JP2017220081A - Sensor device, sensor system and measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a conventional sensor device that power consumption tends to considerably increase.SOLUTION: Provided is a sensor device comprising a sensor unit for measuring the physical quantity of an object, communication unit for communicating with an external device, a timekeeping unit for counting the time of day and a control unit for controlling the sensor unit and the timekeeping unit, the control unit placing the communication unit into a communicatable state, allowing it to receive time of day information from the external device and adjusting the time of day of the timekeeping unit on the basis of the time of day information during a time synchronization period, placing the sensor unit into a measurement possible powered state and allowing it to measure the physical quantity of an object during an observation period, placing the communication unit and the sensor unit into a power-saving state during a power-saving period. Also provided is a sensor system that includes the sensor device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sensor device, a sensor system, and a measurement method.

  In fields such as structural health monitoring systems that detect physical quantities such as vibrations of structures and diagnose structural performance such as damage and aging, each sensor device that detects physical quantities transmits measurement data wirelessly, A computer or a relay device collects measurement data from a plurality of sensor devices (see, for example, Patent Documents 1 and 2).

Patent Document 1 International Publication No. 2013/0999026 Patent Document 2 International Publication No. 2015-087751

  However, the conventional sensor device has a problem that the power consumption is remarkably increased.

  In the first aspect of the present invention, a sensor unit that measures a physical quantity of an object, a communication unit that communicates with an external device, a timer unit that measures time, a sensor unit, and a controller that controls the timer unit The control unit is configured to receive time information from an external device as a power state in which the communication unit can communicate in the time synchronization period, and adjust the time of the timing unit based on the time information, and in the observation period Provided are a sensor device that measures a physical quantity of an object in a power state in which the sensor unit can be measured and sets the communication unit and the sensor unit in a power saving state during a power saving period, and a sensor system including the sensor device.

  In the second aspect of the present invention, the sensor device measures a physical quantity of an object, and the sensor apparatus includes a sensor unit that measures the physical quantity of the object, and a communication unit that communicates with an external device. A time measuring unit that measures time, a sensor unit, and a control unit that controls the time measuring unit, and the measurement method uses time information from an external device as a power state in which the communication unit can communicate during a time synchronization period. And adjusting the time of the timing unit based on the time information, in the observation period, in the observation period, the physical quantity of the object is measured as a measurable power state, and in the power saving period, the communication unit And a step of putting the sensor unit in a power saving state.

  The summary of the invention does not enumerate all the features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a block diagram which shows the sensor system which concerns on this embodiment. It is a timing chart which shows the operation mode of the sensor apparatus concerning this embodiment. It is a flowchart which shows operation | movement of the sensor system which concerns on this embodiment. It is a flowchart which shows the synchronous operation | movement of a sensor apparatus. It is a flowchart which shows the synchronous operation | movement of a sensor apparatus. It is a conceptual diagram which shows the example of installation of the sensor system in a modification (1). It is a conceptual diagram which shows the example of installation of the sensor system in a modification (2).

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

[1. Overview of sensor system]
FIG. 1 is a block diagram showing a sensor system 1 according to this embodiment. The sensor system 1 is a so-called structural health monitoring system that diagnoses the structural performance of a plurality of structures 101. The sensor system 1 includes one or more sensor devices 2, one or more collection devices 3, a data processing device 4, a diagnostic server 5, a rain gauge 6, an anemometer 7 and a thermometer 8. Prepare. The diagnosis server 5 may be integrated with the data processing device 4. Similarly, the rain gauge 6, the wind direction anemometer 7 and the thermometer 8 may be provided integrally with the sensor device 2.

[2. Structure]
The plurality of structures 101 are, for example, made of a plurality of materials, members, and the like and are constructed with a structure in which the weight is supported by a foundation or the like. In the present embodiment, the structures 101 are buildings as an example. A building is a building which is used for the purpose of a building, that is, a residence, an office, a store, a factory, a warehouse, and the like, and has a roof and a peripheral wall. The structure 101 is provided facing the road 102, for example.

[3. Sensor device]
The one or more sensor devices 2 measure a physical quantity of the structure 101 as an object, for example, acceleration when the structure vibrates due to an earthquake or the like, an inclination of the structure, and the like. Each sensor device 2 may be installed at least one, preferably a plurality, for each of the plurality of structures 101. When a plurality of sensor devices 2 are installed for one structure 101, these sensor devices 2 are preferably provided, for example, on a lower floor (for example, the first floor) and a higher floor (for example, the uppermost floor). Is also provided on one or more middle floors and / or on the ground or underground.

  Each sensor device 2 includes, for example, a memory 20, a timer unit 22, a sensor unit 24, a control unit 25, and a communication unit 26, and preferably further includes a clock output unit 21, a temperature sensor 23, and a power supply 28. ing.

  The clock output unit 21 outputs a clock signal to each unit in the apparatus. In the present embodiment, the clock output unit 21 includes a low frequency clock output unit 211 and a high frequency clock output unit 212. The low frequency clock output unit 211 is always driven and outputs the first clock. The high frequency clock output unit 212 outputs a second clock having a frequency higher than that of the first clock and stops during a power saving period described later. For example, the frequency of the first clock is several tens of kHz, and the frequency of the second clock is several MHz to several tens of MHz. The clock output unit 21 may output the first clock to the time measuring unit 22, and may output the second clock to an AD converter 241, a control unit 25, and a communication unit 26 described later in the sensor unit 24.

  The high-frequency clock output unit 212 that outputs the second clock includes a voltage-controlled oscillator (VCO) that can control the oscillation frequency by a voltage, and a DA converter that applies a control voltage to the voltage-controlled oscillator. May be. The control voltage output from the DA converter to the voltage controlled oscillator may be set by the control unit 25.

  The time measuring unit 22 measures time. For example, the timer unit 22 is a circuit having a clock function, and may hold time information therein. As will be described later, the time measuring unit 22 of each sensor device 2 may be synchronized with an external reference time by the control unit 25, and thereby the time information may be maintained in a synchronized state. Further, the timer unit 22 may clock the time based on the first clock (low frequency clock) output from the clock output unit 21. Counting the time based on the clock may be counting while counting up at the timing of the clock. The timer unit 22 may output the current time to the control unit 25 or the like.

  The memory 20 stores programs and data for realizing various functions of the sensor device 2. For example, the memory 20 may store physical quantity data measured by the sensor unit 24.

  The sensor unit 24 measures the above-described physical quantity (for example, acceleration) of the structure 101. The sensor unit 24 may supply the measured physical quantity data to the control unit 25. The sensor unit 24 may include a sensor circuit 240, an AD converter 241, and a determination circuit 242.

  The sensor circuit 240 outputs an analog value of the physical quantity of the structure 101 to the AD converter 241. For example, the sensor circuit 240 may include a sensor that can detect the acceleration when the structure vibrates due to an earthquake or the like, and the inclination of the structure. As an example, the sensor may be a MEMS device integrated on a single silicon substrate, glass substrate, organic material, or the like, and more specifically, a capacitive sensor.

  The sensor circuit 240 may be driven by being supplied with power during the observation period for observing the physical quantity of the structure 101, and may be driven by being supplied with power only at the measurement timing outside the observation period. The measurement timing is a monitoring measurement timing for monitoring whether or not a sudden event occurs, and may be set intermittently outside the observation period, for example. At the measurement timing, the control unit 25 and the like may be in a power saving state. The sensor circuit 240 may operate based on the first clock (low frequency clock) output from the clock output unit 21.

  The AD converter 241 converts the analog value of the physical quantity output from the sensor circuit 240 into a digital value and supplies the digital value to the control unit 25. The AD converter 241 may be driven by power supplied during the observation period. The AD converter 241 may operate based on the second clock (high frequency clock) output from the clock output unit 21. Details of the operation timing of the AD converter 241 will be described later.

  The determination circuit 242 is a circuit that monitors the occurrence of sudden events (for example, disasters such as earthquakes and typhoons, and traffic accidents). The determination circuit 242 is driven by being supplied with power at the measurement timing, and is output from the sensor circuit 240. It is determined whether the analog value of the physical quantity is within the reference range.

  Here, the reference range for the analog value of the physical quantity may be arbitrarily set according to the type of the physical quantity, the measurement accuracy of the sensor circuit 240, and the like. The reference range may be a range indicating a change rate with respect to the physical quantity measured immediately before.

  When the determination circuit 242 determines that the analog value of the physical quantity is out of the reference range, the determination circuit 242 outputs an energization instruction signal to the microprocessor 250 in the control unit 25 to change the control unit 25 from the power saving state to the normal state. You may make a transition. The determination circuit 242 may operate based on the first clock (low frequency clock) output from the clock output unit 21. Details of the operation timing of the determination circuit 242 will be described later.

  Here, the sensor unit 24 can transition between a normal state and a power saving state. The normal state is a state where the sensor circuit 240 and the AD converter 241 are turned on. Further, the determination circuit 242 may be turned on. The sensor unit 24 in the normal state can measure the analog value of the physical quantity of the structure 101 by the sensor circuit 240, convert the analog value to a digital value by the AD converter 241, and output the digital value.

  The power saving state is a state in which the sensor circuit 240 and the determination circuit 242 are turned on. The sensor unit 24 in the power saving state measures the analog value of the physical quantity of the structure by the sensor circuit 240 and can determine whether the analog value is within the reference range by the determination circuit 242.

  The temperature sensor 23 is a sensor that measures temperature in order to calculate the correction value of the clock output unit 21. For example, the temperature sensor 23 may measure the temperature inside the sensor device 2, preferably the temperature of the clock output unit 21. The temperature sensor may output the measurement result to the control unit 25.

  The control unit 25 controls each unit of the sensor device 2 such as the sensor unit 24 and the time measuring unit 22. As an example, the control unit 25 may include a microprocessor 250. The control unit 25 may include a microcontroller instead of the microprocessor 250.

  The control unit 25 may operate based on the second clock (high frequency clock) output from the clock output unit 21. More specifically, the microprocessor 250 of the control unit 25 may operate based on the second clock (high frequency clock). Details of the operation of the control unit 25 will be described later.

  The communication unit 26 communicates with an external device. As an example, the communication unit 26 in the present embodiment wirelessly communicates with a corresponding one of the plurality of collection devices 3. For example, the communication unit 26 may receive physical quantity data in the memory 20 from the control unit 25 and transmit it to the collection device 3. The communication unit 26 may receive time information from the collection device 3 and supply the time information to the control unit 25. The communication unit 26 may operate based on the second clock (high frequency clock) output from the clock output unit 21.

  The communication unit 26 described above may communicate with the collection device 3 by wireless communication according to an arbitrary communication standard, and preferably communicates by short-range wireless communication. As the short-range wireless communication, Bluetooth (registered trademark) class 1 (communication distance of about 100 m), class 2 (communication distance of about 10 m) or class 3 (communication distance of about 1 m), 2.5 GHz using the 2.5 GHz band. Wi-fi using a band or 5 GHz band (communication distance of several tens to several hundreds of meters), infrared communication using an infrared wavelength band (communication distance of less than about 1 m), or 27 MHz band, 150 MHz band, 400 MHz band, 900 MHz Simple wireless communication using a band, a 920 MHz band, a 950 MHz band, or a 50 GHz band can be used. In the present embodiment, the communication unit 26 communicates with the collection device 3 by simple wireless communication in the 920 MHz band. However, the communication unit 26 may communicate with the collection device 3 by wired communication.

  The power source 28 generates electric power using environmental energy, accumulates electric power, and supplies it to each part of the sensor device 2. As environmental energy, for example, light, wind force, and / or constant vibration of a structure can be used. For example, the power source 28 includes a solar panel 280 that generates power by receiving natural light such as sunlight and / or light such as illumination light from a lighting device. The solar panel 280 may be provided integrally with the housing of the sensor device 2 or may be provided separately. The orientation may be changed with respect to the housing, and the housing may be installed at a position and orientation where the amount of received light per day is the largest. As an example, the solar panel 280 may be directed to the structure 101 itself or an artificial lamp when the structure 101 has an artificial light. Moreover, the solar panel 280 may be installed on the outer surface (for example, a roof top surface and an outer wall surface) of the structure 101, or may be installed on the inner surface (for example, an inner wall surface).

[4. Collection device]
The one or more collection devices 3 collect the physical quantities of the structure 101 from the sensor device 2. Each collection device 3 may be provided in association with a structure group 1000 including at least one structure 101. For example, the plurality of collection devices 3 are provided in association with the structure group 1000 including only one structure 101, that is, provided in a one-to-one correspondence with each of the plurality of structures 101. It has been. However, the plurality of collecting devices 3 may be provided in association with the structure group 1000 including the two structures 101 sandwiching the road 102.

  Each collection device 3 may be installed within 100 m, preferably within 50 m from each structure 101 included in the corresponding structure group 1000. In a normal case, the minimum distance between the structure groups 1000 is the distance between each sensor device 2 installed in each structure group 1000 and the collection device 3 corresponding to the structure group 1000. It may be longer than the maximum distance. That is, the minimum distance between the structure groups 1000 may be longer than the maximum wireless transmission distance at which each sensor device 2 installed in each structure group 1000 wirelessly transmits physical quantity data. Thereby, when the collection device 3 is shared between the distant structure groups 1000, it is possible to prevent the wireless communication distance of the sensor device 2 from becoming long and the power consumption of the sensor device 2 from increasing. Further, it is possible to avoid congestion between wireless transmission from the sensor device 2 installed in one structure group 1000 and wireless transmission from the sensor device 2 installed in another structure group 1000.

  Each collection device 3 wirelessly collects physical quantity data wirelessly transmitted from each sensor device 2 installed in each structure 101 included in the target structure group 1000, and includes a memory 30, A clock output unit 31, a time measurement unit 32, a time reception unit 33, a wireless communication unit 34, a control unit 35, and a data transmission unit 36 are provided.

  The memory 30 stores programs and data for realizing various functions of the collection device 3. For example, the memory 30 stores physical quantity data collected from the plurality of sensor devices 2.

  The clock output unit 31 outputs a clock signal to each unit in the apparatus. Further, the timer unit 32 measures the time based on the clock signal. For example, the time measuring unit 32 is a circuit having a clock function, and may hold time information therein. Further, the time measuring unit 32 may output the current time to the control unit 35. In addition, the time information in the time measuring unit 32 is synchronized with an external reference time by the control unit 35 as described later.

  The time receiving unit 33 receives time information from an external device and supplies the time information to the control unit 35. As an example, the time receiving unit 33 may receive time information included in the radio wave by receiving a GPS radio wave from a GPS (Global Positioning System).

  The wireless communication unit 34 wirelessly communicates with the communication units 26 of the plurality of sensor devices 2. For example, the wireless communication unit 34 collects physical quantity data from the plurality of sensor devices 2 and supplies the collected physical quantity data to the control unit 35. In addition, the wireless communication unit 34 transmits time information in the time measuring unit 32 to the plurality of sensor devices 2.

  The control unit 35 includes a microcontroller or a microprocessor as an example, and controls each unit. For example, the control unit 35 synchronizes the time measuring unit 32 with an external reference time. As an example, the control unit 35 causes the time receiving unit 33 to receive GPS radio waves, receives time information included in the radio waves from the time receiving unit 33, and supplies the time information to the time measuring unit 32. The time information in 32 is matched.

  In addition, the control unit 35 synchronizes the time of each sensor device 2 installed in each structure 101 included in the structure group 1000 corresponding to the collection device 3. For example, the control unit 35 reads the time information in the time measuring unit 32 and transmits the time information to each sensor device 2 via the wireless communication unit 34, thereby synchronizing the time measuring unit 22 of each sensor device 2 with the time measuring unit 32. . The details of the synchronization of the timer unit 22 will be described later.

  Further, the control unit 35 stores the physical quantity data received by the wireless communication unit 34 in the memory 30 in association with an identifier for identifying the sensor device 2 that is the transmission source. Then, the control unit 35 reads the physical quantity data from the memory 30 and supplies it to the data transmission unit 36 together with the identifier.

  The data transmission unit 36 transmits the physical quantity data supplied from the control unit 35 to the data processing device 4 connected to the collection device 3 by wire or wirelessly.

[5. Data processing apparatus and diagnostic server]
The data processing device 4 is connected to a plurality of collecting devices 3. The data processing device 4 receives physical quantity data collected by the plurality of collection devices 3 from the plurality of collection devices 3 and performs various processes on the physical quantity data of the structure 101. For example, the data processing device 4 distributes the received physical quantity data for each structure 101 and for each sensor device 2 and provides the data to the diagnosis server 5.

  The diagnosis server 5 diagnoses the structural performance of the structure 101 by analyzing the physical quantity data from the data processing device 4 for each structure 101. For example, the diagnosis server 5 may periodically analyze acceleration data measured by the sensor device 2 to calculate the resonance frequency of the structure 101, and diagnose the structural performance of the structure from its secular change. Further, the diagnosis server 5 may analyze the acceleration data to calculate the displacement of the hierarchy in which each of the plurality of sensor devices 2 is provided, and diagnose the structural performance of the structure from the secular change. More specifically, the diagnosis server 5 determines the maximum acceleration, the maximum interlayer deformation angle (the maximum value obtained by dividing the horizontal displacement of the structure at the time of the earthquake by the floor height, for example, the twice integrated value of the acceleration measurement value), The structural performance (decrease in rigidity) may be diagnosed from the calculation results and / or changes in the natural frequency, mode (amplitude shape when vibrating at the natural frequency), and the like. Further, the diagnosis server 5 may display the diagnosis result to urge the maintenance company to perform maintenance, or may notify the user of the structure 101 of the danger. The diagnosis server 5 may be integrated with the data processing device 4.

  The data processing device 4 and the diagnostic server 5 may manage the data analysis result as a history, and may also manage the setting of the sensor unit 24 and the history thereof. Furthermore, the data processing device 4 and the diagnostic server 5 may also hold the measurement data of the rain gauge 6, the wind direction anemometer 7 and the thermometer 8 connected via the network together with these data.

[6. Rain gauge, wind direction anemometer, thermometer]
The rain gauge 6 measures rainfall in an area including the structure group 1000. Moreover, the wind direction anemometer 7 measures the wind direction and the wind speed in the area where the structure group 1000 is included. The thermometer 8 measures the air temperature in the area where the structure group 1000 is included. The rain gauge 6, wind direction anemometer 7, and thermometer 8 may always perform measurement or may be performed in synchronization with the observation period of the sensor device 2. Further, the rain gauge 6, the wind direction anemometer 7 and the thermometer 8 may transmit the measurement data and time information at the time of measurement to the diagnosis server 5 in association with each other. Note that the rain gauge 6, the wind direction anemometer 7, and the thermometer 8 may be provided integrally with the sensor device 2.

[7. Operation mode of sensor device]
FIG. 2 is a timing chart showing operation modes of the sensor device 2 according to the present embodiment.

  As shown in this figure, the sensor device 2 is operable in an observation mode, a synchronization mode, and a power saving mode. The sensor device 2 may also be operable in a transmission mode.

  Here, the observation mode is a mode for measuring a physical quantity of the structure 101. In the observation mode, at least the sensor unit 24, the clock output unit 21, the time measuring unit 22, the control unit 25, and the memory 20 may be operable in a normal state.

  The observation mode may be continued within a preset observation period. The observation period may be an intermittent period of a predetermined time interval, such as 3 minutes every hour.

  The transmission mode is a mode in which the measured physical quantity is transmitted to an external device (for example, the collection device 3). In the transmission mode, at least the control unit 25, the clock output unit 21, the time measuring unit 22, the memory 20, and the communication unit 26 may be operable in a normal state.

  The transmission mode may continue within a preset transmission period. The transmission period is a period in which the physical quantity data measured by the sensor device 2 is transmitted to the collection device 3, and may be a period after the observation period, for example. As an example, the transmission period may be set after each observation period, or may be set after a plurality of observation periods.

  The synchronization mode is a mode in which time information is received from an external device (for example, the collection device 3) and the timer unit 22 is synchronized. In the synchronous mode, at least the control unit 25, the clock output unit 21, the time measuring unit 22, the temperature sensor 23, and the communication unit 26 may be operable in a normal state.

  The synchronization mode may be continued within a preset time synchronization period. The time synchronization period may be a period for each predetermined time interval, preferably a period that does not overlap with the observation period, and more preferably a period immediately before the observation period. Thereby, in each of the plurality of observation periods following each of the plurality of time synchronization periods, the physical quantity of the structure 101 is measured by the plurality of sensor units 24, so that the behavior of each part of the structure 101 is accurately measured. . Therefore, it is possible to improve the reliability of diagnosis by the diagnosis server 5 regarding the earthquake resistance, aging deterioration, etc. of the structure 101. For example, when the sampling frequency of the measurement data is 200 Hz, the time synchronization error between the sensor devices 2 is preferably within ± 1 ms.

  The power saving mode may be a mode for monitoring the occurrence of sudden events (for example, disasters such as earthquakes and typhoons, and traffic accidents) while suppressing power consumption.

  In the power saving mode, the high frequency clock output unit 212, the memory 20, and the communication unit 26 in the clock output unit 21 may be in a power saving state (for example, a power supply OFF state). By putting the high-frequency clock output unit 212 with high power consumption into a power saving state in the power saving mode, power consumption can be suppressed.

  In the power saving mode, the sensor unit 24 may be in the power saving state because the AD converter 241 is in the power off state, and the control unit 25 is in the power saving state because the microprocessor 250 is in the power off state. It may be.

  On the other hand, the sensor circuit 240 and the determination circuit 242 in the sensor unit 24, the low-frequency clock output unit 211 in the clock output unit 21, the time measuring unit 22, and the control unit 25 are monitored in the power saving mode in order to monitor the occurrence of the sudden event. May be in an operable power state. As an example, the control unit 25 may be in a power saving state with low power consumption. For example, the control unit 25 may be in a state where the operating frequency is lowered and / or in a state where an internal storage device such as a cache memory is stopped after flushing. The determination circuit 242 and the sensor circuit 240 may be intermittently driven at the measurement timing, and determine whether the analog value of the physical quantity output from the sensor circuit 240 is within the reference range. Note that when the occurrence of a sudden event is detected in the power saving mode, the sensor device 2 may transition to the observation mode.

  The power saving mode may be continued within a preset power saving period. The power saving period may be a period different from the above-described observation period, transmission period, and time synchronization period.

[8. Operation of sensor system]
Next, the operation of the sensor system 1 will be described. FIG. 3 is a flowchart showing the operation of the sensor system 1. In the following processing, it will be described that the sensor device 2 is in a stopped state before the start of the observation period.

  First, in S100, the control unit 25 of the sensor device 2 refers to the time information output from the time measuring unit 22, and determines whether or not the observation period starts. As an example, the microprocessor 250 in the control unit 25 in the power saving state determines that the observation period starts when the time indicated by the time measuring unit 22 is on the hour, that is, 0 minutes and 0 seconds every hour.

  If it is determined that the observation period starts in S100 (S100; Yes), the control unit 25 changes the sensor unit 2 from the power saving mode to the observation mode in the observation period with the power of the sensor unit 24 being measurable. (S101). For example, the microprocessor 250 of the control unit 25 causes the control unit 25 to transition from the power saving state to the normal state, and the control unit 25 in the normal state sets the AD converter 241 and the communication unit 26 to the power saving state (for example, power OFF) State) to a normal state (for example, a power ON state). Further, the control unit 25 may put the memory 20 and the high-frequency clock output unit 212 in a normal state.

  Next, the control unit 25 causes the sensor unit 24 to measure the physical quantity of the structure 101 (S102). For example, the sensor circuit 240 of the sensor unit 24 measures an analog value of a physical quantity, and the AD converter 241 converts the analog value into a digital value and supplies it to the control unit 25. The sampling frequency of measurement data by the sensor unit 24 may be 200 Hz, for example. The measurement of the physical quantity by the sensor unit 24 may be continued for the observation period, for example, for 3 minutes.

  Thus, by measuring the physical quantity during the intermittent observation period, the power consumption of the power supply 28 is reduced. The sensor unit 24 may supply the physical quantity data to the control unit 25 after performing modulation, demodulation, zero point adjustment, and the like on the analog physical quantity data.

  Next, the control unit 25 records physical quantity data in the memory 20 (S104). For example, the control unit 25 may store the physical quantity data received from the sensor unit 24 in the memory 20 in association with the time information received from the time measuring unit 22. This S104 may be performed in parallel with the above-described S102. Through the processes in S102 and S104, the physical quantity measured in each intermittent observation period is recorded in the memory 20.

    Next, the control unit 25 determines whether or not the amount of power stored in the power supply 28 is greater than or equal to a reference amount (S105). The reference amount for the storage amount is, for example, the storage amount necessary for the communication unit 26 to transmit the physical amount data in the memory 20, the storage amount necessary for synchronizing the time measuring unit 22, and the sensor unit 24 for the physical amount. It may be set based on at least one of the amount of power storage required for measuring data. As an example, this power storage amount may be a power storage amount required when the sensor device 2 repeatedly executes the processes of S100 to S105 and the processes of S106 to S113 and S204 described later for one day.

  When the charged amount is less than the reference amount (S105; No), the control unit 25 shifts the processing to S109 described later without transmitting physical quantity data in S106 and S108 described later. When the amount of stored electricity is equal to or greater than the reference amount (S105; Yes), the sensor device 2 establishes communication with the collection device 3 in the transmission period with the communication unit 26 in a communicable power state (S106). , S120).

  For example, the control unit 25 of the sensor device 2 may cause the sensor device 2 to transition to the transmission mode. As an example, the control unit 25 may cause the communication unit 26 to transition from the power saving state to the normal state. Further, the control unit 25 may cause the sensor unit 24 to transition to the power saving state. After the transition to the transmission mode, the control unit 25 refers to the time information output from the time measuring unit 22, and communicates with the communication unit 26 and the collection device 3 at a timing assigned in advance from the collection device 3 to the sensor device 2. Communication may be established with the.

  Next, the control unit 25 causes the communication unit 26 to transmit the physical quantity of the structure 101 to the collection device 3 during the transmission period (S108). For example, the control unit 25 reads a combination of physical quantity data and time information from the memory 20 and supplies the combination to the communication unit 26 together with the identifier of the sensor device 2. Then, the communication unit 26 transmits the supplied physical quantity data and the like to the collection device 3.

  As a result of S105 to S108 described above, when the storage amount of the power supply 28 is less than the reference amount (S105; No), the physical amount data is not transmitted, and when the storage amount is equal to or more than the reference amount (S105; Yes), the physical amount Data transmission is performed. As a result, at least a part of the physical quantity measured at night by the sensor unit 24 is transmitted by the communication unit 26 after the stored amount of power generated by the solar panel 280 exceeds the reference amount. Therefore, it is possible to prevent the physical quantity from being unable to be measured due to excessive consumption of the power supply 28 during night communication. The nighttime may be from sunset to sunrise, or may be a time zone in which the power generation amount by the solar panel 280 is equal to or less than the reference power generation amount.

  Here, the transmission period during which the processes of S106 and S108 described above are performed may be different for each sensor device 2. For example, for a plurality of sensor devices 2 installed in the structure group 1000 associated with one collection device 3, the timing after the preset interval from the observation period is assigned in advance as the start timing of each transmission period. May be. The interval may be set based on the identification information of the sensor device.

  For example, when three sensor devices 2 with identifiers (1) to (3) correspond to one collection device 3, one minute from the observation period (= identifier number) with respect to the sensor device 2 with identifier (1) The timing after the interval of (1) × 1 minute) may be assigned as the start timing of the transmission period. Further, a timing after an interval of 2 minutes (= identifier number (2) × 1 minute) from the observation period may be assigned to the sensor device 2 of the identifier (2) as the start timing of the transmission period. Further, a timing after an interval of 3 minutes (= identifier number (3) × 1 minute) from the observation period may be assigned to the sensor device 2 of the identifier (3) as the start timing of the transmission period. The length of the interval is not limited to 1 minute, and is set longer than the data transmission time from each sensor device 2 to the collection device 3.

  Accordingly, each of the plurality of sensor devices 2 transmits the measured physical quantity data to the collection device 3 in each transmission period after an interval preset for the sensor device 2 from the observation period. Therefore, the competition by each sensor apparatus 2 is avoided. The processing after receiving the physical quantity data by the collection device 3 will be described later.

  Next, after determining that the current time is the power saving period, the control unit 25 sets the communication unit 26 and the sensor unit 24 to the power saving state, and shifts the sensor device 2 to the power saving mode (S109). The process is transferred to. Furthermore, the control unit 25 may cause the memory 20, the high frequency clock output unit 212, and the control unit 25 itself to transition to the power saving state.

  On the other hand, if it is determined in S100 that the observation period does not start (S100; No), that is, if the current time is a power saving period, an unexpected event (for example, a disaster such as an earthquake or a typhoon, or a traffic accident) In order to monitor the occurrence of occurrence, the sensor circuit 240 of the sensor unit 24 measures the physical quantity at the measurement timing (S110). For example, the microprocessor 250 of the control unit 25 may be driven by turning on the sensor circuit 240 and the determination circuit 242 at the measurement timing. The sensor circuit 240 may continuously measure the physical quantity within one duration (for example, 10 ms), or may measure the physical quantity once instantaneously.

  Next, the determination circuit 242 of the sensor unit 24 determines whether or not a sudden event has occurred (S112). For example, the determination circuit 242 may determine that an unexpected event has occurred when the analog value of the physical quantity measured in S110 is outside the reference range.

  When it is determined in S112 that no sudden event occurs (S112; No), the sensor device 2 returns the process to S100 described above. Thereby, unless the observation period starts (S100; No), the process of S110 is repeatedly performed. In this case, the process of S110 may be performed intermittently at every reference interval (for example, every 200 ms).

  When it is determined in S112 that a sudden event has occurred (S112; Yes), the sensor device 2 transitions to the observation mode (S113). For example, the determination circuit 242 outputs an energization instruction signal to the control unit 25, causes the control unit 25 to transition from the power saving state to the normal state, and the normal state control unit 25 performs the sensor device in the same manner as in S101 described above. 2 may be changed to the observation mode. And if the process of S113 is complete | finished, the sensor apparatus 2 will transfer a process to above-mentioned S102.

  Thus, even during the intermittent observation period, the physical quantity is measured by S110 at a plurality of intermittent measurement timings. When a physical quantity outside the reference range is measured at one of the plurality of measurement timings, an additional observation period is started in accordance with S102 described above. In addition, the sensor apparatus 2 may repeat the process of S100, without performing the process of S110 and S112, when it determines with the observation period not starting by the process of S100 mentioned above (S100; No).

  Here, when physical quantity data is transmitted from each sensor device 2 in the transmission period by the process of S108 described above, the collection apparatus 3 receives and collects these physical quantity data (S122). For example, the control unit 35 of the collection device 3 may store the physical quantity data received by the wireless communication unit 34 in the memory 30. Further, when the physical quantity data, time information, and the identifier of the sensor device 2 are transmitted in association with each other from the sensor device 2, the control unit 35 may store these combinations in the memory 30.

  Next, the collection device 3 transmits physical quantity data collected from the plurality of sensor devices 2 to the data processing device 4 (S124). For example, the control unit 35 of the collection device 3 reads the combination of the physical quantity, the time information, and the identifier of the sensor device 2 from the memory 30 and supplies it to the data transmission unit 36. Then, the data transmission unit 36 transmits the supplied physical quantity data and the like to the data processing device 4.

  Next, the data processing device 4 receives physical quantity data from the plurality of collection devices 3 (S130). For example, the data processing device 4 may store physical quantity data received from the collection device 3 in an internal storage device. When physical quantity data, time information, and the identifier of the sensor device 2 are transmitted in association with each other from the collection device 3, the data processing device 4 may store these combinations.

  Then, the data processing device 4 performs data processing on the received physical quantity data (S132). For example, the data processing device 4 distributes the received physical quantity data for each structure 101 and for each sensor device 2 and provides the data to the diagnosis server 5. However, the data processing device 4 may diagnose the structural performance of the structure 101 by analyzing the physical quantity data for each sensor device 2.

  According to the sensor system 1 described above, since the control unit 25 places the communication unit 26 and the sensor unit 24 in the power saving state during the power saving period, the power consumption is remarkably increased compared to the case where the control unit 25 is always in the normal state. Can be prevented. Further, since the communication unit 26 is in a power state in which communication is possible in the transmission period after the observation period, power consumption in the observation period can be suppressed.

[8-1. Synchronous operation of sensor device]
In the sensor system 1 according to the present embodiment, the sensor device 2 is synchronized not only periodically but also when returning from power loss.
FIG. 4 is a flowchart showing a periodic synchronization operation of the sensor device 2 according to the present embodiment.

  As shown in this figure, in order to synchronize each timer unit 22 of the plurality of sensor devices 2, first, the control unit 35 of the collection device 3 refers to the timer unit 32 and the time synchronization period of the sensor device 2 starts. It is determined whether or not to perform (S200). When it determines with a time synchronous period not starting in this step S200 (S200; No), the control part 35 returns to the process of S200.

  If it is determined in step S200 that the time synchronization period starts (S200; Yes), the control unit 35 reads the time information held by the time measuring unit 32 during the time synchronization period, and the plurality of sensor devices are read from the wireless communication unit 34. 2 is transmitted (S202). For example, the wireless communication unit 34 may transmit time information uniformly to the plurality of sensor devices 2, or may establish communication with each sensor device 2 and transmit time information individually. Further, when it is determined that the time synchronization period starts, the control unit 35 causes the time reception unit 33 to receive the GPS radio wave, matches the time of the time measurement unit 32 with the time information included therein, and then the time measurement unit. You may make 32 time information transmit to the sensor apparatus 2. FIG.

  Next, in the time synchronization period, the control unit 25 of the sensor device 2 changes the sensor device 2 to the synchronous mode, sets the clock output unit 21, the time measuring unit 22, and the communication unit 26 to the normal state, and receives them by the communication unit 26. The timer unit 22 is synchronized with the time information (S204). For example, the control unit 25 may receive time information from the collection device 3 with the communication unit 26 in a communicable power state, and adjust the time of the time measuring unit 22 based on the time information. As an example, the control unit 25 may update the time information in the time measuring unit 22 with the time information received from the collection device 3 as the current time information. In addition, the control unit 25 calculates in advance a time lag required from the time information read by the collection device 3 to the time information updated by the sensor device 2, and the time lag received from the collection device 3 is added to the time lag. The time information in the time measuring unit 22 may be updated with the time information of the time obtained by adding the time as the current time information.

  FIG. 5 is a flowchart showing a synchronization operation when the sensor device 2 according to the present embodiment recovers from power loss. As shown in this figure, when the power supply 28 of the sensor device 2 loses power and then returns due to power storage, the control unit 25 requests the collection device 3 to return from the communication unit 26 (S201). . At this time, the control unit 25 may cause the communication unit 26 to receive time information from an external device. Thus, an additional time synchronization period is started, and the sensor system 1 performs the above-described processes of S202 and S204. As a result, when the communication unit 26 receives the time information, the time of the time measuring unit 22 is adjusted based on the time information.

  Here, in the time synchronization period, the control unit 25 may set the correction value of the second clock output from the high-frequency clock output unit 212. For example, the control unit 25 may change the temperature sensor from the power saving state to the normal state during the time synchronization period, and set the correction value of the second clock based on the output of the temperature sensor 23. As an example, the memory 20 may store the relationship between the error value of the output frequency of the high-frequency clock output unit 212 measured in advance and the temperature of the high-frequency clock output unit 212 as a lookup table or a function expression. 25 may derive an error value corresponding to the current temperature from this relationship, and correct the clock timing of the high-frequency clock output unit 212 using the error value as a correction value. When the high-frequency clock output unit 212 includes a voltage controlled oscillator (VCO) and a DA converter that outputs a control voltage, the memory 20 has a correction value for the control voltage at each temperature. The control unit 25 may set the correction value for the VCO converter.

  As a result, the frequency fluctuation of the high-frequency clock output unit 212 is preferably within ± 5.56 ppm (= 1 ms / 180 s). In this case, the error that occurs in the observation period of 3 minutes is 1 ms (allowable time error when the measurement data sampling frequency is 200 Hz) or less. Similarly, the control unit 25 may further set a correction value for the first clock output from the low-frequency clock output unit 211.

[9. Example of sensor system installation]
[9-1. Modification (1) of installation example of sensor system]
FIG. 6 is a diagram illustrating an installation example of the sensor system 1 in the modified example (1).

  As shown in this figure, the sensor device 2 of the sensor system 1 according to the modification (1) includes a first structure 105 of the plurality of structures 101 and the opposite side of the road 102 with respect to the first structure 105. And the second structure 106.

  Here, the first structure 105 and the second structure 106 are road-accompanying structures. The road incidental structure is a structure provided on the surface, upper part, or side part of the road 102, such as a signal, a guide display board, lighting equipment, a guardrail, or the like. In the present modification (1), the first structure 105 and the second structure 106 are lighting facilities for the road 102.

  The sensor device 2 is installed on the base portion of the first structure 105 and the second structure 106, the upper part of the support, and the vicinity of the illumination unit. Note that the solar panel 280 of the sensor device 2 installed in the upper part of the support column and in the vicinity of the illumination unit is provided so that the orientation of the solar panel 280 can be changed with respect to the housing of the sensor device 2, so that the amount of received light per day is the largest. In addition to sunlight, the light is directed in a direction capable of receiving illumination light from the illumination unit.

  One of the plurality of collecting devices 3 is provided corresponding to the structure group 1000 including the first structure 105 and the second structure 106, and the first structure 105 and the first structure 105. Communication with the sensor device 2 of the two structures 106 is possible.

[9-2. Modification of installation example of sensor system (2)]
FIG. 7 is a diagram illustrating an installation example of the sensor system 1 in the modification (2).

  As shown in this figure, the sensor device 2 of the sensor system 1 in the present modification (2) includes a first structure 107 provided in a lane in one direction of the road 102 and a first structure 107 in the opposite lane. And the second structure 108 provided at the corresponding position. For example, in the present modification, the first structure 107 and the second structure 108 are road-accompanying structures, and as an example are road guidance display boards.

  One of the plurality of collecting devices 3 is provided corresponding to the first structure 107 and the second structure 108, and the sensors of the first structure 107 and the second structure 108 are provided. Communication with the device 2 is possible.

  In addition, in said embodiment and modification (1), (2), although the structures 101 and 105-108 were demonstrated as a building or a road incidental structure, another structure may be sufficient. Other structures include, for example, airport control towers, airfield lighthouses, highways, stations, railway rails, railway signals, harbor cranes, plants (petrochemicals, iron making), steel bridges, dams, embankments, embankments, It may be a slope, a bank, etc.

  In addition, the sensor system 1 is a structural health monitoring system, and the sensor device 2 is installed on the structure 101 to measure the physical quantity of the structure 101. However, the sensor system 1 uses the structural health monitoring system to improve the structural performance. Instead of diagnosing, it may simply measure acceleration. Moreover, it is another monitoring system, The sensor apparatus 2 is good also as measuring the physical quantity of the other target object different from the structure 101. FIG.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 1 Sensor system, 2 Sensor apparatus, 3 Collecting apparatus, 4 Data processing apparatus, 5 Diagnosis server, 6 Rain gauge, 7 Wind direction anemometer, 8 Thermometer, 20 Memory, 21 Clock output part, 22 Clock part, 23 Temperature sensor, 24 sensor unit, 25 control unit, 26 communication unit, 28 power supply, 30 memory, 31 clock output unit, 32 timing unit, 33 time reception unit, 34 wireless communication unit, 35 control unit, 36 data transmission unit, 101 structure, 102 road, 105 structure, 106 structure, 107 structure, 108 structure, 211 low frequency clock output unit, 212 high frequency clock output unit, 240 sensor circuit, 241 AD converter, 242 determination circuit, 250 microprocessor, 280 Solar panel, 1000 structures

Claims (19)

A sensor unit for measuring a physical quantity of an object;
A communication unit that communicates with an external device;
A timekeeping section that keeps time,
A control unit for controlling the sensor unit and the timing unit;
With
The controller is
In the time synchronization period, time information is received from an external device as a power state in which the communication unit can communicate, and the time of the timekeeping unit is adjusted based on the time information,
In the observation period, let the sensor unit measure the physical quantity of the object as a measurable power state,
A sensor device that places the communication unit and the sensor unit in a power saving state during a power saving period.   2. The sensor according to claim 1, wherein the control unit causes the communication unit to transmit a physical quantity of the object to an external device by using the communication unit as a power state in which the communication unit can communicate in a transmission period after the observation period. apparatus.   The sensor device according to claim 2, wherein the control unit causes the communication unit to transmit a physical quantity of the object in the transmission period after an interval preset for the sensor device from the observation period.   The sensor device according to claim 3, wherein the control unit uses the interval based on identification information of the sensor device. The controller is
In each of a plurality of the time synchronization periods for each predetermined time interval, the time of the time measuring unit is adjusted,
5. The sensor device according to claim 1, wherein a physical quantity of the object is measured by the sensor unit in each of the plurality of observation periods following each of the plurality of time synchronization periods. 6.   The sensor device according to any one of claims 1 to 5, wherein the control unit transitions to a power saving state during the power saving period. The controller is
Between the two observation periods of a predetermined time interval, the physical quantity of the object is measured as a power state in which the sensor unit can be measured at a plurality of intermittent measurement timings,
The sensor device according to any one of claims 1 to 6, wherein the additional observation period is started in response to a physical quantity greater than a reference value being measured at one of the plurality of measurement timings. . The sensor unit is
A sensor circuit that outputs an analog value of a physical quantity of the object;
An AD converter that is supplied with power during the observation period, converts an analog value of the physical quantity into a digital value, and supplies the digital value to the control unit;
A determination circuit for determining whether or not an analog value of the physical quantity is within a reference range by supplying power to the plurality of measurement timings outside the observation period;
The sensor device according to claim 7.   The sensor device according to any one of claims 1 to 8, further comprising a power source that is stored by power generation using environmental energy.   The sensor device according to claim 9, wherein the power source includes a solar panel that can be changed in direction with respect to a housing of the sensor device.   The sensor device according to claim 10, wherein the communication unit transmits at least a part of a physical quantity measured by the sensor unit at night after a storage amount of power generated by the solar panel is equal to or greater than a reference amount. The controller is
The sensor device according to any one of claims 9 to 11, wherein when the power source is restored by power storage after losing power, an external device is notified of the restoration from the communication unit. The controller is
When notifying that the return, the communication unit is in a state in which it can receive time information from the external device,
The sensor device according to claim 12, wherein when the communication unit receives time information, the time of the time measuring unit is adjusted based on the time information. A first clock that is always driven; and a clock output unit that outputs a second clock that has a higher frequency than the first clock and stops during the power saving period;
The timekeeping unit measures time based on the first clock,
The sensor device according to claim 1, wherein the sensor unit and the communication unit operate based on the second clock. A temperature sensor for measuring the temperature;
The sensor device according to claim 14, wherein the control unit sets a correction value of the second clock based on an output of the temperature sensor.   The sensor device according to claim 15, wherein the control unit sets a correction value of the second clock in the time synchronization period. The sensor device according to any one of claims 1 to 16,
A collection device for transmitting time information to the sensor device in the time synchronization period, and collecting a physical quantity of the object from the sensor device in a transmission period after the observation period;
A sensor system comprising:   The sensor system according to claim 17, wherein the sensor device is installed in a structure as the object and measures a physical quantity of the structure. A measuring method in which a sensor device measures a physical quantity of an object,
The sensor device includes:
A sensor unit for measuring a physical quantity of an object;
A communication unit that communicates with an external device;
A timekeeping section that keeps time,
A control unit for controlling the sensor unit and the timing unit;
With
The measurement method is
In the time synchronization period, receiving the time information from an external device as a power state in which the communication unit can communicate, and adjusting the time of the time measuring unit based on the time information;
In the observation period, measuring the physical quantity of the object as a power state that allows the sensor unit to be measured; and
A measurement method comprising: setting the communication unit and the sensor unit to a power saving state during a power saving period.

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