Monitoring system, monitoring method, and monitoring program

Abstract

We provide a monitoring system to more effectively prevent cable theft and other related incidents. [Solution] In a monitoring system 100 for a cable inserted into a buried pipe, the monitoring system 100 comprises a plurality of tracking devices 200 installed at predetermined intervals on the cable and constituting a bus-type or star-type network, and a monitoring device 1000 located at the root of the network. The tracking device 200 comprises an antenna unit that emits omnidirectional radio waves and has a resonant frequency λ / 2 which is less than or equal to the diameter of the circular buried pipe or the length of the long side of the rectangular cross-section of the square buried pipe, and a relay communication unit 201 that receives identification information from other tracking devices 200 via the antenna unit and transmits the received identification information and its own identification information to perform relay communication from downstream to upstream, and the monitoring device 1000 comprises a generation unit 1002 that generates a network configuration based on the identification information acquired by the relay communication 201.

Description

Technical Field

[0001] The present invention relates to a monitoring system, a monitoring method, and a monitoring program.

Background Art

[0002] Conventionally, there has been a technology for preventing theft of solar cell modules in photovoltaic power generation.

[0003] For example, Patent Document 1 discloses a technology for tracking by wireless communication even when a solar cell module has been stolen.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The long cables used in power plants may be cut and partially stolen. However, the technology of Patent Document 1 does not assume that the cables are cut and partially stolen, so it is not suitable for preventing cable theft.

[0006] The present invention has been made in view of the above circumstances, and an object to be solved is to provide a new technology for cable monitoring to more appropriately prevent cable theft and the like.

Means for Solving the Problems

[0007] [1] A monitoring system for a cable inserted into an embedded pipe, The monitoring system includes a plurality of tracking devices installed at predetermined intervals on the cable and constituting a bus-type or star-type network, and a monitoring device located at the root of the network. The aforementioned tracking device is An antenna section that emits omnidirectional radio waves, having a resonant frequency such that λ / 2 is less than or equal to the diameter of a circular buried pipe or the length of the longer side of the rectangular cross-section of a square buried pipe, The system includes a relay communication unit that receives identification information from other tracking devices via the antenna unit and transmits the received identification information and its own identification information to perform relay communication from downstream to upstream. The aforementioned monitoring device is The system includes a generation unit that generates a network configuration based on the identification information obtained by the relay communication. Monitoring system.

[0008] [9] A monitoring method performed by a monitoring system for cables inserted into a buried pipe, The monitoring system comprises a plurality of tracking devices installed at predetermined intervals along the cable and constituting a bus-type or star-type network, and a monitoring device located at the root of the network. The aforementioned tracking device A radiation process in which omnidirectional radio waves are emitted at a resonant frequency where λ / 2 is less than or equal to the diameter of the circular buried pipe or the length of the longer side of the rectangular cross-section of the square buried pipe, The system includes a relay communication step that receives identification information from other tracking devices and transmits the received identification information and the identification information of the own device to perform relay communication from downstream to upstream. The aforementioned monitoring device The system includes a generation step of generating a network configuration based on the identification information obtained by the relay communication, Monitoring method.

[0009] This configuration allows for monitoring and managing the cables while reducing the attenuation of radio waves from tracking devices stored in the buried pipes along with the cables.

[0010] [2] The antenna section radiates circularly polarized waves, The monitoring system described in [1].

[0011] This configuration reduces the attenuation of radio waves from the tracking device.

[0012] [3] The tracking device is It has a vibration sensor, and a mode switching unit that transitions from free space mode to sleep mode when the vibration sensor does not detect vibration for a certain period of time, and transitions from sleep mode to free space mode when the vibration sensor detects vibration, The relay communication unit transmits its own identification information at regular intervals in the free space mode, and further transmits identification information at intervals longer than the transmission interval in the free space mode in the sleep mode, and further performs the relay communication at least in the sleep mode. The monitoring system described in [1] or [2].

[0013] This configuration allows for monitoring and managing cables while suppressing battery drain in the tracking device.

[0014] [4] The sleep mode comprises at least a first sleep mode and a second sleep mode, The mode switching unit transitions from the first sleep mode to the second sleep mode when it does not receive identification information from another tracking device for a certain period of time. The relay communication unit transmits identification information at intervals longer than the transmission interval of identification information in the first sleep mode during the second sleep mode. The monitoring system described in [3].

[0015] This configuration allows for the periodic transmission of identification information, while also suppressing battery depletion in the tracking device and enabling cable monitoring and management.

[0016] [5] When the mode switching unit does not receive the identification information from other tracking devices for a certain period of time, it transitions from the sleep mode to the submersion mode, and when the vibration sensor detects vibration, it transitions from the submersion mode to the free space mode. The relay communication unit transmits the identification information at intervals longer than the transmission of the identification information in the sleep mode in the submersion mode, and furthermore, does not perform the relay communication in the submersion mode. The monitoring system according to [3] or [4].

[0017] With such a configuration, it is possible to monitor and manage the cable while suppressing the decrease of the battery when the tracking device is submerged.

[0018] [6] The sleep mode has at least a first-stage sleep mode and a second-stage sleep mode. When the mode switching unit does not receive the identification information from other tracking devices for a certain period of time, it transitions from the sleep mode to the submersion mode, and when the vibration sensor detects vibration, it transitions from the submersion mode to the free space mode. The relay communication unit transmits the identification information at intervals longer than the transmission interval of the identification information in the first-stage sleep mode in the second-stage sleep mode, and furthermore, transmits the identification information at intervals longer than the transmission of the identification information in the sleep mode in the submersion mode, and furthermore, does not perform the relay communication in the submersion mode. The monitoring system according to [3].

[0019] With such a configuration, it is possible to transmit the identification information regularly, and furthermore, to monitor and manage the cable while suppressing the decrease of the battery when the tracking device is submerged.

[0020] [7] The relay communication unit transmits the relay count information that can determine which relay communication it is when transmitting the identification information of its own device and the identification information received from other tracking devices. The generation unit generates a network configuration including the installation order of the tracking device based on the identification information and the relay count information. A monitoring system as described in any of [1] to [6].

[0021] This configuration allows for the automatic generation of a network configuration that includes the sequence of tracking devices installed on buried cables.

[0022] [8] The antenna section has a configuration in which signals with a relative phase difference of 90 degrees are input to two feed points, or a configuration in which two corners opposite each other in the diagonal direction of a roughly rectangular patch are cut off. A monitoring system as described in any of [1] to [7].

[0023] This configuration makes it possible to create an antenna that emits circularly polarized radio waves. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a new technology for cable monitoring that can more effectively prevent cable theft and the like. [Brief explanation of the drawing]

[0025] [Figure 1] A block diagram showing the configuration of the anti-theft system in Embodiment 1. [Figure 2] Hardware configuration diagram in this embodiment. [Figure 3] A schematic diagram illustrating the cable management of a power plant in Embodiment 1. [Figure 4] A block diagram showing the functional components in Embodiment 1. [Figure 5] An example of the data configuration stored in the storage unit in Embodiment 1. [Figure 6] A flowchart for determining the presence or absence of a tracking device at a power plant in Embodiment 1. [Figure 7] An example of an embodiment of the tracking device according to the present invention. [Figure 8] An example of the installation of a tracking device adjacent to a cable according to the present invention. [Figure 9] A block diagram showing the configuration of the monitoring system in Embodiment 2. [Figure 10] A schematic diagram illustrating the cable management of a power plant in Embodiment 2. [Figure 11] An example of an antenna embodiment in Embodiment 2. [Figure 12] Flowchart of the network configuration generation process in Embodiment 2. [Figure 13] Flowchart of the mode transition process of the tracking device in Embodiment 2. [Figure 14] An example of a state transition diagram relating to the modes of the tracking device in Embodiment 2. [Modes for carrying out the invention]

[0026] The anti-theft system of the present invention will be described below with reference to the drawings. Preferred embodiments are shown in the drawings. However, the present invention can be carried out in many different forms and is not limited to the embodiments described herein.

[0027] For example, this embodiment describes the configuration and operation of the anti-theft system, but similar effects can be achieved by the method (steps) of execution, the apparatus, the computer program, etc. The program in this embodiment may be provided as a non-transient recording medium that can be read by a computer, or it may be provided so that it can be downloaded from an external server, or the program may be launched on an external computer in order for the client terminal to perform its functions (so-called cloud computing).

[0028] Furthermore, in this embodiment, "part" may include, for example, hardware resources implemented by a circuit in a broad sense, and information processing of software that can be specifically realized by these hardware resources. In this embodiment, "information" can be represented, for example, by the physical value of a signal value representing voltage or current, the high or low value of a signal value as a set of binary bits composed of 0s or 1s, or by a quantum superposition (so-called qubit), and communication and calculations can be performed on a circuit in a broad sense.

[0029] In a broad sense, a circuit is a circuit realized by appropriately combining circuits, circuits (including processors and memory). That is, it includes CPUs (Central Processing Units), GPUs (Graphics Processing Units), LSIs (Large Scale Integration), ASICs (Application Specific Integrated Circuits), FPGAs (Field-Programmable Gate Arrays), etc.

[0030] <System Overview in Embodiment 1> Figure 1 is a block diagram showing the configuration of the anti-theft system in Embodiment 1. As shown in Figure 1, the anti-theft system 0 comprises an anti-theft device 1, a tracking device 2, and a user terminal 3. The anti-theft device 1 is configured to communicate with the user terminal 3 via a network NW. The anti-theft device 1 operates as a server, and the user terminal 3 operates as a client terminal.

[0031] The anti-theft device 1 receives identification information, etc., from the tracking device 2. The anti-theft device 1 also determines whether or not the tracking device 2 is present at the power plant based on the received identification information, etc. Furthermore, the anti-theft device 1 notifies the user terminal 3 of the result of its determination.

[0032] The anti-theft device 1 can utilize general-purpose server computers or personal computers. It is also possible to configure the anti-theft device 1 using multiple computers. Furthermore, the anti-theft device 1 may also be a smartphone or tablet device.

[0033] Tracking device 2 is a device that transmits identification information (an identification number that uniquely identifies tracking device 2, such as a tracking device ID) and its own location information. The identification information transmitted by tracking device 2 is received by anti-theft device 1 and other tracking devices 2 that did not transmit the identification information. In addition, tracking device 2 periodically transmits its own location information (GPS information).

[0034] The tracking device 2 is an antenna, and could be a pattern antenna, chip antenna, patch antenna, etc. A pattern antenna is preferable for the tracking device 2 in order to transmit radio waves over long distances.

[0035] Tracking device 2 includes a Bluetooth® unit (chip or module), and the Bluetooth® unit transmits information. Tracking device 2 may also include a ZigBee® unit (chip or module), and the ZigBee® unit may transmit information.

[0036] Furthermore, the tracking device 2 may include a GPS(registered trademark) unit (chip or module), and the GPS(registered trademark) unit may transmit information. Also, the tracking device 2 may include an LTE(registered trademark) unit (chip or module), and the LTE(registered trademark) unit may transmit information.

[0037] User terminal 3 receives information from the anti-theft device 1 and the tracking device 2. User terminal 3 can be a smartphone, tablet, personal computer, or other terminal device. User terminal 3 may be one or multiple devices.

[0038] Multiple tracking devices 2 are installed in close proximity to cable 4 (a single long cable).

[0039] The anti-theft device 1 and / or user terminal 3 can emit a sound to the tracking device 2 via a specific input. For example, the tracking device 2 emits a sound in response to an instruction input from the anti-theft device 1 and / or user terminal 3. The ability of the anti-theft device 1 and / or user terminal 3 to emit a sound to the tracking device 2 proves that the tracking device 2 belongs to the person who is emitting that sound.

[0040] Furthermore, by receiving location information of the tracking device 2 from the anti-theft device 1 and / or user terminal 3, the location of the stolen tracking device 2 can be determined. Since the thief is likely to steal the tracking device 2 along with the cable 4 without realizing its presence, the location of the cable 4 thief can be determined from the location of the tracking device 2.

[0041] In this embodiment, the network NW is an IP (Internet Protocol) network, but there are no restrictions on the type of communication protocol, nor on the type or size of the network.

[0042] <Hardware Configuration> Figure 2 is a hardware configuration diagram. As shown in Figure 2(a), the information processing device 10 (anti-theft device 1, monitoring device 1000) has a control unit 101, a storage unit 102, and a communication unit 103, which are used to perform the functions of each unit and each process.

[0043] The control unit 101 includes one or more processors such as a CPU (Central Processing Unit), and controls the entire operation of the information processing device 10 by executing the anti-theft program, OS (Operating System), browser software, and other applications according to the present invention.

[0044] The storage unit 102 is an HDD (Hard Disk Drive), SSD (Solid State Drive), ROM (Read Only Memory), RAM (Random Access Memory), etc., and stores the anti-theft program according to the present invention and data used by the control unit 101 when executing processing based on the program. The control unit 101 executes processing based on the anti-theft program stored in the storage unit 102, thereby realizing the functional configuration described later.

[0045] The communication unit 103 performs communication control with the network NW and provides inputs necessary for operating the information processing device 10, as well as outputs related to the operation results.

[0046] As shown in Figure 2(b), the terminal device 9 (user terminal 3) has a control unit 91, a storage unit 92, a communication unit 93, an input unit 94, and an output unit 95, which are used to perform the functions of each unit and each process.

[0047] The control unit 91 of the terminal device 9 includes one or more processors such as a CPU and controls the entire operation process of the terminal device 9. The storage unit 92 of the terminal device 9 is an HDD, SSD, ROM, RAM, etc., and stores the above-mentioned application and data used by the control unit 91 when it executes processing based on the program.

[0048] The communication unit 93 of the terminal device 9 controls communication with the network NW. The input unit 94 of the terminal device 9 is a mouse, keyboard, etc., which inputs operation requests from the user / provider to the control unit 91. The output unit 95 of the terminal device 9 is a display, etc., which displays the results of processing by the control unit 91.

[0049] <Schematic diagram of Embodiment 1> Figure 3 is a schematic diagram of cable management in a power plant according to Embodiment 1. The power plant 5 has multiple cables 4, and tracking devices 2 (2a to 2u) are installed in close proximity to each cable 4. Furthermore, as shown in Figure 3, multiple tracking devices 2 are installed in close proximity to the cables at predetermined intervals.

[0050] Since thieves are likely to steal by cutting the cables at the power plant, installing the tracking device 2 close to the cable 4 at predetermined intervals, as shown in Figure 3, increases the likelihood that thieves will steal the tracking device 2 along with the cut cable 4.

[0051] Furthermore, the power plant 5 has an anti-theft device 1 to manage the theft of its multiple cables. The anti-theft device 1 uses information received from the tracking device 2 to determine whether the tracking device 2 has been stolen along with the cable 4. Since the range in which the tracking device 2 can transmit information is limited, if the tracking device 2 is taken to a location far from the anti-theft device 1 (for example, outside the power plant), information from the tracking device 2 will cease.

[0052] Since thieves are likely to steal the tracking device 2 along with the severed cable 4, the anti-theft device 1 can determine if the cable 4 has been stolen by determining whether the reception of information from a certain tracking device 2 has been interrupted.

[0053] When cable 4 (the cable on which tracking device 2 is installed) leaves power plant 5, terminals such as smartphones located on the infrastructure network outside of power plant 5 play the role of uploading (transmitting) the identification information and / or transfer identification information of tracking device 2 onto the cloud network.

[0054] Specifically, tracking device 2 transmits its own identification information, which is received by a terminal such as a smartphone on the infrastructure network. The smartphone then adds location information and uploads (transmits) this information (identification information, transfer identification information, location information, etc.) to the cloud network.

[0055] If a smartphone on the network has downloaded a dedicated app or program, it may receive information transmitted by tracking device 2. Furthermore, even if a smartphone on the network has not downloaded a dedicated app or program, it may still receive information transmitted by tracking device 2.

[0056] In this way, no matter where the tracking device 2, which is installed on the stolen cable, moves within Japan, its location can be tracked using the location information of a smartphone or other device near the tracking device 2.

[0057] The anti-theft device 1 receives information (identification information, transfer identification information, location information, etc.) transmitted by a terminal such as a smartphone on the infrastructure network. The notification unit 13 may also transmit this information to the user terminal 3. In this way, the owner of the user terminal 3 can track the location of the tracking device 2.

[0058] Tracking device 2 transmits its own identification information and also forwards identification information received from other tracking devices as forwarded identification information. Tracking device 2 transmits the identification information and / or forwarded identification information periodically (for example, once every predetermined time).

[0059] Information transmitted by tracking device 2 is received by other tracking devices 2 located within the range of that information. For example, information transmitted by tracking device 2a may be received by tracking devices 2h or 2o installed on other cables.

[0060] Tracking device 2 may receive information only from adjacent tracking devices 2 installed on the same cable. For example, tracking device 2 may receive information only from tracking devices 2 that are further away from the anti-theft device 1 than itself (for example, if tracking device 2b is the tracking device 2a).

[0061] In addition, tracking device 2 may receive information from other tracking devices 2 that are not located next to it but are installed on the same cable. For example, tracking device 2d may receive information from tracking device 2a.

[0062] In this embodiment, the power plant is a solar power plant. The cables (electric wires) of a solar power plant are made of copper wire or the like, which can be sold for a high price, and are therefore often stolen. To prevent theft, a tracking device 2 is installed close to the cable 4.

[0063] <Functional Components> As shown in Figure 4, the anti-theft device 1 comprises a receiving unit 11, a determination unit 12, a notification unit 13, and a storage unit 14.

[0064] The arrangement of these functional components is merely an example, and it is also possible to implement these functional components on multiple computers to constitute the anti-theft system 0. For example, some of the functional components of the anti-theft device 1 may be arranged on one or more devices configured to communicate with the tracking device 2, user terminal 3, and the anti-theft device 1. Similarly, some of the functional components of the tracking device 2 may be arranged on one or more devices configured to communicate with the anti-theft device 1, user terminal 3, and the tracking device 2. Furthermore, some of the functional components of the user terminal 3 may be arranged on one or more devices configured to communicate with the anti-theft device 1, tracking device 2, and user terminal 3.

[0065] <Data structure in Embodiment 1> Figure 5 shows an example of the data configuration stored in the memory unit in Embodiment 1. The memory unit 14 of the anti-theft device 1 stores power plant information, cable information, tracking device information, etc.

[0066] The arrangement of each data is merely an example, and some or all of the data stored in the memory unit of the anti-theft device 1 may be stored in one or more devices configured to communicate with the tracking device 2, the user terminal 3, and the anti-theft device 1. Similarly, some or all of the data stored in the memory unit of the tracking device 2 may be stored in one or more devices configured to communicate with the anti-theft device 1, the user terminal 3, and the tracking device 2. Furthermore, some or all of the data stored in the memory unit of the user terminal 3 may be stored in one or more devices configured to communicate with the anti-theft device 1, the tracking device 2, and the user terminal 3.

[0067] Power plant information is information about a power plant and is managed by a power plant ID, as shown in Figure 5(a). Power plant information includes the power plant name and address, as shown in Figure 5(a). Power plant information may also include the cable ID of the cable 4 used at the power plant and the tracking device ID of the tracking device 2. In addition, if the power plant is divided into areas, the power plant information may also include information about those areas.

[0068] Cable information refers to information about cables used in a power plant and is managed by a cable ID, as shown in Figure 5(b). Cable information includes the power plant ID in which the cable is used. If the power plant is divided into areas, the cable information may also include information about the area in which the cable is used.

[0069] Tracking device information refers to information about tracking devices installed in close proximity to a cable, and is managed by a tracking device ID, as shown in Figure 5(c). The tracking device information includes the cable ID on which the tracking device is installed. Furthermore, if a tracking device to which identification information is transmitted is predetermined for each tracking device, the tracking device information may also include the ID of the destination tracking device. Furthermore, if a tracking device to which identification information is received is predetermined for each tracking device, the tracking device information may also include the ID of the receiving tracking device.

[0070] <Flowchart of the process in Embodiment 1> Figure 6 is a flowchart of the process for determining whether or not a tracking device is present at a power plant in Embodiment 1.

[0071] <Register various types of information> In step S601, the administrator or other person responsible for managing cable 4 of power plant 5 registers various information (Figures 5(a) to (c)), such as information regarding the tracking device installed on cable 4, in advance.

[0072] <Receiving identification information, etc.> In step S602, the receiving unit 11 receives identification information from the tracking device 2 to identify the tracking device 2 (an identification number that uniquely identifies the tracking device 2, such as a tracking device ID). The tracking device 2 transmits identification information to identify itself. The tracking device 2 may transmit identification information periodically.

[0073] The receiving unit 11 receives the identification information and transfer identification information transmitted by the tracking device 2. The tracking device 2 transfers the identification information received from other tracking devices 2 as transfer identification information. The tracking device 2 transfers the transfer identification information to other tracking devices 2 and / or the anti-theft device 1.

[0074] If tracking device 2 is in close proximity to the cable, the current flowing through the copper wire will prevent the radio waves from traveling far, thus limiting the range over which information can be transmitted.

[0075] Therefore, as shown in Figure 3, if there is only one anti-theft device 1 at the power plant 5, the receiving unit 11 may not be able to receive identification information transmitted by the tracking device 2, which is far from the anti-theft device 1. For example, in Figure 3, the receiving unit 11 may only receive identification information transmitted by tracking devices 2g, 2n, 2u, etc., which are close to the anti-theft device 1.

[0076] Tracking devices 2 are installed at predetermined intervals (intervals that allow information to be transmitted to other tracking devices 2). For example, other tracking devices 2 are installed within range of tracking device 2 to which information can be transmitted. This ensures that even if the anti-theft device 1 cannot receive the information transmitted by tracking device 2, other tracking devices 2 can receive the transmitted identification information and / or transfer identification information.

[0077] For example, in Figure 3, tracking device 2a transmits its own identification information to tracking device 2b. Furthermore, tracking device 2b transmits its own identification information to tracking device 2c and transmits the identification information received from tracking device 2a to tracking device 2c as transfer identification information. Then, tracking device 2c transmits its own identification information to tracking device 2d and transmits the transfer identification information received from tracking device 2b (identification information of tracking devices 2a and 2b) to tracking device 2d.

[0078] By repeating this process, the identification information of tracking devices 2a to 2f is transmitted to tracking device 2g, which is capable of transmitting information to the anti-theft device 1, and the receiving unit 11 can receive the identification information of tracking devices 2a to 2g.

[0079] Tracking device 2 transmits identification information and / or transfer identification information to other tracking devices 2 installed on the same cable 4. Tracking device 2 may also transmit identification information and / or transfer identification information to other tracking devices 2 within range of information transmission. For example, in Figure 3, tracking device 2a may transmit its own identification information to tracking device 2h, etc.

[0080] Tracking device 2 may receive identification information and / or transfer identification information from a predetermined tracking device 2, or may transmit identification information and / or transfer identification information to a predetermined tracking device 2. In addition, tracking device 2 may receive all identification information and / or transfer identification information transmitted by other tracking devices 2, and transmit all the information it has received.

[0081] The receiving unit 11 receives identification information and / or transfer identification information from a specific tracking device 2. For example, the receiving unit 11 receives identification information and / or transfer identification information from a tracking device 2 capable of transmitting information to the anti-theft device 1. In addition, the receiving unit 11 may receive identification information and / or transfer identification information from a predetermined tracking device 2.

[0082] <Determination of Identification Information> In step S603, the determination unit 12 determines the identification information stored in the storage unit 14, the identification information received by the receiving unit 11, and the transfer identification information received by the receiving unit 11. The storage unit 14 pre-stores the identification information of the tracking device 2 located in the power plant 5 (for example, the tracking device ID).

[0083] Based on this, the determination unit 12 determines whether all tracking devices 2 are present at the power plant 5 by comparing the identification information stored in the memory unit 14, the identification information received by the receiving unit 11, and the transfer identification information received by the receiving unit 11. In other words, the determination unit 12 determines whether all identification information stored in the memory unit 14 has been received and whether all tracking devices 2 are present at the power plant 5.

[0084] <Notification of the result> In step S604, the notification unit 13 notifies the result of the determination unit 12's determination. The notification unit 13 may also notify identification information that has not been received. For example, by having the storage unit 14 associate the identification information of the tracking device 2 with the location of the tracking device 2 at the power plant and / or the location of the cable on which the tracking device 2 is installed (for example, the distance in the cable from the anti-theft device 1), the notification unit 13 can notify the location of the stolen tracking device 2.

[0085] In addition, the notification unit 13 may display a construction drawing of the power plant 5 (for example, a drawing that visualizes the locations of the tracking device 2 and cable 4 in the power plant, as shown in Figure 3), and visualize and display which tracking device has not received identification information from that construction drawing. In this way, it is possible to visualize which tracking device 2 has been stolen at the power plant.

[0086] The notification unit 13 notifies the user terminal 3 that it has not received all the identification information stored in the storage unit 14. By storing the contact information (email address, etc.) of the recipient of the notification in the storage unit 14, the notification unit 13 can notify that contact. For example, the notification unit 13 notifies the user terminal 3 that the cable 4 may have been stolen along with the tracking device 2.

[0087] <Example of two embodiments of the tracking device> Figure 7 shows an example of an embodiment of the tracking device according to the present invention. To transmit identification information and location information over long distances, it is preferable for the tracking device 2 to be large. On the other hand, if the tracking device 2 is large, the likelihood of a thief noticing its presence increases. By making the shape of the tracking device 2 elongated, it can be made less likely for a thief to notice it even when it is close to the cable 4.

[0088] Figure 7(a) is a front view of an embodiment of the tracking device 2. The tracking device 2 in Figure 7(a) is a patch antenna and consists of a substrate (including dielectric) P71, copper foil (copper part for frequency adjustment) P72, and impedance adjustment section P73. The substrate P71 is rectangular and consists of two pairs of opposing sides, with the lengths of the non-opposing sides being different. By making one of the two pairs of opposing sides longer and the other shorter, it can be made less conspicuous when installed on a cable.

[0089] The impedance adjustment section adjusts the impedance to prevent the resonance point of the tracking device from being disrupted. This enables stable characteristics of the tracking device 2, which are less susceptible to external factors.

[0090] The length of the substrate P71 in Figure 7(a) is, for example, λ / 2 in the longitudinal direction and λ / 8 in the transverse direction. The length of the substrate P71 in Figure 7(a) is not limited to this. Preferably, the length of the substrate P71 in Figure 7(a) is λ / (4 × √(ε0)) (ε0: dielectric constant) in the longitudinal direction and 10 to 20 millimeters in the transverse direction. Preferably, the length in the longitudinal direction is at least twice the length in the transverse direction.

[0091] Furthermore, the thickness of the substrate P71 in Figure 7(a) is λ / 51 or λ / 38. The thickness of the substrate P71 in Figure 7(a) is not limited to these. The thickness of the substrate P71 in Figure 7(a) is preferably λ / 245 to λ / 24 millimeters. The tracking device 2 in Figure 7(a) is a flattened rectangle (flattened rectangular plate). λ is the wavelength of the antenna used, and the optimal length and thickness vary depending on λ.

[0092] The tracking device 2 shown in Figure 7(a) exhibits minimal change in radiation characteristics even when equipped with multiple power supply units (e.g., two button batteries). Furthermore, the tracking device 2 shown in Figure 7(a) exhibits minimal change in radiation characteristics even when installed in close proximity to the sheath (cover) of an electric wire (copper wire). Moreover, the tracking device 2 shown in Figure 7(a) exhibits minimal change in radiation characteristics even when equipped with high-frequency electronic circuits on its rear surface.

[0093] The circuit board P71 may consist of one layer (one sheet) or multiple layers (for example, 2 to 5 layers). Furthermore, the tracking device 2 may include a battery (for example, a button battery). The number of batteries included in the tracking device 2 is not limited and may be one or multiple (for example, 2 to 5). Furthermore, the tracking device 2 may be equipped with a high-frequency electronic circuit (for example, an RF-ID circuit) on its back.

[0094] Figure 8 shows an example of the installation of a tracking device adjacent to a cable according to the present invention. Figure 8 is a cross-sectional view of the cable 4. The cable 4 is composed of multiple copper wires (electric wires) 6 and a sheath (cover) to bundle them together.

[0095] In a solar power plant, as shown in Figure 8, multiple cables (for example, three) are laid together. The tracking device 2 only needs to be close to the cables 4, and various installation methods are possible. For example, the tracking device 2 can be installed between multiple cables (for example, two), as shown in Figures 8(a) to (e). If the tracking device 2 is installed (from the outside) after the cables 4 have been installed, the installation method shown in Figures 8(a) to (e) is considered appropriate. This simplifies the installation after the cables 4 have been installed.

[0096] Alternatively, the tracking device 2 may be installed sandwiched between two cables 4, as shown in Figures 8(f) and (g). This reduces the likelihood that a thief will notice the tracking device 2.

[0097] Alternatively, for example, the tracking device 2 may be installed in the center of the three cables 4, as shown in Figures 8(h) and (i). This reduces the likelihood that a thief will notice the tracking device 2.

[0098] The tracking device 2 in Figures 8(a) and (b) represents the side view of the tracking device 2 as seen from the direction of the arrow in Figure 7(a). The shape of the side view as seen from the direction of the arrow in Figure 7(a) is not limited and may be a side view like that of the tracking device 2 in Figures 8(c) to (e) (for example, a circle, ellipse, triangle, etc.).

[0099] The tracking device 2 is secured with tape (for example, waterproof tape) or string of the same color as the cable 4.

[0100] The tracking device 2 can be any shape. Making the tracking device 2 long and slender as shown in Figure 7(a) reduces the likelihood of a thief noticing the tracking device 2 installed on the cable 4. A long and slender tracking device 2 is easier to install close to the cable 4. Furthermore, a long and slender tracking device 2 is easier to secure to the cable 4 with tape or the like.

[0101] <Monitoring system in Embodiment 2> Embodiment 2 differs from Embodiment 1 in that the cable is buried underground. The buried conduit is through which the cable is inserted and buried underground. The buried conduit may be a bellows-shaped pipe or the like, and the material may be resin or concrete. Alternatively, the buried conduit may be a metal pipe.

[0102] Figure 9 is a block diagram showing the configuration of the monitoring system in Embodiment 2. As shown in Figure 9, the monitoring system 100 comprises a monitoring device 1000, a tracking device 200, and a user terminal 3.

[0103] The monitoring device 1000 receives identification information, etc., from the tracking device 200. Based on the information received from the tracking device 200, the monitoring device 1000 generates a network configuration (the configuration of the positions and order (arrangement) of each tracking device 200 installed on the cable) and displays the network configuration on the user terminal. The monitoring device 1000 may also display a construction diagram of the power plant cable, including the network configuration of the tracking devices 200.

[0104] The monitoring device 1000 displays the location information and network configuration of the tracking device 200 on the user terminal 3. The monitoring device 1000 may also include the same configuration as the anti-theft device 1, and may have the same functions and perform the same processing.

[0105] Tracking device 200 is a device that transmits identification information (an identification number that uniquely identifies tracking device 2, such as a tracking device ID) and its own location information. The identification information transmitted by tracking device 200 is received by monitoring device 1000 and other tracking devices 200 other than the tracking device 200 that transmitted the identification information. Tracking device 200 may include the same configuration as tracking device 2, and may have the same functions and perform the same processing.

[0106] <Schematic diagram of Embodiment 2> Figure 10 is a schematic diagram of cable management in a power plant according to Embodiment 2. The power plant has multiple cables C1, C2, ..., and tracking devices 200 (200a to 200j) are installed in close proximity to each cable. Furthermore, as shown in Figure 10, multiple tracking devices 200 are installed in close proximity to the cables at predetermined intervals.

[0107] Multiple tracking devices 200 form a bus-type or star-type network. The tracking devices 200 perform relay communication with other tracking devices installed on the same cable, as described later.

[0108] For example, tracking devices 200a to 200e installed on cable C1 communicate via relay amongst themselves, but do not communicate via relay with tracking devices 200f to 200j installed on cable C2. Because each cable is housed in a buried conduit and buried underground, tracking devices installed on different cables do not communicate with each other.

[0109] The tracking device 200 transmits the information it receives (e.g., identification information) via relay communication to the monitoring device 1000 located at the root of the network. Specifically, the tracking device 200, which is installed at the end of the cable and close to the monitoring device 1000, transmits the information to the monitoring device 1000.

[0110] Furthermore, the power plant cables C1, C2, ... are stored in buried pipes P1, P2, ... respectively and buried underground. The tracking device 200, which is close to the cables inserted into the buried pipes, is also stored in the buried pipes together with the cables and buried underground.

[0111] The buried pipe may be circular or rectangular. The cross-section of the buried pipe may not be circular or rectangular. Cables C1 and C2 may consist of a single cable or multiple cables (for example, three cables).

[0112] <Functional Components> As shown in Figure 9, the monitoring device 1000 comprises a receiving unit 1001, a generation unit 1002, a display processing unit 1003, and a storage unit 1004. The arrangement of these functional components is an example, and it is also possible to implement these functional components in multiple computers to constitute the monitoring system 100. For example, some of the functional components of the monitoring device 1000 may be arranged in the tracking device 200, the user terminal 3, and one or more devices configured to communicate with the monitoring device 1000.

[0113] The tracking device 200 includes a relay communication unit 2021, a mode switching unit 202, and a vibration detection unit 203. Furthermore, the tracking device 200 includes an antenna unit that emits omnidirectional radio waves. The antenna unit may emit linearly polarized waves or circularly polarized waves.

[0114] By radiating circularly polarized waves from the antenna section, several advantages are available, including improved diffraction characteristics (circular polarization has less attenuation than linear polarization because its phase rotates with time), improved scattering characteristics (circular polarization has less radiation loss due to scattering even when it hits an outer wall), improved propagation loss (the difference within a metal tube of a specified size remains unchanged), improved attenuation characteristics (circular and linear polarization are equivalent), improved polarization effect (bend characteristics) (circular polarization has good bending characteristics due to the change caused by rotation with time), and improved frequency characteristics (in the 2400MHz band, they are equivalent due to strong directivity). Therefore, since circular polarization is more advantageous than linear polarization in terms of usage conditions, it is advisable to use circular polarization.

[0115] <Example of an antenna embodiment in Embodiment 2> Figure 11 shows a typical patch antenna and an example of an antenna embodiment in Embodiment 2. Figure 11(a) is a typical patch antenna, and Figure 11(b) is an example of an antenna embodiment in Embodiment 2.

[0116] By making the lengths W and L of patch Pa in Figure 11(a) the same, an omnidirectional antenna can be realized. Furthermore, as shown in Figure 11(b), by cutting off two corners opposite each other in the direction of the opposing line of a roughly rectangular patch (the roughly rectangular portion enclosed by the dashed line), an antenna that radiates circular polarization can be realized.

[0117] In addition, an antenna that radiates circular polarization can be realized by changing the phase of the pattern length by 90 degrees, or by shifting the feed point by 90 degrees (configuring the antenna to input signals with a relative phase difference of 90 degrees to the two feed points). For example, as shown in Figure 11(c), an antenna that radiates circular polarization can be realized by shifting the feed point by 90 degrees (λ / 4).

[0118] The resonant frequency of an antenna is manufactured to match λ / 2 of the operating frequency. Since λ is calculated from the speed of light (a constant) and the frequency, the resonant frequency of the antenna is calculated from the speed of light and the operating frequency of the antenna.

[0119] For example, the operating frequency of an antenna could be 2400MHz to 2500MHz. Buried pipes can be considered as metal pipes. Therefore, the diameter of a circular buried pipe or the length of the longer side of the rectangular cross-section of a square buried pipe must be greater than or equal to the wavelength λ / 2 of the operating frequency. Thus, the resonant frequency must be such that λ / 2 is less than or equal to the diameter of the circular buried pipe or the length of the longer side of the rectangular cross-section of a square buried pipe.

[0120] The attenuation of radio waves can be reduced by ensuring that the diameter of a circular buried pipe or the length of the longest side of the rectangular cross-section of a square buried pipe is greater than λ / 2. For example, if the antenna's operating frequency is 2400MHz, the diameter of the circular buried pipe or the length of the longest side of the rectangular cross-section of a square buried pipe should be 62.5mm or more. If the antenna's operating frequency is 2500MHz, the diameter of the circular buried pipe or the length of the longest side of the rectangular cross-section of a square buried pipe should be 60.0mm or more.

[0121] <Flowchart for generating network configuration> Figure 12 is a flowchart of the network configuration generation process in Embodiment 2.

[0122] <Start of relay communication> In step S1201, the relay communication unit 201 of the starting tracking device 200 (starting node) transmits its own identification information. The relay communication unit 201 of the tracking device 200 installed at the end of the cable starts transmitting its own identification information. For example, when the power to the tracking device 200 is turned on, the relay communication unit 201 starts transmitting.

[0123] The relay communication unit 201 may start relay communication after all tracking devices 200 have been installed on the cable, or after the tracking devices 200 have been powered on. The tracking devices 200 have vibration sensors, and for example, if the vibration sensors do not detect vibration for a certain period of time, the relay communication unit 201 may start relay communication. While the tracking devices 200 are being installed on the cable, they are subjected to artificial vibrations due to the installation work, but after installation is complete, they are buried underground and therefore the vibrations disappear.

[0124] The relay communication unit 201 of the starting tracking device 200 transmits its own identification information along with information indicating that it is the starting node. For example, the relay communication unit 201 of the starting tracking device 200 transmits its own identification information associated with HopTrace[0] (information indicating that it is the starting node).

[0125] The tracking device 200 that initiates the transmission of identification information is the one of the two tracking devices 200 installed at the end of the cable that is furthest from the monitoring device 1000. The position furthest from the monitoring device 1000 at the end of the cable is referred to as downstream, and the position closer to the monitoring device 1000 at the end of the cable is referred to as upstream.

[0126] In Figure 10, tracking devices 200a and 200f are the starting point tracking devices (starting nodes) in cables C1 and C2, respectively, and are downstream tracking devices. Tracking devices 200e and 200j are upstream tracking devices. For example, tracking device 200b is a tracking device 200 that is downstream of tracking devices 200c and 200d.

[0127] <Implementation of relay communication>< In step S1202, the relay communication unit 201 of the tracking device 200 (relay node) that has received identification information from another tracking device 200 transmits its own identification information along with the received identification information. When the relay communication unit 201 transmits its own identification information and the identification information received from the other tracking device 200, it also transmits relay count information that allows it to determine how many relay communications it has performed.

[0128] The relay communication unit 201 receives identification information from other tracking devices 200 via the antenna unit and transmits the received identification information and its own identification information, thereby performing relay (hopping) communication from downstream to upstream. The relay communication unit 201 of the tracking device 200 receives identification information from tracking devices 200 downstream of its own.

[0129] For example, the tracking device 200 may be installed at a distance such that it can communicate only with the adjacent tracking device 200. In this way, the relay communication unit 201 can relay communication only the information received from the adjacent tracking device 200.

[0130] For example, the relay communication unit 201 does not relay information containing its own identification information. In this way, the relay communication unit 201 does not relay information received from upstream.

[0131] Alternatively, for example, the relay communication unit 201 may relay the information with the largest data volume among the received information. In this way, the relay communication unit 201 can relay only the information received from the adjacent tracking device 200.

[0132] When the relay communication unit 201 of the tracking device 200 receives identification information from another tracking device 200, it transmits all of the identification information received from the other tracking device 200 (transmitting the identification information for each received HopTrace[n] (n=0, 1, 2, ...)).

[0133] When the relay communication unit 201 of the tracking device 200 receives identification information from another tracking device 200, it transmits its own identification information linked to HopTrace[n+1] (relay count information that can determine which relay communication it is (information indicating which relay node the device is)).

[0134] In addition, the relay communication unit 201 of the tracking device 200 may be pre-configured to perform relay communication when it receives identification information from a tracking device 200 downstream of itself (for example, each tracking device may be configured to perform relay communication when it receives information containing specific identification information).

[0135] The relay communication unit 201 of the tracking device 200, which is installed at the end of the cable and close to the monitoring device 1000, transmits information to the monitoring device 1000.

[0136] <Generating Network Configuration> In step S1203, the generation unit 1002 of the monitoring device 1000 generates a network configuration based on the identification information obtained by relay communication. The receiving unit 1001 of the monitoring device 1000 receives information (e.g., identification information, relay count information, etc.) from the tracking device 200 via relay communication and stores it in the storage unit 1004. Furthermore, the generation unit 1002 generates a network configuration including the installation order of the tracking device 200 (e.g., installation order from downstream on the cable, etc.) based on the identification information and relay count information obtained by relay communication.

[0137] The generation unit 1002 generates a network configuration (for example, a configuration showing which identification information tracking devices are installed on the cable and in what order) based on the identification information received by the receiving unit 1001, information indicating that it is the starting node, and information indicating which relay node it is.

[0138] The display processing unit 1003 processes the network configuration generated by the generation unit 1002 for display. The display processing unit 1003 may also display a diagram of the power plant's cable layout, including the identification information of the tracking device 200 and the arrangement order on the cable, on the user terminal 3 as the network configuration.

[0139] <Flowchart of mode transition processing for tracking device> Figure 13 is a flowchart of the mode transition process of the tracking device in Embodiment 2.

[0140] <Transition from free space mode to sleep mode> In step S1301, the mode switching unit 202 of the tracking device 200 has a vibration sensor, and transitions from free-space mode to sleep mode if the vibration sensor does not detect vibration for a certain period of time. Also, the mode switching unit 202 transitions from sleep mode to free-space mode if the vibration sensor detects vibration.

[0141] In free-space mode, the relay communication unit 201 transmits beacon information at predetermined (constant) intervals (for example, every second) (for example, by transmitting a signal within a range of several meters to tens of meters in wireless radius). Even in free-space mode, the tracking device 200 may receive information.

[0142] In free-space mode, the tracking device 200 transmits its own identification information to an unspecified number of smartphones, etc., and the identification information transmitted by the tracking device 200 is received by terminals such as smartphones on the infrastructure network, and those smartphones add location information and upload (transmit) that information (e.g., identification information, location information, etc.) to the cloud network.

[0143] In this way, if a cable to which the tracking device 200 is installed is stolen, the location of the cable can be identified based on the location information uploaded by a smartphone or other device that receives the identification information of the tracking device 200.

[0144] Therefore, when the tracking device 200 is buried underground and has not been stolen, it does not need to be in free-space mode, and the mode switching unit 202 transitions the tracking device 200 itself to sleep mode. When the tracking device 200 is buried underground, it is basically not subjected to vibration. Therefore, the mode switching unit 202 transitions from free-space mode to sleep mode when the vibration sensor does not detect vibration for a certain period of time.

[0145] On the other hand, if the cable is stolen, the tracking device 200 will be subjected to vibration, so the mode switching unit 202 will transition from sleep mode to free space mode when the vibration sensor detects vibration.

[0146] If the tracking device 200 is buried underground, it will not be affected by vibrations in principle. However, if an earthquake occurs, it may be affected by vibrations, and the vibration sensor may detect them. Therefore, the tracking device 200 needs to determine whether the vibrations detected by the vibration sensor are due to human movement (vibrations caused by the theft of the cable) or vibrations caused by an earthquake.

[0147] The vibration determination unit 203 of the tracking device 200 determines, based on acceleration and the number of vibrations, whether the vibration is caused by human movement or by an earthquake. If the vibration is caused by human movement, it is possible that the tracking device 200 will be subjected to multiple vibrations that continue for several minutes.

[0148] Therefore, the vibration determination unit 203 determines that the vibration is caused by human movement if the vibration sensor detects multiple vibrations (for example, a predetermined number of times) over a period of several minutes (for example, a predetermined time). The mode switching unit 202 may transition from sleep mode to free space mode based on the determination result of the vibration determination unit 203.

[0149] <Start of relay communication> In step S1302, the relay communication unit 201 performs relay communication when the tracking device 200 is in sleep mode. The relay communication unit 201 transmits its own identification information at regular intervals in free space mode, and further transmits identification information at intervals longer than the transmission interval in free space mode in sleep mode, and further performs relay communication at least in sleep mode.

[0150] The relay communication unit 201 transmits its own identification information at regular (determined) intervals (for example, every second) in free space mode, and transmits identification information at longer intervals than the transmission interval in free space mode (for example, every 10 minutes, every minute, every hour, every 4 hours, etc.).

[0151] When the tracking device 200 is in sleep mode, it transmits identification information at longer intervals than the transmission interval in free-space mode. Therefore, keeping the tracking device 200 in sleep mode consumes less battery power than keeping it in free-space mode.

[0152] <Radio wave reception determination> In step S1303, the relay communication unit 201 determines whether it has received identification information from another tracking device via the antenna unit. Tracking devices 200 installed on cables buried underground are often submerged in water. If submerged, the relay communication unit 201 cannot receive radio waves.

[0153] Even when submerged in water, transmitting radio waves for relay communication will consume the battery of the tracking device 200. When the tracking device 200 is submerged in water, battery consumption can be reduced by increasing the interval between transmissions of identification information by the relay communication unit 201.

[0154] <Transition from sleep mode to submersion mode> If the relay communication unit 201 does not receive identification information (radio waves) from the other tracking device 200 for a certain period of time (step S1303: Yes), in step S1304, the mode switching unit 202 transitions from sleep mode to submersion mode. For example, if the relay communication unit 201 has not received identification information from the other tracking device 200 a predetermined number of times (for example, if it has not received radio waves 6 times), the mode switching unit 202 transitions from sleep mode to submersion mode.

[0155] The relay communication unit 201 transmits identification information in submersion mode at longer intervals than when transmitting identification information in sleep mode (for example, at longer time intervals than when in sleep mode, such as every 6 hours, or at daily intervals, such as every day). Furthermore, the relay communication unit 201 may or may not perform relay communication in submersion mode.

[0156] The mode switching unit 202 transitions from submerged mode to free-space mode when the vibration sensor detects vibration (for example, man-made vibration or vibration caused by an earthquake). If the vibration determination unit 203 determines that the vibration detected by the vibration sensor is man-made, the mode switching unit 202 transitions the tracking device 200 from submerged mode to free-space mode.

[0157] Once the tracking device 200 has entered submersion mode, it will not transition from submersion mode to another mode (e.g., free space mode) unless the vibration sensor detects vibration. The tracking device 200 may also be configured to transition from submersion mode to another mode (e.g., free space mode) only when the vibration determination unit 203 determines that vibration is caused by an earthquake.

[0158] When the tracking device 200 is in submersion mode, it transmits identification information at longer intervals than in free-space mode or sleep mode. Therefore, keeping the tracking device 200 in submersion mode consumes less battery power than keeping it in free-space mode or sleep mode.

[0159] Furthermore, if the relay communication unit 201 is prevented from performing relay communication when the tracking device 200 is in submersion mode, the amount of data transmitted can be reduced, thereby conserving the battery power of the tracking device 200.

[0160] When the relay communication unit 201 performs relay communication in submersion mode, for example, the relay communication unit 201 may have a measurement sensor and relay the information measured by the measurement sensor. For example, the measurement sensor may acquire measurement data such as the battery level and temperature of the tracking device 200, and the relay communication unit 201 may relay the measurement data. The relay communication unit 201 may also relay the information measured by the measurement sensor in sleep mode.

[0161] The relay communication unit 201 transmits information such as the battery level of the tracking device 200 to the monitoring device 1000 via relay communication, and the display processing unit 1003 can then display the battery level of the tracking device 200 on the user terminal 3. In this way, the user can check the battery level of the tracking device 200.

[0162] If the relay communication unit 201 periodically receives identification information from another tracking device 200 (step S1303: No), in step S1304, the mode switching unit 202 transitions from sleep mode to free space mode.

[0163] <State transition diagram of the tracking device modes in Embodiment 2> Figure 14 is an example of a state transition diagram relating to the modes of the tracking device in Embodiment 2.

[0164] The sleep mode may have multiple stages (for example, two or three stages), and it is conceivable that there may be three sleep modes, as shown in Figure 14. The mode switching unit 202 transitions from the first sleep mode (sleep mode 1 in Figure 14) to the second sleep mode (sleep mode 2 in Figure 14) if it does not receive identification information from another tracking device 200 for a certain period of time in the first sleep mode (sleep mode 1 in Figure 14).

[0165] The relay communication unit 201 transmits identification information at longer intervals than the transmission interval for identification information in the first sleep mode during the second sleep mode. For example, the relay communication unit 201 transmits identification information every 10 minutes in sleep mode 1 and every hour in sleep mode 2.

[0166] The mode switching unit 202 transitions from the second sleep mode (sleep mode 2 in Figure 14) to the third sleep mode (sleep mode 3 in Figure 14) if it does not receive identification information from another tracking device 200 for a certain period of time in the second sleep mode (sleep mode 2 in Figure 14).

[0167] The relay communication unit 201 transmits identification information at longer intervals than the transmission interval for identification information in the second sleep mode during the third sleep mode. For example, the relay communication unit 201 transmits identification information every hour in sleep mode 2 and every four hours in sleep mode 3.

[0168] In sleep mode, the mode switching unit 202 transitions to free-space mode when the relay communication unit 201 receives identification information (radio waves) from another tracking device 200 via the antenna unit. Also, in sleep mode, if the vibration determination unit 203 determines that the vibration detected by the vibration sensor is artificial, the mode switching unit 202 transitions the tracking device 200 from sleep mode to free-space mode.

[0169] Furthermore, in submersion mode, if the vibration determination unit 203 determines that the vibration detected by the vibration sensor is artificial, the mode switching unit 202 may transition the tracking device 200 from submersion mode to free space mode.

[0170] In sleep mode or submersion mode, if the vibration determination unit 203 determines that the vibration detected by the vibration sensor is an earthquake vibration (seismic wave), the mode switching unit 202 transitions the tracking device 200 back to its original mode (sleep mode or submersion mode).

[0171] For example, if the vibration detection unit 203 determines that the vibration detected by the vibration sensor is an earthquake vibration (seismic wave) while in sleep mode 1, the mode switching unit 202 returns the tracking device 200 to sleep mode 1.

[0172] In addition, the mode switching unit 202 may be configured to transition from sleep mode or submersion mode to free space mode when the vibration sensor detects vibration (for example, artificial vibration or vibration caused by an earthquake) in sleep mode or submersion mode.

[0173] As described above, the configuration of the present invention provides a new technology for cable monitoring that can more effectively prevent cable theft and the like. [Explanation of symbols]

[0174] 0 Anti-theft system 1. Anti-theft device 11 Receiving unit 12 Judgment section 13 Notification Department 14 Storage section 2. Tracking device 3. User terminals 4 Cables 100 monitoring systems 1000 monitoring devices 1001 Receiver 1002 Generation part 1003 Display Processing Unit 1004 Storage section 200 tracking devices 201 Relay Communications Unit 202 Mode switching section 203 Vibration determination section C1 Cable C2 Cable NW Network

Claims

1. A monitoring system for cables inserted into buried pipes, The monitoring system comprises a plurality of tracking devices installed at predetermined intervals along the cable and constituting a bus-type or star-type network, and a monitoring device located at the root of the network. The aforementioned tracking device is An antenna section that emits omnidirectional radio waves, having a resonant frequency such that λ / 2 is less than or equal to the diameter of a circular buried pipe or the length of the longer side of the rectangular cross-section of a square buried pipe, The system includes a relay communication unit that receives identification information from other tracking devices via the antenna unit and transmits the received identification information and its own identification information to perform relay communication from downstream to upstream. The aforementioned monitoring device is The system includes a generation unit that generates a network configuration based on the identification information obtained by the relay communication. Monitoring system.

2. The aforementioned antenna section radiates circularly polarized waves. The monitoring system according to claim 1.

3. The aforementioned tracking device is It has a vibration sensor, and a mode switching unit that transitions from free space mode to sleep mode when the vibration sensor does not detect vibration for a certain period of time, and transitions from sleep mode to free space mode when the vibration sensor detects vibration, The relay communication unit transmits its own identification information at regular intervals in the free space mode, and further transmits identification information at intervals longer than the transmission interval in the free space mode in the sleep mode, and further performs the relay communication at least in the sleep mode. The monitoring system according to claim 1.

4. The sleep mode comprises at least a first sleep mode and a second sleep mode. The mode switching unit transitions from the first sleep mode to the second sleep mode when it does not receive identification information from another tracking device for a certain period of time. The relay communication unit transmits identification information at intervals longer than the transmission interval of identification information in the first sleep mode during the second sleep mode. The monitoring system according to claim 3.

5. The mode switching unit transitions from sleep mode to submersion mode when it does not receive identification information from other tracking devices for a certain period of time, and transitions from submersion mode to free space mode when the vibration sensor detects vibration. The relay communication unit transmits identification information at longer intervals than the transmission of identification information in the sleep mode in the submersion mode, and furthermore, does not perform the relay communication in the submersion mode. The monitoring system according to claim 3.

6. The sleep mode comprises at least a first sleep mode and a second sleep mode. The mode switching unit transitions from sleep mode to submersion mode when it does not receive identification information from other tracking devices for a certain period of time, and transitions from submersion mode to free space mode when the vibration sensor detects vibration. The relay communication unit transmits identification information at intervals longer than the transmission interval of identification information in the first sleep mode during the second sleep mode, and further transmits identification information at intervals longer than the transmission interval of identification information in the sleep mode during the submersion mode, and further does not perform the relay communication during the submersion mode. The monitoring system according to claim 3.

7. The relay communication unit transmits both its own identification information and the identification information received from other tracking devices, along with relay count information that allows it to determine which relay communication it is. The generation unit generates a network configuration including the installation order of the tracking device based on the identification information and the relay count information. The monitoring system according to claim 1.

8. The antenna section has a configuration in which signals with a relative phase difference of 90 degrees are input to two feed points, or a configuration in which two corners opposite each other in the diagonal direction of a roughly rectangular patch are cut off. The monitoring system according to claim 1.

9. A monitoring method performed by a monitoring system for cables inserted into buried pipes, The monitoring system comprises a plurality of tracking devices installed at predetermined intervals along the cable and constituting a bus-type or star-type network, and a monitoring device located at the root of the network. The aforementioned tracking device A radiation process in which omnidirectional radio waves are emitted at a resonant frequency where λ / 2 is less than or equal to the diameter of the circular buried pipe or the length of the longer side of the rectangular cross-section of the square buried pipe, The system includes a relay communication step that receives identification information from other tracking devices and transmits the received identification information and the identification information of the own device to perform relay communication from downstream to upstream. The aforementioned monitoring device The system includes a generation step of generating a network configuration based on the identification information obtained by the relay communication, Monitoring method.

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