JP2015111091A - Sensor device and abnormality detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable monitoring of an attached state over an attachment member as a whole to fix a structure by a suspension structure.SOLUTION: A sensor device 10 comprises a sensing unit 11, a communication unit 12, a control unit 13, and a power supply unit 14. The sensing unit 11 monitors an attached state of an attachment member 30 to fix a structure to a ceiling in a tunnel by a suspension structure. The communication unit 12 transmits information on the attached state monitored by the sensing unit 11 as attachment information through a radio transmission path. The sensing unit 11 comprises a shaker 110, a first monitoring unit 111, and an output unit 113. The shaker 110 gives a prescribed vibration including frequency components between 1 and 100 kHz to the attachment member 30. The first monitoring unit 111 monitors information on the vibration of the attachment member 30 generated by the vibration given by the shaker 110 as response information.

Description

  The present invention relates to a sensor device that monitors an attachment state of an attachment member that fixes a structure to a ceiling portion in a tunnel with a suspension structure, and an abnormality detection system that detects an abnormality of the attachment member using the sensor device.

  In general, heavy structures such as tunnel ceiling boards, road signs, sound-absorbing boards, jet fans, and ventilation ducts are fixed in a tunnel. This type of structure is often attached to a ceiling portion in a tunnel using an attachment member fixed with an anchor bolt. If the mounting member that fixes the structure with a suspension structure is loosened, pulled out, or corroded, the structure may fall, so the mounting state of this type of mounting member must be periodically inspected. There is.

  For this type of inspection of the mounting member, a method is known in which an operator hits the member with a hammer and the operator judges the sound and impact generated at that time. However, the operation of hitting a large number of mounting members individually with a hammer takes time, and the determination of abnormality is performed by the operator, so that there is a problem that the determination results tend to vary.

  Therefore, Patent Document 1 discloses a technique using a sensor unit including a vibration device that applies vibration to an anchor bolt that is an attachment member for attaching a structure, and a detection device that detects a vibration level from the anchor bolt. Proposed. The sensor unit transmits vibration data detected by the detection device to the control unit. On the other hand, the control unit compares the received vibration data with the vibration data in a normal state to determine whether an abnormality has occurred in the anchor bolt.

  By the way, the configuration described in Patent Document 1 is a configuration in which the vibration generator generates vibration, and the vibration device stops driving based on a command from the vibration command unit. It is estimated that this is a configuration that continuously gives vibrations. Further, acceleration data for each frequency is obtained from an acceleration sensor as a detection device.

Japanese Patent No. 5307948

  In the configuration described in Patent Document 1, when an abnormality occurs in the anchor bolt, the abnormality of the anchor bolt is determined based on the experience side that the acceleration on the low frequency side increases. That is, in the configuration described in Patent Document 1, it is possible to determine the abnormality of the anchor bolt, but it is difficult to monitor the mounting state over the entire mounting member that fixes the structure with the suspension structure.

  It is an object of the present invention to provide a sensor device capable of monitoring the mounting state over the entire mounting member for fixing a structure with a suspension structure, and further, an abnormality detection system using the sensor device. The purpose is to provide.

  The sensor device according to the present invention wirelessly uses, as attachment information, a sensing unit that monitors an attachment state of an attachment member that fixes a structure to a ceiling portion in a tunnel with a suspension structure, and information on the attachment state monitored by the sensing unit. A communication unit that transmits through a transmission path; a control unit that controls operations of the sensing unit and the communication unit; and a power supply unit that supplies power to the sensing unit, the communication unit, and the control unit. A first vibration monitoring device that applies a predetermined vibration including a frequency component of 1 Hz to 100 kHz to the mounting member, and information relating to vibration of the mounting member caused by the vibration applied by the vibration generator as response information. And an output unit that outputs the response information as the attachment information, and the communication unit outputs the attachment information output from the sensing unit. And transmitting at a predetermined timing.

  In this sensor device, the vibrator is a vibrator coupled to the mounting member, and is preferably driven with a short pulse of milliseconds or less.

  In this sensor device, it is preferable that the vibration exciter is an actuator including a hammer, and the hammer is caused to collide with the mounting member in a single shot.

  In this sensor device, it is preferable that the control unit periodically operates the vibrator.

  In this sensor device, it is preferable that the controller operates the vibrator when receiving an instruction from an external signal.

  In this sensor device, the sensor device further includes a second monitoring unit that monitors information related to vibration applied from the vibrator to the mounting member as stimulus information, and the communication unit includes the stimulus information in addition to the response information. It is preferable to transmit it as attachment information.

  In this sensor device, it is preferable that the sensor device further includes a temperature sensor that monitors an ambient temperature of the mounting member as temperature information, and the communication unit transmits the temperature information together with the mounting information.

  In this sensor device, the sensing unit includes a housing base and a housing coupled to the housing base and forming a sealed space for housing the vibrator between the housing base and the excitation base. The container is configured to use a piezoelectric vibrator as a vibration source, and the housing base is configured such that the acoustic impedance thereof is within a range determined with respect to the acoustic impedance of the mounting member. preferable.

  It is preferable that the housing base includes an acoustic insulating portion that suppresses vibration transmission between a region where the piezoelectric vibrator is placed and a region where the housing is coupled.

  It is preferable that the vibrator has a cantilever structure. The vibrator may have a double-supported beam structure. The vibration source is preferably a bimorph type.

  The abnormality detection system according to the present invention includes any one of the sensor devices described above, a receiving device that receives the mounting information from the sensor device, and the receiving device is in a period when the mounting state of the mounting member is normal. The reference information generated based on the mounting information received from the sensor device is compared with the inspection information generated based on the latest mounting information received from the sensor device by the receiving device, and the inspection information is the reference And a determination device that determines an abnormality when the information deviates from a normal range defined for the information.

  According to the configuration of the present invention, a predetermined vibration including a frequency component of 1 Hz to 100 kHz is applied to the mounting member, and information regarding the vibration of the mounting member caused by the applied vibration is monitored as response information. Therefore, by using a wide range of frequency components, there is an advantage that the mounting state can be monitored over the entire mounting member for fixing the structure with the suspension structure.

It is a block diagram which shows embodiment. It is a side view which shows the example of application to the attachment member of embodiment. It is a perspective view which shows the example of application to the tunnel of embodiment. It is sectional drawing which shows the example of 1 structure of the sensing part used for embodiment. It is sectional drawing which shows the other structural example of the sensing part used for embodiment. It is operation | movement explanatory drawing which shows the example of a drive of the sensing part used for embodiment. It is sectional drawing which shows another structural example of the sensing part used for embodiment. It is sectional drawing which shows another structural example of the sensing part used for embodiment. It is sectional drawing which shows another example of a structure of the sensing part used for embodiment.

  As shown in FIG. 1, the sensor device 10 described below includes a sensing unit 11, a communication unit 12, a control unit 13, and a power supply unit 14. The sensing unit 11 monitors the mounting state of the mounting member 30 that fixes the structure 22 to the ceiling 21 in the tunnel 20 with a suspended structure (see FIG. 3). The communication unit 12 transmits information regarding the attachment state monitored by the sensing unit 11 as attachment information through the wireless transmission path. The control unit 13 controls operations of the sensing unit 11 and the communication unit 12. The power supply unit 14 supplies power to the sensing unit 11, the communication unit 12, and the control unit 13.

  The sensing unit 11 includes a vibrator 110, a first monitoring unit 111, and an output unit 113. The vibration exciter 110 gives a predetermined vibration including a frequency component of 1 Hz to 100 kHz to the mounting member 30. The first monitoring unit 111 monitors information related to the vibration of the mounting member 30 caused by the vibration given by the vibrator 110 as response information. The output unit 113 outputs the response information as attachment information. The communication unit 12 transmits the attachment information output from the sensing unit 11 at a predetermined timing.

  The vibrator 110 is a vibrator coupled to the mounting member 30 and is preferably driven with a short pulse of milliseconds or less. Alternatively, the vibration exciter 110 is an actuator provided with a hammer, and it is desirable that the hammer collide with the mounting member 30 once. Regardless of the configuration of the vibration exciter 110, it is possible to apply an impact to the mounting member 30 and take out the impulse response of the mounting member 30 as response information.

  It is desirable for the control unit 13 to periodically operate the vibration exciter 110. Alternatively, the control unit 13 desirably operates the vibration exciter 110 when receiving an instruction from an external signal. If the former configuration is adopted, the inspection of the mounting member 30 can be performed periodically, and if the latter configuration is employed, the inspection of the mounting member 30 can be performed as necessary.

  The sensor device 10 preferably includes a second monitoring unit 112 that monitors information related to vibrations applied from the vibrator 110 to the mounting member 30 as stimulation information. In this case, it is desirable that the communication unit 12 transmits stimulus information as attachment information in addition to response information.

  The sensor device 10 preferably further includes a temperature sensor 15 that monitors the ambient temperature of the mounting member 30 as temperature information. In this case, the communication unit 12 transmits the temperature information together with the attachment information.

  The abnormality detection system described below includes any one of the sensor device 10, the reception device 40, and the determination device 50 described above. The receiving device 40 receives attachment information from the sensor device 10. The determination device 50 includes the reference information generated based on the mounting information received from the sensor device 10 by the receiving device 40 during the period when the mounting state of the mounting member 30 is normal, and the latest information received from the sensor device 10 by the receiving device 40. The inspection information generated based on the attachment information is compared. The determination device 50 determines that the inspection information is abnormal when the inspection information deviates from the normal range defined for the reference information.

  Hereinafter, the configuration of the present embodiment will be described in more detail. In the configuration described below, the structure 22 is an object that is fixed to the ceiling portion 21 of the tunnel 20 in a suspended structure, and corresponds to, for example, a tunnel ceiling plate, a road sign, a sound absorbing plate, a jet fan, and a ventilation duct. To do. In the example of FIG. 3, a ceiling board is shown as the structure 22. As shown in FIG. 2, the attachment member 30 for attaching this type of structure 22 to the ceiling portion 21 is composed of a fixing member 31 fixed to the ceiling portion 21 of the tunnel 20 and an upper end portion coupled to the fixing member 31. A suspension member 32 having a lower end portion coupled to the structure 22 is provided.

  In the mounting member 30 shown in the figure, as shown in FIG. 2, the suspension member 32 includes a connection member 321 including a tie bar (connection bar), a turn buckle, and the like, and a pair of bases respectively coupled to upper and lower ends of the connection member 321. 322. Although only the pedestal 322 coupled to the upper end of the connecting member 321 is shown in FIG. 2, the pedestal 322 coupled to the lower end of the connecting member 321 has a similar structure.

  The pedestal 322 coupled to the upper end of the connecting member 321 is integrally provided with a mounting plate 3221 overlaid on the wall surface 211 of the ceiling portion 21 and a mounting plate 3222 that protrudes downward from the mounting plate 3221. An end of the connecting member 321 is coupled to the mounting plate 3222 using a connecting bolt 323. That is, the connecting member 321 is movable around the connecting bolt 323 with respect to the pedestal 322. A pedestal 322 coupled to the upper end of the connecting member 321 is fixed to the ceiling portion 21 using a fixing member 31 such as an anchor bolt. That is, the upper end of the connecting member 321 is coupled to the base 322 fixed to the ceiling portion 21 of the tunnel 20 by the fixing member 31 by the connecting bolt 323.

  On the other hand, the lower end of the connecting member 321 is connected to a pedestal (not shown) fixed to the structure 22. The base connected to the lower end of the connecting member 321 has the same structure as the base 322 connected to the upper end of the connecting member 321, and the lower end of the connecting member 321 is coupled to the base. In the illustrated example, the pedestal 322 coupled to the upper end of the connecting member 321 and the pedestal coupled to the lower end of the connecting member 321 are provided for each connecting member 321, but a plurality of connecting members 321 are provided on one base. May be combined.

  The fixing member 31 and the suspension member 32 are generally made of metal. As the fixing member 31 and the suspension member 32 continue to be used for a long period of time, deterioration such as corrosion, deformation, and fatigue occurs, and the strength for attaching the structure 22 to the ceiling portion 21 of the tunnel 20 may gradually decrease. There is sex. Therefore, in the present embodiment, the sensor device 10 is provided on the suspension member 32 in order to detect the occurrence or sign of abnormality of the fixing member 31 and the suspension member 32.

  In general, the amount of information that can be obtained increases as the number of places where the sensor device 10 is installed increases. However, the sensor device is provided in at least two places, that is, a position where information about the fixing member 31 is obtained and a position where information about the hanging member 32 is obtained. 10 is preferably provided. In the example shown in FIG. 2, one sensor device 10 is provided on the base 322, and two sensor devices 10 are provided on the connecting member 321. The sensor device 10 provided on the pedestal 322 mainly obtains information on the fixing member 31, and the sensor device 10 provided on the connecting member 321 mainly obtains information on the suspension member 32.

  As shown in FIG. 1, the sensor device 10 includes a sensing unit 11 that monitors the mounting state by applying vibration to the mounting member 30 and monitoring the vibration of the mounting member 30. The sensing unit 11 includes a vibration exciter 110 that applies vibration to the attachment member 30. Specifically, the vibrator 110 uses either a vibrator (piezoelectric vibrator) using a piezoelectric element such as PZT or an actuator provided with a hammer formed of a hard material such as metal. It is done. A configuration for generating a driving force for moving the hammer in the actuator is selected from an electromagnet, a piezoelectric element (electrostrictive element), a magnetostrictive element, and the like. Further, the vibrator 110 may employ a configuration in which the hammer is moved using the rotational force of the motor as the driving force.

  When the vibrator is used, the vibrator is driven by applying a rectangular wave voltage to the vibrator for a short time. That is, a vibration including many frequency components is generated by applying a voltage to the vibrator for a short time. The vibrator is desirably driven with a short pulse (for example, 0.1 ms) of milliseconds or less so that the vibration includes a frequency component of 1 Hz to 100 kHz.

  Moreover, when the vibration exciter 110 is an actuator provided with a hammer, it is desirable to cause the hammer to collide with the mounting member 30 in a single shot. That is, the attachment member 30 is vibrated including a frequency component of 1 Hz to 100 kHz by tapping the attachment member 30 with a hammer.

  These vibrators 110 can give the mounting member 30 vibration including a wide range of frequency components of about 1 Hz to 100 kHz by applying an impact (impulse) to the mounting member 30.

  When the vibration exciter 110 applies vibration to the mounting member 30, this vibration is transmitted to the mounting member 30. Therefore, if the relationship between the vibration applied to the mounting member 30 and the vibration generated in the mounting member 30 due to this vibration is known. Information about the mounting member 30 is obtained. Therefore, the sensing unit 11 includes a first monitoring unit 111 that monitors information related to the vibration of the mounting member 30 caused by the vibration applied by the vibrator 110 as response information.

  A specific configuration example of the sensing unit 11 will be described. As shown in FIG. 4, the sensing unit 11 includes a housing base 61 and a housing 62. The housing base 61 is plate-shaped, and is in close contact with the attachment member 30 in a state where the sensor device 10 is attached to the attachment member 30. The vibrator 110 described below includes a piezoelectric vibrator as a vibration source 1101. In the illustrated example, the vibrator 110 is disposed on the housing base 61 and is fixed to the housing base 61. The vibrator 110 is fixed to the housing base 61 with an adhesive or the like.

  The housing base 61 is formed using a metal selected from the group of iron-based (stainless steel), copper-based alloy, zinc, and the like, and the acoustic impedance thereof is determined with respect to the acoustic impedance of the mounting member 30. It is desirable to be configured to be within the range. The attachment member 30 is made of a metal such as iron (stainless steel).

  If the acoustic impedances of the housing base 61 and the mounting member 30 match, ideally, the energy of vibration generated by the vibrator 110 is transmitted to the mounting member 30 without loss. Even if the acoustic impedances of the housing base 61 and the mounting member 30 do not completely coincide with each other, if the difference in acoustic impedance is small, vibration generated by the vibrator 110 is efficiently transmitted to the mounting member 30. Therefore, the acoustic impedance of the housing base 61 is determined so that the vibration transmission efficiency is equal to or greater than a predetermined value. In short, the housing base 61 is designed so that its acoustic impedance is comparable to the acoustic impedance of the mounting member 30.

  As described above, when the acoustic impedance of the housing base 61 and the acoustic impedance of the mounting member 30 are approximately the same, vibration can be efficiently transmitted to the mounting member 30, leading to a reduction in the size of the vibration source 1101. That is, the sensing unit 11 can be downsized, and thus the sensor device 10 can be downsized. In addition, since the transmission efficiency of vibration from the vibrator 110 to the mounting member 30 is improved, the efficiency of using power supplied to the vibrator 110 is also increased, resulting in a reduction in power consumption.

  A housing 62 is coupled to the housing base 61. The housing 62 is coupled to the housing base 61 and forms a sealed space in which the vibrator 110 is accommodated. The housing 62 is formed in a cap shape covering the housing base 61, and the housing 62 is coupled to the peripheral portion of the housing base 61, thereby forming a space for housing the vibrator 110 between the housing base 61. The housing 62 is preferably made of the same metal as the housing base 61. The housing base 61 and the housing 62 are preferably welded using laser light or the like, but may be joined by brazing or by an adhesive.

  In the space formed between the housing base 61 and the housing 62, it is desirable to house other components of the sensing unit 11, but the other components of the sensing unit 11 are arranged separately from the space. Also good. Further, all the components of the sensor device 10 may be housed in a space formed between the housing base 61 and the housing 62.

  As shown in FIG. 5, the housing base 61 is an acoustic insulating portion that suppresses transmission of vibration from the vibrator 110 between a region where the vibrator 110 is placed and a region where the housing 62 is coupled. 611 may be provided. The illustrated acoustic insulating portion 611 includes a gap between a region where the vibrator 110 is disposed and a region where the housing 62 is coupled. Specifically, a groove 612 is formed on the lower surface (outer surface) of the housing base 61 in FIG. 5, and this groove 612 functions as a gap. The presence of the groove 612 around the region where the vibrator 110 is placed on the housing base 61 reduces the transmission of vibration from the region to the lateral direction of FIG. 5 in the housing base 61.

  The groove 612 may have a shape that continuously surrounds the entire circumference of the vibrator 110 or a shape that surrounds the periphery of the vibrator 110 by a plurality of discontinuously formed grooves 612. The groove may be formed on the upper surface (inner surface) of the housing base 61. Note that the acoustic insulating portion 611 may be formed by using a material different from the other region of the housing base 61 instead of the groove 612. The terms “up”, “down”, and “horizontal” are used in the description of FIG. 5, and are not intended to limit the mounting direction of the sensor device 10.

  As described above, the formation of the acoustic insulating portion 611 makes it difficult for vibration generated in the vibration exciter 110 to be transmitted to the housing 62 and the like, and is transmitted to the mounting member 30 in a concentrated manner. The transmission efficiency of vibration from the mounting member 30 to the mounting member 30 is improved. That is, it leads to further downsizing of the sensing unit 11. Further, since the acoustic insulation portion 611 is provided, the transmission efficiency of vibration from the vibrator 110 to the mounting member 30 is increased, so that the power use efficiency is also increased, resulting in a reduction in power consumption.

  The control unit 13 generates vibration by applying a voltage having a waveform as shown in FIG. 6 to the piezoelectric vibrator that is the vibration source 1101 of the vibrator 110. The illustrated waveform is a single triangular pulse, and at least one of the half-value width Δt and the peak voltage Vp is adjusted. By changing at least one of the half-value width Δt and the peak voltage Vp, the frequency component or amplitude of vibration generated from the vibration source 1101 changes. For example, when the half-value width Δt changes, the main frequency component changes, and when the peak voltage Vp changes, the amplitude mainly changes.

  In the configuration example described above, the vibration source 1101 constituting the vibrator 110 is directly attached to the housing base 61. However, the vibrator 110 is preferably configured in the structure shown in FIGS. FIG. 7 shows a configuration example in which the vibrator 110 has a cantilever structure, and FIG. 8 shows a configuration example in which the vibrator 110 has a cantilever structure. FIG. 9 shows an example in which the vibration source 1101 is a bimorph type.

  In the configuration example shown in FIG. 7, the vibrator 110 includes a support base 1102 fixed to one surface of the housing base 61. One end of a beam 1103 is fixed to the support base 1102, and a weight 1104 is coupled to the other end of the beam 1103. The vibration source 1101 is disposed at an intermediate portion of the beam 1103 and is coupled to the beam 1103. The beam 1103 is formed in a plate shape using a metal plate, and can be bent in the vertical direction in FIG. In addition, the up-down direction only shows the direction in a figure, and is not the objective of determining the direction at the time of use.

  The material forming the support base 1102, the material forming the beam 1103, and the material forming the weight 1104 are selected from the group of iron-based (stainless steel), copper-based alloy, zinc, and the like. The weight 1104 may be integrally formed of the same material as the beam 1103. In this case, the beam 1103 and the weight 1104 can be formed by finely processing semiconductor silicon.

  7 schematically illustrates the width W1 of the inner surface of the housing 62 being about 1 cm, the thickness H1 of the vibration source 1101 being about 1 μm to 1 mm, and the thickness of the weight 1104. H2 is formed to be about 1 to 10 mm. These dimensions are merely examples, and are not intended to limit the dimensions of the sensing unit 11 used in the present embodiment.

  The vibrator 110 may have a double-supported beam structure as shown in FIG. In the configuration example shown in FIG. 7, only one end of the beam 1103 is fixed to the support base 1102, whereas in the configuration example shown in FIG. 8, both ends of the beam 1103 are fixed to the support base 1102. Yes. Further, the weight 1104 is coupled to the lower surface in FIG. Two vibration sources 1101 are provided, and are arranged at a portion between each end of the beam 1103 and the weight 1104. The two vibration sources 1101 are arranged to expand and contract in the same direction. Note that the upper and lower terms are used for the purpose of describing FIG. 8, and are not intended to determine the direction when the sensor device 10 is used.

  In the configuration example shown in FIG. 8, since two vibration sources 1101 are arranged at both ends of the beam 1103, the displacement of the beam 1103 is larger than the configuration including one vibration source 1101 as in the configuration shown in FIG. It becomes possible to take large. Note that the vibration source 1101 and the weight 1104 are desirably arranged with respect to the beam 1103 as shown in the illustrated example, but the vibration source 1101 and the weight 1104 may be reversed with respect to the beam 1103. That is, in the configuration of FIG. 8, the vibration source 1101 may be provided on the lower surface of the beam 1103, and the weight 1104 may be provided on the upper surface of the beam 1103. Since the vibration source 1101 is disposed on one surface of the beam 1103 and the weight 1104 is disposed on the other surface of the beam 1103, when the beam 1103 is bent, the vibration source 1101 and the weight 1104 do not interfere with each other. In other words, the vibration source 1101 and the weight 1104 have a high degree of freedom in dimensions and arrangement. However, when the size and the degree of freedom of arrangement of the vibration source 1101 and the weight 1104 are not a problem, the vibration source 1101 and the weight 1104 may be arranged on the same surface of the beam 1103.

  The configuration example shown in FIG. 9 is a configuration example in which the piezoelectric vibrator serving as the vibration source 1101 is a bimorph type, and the vibration sources 1101 are arranged on both surfaces of the beam 1103 based on the cantilever structure shown in FIG. It has the structure. A voltage is differentially applied to the vibration sources 1101 arranged on each surface of the beam 1103. That is, the two vibration sources 1101 are displaced in directions opposite to each other when a voltage is applied. Accordingly, the displacement of the beam 1103 can be increased. In addition, since the structure is based on a cantilever structure, the length of the beam 1103 can be shortened as compared with the structure of the double-supported structure shown in FIG. 8, resulting in a small size and a large displacement (that is, amplitude). Vibration) can be generated.

  The first monitoring unit 111 may be configured to detect vibration (displacement) of the attachment member 30 such as a piezoelectric element, a differential transformer, an acceleration sensor, an ultrasonic type or an optical type displacement sensor. The 1st monitoring part 111 is arrange | positioned so that the vibration of the attachment member 30 can be detected. Although it is possible to arrange the first monitoring unit 111 side by side with the vibrator 110, it is desirable that the first monitoring unit 111 be separated from the vibrator 110 by an appropriate distance. Further, if the vibrator 110 is a piezoelectric element, the vibrator 110 can also be used as the first monitoring unit 111.

  According to the above-described configuration, since the first monitoring unit 111 monitors the response of the mounting member 30 to the impact (impulse) applied from the vibrator 110, the transfer function of the impulse response can be obtained. That is, if the impulse given to the mounting member 30 by the vibration exciter 110 is known, the transfer function of the impulse response is obtained from the response information monitored by the first monitoring unit 111. Since this transfer function reflects the mounting state of the mounting member 30, if this transfer function is evaluated, mounting information indicating the mounting state of the mounting member 30 is obtained.

  However, the impulse given to the mounting member 30 is not necessarily constant due to a change in time of the vibrator 110 or a change in ambient temperature. Therefore, in this embodiment, the 2nd monitoring part 112 which monitors the information regarding the vibration given to the attachment member 30 from the vibration exciter 110 as stimulus information is provided. When the stimulus information monitored by the second monitoring unit 112 is used, the transfer function can be accurately obtained from the stimulus information and the response information. That is, it becomes possible to obtain the mounting information related to the mounting member 30 with higher accuracy.

  As the second monitoring unit 112, any one of a load sensor that monitors a load acting on the mounting member 30 from the vibrator 110 and a voltage sensor that monitors a voltage value applied to the vibrator 110 is used. The load sensor preferably has a configuration including a piezoelectric element and a sensor amplifier. The voltage sensor preferably has a high input impedance amplifier (or a voltage follower).

  When the second monitoring unit 112 is a load sensor, the second monitoring unit 112 is disposed at a site where a reaction force is generated when the vibration exciter 110 applies an impact to the mounting member 30. The voltage sensor is effective when a piezoelectric element is used for the vibrator 110, and is composed of only an amplifier that monitors the voltage applied to the piezoelectric element with the voltage sensor. The second monitoring unit 112 outputs the waveform output from the load sensor or the voltage sensor as stimulation information related to vibration applied from the vibrator 110 to the mounting member 30.

  The response information output from the first monitoring unit 111 and the stimulus information output from the second monitoring unit 112 are output through the output unit 113 as attachment information that is an output of the sensing unit 11. The attachment information output from the sensing unit 11 is transmitted as a radio signal through the communication unit 12. The communication unit 12 has a function of multi-hop communication that relays a radio signal output from another sensor device 10, and can communicate between distant terminals that do not receive radio waves directly while performing short-range wireless communication. It is possible.

  The sensing unit 11 and the communication unit 12 are controlled by the control unit 13. The control unit 13 includes a device including a processor that operates according to a program as a main hardware element. This type of device is selected from a microcomputer (microcontroller) having a memory integrally with a processor, a processor having a memory separately, a DSP (Digital Signal Processor), an FPGA (Field-Programmable Gate Array), and the like.

  The control part 13 operates the sensing part 11 (vibrator 110) regularly with a fixed period. Or the control part 13 operates the sensing part 11 (vibrator 110), when the instruction | indication by an external signal is received. Such an external signal is given as a wireless signal from another device through the communication unit 12. Moreover, whenever the control part 13 operates the sensing part 11, it delivers the stimulus information and response information output from the sensing part 11 to the communication part 12, and transmits the stimulus information and the response information from the communication part 12 as attachment information. It has a function.

  In short, the control unit 13 determines the timing for operating the sensing unit 11, and determines the timing for transmitting the stimulus information and the response information output from the sensing unit 11 as attachment information from the communication unit 12. Although it is assumed that the stimulus information and the response information are output as analog signals from the sensing unit 11 and converted into digital signals in the control unit 13, the sensing unit 11 may have a function of converting into digital signals. .

  In the sensor device 10, if the communication unit 12 and the control unit 13 are mounted on a single circuit board as a unit, and the sensing unit 11 is also mounted on a single circuit board as a unit, the sensor device 10 Is composed of two units and a power supply unit 14. Thus, by being appropriately unitized, the sensor device 10 can be easily assembled, and the sensing unit 11 on which a mechanical force acts, the communication unit 12 and the control unit 13 including only an electric circuit. Is separated and maintenance becomes easy.

  By the way, in this embodiment, the power supply of the sensor apparatus 10 is supplied from the power supply part 14 provided for every sensor apparatus 10. FIG. That is, the power supply unit 14 is supplied with power from a battery or a small power generator. This type of power generator is preferably an environmental power generator (so-called energy harvester) that converts vibration, heat, light, airflow, and the like generated in the tunnel 20 into electric power. In addition, when supplying electric power from this kind of electric power generating apparatus to the power supply part 14, the control part 13 will transmit attachment information, when required electric power is securable. That is, when this type of power generation device is used as a power source, the sensor device 10 may not be able to operate regularly but may operate irregularly. Moreover, it is desirable that the battery has a capacity capable of operating the sensor device 10 for about 5 to 10 years.

  The power source that supplies power to the sensor device 10 may be provided in units of the attachment member 30. That is, when a plurality of sensor devices 10 are arranged on one mounting member 30, it is possible to provide a power source shared by all the sensor devices 10 provided on one mounting member 30. In this case, it is necessary to connect the power supply lines between the sensor devices 10 arranged on one mounting member 30, but since it is not necessary to connect the power supply lines between the mounting members 30, the construction is relatively easy. It is.

  A large number of sensor devices 10 are arranged inside the tunnel 20, and the mounting information transmitted as radio signals from the individual sensor devices 10 is received by the receiving device 40. That is, the mounting information is transmitted from the sensor device 10 to the receiving device 40 through the wireless communication path. The receiving device 40 extracts the attachment information from the radio signal and inputs the attachment information to the determination device 50.

  The determination device 50 includes a storage unit 51 that stores reference information generated based on the attachment information received from the sensor device 10 by the reception device 40 during a period when the attachment state of the attachment member 30 is known to be normal. In addition, the determination device 50 compares the reference information stored in the storage unit 51 with the inspection information generated based on the latest mounting information received by the receiving device 40, and determines whether the mounting member 30 is in a normal mounting state. A determination unit 52 is provided for determining whether or not.

  The reference information and the inspection information are generated by the generation unit 53 provided in the determination device 50. As the reference information and the examination information, for example, a transfer function obtained by performing FFT (Fast Fourier Transform) on the stimulus information and the response information received by the receiving device 40 from the sensor device 10 is used. When the transfer function is used as the reference information and the examination information, the generation unit 53 obtains a first vector composed of the frequency component of the stimulus information and a second vector composed of the frequency component of the response information, and obtains the first vector. A conversion vector to be converted into the second vector is obtained. The generation unit 53 regards this conversion vector as a transfer function.

  The determination unit 52 obtains a distance (Euclidean distance or Manhattan distance) between the transfer function serving as the inspection information and the transfer function serving as the reference information, and determines whether or not the distance is within a predetermined normal range. When the inspection information deviates from the normal range set based on the reference information, that is, when the distance obtained from the inspection information and the reference information deviates from the normal range, the determination unit 52 determines the attachment member 30. It is determined that an abnormality has occurred.

  In this embodiment, since the determination apparatus 50 evaluates the attachment state of the attachment member 30 using the transfer function calculated | required from irritation | stimulation information and response information, it arises by driving | running | working of a motor vehicle, etc. in the judgment by the judgment part 52 The influence of vibration components (noise) can be reduced. That is, since the determination unit 52 extracts the transfer function that is the relationship between the stimulus information and the response information, the noise that is constantly generated becomes a small value as a component of the transfer function, and the influence of the noise is reduced. The Further, when the determination unit 52 obtains the distance between the reference information and the inspection information, the noise that is regularly generated is removed.

  From the above, in the determination result by the determination device 50, the influence of noise (environmental vibration) caused by traveling of the automobile is reduced, and the attachment state of the attachment member 30 can be accurately determined. Moreover, the reference information obtained from the primary information and the secondary information when the mounting state is normal is stored in the storage unit 51, and the determination unit 52 compares the inspection information with the reference information. Therefore, the attachment state of the attachment member 30 is determined with reference to the normal attachment state, and a reasonable determination can be made regarding the attachment state.

  By the way, although the vibrator 110, the 1st monitoring part 111, and the 2nd monitoring part 112 depend on a specific structure, there exists a possibility that a characteristic may change by the influence of ambient temperature. Therefore, it is desirable to correct the response information according to the ambient temperature of the sensing unit 11. In this case, in order to measure the ambient temperature, it is desirable to provide a temperature sensor 15 as indicated by a broken line in FIG. In the illustrated example, the temperature sensor 15 is provided in the sensing unit 11, but the temperature sensor 15 may be provided independently of the sensing unit 11. The temperature sensor 15 is selected from a thermistor, a thermocouple, and the like.

  The temperature information, which is the ambient temperature measured by the temperature sensor 15, is transmitted through the communication unit 12, and correction using the temperature information is performed when the generation unit 53 of the determination device 50 obtains the reference information and the inspection information. Therefore, the influence of the ambient temperature is reduced with respect to the reference information and the inspection information, and the attachment state of the attachment member 30 can be determined with higher accuracy.

  According to the configuration described above, an impact is applied to the mounting member 30, so that vibration including a broadband frequency component of about 1 Hz to 100 kHz can be applied to the mounting member 30. Therefore, it is possible to evaluate various frequency components with respect to the attachment member 30, and it is possible to accurately determine the attachment state of the attachment member 30.

  In addition, there is a possibility that not only the abnormality of the attachment member 30 but also the presence or absence of abnormality of the structure 22 fixed by the attachment member 30 with a suspension structure may be comprehensively determined. Although the sensor device 10 is attached to the attachment member 30, there is a possibility that the presence or absence of an abnormality can be determined similarly to the attachment member 30 by attaching the sensor device 10 to the structure 22 or the like. Therefore, the sensor device 10 can be used for general purposes.

  In the configuration example described above, since the sensor device 10 includes the power supply unit 14 that supplies power to the sensor device 10 and the communication unit 12 performs wireless communication, there is no need to connect an electric wire to the sensor device 10 and an existing tunnel is provided. Even if it is 20, the sensor device 10 can be easily installed. In addition, the sensor device 10 has a simple configuration only including the sensing unit 11, the communication unit 12, the control unit 13, and the power supply unit 14, and can be configured to be small if a battery is used for the power supply unit 14. Easy to downsize.

  In the configuration example described above, the sensor device 10 transmits two types of information, i.e., stimulus information and response information. When the stimulus information is considered to be substantially constant, only the response information is transmitted from the communication unit 12. You may send it. In this case, the determination device 50 regards the stimulus information as known and determines the attachment state of the attachment member 30 using only the response information. In this case, the reference information and the inspection information may be corrected using the temperature information.

  The above-described embodiment is an example of the present invention, and the present invention is not limited to the above-described embodiment, and other embodiments may be used without departing from the technical idea of the present invention. If so, various changes can be made according to the design and the like.

DESCRIPTION OF SYMBOLS 10 Sensor apparatus 11 Sensing part 12 Communication part 13 Control part 14 Power supply part 15 Temperature sensor 20 Tunnel 21 Ceiling part 22 Structure 30 Attachment member 40 Receiver 50 Determination apparatus 61 Housing base 62 Housing 110 Exciter 111 1st monitoring part 112 2nd monitoring part 113 Output part 611 Sound insulation part 1101 Vibration source

Claims (13)

A sensing unit that monitors the mounting state of a mounting member that fixes the structure to the ceiling in the tunnel with a suspension structure;
A communication unit that transmits information about the mounting state monitored by the sensing unit through a wireless transmission path as mounting information;
A control unit that controls operations of the sensing unit and the communication unit;
A power supply unit that supplies power to the sensing unit, the communication unit, and the control unit;
The sensing unit is
A vibrator for applying a predetermined vibration including a frequency component of 1 Hz to 100 kHz to the mounting member;
A first monitoring unit that monitors information related to the vibration of the mounting member caused by the vibration given by the vibrator as response information;
An output unit that outputs the response information as the attachment information;
The communication unit transmits the attachment information output from the sensing unit at a predetermined timing. The sensor device according to claim 1, wherein the vibrator is a vibrator coupled to the mounting member and is driven with a short pulse of milliseconds or less. The sensor device according to claim 1, wherein the vibration exciter is an actuator including a hammer, and the hammer is caused to collide with the mounting member in a single shot. The sensor device according to any one of claims 1 to 3, wherein the control unit periodically operates the vibrator. The sensor device according to claim 1, wherein the control unit operates the vibrator when receiving an instruction from an external signal. A second monitoring unit for monitoring information related to vibration applied from the vibrator to the mounting member as stimulus information;
The communication unit is
The sensor device according to claim 1, wherein the stimulus information is transmitted as the attachment information in addition to the response information. A temperature sensor that monitors the ambient temperature of the mounting member as temperature information;
The sensor device according to claim 1, wherein the communication unit transmits the temperature information together with the attachment information. The sensing unit is
A housing base;
A housing coupled to the housing base and forming a sealed space for housing the vibrator between the housing base and the housing base;
The vibrator is configured with a piezoelectric vibrator as a vibration source,
The sensor device according to claim 1, wherein the housing base is configured such that an acoustic impedance thereof is within a range determined with respect to an acoustic impedance of the mounting member. The housing base is
The sensor device according to claim 8, further comprising an acoustic insulating portion that suppresses transmission of vibration between a region where the piezoelectric vibrator is placed and a region where the housing is coupled. The sensor device according to claim 8, wherein the vibrator has a cantilever structure. The sensor device according to claim 8, wherein the vibrator has a double-supported beam structure. The sensor device according to claim 10, wherein the vibration source is a bimorph type. The sensor device according to any one of claims 1 to 12,
A receiving device for receiving the mounting information from the sensor device;
Reference information generated based on the mounting information received from the sensor device by the receiving device during a period in which the mounting state of the mounting member is normal, and the latest mounting information received from the sensor device by the receiving device. An abnormality detection system comprising: a determination device that compares inspection information generated based on the determination information and determines that the inspection information is abnormal when the inspection information deviates from a normal range defined for the reference information.

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