JP6761683B2 - Tilt monitoring system and method for columnar structures - Google Patents

Description

The present invention relates to tilt monitoring systems and methods applied to structures such as utility poles, bridges, houses, buildings, etc., where tilting may occur over time.

For example, utility poles have traditionally been installed throughout the town, but they may be tilted due to the effects of natural phenomena such as earthquakes and human activities such as construction and maintenance of electric wires. If a slope occurs and progresses, it may lead to a collapse accident. Regular slope inspection work is important to prevent collapse.

Patent Document 1 discloses a method of measuring an inclination angle using an inclination sensor including an accelerometer. Further, Patent Document 2 discloses an inclination abnormality detection device for a utility pole, in which an identification control communication unit is added to the inclination detection unit, each of the identification control communication units is fixedly arranged on the utility pole, and reported to a central control device by communication.

Japanese Unexamined Patent Publication No. 2006-133230 Japanese Unexamined Patent Publication No. 2004-147374

In order to prevent the collapse of utility poles, it is important to detect the occurrence of inclination at an early stage and deal with it. On the other hand, a business operator who manages utility poles generally manages a large number of utility poles scattered over a wide area for a long period of time. For example, a power company continuously manages millions of utility poles. The wireless tilt angle measuring device disclosed in Patent Document 2 realizes more efficient inspection, but it is still necessary for the worker to go to the site of the utility pole to collect data, and the inspection work is carried out. Requires a great deal of labor and cost.

Therefore, an object of the present invention is to efficiently and accurately manage the inclination angles of a large number of structures scattered over a wide area, for example, utility poles, and to detect the occurrence of inclination at an early stage.

One aspect of the present invention that solves the above problems is a tilt monitoring system including a sensor node and a server. In this system, the sensor node includes a sensor that measures the inclination of the object to be measured, a processing unit that processes the measurement data measured by the sensor, and a recording unit that records the processing data processed by the processing unit. , A transmission unit for transmitting the processing data recorded in the recording unit is provided. In addition, the server determines the tilt angle of the object to be measured based on the receiving unit that receives the processing data transmitted from the sensor node, the storage unit that stores the processing data received by the receiving unit, and the processing data stored in the storage unit. It includes a tilt angle calculation unit for calculation, a determination unit for determining the presence or absence of tilt based on the tilt angle calculated by the tilt angle calculation unit, and a notification unit for notifying the occurrence of tilt when the determination unit determines that there is tilt.

Another aspect of the present invention that solves the above problems is the first step of measuring the inclination of the object to be measured and obtaining the measurement data, averaging the plurality of measurement data to obtain the processed data. The second step to generate, the third step to calculate the tilt angle of the object to be measured based on the processing data, the fourth step to compare the calculated tilt angle with the threshold value, and the tilt occurrence when the tilt angle exceeds the threshold value. This is a tilt monitoring method including a fifth step of notifying.

According to the present invention, it is possible to efficiently and accurately manage the inclination angles of a large number of structures scattered over a wide area, for example, utility poles, and detect the occurrence of inclination at an early stage.

It is a block diagram which shows the structure of the inclination monitoring system in an Example. It is a block diagram which shows the example of the block diagram of the block diagram of the sensor node. It is a graph which shows the example of the fluctuation of the measurement data and the averaged data. It is a table figure which shows the example of the numerical value of the measurement data and the averaging data. It is a table figure which shows the configuration example of the transmission data of a sensor node. It is a block diagram which shows the example of the gateway configuration. It is a block diagram which shows an example of a server configuration. It is a top view which shows the example of the screen display of a server. It is a flowchart which shows a series of measurement operations of an inclination monitoring system. It is a graph which shows the fluctuation of the acceleration applied to the utility pole equipment when resonance occurs, and the example of the measurement data. It is a conceptual diagram which shows the example of the fluctuation of the acceleration applied to the utility pole equipment when the train vibration occurs. It is a graph which shows the fluctuation of the acceleration applied to the utility pole equipment and the example of the measurement data when a big vibration occurs. It is a block diagram which shows the example of the block diagram of the block diagram of the sensor node in Example 4. It is a flowchart which shows the operation when the threshold value determination process of Example 4 is performed. It is a top view which shows the example of the screen display of the server in Example 5. FIG.

Examples of the tilt monitoring system to which the present invention is applied and the processing method thereof will be described in detail with reference to the following drawings. In the following description, in the description of the drawings, the same parts may be designated by the same reference numerals and the description thereof may be omitted.

In the embodiment, when there are a plurality of components that can be regarded as equivalent, the same code may be subscripted to distinguish them. However, if it is not necessary to distinguish between them, the subscripts may be omitted.

The position, size, shape, range, etc. of each configuration shown in the drawings and the like may not represent the actual position, size, shape, range, etc. in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings and the like.

The present inventors have focused on the fact that the inclination angle of the utility pole is not constant because the utility pole frequently shakes due to the influence of the surrounding environment when continuously monitoring the inclination angle of the utility pole. Specific examples of shaking due to the influence of the surrounding environment are shaking caused by the natural environment such as rain and wind, and shaking caused by ground vibration generated when a train or the like passes in the vicinity. Then, the inventors have stated that the inclination angle of the utility pole is a mixture of a component indicating the degree of inclination of the utility pole itself, which is a structure, and a temporary fluctuation component generated by a phenomenon caused by the surrounding environment. I found a new one. In particular, although it is necessary to detect a minute inclination angle of about 0.5 degrees for early detection of the inclination, the shaking due to the influence of the surrounding environment is also the same, and it is difficult to distinguish the inclination.

Based on this new finding, in order to accurately calculate the tilt angle of the electric pole itself, the basic configuration of the tilt monitoring system according to the embodiment described below is an acceleration sensor that measures the tilt of the object to be measured. A sensor node including a processing unit that processes the measurement data acquired by measurement, a recording unit that records the processed processing data, and a radio unit that transmits the recorded processing data, and transmission from the sensor node. The communication unit that receives the processed data via the gateway, the storage unit that stores the received processing data, the tilt angle calculation unit that calculates the tilt angle of the measurement object based on the stored processing data, and the calculated tilt angle. It has a determination unit for determining the presence or absence of inclination based on the above, and a server including a notification unit for notifying the occurrence of abnormal inclination when it is determined that there is an inclination.

An example of processing on measurement data for reducing the influence of noise caused by the influence of the surrounding environment is averaging processing.

In addition, in order to remove noise caused by the influence of the surrounding environment as much as possible, the characteristics and causes of noise in the surrounding environment are examined in advance, and processing corresponding to the characteristics and causes of the noise is performed. As a result, the noise component contained in the acquired measurement data is removed.

<1. Overall system configuration>
FIG. 1 is an installation example of the inclination monitoring system in this embodiment. First, in FIG. 1, the area to be measured by the tilt monitoring system is divided into sites 1a, 1b, and 1c for each base. There are a plurality of utility pole equipment 5 to be measured at each site 1, and a sensor node 2 is installed for each utility pole equipment 5.

The sensor node 2 has a function of measuring the acceleration applied to the utility pole equipment 5. Further, the sensor node 2 has a function for transmitting measurement data to the gateway 3. Since the sensor node 2 is installed in a large number of utility pole facilities 5, it is desirable to adopt an inexpensive configuration.

Further, a gateway 3 having a relay function is installed at each of the sites 1a, 1b, and 1c. The gateway 3 receives the measurement data transmitted from the sensor node 2 in the same site. When the site 1 is a wide area (for example, 1000 m square or more) and the radio wave of the short-range radio (for example, the communicable distance is 100 m) does not reach, a plurality of gateways 3 may be installed. Further, the gateway 3 may be installed in a fixed storage facility or the like, or may be carried by an inspector who walks for inspection or operational reasons.

The gateway 3 transmits information such as measurement data received from the sensor node 2 to the server 4 via the wide area network 6. Examples of the transmission method from the gateway 3 to the wide area network 6 include a long-distance radio (for example, a communicable distance of 1 km or more). For this purpose, a telecommunications receiving facility (not shown) is connected to the wide area network 6.

The server 4 has a function of accumulating information received via the wide area network 6 and monitoring the inclination state of the utility pole equipment 5. The server 4 calculates the tilt angle from the aggregated acceleration measurement data and monitors the tilt status of each utility pole facility 5. When the inclination angle exceeds a preset threshold value, the server 4 notifies the administrator 7 by a notification means such as an e-mail. As the threshold value, for example, the notification is performed with an inclination of 5 degrees, and in this case, the resolution of the inclination angle measurement may be, for example, about 0.5 degrees.

Further, since the sensor node 2 is installed on a pole on the utility pole facility 5, labor is required for laying wiring for power supply and battery replacement work. In order to realize long-term operation, it is desirable that the sensor node 2 is provided with a power supply mechanism composed of a solar panel or the like and operates with the electric power. Further, it is desirable that the sensor node 2 is designed to reduce power consumption. Due to such restrictions, it is desirable for the operation of this system to keep the amount of information transmitted by the sensor node 2 small.

<2. Sensor node>
FIG. 2 shows a configuration example of the sensor node 2 in this embodiment. The sensor node 2 includes a control unit 20, an acceleration sensor 21, a recording unit 22, an averaging processing unit 23, a short-range radio unit 24, an antenna 25, a clock unit 26, and a power supply unit 27. Here, the control unit 20 and the averaging processing unit 23 are realized as software. The software will be implemented on the recording unit 22. The functions of each part will be described below.

The control unit 20 issues data transfer and operation instructions to the acceleration sensor 21, the recording unit 22, the averaging processing unit 23, the short-range radio unit 24, and the clock unit 26, and controls the overall operation of the sensor node 2. .. A series of operations of the control unit 20 will be described later.

The acceleration sensor 21 has a function of measuring the value of the acceleration applied to the utility pole equipment 5. The acceleration sensor 21 can measure acceleration in a plurality of directions such as a north-south direction and an east-west direction. For example, Patent Document 1 and the like disclose a configuration for measuring acceleration. Further, an acceleration sensor using MEMS (Micro Electro Mechanical Systems) is known. The acceleration sensor 21 records the measured acceleration data (hereinafter referred to as measurement data) in the recording unit 22. Further, the acceleration sensor 21 has a function of acquiring time information from the clock unit 26.

The recording unit 22 is for recording measurement data and averaging data described later. Various storage devices can be used for the recording unit 22. For example, a non-volatile semiconductor memory such as a flash memory can be used.

The averaging processing unit 23 performs averaging processing for calculating an average value from acceleration data. Here, the effect of the averaging process will be described. The inclination angle of the utility pole is a mixture of a component indicating the degree of inclination of the utility pole itself (hereinafter referred to as an inclination component) and a temporary fluctuation component generated by a phenomenon caused by the surrounding environment (hereinafter referred to as a fluctuation component). ing. For example, a fluctuation component of about 0.5 degrees is generated by pulling a utility pole due to vibration of an overhead wire due to a strong wind. In response to this, the acceleration measured on the utility pole also includes the acceleration of the tilt component and the acceleration of the fluctuation component.

FIG. 3 shows an example of acceleration fluctuation when a tilt angle fluctuation component is generated. The horizontal axis is time and the vertical axis is acceleration. As shown in FIG. 3, the measurement data indicated by the black circle has a form in which the acceleration fluctuation component is superimposed on the acceleration gradient component.

FIG. 4 shows an example of measured values. When vibration occurs, measurement data (for example, 0.98) that greatly deviates from the tilt component is generated. Here, the value obtained by subjecting the measurement data to the averaging process (hereinafter referred to as the averaging data) can be conveniently defined by the following equation 1.
ai + (1 / N) Σbi ・ ・ ・ (Equation 1)

ai is the gradient component of acceleration, bi is the fluctuation component of acceleration, and N is the number of measurement data to be averaged. The larger the number of data to be averaged, the more the variable component can be reduced. When the vibration caused by the running of the train is the target of the fluctuation component, the influence can be sufficiently reduced by generating the averaging data from the measurement data for about several minutes. For example, if the measurement data for about 8 minutes is targeted for averaging, the fluctuation component of the acceleration due to the vibration can be sufficiently reduced while the 15-car train passes in the vicinity. Specifically, it is obtained by (train length (m) ÷ running speed V (m / s)) × safety factor 30 or the like. 25m x 15 ÷ 24 x 30 times = about 8 minutes.

The averaging data obtained by averaging the measurement data is shown by white circles in FIG. As a result of the averaging process, it is possible to obtain a highly accurate tilt angle with less influence of vibration as compared with the case where the tilt angle is calculated from the measurement data of the acceleration sensor 21 as in the conventional case.

Further, by transmitting the averaging data (white circles in FIG. 3) by the averaging process, it is possible to obtain the effect of compressing the communication amount as compared with transmitting the measurement data (black circles in FIG. 3) as it is. This is effective in reducing the power consumption of the sensor node 2. The averaging processing unit 23 records the calculated acceleration averaging data in the recording unit 22.

As described above, the control unit 20 and the averaging processing unit 23 in FIG. 2 are realized as software. That is, the functions of the control unit 20 and the averaging processing unit 23 cooperate with other hardware in the defined processing by executing the program stored in the recording unit 22 by a processing device (not shown) alone. Will be realized. A program executed by a computer or the like, its function, or a means for realizing the function may be referred to as a "function", a "means", a "part", a "unit", a "module", or the like.

The functions equivalent to the functions configured by software can also be realized by hardware such as FPGA (Field Programmable Gate Array) and ASIC (Application Specific Integrated Circuit).

The short-range radio unit 24 has a function of transmitting averaging data and time information provided by the clock unit 26 to the gateway 3 via the antenna 25. The short-range radio unit 24 repeatedly executes the transmission process in synchronization with the measurement process of the predetermined acceleration sensor 21.

At this time, the short-range radio unit 24 holds an identification ID (MAC address, etc.) uniquely assigned to each sensor node 2. Therefore, the received gateway 3 can determine the source sensor node 2.

FIG. 5 shows a configuration example of transmission data of the short-range wireless unit 24. The transmission data of the short-range radio unit 24 includes the sensor node identification ID, the averaging data corresponding to each axis such as the xyz of the acceleration sensor, and the measurement time. Here, if the size of the transmission data can be increased, the operation information of the sensor node 2 and the like may be transmitted at the same time. For example, if the supply voltage value of the power supply unit 27 and the past measurement data history are simultaneously transmitted, it is useful for the operation management of the sensor node 2. The antenna 25 has a function of transmitting short-range radio waves. Further, a receiving function may be provided.

The clock unit 26 has a function of providing the current time. The current time may be measured by the clock unit 26 by itself, or may be acquired based on a signal from the outside.

The power supply unit 27 has a function of supplying electric power to each unit of the sensor node 2. The power supply unit 27 may be composed of a solar panel or the like to generate electric power from natural energy, or may be composed of a storage battery such as a lithium ion battery.

<3. Gateway ＞
FIG. 6 shows a configuration example of the gateway 3 in this embodiment. The gateway 3 includes a control unit 30, a short-range wireless unit 31, a short-range wireless antenna 32, a long-range wireless unit 33, a long-range wireless antenna 34, and a power supply unit 35. The functions of each part will be described below.

The control unit 30 has a function of controlling the short-range radio unit 31 and the long-distance radio unit 33. A series of operations of the control unit 30 will be described later. The control unit 30 can be configured by software or hardware like the control unit 20 of the sensor node 2.

The short-range radio unit 31 has a function of communicating with the sensor node 2 through the short-range radio antenna 32.

The short-range radio antenna 32 has a function of receiving short-range radio waves. Further, a transmission function may be provided.

The telecommunications unit 33 has a function of communicating with the server 4 through the telecommunications antenna 34. The gateway 3 and the server 4 are installed at different locations. Therefore, the communication is performed via the wide area network 6 by wireless communication between the gateway 3 and the wide area network 6, and by wired communication between the wide area network 6 and the server 4. The timing at which the long-distance wireless unit 33 operates may be synchronized with the averaged data reception of the short-range wireless unit 31, but a storage area is provided in the long-distance wireless unit 33 or the like and temporarily stored in the buffer, and then later. You may send it with.

The telecommunications antenna 34 has a function of transmitting telecommunications radio waves. Further, it may be provided with a receiving function.

The power supply unit 35 has a function of supplying electric power to each unit of the gateway 3. The power supply unit 35 may be configured by a storage battery such as a lithium ion battery, or may be configured by an AC adapter or the like at a site where electric power can be obtained from the outside.

<4. Server ＞
FIG. 7 shows a configuration example of the server 4 in this embodiment. The server 4 includes a control unit 40, a communication unit 41, a storage unit 42, an inclination angle calculation unit 43, an inclination threshold value determination unit 44, a notification unit 45, and a screen display unit 46. The functions of each part will be described below.

The control unit 40 has a function of controlling a communication unit 41, a storage unit 42, an inclination angle calculation unit 43, an inclination threshold value determination unit 44, a notification unit 45, and a screen display unit 46. A series of operations of the control unit 40 will be described later. The control unit 40 can be configured by software or hardware like the control unit 20 of the sensor node 2.

The communication unit 41 has a function of communicating with the gateway 3. The gateway 3 and the server 4 are installed at different locations. Therefore, the communication goes through the wide area network 6. Therefore, the communication unit 41 is provided with an interface for connecting to a wide area network 6 such as the Internet.

The storage unit 42 stores the averaging data transmitted by the sensor node 2. The averaging data is organized and accumulated for each identification information of the sensor node 2. The storage unit 42 can use a storage device such as a semiconductor memory or a magnetic disk.

The inclination angle calculation unit 43 has a function of calculating the inclination direction in which the utility pole equipment 5 is most inclined and the inclination angle thereof from the averaging data accumulated in the storage unit 42. The method of calculating the tilt direction and the tilt angle from the acceleration can be calculated by the following formula, for example, when the acceleration sensor can acquire the accelerations Ax and Ay of the two axes of the x-axis and the y-axis. The symbol "^ 2" indicates square. g is the gravitational acceleration.
Tilt direction: Arctan (Ay / Ax)
Tilt angle: Arcsin (√ ((Ax ^ 2) ＋ (Ay ^ 2)) / g)
The tilt angle calculation unit 43 stores the calculated tilt direction and tilt angle in the storage unit 42.

The inclination threshold value determination unit 44 has a function of comparing the inclination angle with a preset threshold value and determining the magnitude. When the inclination angle exceeds the threshold value, the inclination threshold value determination unit 44 notifies the notification unit 45 of the occurrence of an abnormal inclination.

The notification unit 45 has a function of notifying the occurrence of tilt to the terminals used by one or more administrator 7s registered in advance. As the notification means, the e-mail may be notified to the e-mail address of the administrator's terminal, or may be displayed on the liquid crystal display of the terminal. It is desirable that the information to be notified includes at least the identification information of the utility pole equipment 5 and the information of the inclination angle.

The inclination angle calculation unit 43, the inclination threshold value determination unit 44, and the notification unit 45 can be configured by software or hardware in the same manner as the control unit 40.

The screen display unit 46 has a function of displaying the notification of the notification unit 45. In addition, it has a function of displaying the status of the utility pole equipment 5 stored in the storage unit 42 in response to the request of the administrator.

FIG. 8 shows an example of the display of the screen display unit 46. The screen display unit 46 displays the sensor node identification ID, the measurement time, the tilt direction, the tilt angle, and the abnormality determination result. The displayed abnormality judgment result reflects the actual inclination angle by reducing the influence of the fluctuation component of the acceleration. Therefore, the inclination angle of the utility pole can be grasped efficiently and accurately.

<5. Processing flow>
With reference to FIG. 9, in this embodiment, a series of operations from measurement of acceleration to notification to the administrator 7 will be described using a flowchart.

The control unit 20 of the sensor node 2 reads the time information from the clock unit 26 and determines whether or not it is the measurement time (501). Here, when the control unit 20 determines that the measurement time is a predetermined time (Yes at 501), the acceleration sensor 21 measures the acceleration applied to the utility pole equipment 5 (502). Since the acceleration sensor 21 can measure acceleration in a plurality of directions, it measures each direction and records the measurement data in the recording unit 22.

When the number of measurement data reaches the predetermined number of measurement times N (Yes at 503), the control unit 20 sends the measurement data to the averaging processing unit 23. The averaging processing unit 23 performs averaging processing on the measurement data for each measurement direction (504). At the same time, the control unit 20 acquires the time information from the clock unit 26 and records it in the recording unit 22 together with the averaging data (505). On the other hand, when the number of measurement data is less than the predetermined number of measurement times N (No at 503), the control unit 20 finishes the process and waits for the next measurement time.

On the other hand, when it is not the measurement time in step 501 (No in 501), the control unit 20 reads the time information from the clock unit 26 and determines whether or not it is the transmission time (506). Here, if it is not the transmission time (No in 506), the control unit 20 finishes the process and waits for the next measurement time.

When it is the transmission time (Yes at 506), the control unit 20 extracts the latest averaging data from the recording unit 22 (507) and instructs the short-range radio unit 24 to transmit (507). The measurement time interval and transmission time interval can be set arbitrarily. For example, if it is set so that measurement can be performed at least N times between the transmission times, new averaging data can be transmitted each time, but the present invention is not limited to this.

The short-range radio unit 24 transmits the averaging data and the time information to the gateway 3 by short-range radio (508).

The short-range radio unit 31 of the gateway 3 receives the data transmitted by the sensor node 2. The control unit 30 passes the received data from the short-range radio unit 31 to the long-range radio unit 33. Then, the telecommunications unit 33 transmits to the server 4 (510).

The communication unit 41 of the server 4 receives the data transmitted by the gateway 3 and stores it in the storage unit 42 (511). The control unit 40 passes the averaging data stored in the storage unit 42 to the inclination angle calculation unit 43. The timing at which the averaging data is passed to the inclination angle calculation unit 43 can be arbitrarily determined. For example, the latest averaging data may be passed to the tilt angle calculation unit 43 each time the data transmitted by the gateway 3 is received, but the present invention is not limited to this.

The inclination angle calculation unit 43 calculates the most inclined direction of the utility pole equipment 5 and the inclination angle thereof from the averaging data, and records it in the storage unit 42 (512). If the calculated tilt angle, for example, the maximum tilt angle is within a preset threshold value (No in 513), the tilt threshold value determination unit 44 ends the process without raising an alarm for the occurrence of an abnormal tilt.

When the calculated tilt angle, for example, the maximum tilt angle exceeds a preset threshold value (Yes at 513), the tilt threshold determination unit 44 sends an alarm for the occurrence of an abnormal tilt to the notification unit 45.

When the notification unit 45 receives an alarm from the inclination threshold value determination unit 44, the notification unit 45 notifies, for example, the administrator 7 that the inclination has occurred (514).

As described above, according to the present embodiment, the fluctuation component can be reduced and the inclination component of the utility pole itself can be extracted by performing the averaging process on the acceleration value measured by the sensor node 2. .. Then, since the server 4 monitors the presence or absence of an abnormality based on the degree of inclination of the utility pole itself by using the averaging data in which the fluctuation component is reduced, the mere inclination of the utility pole whose fluctuation component is not reduced as in the conventional case. Compared with the monitoring of the presence or absence of abnormalities based on the angle, highly accurate monitoring becomes possible.

The fluctuation component of the inclination angle causes an erroneous judgment when constructing a system for detecting a sign of collapse of a utility pole. For example, when an abnormal alert is given based on the measured tilt angle as in the conventional case, there is a concern that the fluctuation component due to vibration is erroneously recognized as the occurrence of tilt, and false alarm alerts occur frequently. On the other hand, in the system to which this embodiment is applied, since it is determined that there is no abnormality in the inclination angle of the utility pole based on the averaging data with the fluctuation component reduced, there are problems such as frequent false alarm alerts due to the fluctuation component. Can be solved.

Further, the averaging process reduces the amount of information of the measurement data and enables the sensor node 2 to reduce the power consumption. Further, by adopting a data collection method that combines short-range radio and long-range radio by the gateway 3, acceleration applied to a large number of utility poles scattered over a wide area is efficiently collected. According to this embodiment, it is possible to construct a tilt monitoring system that accurately detects the occurrence of a tilt and raises an alert, and makes it possible to prevent a collapse accident.

In the configuration of Example 1 above, the influence of variable components was reduced by the averaging process. However, the effect of the averaging process depends on the variance of the measured data. Therefore, depending on the value of the measurement data and the number of data, it is possible that the variable component remains in the averaged data. For example, when too large measurement data is recorded, the effect cannot be sufficiently reduced only by the averaging process. Further, when it is desired to measure the inclination angle with high frequency, the data to be averaged is reduced and the variable component tends to remain. Therefore, in addition to the averaging process, a method of reducing the fluctuation component at the acquisition stage of the measurement data and improving the tilt monitoring accuracy will be described below as another embodiment.

Resonance may occur if there are other structures around the object to be measured. For example, in a utility pole installed near the viaduct, when the resonance frequencies of the viaduct and the utility pole match, vibration of a large amplitude occurs due to the resonance phenomenon. The resonance frequency of the utility pole is about 1 to 10 Hz. Therefore, the present inventors paid attention to the relationship between the natural frequency of the utility pole and the measurement cycle of the inclination angle. Then, the inventors have newly found that Example 1 is greatly affected by the resonance phenomenon depending on the value of the measurement cycle. Based on this new finding, a means for improving the tilt monitoring accuracy will be described as Example 2. The effect of the resonance phenomenon will be described below.

FIG. 10 is a diagram showing an example of acceleration and measurement data when the utility pole equipment 5 resonates in the first embodiment. The horizontal axis shows time and the vertical axis shows acceleration. When the utility pole equipment 5 resonates, the acceleration becomes a sinusoidal curve such as 602. At this time, if the measurement cycle of the sensor node 2 is close to the resonance frequency, the sensor node 2 may acquire only an acceleration larger than the inclination component originally desired to be measured (for example, in the vicinity of the measured values H1 and H2). .. In such a state, even if the measurement data is averaged, the variable component cannot be reduced.

Therefore, by adjusting the measurement cycle of the acceleration sensor 21 of the sensor node 2, the influence of the fluctuating component is reduced. Specifically, the measurement cycle Ts of the acceleration sensor 21 is set so as to satisfy the following equation.
Ts ≤ 1 / (2 ・ Fp) ・ ・ ・ ・ (Equation 2)
Fs ≧ 2 Fp
Here, Ts represents the measurement cycle of the acceleration sensor 21, Fs represents the sampling rate of the acceleration sensor 21, and Fp represents the resonance frequency of the utility pole equipment 5. By satisfying the above conditions, the measurement data includes not only a value larger than the inclination component but also a value smaller than the inclination component.

For example, in the example of FIG. 10, the measurement period (Ts) = half of the vibration period (1 / (2 · Fp)). In this example, since the measurement data includes both values H1 and H2 that are larger than the slope component and values L1 and L2 that are smaller than the slope component, the larger and smaller values cancel each other out in the averaging process, and the variable component is eliminated. It can be reduced. Even when the phase of the measurement cycle is deviated, the effect of canceling the large value and the small value of the measurement data is the same. Here, as shown in FIG. 3, sufficient accuracy can be obtained by averaging with the number of past measurement data N = 5. How many data N should be used for averaging depends on the environment of the target utility pole equipment, etc., so it may be decided by examining past data.

Further, when the measurement cycle is further shortened, the canceling effect between adjacent measurement data becomes smaller, but only the acceleration larger (or smaller) than the inclination component originally desired to be measured is not acquired. In addition, as the sampling rate increases, the effect of leveling by the averaging process becomes remarkable.

As a result, the averaging process can reduce the fluctuation component due to the resonance phenomenon, and a measured value close to the acceleration 601 when there is no resonance can be obtained.

In this embodiment, the sensor node 2 holds the measurement cycle setting in the recording unit 22. If it is known in advance that the utility pole equipment 5 to be monitored resonates, a measurement cycle is set in the recording unit 22. The sensor node 2 may be provided with a mechanism capable of changing the setting in case resonance is found after the installation of the sensor node 2.

As described above, by determining the measurement cycle of the sensor node 2 based on the resonance frequency of the utility pole equipment 5, the influence of resonance can be reduced and the tilt monitoring accuracy can be improved.

Utility poles installed near railroad tracks are subject to large vibrations that occur when trains run. The present inventors have focused on the fact that the vibration generated when a train runs has a peak in a specific frequency band. Then, it was newly found that the frequency can be specified in advance. Based on this new finding, a means for improving the tilt monitoring accuracy will be described as Example 3. The vibration generated by the running of the train will be described below.

FIG. 11 is a diagram showing an example of acceleration fluctuation due to the running of the train 110. As shown in FIG. 11A, the main cause of vibration caused by the train 110 is the impact of the wheels and the track generated when the train 110 passes through the seam 111 of the track. Therefore, the impact is repeatedly generated by the number of wheels, and the time interval of the impact depends on the physical interval of the wheels. Therefore, as shown in FIG. 11B, when time is shown on the horizontal axis and acceleration is shown on the vertical axis, vibration peaks appear at predetermined intervals in the acceleration 701 affected by train running. ..

At this time, since vibrations are superimposed, the peak frequency F is determined by the wheel spacing and the train speed, and is expressed by the following equation.
F ＝ V / L
L is the distance between the wheels, and V is the traveling speed of the train 110. From the above equation, the frequency band 703 at which the vibration peaks can be grasped.

FIG. 11C shows the frequency on the horizontal axis, the acceleration on the vertical axis, and the acceleration 702 affected by the train running. By removing the frequency band 703 of the frequency F = V / L or higher, which is the peak of vibration, the influence of train running can be reduced.

Based on the above findings, the configuration of the tilt monitoring system in this embodiment will be described. It is assumed that the acceleration sensor 21 of the sensor node 2 has an LPF (Low Pass Filter) processing function inside. Generally, the acceleration sensor device is equipped with an LPF processing function for the purpose of suppressing the influence of electrical noise and camera shake when held in the hand.

The LPF treatment blocks high frequency components having a certain frequency or higher. The details of the LPF processing of the acceleration sensor device are known depending on the product and the like. The acceleration sensor 21 executes LPF processing at the time of acquisition of measurement data, and removes the frequency component of the train vibration obtained by the above equation.

The sensor node 2 shall hold the setting of the cutoff frequency for LPF processing in the recording unit 22. Further, the sensor node 2 may be provided with a mechanism capable of changing the setting.

As described above, the acceleration sensor 21 is provided with LPF processing, and by setting the cutoff frequency of LPF processing to a frequency peculiar to the vibration factor, the influence of vibration of train running is reduced and the tilt monitoring accuracy is improved. be able to.

By using the LPF treatment of Example 3 in combination with the averaging treatment of Example 1, the effect of reducing the fluctuation component of acceleration by the averaging treatment can be increased. Further, in a situation where the cause of the fluctuation component of the acceleration is limited to the high frequency component having a predetermined frequency or higher, a certain effect can be obtained without combining with the averaging process.

If the amplitude of the vibration received by the utility pole equipment 5 is too large, the effect may not be sufficiently reduced only by the averaging process. For example, when an object collides with the utility pole equipment 5, or when a bird or the like rides on the sensor node 2. Such vibration will be described below.

FIG. 12 is a diagram showing an example of acceleration when a large vibration is momentarily received in the first embodiment. The horizontal axis shows time and the vertical axis shows acceleration. The measured values 901 are obtained discretely. When a large vibration occurs, the sensor node 2 acquires a very large measurement data such as the measured value 901x. The data to be averaged by the sensor node 2 is the acceleration 902 that has received sudden vibration, which includes the influence of the measured value 901x, which is a variable component. When the number of data in the averaging process is small, the averaging data is greatly affected by the variable component. A method for reducing variable components will be described below as Example 4 of the present invention in response to such problems.

FIG. 13 shows a configuration example of the sensor node 2a in this embodiment. The sensor node 2a includes an acceleration threshold value determination unit 28 in addition to the configuration of the sensor node 2 of the first embodiment. The acceleration threshold value determination unit 28 has a function of reading the measurement data held by the recording unit 22 and comparing it with a predetermined threshold value 903 (FIG. 12). The acceleration threshold value determination unit 28 shall hold the setting of the threshold value 903 in the recording unit 22. Further, the sensor node 2 may be provided with a mechanism capable of changing the setting.

The flowchart of FIG. 14 shows the operation of the tilt monitoring system of this embodiment. Since the steps with the same reference numerals as those in FIG. 9 show the same operation, only steps 502 to 503 related to the acceleration threshold value determination unit 28 will be described here. In step 502, the acceleration sensor 21 stores the measurement data in the recording unit 22. Next, the acceleration threshold value determination unit 28 reads the measurement data from the recording unit 22 and compares the preset threshold value with the measurement data (502-2). When the measurement data is within the threshold value (Yes in 502-2), the acceleration threshold value determination unit 28 finishes the process and proceeds to step 503. When the measurement data exceeds the threshold value (No in 502-2), the acceleration threshold value determination unit 28 deletes the measurement data and returns to step 501.

As described above, the acceleration threshold value determination unit 28 excludes the measurement data when the measurement data exceeds the threshold value, thereby reducing the influence of large vibrations and improving the tilt monitoring accuracy. Can be done. As the threshold value, a fixed value may be used as shown in FIG. 12 to compare with the measurement data, or the difference between the immediately preceding measurement data and the latest measurement data is calculated, and the difference is compared with the threshold value to exceed the threshold value. If there is a difference between, the latest measurement data may be deleted.

By using the process of Example 4 in combination with the processes of Examples 1 to 3, the accuracy of acceleration measurement can be increased. For example, when combined with the averaging process of the first embodiment, when the measurement data exceeds the threshold value, the measurement data is excluded from the target of the averaging process, so that the tilt monitoring accuracy can be further improved. Moreover, a certain effect can be obtained even if it is used alone.

When construction is carried out near utility poles, the probability of tilting increases significantly. In particular, when a large number of utility poles are tilted all at once around the construction site, the repair work requires a great deal of labor. In such a case, it is desirable to predict the occurrence of abnormal inclination and perform repair at an early stage, instead of repairing after the occurrence of inclination. For such a problem, the prediction of the abnormal inclination will be described below as Example 5 of the present invention.

FIG. 15 is an example of the display of the screen display unit 46 of the server 4. The screen display unit 46 displays the sensor node identification ID, the measurement time, the tilt direction, the tilt angle, the tilt change rate, and the abnormality determination result. The inclination change rate represents a change in the inclination angle of the utility pole equipment 5.

The inclination angle calculation unit 43 calculates the inclination direction and the inclination angle of the utility pole equipment 5 from the averaging data, and also calculates the inclination change rate from the past accumulated data. The inclination change rate represents the speed of inclination of the utility pole over time. For example, the difference from the tilt angle at the same time 24 hours ago is calculated, and the rate of change in the tilt angle per day is calculated. The tilt angle calculation unit 43 records the tilt change rate in the storage unit 42 together with the tilt angle.

The inclination threshold value determination unit 44 determines a threshold value for the calculated inclination change rate based on the inclination change rate threshold value. When the inclination change rate exceeds the threshold value, the notification unit 45 notifies the administrator 7 that there is a high possibility that an abnormal inclination will occur.

As described above, according to the present embodiment, since the abnormal inclination is detected based on the rate of change of the inclination angle, the inclination can be monitored in consideration of the inclination speed of the utility pole. As a result, it is possible to predict an abnormal inclination that is within the threshold value as the inclination angle but may collapse, and to carry out the repair work at an early stage.

According to the embodiment of the present invention, since the temporary fluctuation component due to the surrounding environment is reduced with respect to the measured inclination angle of the utility pole, it is possible to accurately calculate the inclination degree of the utility pole itself. .. As a result, it is possible to efficiently and accurately manage the inclination angles of a large number of utility poles scattered over a wide area. Then, according to the embodiment of the present invention, it is possible to detect an abnormal state of inclination at an early stage and accurately notify an administrator or the like.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add / delete / replace the configurations of other examples with respect to a part of the configurations of each embodiment.

1 Site 2 Sensor node 3 Gateway 4 Server 5 Electric pole equipment 6 Wide area network 7 Administrator 21 Accelerometer 22 Recording unit 23 Average processing unit 24 Short-range radio unit 25 Antenna 26 Clock unit 27 Power supply unit 28 Acceleration threshold judgment unit 31 Short-distance Radio unit 32 Short-range radio antenna 33 Long-range radio unit 34 Long-range radio antenna 41 Communication unit 42 Storage unit 43 Tilt angle calculation unit 44 Tilt threshold determination unit 45 Notification unit 46 Screen display unit

Claims (7)

An inclination monitoring system for columnar structures equipped with sensor nodes and servers.
The sensor node
A sensor that measures the inclination of the object to be measured and
A processing unit that processes the measurement data measured by the sensor, and
A recording unit that records the processing data processed by the processing unit, and
A transmission unit for transmitting the processed data recorded in the recording unit is provided.
The server
A receiving unit that receives the processed data transmitted from the sensor node, and
A storage unit that stores the processing data received by the reception unit,
An inclination angle calculation unit that calculates the inclination angle of the measurement object based on the processing data accumulated in the storage unit,
A determination unit that determines the presence or absence of inclination based on the inclination angle calculated by the inclination angle calculation unit,
It is provided with a notification unit for notifying the occurrence of inclination when the determination unit determines that there is an inclination.
The processing unit
An averaging process is performed using the plurality of the measured data, and the averaging data is calculated as the processed data.
The transmitter
Send the averaging data and
The sensor is
When the measurement cycle of the sensor is Ts, the sampling rate of the sensor is Fs, and the resonance frequency of the measurement object is Fp.
Ts ≤ 1 / (2 ・ Fp)
Fs ≧ 2 Fp
Measure under the conditions of
Tilt monitoring system for columnar structures . An inclination monitoring system for columnar structures equipped with sensor nodes and servers.
The sensor node
A sensor that measures the inclination of the object to be measured and
A processing unit that processes the measurement data measured by the sensor, and
A recording unit that records the processing data processed by the processing unit, and
A transmission unit for transmitting the processed data recorded in the recording unit is provided.
The server
A receiving unit that receives the processed data transmitted from the sensor node, and
A storage unit that stores the processing data received by the reception unit,
An inclination angle calculation unit that calculates the inclination angle of the measurement object based on the processing data accumulated in the storage unit,
A determination unit that determines the presence or absence of inclination based on the inclination angle calculated by the inclination angle calculation unit,
It is provided with a notification unit for notifying the occurrence of inclination when the determination unit determines that there is an inclination.
The processing unit
An averaging process is performed using the plurality of the measured data, and the averaging data is calculated as the processed data.
The transmitter
Send the averaging data and
The sensor is
LPF processing is performed to block a frequency region equal to or higher than a predetermined value in the measurement data.
Tilt monitoring system for columnar structures . An inclination monitoring system for columnar structures equipped with sensor nodes and servers.
The sensor node
A sensor that measures the inclination of the object to be measured and
A processing unit that processes the measurement data measured by the sensor, and
A recording unit that records the processing data processed by the processing unit, and
A transmission unit for transmitting the processed data recorded in the recording unit is provided.
The server
A receiving unit that receives the processed data transmitted from the sensor node, and
A storage unit that stores the processing data received by the reception unit,
An inclination angle calculation unit that calculates the inclination angle of the measurement object based on the processing data accumulated in the storage unit,
A determination unit that determines the presence or absence of inclination based on the inclination angle calculated by the inclination angle calculation unit,
It is provided with a notification unit for notifying the occurrence of inclination when the determination unit determines that there is an inclination.
The processing unit
An averaging process is performed using the plurality of the measured data, and the averaging data is calculated as the processed data.
The transmitter
Send the averaging data and
The sensor node includes an acceleration threshold value determination unit.
The acceleration threshold value determination unit
The size of the measurement data is determined, and the measurement data of a predetermined size based on physical interference with the measurement object is excluded.
Tilt monitoring system for columnar structures . The tilt angle calculation unit
Calculate the slope change rate from the past accumulated data,
The inclination monitoring system for a columnar structure according to any one of claims 1 to 3. The first step of measuring the inclination of the object to be measured and obtaining the measurement data,
A second step of performing averaging processing on a plurality of the measurement data to generate processed data,
The third step of calculating the inclination angle of the measurement object based on the processing data,
Fourth step of comparing the calculated tilt angle with the threshold value,
Fifth step of notifying the occurrence of inclination when the inclination angle exceeds the threshold value,
With
In the first step,
The measurement cycle of the measurement data is shorter than half of the vibration cycle due to the resonance of the measurement object.
Inclination monitoring method for columnar structures . The first step of measuring the inclination of the object to be measured and obtaining the measurement data,
A second step of performing averaging processing on a plurality of the measurement data to generate processed data,
The third step of calculating the inclination angle of the measurement object based on the processing data,
Fourth step of comparing the calculated tilt angle with the threshold value,
Fifth step of notifying the occurrence of inclination when the inclination angle exceeds the threshold value,
With
After the first step,
LPF processing is performed to block the frequency region above a predetermined value in the measurement data.
After that, the second step is performed.
Inclination monitoring method for columnar structures . The first step of measuring the inclination of the object to be measured and obtaining the measurement data,
A second step of performing averaging processing on a plurality of the measurement data to generate processed data,
The third step of calculating the inclination angle of the measurement object based on the processing data,
Fourth step of comparing the calculated tilt angle with the threshold value,
Fifth step of notifying the occurrence of inclination when the inclination angle exceeds the threshold value,
With
After the first step,
A process of determining the size of the measurement data and excluding the measurement data of a predetermined size based on the physical interference with the measurement object is performed.
After that, the second step is performed.
Inclination monitoring method for columnar structures .

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