JP2013101519A - Radio tag system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio tag system capable of coping with both of an on-vehicle reader and a portable reader by using a tag capable of switching a request/response mode and an intermittent transmission mode.SOLUTION: The tag includes: control means for defining an "intermittent transmission mode" of transmitting intermittent signals including sensor information at a prescribed intermittent transmission interval as a stationary state, shifting to a "request/response mode" of transmitting response signals when request signals transmitted from the on-vehicle reader are received, and returning to the "intermittent transmission mode" after transmitting the response signals; an antenna for receiving the request signals; and an antenna for transmitting the response signals corresponding to the reception of the request signals or the intermittent signals. The on-vehicle reader includes an antenna for transmitting the request signals and an antenna for receiving the response signals. The portable reader includes an antenna for receiving the intermittent signals.

Description

  The present invention relates to a wireless tag system for exchanging information between a reader and a tag at least one of which moves.

  For example, from a tag that collects and accumulates maintenance monitoring information (sensor information) in a manhole, a reader (hereinafter referred to as an “in-vehicle reader”) mounted on a vehicle passing on a road with a manhole or a worker on a sidewalk near the manhole The present invention relates to a wireless tag system that transmits the maintenance monitoring information to a reader carried by (hereinafter referred to as “portable reader”).

FIG. 9 shows a first configuration example of a conventional wireless tag system.
In FIG. 9, a tag 80 including a sensor 81 that measures the state of a maintenance monitoring target 70 such as a bridge is an active tag that periodically transmits sensor information measured by the sensor 81 as an intermittent signal from a transmission unit 83. Yes, when the reader 61 mounted on the vehicle 60 moves to a position where the intermittent signal can be received, sensor information of the sensor 81 is collected. In the active tag, the transmission power generated in response to the transmission of the intermittent signal occupies most of the power consumption of the entire tag. Therefore, if the transmission interval of the active tag is shortened so that the reader moving at high speed can receive, the power consumption further increases, and the battery-driven operation cannot be performed for a long time.

FIG. 10 shows a second configuration example of a conventional wireless tag system (Patent Document 1).
In FIG. 10, for example, a tag 80 including a sensor 81 that measures the state of a maintenance monitoring target 70 such as a bridge receives a request signal transmitted from a reader 61 mounted on a vehicle 60 by a receiving unit 82, and Sensor information measured by the sensor 81 using a signal as a trigger is transmitted from the transmission unit 83 as a response signal, and the reader 61 receives the response signal and collects sensor information of the sensor 81. Here, by controlling the timing of the response signal between the reception unit 82 and the transmission unit 83, the sensor 81 is in a state of the maintenance monitoring object 70 while the vehicle 60 passes through the maintenance monitoring object 70. And the measurement data can be received at the timing when the vehicle 60 passes through the communication area of the transmission unit 83. In this configuration, since the response signal is transmitted in response to the request signal, power consumption can be reduced compared to a configuration using an active tag that always transmits an intermittent signal.

JP 2009-295051 A

  If it is possible to grasp the state in the manhole as an object to be monitored by using a wireless tag system without opening the lid of the entrance and exit of the manhole, the work of maintaining and inspecting the manhole is greatly simplified. When using such a wireless tag system, there are two methods for receiving a wireless signal transmitted by the tag with a reader.

  The first method uses an active tag that intermittently transmits the measurement data of the sensor 81 as shown in FIG. 9, and is hereinafter referred to as “intermittent transmission mode”. An operator carries a portable reader, proceeds on a sidewalk parallel to a road with a manhole, and receives a signal intermittently transmitted from an active tag at a position slightly away from the manhole (on the sidewalk). In order to reduce the weight, the portable reader does not have a function of transmitting a request signal like an in-vehicle reader, and includes only a receiving unit that passively receives a tag transmission signal.

  In the second method, as in the embodiment of FIG. 10, a vehicle equipped with an in-vehicle reader transmits a request signal while traveling, and a tag in the manhole receives the request signal when approaching or near the manhole. The response signal transmitted in response to the request signal is received by the in-vehicle reader, and is hereinafter referred to as “request / response mode”.

  By the way, in order to support both in-vehicle readers and portable readers without opening the manhole cover with the sensor and tag installed in the manhole, the request / response mode and intermittent transmission mode are externally applied to the tag in the manhole. It is necessary to enable switching.

  An object of the present invention is to provide a wireless tag system that uses a tag that can be switched between a request / response mode and an intermittent transmission mode, and that is compatible with both an in-vehicle reader and a portable reader.

  The present invention relates to a tag installed on a maintenance monitoring object and having a sensor for outputting sensor information obtained by measuring the state of the maintenance monitoring object, an in-vehicle reader mounted on a vehicle passing through the vicinity of the maintenance monitoring object, and a work RFID tag system comprising a portable reader carried by a person, transmitting a request signal from the in-vehicle reader, transmitting a response signal including sensor information from the tag that has received the request signal, and receiving the response signal by the in-vehicle reader In the tag, the “intermittent transmission mode” in which an intermittent signal including sensor information is transmitted at a predetermined intermittent transmission interval is set to a steady state, and a response signal is transmitted when a request signal transmitted from the in-vehicle reader is received. / Response mode ", control means for returning to" intermittent transmission mode "after transmission of the response signal, antenna for receiving the request signal, and reception of the request signal And an antenna for transmitting a response signal or an intermittent signal Flip was, onboard reader includes an antenna for transmitting the request signal, and an antenna for receiving the response signal, the portable reader comprises an antenna for receiving an intermittent signal.

  In the wireless tag system of the present invention, the tag includes an electromagnetic induction antenna that receives a request signal by an electromagnetic induction method, and a radio wave antenna that transmits a response signal or an intermittent signal according to reception of the request signal by a radio method. The in-vehicle reader is equipped with an electromagnetic induction antenna that transmits a request signal by an electromagnetic induction method and a radio wave antenna that receives a response signal by an electric wave method, and the portable reader is an electric wave antenna that receives an intermittent signal by an electric wave method. Is provided.

  In the RFID tag system of the present invention, the intermittent transmission interval of the intermittent signal, the transmission interval of the response signal, and the number of transmissions are set, and the operation setting signal for setting each parameter related to the operation of the sensor is transmitted to the tag, and the intermittent signal or response The tag is equipped with a carriage equipped with a reader that has the function of receiving signals, and the tag sets the intermittent transmission interval of the intermittent signal, the transmission interval of the response signal, and the number of transmissions according to the operation setting signal to be received. Means for setting each parameter involved.

  In the wireless tag system of the present invention, the in-vehicle reader sets the intermittent transmission interval of the intermittent signal, the transmission interval of the response signal, and the number of transmissions, and transmits an operation setting signal for setting each parameter related to the operation of the sensor to the tag. The tag includes means for setting the intermittent transmission interval of the intermittent signal, the transmission interval of the response signal, and the number of transmissions according to the operation setting signal to be received, and setting each parameter related to the operation of the sensor.

  In the wireless tag system of the present invention, the in-vehicle reader includes means for transmitting an operation setting signal for notifying information on the traveling speed of the vehicle to the tag, and the tag is a prescribed value of the transmission interval, the number of transmissions, and the transmission power of the response signal. If the vehicle traveling speed is less than or equal to the threshold value, the transmission interval of the response signal, the number of transmissions, and the transmission power are set to the prescribed values according to the received vehicle traveling speed information. Means for setting the transmission interval of the response signal to be shorter than the prescribed value, setting the number of transmissions to be greater than the prescribed value, or setting the transmission power to be higher than the prescribed value.

  In the wireless tag system of the present invention, the request / response mode and the intermittent transmission mode can be switched with one tag. In the intermittent transmission mode, sensor information can be acquired by receiving an intermittent signal using a portable reader carried by an operator. Furthermore, sensor information can be acquired by transmitting a request signal from the in-vehicle reader mounted on the vehicle to switch to the request / response mode and receiving a response signal to the request signal using the in-vehicle reader.

  In addition, the intermittent transmission mode can be set to a steady state as the operation mode of the tag, and after switching to the request / response mode by the request signal, the intermittent transmission mode can be automatically restored after the response signal is transmitted. This enables sensor information to be collected even by a portable reader that receives only intermittent signals.

  In addition, by setting the intermittent transmission interval of the intermittent signal, the transmission interval of the response signal, and the number of transmissions, and transmitting the operation setting signal for setting each parameter related to the operation of the sensor, a wireless tag system that can be operated flexibly Can be realized.

  Further, by adjusting at least one of the transmission interval, the number of transmissions, and the transmission power of the response signal transmitted from the tag according to the traveling speed of the vehicle, the in-vehicle reader responds even when the traveling speed of the vehicle becomes high. The signal can be received reliably.

It is a figure which shows the structural example at the time of the operation | movement setting of the wireless tag system of this invention. It is a figure which shows the structural example at the time of operation | use of the radio | wireless tag system of this invention. It is a figure showing an example of composition of each part at the time of operation of a radio tag system of the present invention. It is a time chart which shows an intermittent signal and a response signal. It is a state transition diagram which shows the example of a state transition of a tag. It is a time chart which shows the operation example of a tag. It is a figure which shows the other structural example of the wireless tag system of this invention. It is a figure which shows the other structural example of the wireless tag system of this invention. It is a figure which shows the 1st structural example of the conventional radio | wireless tag system. It is a figure which shows the 2nd structural example of the conventional wireless tag system.

  FIG. 1 shows a configuration example at the time of operation setting of the wireless tag system of the present invention. FIG. 1 (1) shows a configuration example of the entire system, and FIG. 1 (2) shows a configuration example of a reader and a tag.

  In FIG. 1 (1), a reader 10 mounted on a cart 1 pushed by an operator includes, for example, an electromagnetic induction antenna 11 used for transmission of an operation setting signal or a request signal of an LF band, and operation setting of, for example, an UHF band. A radio wave antenna 12 used for receiving a confirmation signal, an intermittent signal, or a response signal to the request signal is connected. There is a manhole 5 that is an object to be monitored and maintained under the road on which the carriage 1 moves, and a tag 50 installed in the manhole 5 is used for receiving, for example, an operation setting signal or a request signal in the LF band. An electromagnetic induction antenna 51 and a radio wave antenna 52 used for transmitting an operation setting confirmation signal, an intermittent signal, or a response signal in the UHF band, for example, are connected.

  The reader 10 transmits an operation setting signal or a request signal from the electromagnetic induction antenna 11, and when the electromagnetic induction antenna 11 and the electromagnetic induction antenna 51 connected to the tag 50 face each other, the operation setting is performed by the electromagnetic induction method. A signal or a request signal is transmitted from the reader 10 to the tag 50. The tag 50 is in an intermittent transmission mode in which an intermittent signal is transmitted from the radio wave antenna 52 in a steady state, and is in a request / response mode in which a response signal is transmitted from the radio wave antenna 52 when a request signal is received from the reader 10. After transmitting the response signal, the mode returns to the intermittent transmission mode. The intermittent signal or response signal is received by the radio wave antenna 12 of the reader 10. Here, in the tag 50, parameters necessary for the request / response mode or the intermittent transmission mode of the tag 50 are set in accordance with the received operation setting signal. Details of the operation setting signal will be described later.

  In FIG. 1 (2), the reader 10 generates an operation setting signal or a request signal and transmits it from the electromagnetic induction antenna 11, and an operation setting confirmation signal or intermittent signal or response received by the radio wave antenna 12. A receiving unit 14 that performs signal reception / decoding processing and displays, stores, and reads sensor information included in the intermittent signal or the response signal is provided.

  The tag 50 includes a receiving unit 53, a control unit 54, an intermittent signal processing unit 55, a response signal processing unit 56, a sensor 57, and a radio wave antenna 52 that decode the operation setting signal or request signal received by the electromagnetic induction antenna 51. The transmission part 58 connected to is provided. The control unit 54 sets parameters necessary for the intermittent transmission mode or the request / response mode in the intermittent signal processing unit 55 or the response signal processing unit 56 according to the operation setting signal, and outputs an operation setting confirmation signal to the transmission unit 58. At the same time, switching between the intermittent transmission mode and the request / response mode is controlled. Further, the control unit 54 processes the sensor information of the sensor 57 and outputs it to the intermittent signal processing unit 55 or the response signal processing unit 56. The intermittent signal processing unit 55 operates in the intermittent transmission mode in response to an instruction from the control unit 54 and outputs sensor information to the transmission unit 58 as an intermittent signal. The response signal processing unit 56 operates in the request / response mode in response to an instruction from the control unit 54, outputs the sensor information as a response signal to the transmission unit 58, and stops its operation upon completion of transmission of the response signal. The state transition between the intermittent transmission mode and the request / response mode in the control unit 54 will be described later. The transmitter 58 transmits an operation setting confirmation signal, an intermittent signal, or a response signal from the radio wave antenna 52.

  In this embodiment, the electromagnetic induction antenna 11 through which the reader 10 transmits an operation setting signal or a request signal is attached to the lower part of the carriage 1, and the carriage 1 transmits the operation setting signal or the request signal in a direction directly below, whereby the carriage 1 has the tag 50. The electromagnetic induction antenna 51 of the tag 50 receives the operation setting signal or the request signal when passing over the manhole 5 with the tag.

  The normal cart 1 has a vehicle height (from the ground to the bottom surface of the cart 1) of about 10 cm, and the depth of the manhole is almost 3 m or less. In Japan, the LF band and the HF band are used as electromagnetic induction systems, and there is often no loss of radio waves due to asphalt or soil. Therefore, if communication is possible for 3 m or more in free space, communication is possible between the electromagnetic induction antenna 51 of the tag 50 installed in the manhole and the electromagnetic induction antenna 11 attached to the lower surface of the carriage 1.

  FIG. 2 shows a configuration example during operation of the wireless tag system of the present invention. FIG. 2 (1) shows a configuration example in the case of collecting sensor information using an in-vehicle reader mounted on a traveling vehicle. FIG. 2 (2) shows a configuration example when sensor information is collected using a portable reader mainly carried by a walking worker.

  In FIG. 2 (1), an in-vehicle reader 20 mounted on the vehicle 2 includes an electromagnetic induction antenna 21 used for transmitting a request signal in the LF band, for example, and a radio wave antenna 22 used for receiving a response signal in the UHF band, for example. Is connected. There is a manhole 5 that is an object to be monitored and maintained under the road on which the vehicle 2 travels, and a tag 50 installed in the manhole 5 includes an electromagnetic induction antenna 51 used for receiving a request signal, a response A radio wave antenna 52 used for signal transmission is connected. The configuration in the manhole 5 is the same as that at the time of operation setting in FIG.

  The in-vehicle reader 20 transmits a request signal from the electromagnetic induction antenna 21, and when the electromagnetic induction antenna 21 and the electromagnetic induction antenna 51 connected to the tag 50 face each other, the in-vehicle reader transmits the request signal by the electromagnetic induction method. 20 to the tag 50. The tag 50 is in an intermittent transmission mode in which an intermittent signal is transmitted from the radio wave antenna 52 in a steady state, and is in a request / response mode in which a response signal is transmitted from the radio wave antenna 52 when a request signal is received from the in-vehicle reader 20. After the response signal is transmitted, the intermittent transmission mode is restored. The intermittent signal or response signal is received by the radio wave antenna 22 of the in-vehicle reader 20. The electromagnetic induction antenna 21 and the radio wave antenna 22 connected to the in-vehicle reader 20 are the same as the electromagnetic induction antenna 11 and the radio wave antenna 12 connected to the reader 10 shown in FIG. However, it is desirable that the radio wave antenna 22 be installed at a relatively high position so that the response signal can be received even after the vehicle 2 passes through the manhole 5.

  In FIG. 2 (2), a radio wave antenna 31 used for receiving intermittent signals is connected to a portable reader 30 carried by an operator. There is a manhole 5 which is an object to be monitored and maintained under the roadway (underground) near the sidewalk where workers walk. The tag 50 in the intermittent transmission mode transmits sensor information as an intermittent signal, and the intermittent signal is received by the radio wave antenna 31 of the portable reader 30.

FIG. 3 shows a configuration example of each part during operation of the wireless tag system of the present invention.
In FIG. 3, the in-vehicle reader 20 generates a request signal and transmits it from the electromagnetic induction antenna 21 and receives / decodes the response signal received by the radio wave antenna 22 and is included in the response signal. A receiving unit 24 that displays, stores, and reads sensor information is provided.

  The portable reader 30 includes a receiving unit 32 that performs reception / decoding processing of intermittent signals received by the radio wave antenna 31 and displays, stores, and reads sensor information included in the intermittent signals.

  The tag 50 has the same configuration as that shown in FIG. 1 (2), and includes an electromagnetic induction antenna 51, a radio wave antenna 52, a receiving unit 53, a control unit 54, an intermittent signal processing unit 55, a response signal processing unit 56, and a sensor 57. The transmitter 58 is provided.

  In the present invention, the electromagnetic induction antenna 21 to which the in-vehicle reader 20 transmits a request signal is attached to the lower part of the vehicle 2, and the vehicle 2 passes above the manhole with the tag 50 by transmitting the request signal directly downward. Sometimes, the electromagnetic induction antenna 51 of the tag 50 receives the request signal, enters the request / response mode, transmits the corresponding response signal, and enters the intermittent transmission mode after transmitting the response signal.

  The normal vehicle 2 has a vehicle height (from the ground to the lower surface of the floor of the vehicle 2) of about 20 cm, and most of the manholes have a depth of 3 m or less. In Japan, the LF band and the HF band are used as electromagnetic induction systems, and there is often no loss of radio waves due to asphalt or soil. In this case, communication is possible between the electromagnetic induction antenna 51 of the tag 50 installed in the manhole and the electromagnetic induction antenna 21 attached to the lower surface of the vehicle 2 as long as 3 m or more can be communicated in free space. It is. Actually, there are commercially available products that can communicate up to a communication distance of 5 m when the size of the electromagnetic induction antenna is about 1 m × 1 m. Since the lower surface of the vehicle 2 has a size of 1.7 m or more and a width of 1 m or more even in a small car or a light car, the electromagnetic induction antenna 51 of the tag 50 is attached by attaching the electromagnetic induction antenna 21 of about 1 m × 1 m. Communication of about 5 m is possible between the two.

The time during which the in-vehicle reader 20 and the tag 50 can transmit and receive request signals is equal to the time T ₁ (s) that the electromagnetic induction antenna 21 of the in-vehicle reader 20 passes over the electromagnetic induction antenna 51 of the tag 50. The time T ₁ (s) is calculated from the length L (m) of the electromagnetic induction antenna 21 and the vehicle moving speed V (m / s).
T ₁ = L / V
It is decided. For example, when the length L of the electromagnetic induction antenna 21 is 1.7 m and the moving speed V of the vehicle 2 is 60 km / h≈16.7 m / s, the communicable time T ₁ is about 0.1 second.

Next, if the transmission interval of the request signal is I ₁ (s) and the number of times the tag 50 is received is N ₁ (times), I ₁ = T ₁ / N ₁
Therefore, if the number N ₁ of times that the request signal is received by the tag 50 while the vehicle 2 passes is determined, the transmission interval I _{1 of the} request signal is determined. For example, when the electromagnetic induction antenna 21 having a length of 1.7 m is mounted and the request signal is received twice from the vehicle 2 traveling at 60 km / h, the transmission interval I ₁ of the request signal is about 0.05 seconds (= 50 msec). It is necessary to. In addition, since the request signal is transmitted by an electromagnetic induction method, for example, about 20 msec is necessary, but if the transmission interval is 50 msec, it can be sufficiently handled.

  By the way, the transmission unit 23 and the electromagnetic induction antenna 21 of the in-vehicle reader 20 that transmit a request signal to the electromagnetic induction antenna 51 and the reception unit 53 of the tag 50 are transmitted by the reader 10 mounted on the carriage 1 shown in FIG. The configuration is the same as that of the unit 13 and the electromagnetic induction antenna 11, and an operation setting signal can be transmitted from the in-vehicle reader 20 in addition to the request signal. However, the operation setting signal sets parameters necessary for the request / response mode and the intermittent transmission mode, as will be described later, and has a plurality of items, and each setting needs to be confirmed. On the other hand, the communication speed of the LF band performed between the electromagnetic induction antennas 21 and 51 is low (the communication capacity is small). Therefore, if it is difficult to transmit operation setting signals for all items from the traveling vehicle 2 between the opposing electromagnetic induction antennas 21 and 51 at a time, it is divided into a plurality of times or for each item. There is a method for transmitting an operation setting signal. In this case, similarly to the transmission / reception of the request signal, the transmission interval and the number of transmissions of the operation setting signal are determined according to the vehicle speed. Further, even when the operation setting signal is transmitted from the cart 1 shown in FIG. 1, in addition to transmitting all items at once, the operation setting signal may be transmitted in multiple times or for each item.

FIG. 4 shows the intermittent signal and the response signal.
The intermittent signal in FIG. 4 (1) is a signal output from the intermittent signal processing unit 55 of the tag 50 shown in FIGS. 1 (2) and 3, and here, the case where 1 minute is set as the intermittent transmission interval. Show. This intermittent transmission interval is set to, for example, 1 minute, 5 minutes, 15 minutes, or infinity by an operation setting signal from the reader 10 or the in-vehicle reader 20. When the intermittent transmission interval is set to infinity, intermittent transmission is not performed, and the tag 50 is substantially in a standby state.

  The response signal in FIG. 4 (2) is a signal output from the response signal processing unit 56 of the tag 50 shown in FIGS. 1 (2) and 3, and here, the transmission interval is 50 milliseconds and the number of transmissions is 4 times. Indicates that is set. Based on the operation setting signal from the reader 10 or the in-vehicle reader 20, the transmission interval is set to, for example, 50 milliseconds, 500 milliseconds, and the number of transmissions is set to, for example, once, four times, eight times, or the like. When the number of transmissions is set to 1, the setting of the transmission interval is meaningless.

  Here, the intermittent transmission interval of the intermittent signal and the transmission interval of the response signal are not strictly constant, but it is desirable to give random fluctuations of about 10 to 50%, for example, to the respective transmission intervals. Thereby, a plurality of manholes are close to each other, and the timing of the intermittent signal or the response signal transmitted from each tag can be shifted, so that the signals can be reliably received without colliding while repeating several transmissions.

  Next, the operation setting signal for setting the parameters of the sensor 57 shown in FIGS. 1 (2) and 3 will be described. For example, parameters set in the acceleration sensor that measures the number of vibrations of the manhole 5 include a sampling frequency for sampling the measured value of acceleration, an acceleration full scale that is the maximum value of the measured acceleration, and a threshold value of the impact strength to be counted. There is an impact detection mask time that does not count even if the acceleration exceeds the threshold value twice or more in order to count a certain impact detection threshold as one impact. The sampling frequency is set to 10 Hz, 25 Hz, 100 Hz, for example. At 100Hz, sensor data is detected 100 times per second and every 10 milliseconds. For example, ± 0.5 G or ± 1 G is set as the acceleration full scale. For example, ± 0.2 G or ± 0.4 G is set as the impact detection threshold. For example, 0, 200 milliseconds, 400 milliseconds, etc. are set as the impact detection mask time. In the case of 0, all values where the acceleration exceeds the threshold value are counted.

  For example, if each parameter is set to 100Hz, ± 0.5G, ± 0.2G, 200ms, the acceleration sensor samples acceleration at a sampling rate of 100Hz, and the number of vibrations when the impact detection threshold exceeds ± 0.2G. Is counted as one time. After that, the impact detection mask time of 200 milliseconds is not counted even if the impact detection threshold exceeds ± 0.2 G, and is counted when the impact detection threshold of ± 0.2 G is exceeded after the impact detection mask time of 200 milliseconds. Then, the operation of setting the impact detection mask time of 200 milliseconds is performed again.

  FIG. 5 is a state transition diagram showing an example of state transition of a tag. FIG. 6 is a time chart showing an example of tag operation.

  Here, an example is shown in which the tag operation setting is performed in two steps. For example, in the operation setting 1, the intermittent transmission interval of the intermittent signal, the transmission interval of the response signal and the number of transmissions are set. In the operation setting 2, the setting of the sampling frequency of the sensor, the acceleration full scale, the impact detection threshold, and the impact detection mask time is set. Do. Alternatively, the impact detection mask time may be set with the operation setting 1, and the combination thereof is arbitrary.

  5 and 6, the tag transits between states S10 to S16 for operation setting 1, operation setting 2, intermittent transmission mode, and request / response mode. The state transition is shown in FIGS. 1 (2) and 3. It is controlled by the control unit 54 of the tag 50.

  Before installing the tag in the manhole, for example, at the tag manufacturing and assembly stage, when a battery is inserted, each parameter is reset to a predetermined initial value, and the intermittent signal processing unit 55 is activated in the intermittent transmission mode (S10, t10). ). Here, intermittent transmission intervals of intermittent signals, transmission intervals and number of transmissions of response signals, sensor sampling frequency, acceleration full scale, impact detection threshold, and impact detection mask time are set to initial values.

  In the intermittent transmission mode, an intermittent signal is transmitted at an initial intermittent transmission interval, and reception confirmation can be performed by a test reader. Next, a request for operation setting 1 for setting the intermittent transmission interval of the intermittent signal is transmitted from the test reader (S11, t11). Here, infinity is set as the intermittent transmission interval of the intermittent signal, and the tag 50 is set in a standby state in which it can receive the operation setting signal or request signal in the LF band (S12, t12). This standby tag 50 is brought into the manhole 5 on site to perform installation work.

  When the tag 50 in the intermittent transmission mode and in the standby state is installed in the manhole 5, the cart 1 shown in FIG. 1 is moved over the manhole 5, and the operation setting signal of the LF band is transmitted and received between the electromagnetic induction antennas 11 and 51. . First, the operation setting 1 request for setting the intermittent transmission interval of the intermittent signal, the transmission interval of the response signal, and the number of transmissions is received (S11, t13), and the control unit 54 receives the intermittent signal processing unit 55 and the response signal processing unit 56. On the other hand, setting according to each parameter is performed, and when the setting is completed, the intermittent transmission mode is resumed, and the intermittent signal processing unit 55 starts transmission of the intermittent signal at the set intermittent transmission interval (S12, t14). Subsequently, a request for operation setting 2 for setting each parameter of the sensor 57 is received (S13, t15), and the control unit 54 sets the intermittent signal processing unit 55 and the response signal processing unit 56 according to the respective parameters. When the setting is completed, the intermittent transmission mode is resumed, and the intermittent signal processing unit 55 starts transmission of an intermittent signal including sensor information measured with the set parameters (S14, t16). In this state, the intermittent signal can be received by the reader 10 shown in FIG. 1 or the portable reader 30 shown in FIGS. 2 and 3, and the operation of the tag is started.

  Next, the vehicle 2 on which the in-vehicle reader 20 is mounted passes through the manhole, during which the LF band request signal is transmitted and received between the electromagnetic induction antennas 21 and 51, and the control unit 54 that has received the request signal receives the request / The system shifts to the response mode and activates the response signal processing unit 56 (S15, t17). The response signal processing unit 56 generates a response signal including sensor information with the reception of the request signal as a trigger, transmits the response signal at the transmission interval and the transmission count set in the operation setting 1, and stops the operation when the transmission ends. Under the control of the control unit 54, the intermittent transmission mode is entered and the intermittent signal processing unit 55 is activated (S16, t18).

  As described above, since the tag 50 shifts from the request / response mode to the intermittent transmission mode when the transmission of the response signal is completed, the intermittent operation including the sensor information is performed even if an operator carrying the portable reader 30 comes to the manhole after that. The signal can be received.

  In addition, during operation of the tag 50, it is possible to transmit an operation setting signal (request for operation setting 1 or request for operation setting 2) from the traveling vehicle 2 and reset each parameter of the tag 50. For example, the response signal can be received more reliably by adjusting the transmission interval and the number of transmissions of the response signal according to the vehicle speed. It is also possible to collect more appropriate sensor information by adjusting each parameter of the sensor 57 by analyzing sensor information.

  Here, in order for the traveling vehicle 2 to reliably receive the response signal from the tag 50, one of the response signal transmission interval, the number of transmissions, the transmission power, or a combination thereof is appropriately selected according to the traveling speed of the vehicle 2. An example of changing the setting will be described. The in-vehicle reader 20 transmits information on the transmission interval of the response signal, the number of transmissions, the prescribed value of the transmission power, and the traveling speed information of the vehicle 2 as the operation setting signal transmitted together with the request signal. Note that the response signal transmission interval, the number of transmissions, and the prescribed values of transmission power may be set in advance from the reader 10 of the carriage 1. The control unit 54 activates the response signal processing unit 56 in response to the request signal, and keeps the response signal transmission interval, the number of transmissions, and the transmission power at the prescribed values if the traveling speed of the vehicle 2 is equal to or less than the threshold value. . On the other hand, when the traveling speed of the vehicle 2 is higher than the threshold value, the response signal can be expected to be received a certain number of times even in a short time by making the transmission interval of the response signal shorter than the specified value. Alternatively, when the traveling speed is higher than the threshold value, the response signal is transmitted more times than the specified value, thereby facilitating reception due to the time diversity effect even when the reception environment is not good. Alternatively, when the traveling speed is higher than the threshold value, the reception power is improved by making the transmission power of the response signal higher than the specified value to facilitate reception.

  In FIG. 1, a control signal for turning on / off the operation of the sensor 57 may be transmitted as an operation setting signal for the LF band transmitted to the tag 50. For example, as shown in FIG. 6, the sensor 57 is turned on at the timing when the parameters of the tag 50 are reset to the initial values and the intermittent transmission mode is set (S10, t10), and the sensor is turned off at the timing of shifting to the operation setting 1. (S11, t11), the intermittent transmission interval is set to infinity and a standby state is entered. Further, the carriage 1 equipped with the reader 10 moves over the manhole 5, transmits the operation setting signal of the LF band, and turns on the sensor 57 at the timing when the tag 50 receiving the operation setting signal performs the operation setting 2. (S13, t15), and thereafter, the sensor 57 remains on. Further, an LF band operation setting signal for controlling on / off of the sensor 57 may be transmitted from the in-vehicle reader 20 of the vehicle 2 traveling on the manhole 5 to the tag 50.

  In the above description, the tag 50 is installed in the manhole 5, and an example in which sensor information is collected using the in-vehicle reader 20 mounted on the vehicle 2 passing over the tag 50 or the portable reader 30 carried by a walking worker is shown. . However, the installation location of the tag 50 including the sensor is not limited to the manhole 5, and may be installed in, for example, the utility pole 7 shown in FIG. 7 or the closure 6 attached to the electric wire or cable installed on the utility pole 7. . In this case, the electromagnetic induction antenna 21 mounted on the vehicle 2 (or the carriage 1) is installed on the ceiling portion of the vehicle 2 (or the carriage 1), and the LF band request signal and operation setting signal are directed upward. You may send it. At this time, the UHF band response signal transmitted from the tag 50 is received by the radio wave antenna 22 mounted on the vehicle 2 (or the carriage 1). The sensor installed in the tag 50 is, for example, a tilt sensor that measures the tilt of the utility pole, a strain sensor that measures the strain or temperature of the closure 6, and a temperature sensor.

  In the above description, the electromagnetic induction antenna 51 and the radio wave antenna 52 of the tag 50 are separated from each other, and use different radio systems (for example, LF band electromagnetic induction system, for example, UHF band radio system). An example of transmitting and receiving signals was shown. However, as shown in FIG. 8, these may be transmitted and received with the same antenna by the same wireless system.

  In the configuration example illustrated in FIG. 8, the transmission unit 23 and the reception unit 24 of the in-vehicle reader 20 illustrated in FIG. 3, and the reception unit 53 and the transmission unit 58 of the tag 50 are a single transmission / reception unit 25 and a transmission / reception unit 59, respectively. Transmission and reception are performed via the two radio wave antennas 22 and 52. The request signal is transmitted from the transmission / reception unit 25 of the in-vehicle reader 20 via the radio wave antenna 22, received by the transmission / reception unit 59 via the radio wave antenna 52 of the tag 50, and input to the control unit 54. The intermittent signal output from the intermittent signal processing unit 55 or the response signal output from the response signal processing unit 56 under the control of the control unit 54 is transmitted from the transmission / reception unit 59 via the radio wave antenna 52. The intermittent signal is received by the receiving unit 32 via the radio wave antenna 31 of the portable reader 30, and the response signal is received by the transmitting / receiving unit 25 via the radio wave antenna 22 of the in-vehicle reader 20. Here, the control unit 54, the intermittent signal processing unit 55, and the response signal processing unit 56 of the tag 50 perform exactly the same operation as the tag 50 shown in FIG.

  Similarly, for the operation setting signal for the LF band and the operation setting confirmation signal for the UHF band shown in FIG. 1 (2), the transmission unit 13 and the reception unit 14 of the reader 10 are used as one transmission / reception unit. Can be transmitted / received using the transmission / reception unit 59 and the radio wave antenna 52 of the tag 50 shown in FIG.

DESCRIPTION OF SYMBOLS 1 Car 2 Vehicle 5 Manhole 6 Closure 7 Electric pole 10 Reader 11 Electromagnetic induction antenna 12 Radio wave antenna 13 Transmitter 14 Receiver 20 Car-mounted reader 21 Electromagnetic induction antenna 22 Radio wave antenna 23 Transmitter 24 Receiver 25 Transmitter / receiver 30 Mobile Reader 31 Radio wave antenna 32 Receiving unit 50 Tag 51 Electromagnetic induction antenna 52 Radio wave antenna 53 Receiving unit 54 Control unit 55 Intermittent signal processing unit 56 Response signal processing unit 57 Sensor 58 Transmission unit 59 Transmission / reception unit 60 Vehicle 61 Reader 70 Maintenance monitoring Object 80 Tag 81 Sensor 82 Receiver 83 Transmitter

Claims (5)

Carried by a tag installed on a maintenance monitoring object and having a sensor that outputs sensor information obtained by measuring the state of the maintenance monitoring object, and an in-vehicle reader and worker mounted on a vehicle passing near the maintenance monitoring object. A wireless tag configured to transmit a request signal from the in-vehicle reader, transmit a response signal including the sensor information from the tag that has received the request signal, and receive the response signal by the in-vehicle reader In the system,
The tag sets an “intermittent transmission mode” in which an intermittent signal including the sensor information is transmitted at a predetermined intermittent transmission interval, and transmits the response signal when the request signal transmitted from the in-vehicle reader is received. Control means for returning to the “intermittent transmission mode” after transmission of the response signal, an antenna for receiving the request signal, and the response signal in response to reception of the request signal or An antenna for transmitting the intermittent signal;
The in-vehicle reader includes an antenna that transmits the request signal and an antenna that receives the response signal.
The wireless tag system, wherein the portable reader includes an antenna that receives the intermittent signal. The wireless tag system according to claim 1,
The tag includes an electromagnetic induction antenna that receives the request signal by an electromagnetic induction method, and a radio wave antenna that transmits the response signal or the intermittent signal according to reception of the request signal by a radio method.
The in-vehicle reader includes an electromagnetic induction antenna that transmits the request signal by an electromagnetic induction method, and a radio wave antenna that receives the response signal by a radio wave method,
The wireless tag system, wherein the portable reader includes a radio wave antenna that receives the intermittent signal by a radio wave system. The wireless tag system according to claim 1,
The intermittent transmission interval of the intermittent signal, the transmission interval of the response signal, and the number of transmissions are set, an operation setting signal for setting each parameter related to the operation of the sensor is transmitted to the tag, and the intermittent signal or the response signal is transmitted. It has a carriage equipped with a reader that has the function of receiving,
The tag includes means for setting an intermittent transmission interval of the intermittent signal, a transmission interval of the response signal, and the number of transmissions according to the operation setting signal to be received, and setting each parameter related to the operation of the sensor. A wireless tag system characterized by The wireless tag system according to claim 1,
The in-vehicle reader includes means for setting an intermittent transmission interval of the intermittent signal and a transmission interval and the number of transmissions of the response signal, and transmitting an operation setting signal for setting each parameter related to the operation of the sensor to the tag,
The tag includes means for setting an intermittent transmission interval of the intermittent signal, a transmission interval of the response signal, and the number of transmissions according to the operation setting signal to be received, and setting each parameter related to the operation of the sensor. A wireless tag system characterized by The wireless tag system according to claim 1,
The in-vehicle reader includes means for transmitting an operation setting signal for notifying information on the traveling speed of the vehicle to the tag,
The tag has specified values for the transmission interval, the number of transmissions, and transmission power of the response signal, and if the vehicle traveling speed is equal to or less than a threshold according to the received information on the traveling speed of the vehicle, the response signal The transmission interval, the number of transmissions, and the transmission power are set to the prescribed values, and if the traveling speed of the vehicle exceeds a threshold value, the transmission interval of the response signal is set shorter than the prescribed value, or the number of transmissions is set to the prescribed value. The wireless tag system comprising: a means for setting more or setting transmission power higher than the specified value.

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