary battery 8 and the solar panel 9 to the transmission circuit 3 and the antennas 2a to 2g, and the water level measuring device 105 installed on the wall surface of a river, a lake, a waterway, etc. can be continuously operated. In the water level measuring device of the present invention, there is no particular limitation on the arrangement locations of the secondary battery 8 and the solar panel 9. However, as shown in FIGS. 7(A) and 7(B), if they are arranged at locations other than above the locations where the plurality of antennas 2a to 2g and their connection wirings (wiring portion 12) are disposed, the area of the secondary battery 8 and the solar panel 9 can be increased and the power generation amount can be increased without disturbing the transmission of radio signals from the antennas 2a to 2g. The power generated by the solar panel 9 may be supplied to the secondary battery 8 and stored in the secondary battery 8. As the secondary battery 8 and the solar panel 9, conventionally known ones may be used.

[0022] As shown in Fig. 7(B), the water level measuring device of the present invention may further include a surface protection layer 10, and the entire laminate in which the long plate-like members 1, the secondary battery 8, the solar panel 9, and the surface protection layer 10 are laminated may be subjected to lamination processing, thereby forming a laminate 11. The surface protection layer 10 may be any one as long as it can protect the surface of the solar panel 9 or the like, and a conventionally known one may be used. The laminate 11 may be any one as long as it can be laminated so as to cover the entire laminate, and a conventionally known one may be used. In the water level measuring device 105 of this example, the configurations other than the secondary battery 8, the solar panel 9, the surface protection layer 10, and the laminate 11 are the same as those of the water level measuring device 100 shown in Fig. 1.

[0023] In the water level measuring device 105 of this example, the lamination order of the secondary battery 8 and the solar panel 9 may be interchanged, and the solar panel 9 may be disposed on the long plate-like member 1 and the secondary battery 8 may be disposed on the solar panel 9. Further, although Figs. 7(A) and 7(B) show an example in which the secondary battery 8 and the solar panel 9 are disposed on one surface of the long plate-like member 1, the secondary battery 8 and the solar panel 9 may be disposed on the other surface of the long plate-like member 1 or on both surfaces.

[0024] The various features of the present invention described in this specification can be combined in various ways, and the aspects obtained by such combinations, including those not specifically described in this specification, are all within the scope of the present invention. Also, those skilled in the art understand that numerous various modifications can be made without departing from the spirit of the present invention, and equivalents including such modifications are also included in the scope of the present invention. Therefore, it should be understood that the aspects described in this specification are merely illustrative and are not intended to limit the scope of the present invention.

Industrial Applicability

[0025] As described above, according to the present invention, by integrating into one a transmission circuit that instructs wireless signal transmission to two or more antennas, a low-cost water level measurement device can be provided. Therefore, the present invention is extremely useful in various fields where water level measurement devices are used.

Explanation of Reference Numerals

[0026] 1 Long plate-shaped member 2a~2g Antenna 3, 3a, 3b Transmission circuit 4 External receiver 5 Redundant portion 6a~6g Impedance matching circuit 7 Current detection circuit 8 Secondary battery 9 Solar panel 10 Surface protection layer 11 Laminate 12 Wiring portion 100~105 Water level measurement device

Claims

1. A water level measuring device comprising a long plate-shaped member, a transmission circuit, and a plurality of antennas, wherein the transmission circuit is arranged on one end side in the longitudinal direction of the long plate-shaped member and is wired-connected to at least two or more of the plurality of antennas, and stores identification numbers respectively assigned to the wired-connected antennas, wherein the plurality of antennas are arranged at substantially equal intervals in the longitudinal direction from the other end side in the longitudinal direction of the long plate-shaped member, and transmit a radio signal including the identification information according to an instruction from the transmission circuit.

2. The water level measuring device according to claim 1, wherein there is one transmission circuit, and the one transmission circuit is wired-connected to all of the plurality of antennas.

3. The water level measuring device according to claim 1 or 2, wherein the transmission of the radio signal is performed by an LPWA (Low Power Wide Area) communication method.

4. The water level measuring device according to any one of claims 1 to 3, wherein the long plate-shaped member has a redundant portion at the other end side in its longitudinal direction where no antenna is arranged.

5. Further comprising a plurality of impedance matching circuits, wherein each impedance matching circuit of the plurality of impedance matching circuits is arranged between the transmission circuit and an antenna wired-connected to the transmission circuit. The water level measuring device according to any one of claims 1 to 4.

6. Further comprising a current detection circuit for detecting a failure of each of the plurality of antennas, wherein the current detection circuit is wired-connected to a transmission circuit wired-connected to each antenna. The water level measuring device according to any one of claims 1 to 5.

7. Further comprising a secondary battery and a solar panel, wherein the secondary battery is arranged at a location other than the locations where the transmission circuit, the plurality of antennas, and their connection wirings are arranged on the long plate-shaped member, wherein the solar panel is arranged on the secondary battery. The water level measuring device according to any one of claims 1 to 6.

Images