JP2022191271A - Remote state monitoring system and monitoring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote state monitoring system which utilizes a radio line and is able to transmit the amount of data necessary to grasp the circumstances of a structure to a remote monitoring section even if there are restrictions specific to the radio communication system, i.e., having less amount of data.

SOLUTION: A remote state monitoring system 10 comprises an information gathering part 12 for gathering information on the status of the structure, and a monitoring part 14 connected through a communication line 16 and monitoring the structure remotely. The information gathering part 12 is provided with sensor parts which measure data indicative of a physical quantity, and outputs at least one of pieces of information indicative of the distortion amount or abnormal state if the distortion amount exceeds a predetermined value.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a remote condition monitoring system and monitoring method.

2. Description of the Related Art Conventionally, for preventive maintenance of a structure, there has been known a technique of performing measurements at predetermined locations of the structure and monitoring the state of the structure.

Patent Literature 1 below discloses a state monitoring system that includes an acceleration sensor that is provided on a bridge pier to measure acceleration and an information processing device that evaluates the soundness of the pier based on a vibration waveform obtained by analyzing the acceleration. It is

Patent Literature 2 listed below discloses a measurement system that includes a child device provided at a measurement location and a parent device that communicates with the child device via wireless. The child device includes sensors that measure physical quantities such as strain, displacement, and acceleration, a wireless communication unit that transmits information on each physical quantity detected by the sensors to the parent device, and a battery that supplies power to the sensors and transmission means. have.

In the following Patent Document 3, a plurality of acceleration sensors installed in a structure to detect displacement, an arithmetic device for evaluating fatigue based on the displacement detected by the acceleration sensor, and connected to the arithmetic device via the Internet, A preventive maintenance monitoring system and display means for displaying calculation results are disclosed.

JP 2015-230206 A JP-A-2008-234361 JP 2015-98686 A

In conventional remote condition monitoring systems, mobile phone lines such as 3G and LTE are used to remotely transmit information indicating the condition of structures. Such conventional cellular telephone lines are highly reliable and available, but the call charges and communication equipment costs are high. In the Internet of Things (IoT), the number of devices communicating with each other increases, so there is a problem that communication costs increase.

In addition, since communication by conventional mobile phone lines consumes a large amount of power, the capacity of the battery built into the device increases, resulting in the problem that the size of the device itself increases.

Recently, a power-saving wide area wireless network service has attracted attention as a next-generation wireless communication standard for the IoT era, and demonstration experiments have been conducted. The power-saving wide-area wireless network service is a service using a wireless communication technology called, for example, LPWA (Low Power Wide Area). By using the power-saving wide-area wireless network service, low cost, low power consumption, and long-distance communication become possible. However, since this wireless communication service has a low transmission rate and a small size of data to be transmitted and received, there is a problem that it is not possible to remotely transmit all structure information indicating the state of a structure as in the past.

In addition, we were still not fully satisfied with the stable transmission of data in places such as mountainous areas and isolated islands where it is difficult to share a power supply.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a remote condition monitoring system and a monitoring method capable of satisfactorily monitoring the condition of a structure from a distance using a radio line.

The remote condition monitoring system of the present invention comprises an information collection unit provided in a structure for collecting information on the condition of the structure, and a monitoring unit connected to the information collection unit via a communication line for remotely monitoring the structure. In the remote condition monitoring system comprising: a first communication unit that transmits data to the monitoring unit; the monitoring unit stores data received by the second communication unit, and a second communication unit that receives data from the information collection unit; a storage unit, and an information extraction unit that extracts information indicating the state of the structure based on the data stored in the storage unit, the sensor unit includes a strain sensor that measures a strain amount, The data processing unit extracts the strain amount at a predetermined time, and the information extracting unit provides that the data extracted by the data processing unit has a predetermined deviation from the distribution of the past strain amount change region, It is characterized by outputting at least one of information indicating an abnormal state.

A remote condition monitoring system of the present invention includes a plurality of information collection units provided in a structure for collecting information on the condition of the structure, and the information collection units connected to the information collection units via communication lines to remotely monitor the structure. and a monitoring unit, wherein the information collecting unit includes a sensor unit that measures strain amount, an acceleration sensor unit that measures acceleration, and data measured by the sensor unit and the acceleration sensor unit. a data processing unit that processes data; and a first communication unit that transmits data processed by the data processing unit to the monitoring unit. The monitoring unit receives data from the plurality of information collecting units. a communication unit; a storage unit that stores data received by the second communication unit; and an information extraction unit that extracts information indicating the state of a structure based on the data stored in the storage unit. , the sensor unit includes a strain sensor that measures the amount of strain, the information extraction unit compares the data of the strain sensors that measure the amount of strain in the plurality of information collecting units, and the deviation between the data is a predetermined value When the value exceeds the value, at least one of information indicating an abnormal state is output.

According to the remote condition monitoring system and monitoring method of the present invention, it is possible to satisfactorily monitor the condition of a structure from a remote location using a wireless line. Moreover, even if there is a limitation peculiar to the wireless communication system that the amount of communication data is small, it is possible to transmit the data necessary for grasping the situation of the structure to the remote monitoring unit. In addition, data can be stably transmitted to the monitoring unit even in a remote location where it is difficult to secure a power source.

Also, based on the data at a predetermined time sent from the information collecting unit, it is possible to grasp the damage or defect of the structure or the time leading up to these. Therefore, it is possible to respond quickly to repairs (post-maintenance) and to formulate an appropriate repair plan for preventive maintenance to prevent accidents from occurring. In addition, planning of maintenance (regular maintenance) inspection timing, inspection items, inspection points, etc. is also improved.

It is a figure which shows the structure of the remote condition-monitoring system which concerns on this embodiment. It is a flow figure showing a flow of a monitoring method using a remote state monitoring system.

Embodiments of a remote condition monitoring system and a monitoring method will be described below with reference to the drawings. In addition, it is not limited to the following embodiments.

FIG. 1 is a diagram showing the configuration of a remote condition monitoring system 10. As shown in FIG. The remote condition monitoring system 10 remotely monitors the condition of structures (not shown) such as buildings, bridges, tunnels, equipment, ships, utility poles, traffic control facilities, soil structures, roads, pipes, and pipelines. System. This system is used to grasp the state and progression of deterioration over time of structures, to prevent accidents, to grasp the extent and extent of damage during earthquakes, disasters, and fires, to prevent accidents, preventive maintenance, and formulate construction plans. The remote condition monitoring system 10 will be simply referred to as system 10 hereinafter.

The system 10 is provided in a structure and has an information collection unit 12 that collects information about the state of the structure and a monitoring unit 14 that remotely monitors the structure. The information collecting section 12 and the monitoring section 14 are connected via a communication line 16 . The information collecting unit 12 is a so-called IoT device, and is installed singularly or plurally, and transmits measurement data output from various sensors to the monitoring unit 14 .

The communication line 16 is a power-saving wide-area wireless communication line LPWA such as SIGFOX (registered trademark), LoRa (registered trademark), NB-IoT, NB-Fi Protocol, GreenOFDM, DASH7, RPMA, Wi-SUN, and LTE-MTC. (Low Power Wide Area)), Bluetooth (registered trademark), Wi-Fi (registered trademark), EnOcean (registered trademark), ZigBee (registered trademark) and other short-range wireless communication methods, cellular LPWA, communication 3G and There is a communication line of a mobile phone line such as LTE. For example, SIGFOX has a long transmission distance of several tens of kilometers, a very low transmission speed of 100 bps (uplink), and a data size of 12 bytes (uplink), which is less than 1/100 of Ethernet data. .

The information collecting unit 12 includes, as a sensor unit 18 that measures data indicating a physical quantity, a strain sensor 28 that measures strain, an acceleration sensor 30 that measures acceleration, a temperature sensor 32 that measures temperature, and the sensor unit 18 measures A data processing unit 20 that processes data, a first communication unit 22 that transmits data processed by the data processing unit 20 to the monitoring unit 14, a timer unit 24 that has a timekeeping function, and each device in the information collection unit 12 and a power supply 26 for supplying power.

The strain sensor 28 is a sensor that measures the strain amount of the structure, that is, the physical quantity of strain and displacement, and is, for example, a strain gauge. The acceleration sensor 30 is a sensor that measures vibration information of a structure, and is a single-axis or multi-axis accelerometer capable of detecting minute vibrations. The temperature sensor 32 is a sensor that measures the temperature of the structure, such as a thermistor. The sensor unit 18 may include an angle sensor, an acoustic sensor, an ultrasonic sensor, a humidity sensor, a GPS sensor, and a distance sensor (not shown).

The data processing unit 20 processes the data measured by the sensor unit 18 into data that can be used for the communication line 16 and data that can grasp the state of the structure. Specifically, the data processing unit 20 extracts the strain amount, acceleration, and temperature at a predetermined time. Moreover, when the humidity is also measured, the data processing unit 20 also extracts the humidity at a predetermined time.

The first communication unit 22 is a communication interface having a chip on which an application for realizing communication with the communication line 16 is mounted and an antenna. As an example, communication contents when the communication line 16 is SIGFOX will be described. SIGFOX is currently limited to 12 bytes of data at one time. Each data indicating a physical quantity in this embodiment has 3 bytes for strain amount, 2 bytes for acceleration of one axis, and 2 bytes for temperature. In this case, all data can be transmitted in one communication. In addition, if the acceleration and humidity on two axes are used as data indicating the physical quantity, 6 bytes will be added. In this case, all data is transmitted by dividing into two communications.

The timer section 24 can arbitrarily set the above-described predetermined time, and outputs a control signal to the data processing section 20 at that time. The predetermined times may be twice a day, day and night, three or more times a day, or once every few days.

The power supply unit 26 only needs to supply power to the data processing unit 20, the first communication unit 22, and the timer unit 24. The power supply unit 26 is a combination of a power generation function that generates power from external energy and a battery, and converts the vibration of the structure into power. Piezoelectric elements, heat conversion elements that convert heat into electric power, detachable dry cells, solar cells, and dye-sensitized solar cells can be used. The power supply unit 26 is preferably an independent power supply that does not require wiring or charging.

Next, a device for remotely monitoring a structure will be described. The monitoring unit 14 is connected to a terminal (not shown) of a user who uses this system via a wired or wireless communication line. Based on this, the state of the structure can be grasped. The monitoring unit 14 includes a second communication unit 34 that receives data from the information collection unit 12, a storage unit 36 that stores the data received by the second communication unit 34, and based on the data stored in the storage unit 36, and an information extraction unit 38 for extracting information indicating the state of the structure.

The second communication unit 34, like the first communication unit 22, is a communication interface having an antenna and a chip on which an application for realizing communication with the communication line 16 is mounted. receive.

The storage unit 36 is a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like. The storage unit 36 stores the above-described various data sent from the information collection unit 12 . Further, when the sensor unit 18 includes a temperature and humidity sensor, humidity data is also stored. Further, the storage unit 36 can store the data sent from the information collection unit 12 as correlation data indicating the correlation between the amount of strain and the acceleration. The storage unit 36 can also store the calculation result of the information extraction unit 38, an OS (Operating System), various application programs, and the like.

The information extraction unit 38 calculates various data stored in the storage unit 36 and outputs information indicating the state of the structure. Further, the information extractor 38 can directly use the data sent from the information collector 12 for calculation.

When the strain amount exceeds a predetermined value, the information extractor 38 outputs at least one of the strain amount and information indicating an abnormal state. The predetermined value is a strain amount that causes a defect such as a crack at the location where the information collecting unit 12 is provided. The information indicating the abnormal state is information that can be recognized by the user, such as text information. Thereby, it is possible to remotely grasp that a defect has occurred. Further, when the degree of progress of damage at the above location is known from past data, it is also possible to set the amount of strain before reaching the damage as the predetermined value. As a result, accidents can be prevented.

Further, the information extracting section 38 can calculate the displacement amount based on the strain amount and the gauge length of the strain sensor 28 stored in the storage section 36 . Then, when the amount of displacement exceeds a predetermined value, the information extracting section 38 can output at least one of the amount of displacement and information indicating the abnormal state. In this case, the predetermined value is an amount of displacement that causes a defect such as a crack at the location where the information collecting unit 12 is provided. The displacement amount is stored in the storage unit 36 and can be used as an alternative parameter for the strain amount.

The information extraction unit 38 can also calculate an approximate curve based on the past strain amount stored in the storage unit 36, and calculate the time to reach the predetermined value from the curve. By grasping the degree of damage and the time of damage, it is possible to make a repair plan with sufficient margin and just enough.

Further, the information extraction unit 38 extracts the correlation between the strain amount and temperature, the correlation between the strain amount and humidity, the strain amount and temperature/humidity correlation, and the strain amount and acceleration correlation at a predetermined time. It is mapped and stored in the storage unit 36 . This operation is performed each time new data is sent from the information collecting unit 12, and each mapping is overwritten.

Then, if the strain amount and the temperature sent from the information collecting unit 12 have a predetermined divergence from the past correlation between the strain amount and the temperature, the information extracting unit 38 extracts the correlation or the abnormal state. Output at least one of the information shown. Information indicating the correlation is a table, a graph, or the like. The amount of strain usually changes in response to temperature changes on a daily or seasonal basis. In addition, due to aged deterioration of the structure, the amount of change in the amount of strain and the trajectory of the change are different from those in the past, or the distribution of the change area of the amount of strain is different from that in the past. For such differences, thresholds or areas are provided on the correlation mapping, and when the latest data exceeds the set predetermined values, it is treated as a predetermined divergence, and information indicating an abnormal state by the information extraction unit 38. is output as Since the predetermined value as the predetermined deviation is unique to the structure, it can be arbitrarily set by analyzing the data up to the point of damage during operation. This makes it possible to remotely recognize that the structure has been damaged or that there is a risk of damage. Humidity or temperature and humidity can be used instead of temperature, which is one of the correlation parameters. This is because the amount of strain usually changes according to changes in humidity or temperature/humidity on a daily or seasonal basis. If there is a predetermined divergence compared to the correlation between the past strain amount and the humidity or the past correlation between the strain amount and the temperature/humidity, the information extracting unit 38 extracts at least one of the correlation or the information indicating the abnormal state. Output. The method of setting the threshold value or the area on the correlation mapping and the method of outputting the information indicating the abnormal state are the same as when the parameter is the temperature. This makes it possible to remotely recognize that the structure has been damaged or that there is a risk of damage.

In addition, when the strain amount and the acceleration sent from the information collecting unit 12 have a predetermined divergence compared to the past correlation between the strain amount and the acceleration, the information extracting unit 38 extracts the correlation or the abnormal state. output the information shown. The data indicating the correlation are tables, graphs, and the like, and the data (hereinafter referred to as correlation data) are stored in the storage unit 36 . There is a certain correlation between the amount of strain and acceleration, and there is a tendency for the amount of strain to increase as the acceleration increases. As the structure ages, the relationship between strain and acceleration is plotted in a region different from the past correlation region. A threshold value or a boundary line is provided at the outer edge of the past correlation area, and when the latest correlation data exceeds the set predetermined value, it is treated as a predetermined divergence, and the information extraction unit indicates an abnormal state. to output Since the predetermined value as the predetermined deviation is unique to the structure, it can be arbitrarily set by analyzing correlation data up to the point of damage during operation. This makes it possible to remotely recognize that the structure has been damaged or that there is a risk of damage.

In addition, the information extraction unit 38 compares the correlation data in the plurality of information collection units 12, and if the divergence between the correlation data exceeds a predetermined value, at least one of the correlation data and the information indicating the abnormal state is extracted. It can also be output. The correlation data described in the previous paragraph relates to the strain amount and acceleration measured by the same information collection unit 12, and the information extraction unit 38 compares this correlation data with the same data in the past, and finds the deviation extracting the situation. On the other hand, the information extraction unit 38 can also compare the correlation data in each information collection unit 12 and extract the divergence state. The correlation data in each information collecting unit 12 also has a certain correlation, and when the structure deteriorates over time, the divergence between the correlation data changes. The information extraction unit 38 outputs information indicating an abnormal state when the divergence exceeds a predetermined value. Since the predetermined value as the predetermined deviation is unique to the structure, it can be arbitrarily set by analyzing the data up to the point of damage during operation. This makes it possible to remotely grasp the state of damage to structures or estimate future damage.

Specifically, the data processing unit 20 detects the occurrence of an earthquake when the measured acceleration is equal to or greater than a predetermined value, processes measurement data at this detection time, and transmits the data to the monitoring unit 14 .

The data processing unit 20 also detects the occurrence of a fire when the measured temperature is equal to or higher than a predetermined value, processes the measurement data at the detection time, and transmits the processed data to the monitoring unit 14 . In these modes, the timer section 24 may be activated by the detection of a disaster as a trigger, and detailed data may be periodically sent to the monitoring section 14 as measurement data in a shorter span than in normal times.

One of the characteristic principles of the present invention utilizes the relationship between stress and strain (deformation) when a structure (solid material) receives an external force. It is to quantify and compare with the amount of change due to temperature, humidity, environment, etc. Degradation of structures generally progresses due to external forces, chemical reactions, creep, heat, and the like. Therefore, the amount of change in the state of deterioration, that is, the amount of change is continuously monitored using the laws of physics. In this way, it is expected to be used for various purposes such as grasping or estimating the state of damage by analyzing and analyzing huge amounts of long-term data.

Structures include concrete, plastic, and metal. Accuracy is improved by using correlation data between strain and acceleration sensors for structures that are subject to external forces such as vibration, and using correlation data between strain and temperature or humidity for static structures. Good in terms of If the surface of the structure is coated with a coating agent, the strain sensor 28 is attached to the structure via an adhesive after removal.

Next, one aspect of the remote condition monitoring method using the system 10 will be described with reference to FIG.

First, in step S01, the sensor unit 18 provided in the structure measures data indicating a physical quantity. Specifically, the strain sensor 28 measures strain, the acceleration sensor 30 measures acceleration, and the temperature sensor 32 measures temperature.

In step S02, the data processing unit 20 processes the measured data. Specifically, the data processing unit 20 extracts the strain amount, acceleration, and temperature at a predetermined time.

Then, in step S03, the first communication unit 22 transmits the processed data to the remote monitoring unit 14, and in step S04, the second communication unit 34 in the monitoring unit 14 receives the transmitted data. do. Then, in step S05, the storage unit 36 stores the received data.

Finally, in step S<b>06 , the information extractor 38 extracts information indicating the state of the structure based on the data stored in the memory 36 . Specifically, when the strain amount exceeds a predetermined value, information indicating the strain amount or the abnormal state is output.

The present invention is not limited to the configuration shown in FIG. 1 as long as the system 10 has a function capable of executing the monitoring method described above. The above series of steps can be executed by hardware or by software. Also, one functional block may be composed of hardware alone, software alone, or a combination thereof. Also, the monitoring unit 14 of the present embodiment is not limited to the configuration described above, and at least part of the functions may be operated by an application installed in the user's terminal.

It is also possible to extract the maximum value of acceleration in a time period of several minutes including the predetermined time. When the number of detection axes of the acceleration sensor 30 is three, measurement values are extracted for each axis. In this case, the amount of communication data increases, so the first communication unit 22 divides the data into multiple transmissions. As a result, the monitoring unit 14 can grasp the state of the structure in more detail.

The data processing unit 20 can also calculate the natural frequency of the structure based on the measured acceleration and transmit the data to the monitoring unit 14 . The monitoring unit 14 can detect an abnormal state of the structure from changes in the natural frequency due to aged deterioration or damage of the structure.

In this embodiment, the configuration may be such that two-way communication is possible between the first communication unit 22 and the second communication unit 34 . With this configuration, the processing content of the data processing unit 20 can be changed from the monitoring unit 14 . A predetermined time in the timer section 24 can also be set from the monitoring section 14 .

In this embodiment, the user can view or download necessary information or history by accessing the monitoring unit 14 . As a result, even before the structure reaches an abnormal state, the user can grasp the deterioration tendency of the state of the structure.

10 remote condition monitoring system, 12 information collecting unit, 14 monitoring unit, 16 communication line, 18 sensor unit, 20 data processing unit, 22 first communication unit, 24 timer unit, 26 power supply unit, 28 strain sensor, 30 acceleration sensor, 32 temperature/humidity sensor, 34 second communication unit, 36 storage unit, 38 information extraction unit.

Claims (6)

a plurality of information collecting units that are provided in the structure and collect information about the state of the structure;
a monitoring unit connected to the information collecting unit via a communication line and remotely monitoring the structure;
In a remote condition monitoring system having
The information collection unit
a sensor unit that measures the amount of strain;
a data processing unit that processes data measured by the sensor unit;
a first communication unit that transmits data processed by the data processing unit to the monitoring unit;
has
The monitoring unit
a second communication unit that receives data from the information collection unit;
a storage unit that stores the data received by the second communication unit;
an information extraction unit that extracts information indicating the state of a structure based on the data stored in the storage unit;
has
The sensor unit includes a strain sensor that measures the amount of strain, and the information extraction unit compares the data of the strain sensors that measure the amount of strain in the plurality of information collecting units, and the deviation between the data is a predetermined value. If it exceeds, output at least one of the information indicating the abnormal state,
A remote condition monitoring system characterized by: The information extraction unit compares the correlation data in each information collection unit, and outputs at least one of the correlation data or information indicating an abnormal state when the deviation between the correlation data exceeds a predetermined value. ,
The remote condition monitoring system according to claim 1, characterized in that: The information extraction unit compares the correlation data in each information collection unit with the past correlation data, and outputs at least one of the correlation data or information indicating an abnormal state when the deviation exceeds a predetermined value. do,
The remote condition monitoring system according to claim 1, characterized in that: The information collecting unit has an acceleration sensor unit that measures acceleration,
The remote condition monitoring system according to claim 1, characterized in that: The information collecting unit has a humidity sensor unit that measures humidity,
The remote condition monitoring system according to claim 1, characterized in that: The information collecting unit has a temperature sensor unit that measures temperature,
The remote condition monitoring system according to claim 1, characterized in that:

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