Structure monitoring system

Abstract

To reduce power consumption in a structure monitoring system.SOLUTION: A structure monitoring system 100 for monitoring an internally illuminated signboard 10 provided outdoors includes: a vibration sensor 50 for measuring a vibration of the internally illuminated signboard 10 from its acceleration for a predetermined time; and a determination section 73 for determining structural deterioration of the internally illuminated signboard 10 on the basis of a measurement result by the vibration sensor 50. The determination section 73 determines the structural deterioration of the internally illuminated signboard 10 from a correlation between determination acceleration which is plurally set and the number of times of vibration as the number of times the acceleration of the internally illuminated signboard 10 is the determination acceleration or more within the predetermined time in the measurement result.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a structure monitoring system. [Background technology]

[0002] Patent Document 1 discloses an interiorly illuminated structure that is installed outdoors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-20913 A Summary of the Invention [Problem to be solved by the invention]

[0004] When an internally illuminated structure such as that described in Patent Document 1 is installed outdoors for a long period of time, structural deterioration occurs, such as component parts becoming loose. For this reason, a monitoring system is sometimes installed to monitor structural deterioration. The monitoring system uses a built-in power source such as a battery so that structural deterioration can be monitored even during a power outage, and uses a sensor to measure vibration data within the internally illuminated structure, transmits the data to an analysis device, and analyzes it. To determine structural deterioration, FFT analysis or the like is generally performed based on the vibration data.

[0005] However, in this case, the amount of data communication from the sensors and analysis devices is large, and the power consumption of the monitoring system is high. In an indoor-illuminated structure installed outdoors, replacing the built-in power supply of the monitoring system is time-consuming due to the need to work at height, so it is desirable for the power consumption of the monitoring system to be low.

[0006] The present invention has been made in consideration of the above problems, and has an object to reduce the power consumption of a structure monitoring system. [Means for solving the problem]

[0007] The present invention is a structure monitoring system that monitors a structure installed outdoors, and includes a vibration measurement unit that measures the vibration of the structure from acceleration for a predetermined period of time, and a judgment unit that judges structural deterioration of the structure based on the measurement results of the vibration measurement unit, and is characterized in that the judgment unit judges structural deterioration of the structure from the correlation between multiple judgment accelerations set in the measurement results and the vibration count, which is the number of times the acceleration of the structure becomes equal to or greater than the judgment acceleration within a predetermined period of time. Effect of the Invention

[0008] According to the present invention, the power consumption of a structure monitoring system can be reduced. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view of an interiorly illuminated structure to which a structure monitoring system according to an embodiment of the present invention is applied. [Diagram 2] FIG. 4 is a perspective view showing the shape of a frame body. [Diagram 3] 1 is a configuration diagram of a structure monitoring system according to an embodiment of the present invention. [Figure 4] 1 is a logarithmic graph showing the measurement results of a vibration sensor of an internally illuminated signboard under normal conditions. [Diagram 5] 13 is a logarithmic graph showing the measurement results of the vibration sensor at each wind speed when an internally illuminated signboard is in a normal state. [Figure 6] 13 is a logarithmic graph showing the measurement results of a vibration sensor at each wind speed when an internally illuminated signboard is deteriorated. [Figure 7] 11 is a logarithmic graph showing a comparison of the vibration sensor measurement results at various wind speeds when an internally illuminated sign is in a normal state and when it is deteriorated. [Figure 8] 1 is a graph showing the correlation between a first deterioration determination value and a second deterioration determination value when an internally illuminated signboard is in a normal state and when it is in a deteriorated state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0011] First, a structure monitoring system 100 according to an embodiment of the present invention will be described with reference to Fig. 1 and Fig. 3. Fig. 1 is a perspective view of an internally illuminated signboard 10 as a structure to which the structure monitoring system 100 is applied, Fig. 2 is a perspective view showing the shape of a frame 12 described below, and Fig. 3 is a configuration diagram showing each device that constitutes the structure monitoring system 100. Note that Fig. 2 omits illustration of lighting equipment 20 and power supply unit 30 described below.

[0012] The structure monitoring system 100 is a system for monitoring structural deterioration of an internally illuminated signboard 10 installed outdoors. First, the internally illuminated signboard 10 will be described.

[0013] As shown in FIG. 1, internally illuminated signboard 10 has a pair of panel panels 11 on which information such as advertisements, store names, etc. are displayed, a frame body 12 (see FIG. 2) that holds panel panels 11, a pair of side panels 13 provided on frame body 12, a top panel 14 and a bottom panel 15 provided on frame body 12, lighting equipment 20 provided in the internal space surrounded by panel 11, frame body 12, side panels 13, top panel 14, and bottom panel 15, and a power supply unit 30 that supplies power to lighting equipment 20.

[0014] As shown in FIG. 2, the frame body 12 is formed so as to extend along the sides of a rectangular parallelepiped. The frame body 12 is provided with a pair of face plates 11, and a pair of side plates 13 are provided between the pair of face plates 11. The frame body 12 is also provided with a top plate 14 above the face plate 11 and the side plates 13, and a bottom plate 15 below the face plate 11 and the side plates 13. The face plate 11, the side plates 13, the top plate 14, and the bottom plate 15 are fixed to the frame body 12 by fixing members (not shown) such as bolts as shown by the arrows in FIG. 2. The frame body 12 is made of iron, and the top plate 14 and the bottom plate 15 are made of metal such as iron or aluminum alloy, but the materials of the frame body 12, the top plate 14, and the bottom plate 15 are not limited to the above, and may be made of plastic, or may be made of a combination of metal and plastic. One end of a support 16 is connected to the bottom plate 15, and the internally illuminated signboard 10 is supported on the ground (installation surface) by the support 16. Further, the frame 12 is provided with an attachment portion 12a so as to cross an area where one of the side plates 13 is provided, and a sensor box 40 is provided on the attachment portion 12a. A vibration sensor 50 and a transmission unit 60, which will be described later, are housed in the sensor box 40.

[0015] As shown in FIG. 1, face plate 11 is made of a light-transmitting plastic, for example a resin-based plate material such as acrylic or polycarbonate, and has colored letters and figures printed on its surface.

[0016] The lighting devices 20 are LEDs (Light Emitting Diodes) or fluorescent lamps that emit light using power supplied from the power supply unit 30. The lighting devices 20 are provided on the bottom plate 15. The lighting devices 20 illuminate the panel 11 from inside the internally illuminated signboard 10, making the characters and figures on the panel 11 easy to see even at night. The lighting devices 20 may be provided in a dispersed manner within the internally illuminated signboard 10, rather than being provided in one place therein. Furthermore, the power supply unit 30 does not need to be provided within the internally illuminated signboard 10, and from the viewpoint of maintenance, it may be provided, for example, in a box provided below the support pole 16.

[0017] Next, the structure monitoring system 100 will be described with reference to FIG.

[0018] The structure monitoring system 100 includes a vibration sensor 50 as a vibration measuring unit that measures vibrations of the internally illuminated sign 10, and a monitoring unit 70 that receives the measurement results of the vibration sensor 50 and monitors structural deterioration of the internally illuminated sign 10. In this embodiment, the vibration sensor 50 is provided in a sensor box 40 inside the internally illuminated sign 10, and the monitoring unit 70 is provided outside the internally illuminated sign 10. The vibration sensor 50 and the monitoring unit 70 communicate with each other via wireless communication. The monitoring unit 70 may also be provided inside the internally illuminated sign 10.

[0019] In this embodiment, the vibration sensor 50 is an acceleration sensor that measures a resultant acceleration of three axes of the X-axis, Y-axis, and Z-axis. The vibration sensor 50 is not limited to an acceleration sensor that measures the acceleration of three axes. The vibration sensor 50 operates on a built-in power source (not shown), such as a battery, different from the power source unit 30 so that the deterioration of the structure can be monitored even during a power outage. The vibration sensor 50 measures the vibration of the interiorly illuminated signboard 10 from the acceleration for a predetermined time. Specifically, the vibration sensor 50 performs an operation of acquiring the acceleration of the interiorly illuminated signboard 10 at a predetermined time interval (for example, 10 ms) for a predetermined time period (for example, 10 minutes). The vibration sensor 50 performs the above series of measurements multiple times at a predetermined time interval (for example, every hour). The detection value (measurement result) of the vibration sensor 50 is transmitted to the monitoring unit 70 through the transmission unit 60. In this embodiment, the vibration sensor 50 and the transmission unit 60 are provided in a sensor box 40 arranged on the mounting portion 12a of the frame body 12, and measure the vibration of the interiorly illuminated signboard 10. Specifically, the vibration sensor 50 measures the vibration of the frame 12 caused by an external force such as wind.

[0020] The transmitting unit 60 is a wireless data communication device capable of transmitting the detection value of the vibration sensor 50 to the monitoring unit 70, and specifically, for example, SIGFOX (registered trademark) with low power consumption. The transmitting unit 60 is not limited to SIGFOX, and may be any standard wireless communication device capable of transmitting data to the monitoring unit 70 via the communication network 90, which is an Internet line, and may be LPWA. However, it is preferable to use SIGFOX from the viewpoint of reducing power consumption. The transmitting unit 60 may be a wired communication device connected to the communication network 90 by wire. The transmitting unit 60 has a control unit (not shown) that controls the time interval and the time at which the vibration sensor 50 performs detection, and also controls the time interval and the time at which the transmitting unit 60 transmits data.

[0021] The monitoring unit 70 has a receiving unit 71 that receives data transmitted via the transmitting unit 60 (detection value of the vibration sensor 50), a memory unit 72 in which the data received by the receiving unit 71 and the like are stored, a judgment unit 73 that judges structural deterioration of the internally illuminated signboard 10 based on the data stored in the memory unit 72, and an alarm unit 74 that reports the judgment result of the judgment unit 73.

[0022] The monitoring unit 70 is composed of a computer equipped with a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an I / O interface (Input / Output Interface), etc. The RAM stores data for CPU processing, the ROM stores the CPU's control program and the like in advance, and the I / O interface is used for inputting and outputting information to and from connected devices. The structural deterioration of the internally illuminated sign 10 is determined by operating the CPU, RAM, etc. according to the program stored in the ROM.

[0023] The determination unit 73 represents each function of the monitoring unit 70 as a virtual unit, and does not mean that it exists physically. The monitoring unit 70 may be a server such as a cloud server, in which case the structural deterioration of the interiorly illuminated signboard 10 is determined by an application on the server, and the determination result can be shared on the server.

[0024] The structure monitoring system 100 measures vibrations of components that are part of the structure, and judges structural deterioration such as components inside the structure coming loose. In the present embodiment, as an example, the structure monitoring system 100 measures vibrations of the frame 12, and judges structural deterioration of the internally illuminated sign 10 such as the face panel 11, side panels 13, top panel 14, and bottom panel 15 coming loose from the frame 12 due to loosening or corrosion of the fixing members.

[0025] This time, in order to determine the structural deterioration of the internally illuminated sign 10, numerous vibration measurements were actually performed on the internally illuminated sign 10 in advance. As a result, it was confirmed that there is a difference in the vibration measurement results between when there is no structural deterioration of the internally illuminated sign 10 (hereinafter also referred to as "normal") and when there is structural deterioration (hereinafter also referred to as "degraded"). Below, the results of measuring the vibration of the internally illuminated sign 10 when it is normal and when it is deteriorated are described.

[0026] Figure 4 shows the relationship between acceleration and the number of vibrations, which is the number of times the detected value of the vibration sensor 50 becomes equal to or greater than that acceleration, during normal operation of the internal illumination signboard 10. In Figure 4, the horizontal axis (X-axis) represents acceleration and the vertical axis (Y-axis) represents the number of vibrations, and the relationship is schematically shown as a logarithmic graph. Note that Figure 4 shows the results of one measurement by the vibration sensor 50 over a predetermined time. In Figure 4 and Figures 5-7 described later, the numerical values of acceleration are shown with a reference value of 1G, and the number of vibrations is the total number of times (cumulative frequency), and the numerical values are for example only. The smaller the acceleration, the greater the number of vibrations, and the larger the acceleration, the smaller the number of vibrations. In this graph, it was confirmed that the graph includes a curve in the region where the acceleration is less than a specific acceleration Z, and the graph becomes approximately linear in the region where the acceleration is greater than or equal to acceleration Z. Hereinafter, the region where the graph of less than acceleration Z includes a curve will also be referred to as the "low acceleration region", and the region where the graph of greater than or equal to acceleration Z becomes approximately linear will also be referred to as the "high acceleration region".

[0027] Figure 5 schematically shows the relationship between acceleration and the number of vibrations when the wind speed is high and low during normal operation of the internal illumination signboard 10. Note that Figures 5 and Figure 6 described later show the results of one measurement by the vibration sensor 50 over a predetermined time when the wind speed is high and low, respectively. When the wind speed is high, the internal illumination signboard 10 sways more than when the wind speed is low. Therefore, it was confirmed that when the wind speed is high, the number of vibrations at a large acceleration is greater than when the wind speed is low. Also, it was confirmed that the slopes in the high acceleration region are approximately the same regardless of the wind speed. In other words, as shown in Figure 5, at predetermined accelerations A and B (A < B) in the high acceleration region, the ratio of the number of vibrations Na at acceleration A to the number of vibrations Nb at acceleration B is approximately the same when the wind speed is high (Nb2 / Na2) and low (Nb1 / Na1) (Nb1 / Na1 = Nb2 / Na2).

[0028] FIG. 6 schematically shows the relationship between acceleration and the number of vibrations when the internal illumination signboard 10 deteriorates, for the cases of high and low wind speeds. Even in this graph, as in the normal state, it was confirmed that in the low acceleration region below a specific acceleration Z´, the graph includes a curve, and in the high acceleration region of acceleration Z´ or more, the graph becomes substantially linear. Also, it was confirmed that as the wind speed increases, the number of vibrations at high accelerations increases, and regardless of the wind speed, the slopes in the high acceleration region are substantially the same. In other words, the ratio of the number of vibrations Na´ at acceleration A to the number of vibrations Nb´ at acceleration B is substantially the same for the case of high wind speed (Nb2´ / Na2´) and the case of low wind speed (Nb1´ / Na1´).

[0029] However, as shown in FIG. 7, when the internal illumination signboard 10 deteriorates, it was confirmed that the number of vibrations is larger than in the normal state, particularly in the region of large acceleration. Specifically, assuming that the number of vibrations in the normal state at predetermined accelerations C and D (C < D, see FIGS. 5 - 7) in the low acceleration region are Nc and Nd, and the number of vibrations during deterioration are Nc´ and Nd´, then regardless of the wind speed, Nc´ does not differ significantly from Nc. However, Na´, Nb´, and Nd´ became larger than Na, Nb, and Nd, respectively. Also, it was confirmed that the slopes of the logarithmic graphs in the high acceleration region are different between the normal state and the deteriorated state of the internal illumination signboard 10. Specifically, as shown in FIGS. 5 and 6, when the internal illumination signboard 10 deteriorates, the absolute value of the slope in the high acceleration region is smaller than in the normal state. In other words, the ratio of the number of vibrations at acceleration A to the number of vibrations at acceleration B is larger during the deterioration of the internal illumination signboard 10 (Nb´ / Na´) than in the normal state (Nb / Na).

[0030] This is because when structural deterioration occurs and the front panel 11, side plates 13, top plate 14, and bottom plate 15 are about to come off the frame body 12, when the internal illumination signboard 10 sways under the influence of wind, the loosening part sways greatly. Also, when this part sways, it collides with the frame body 12, causing the frame body 12 to vibrate more than when it is affected by wind. Therefore, when the internal illumination signboard 10 deteriorates, the number of vibrations at accelerations larger than in the normal state increases, and the absolute value of the slope of the graph becomes smaller.

[0031] FIG. 8 is a schematic diagram showing the relationship between the ratio (Nd / Nc) of the vibration frequencies Nc and Nd in the low acceleration region and the ratio (Nb / Na) of the vibration frequencies Na and Nb in the high acceleration region when the internally illuminated sign 10 is normal and when it is deteriorated. Note that FIG. 8 also shows measurement results other than those shown in the graphs of FIGS. 5 to 7. In this graph, by looking at the correlation between the vibration frequencies at points of low acceleration and the vibration frequencies at points of high acceleration, it was confirmed that there is a difference between the normal state and the deteriorated state. Specifically, as described above, when the internally illuminated sign 10 is normal, Nb / Na is small and Nd / Nc is large. On the other hand, when the internally illuminated sign 10 is deteriorated, Nb / Na is large and Nd / Nc is small compared to the normal state. Therefore, if Nb / Na is the first deterioration judgment value J1 and Nd / Nc is the second deterioration judgment value J2, it was confirmed that under normal conditions, the first deterioration judgment value J1 is small and the second deterioration judgment value J2 is large, and under deteriorated conditions, the first deterioration judgment value J1 is large and the second deterioration judgment value J2 is small.

[0032] Therefore, in this embodiment, the above results are utilized to determine structural deterioration of the internally illuminated sign 10 based on the first deterioration determination value J1 and the second deterioration determination value J2. Specifically, as shown in Fig. 8, structural deterioration of the internally illuminated sign 10 is determined based on whether the first deterioration determination value J1 and the second deterioration determination value J2 are within a preset deterioration determination region.

[0033] Next, the determination of structural deterioration of the internally illuminated signboard 10 by the structure monitoring system 100 will be described.

[0034] The determination unit 73 of the structure monitoring system 100 determines structural deterioration of the internally illuminated signboard 10 from the correlation between a plurality of set determination accelerations and the number of vibrations at the determination accelerations.

[0035] Specifically, the memory unit 72 stores the determined accelerations in advance. The determined accelerations include acceleration A as a first determined acceleration, acceleration B as a second determined acceleration, acceleration C as a third determined acceleration, and acceleration D as a fourth determined acceleration. The determined accelerations are obtained by taking the measurement results of the vibration sensor 50 of the interiorly illuminated signboard 10 and a signboard having a shape similar to that of the interiorly illuminated signboard 10 in normal and deteriorated states in advance, and setting the accelerations A and B so as to be in a high acceleration region, and setting the accelerations C and D so as to be in a low acceleration region. In other words, the accelerations A and B are set in a region where the logarithmic graphs shown in FIGS. 4 to 7 are approximately straight lines, and the accelerations C and D are set in a region where the logarithmic graphs shown in FIGS. 4 to 7 are curved lines.

[0036] Furthermore, the memory unit 72 stores in advance degradation judgment regions (numerical ranges) of the first degradation judgment value J1 (Nb / Na) and the second degradation judgment value J2 (Nd / Nc) for judging that structural degradation of the internally illuminated sign 10 has occurred. The degradation judgment region is set from the correlation between the first degradation judgment value J1 and the second degradation judgment value J2 as shown in FIG. 8 obtained from the measurement results of the vibration sensor 50 in normal and deteriorated states of the internally illuminated sign 10 and a signboard with a similar shape to the internally illuminated sign 10. Specifically, the numerical range of the first degradation judgment value J1 is set to a large value that can be obtained when the internally illuminated sign 10 is deteriorated, and the numerical range of the second degradation judgment value J2 is set to a small value that can be obtained when the internally illuminated sign 10 is deteriorated.

[0037] First, the determination unit 73 reads the detection value of the vibration sensor 50 stored in the memory unit 72 after the vibration sensor 50 has performed measurement for a predetermined time. Then, from the detection value, it calculates the vibration frequencies Na, Nb, Nc, and Nd at the accelerations A, B, C, and D, as well as the first deterioration judgment value J1 and the second deterioration judgment value J2. Then, it determines whether the first deterioration judgment value J1 and the second deterioration judgment value J2 are both included in the deterioration judgment region (in other words, whether the plots of the first deterioration judgment value J1 and the second deterioration judgment value J2 shown in FIG. 8 are included in the deterioration judgment region). If the first deterioration judgment value J1 and the second deterioration judgment value J2 are included in the deterioration judgment region, the determination unit 73 determines that structural deterioration of the internally illuminated signboard 10 has occurred, and various information such as the occurrence of deterioration and the installation position and appearance of the internally illuminated signboard 10 is notified via the notification unit 74. By having an operator perform maintenance on an internally illuminated sign 10 that has deteriorated based on the contents of the notification, it is possible to prevent the internally illuminated sign 10 from being left unattended without the deterioration being noticed. If the first deterioration determination value J1 and the second deterioration determination value J2 are not included in the deterioration determination range, the determination unit 73 determines that there is no structural deterioration of the internally illuminated sign 10 and terminates the process, and when the vibration sensor 50 measures again for a predetermined period of time, it repeats the above determination.

[0038] In this manner, the method of determining structural deterioration of the internally illuminated signboard 10 of this embodiment calculates a first deterioration determination value J1 by dividing the vibration frequency Nb by the vibration frequency Na in the measurement results of the vibration sensor 50, calculates a second deterioration determination value J2 by ​​dividing the vibration frequency Nd by the vibration frequency Nc, and determines whether the magnitude of the first deterioration determination value J1 relative to the second deterioration determination value J2 is included in a predetermined deterioration determination range. Moreover, the above-mentioned determination method is realized by the determination unit 73 executing an information processing program read from the storage unit 72.

[0039] As described above, the structure monitoring system 100 determines structural deterioration of the internally illuminated sign 10 from the correlation between the determined acceleration and the number of vibrations. Therefore, the vibration sensor 50 only transmits the detected value, and the determination unit 73 can determine structural deterioration of the internally illuminated sign 10 with simple calculations and less processing without performing FFT analysis or the like. Furthermore, compared to when FFT analysis or the like is performed, structural deterioration of the internally illuminated sign 10 can be determined with less data, so the amount of data communication required by the vibration sensor 50 and the monitoring unit 70 is reduced. Therefore, the power consumption of the structure monitoring system 100 can be reduced.

[0040] 8, the structure monitoring system 100 judges the structural deterioration of the internally illuminated sign 10 based on the magnitude of the first deterioration judgment value J1 relative to the second deterioration judgment value J2. Therefore, by collecting the measurement results of the vibration sensor 50 in advance of the internally illuminated sign 10 or a signboard with a similar shape to the internally illuminated sign 10 when normal and when deteriorated, and setting a deterioration judgment area, it is possible to judge the structural deterioration of the internally illuminated sign 10 with a small amount of data communication and a small amount of processing. Therefore, the power consumption of the structure monitoring system 100 can be reduced.

[0041] Furthermore, because an internally illuminated sign 10 is installed outdoors and sways due to disturbances such as wind, the frequency of vibration does not follow a normal distribution, unlike indoor structures, and it is difficult to accurately determine structural deterioration using an index such as 1σ. However, because the structure monitoring system 100 determines structural deterioration of an internally illuminated sign 10 based on the magnitude of the first deterioration determination value J1 relative to the second deterioration determination value J2 as described above, structural deterioration can be accurately determined even for an internally illuminated sign 10 installed outdoors.

[0042] Note that the determination unit 73 may determine the structural deterioration of the internally illuminated sign 10 not from the results of the vibration sensor 50 over a predetermined time period, but from the measurement results of a single measurement performed multiple times over a predetermined time period by the vibration sensor 50. For example, the determination unit 73 may determine the structural deterioration of the internally illuminated sign 10 from the average value of the first deterioration determination value J1 and the second deterioration determination value J2 calculated from the results of multiple measurements by the vibration sensor 50.

[0043] According to the above embodiment, the following effects are achieved.

[0044] In the structure monitoring system 100, structural deterioration of the internally illuminated sign 10 is determined from the correlation between the determined acceleration and the number of vibrations. Therefore, the vibration sensor 50 only transmits the detected value, and the determination unit 73 can determine structural deterioration of the internally illuminated sign 10 with simple calculations and less processing without performing FFT analysis or the like. Furthermore, because structural deterioration of the internally illuminated sign 10 can be determined with less data compared to when FFT analysis or the like is performed, the amount of data communication by the vibration sensor 50 and the monitoring unit 70 is reduced, and the power consumption of the structure monitoring system 100 can be reduced.

[0045] Next, modified examples of the present embodiment will be described. The following modified examples are also within the scope of the present invention, and it is possible to combine the following modified examples with each of the configurations of the above embodiment, or to combine the following modified examples with each other.

[0046] <Variation 1> In the above embodiment, the determination unit 73 determines the structural deterioration of the internally illuminated signboard 10 based on the first deterioration determination value J1 and the second deterioration determination value J2. By using not only the first deterioration determination value J1 (in other words, the slope of the logarithmic graph in the high acceleration region) but also the second deterioration determination value J2 and determining the structural deterioration of the internally illuminated signboard 10 from the plot of the first deterioration determination value J1 and the second deterioration determination value J2 as shown in FIG. 8, the structural deterioration can be determined more accurately. Without being limited to this, the determination unit 73 may determine the structural deterioration of the internally illuminated signboard 10 based only on the first deterioration determination value J1. In other words, the structure monitoring system 100 may determine the structural deterioration of the internally illuminated signboard 10 based on the slope between two points on a double logarithmic graph of the determined acceleration and the vibration frequency (specifically, the slope between the vibration frequency Na at acceleration A and the vibration frequency Nb at acceleration B). In this case, only the numerical range of the first deterioration determination value J1 is set as the deterioration determination region, and a large value that is obtained when the internally illuminated signboard 10 is deteriorated is set.

[0047] Furthermore, when the determination unit 73 determines the structural deterioration of the internally illuminated signboard 10 based only on the first deterioration determination value J1, the determination unit 73 may determine the structural deterioration of the internally illuminated signboard 10 based on a representative value of the first deterioration determination value J1 calculated from the results of multiple measurements by the vibration sensor 50. The representative value is a moving average value or a moving median value of the first deterioration determination value J1. Specifically, the moving average value or the moving median value of the first deterioration determination value J1 for one month may be calculated, and the structural deterioration of the internally illuminated signboard 10 may be determined from the moving average value or the moving median value. This makes it possible to mitigate the influence of the wind speed, etc., which varies with each measurement, and to more accurately determine the structural deterioration of the internally illuminated signboard 10. Furthermore, when the vibration frequency Na and the vibration frequency Nb are 0, the determination unit 73 may not use the corresponding first deterioration determination value J1 to calculate the moving average value or the moving median value of the first deterioration determination value J1. In other words, when the vibration count Na and the vibration count Nb are 0, the judgment unit 73 may calculate the moving average value and the moving median value of the first deterioration judgment value J1 by using the corresponding first deterioration judgment value J1 as blank (no data). As a result of actually performing vibration measurements on many internally illuminated signs 10, it was confirmed that the accuracy of judging the structural deterioration of the internally illuminated sign 10 is reduced by data in which the vibration count Na and the vibration count Nb are 0. Therefore, by calculating the moving average value and the moving median value of the first deterioration judgment value J1 by using the first deterioration judgment value J1 as blank, the accuracy of judging the structural deterioration of the internally illuminated sign 10 can be improved.

[0048] <Variation 2> In the above embodiment, the determination unit 73 determines the structural deterioration of the internally illuminated signboard 10 from the measurement results of the vibration sensor 50. In this case, the determination unit 73 may determine the structural deterioration of the internally illuminated signboard 10 by referring only to data in which the number of vibrations at a predetermined large acceleration (e.g., acceleration B) is equal to or greater than a predetermined number. If the predetermined time for the vibration sensor 50 to measure vibrations is short, an error is likely to occur in the number of small vibrations, such as a few, and the accuracy of the determination will be poor if the structural deterioration of the internally illuminated signboard 10 is determined based on this small number of vibrations. Therefore, by determining the structural deterioration of the internally illuminated signboard 10 by referring only to data in which the number of vibrations at a predetermined large acceleration is equal to or greater than a predetermined number, the accuracy of the determination of the structural deterioration of the internally illuminated signboard 10 can be improved even if the predetermined time for the vibration sensor 50 to measure vibrations is short.

[0049] <Variation 3> In the structure monitoring system 100 of the above embodiment, the vibration sensor 50 is provided on the mounting portion 12a of the frame 12 to measure vibrations and determine structural deterioration of the internally illuminated sign 10, such as the face plate 11, side plates 13, top plate 14, and bottom plate 15 coming loose. Without being limited to this, the structure monitoring system 100 may also provide the vibration sensor 50 in other locations, such as the side plates 13 and bottom plate 15. The structure monitoring system 100 may also determine structural deterioration in the event that other parts of the internally illuminated sign 10 come loose. Even in this case, the part that is coming loose will swing significantly, so structural deterioration can be determined in the same manner as in the above embodiment.

[0050] The configuration, operation, and effects of each embodiment of the present invention will be described below.

[0051] The structure monitoring system 100, which monitors an internally illuminated sign 10 as a structure installed outdoors, includes a vibration sensor 50 as a vibration measurement unit that measures the vibration of the internally illuminated sign 10 from the acceleration for a predetermined period of time, and a judgment unit 73 that judges structural deterioration of the internally illuminated sign 10 based on the measurement results of the vibration sensor 50. The judgment unit 73 judges structural deterioration of the internally illuminated sign 10 from the correlation between multiple judgment accelerations set in the measurement results and the number of vibrations, which is the number of times the acceleration of the internally illuminated sign 10 becomes equal to or greater than the judgment acceleration within a predetermined period of time.

[0052] In this configuration, the vibration sensor 50 only transmits the detection value, and the determination unit 73 can determine structural deterioration of the internally illuminated sign 10 with simple calculations and less processing without performing FFT analysis or the like. Also, compared to when FFT analysis or the like is performed, structural deterioration of the internally illuminated sign 10 can be determined with less data, so the amount of data communication by the vibration sensor 50 is small. Therefore, the power consumption of the structure monitoring system 100 can be reduced.

[0053] Furthermore, in the structure monitoring system 100, the determining unit 73 determines the structural deterioration of the internally illuminated signboard 10 based on the slope between two points on a log-log graph of acceleration and vibration frequency in the measurement results.

[0054] Furthermore, in the structure monitoring system 100, the judgment acceleration has a first judgment acceleration A and a second judgment acceleration B that is greater than the first judgment acceleration A, the vibration count has a first vibration count Na corresponding to the first judgment acceleration A and a second vibration count Nb corresponding to the second judgment acceleration B, and the judgment unit 73 judges the structural deterioration of the internally illuminated signboard 10 based on a first deterioration judgment value J1 obtained by dividing the second vibration count Nb by the first vibration count Na in the measurement results.

[0055] In these configurations, structural deterioration of the internally illuminated signboard 10 can be determined with simple calculations and minimal processing without performing FFT analysis or the like.

[0056] Furthermore, in the structure monitoring system 100, the judgment acceleration has a third judgment acceleration C which is smaller than the first judgment acceleration A and the second judgment acceleration B, and a fourth judgment acceleration D which is greater than the third judgment acceleration C and smaller than the first judgment acceleration A, the vibration count has a third vibration count Nc which corresponds to the third judgment acceleration C, and a fourth vibration count Nd which corresponds to the fourth judgment acceleration D, and the judgment unit 73 judges the structural deterioration of the internally illuminated signboard 10 based on the magnitude of the first deterioration judgment value J1 relative to the second deterioration judgment value J2 obtained by dividing the fourth vibration count Nd by the third vibration count Nc in the measurement results.

[0057] In this configuration, structural deterioration of the internally illuminated signboard 10 can be determined with a small amount of data communication and a small amount of processing.

[0058] In addition, in the structure monitoring system 100, the vibration sensor 50 measures the acceleration of the internally illuminated sign 10 multiple times for a predetermined period of time, and the judgment unit 73 judges the structural deterioration of the internally illuminated sign 10 based on the moving average value or moving median value of the first deterioration judgment value J1 calculated respectively from the multiple measurement results of the vibration sensor 50.

[0059] This configuration reduces the influence of factors such as wind speed, which varies from measurement to measurement, and allows for more accurate determination of structural deterioration of the internally illuminated signboard 10.

[0060] Furthermore, in the structure monitoring system 100, when the first vibration count Na and the second vibration count Nb are 0, the determination unit 73 does not use the corresponding first deterioration determination value J1 in calculating the moving average value or the moving median value.

[0061] With this configuration, the accuracy of determining the structural deterioration of the internally illuminated signboard 10 can be improved.

[0062] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments. [Explanation of symbols]

[0063] 10...interiorly illuminated signboard (structure), 50...vibration sensor (vibration measurement unit), 73...judgment unit, 100...structure monitoring system, A...acceleration (first judged acceleration), B...acceleration (second judged acceleration), C...acceleration (third judged acceleration), D...acceleration (fourth judged acceleration), J1...first deterioration judgement value, J2...second deterioration judgement value, Na...vibration count (first vibration count), Nb...vibration count (second vibration count), Nc...vibration count (third vibration count), Nd...vibration count (fourth vibration count)

Claims

1. A structure monitoring system for monitoring a structure provided outdoors, comprising: a vibration measuring unit that measures the vibration of the structure for a predetermined period of time based on the acceleration; a determination unit that determines structural deterioration of the structure based on the measurement results of the vibration measurement unit, A structure monitoring system characterized in that the judgment unit judges structural deterioration of the structure based on the correlation between multiple judgment accelerations set in the measurement results and the number of vibrations, which is the number of times the acceleration of the structure became equal to or greater than the judgment acceleration within the specified time.

2. 2. A structure monitoring system according to claim 1, A structure monitoring system characterized in that the determination unit determines structural deterioration of the structure based on the slope between two points on a double logarithmic graph of the acceleration and the vibration frequency in the measurement results.

3. 3. A structure monitoring system according to claim 2, The determined acceleration includes a first determined acceleration and a second determined acceleration that is greater than the first determined acceleration, the vibration frequency includes a first vibration frequency corresponding to the first determined acceleration and a second vibration frequency corresponding to the second determined acceleration, A structural monitoring system characterized in that the judgment unit judges structural deterioration of the structure based on a first deterioration judgment value obtained by dividing the second vibration count by the first vibration count in the measurement results.

4. 4. A structure monitoring system according to claim 3, the determined acceleration includes a third determined acceleration which is smaller than the first determined acceleration and the second determined acceleration, and a fourth determined acceleration which is larger than the third determined acceleration and smaller than the first determined acceleration, the vibration frequency includes a third vibration frequency corresponding to the third determined acceleration and a fourth vibration frequency corresponding to the fourth determined acceleration, A structure monitoring system characterized in that the judgment unit judges structural deterioration of the structure based on the magnitude of the first deterioration judgment value relative to a second deterioration judgment value obtained by dividing the fourth vibration count by the third vibration count in the measurement results.

5. 4. A structure monitoring system according to claim 3, The vibration measurement unit measures the acceleration of the structure a plurality of times for the predetermined period of time, A structural monitoring system characterized in that the judgment unit judges structural deterioration of the structure based on a moving average or moving median of the first deterioration judgment value calculated respectively from multiple measurement results of the vibration measurement unit.

6. 6. A structure monitoring system according to claim 5, A structure monitoring system characterized in that when the first vibration count and the second vibration count are 0, the judgment unit does not use the corresponding first deterioration judgment value in calculating a moving average value or a moving median value.

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