Monitoring system, monitoring method and monitoring program

Abstract

To provide a monitoring system, a monitoring method and a monitoring program capable of accurately determining whether a distance between two positions where a unit is installed is abnormal or not.SOLUTION: A monitoring system comprises: setting means for setting a threshold value based on a moving average value of a first changing amount of a distance between a first unit installed at a first position and a second unit installed at a second position spaced apart from the first position in a plurality of first timings, and a moving average value of a first temperature at the plurality of first timings; determination means for determining whether the distance between the first position and the second position is abnormal by comparing a value based on a second changing amount of a distance between the first unit and the second unit at a second timing with the threshold value; and an output unit for outputting information regarding a determination result by the determination means.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Conventionally, a monitoring system has been developed for monitoring the displacement of a structure such as a bridge for the purpose of maintaining and managing the structure. The monitoring system notifies, for example, the amount of change in the distance between units installed at two positions spaced apart from each other on the structure.

[0003] For example, Patent Document 1 discloses a gap width data collection system including a plurality of cases, a scale section disposed in a space formed by the housing section of each case and movable in a predetermined direction, and a sensor section. Each case is installed on a structure across a gap in the structure, and the sensor section measures the length between a first point and a second point on the scale section that span the gap. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-120521 A Summary of the Invention [Problem to be solved by the invention]

[0005] In order to efficiently carry out long-term maintenance, the monitoring system is required to distinguish large displacements that do not occur on a daily basis from routine displacements, and to notify the occurrence of non-routine displacements as an abnormality.

[0006] However, the distance changes due to not only unusual changes in the structure but also everyday temperature, so the monitoring system is required to accurately determine whether the distance between the two positions where the units are installed is abnormal, regardless of temperature changes.

[0007] An object of the present invention is to provide a monitoring system that can accurately determine whether or not the distance between two positions where units are installed is abnormal. [Means for solving the problem]

[0008] The monitoring system of the present invention has a setting means for setting a threshold value based on a moving average value of a first amount of change in distance between a first unit installed at a first position and a second unit installed at a second position separated from the first position at multiple first points in time and a moving average value of a first temperature at multiple first points in time, a determination means for determining whether or not the distance between the first position and the second position is abnormal by comparing a value based on the second amount of change in the distance between the first unit and the second unit at the second point in time with the threshold value, and an output unit for outputting information regarding the determination result by the determination means.

[0009] In addition, in the monitoring system according to the present invention, it is preferable that the monitoring system further includes a calculation means for calculating a relational equation showing the relationship between the moving average value of the first change amount and the moving average value of the first temperature by performing linear regression analysis or multiple regression analysis on the moving average value of the first change amount at a plurality of first time points and the moving average value of the first temperature at a plurality of first time points, and the setting means further sets the threshold value based on the relational equation.

[0010] Furthermore, in the monitoring system according to the present invention, it is preferable that the setting means calculates an annual minimum or maximum amount of change in the first amount of change based on an annual maximum or minimum temperature of the first temperature, and sets the threshold value based on an annual minimum or maximum amount of change in the first amount of change.

[0011] In addition, in the monitoring system of the present invention, it is preferable that the multiple first time points span multiple days, and the setting means calculates a daily change range, which is the maximum value of the daily change range of the first change amount, and sets the threshold value based on the daily change range.

[0012] In addition, in the monitoring system of the present invention, it is preferable that the setting means sets a threshold value based on the relational equation and an average value of the second temperature at the multiple second time points, and the determination means determines whether or not the distance between the first position and the second position is abnormal by comparing the second change amount or the average value of the second change amount with the threshold value.

[0013] The monitoring method of the present invention sets a threshold value based on a moving average value of a first amount of change in distance between a first unit installed at a first position and a second unit installed at a second position separated from the first position at multiple first points in time, and a moving average value of a first temperature at multiple first points in time, and determines whether the distance between the first position and the second position is abnormal by comparing a value based on the second amount of change in the distance between the first unit and the second unit at the second point in time with the threshold value, and outputs information related to the determination result.

[0014] The program of the present invention is a program for controlling a measuring device, and causes the measuring device to set a threshold value based on a moving average value of a first amount of change in the distance between a first unit installed at a first position and a second unit installed at a second position separated from the first position at multiple first points in time, and a moving average value of a first temperature at multiple first points in time, determine whether or not the distance between the first position and the second position is abnormal by comparing a value based on the second amount of change in the distance between the first unit and the second unit at the second point in time with the threshold value, and output information related to the determination result. Effect of the Invention

[0015] The monitoring system, monitoring method, and monitoring program according to the present invention are capable of accurately determining whether or not the distance between two positions where units are installed is abnormal. [Brief description of the drawings]

[0016] [Figure 1] 1 is a configuration diagram of an example of a monitoring system 1. FIG. [Diagram 2]FIG. 1 is a schematic diagram for explaining the configuration of a measurement device 100. [Diagram 3] FIG. 1 is a schematic diagram for explaining the configuration of a measurement device 100. [Figure 4] FIG. 1 is a block diagram showing a schematic configuration of a measurement device 100. [Diagram 5] 2 is a block diagram showing a schematic configuration of an information processing device 200. FIG. [Figure 6] 13 is a flowchart showing an example of the flow of a management process. [Figure 7] Graph (A) is a graph showing the first change amount and the change in temperature, and graph (B) is a graph showing the change in the moving average value of the first change amount and the moving average value of the first temperature. [Figure 8] 6A and 6B are correlation diagrams between the moving average value of the first change amount and the moving average value of the first temperature. [Figure 9] 4A is a graph showing a first change amount and a change in a moving average value of the first change amount, and FIG. 4B is a correlation diagram between the moving average value of the first change amount and the moving average value of the first temperature. [Figure 10] 11 is a flowchart showing an example of the flow of a measurement process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, various embodiments of the present invention will be described with reference to the drawings. It should be noted that the technical scope of the present invention is not limited to these embodiments, but covers the inventions described in the claims and their equivalents.

[0018] In the following, the occurrence of a displacement (non-steady displacement) that is significantly different from the everyday displacement (steady displacement), in other words, the measurement of a movement amount (non-steady value of movement amount) that is significantly different from the movement amount measured on a daily basis (steady value of movement amount), is referred to as an abnormality or displacement abnormality in a structure (e.g., a bridge).

[0019] FIG. 1 is a configuration diagram of an example of a monitoring system 1 according to the present invention.

[0020] The monitoring system 1 includes one or more measuring devices 100, an information processing device 200, one or more structure manager terminals 300, and one or more device manager terminals 400. The measuring devices 100, the information processing device 200, the structure manager terminals 300, and the device manager terminals 400 are communicatively connected to each other via a first network N1 and a second network N2. The first network N1 is, for example, a mobile phone network. The measuring devices 100 are communicatively connected to the first network N1 via a base station. The first network N1 may be a wireless LAN (Local Area Network) or the like. In that case, the measuring devices 100 may be communicatively connected to the first network N1 via an access point. The second network N2 is an intranet or the Internet or the like. The first network N1 and the second network N2 are communicatively connected to each other via a gateway device or the like. The information processing device 200, the structure manager terminals 300, and the device manager terminals 400 are communicatively connected to the second network N2.

[0021] The monitoring system 1 monitors the occurrence of abnormalities in structures such as bridges, tunnels, or buildings. Each structure manager terminal 300 is a device used by a user (customer) of the monitoring system 1, i.e., a manager of a structure (monitoring target) (hereinafter, may be referred to as a structure manager). Each structure manager terminal 300 is a personal computer, a notebook personal computer, a tablet computer, a smartphone, etc. Each device manager terminal 400 is a device used by a manager (hereinafter, may be referred to as a device manager) of a measuring device 100 (monitoring system 1). Each device manager terminal 400 is a personal computer, a notebook personal computer, a tablet computer, a smartphone, etc.

[0022] 2 and 3 are schematic diagrams for explaining the configuration of the measuring device 100. Fig. 2 is a perspective view of the measuring device 100 during use, and Fig. 3 is a perspective view of the measuring device 100 with the frame of the first unit 110 removed.

[0023] Each of the multiple measuring devices 100 has the same configuration and function. As shown in FIG. 2 and FIG. 3, the measuring device 100 measures the change in distance between the reference object T2 and the object T1 to be measured, which is disposed across a gap with respect to the reference object T2, thereby measuring the displacement of the object T1 with respect to the reference object T2, i.e., the change in the relative position. The gap is a gap, a space between two objects provided as a gap other than a gap, or a gap caused by a crack. The object T1 is, for example, a bridge girder, a tunnel, or a building. When the object T1 is a bridge girder, the reference object T2 is, for example, a bridge abutment on which the end of the bridge girder is disposed. When the object T1 is a tunnel, the reference object T2 is, for example, a joint portion connecting the segments of the tunnel. When the object T1 is a building, the reference object T2 is, for example, one of an expansion joint portion connecting the buildings. In addition, the reference object T2 and the target object T1 may be the same structure, such as the various parts of a bridge girder with a gap between them, or the wall surfaces of a tunnel with a gap between them.

[0024] The measuring device 100 includes a first unit 110, a second unit 120, and a connection unit 130. The first unit 110 is placed at an appropriate position P1 near the gap in the target object T1. The second unit 120 is placed at a position P2 in the reference object T2 across the gap from the position P1 in the target object T1, that is, at a position P2 in the reference object T2 spaced apart from the position P1 in the target object T1. The position P1 is an example of a first position, and the position P2 is an example of a second position. The connection unit 130 is placed between the first unit 110 and the second unit 120.

[0025] Note that the first unit 110 may be installed at position P2 in the reference object T2 and the second unit 120 at position P1 in the object T1, instead of the first unit 110 being installed at position P1 in the object T1 and the second unit 120 being installed at position P2 in the reference object T2. In that case, the position P2 in the reference object T2 is an example of the first position, and the position P1 in the object T1 is an example of the second position. In the case where a bridge is the object of monitoring, one of the first position where the first unit 110 is installed and the second position where the second unit 120 is installed is set to one of the bridge girder and the abutment of the bridge. Meanwhile, the other of the first position where the first unit 110 is installed and the second position where the second unit 120 is installed is set to the other of the bridge girder and the abutment of the bridge.

[0026] The first unit 110 is composed of a housing (case) surrounded by a frame having a substantially rectangular parallelepiped shape, and contents such as a first sensor 112. A bottom surface 110a of the first unit 110 is an installation surface that is installed on a surface such as the top surface, bottom surface, or side surface of the target T1. An opening 110c is formed in a side surface 110b of the first unit 110 on the second unit 120 side. An opening 110e is formed in an upper surface 110d of the first unit 110. In the first unit 110, a fixing member 111, a first sensor 112, a second sensor 113, a temperature sensor 114, a battery 115, a board 116, a first communication device 117, an antenna 118, a control unit 119, and the like are arranged.

[0027] The second unit 120 is a housing (case) surrounded by a frame having a substantially rectangular parallelepiped shape. A bottom surface 120a of the second unit 120 is a mounting surface that is mounted on a surface such as the top surface, bottom surface, or side surface of the reference object T2. A holding portion 121 is provided on a side surface 120b of the second unit 120 on the first unit 110 side.

[0028] The connection part 130 is disposed between the first unit 110 and the second unit 120. One end of the connection part 130 is attached to the holding part 121 of the second unit 120. The other end of the connection part 130 is disposed inside the first unit 110 via an opening 110c formed in a side surface 110b of the first unit 110. The connection part 130 has a rod part 131 and the like.

[0029] In FIG. 2, arrow A1 indicates the extension direction of rod portion 131, arrow A2 indicates the height direction, and arrow A3 indicates the lateral direction A3 perpendicular to extension direction A1 of rod portion 131 and height direction A2.

[0030] The initial position of the rod portion 131 is set to a position where the tip of the rod portion 131 (the position detected by the first sensor 112) is located at the center of the detectable range of the first sensor 112. This allows the measuring device 100 to maximize the measurable upper limit of the moving distance of the object T1 in both cases where the object T1 moves in a direction away from the reference object T2 and where the object T1 moves in a direction approaching the reference object T2.

[0031] The first sensor 112 is an example of a sensor. The first sensor 112 is disposed inside the first unit 110 at a position facing the tip of the rod portion 131 of the connection portion 130 (the end opposite to the second unit 120). The end of the rod portion 131 opposite to the second unit 120 is an example of the other end of the connection portion. The first sensor 112 is a linear position sensor, for example, a variable resistor. The first sensor 112 includes a resistor extending along the extension direction A1 of the rod portion 131 and a contact (slider) that moves on the resistor according to the movement of the tip of the rod portion 131. A constant voltage is applied to the terminals provided on both ends of the resistor, and the voltage output from the contact varies depending on the position of the contact on the resistor. Therefore, the first sensor 112 can detect the position of the tip of the rod portion 131 based on the voltage output from the contact and measure the movement amount of the connection portion 130. The first sensor 112 outputs to the control unit 119 a displacement signal indicating the displacement of the rod portion 131 corresponding to the difference between the voltage output from the contact when the rod portion 131 is disposed at the initial position and the voltage currently output from the contact, i.e., the amount of movement of the connection portion 130. The amount of movement includes positive and negative values. For example, it is determined that the amount of movement in the direction in which the first unit 110 moves away from the second unit 120 indicates a positive value, and the amount of movement in the direction in which the first unit 110 moves toward the second unit 120 indicates a negative value.

[0032] One end of the connection part 130 is attached to the holding part 121 of the second unit 120, so that the connection part 130 is fixed to the second unit 120 (does not slide in the extension direction A1). When the position P1 in the object T1 in which the first unit 110 is installed moves in the extension direction A1 relative to the position P2 in the reference object T2 in which the second unit 120 is installed, the first sensor 112 moves relative to the rod part 131, and as a result, the rod part 131 moves relatively in the extension direction A1 as seen from the first sensor 112. That is, the first sensor 112 measures the displacement of the other end side of the connection part 130 as the movement amount of the connection part 130, that is, the change in the distance between the position P2 in the reference object T2 in which the second unit 120 is installed and the position P1 in the object T1 in which the first unit 110 is installed.

[0033] The first sensor 112 may be a plurality of light emitters and light receivers arranged in line along the extending direction A1 of the rod portion 131. The light emitters and light receivers are arranged facing each other across the moving range of the tip of the rod portion 131. The first sensor 112 detects whether the rod portion 131 exists between each light emitter and each light receiver based on whether each light receiver receives light emitted from each light emitter arranged facing each other or does not receive light because it is blocked by the rod portion 131. The first sensor 112 outputs a displacement signal to the control unit 119 indicating the displacement of the rod portion 131 corresponding to the difference between the number of light receivers that receive light emitted from the light emitter when the rod portion 131 is arranged at the initial position and the number of light receivers that currently receive light emitted from the light emitter. Furthermore, the first sensor 112 may have a light emitter that irradiates light toward the tip of the rod portion 131, and a light receiver that receives the light that is irradiated by the light emitter and reflected by the tip of the rod portion 131. In this case, the first sensor 112 detects the displacement of the rod portion 131 based on the time from when the light emitter irradiates light to when the light receiver receives the light. Furthermore, the first sensor 112 may be any other sensor capable of detecting the displacement of the rod portion 131, such as an imaging sensor.

[0034] Second sensor 113 is a sensor for detecting the inclination of first unit 110.

[0035] The temperature sensor 114 is disposed inside the first unit 110. The temperature sensor 114 detects the temperature (air temperature) of the environment in which the measuring device 100 is installed, particularly inside the first unit 110, and outputs a temperature signal indicating the detected temperature to the control unit 119.

[0036] The battery 115 is a primary battery or a secondary battery. The battery 115 is connected to the first sensor 112, the second sensor 113, the temperature sensor 114, the first communication device 117, the antenna 118, and the control unit 119, and supplies power to the first sensor 112, the second sensor 113, the temperature sensor 114, the first communication device 117, the antenna 118, and the control unit 119. In addition, the first unit 110 is provided with a voltmeter (not shown) capable of measuring the battery voltage of the battery 115, and the control unit 119 can detect the battery voltage of the battery 115 by the voltmeter.

[0037] The first communication device 117 is an example of a first communication section and an output section, and is provided so as to be able to communicate with the information processing device 200. The first communication device 117 includes a wireless communication interface circuit and connects the measuring device 100 to a wireless communication network. The first communication device 117 performs wireless communication with a base station (not shown) via an antenna 118 using a Long Term Evolution (LTE) system, particularly a Low Power Wide Area (LPWA) system. Note that the communication system with the base station is not limited to the LTE system, and may be other communication systems such as a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (W-CDMA) system, or a Fifth Generation (5G) system, or may be a communication system to be used in the future. The first communication device 117 transmits data supplied from the control unit 119 to the information processing device 200 via the base station. The first communication device 117 supplies data received from the information processing device 200 via the base station to the control unit 119. Moreover, the first communication device 117 supplies the received radio wave intensity to the control unit 119 according to an instruction from the control unit 119. Note that the first communication device 117 may perform wireless communication with a Wifi (Wireless Fidelity) access point (not shown) via the antenna 118 in accordance with the wireless communication method of the IEEE802.11 standard.

[0038] The antenna 118 is an antenna sensitive to bands such as 2 GHz, 1.7 GHz, 900 MHz, 800 MHz, etc. The antenna 118 may be an antenna sensitive to bands such as 2.4 GHz, 5 GHz, etc.

[0039] The control unit 119 is a unit that controls the processing performed by the measuring device 100. The control unit 119 is, for example, an MCU (Micro Controller Unit). The control unit 119 will be described in detail later.

[0040] FIG. 4 is a block diagram showing a schematic configuration of the measurement device 100. As shown in FIG.

[0041] 4, the first sensor 112, the second sensor 113, the temperature sensor 114, the first communication device 117, and the control unit 119 are connected to each other. The control unit 119 includes a first storage device 140, a first processing circuit 150, and the like.

[0042] The first storage device 140 includes a semiconductor memory such as a random access memory (RAM) or a read only memory (ROM). The first storage device 140 stores computer programs, data, and the like used in processing by the first processing circuit 150. The computer programs are installed in the first storage device 140 from the information processing device 200 via the first communication device 117, or from an installation device via a serial communication circuit (not shown). The computer programs may be installed in the first storage device 140 from a computer-readable portable recording medium using a known setup program or the like. The portable recording medium is, for example, a compact disc read only memory (CD-ROM) or a digital versatile disc read only memory (DVD-ROM). The first storage device 140 also stores measurement information, determination parameters, and the like as data. Details of the measurement information, determination parameters, and the like will be described later.

[0043] The first processing circuit 150 is, for example, a CPU (Central Processing Unit). The first processing circuit 150 may be an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or the like. The first processing circuit 150 is connected to the first sensor 112, the second sensor 113, the temperature sensor 114, the first communication device 117, the first storage device 140, and the like, and controls each of these components. The first processing circuit 150 reads a program stored in the first storage device 140 and operates according to the read program, thereby functioning as a first acquisition means 151, a determination means 152, and a transmission means 153.

[0044] FIG. 5 is a block diagram showing a schematic configuration of the information processing device 200. As shown in FIG.

[0045] The information processing device 200 is, for example, a server. The information processing device 200 may be configured by a plurality of computers. As shown in Fig. 5, the information processing device 200 includes an operation device 201, a display device 202, a second communication device 203, a second storage device 210, and a second processing circuit 220. The operation device 201, the display device 202, the second communication device 203, the second storage device 210, and the second processing circuit 220 are connected to each other.

[0046] The operation device 201 has input devices such as a keyboard and a mouse, and an interface circuit that acquires signals from the input devices.

[0047] The display device 202 has a display configured with liquid crystal, organic EL, or the like, and an interface circuit that outputs image data to the display, and displays image data on the display according to instructions from the second processing circuit 220.

[0048] The second communication device 203 is an example of a second communication unit, and is provided to be able to communicate with a plurality of measuring devices 100. The second communication device 203 includes a wired or wireless communication interface circuit, and connects the information processing device 200 to a communication network. The second communication device 203 performs wired communication according to a communication protocol such as TCP / IP (Transmission Control Protocol / Internet Protocol). The second communication device 203 may perform wireless communication in the same manner as the first communication device 117. The second communication device 203 transmits data provided from the second processing circuit 220 to the measuring device 100, the structure manager terminal 300, or the device manager terminal 400. The first communication device 117 provides data received from the measuring device 100, the structure manager terminal 300, or the device manager terminal 400 to the second processing circuit 220.

[0049] The second storage device 210 includes, for example, a semiconductor memory such as a RAM or a ROM, a fixed disk device such as a hard disk, or a portable storage device such as an optical disk. The second storage device 210 stores computer programs, data, and the like used in processing by the second processing circuit 220. The computer programs are installed in the second storage device 210 from a server (not shown) via the second communication device 203. The computer programs may be installed in the second storage device 210 from a computer-readable portable recording medium using a known setup program or the like. The portable recording medium is, for example, a CD-ROM, a DVD-ROM, or the like. The second storage device 210 also stores, as data, measurement information, judgment parameters, and the like for each of the multiple measuring devices 100.

[0050] The second processing circuit 220 is, for example, a CPU. The second processing circuit 220 may be an LSI, an ASIC, a DSP, an FPGA, or the like. The second processing circuit 220 is connected to the operation device 201, the display device 202, the second communication device 203, the second storage device 210, and the like, and controls each of these units. The second processing circuit 220 reads a program stored in the second storage device 210 and operates according to the read program, thereby functioning as a control means 221, a second acquisition means 222, a calculation means 223, a setting means 224, and a notification means 225.

[0051] FIG. 6 is a flowchart showing an example of the flow of the management process executed by the information processing device 200.

[0052] An example of the operation of the management process of the information processing device 200 will be described below with reference to the flowchart shown in Fig. 6. Note that the flow of the operation described below is executed mainly by the second processing circuit 220 in cooperation with each element of the information processing device 200 based on a program stored in advance in the second storage device 210.

[0053] At any timing during execution of the management process, the control means 221 receives installation information from the device administrator terminal 400 used by the device administrator, and stores it in the second storage device 210. The installation information includes the device ID of the installed measuring device 100 and the date and time of transmission of the determination parameters, etc. The initial value of the date and time of transmission of the determination parameters is set to a date and time indicating no transmission (for example, blank).

[0054] First, the control means 221 judges whether or not measurement information has been received from any of the measuring devices 100 via the second communication device 203 (step S101). The measurement information includes the device ID of the measuring device 100, each measurement date and time when the measurement was performed, the temperature and movement amount of the measuring device 100 (first unit 110) at each measurement date and time, etc. If no new measurement information has been received, the control means 221 proceeds to step S103. On the other hand, if measurement information has been received, the control means 221 associates each piece of information included in the measurement information and stores it in the second storage device 210 (step S102).

[0055] Next, the control means 221 judges whether or not there is a measuring device 100 (hereinafter, sometimes referred to as a setting-required device) that has received measurement information for a sample period but has not yet transmitted a judgment parameter among the measuring devices 100 whose device IDs are stored in the second storage device 210 (step S103). The sample period is set in advance to a period (e.g., one month) during which sufficient data (a first change amount and a first temperature, which will be described later) can be acquired for each measuring device 100 to calculate a judgment parameter. The control means 221 specifies, as a setting-required device, a measuring device 100 that has received measurement information for the sample period and whose judgment parameter transmission date and time stored in the second storage device 210 is set to a date and time indicating no transmission. If there is no setting-required device, the control means 221 moves the process to step S110.

[0056] On the other hand, if a setting-required device exists, the second acquisition means 222 acquires the movement amount of the connection unit 130 of the setting-required device at multiple time points up to the present (the amount of change in the distance between the first unit 110 and the second unit 120) and the temperature (or the ambient temperature) of the setting-required device at each of those time points (step S104). The multiple time points span multiple days. Hereinafter, the multiple time points in the sample period may be referred to as first time points, the above movement amount (amount of change) at the first time point may be referred to as the first amount of change, and the above temperature at the first time point may be referred to as the first temperature. For example, the second acquisition means 222 acquires the movement amount of the connection unit 130 and the temperature of the setting-required device at each measurement date and time up to the present stored in the second storage device 210 in association with the device ID of the setting-required device as the first amount of change and the first temperature. In this manner, the second acquisition means 222 acquires a first amount of change in the distance between the first unit 110 installed at position P1 and the second unit 120 installed at position P2 at multiple first points in time, and a first temperature at each first point in time.

[0057] Next, the calculation means 223 calculates the moving average value of the first change amount at a plurality of first time points and the moving average value of the first temperature at a plurality of first time points (step S105). The calculation means 223 calculates the moving average value of the first change amount at a predetermined consecutive period among the plurality of first time points and the moving average value of the first temperature. The predetermined period is set to, for example, ¼ or more and ⅔ or less of the sample period. For example, when the sample period is one month, the predetermined period is set to 7 days or more and 20 days or less. If the predetermined period is too short, the first change amount and the first temperature are not sufficiently smoothed, and the influence of data fluctuations at each measurement timing becomes large. On the other hand, if the predetermined period is too long, the moving average value of the first change amount and the moving average value of the first temperature for a sufficient number of samples cannot be obtained, and the relationship between the first change amount and the first temperature may not be properly calculated. By appropriately setting the predetermined period, the calculation means 223 can appropriately smooth the first change amount and the first temperature and properly calculate the relationship between the first change amount and the first temperature.

[0058] FIG. 7(A) is a graph showing the first change amount and the change in the first temperature in a specific period. The horizontal axis of FIG. 7(A) indicates each measurement date and time, the vertical axis on the left side indicates the first change amount at each measurement date and time, and the vertical axis on the right side indicates the first temperature at each measurement date and time. Graph G1 of FIG. 7(A) is a graph showing the change in the first change amount at each measurement date and time, and graph G2 is a graph showing the change in the first temperature at each measurement date and time. As shown in FIG. 7(A), the first temperature and the first change amount have a correlation in which the higher the first temperature is, the smaller the first change amount, and the lower the first temperature is, the larger the first change amount. Note that the first temperature and the first change amount may also have a correlation in which the higher the first temperature is, the larger the first change amount, and the lower the first temperature is, the smaller the first change amount.

[0059] FIG. 7(B) is a graph showing the change in the moving average value G3 of the first change amount G1 and the moving average value G4 of the first temperature G2 during the specific period shown in FIG. 7(A). The horizontal axis of FIG. 7(B) shows each measurement date and time, the vertical axis on the left side shows the moving average value of the first change amount at each measurement date and time, and the vertical axis on the right side shows the moving average value of the first temperature at each measurement date and time. As shown in FIG. 7(A) and (B), the first temperature and the first change amount are appropriately smoothed by calculating the moving average value. As a result, the influence of the diurnal variation having a high frequency component compared to the seasonal variation is removed from the first change amount and the first temperature, and the correlation between the first temperature and the first change amount becomes clearer.

[0060] Next, the calculation means 223 calculates a relational expression indicating the relationship between the moving average value of the first change amount at a plurality of first time points and the moving average value of the first temperature at each first time point (step S106).

[0061] FIG. 8(A) is a correlation diagram between the moving average value of the first change amount and the moving average value of the first temperature in a specific period. The horizontal axis of FIG. 8(A) indicates the moving average value of the first temperature, and the vertical axis indicates the moving average value of the first change amount. Each point E1 in FIG. 8(A) indicates a point corresponding to a combination of each moving average value of the first change amount and the moving average value of the first temperature in a specific period. As shown in FIG. 8(A), the moving average value of the first change amount has a substantially linear relationship with the moving average value of the first temperature, with a negative slope. As described above, the correlation between the moving average value of the first temperature and the moving average value of the first change amount is clearer than the correlation between the first change amount and the first temperature, and has a higher linearity than the correlation between the first change amount and the first temperature.

[0062] For example, the calculation means 223 calculates a relational equation (a one-dimensional linear equation) indicating the relationship between the moving average value of the first change amount and the moving average value of the first temperature by performing a linear regression analysis on the moving average value of the first temperature at each first time point and the moving average value of the first change amount at each first time point. That is, the calculation means 223 calculates a correlation function represented by the following equation (1) as the relational equation for the moving average value r(k) of the first change amount and the moving average value k of the first temperature. r(k)=a k+b (1) Here, a and b are constants.

[0063] For example, the calculation means 223 calculates a regression line showing the relationship between the first change amount and the first temperature using the least squares method, the maximum likelihood estimation method, the Bayesian estimation method, or the like. In the example shown in Fig. 8(A), a regression line E2 passing through the center of the distribution range of the correlation of each point E1 corresponding to the combination of each first change amount and each first temperature is calculated as the relational expression. In this way, the calculation means 223 can accurately calculate the relationship between the moving average value of the first change amount and the moving average value of the first temperature by performing a linear regression analysis on the moving average value of the first temperature at each first time point and the moving average value of the first change amount at each first time point.

[0064] The calculation means 223 may calculate a relational equation (one-dimensional and third-order or higher relational equation) indicating the relationship between the moving average value of the first change amount and the moving average value of the first temperature by performing multiple regression analysis on the moving average value of the first temperature at each first time point and the moving average value of the first change amount at each first time point. In this case, the calculation means 223 calculates the relational equation indicating the relationship between the first change amount and the first temperature using the least squares method, maximum likelihood estimation method, Bayesian estimation method, or the like. The calculation means 223 can accurately calculate the relationship between the moving average value of the first change amount and the moving average value of the first temperature even when performing multiple regression analysis on the moving average value of the first temperature at each first time point and the moving average value of the first change amount at each first time point.

[0065] Next, the setting means 224 calculates the annual minimum change in the first change amount based on the annual maximum temperature of the first temperature, and calculates the annual maximum change in the first change amount based on the annual maximum temperature of the first temperature (step S107). The setting means 224 acquires the annual maximum temperature and the annual minimum temperature. For example, the setting means 224 sets predetermined temperatures (e.g., 50°C and -5°C) as the annual maximum temperature and the annual minimum temperature. By using the predetermined temperatures as the annual maximum temperature and the annual minimum temperature, the setting means 224 can calculate the annual minimum change and annual maximum change in the first change amount in a short time and with a low load.

[0066] The setting means 224 may set predetermined temperatures for each region where the measuring device 100 is installed as the annual maximum temperature and the annual minimum temperature. The setting means 224 may also acquire the annual maximum temperature and the annual minimum temperature of the region where the setting-required device is installed from the regional meteorological observation system (AMeDAS) of the Japan Meteorological Agency or the like. The information processing device 200 stores in advance in the second storage device 210 a table or a relational expression showing the relationship between the temperature measured by the measuring device 100 and the air temperature. The setting means 224 calculates the annual maximum temperature and the annual minimum temperature of the setting-required device from the annual maximum temperature and the annual minimum temperature using the previously stored table or relational expression. The setting means 224 may also acquire, as the annual maximum temperature and the annual minimum temperature, the maximum value and the minimum value of the temperature detected in the last year by the temperature sensor 114 of the measuring device 100 installed within a predetermined distance from the setting-required device among the measuring devices 100 of the setting-required device or the monitoring system 1. This enables the setting means 224 to more accurately calculate the annual minimum and maximum amounts of change in the first amount of change that correspond to the characteristics of the installation location of the measuring device 100.

[0067] The setting means 224 calculates the smaller of the moving average values ​​r(k) of the first change obtained by substituting the annual maximum temperature and the annual minimum temperature for the moving average value k of the first temperature in the relational expression calculated by the calculation means 223 in step S106 as the annual minimum change in the first change, and calculates the larger of the moving average values ​​r(k) as the annual maximum change in the first change. By using the annual maximum temperature and the annual minimum temperature, the setting means 224 can easily calculate the annual minimum change and annual maximum change in the first change according to the installation location.

[0068] Figure 8(B) shows how the annual minimum and maximum changes are calculated using the correlation shown in Figure 8(A). In this example, the change corresponding to the annual minimum temperature is the largest, and the change corresponding to the annual maximum temperature is the smallest.

[0069] Next, the setting means 224 calculates the intraday variation range (step S108). The intraday variation range is the maximum value among the daily variation ranges of the first change amount.

[0070] Fig. 9(A) is a graph showing the changes in the first change amount G1 and the moving average value G3 of the first change amount during a specific period shown in Fig. 7(A) and (B). The horizontal axis of Fig. 9(A) shows each measurement date and time, and the vertical axis shows the first change amount at each measurement date and time.

[0071] The setting means 224 specifies a maximum value M1 and a minimum value M2 of each first change amount for each day, and calculates a difference W between the specified maximum value M1 and minimum value M2. The setting means 224 calculates the maximum value of the difference W calculated for each day as the intraday change range.

[0072] Next, the setting means 224 sets a threshold value to be compared with a value based on the amount of change in the distance between the first unit 110 and the second unit 120 during operation (step S109). The setting means 224 stores the set threshold value in the second storage device 210 in association with the device ID of the device requiring setting as a determination parameter for determining whether or not the distance between the first position and the second position is abnormal.

[0073] FIG. 9(B) is a correlation diagram between the moving average value of the first change amount and the moving average value of the first temperature in a specific period shown in FIG. 8(B).

[0074] The setting means 224 sets an upper limit value and a lower limit value as threshold values. The setting means 224 sets a value obtained by subtracting a predetermined value from the annual minimum change amount of the first change amount calculated based on the relational expression E2 indicating the relationship between the moving average value of the first change amount and the moving average value of the first temperature, and the annual maximum temperature of the first temperature, as the lower limit value. The setting means 224 also sets a value obtained by adding a predetermined value to the annual maximum change amount of the first change amount calculated based on the relational expression E2 indicating the relationship between the moving average value of the first change amount and the moving average value of the first temperature, and the annual minimum temperature of the first temperature, as the upper limit value. The predetermined value is set to a value obtained by further adding a margin to the intraday change range. The margin includes a temperature margin, a bridge design margin, and a measurement margin.

[0075] The temperature margin is a margin that is added in consideration of the possibility that the annual maximum temperature and the annual minimum temperature may vary from year to year. For example, the moving average value r(k) of the first change amount obtained by substituting a predetermined temperature (e.g., 5°C) into the moving average value k of the first temperature in the relational expression E2 is set as each of the temperature margin for the lower limit value and the temperature margin for the upper limit value. Note that different temperatures may be used for calculating the lower limit value and the temperature for calculating the upper limit value. Also, different temperatures may be used for each region where the measuring device 100 is installed. Also, the margin does not have to include the temperature margin.

[0076] Bridge design margins are margins provided to bridges according to the amount of margin for installation error during bridge construction. A value of 10 mm or less is set for the amount of margin based on the expansion joint design guidelines (April 2019) and bridge design documents, and half of the amount of margin is preset as the lower limit bridge design margin and the upper limit bridge design margin.

[0077] The measurement margin is a margin added in consideration of the measurement error between the amount of change in the distance between the first unit 110 and the second unit 120 measured in advance and the amount of change in the distance between the first unit 110 and the second unit 120 measured during operation, i.e., the measurement error between the first amount of change and a second amount of change described below. A predetermined size (e.g., 0.1 mm) is set as each of the measurement margin for the lower limit value and the measurement margin for the upper limit value.

[0078] In this way, the setting means 224 sets the threshold value based on the moving average value of the first change amount at a plurality of first time points and the moving average value of the first temperature at a plurality of first time points. The setting means 224 smoothes the change amount of distance and the temperature measured by each measuring device 100, thereby making it possible to remove the influence of daily temperature fluctuations, which have a high frequency component compared to seasonal temperature fluctuations, on the distance between the first unit 110 and the second unit 120.

[0079] Furthermore, the setting means 224 sets the threshold value based on a relational expression E2 that indicates the relationship between the moving average value of the first change amount and the moving average value of the first temperature. This allows the setting means 224 to easily set a highly reliable value as the threshold value to be compared with the amount of change in the distance between the first unit 110 and the second unit 120, which varies depending on the temperature.

[0080] Furthermore, the setting means 224 sets the threshold value based on the annual minimum and maximum changes in the first change amount. By taking into account the annual minimum and maximum changes in the first change amount, the setting means 224 can prevent the seasonal variation in the second change amount from being erroneously determined as a displacement anomaly with respect to the distance between the first unit 110 and the second unit 120.

[0081] Furthermore, the setting means 224 sets the threshold value based on the daily variation range. By taking the daily variation range into consideration, the setting means 224 can suppress erroneous determination of the daily variation of the second change amount as a displacement abnormality for the distance between the first unit 110 and the second unit 120.

[0082] Furthermore, the setting means 224 sets the threshold value taking into consideration the temperature margin, the bridge design margin, and the measurement margin. This makes it possible for the monitoring system 1 to suppress erroneous notification of the occurrence of a displacement abnormality when no displacement abnormality has occurred, thereby improving the reliability of the system from users.

[0083] Furthermore, the setting means 224 sets a threshold value for each device requiring setting, i.e., for each of the multiple measuring devices 100. This allows the information processing device 200 to set, for each measuring device 100, a determination parameter suitable for the installation environment of each measuring device 100.

[0084] Furthermore, the information processing device 200 sets the judgment parameters after installing each measuring device 100 and acquiring sufficient data (first change amount and first temperature) for calculating the judgment parameters. That is, the calculation means 223 calculates a relational expression indicating the relationship between the moving average value of the first change amount and the moving average value of the first temperature for each of the plurality of measuring devices 100 when the first acquisition means 151 acquires the first change amount and the first temperature at the plurality of first time points. The setting means 224 sets a threshold value for each of the plurality of measuring devices 100 when the first acquisition means 151 acquires the first change amount and the first temperature at the plurality of first time points and the calculation means 223 calculates the relational expression. This allows the information processing device 200 to set the judgment parameters for each measuring device 100 at an appropriate timing.

[0085] The setting means 224 may set only one of the upper limit value or the lower limit value as the threshold value. In that case, the setting means 224 calculates only one of the annual minimum change amount or the annual maximum change amount of the first change amount based on the annual maximum temperature or the annual minimum temperature of the first temperature. The setting means 224 sets only one of the upper limit value or the lower limit value based on the annual minimum change amount or the annual maximum change amount of the first change amount.

[0086] The setting means 224 may set the threshold value without using a relational expression indicating the relationship between the moving average value of the first change amount and the moving average value of the first temperature. For example, the setting means 224 sets the threshold value using a learning model that is pre-trained using a plurality of sets of the moving average value of the first change amount and the moving average value of the first temperature as learning data. The learning model is trained, for example, using a known machine learning technique such as a decision tree, so that when a temperature is input, a change amount corresponding to the temperature is output. The setting means 224 inputs various temperatures within a range from the annual minimum temperature to the annual maximum temperature into the pre-trained learning model, sets a value obtained by adding a predetermined value to the maximum value of the change amount output from the learning model as the upper limit value, and sets a value obtained by subtracting a predetermined value from the minimum value of the change amount output from the learning model as the lower limit value.

[0087] Next, the control means 221 judges whether or not a parameter request signal requesting a judgment parameter has been received from any of the measuring devices 100 via the second communication device 203 (step S110). The parameter request signal includes the device ID of the measuring device 100. If a new parameter request signal has not been received, the control means 221 proceeds to step S112. On the other hand, if a parameter request signal has been received, the control means 221 transmits the judgment parameter (threshold value) stored in the second storage device 210 in association with the device ID included in the parameter request signal to the measuring device 100 that transmitted the parameter request signal via the second communication device 203 (step S111). Then, the control means 221 sets the current date and time to the judgment parameter transmission date and time stored in the second storage device 210 in association with the device ID included in the parameter request signal.

[0088] Next, the notification means 225 judges whether or not displacement anomaly information indicating that a displacement anomaly has occurred is received from any of the measuring devices 100 via the second communication device 203 (step S112). The displacement anomaly information includes the device ID of the measuring device 100. If no new displacement anomaly information has been received, the notification means 225 returns the process to step S101.

[0089] On the other hand, when the displacement anomaly information is received, the notification means 225 transmits the displacement anomaly notification to the contact information of the structure manager stored in the second storage device 210 in association with the device ID included in the displacement anomaly information via the second communication device 203 (step S113), and returns the process to step S101. The displacement anomaly notification includes the device ID included in the displacement anomaly information, the identification information of the corresponding structure, and a guide message encouraging the user to check the corresponding structure. The displacement anomaly information is transmitted when a value based on the amount of movement of the connection part 130 measured by the first sensor 112 in the measuring device 100 exceeds a threshold value. That is, when a value based on the amount of movement of the connection part 130 measured by the first sensor 112 exceeds a threshold value, that is, when an abnormality occurs in the structure, the notification means 225 notifies the contact information of the structure manager of the occurrence of the abnormality. The structure manager can quickly check the state of the structure and take appropriate measures by viewing the displacement anomaly notification using the structure manager terminal 300.

[0090] The notification means 225 may send the displacement abnormality notification to the contact address of the structure manager as well as the contact address of the equipment manager. In this case, the structure manager may forward the displacement abnormality notification to the contact address of the equipment manager. The equipment manager can quickly check the status of the corresponding measuring device 100 by viewing the displacement abnormality notification using the equipment manager terminal 400 and replace it if necessary.

[0091] FIG. 10 is a flowchart showing an example of the flow of the measurement process executed by the measurement device 100.

[0092] An example of the operation of the measurement process of the measuring device 100 will be described below with reference to the flowchart shown in Fig. 10. Note that the flow of the operation described below is executed mainly by the first processing circuit 150 in cooperation with each element of the measuring device 100 based on a program stored in advance in the first storage device 140.

[0093] First, the first acquisition means 151 determines whether or not a first interval has elapsed (step S201). The first interval is set in advance as an interval (for example, a predetermined time less than one hour) at which the state of the measuring device 100 should be monitored. If the first interval has not yet elapsed, the first acquisition means 151 proceeds to step S209.

[0094] On the other hand, when the first interval has elapsed, the first acquisition means 151 acquires the current date and time. The first acquisition means 151 also acquires a temperature signal from the temperature sensor 114, and acquires the temperature indicated by the acquired temperature signal. The first acquisition means 151 also acquires a displacement signal from the first sensor 112, and acquires the amount of movement indicated by the acquired displacement signal (step S202). Hereinafter, each time point for each first interval after the sample period may be referred to as a second time point, the amount of movement at the second time point may be referred to as a second amount of change, and the temperature at the second time point may be referred to as a second temperature. The first acquisition means 151 acquires the amount of movement and the temperature in step S202 as the second amount of change and the second temperature at the second time point, respectively.

[0095] Next, the determination means 152 determines whether or not a determination parameter (threshold value) has been received from the information processing device 200 (step S203). The determination parameter is transmitted from the information processing device 200 in a process described below, and is stored in the first storage device 140. The determination means 152 determines whether or not the determination parameter has been received from the information processing device 200, depending on whether or not the determination parameter has been stored in the first storage device 140. If the determination parameter has not yet been received, the determination means 152 proceeds to step S208.

[0096] On the other hand, if the judgment parameters have already been received, the judgment means 152 judges whether the acquired second change amount (movement amount) exceeds the threshold value included in the judgment parameters (step S204). If the second change amount is greater than the upper limit value or less than the lower limit value, the judgment means 152 judges that the second change amount has exceeded the threshold value. On the other hand, if the second change amount is equal to or less than the upper limit value and equal to or greater than the lower limit value, the judgment means 152 judges that the second change amount has not exceeded the threshold value. The second change amount is an example of a value based on the second change amount.

[0097] Moreover, the determination means 152 may use the average value of the second change amount instead of the second change amount to determine whether or not the second change amount has exceeded the threshold value. The average value of the second change amount is the average value of the second change amount in a consecutive predetermined period among the plurality of second time points. The predetermined period is set to the same period as the predetermined period in which the moving average value of the first change amount is calculated. The predetermined period may be set to a period shorter than the predetermined period in which the moving average value of the first change amount is calculated. In this case, the threshold value is set so as not to include the intraday change range calculated in step S108 of FIG. 6. That is, the predetermined value set when calculating the threshold value in step S109 of FIG. 6 is set to the margin itself (so as not to include the intraday change range). The determination means 152 determines that the second change amount has exceeded the threshold value when the average value of the second change amount is greater than the upper limit value or less than the lower limit value. On the other hand, the determination means 152 determines that the second change amount has not exceeded the threshold value when the average value of the second change amount is equal to or less than the upper limit value and equal to or greater than the lower limit value. The determination means 152 may determine that the second change amount has exceeded the threshold value when the average value of the second change amount is greater than the upper limit value, and may determine that the second change amount has not exceeded the threshold value when the average value of the second change amount is equal to or less than the upper limit value. The determination means 152 may determine that the second change amount has exceeded the threshold value when the average value of the second change amount is less than the lower limit value, and may determine that the second change amount has not exceeded the threshold value when the average value of the second change amount is equal to or greater than the lower limit value. In this case, the determination means 152 determines whether a predetermined period has elapsed, and does not determine whether a displacement abnormality has occurred until the predetermined period has elapsed. In this case, the average value of the second change amount is an example of a value based on the second change amount.

[0098] If the second amount of change exceeds the threshold value, the determining means 152 determines that a displacement abnormality has occurred in the structure (step S205). In this manner, the determining means 152 determines whether or not the distance between the position P1 where the first unit 110 is installed and the position P2 where the second unit 120 is installed is abnormal by comparing the value based on the second amount of change in the distance between the first unit 110 and the second unit 120 at the second time point with the threshold value.

[0099] The determination means 152 determines whether or not a displacement abnormality has occurred in the structure by using a threshold value set based on the first change amount and the first temperature measured in advance in the device itself. Therefore, the determination means 152 can determine whether or not a displacement abnormality has occurred in the structure with high accuracy.

[0100] Next, the transmission means 153 outputs the displacement anomaly information by transmitting it to the information processing device 200 via the first communication device 117 (step S206), and the process proceeds to step S208. The displacement anomaly information is an example of information related to the determination result by the determination means 152. This displacement anomaly information includes the device ID of the measuring device 100 and the most recent predetermined number of movement amounts (e.g., 10). This allows the structure manager to check the state of the structure immediately before the occurrence of the displacement anomaly, and to more accurately grasp the situation of the structure.

[0101] On the other hand, if the second change amount does not exceed the threshold value, the determination means 152 determines that no displacement abnormality has occurred in the structure (step S207), and proceeds to step S208 without transmitting the displacement abnormality information. Note that even if the second change amount calculated this time does not exceed the threshold value, if the second change amount calculated within the previous predetermined number of times exceeded the threshold value, the transmission means 153 may transmit the displacement abnormality information to the information processing device 200. This displacement abnormality information includes the device ID of the measuring device 100 and the latest movement amount. This allows the structure manager to check the state of the structure after the displacement abnormality has occurred, and to more accurately grasp the situation of the structure.

[0102] Next, the first acquisition means 151 associates the current date and time, temperature, amount of movement, and tilt acquired in step S202 with each other and stores them in the first storage device 140 (step S208). That is, the first acquisition means 151 stores each piece of information in the first storage device 140 regardless of whether a displacement abnormality has occurred. When a displacement abnormality occurs, this information is retroactively read out and transmitted to the information processing device 200 as displacement abnormality information.

[0103] Next, the first acquisition means 151 determines whether the second interval has elapsed (step S209). The second interval is preset to an interval (for example, 24 hours) at which regular communication with the information processing device 200 should be performed. If the second interval has not yet elapsed, the first acquisition means 151 returns the process to step S201.

[0104] On the other hand, if the second interval has elapsed, the transmitting means 153 transmits the measurement information to the information processing device 200 via the first communication device 117 (step S210). The measurement information includes a set of the current date and time, the temperature, and the movement amount that have been stored in step S208 and have not yet been transmitted to the information processing device 200.

[0105] Next, the first acquisition means 151 judges whether or not the determination parameter has been received from the information processing device 200 (step S211). If the determination parameter has been received, the first acquisition means 151 returns the process to step S201.

[0106] On the other hand, if the judgment parameter has not been received, the first acquisition means 151 acquires the judgment parameter from the information processing device 200 and stores it in the first storage device 140 (step S212), and returns the process to step S201. The first acquisition means 151 transmits an inquiry signal to the information processing device 200 via the first communication device 117, inquiring whether or not the judgment parameter for the own device is stored in the information processing device 200. The inquiry signal includes the device ID of the own device. When the control means 221 of the information processing device 200 receives an inquiry signal from the measuring device 100 via the second communication device 203, it determines whether or not the judgment parameter is stored in the second storage device 210 in association with the device ID included in the inquiry signal. The control means 221 transmits a response signal indicating whether or not the judgment parameter is stored to the measuring device 100 via the second communication device 203. The first acquisition means 151 receives a response signal from the information processing device 200 via the first communication device 117, and determines whether or not a determination parameter for the own device is stored in the information processing device 200 based on the received response signal. If a determination parameter for the own device is not stored in the information processing device 200, the first acquisition means 151 returns the process to step S201. On the other hand, if a determination parameter for the own device is stored in the information processing device 200, the first acquisition means 151 transmits a parameter request signal to the information processing device 200 via the first communication device 117, and receives and acquires the determination parameter from the information processing device 200 via the first communication device 117. This parameter request signal includes the device ID of the own device.

[0107] 6 periodically (e.g., once a month) even while the measuring device 100 is in operation, the information processing device 200 may create (update) judgment parameters and transmit them to the measuring device 100 for updating. This allows the monitoring system 1 to always use appropriate judgment parameters according to the latest environment of the measuring device 100 to accurately judge whether or not a displacement abnormality has occurred in the structure.

[0108] As described above, the monitoring system 1 sets a threshold value for comparison with a value based on the second change amount during operation, based on the moving average value of the first change amount and the moving average value of the first temperature in a predetermined period. The separation distance in a gap such as a gap in a structure such as a bridge changes due to the influence of daily expansion and contraction of the structure due to temperature change, etc. The influence of such expansion and contraction may be greater than the influence of the deformation of the structure itself (structural change that does not occur daily, such as bending of bridge girders). In addition, the separation distance in such a gap in a structure also differs depending on the characteristics of the scale (size), material, or structure, etc. of the structure. The monitoring system 1 can clarify the relationship between the change amount of distance and temperature by smoothing the change amount of distance and temperature measured by each measuring device 100. The monitoring system 1 determines whether or not the distance between the position P1 where the first unit 110 is installed and the position P2 where the second unit 120 is installed is abnormal, taking into account the relationship between the change amount of distance and temperature. This enables the monitoring system 1 to accurately determine whether the distance between the position P1 where the first unit 110 is installed and the position P2 where the second unit 120 is installed is abnormal, regardless of the temperature in the environment in which the measuring device 100 is installed or the characteristics of the structure being measured.

[0109] The transmission means 153 of the measurement device 100 may further transmit the battery voltage of the battery 115, the radio wave intensity received by the first communication device 117, and / or the tilt of the first unit 110 to the information processing device 200 as the measurement information. In this case, the control means 221 of the information processing device 200 determines that a battery abnormality has occurred when the battery voltage included in the received measurement information is less than a preset voltage lower limit value or greater than a preset voltage upper limit value. Furthermore, the control means 221 determines that a radio wave abnormality has occurred when the radio wave intensity received by the first communication device 117 included in the received measurement information is less than a preset radio wave intensity lower limit value or greater than a preset radio wave intensity upper limit value. Furthermore, the control means 221 determines that a tilt abnormality has occurred when the tilt of the first unit 110 included in the received measurement information is less than a preset tilt lower limit value or greater than a preset tilt upper limit value. When it is determined that an abnormality has occurred, the notification means 225 sends an equipment abnormality notification (e.g., email) indicating the occurrence of the equipment abnormality to the contact information of the equipment administrator (e.g., the email address of the equipment administrator that can be viewed by the equipment administrator on the equipment administrator terminal 400). The equipment administrator can quickly replace the target measuring device 100 by viewing the equipment abnormality notification using the equipment administrator terminal 400.

[0110] A monitoring system 1 according to another embodiment will be described below. In the monitoring system 1 according to this embodiment, the first processing circuit 150 of the measuring device 100 has a part of the setting means 224. The processing of the setting means 224 executed by the first processing circuit 150 is a threshold setting processing.

[0111] In the management process executed in this embodiment, the processes of steps S107 and S109 in Fig. 6 are omitted. In addition, in step S111 in Fig. 6, the information processing device 200 transmits the relational equation and the intraday variation range as the determination parameters, and in step S212 in Fig. 10, the measurement device 100 receives the relational equation and the intraday variation range as the determination parameters.

[0112] In addition, in the measurement process performed in this embodiment, in step S204 of FIG. 10, the setting means 224 sets a threshold value based on the above-mentioned relational expression, the average value of the second temperature, the daily change range and the margin, and the determination means 152 compares the second change amount (movement amount) with the threshold value.

[0113] First, the setting means 224 reads out the second temperature for a predetermined period in the past from the first storage device 140. Next, the setting means 224 calculates the average value of the read out second temperature and the current second temperature acquired in step S202. The predetermined period is set to the same period as the predetermined period in which the moving average value of the first change amount was calculated. The predetermined period may be set to a period shorter than the predetermined period in which the moving average value of the first change amount was calculated. Next, the setting means 224 calculates the amount of change (r(k)) calculated from the average value (k) of the second temperature at each second time point using the relational expression (r(k)=a·k+b). The calculated amount of change is a reference value for a threshold value taking into account seasonal fluctuations.

[0114] Next, the setting means 224 calculates the temperature margin by substituting a predetermined temperature into the relational expression. The setting means 224 then subtracts the above-mentioned intraday variation range, the calculated temperature margin, and the preset bridge design margin and measurement accuracy margin from the value obtained by substituting the average value of the second temperature into the relational expression to set a lower limit value. The setting means 224 also sets an upper limit value by adding the above-mentioned intraday variation range, the calculated temperature margin, and the preset bridge design margin and measurement accuracy margin to the value obtained by substituting the average value of the second temperature into the relational expression.

[0115] Next, the determination means 152 determines whether the second change amount has exceeded a threshold value included in the determination parameters. For example, when the second change amount is less than the lower limit value or greater than the upper limit value, the determination means 152 determines that the second change amount has exceeded the threshold value. On the other hand, when the second change amount is equal to or greater than the lower limit value and equal to or less than the upper limit value, the determination means 152 determines that the correction value has not exceeded the threshold value. When the second change amount has exceeded the threshold value, the determination means 152 determines in step S205 that a displacement abnormality has occurred in the structure. On the other hand, when the second change amount has not exceeded the threshold value, the determination means 152 determines in step S207 that a displacement abnormality has not occurred in the structure.

[0116] The setting means 224 determines whether or not a predetermined period has elapsed, and does not calculate a threshold value until the predetermined period has elapsed. Also, the determination means 152 does not determine the presence or absence of a displacement abnormality while the threshold value is not calculated. When the predetermined period has elapsed, the setting means 224 calculates the threshold value by calculating an average value during the predetermined period, and when the threshold value is calculated, the determination means 152 compares the second amount of change with the threshold value.

[0117] The determination means 152 may use the average value of the second change amount instead of the second change amount to determine whether the second change amount has exceeded the threshold value. The average value of the second change amount is the average value of the second change amount in a consecutive predetermined period among the plurality of second time points. The predetermined period is set to the same period as the predetermined period in which the average value of the second temperature is calculated. The predetermined period may be set to a period different from the predetermined period in which the moving average value of the second temperature is calculated. In this case, the threshold value is set so as not to include the intraday change range. That is, the lower limit value is set to a value obtained by subtracting the temperature margin, the bridge design margin, and the measurement accuracy margin from the change amount calculated from the relational expression and the average value of the second temperature, and the upper limit value is set to a value obtained by adding the temperature margin, the bridge design margin, and the measurement accuracy margin to the change amount calculated from the relational expression and the average value of the second temperature. The determination means 152 determines that the average value of the second change amount has exceeded the threshold value when the average value of the second change amount at each second time point is less than the lower limit value or is greater than the upper limit value. On the other hand, when the average value of the second amounts of change is equal to or greater than the lower limit and equal to or less than the upper limit, the determining means 152 determines that the average value of the second amounts of change does not exceed the threshold value.

[0118] In this way, the determination means 152 determines whether or not the distance between the position P1 where the first unit 110 is installed and the position P2 where the second unit 120 is installed is abnormal by comparing the second change amount or the average value of the second change amount of the distance between the first unit 110 and the second unit 120 at the second time point with the threshold value. The second change amount or the average value of the second change amount is an example of a value based on the second change amount. In particular, the determination means 152 determines whether or not the distance between the position P1 where the first unit 110 is installed and the position P2 where the second unit 120 is installed is abnormal by comparing the second change amount or the average value of the second change amount with the threshold value calculated using the change amount calculated from the average value of the second temperature at the second time point by the relational expression. By considering the temperature at the measuring device 100, the monitoring system 1 can accurately determine whether or not the distance between the position P1 where the first unit 110 is installed and the position P2 where the second unit 120 is installed is abnormal.

[0119] The determination means 152 calculates the threshold value using a relational expression set based on the first amount of change and the first temperature measured in advance in the own device and the average value of the second temperature, thereby making it possible to appropriately set the threshold value according to the environment in which the own device is installed, particularly the temperature of the own device. Furthermore, the determination means 152 compares the second amount of change or the average value of the second amount of change with a threshold value appropriately set according to the temperature of the own device to determine whether or not a displacement abnormality has occurred in the structure. Therefore, the determination means 152 can determine with high accuracy whether or not a displacement abnormality has occurred in the structure.

[0120] As described above, even when the monitoring system 1 sets the threshold value at each second point in time using a relational equation, it is possible to accurately determine whether or not the distance between the position P1 where the first unit 110 is installed and the position P2 where the second unit 120 is installed is abnormal.

[0121] Although the preferred embodiments have been described above, the embodiments are not limited to these. For example, the division of functions between the measurement device 100 and the information processing device 200 is not limited to the above example, and the arrangement of each unit of the measurement device 100 and the information processing device 200 in either the measurement device 100 or the information processing device 200 can be changed as appropriate.

[0122] It should be understood by those skilled in the art that various changes, substitutions, and modifications can be made to the present invention without departing from the spirit and scope of the present invention. For example, the above-mentioned embodiments and modifications may be appropriately combined within the scope of the present invention. [Explanation of symbols]

[0123] 1. Surveillance System 100 Measuring Equipment 110 Unit 1 117 First communication device 120 Unit 2 152 Judgment means 200 Information processing device 203 Second communication device 223 Calculation Method 224 Setting method

Claims

1. a setting means for setting a threshold value based on a moving average value of a first amount of change in a distance between a first unit installed at a first position and a second unit installed at a second position separated from the first position at a plurality of first time points, and a moving average value of a first temperature at the plurality of first time points; a determination means for determining whether or not the distance between the first position and the second position is abnormal by comparing a value based on a second amount of change in the distance between the first unit and the second unit at a second time point with the threshold value; an output unit that outputs information regarding a result of the determination by the determination means; A monitoring system comprising:

2. a calculation means for calculating a relational expression indicating a relationship between the moving average value of the first change amount at the plurality of first time points and the moving average value of the first temperature at the plurality of first time points by performing a linear regression analysis or a multiple regression analysis on the moving average value of the first change amount at the plurality of first time points and the moving average value of the first temperature at the plurality of first time points, 2. The monitoring system according to claim 1, wherein said setting means sets said threshold value further based on said relational expression.

3. 3. The monitoring system according to claim 1, wherein the setting means calculates an annual minimum or maximum amount of change in the first amount of change based on an annual maximum or minimum temperature of the first temperature, and sets the threshold value based on an annual minimum or maximum amount of change in the first amount of change.

4. The plurality of first time points spans a plurality of days, 3. The monitoring system according to claim 1, wherein the setting means calculates a daily variation range that is a maximum value among daily variation ranges of the first change amount, and sets the threshold value based on the daily variation range.

5. the setting means sets the threshold value based on the relational expression and an average value of the second temperatures at a plurality of the second time points; 3. The monitoring system according to claim 2, wherein the determination means determines whether or not the distance between the first position and the second position is abnormal by comparing the second change amount or an average value of the second change amount with the threshold value.

6. setting a threshold value based on a moving average value of a first amount of change in a distance between a first unit installed at a first position and a second unit installed at a second position separated from the first position at a plurality of first time points, and a moving average value of a first temperature at the plurality of first time points; determining whether or not the distance between the first position and the second position is abnormal by comparing a value based on a second amount of change in the distance between the first unit and the second unit at a second time point with the threshold value; Output information about the judgment result, A monitoring method comprising:

7. A program for controlling a measurement device, setting a threshold value based on a moving average value of a first amount of change in a distance between a first unit installed at a first position and a second unit installed at a second position separated from the first position at a plurality of first time points, and a moving average value of a first temperature at the plurality of first time points; determining whether or not the distance between the first position and the second position is abnormal by comparing a value based on a second amount of change in the distance between the first unit and the second unit at a second time point with the threshold value; Output information about the judgment result, The program causing the measuring device to execute the above steps.

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