JP2018004387A - Gradient monitoring system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system correctly measuring an acceleration applied to an electric pole, efficiently collecting measurement data from a large number of electric poles scattering in the wide area, and detecting the generation of gradients at an early stage.SOLUTION: A sensor node installed on a pole of an electric pole acquires a value of acceleration in a prescribed number of times from a built-in acceleration sensor capable of measuring accelerations in a plurality of directions, performing averaging processing for each direction where a series of acceleration data is measured, and calculating the acceleration applied to the electric pole. The sensor node transmits the calculated acceleration data to a gateway installed in the vicinity of the electric pole via a short-range wireless communication. The gateway transmits the received acceleration data to a server via a long-distance wireless communication. The server accumulates the received acceleration data in a database, and determines whether or not the maximum value of the an inclination angle calculated from the received acceleration data exceeds a threshold value set beforehand for each electric pole. When the inclination angle exceeds the threshold value, the server determines that the electric pole is in an abnormal state, and notifies the fact to the destination of an administrator registered beforehand.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an inclination monitoring system and method applied to a structure such as an electric pole, a bridge, a house, a building, and the like that may be inclined over time.

  For example, telephone poles have been installed throughout the town, but there are cases where slopes occur due to natural phenomena such as earthquakes and human activities such as construction and maintenance of electric wires. If an inclination occurs and proceeds, a collapse accident may occur. In order to prevent collapse, it is important to check the slope regularly.

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

JP 2006-133230 A JP 2004-147374 A

  It is important to detect and deal with the occurrence of tilt at an early stage in order to prevent a telephone pole collapse accident. On the other hand, a business operator who manages a power pole generally manages a large number of power poles scattered over a wide area over 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 achieves efficient inspection, but it is still necessary for an operator to go to the worksite of the utility pole and collect data, Requires a lot of labor and cost.

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

  One aspect of the present invention that solves the above problems is an inclination monitoring system including a sensor node and a server. In this system, the sensor node includes a sensor that measures the inclination of the measurement object, 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 that transmits the processing data recorded in the recording unit. The server also includes a receiving unit that receives the processing data transmitted from the sensor node, a storage unit that stores the processing data received by the receiving unit, and an inclination angle of the measurement object based on the processing data stored in the storage unit. An inclination angle calculation unit to be calculated, a determination unit that determines whether there is an inclination based on the inclination angle calculated by the inclination angle calculation unit, and a notification unit that notifies the occurrence of an inclination when the determination unit determines that there is an inclination.

  Another aspect of the present invention that solves the above problem is a first step of measuring the inclination of a measurement object to obtain measurement data, averaging the plurality of measurement data, and processing data Second step to be generated, third step to calculate the tilt angle of the measurement object based on the processing data, fourth step to compare the calculated tilt angle with the threshold value, and occurrence of tilt when the tilt angle exceeds the threshold value A tilt monitoring method comprising: a fifth step of notifying

  ADVANTAGE OF THE INVENTION According to this invention, the inclination | tilt angle of many structures scattered in the wide area, for example, a utility pole, can be managed efficiently and exactly, and generation | occurrence | production of inclination can be detected 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 a sensor node. It is a graph which shows the example of the fluctuation | variation of measurement data and average data. It is a table | surface figure which shows the example of the numerical value of measurement data and averaged data. It is a table | surface figure which shows the structural example of the transmission data of a sensor node. It is a block diagram which shows the example of a structure of a gateway. It is a block diagram which shows the example of a structure of a server. 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 operation | movement of an inclination monitoring system. It is a graph which shows the fluctuation | variation of the acceleration concerning a utility pole installation in case resonance arises, and the example of measurement data. It is a conceptual diagram which shows the example of the fluctuation | variation of the acceleration concerning a utility pole installation in case train vibration generate | occur | produces. It is a graph which shows the example of the fluctuation | variation of the acceleration concerning a utility pole installation in case a big vibration generate | occur | produces, and measurement data. It is a block diagram which shows the example of the block diagram of the sensor node in Example 4. FIG. 10 is a flowchart illustrating an operation when performing threshold determination processing according to the fourth embodiment. FIG. 10 is a plan view illustrating an example of a server screen display according to the fifth embodiment.

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

  In the embodiments, when there are a plurality of components that can be regarded as equivalent, the same reference numerals may be added with a suffix to distinguish them. However, if there is no need to distinguish between them, the suffix may be omitted.

  The position, size, shape, range, and the like of each component illustrated in the drawings and the like may not represent the actual position, size, shape, range, or the like in order to facilitate understanding of the invention. For this reason, the present invention is not necessarily limited to the position, size, shape, range, and the like disclosed in the drawings and the like.

  When the present inventors continuously monitor the inclination angle of the utility pole, the inventors paid attention to that the inclination angle is not constant because the utility pole is frequently shaken under the influence of the surrounding environment. Specific examples of shaking due to the influence of the surrounding environment include, for example, shaking caused by the natural environment such as rain and wind, and shaking caused by ground vibration that occurs when a train or the like passes nearby. And the inventors, the inclination angle of the utility pole is a mixture of a component representing the degree of inclination of the utility pole itself as a structure and a temporary fluctuation component generated by a phenomenon caused by the surrounding environment, Newly found. In particular, it is necessary to detect a minute inclination angle of about 0.5 degrees for the early detection of the inclination. However, the fluctuation due to the influence of the surrounding environment is also the same degree, and it is difficult to distinguish it.

  Based on this new knowledge, in order to accurately calculate the inclination angle of the utility pole itself, the basic configuration of the inclination monitoring system according to the embodiment described below includes an acceleration sensor that measures the inclination of the measurement object, and A processing unit that performs processing on measurement data acquired by measurement, a recording unit that records processed processing data, a wireless unit that transmits recorded processing data, and a sensor node that is transmitted from the sensor node A communication unit that receives processing data via the gateway, a storage unit that stores the received processing data, an inclination angle calculation unit that calculates an inclination angle of the measurement object based on the accumulated processing data, and a calculated inclination angle And a server that includes a determination unit that determines whether or not there is an inclination and a notification unit that notifies the occurrence of an abnormal inclination when it is determined that there is an inclination.

  An example of processing for measurement data for reducing the influence of noise due to the influence of the surrounding environment is an averaging process.

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

<1. Overall system configuration>
FIG. 1 shows an installation example of the inclination monitoring system in the present 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. Each site 1 has a plurality of utility pole facilities 5 to be measured, and a sensor node 2 is installed for each utility pole facility 5.

  The sensor node 2 has a function of measuring acceleration applied to the utility pole equipment 5. 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.

  Furthermore, the gateway 3 provided with a relay function is installed for every field 1a, 1b, 1c. The gateway 3 receives 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 short-range wireless (for example, communicable distance is 100 m) does not reach, a plurality of gateways 3 may be installed. The gateway 3 may be installed in a fixed storage facility or the like, or may be carried and moved 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. As a transmission method from the gateway 3 to the wide area network 6, for example, a long-distance wireless (for example, a communicable distance is 1 km or more) can be mentioned. For this purpose, the wide area network 6 is connected to a long-distance wireless receiving facility (not shown).

  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 an inclination angle from the aggregated acceleration measurement data, and monitors the inclination state of each utility pole equipment 5. When the inclination angle exceeds a preset threshold value, the server 4 notifies the administrator 7 by notification means such as e-mail. As a threshold value, for example, notification is performed at an inclination of 5 degrees, and in this case, the resolution of the inclination angle measurement may be about 0.5 degrees, for example.

  Further, since the sensor node 2 is installed on a pole on the utility pole facility 5, wiring for power feeding and battery replacement work require labor. In order to realize long-term operation, it is desirable that the sensor node 2 includes a power feeding mechanism configured with a solar panel or the like, and operates with the power. The sensor node 2 is preferably 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 the present 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 wireless 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 have functions as software. Software is installed on the recording unit 22. Hereinafter, functions of each unit will be described.

  The control unit 20 gives data to the acceleration sensor 21, the recording unit 22, the averaging processing unit 23, the short-range wireless unit 24, and the clock unit 26, and issues an operation instruction to control 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 acceleration value applied to the utility pole equipment 5. The acceleration sensor 21 can measure accelerations in a plurality of directions such as north-south direction and east-west direction. The configuration for measuring the acceleration is disclosed in, for example, Patent Document 1. An acceleration sensor using MEMS (Micro Electro Mechanical Systems) is also 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 averaged data described later. Various storage devices can be used for the recording unit 22. For example, a nonvolatile semiconductor memory such as a flash memory can be used.

  The averaging processing unit 23 performs an averaging process for calculating an average value from acceleration data. Here, the effect of the averaging process will be described. In the inclination angle of the utility pole, there are a mixture of a component representing the degree of inclination of the utility pole itself (hereinafter referred to as a slope component) and a temporary fluctuation component (hereinafter referred to as a fluctuation component) generated by a phenomenon caused by the surrounding environment. ing. For example, a fluctuation component of about 0.5 degrees is generated when the utility pole is pulled by vibration of the overhead wire due to 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 variation when a tilt angle variation component occurs. Time is taken on the horizontal axis, and acceleration is taken on the vertical axis. As shown in FIG. 3, the measurement data indicated by black circles has a shape in which an acceleration fluctuation component is superimposed on an acceleration inclination component.

FIG. 4 shows an example of measured values. When vibration occurs, measurement data (for example, 0.98) deviating greatly from the tilt component is generated. Here, the value obtained by performing the averaging process on the measurement data (hereinafter referred to as averaged data) can be defined by the following Equation 1 for convenience.
ai + (1 / N) Σbi (Formula 1)

  ai is a slope component of acceleration, bi is a fluctuation component of acceleration, and N is the number of measurement data to be averaged. As the number of data to be averaged increases, the fluctuation component can be reduced. In the case where 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 averaged data from the measurement data of about several minutes. For example, when measurement data of about 8 minutes is set as an averaging target, the fluctuation component of acceleration due to the vibration can be sufficiently reduced while a 15-car train passes in the vicinity. Specifically, it is obtained by (train length (m) ÷ travel speed V (m / s)) × safety factor 30 or the like. 25 m × 15 ÷ 24 × 30 times = about 8 minutes.

  The averaged data obtained by performing the averaging process on 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 in which the influence of vibration is reduced as compared with the conventional case where the tilt angle is calculated from the measurement data of the acceleration sensor 21.

  Also, by transmitting the averaged data (white circle in FIG. 3) by the averaging process, it is possible to obtain an effect of compressing the communication amount as compared to transmitting the measurement data (black circle 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 averaged 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 by executing a program stored in the recording unit 22 by a processing device (not shown) alone. Realized. A program executed by a computer, its function, or means for realizing the function may be referred to as “function”, “means”, “unit”, “unit”, “module”, or the like.

  A function equivalent to a function configured by software can be realized by hardware such as an FPGA (Field Programmable Gate Array) and an ASIC (Application Specific Integrated Circuit).

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

  At this time, the short-range wireless unit 24 holds an identification ID (such as a MAC address) 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 wireless unit 24 includes average data corresponding to each axis such as sensor node identification ID, xyz of the acceleration sensor, and measurement time. Here, when the size of the transmission data can be increased, the operation information of the sensor node 2 may be transmitted at the same time. For example, if the supply voltage value of the power supply unit 27 and past measurement data history are transmitted at the same time, it is useful for operation management of the sensor node 2. The antenna 25 has a function of transmitting short-range radio waves. Further, a reception 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 an external signal.

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

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

  The control unit 30 has a function of controlling the short-range wireless unit 31 and the long-range wireless 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 similarly to the control unit 20 of the sensor node 2.

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

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

  The long-distance wireless unit 33 has a function of communicating with the server 4 through the long-distance wireless antenna 34. The gateway 3 and the server 4 are separated from each other. Therefore, the communication is performed via the wide area network 6, wireless communication between the gateway 3 and the wide area network 6, and wired communication between the wide area network 6 and the server 4. The timing at which the long-distance radio unit 33 operates may be synchronized with the reception of the averaged data of the short-distance radio unit 31. However, a storage area is provided in the long-distance radio unit 33 or the like and temporarily stored in the buffer. You may send it with

  The long-distance radio antenna 34 has a function of transmitting a long-distance radio wave. Further, a reception function may be provided.

  The power supply unit 35 has a function of supplying 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 the present 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. Hereinafter, functions of each unit will be described.

  The control unit 40 has a function of controlling the communication unit 41, the storage unit 42, the tilt angle calculation unit 43, the tilt threshold determination unit 44, the notification unit 45, and the 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 similarly to 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 separated from each other. Therefore, communication goes through the wide area network 6. Therefore, the communication unit 41 includes an interface for connecting to the wide area network 6 such as the Internet.

  The accumulating unit 42 accumulates the averaged data transmitted from the sensor node 2. The averaged data is organized and stored 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 tilt angle calculation unit 43 has a function of calculating the tilt direction in which the utility pole equipment 5 is tilted most and the tilt angle from the averaged data stored in the storage unit 42. For example, when the acceleration sensor can acquire the biaxial accelerations Ax and Ay of the x axis and the y axis, the method of calculating the inclination direction and the inclination angle from the acceleration can be calculated by the following formula. The symbol “^ 2” indicates square. g is a gravitational acceleration.
Inclination 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 inclination to a terminal used by one or more managers 7 registered in advance. As the notification means, it may be notified to the mail address of the administrator's terminal by electronic mail, or may be displayed on the liquid crystal display of the terminal. The information to be notified preferably includes at least identification information of the utility pole equipment 5 and information on the inclination angle.

  Like the control unit 40, the tilt angle calculation unit 43, the tilt threshold determination unit 44, and the notification unit 45 can be configured by software or hardware.

  The screen display unit 46 has a function of displaying the notification from the notification unit 45. Moreover, the function which displays the condition of the utility pole equipment 5 preserve | saved at the storage part 42 according to a manager's request | requirement is provided.

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

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

  The control unit 20 of the sensor node 2 reads time information from the clock unit 26 and determines whether it is a measurement time (501). Here, when the control unit 20 determines that the measurement time is predetermined (Yes in 501), the acceleration sensor 21 measures the acceleration applied to the utility pole equipment 5 (502). Since the acceleration sensor 21 can measure accelerations in a plurality of directions, the acceleration sensor 21 performs measurement for each direction and records measurement data in the recording unit 22.

  When the number of measurement data reaches the predetermined number of times N (Yes in 503), the control unit 20 sends the measurement data to the averaging processing unit 23. The averaging processing unit 23 performs an averaging process on the measurement data for each measurement direction (504). At the same time, the control unit 20 acquires time information from the clock unit 26 and records it in the recording unit 22 together with the averaged data (505). On the other hand, when the number of measurement data is less than the predetermined number N of measurement times (No in 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 time information from the clock unit 26 and determines whether it is a transmission time (506). If it is not the transmission time (No in 506), the control unit 20 finishes the process and waits for the next measurement time.

  If it is the transmission time (Yes in 506), the control unit 20 extracts the latest averaged data from the recording unit 22 (507), and instructs the short-range wireless unit 24 to transmit (507). Measurement time intervals and transmission time intervals can be arbitrarily determined. For example, new averaged data can be transmitted every time if it is set so that it can be measured at least N times between the transmission times, but the present invention is not limited to this.

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

  The short-range wireless 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 wireless unit 31 to the long-range wireless unit 33. And the long-distance radio | wireless part 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 averaged data stored in the storage unit 42 to the tilt angle calculation unit 43. The timing for passing the averaged data to the inclination angle calculation unit 43 can be arbitrarily determined. For example, every time the data transmitted by the gateway 3 is received, the latest averaged data may be passed to the inclination angle calculation unit 43, but the present invention is not limited to this.

  The inclination angle calculation unit 43 calculates the direction in which the utility pole equipment 5 is most inclined and the inclination angle from the averaged data, and records them 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 determination unit 44 ends the process without raising an alarm of occurrence of an abnormal tilt.

  When the calculated tilt angle, for example, the maximum tilt angle, exceeds a preset threshold value (Yes in 513), the tilt threshold value determination unit 44 sends an alarm of 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, for example, the notification unit 45 notifies the administrator 7 of the occurrence of the inclination (514).

  As described above, according to the present embodiment, by performing an averaging process on the acceleration value measured by the sensor node 2, the fluctuation component can be reduced and the inclination component of the utility pole itself can be extracted. . Since the server 4 monitors the presence / absence of abnormality based on the inclination degree of the utility pole itself using the averaged data with reduced fluctuation components, the mere inclination of the utility pole that does not reduce the fluctuation components as in the prior art. Compared with the monitoring of the presence / absence of abnormality based on the corners, monitoring with higher accuracy is possible.

  The fluctuation component of the inclination angle causes an erroneous determination when a system for detecting a sign of collapse of a utility pole is constructed. For example, when an abnormal alert is given based on the measured tilt angle as in the prior art, there is a concern that a fluctuating component due to vibration is erroneously recognized as the occurrence of tilt, and false alarms are frequently generated. On the other hand, in the system to which the present embodiment is applied, since there is no abnormality in the inclination angle of the utility pole based on the averaged data with reduced fluctuation components, there are problems such as frequent alerts due to fluctuation components. Can be solved.

  Further, the averaging process reduces the amount of information of measurement data, and enables the sensor node 2 to reduce power consumption. In addition, by adopting a data collection method in which the short distance radio and the long distance radio are combined by the gateway 3, the acceleration applied to a large number of utility poles scattered in a wide area is efficiently collected. According to the present embodiment, it is possible to construct a tilt monitoring system that accurately detects the occurrence of a tilt and raises an alert, thereby preventing a collapse accident in advance.

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

  If there are other structures around the measurement object, resonance may occur. For example, in a utility pole installed in the vicinity of a viaduct, when the resonance frequency of the viaduct and the utility pole coincide, vibration with a large amplitude occurs due to a 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 period of the inclination angle. 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 knowledge, a means for improving the inclination monitoring accuracy will be described as a second embodiment. The influence of the resonance phenomenon will be described below.

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

Therefore, the influence of the fluctuation component is reduced by adjusting the measurement cycle of the acceleration sensor 21 of the sensor node 2. Specifically, the measurement cycle Ts of the acceleration sensor 21 is set so as to satisfy the following formula.
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 gradient component but also a value smaller than the gradient component.

  For example, in the example of FIG. 10, the measurement cycle (Ts) = half the vibration cycle (1 / (2 · Fp)). In this example, 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, so the larger and smaller values cancel each other out in the averaging process, and the fluctuation component is Can be reduced. Even when the phase of the measurement cycle is shifted, 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 past measurement data number N = 5. The appropriate number of data N to be averaged depends on the environment of the target utility pole equipment and the like, and can be determined by examining past data.

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

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

  In this embodiment, the sensor node 2 holds the setting of the measurement cycle in the recording unit 22. When it is known in advance that the monitored utility pole equipment 5 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 the resonance is found after the sensor node 2 is installed.

  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 monitoring accuracy of the inclination can be increased.

  Utility poles installed near the track are subject to large vibrations that occur during train travel. The inventors of the present invention have focused on the fact that the vibration generated when the train travels 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 knowledge, means for increasing the monitoring accuracy of the tilt will be described as a third embodiment. The vibrations caused by train travel are described below.

  FIG. 11 is a diagram illustrating an example of acceleration variation due to the traveling of the train 110. As shown in FIG. 11A, the main cause of the vibration by the train 110 is the impact of the wheels and the track that occurs when the train 110 passes through the joint 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 distance 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 travel. .

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

  FIG. 11C illustrates the acceleration 702 that is affected by train travel, with the horizontal axis representing frequency and the vertical axis representing acceleration. By removing the frequency band 703 of the frequency F = V / L or more that becomes the peak of vibration, the influence of train traveling can be reduced.

  Based on the above knowledge, the configuration of the tilt monitoring system in the present embodiment will be described. The acceleration sensor 21 of the sensor node 2 has an LPF (Low Pass Filter) processing function inside. In general, an acceleration sensor device is equipped with an LPF processing function for the purpose of suppressing the effects of electrical noise and hand shake when it is held in the hand.

  The LPF process cuts off a high frequency component having a certain frequency or higher. Details of the LPF processing of the acceleration sensor device are well-known depending on products. The acceleration sensor 21 executes LPF processing when acquiring measurement data, and removes the frequency component of train vibration obtained by the above formula.

  The sensor node 2 holds the setting of the cutoff frequency of the LPF process in the recording unit 22. The sensor node 2 may include a mechanism that can change the setting.

  As described above, the acceleration sensor 21 includes the LPF process, and by setting the cut-off frequency of the LPF process to a frequency specific to the vibration factor, the influence of the train traveling vibration is reduced and the inclination monitoring accuracy is increased. be able to.

  By using the LPF process of the third embodiment in combination with the averaging process of the first embodiment, the effect of reducing the acceleration fluctuation component by the averaging process can be increased. Further, in a situation where the cause of the acceleration fluctuation component is limited to a 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 vibration received by the utility pole equipment 5 is too large, the influence 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 illustrating an example of acceleration when momentary large vibration is applied in the first embodiment. The horizontal axis indicates time, and the vertical axis indicates acceleration. Measurement values 901 are obtained discretely. When a large vibration occurs, the sensor node 2 acquires very large measurement data such as the measurement value 901x. The data targeted by the sensor node 2 for averaging processing is the acceleration 902 that has received sudden vibration, which includes the influence of the measurement value 901x that is a fluctuation component. When the number of data for the averaging process is small, the averaged data is greatly affected by the fluctuation component. For such a problem, a method for reducing the fluctuation component will be described below as a fourth embodiment of the present invention.

  FIG. 13 shows a configuration example of the sensor node 2a in the present 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 measurement data held by the recording unit 22 and comparing it with a predetermined threshold value 903 (FIG. 12). The acceleration threshold determination unit 28 holds the setting of the threshold 903 in the recording unit 22. The sensor node 2 may include a mechanism that can change the setting.

  The flowchart of FIG. 14 shows the operation of the tilt monitoring system of this embodiment. Since steps denoted by the same reference numerals as those in FIG. 9 indicate similar operations, 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). If the measurement data is within the threshold (Yes in 502-2), the acceleration threshold determination unit 28 finishes the process and proceeds to step 503. If the measurement data exceeds the threshold (No in 502-2), the acceleration threshold determination unit 28 deletes the measurement data and returns to Step 501.

  As described above, the acceleration threshold value determination unit 28 eliminates measurement data when the measurement data exceeds the threshold value, thereby reducing the influence even when a large vibration occurs and increasing the inclination monitoring accuracy. Can do. In addition, as a threshold value, you may compare with measurement data using a fixed value like FIG. 12, and the difference of the last measurement data and the latest measurement data is calculated, the said difference is compared with a threshold value, and more than a threshold value If the difference is generated, the latest measurement data may be deleted.

  The accuracy of acceleration measurement can be increased by using the processing of the fourth embodiment in combination with the processing of the first to third embodiments. 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, whereby the inclination monitoring accuracy can be further improved. Moreover, even if used alone, a certain effect can be obtained.

  When construction is performed in the vicinity of a utility pole, the probability of occurrence of inclination increases significantly. In particular, when a large number of utility poles incline around the construction site, the repair work requires a great deal of labor. In such a case, it is desirable not to repair after the occurrence of the inclination, but to predict the occurrence of the abnormal inclination in advance and perform the repair at an early stage. For such a problem, prediction of abnormal inclination will be described below as a fifth embodiment of the present invention.

  FIG. 15 is an example of display on the screen display unit 46 of the server 4. The screen display unit 46 displays the sensor node identification ID, measurement time, tilt direction, tilt angle, tilt change rate, and 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 averaged data, and 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 determination unit 44 performs threshold determination on the calculated inclination change rate based on the inclination change rate threshold. When the inclination change rate exceeds the threshold value, the notification unit 45 notifies the manager 7 that there is a high possibility of occurrence of an abnormal inclination.

  As described above, according to the present embodiment, since the abnormal inclination is detected based on the change rate 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 falls within a threshold value but has a possibility of collapsing, and to perform repair work at an early stage.

  According to the embodiment of the present invention, the temporal fluctuation component due to the surrounding environment is reduced with respect to the measured inclination angle of the utility pole, so that the degree of inclination of the utility pole itself can be accurately calculated. . As a result, it is possible to efficiently and accurately manage the inclination angles of a large number of utility poles scattered in a wide area. And according to the Example of this invention, it becomes possible to detect the abnormal state of inclination at an early stage, and to notify an administrator etc. accurately.

  The present invention is not limited to the embodiments described above, and includes various modifications. For example, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace the configurations of other embodiments with respect to a part of the configurations of the embodiments.

DESCRIPTION OF SYMBOLS 1 Field 2 Sensor node 3 Gateway 4 Server 5 Utility pole equipment 6 Wide area network 7 Manager 21 Acceleration sensor 22 Recording part 23 Averaging process part 24 Short-distance radio part 25 Antenna 26 Clock part 27 Power supply part 28 Acceleration threshold value judgment part 31 Short distance Wireless unit 32 Short-range wireless antenna 33 Long-range wireless unit 34 Long-range wireless antenna 41 Communication unit 42 Storage unit 43 Inclination angle calculation unit 44 Inclination threshold determination unit 45 Notification unit 46 Screen display unit

Claims (10)

A tilt monitoring system comprising a sensor node and a server,
The sensor node is
A sensor for measuring the inclination of the measurement object;
A processing unit for processing the measurement data measured by the sensor;
A recording unit for recording processing data processed by the processing unit;
A transmission unit for transmitting the processing data recorded in the recording unit;
The server
A receiving unit for receiving the processing data transmitted from the sensor node;
An accumulation unit for accumulating the processing data received by the reception unit;
An inclination angle calculation unit for calculating an inclination angle of the measurement object based on the processing data accumulated in the accumulation unit;
A determination unit that determines presence or absence of inclination based on the inclination angle calculated by the inclination angle calculation unit;
A notification unit for notifying the occurrence of inclination when the determination unit determines that there is an inclination,
An inclination monitoring system characterized by that. The processor is
Averaging processing is performed using a plurality of the measurement data, and averaged data is calculated as the processing data,
The transmitter is
Sending the averaged data;
The tilt monitoring system according to claim 1. It also has a gateway,
The transmitter is
Wirelessly transmitting the processing data from the sensor node to the gateway;
The gateway is
Transmitting the processing data to the server via a wide area network;
The tilt monitoring system according to claim 1. The sensor is
When the measurement period 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
The inclination monitoring system according to claim 2. The sensor is
LPF processing is performed to block a predetermined frequency region or more of the measurement data.
The tilt monitoring system according to claim 1. The sensor node includes an acceleration threshold value determination unit,
The acceleration threshold determination unit
Determining the size of the measurement data and excluding measurement data of a predetermined size;
The tilt monitoring system according to claim 1. The inclination angle calculation unit
Calculate slope change rate from past accumulated data,
The tilt monitoring system according to claim 1. A first step of obtaining measurement data by measuring the inclination of the measurement object;
A second step of performing an averaging process on the plurality of measurement data to generate process data;
A third step of calculating an inclination angle of the measurement object based on the processing data;
A fourth step of comparing the calculated tilt angle with a threshold;
A fifth step of notifying the occurrence of tilt when the tilt angle exceeds the threshold;
A tilt monitoring method comprising: In the first step,
Shortening the measurement cycle of the measurement data than half of the vibration cycle due to resonance of the measurement object,
The inclination monitoring method according to claim 8. After the first step,
LPF processing to cut off a predetermined frequency region or more of the measurement data,
and,
A process of determining the size of the measurement data and excluding measurement data of a predetermined size;
Do at least one of
Thereafter, the second step is performed.
The inclination monitoring method according to claim 8.

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