JP6033570B2 - Displacement sensor, sensor node, and automatic tension measuring method - Google Patents

Description

  The present invention relates to an automatic tension adjusting device for an overhead wire, and more particularly to a displacement sensor, a sensor node, and an automatic tension measuring method for measuring a spring expansion / contraction state of a spring type automatic tension adjusting device.

An overhead wire (trolley wire) for supplying electric power to a railway vehicle such as a train via a pantograph is suspended from pillars built at regular intervals in a state where a tension is applied. Such an overhead wire is generally made of copper wire, and the tension changes because it expands and contracts daily due to changes in temperature. In addition, the tension changes due to aging, wear, elastic elongation, column inclination, and the like. When the tension drops and the overhead wire becomes slack, the contact of the pantograph becomes unstable. Moreover, when the tension increases, the overhead wire may be cut. In order to maintain the integrity of the overhead line, it is necessary to keep the tension of the overhead line constant.
Therefore, an automatic tension adjusting device such as a spring-type automatic tension adjusting device is installed at the terminal end of the overhead wire, thereby absorbing the expansion and contraction of the overhead wire so that the tension becomes constant.
Furthermore, in order to maintain the soundness of the overhead wire, it is necessary to inspect whether there is any abnormality in the automatic tension adjusting device that applies a constant tension to the overhead wire. For this reason, it is necessary to monitor the expansion and contraction state of the spring for each of the automatic tension adjustment devices installed on each overhead wire, and the maximum and minimum values of the spring displacement are regularly kept within the normal operating range. It is necessary to check that there is.

A method using a displacement sensor and a permanent magnet has been proposed as a method for measuring the expansion / contraction state of the spring of the spring type automatic tension adjusting device (see, for example, Patent Document 1).
According to Patent Document 1, a permanent magnet is attached to an object that moves at high speed on a displacement sensor. When the permanent magnet passes near each magnetic sensor element, the magnetic sensor element senses the magnetism of the permanent magnet. Output a pulse. Therefore, it is possible to detect the position of the object by counting the total number of pulses output by the magnetic sensor element.
Patent Document 2 shows a magnetic material that is magnetized when a magnetic field is applied, a magnetic sensor element that senses the magnetic field of the magnetized magnetic material, and whether or not the magnetic sensor element senses a predetermined magnetic field. There has been proposed a displacement measuring method comprising output means for outputting sensing result information.

JP-A-3-233302 JP 2009-74991 A

However, in Patent Document 1, since the displacement is measured by counting the total number of pulses output by each magnetic sensor element, it is necessary to always supply power to the displacement sensor and the counter that counts the number of pulses. Therefore, there is a problem that power consumption cannot be suppressed.
Further, the measurement method of Patent Document 2 records the displacement of the spring by magnetizing the magnetic material, and does not consume power except during measurement. However, in order to clear (demagnetize) a magnetic material that has been once magnetized, there has been a problem that an inspector needs time to demagnetize the magnetic material using a demagnetizing coil.
The present invention has been made in view of such a situation, and it is not necessary to constantly supply power to the displacement sensor, and further, by measuring the displacement amount at a high speed, a displacement sensor and a sensor node that suppress power consumption, and Provide an automatic tension measurement method.

  In order to solve the above problems, a displacement sensor of the present invention includes a plurality of magnetic sensor elements that detect magnetism from a magnet and output a magnetic detection signal, and a specific magnetic sensor element among the plurality of magnetic sensor elements. A displacement sensor comprising: a power source selecting means for selecting and supplying power, wherein each of the magnetic sensor elements is selected by the power source selecting means and operates when receiving power supply, It is a first feature of the present invention that, when sensed, a sensing signal indicating that magnetism has been sensed is output.

  In order to solve the above problems, the sensor node of the present invention measures the displacement sensor of the first feature of the present invention, a clock unit that provides time information, and the length of expansion and contraction of the spring of the automatic tension adjusting device. A recording unit for recording data, a communication unit for transmitting the measurement data recorded in the recording unit to the gateway, and acquiring the time information, and controlling the displacement sensor if the acquired time information is a measurement time Then, the extension / contraction length of the spring of the automatic tension adjusting device is measured based on the sensing signal from the displacement sensor, recorded as measurement data in the recording unit, and if it is a transmission time, the measurement recorded in the recording unit And a control unit that reads data and transmits the data from the communication unit to the gateway.

  In the sensor node according to the second aspect of the present invention, the control unit selects a specific magnetic sensor element by the power source selection unit and supplies power, and outputs the detected signal from the selected magnetic sensor element. It is a third feature of the present invention that includes a determination unit that determines the position of the magnet based on the recording unit and a recording unit that records a management number uniquely assigned to the magnetic sensor element that outputs the sensing signal.

  In the sensor node of the second feature or the third feature of the present invention, a magnetic sensor element that senses magnetism in the previous measurement recorded in the recording unit at the time of the current measurement is selected by the power source selection unit, and a power source is selected. And determining the position of the magnet by the determination means is a fourth feature of the present invention.

  In the sensor node of the second feature or the third feature of the present invention, the temperature measuring means for measuring the outside air temperature, and the recording means, the first temperature acquired by the temperature measuring means during the previous measurement, A first management number that is uniquely assigned to the magnetic sensor element that has sensed magnetism during the previous measurement is recorded, the first temperature, the second temperature acquired by the temperature measurement means during the current measurement, and the first From the management number, there is an estimation means for estimating the second management number of the magnetic sensor element that is most likely to sense magnetism at the time of measurement this time, and the control unit obtains the second management number obtained by the estimation means Is selected by the power source selection means, the power is supplied, and the position of the magnet is determined by the determination means. And features.

In the sensor node of the second feature or the third feature of the present invention,
Reference is made to a temperature measuring means for measuring the outside air temperature, a temperature information acquired by the temperature measuring means at the time of past measurement, a database for recording a management number uniquely assigned to a magnetic sensor element that senses magnetism, and the database Determination means for determining a management number of a magnetic sensor element having the highest possibility of sensing magnetism from temperature information recorded in the database, and before the measurement, the current temperature is measured by the temperature measurement means. The magnetic sensor element to which the acquired temperature and the management number acquired from the determination means are assigned, and the adjacent magnetic sensor element are selected by the power supply selection means, power is supplied, and the magnet is detected by the determination means. It is a sixth feature of the present invention to determine the position of.

  In order to solve the above-mentioned problem, the automatic tension measuring method of the present invention includes a plurality of magnetic sensor elements that sense magnetism from the magnet constituting the displacement sensor of the first feature of the present invention and output a magnetic sensing signal. When a power supply is supplied and a sensing signal is output from the supplied magnetic sensor element, the extension / contraction length of the spring of the automatic tension adjusting device is measured based on the position of the magnetic sensor element. The seventh feature of the present invention.

  In the automatic tension measuring method according to the seventh aspect of the present invention, time information is acquired, and based on the acquired time information, the displacement sensor is controlled at a predetermined first time to detect from the displacement sensor. Receiving the signal, measuring the extension / contraction length of the spring of the automatic tension adjusting device on the basis of the magnetic sensor element of the displacement sensor that has received the sensing signal, recording it as measurement data, and at a predetermined second time It is an eighth feature of the present invention that the recorded measurement data is read and transmitted to the gateway.

According to the present invention, it is not necessary to constantly supply power to the displacement sensor, and the displacement amount can be measured at a higher speed, so that a displacement measurement sensor node with reduced power consumption can be provided.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a figure which shows the structure of one Example of the automatic tension adjusting device which concerns on this invention. It is a block diagram which shows the structure of one Example of the displacement sensor of this invention. It is a block diagram which shows the structure of one Example of the sensor node of this invention. It is a flowchart which shows one Example of the intermittent operation | movement of the sensor node of this invention. It is a figure which shows the structure of the automatic tension adjusting device which concerns on this invention. It is a flowchart explaining one Example of the displacement measurement process of the sensor node of this invention. It is a flowchart explaining one Example of the displacement measurement process of the sensor node of this invention. It is a block diagram which shows the structure of one Example of the sensor node of this invention. It is a flowchart explaining one Example of the displacement measurement process of the sensor node of this invention.

  The present invention relates to a spring-type automatic tension adjusting device provided at a predetermined interval on an overhead line installed along a railway line in order to automatically adjust the tension of the overhead line. Since the sensor node for measuring the degree of expansion and contraction of the spring of the spring type automatic tension adjusting device and transmitting the measurement data to the gateway is installed in the railway facility, it is difficult to use a commercial power source. For this reason, a capacitor charged in advance is often used as a power source. Also. It is also possible to install a solar cell, generate power with the installed solar cell, and store the generated power in a capacitor. Thus, since a solar cell or a capacitor must be used as a power source, it is desirable that the displacement sensor and sensor node used in the spring type automatic tension adjusting device be power saving.

The sensor node of the present invention is a displacement sensor, in which magnetic sensor elements are arranged in a straight line at predetermined intervals in the direction of expansion and contraction of the spring, and the position of the magnetic sensor element that senses the magnetism of the fixed permanent magnet is examined and measured. The length of expansion and contraction of the spring is measured from the position of the magnetic sensor element. The measurement may be performed at time intervals of several tens of minutes to several hours, and the measured measurement data is recorded in the recording unit. As the measurement data, the maximum and minimum values of expansion and contraction within a predetermined time (for example, 24 hours, one week, etc.) are recorded as measurement data. The recorded measurement data has a data amount of several bytes at most.
Furthermore, power is not supplied to all of the plurality of magnetic sensor elements at one time, and is always supplied to only one of the magnetic sensor elements. When the magnetism is sensed by operating one by one, a sensing signal is transmitted to the sensor node. Since the sensor node knows the magnetic sensor element that has been turned on (supplied), it can measure the length of expansion and contraction of the spring as position information in accordance with the position of the magnetic sensor element that has output the sensing signal.

The measurement data recorded in the recording unit is read out and, in the form of packet data with an ID for identifying the overhead line, for a train passing through the railway track as a gateway, a predetermined time interval (for example, Sent every few seconds). In order to save power, the radio equipment mounted on the train does not take a reception response, but transmits measurement data unilaterally.
In a train equipped with a receiver or radio that receives measurement data, the receiver or radio receives and records the measurement data transmitted when the train passes. Since the measurement data has a small data amount of about several bytes, it can be received while a train having a normal operation speed (for example, 100 km / h) passes.
This record is then data processed and used to maintain overhead line integrity.

  Embodiments of the present invention will be described below with reference to the drawings. In the description of each drawing, the same reference numerals are assigned to components having the same function, and the description is omitted as much as possible to avoid duplication.

  In Example 1 of the present invention, in the spring type automatic tension adjusting device, an example in which each magnetic sensor element of the displacement sensor measures the amount of displacement of the spring by sensing magnetism from a permanent magnet will be described with reference to FIGS. Will be described.

  FIG. 1 is a diagram showing a configuration of an embodiment of an automatic tension adjusting device according to the present invention. 150 is an overhead wire, 100 is a spring type automatic tension adjusting device (hereinafter referred to as STB) that automatically adjusts the tension of the overhead wire 150 to a predetermined value, 160 is a support for fixing the STB 100, and 161 and 162 are STB 100 to the support 160. It is a fixing tool to fix. In the STB 100, 101 is a storage cylinder for storing a spring (not shown), 102 is a scale, 103 is a fixed gauge, 104 is an inner middle cylinder, and 105 is an outer middle cylinder. 1 and FIG. 5 described later are also used in the second to fourth embodiments.

In FIG. 1, the STB 100 includes a spring, a scale scale 102, a fixed gauge 103, a storage cylinder 101 that stores the spring, an inner middle cylinder 104, and an outer middle cylinder 105. Here, the spring is stored in the storage cylinder 101 and cannot be seen from the outside. Hereinafter, functions for each configuration of the STB 100 will be described.
The spring expands and contracts in accordance with the tension of the overhead wire, thereby keeping the tension of the overhead wire constant.
104 is for storing a spring. Further, since the cylinder 104 is connected to the support column 106, it is in a fixed position regardless of the expansion / contraction state of the spring.

Since this spring is stored in the storage cylinder 101, the inspector cannot confirm the expansion / contraction state of the spring itself from the appearance. Therefore, as shown in FIG. 1, a scale scale 102 and a fixed gauge 102 are attached to the STB 100. Since the fixed gauge 103 is connected to the storage cylinder 101, the fixed gauge 103 is always in a fixed position regardless of the expansion / contraction state of the spring.
The scale 102 is connected to a spring, and is displaced in the direction of an arrow parallel to the storage cylinder 101 according to the expansion / contraction state of the spring. Further, the scale scale 102 is engraved with a predetermined scale, and the displacement amount of the spring can be confirmed by reading the scale at the intersection of the fixed gauge 103 fixed to the storage cylinder 101 and the scale scale 102. .

As shown in FIG. 1, an STB 100, which is one of automatic tension adjusting devices, adjusts the tension of an overhead wire using the elasticity of a spring. As described above, the STB 100 periodically checks whether the maximum and minimum values of the spring displacement are within the normal operating range, and an abnormality occurs between the current inspection and the past inspection. It is necessary to check whether it is not.
Therefore, a sensor node having the displacement sensor 200 mounted on the STB 100 is provided, and the amount of spring displacement is measured. An embodiment of the sensor node of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of an embodiment of the sensor node of the present invention. 300 is a sensor node, 200 is a displacement sensor, 502 is a connection cable, 201 is a magnetic sensor element of the displacement sensor 200, 302 is a control unit, 303 is a clock unit, 304 is a recording unit, 305 is a communication unit, 301 is a control unit 302 , A local area network (LAN) for mutual communication between the clock unit 303, the recording unit 304, and the communication unit 305.

3, the sensor node 300 includes a control unit 302, a clock 303, a recording unit 304, a communication unit 305, a LAN 301, and a displacement sensor 200 for measuring the amount of spring displacement of the STB 100. However, the power supply line 204, the magnetic sensing line 205, the ground line 206, and the selection line 207 that connect the control unit 302 and the displacement sensor 200 are omitted. Details of the power supply line 204, the magnetic sensing line 205, the ground line 206, and the selection line 207 will be described later. Further, in the configuration of the sensor node 300 (or sensor node 800 described later) in the first to fourth embodiments, solar cells, capacitors, and the like that are not directly related to the present invention are omitted. Hereinafter, each function of the sensor node 300 according to an embodiment of the present invention will be described.
The control unit 302 controls the clock unit 303, the recording unit 304, the communication unit 305, and the displacement sensor 200. A series of operations of the control unit 302 will be described later.
The clock unit 303 provides time information to the control unit 302. Based on the time information acquired from the clock unit 303, the control unit 302 determines the measurement time, the measurement information transmission time, and the intermittent operation time.
The recording unit 304 records a maximum value and a minimum value (hereinafter simply referred to as measurement data) of the spring displacement acquired by a measurement process described later.
The communication unit 305 transmits measurement data recorded in the recording unit 304 from an antenna (not shown) to the gateway.

  The sensor node 300 periodically measures the expansion / contraction state of the spring of the STB 100 using the displacement sensor 200 (for example, every several tens of minutes, every several hours, etc.), and periodically (for example, every few seconds, several minutes). And so on) to the gateway. Here, the sensor node 300 is a sensor device equipped with a communication function, and the gateway collects measurement information measured by the sensor node 300.

Further, since it is difficult to secure a commercial power source in the railway site, the sensor node 300 is driven by a solar battery, so that power saving is required.
In the STB 100, it has already been explained that the expansion / contraction state of the spring can be grasped by the scale engraved on the scale scale 102.
In actual operation, it is necessary to continuously check whether the maximum and minimum values of the spring displacement are within the normal operating range. Therefore, a means for electrically measuring the amount of displacement of the spring using the sensor node 300 including the displacement sensor 200 in the present embodiment will be described next.

The displacement sensor 200 is one in which one or more magnetic sensor elements 201 are arranged in a straight line at a predetermined interval. Normally, one or more magnetic sensor elements 201 are arranged on a straight line at equal intervals. FIG. 2 is a block diagram showing the configuration of an embodiment of the displacement sensor 200 of the present invention. 201_1 is a magnetic sensor element 1, 201_2 is a magnetic sensor element 2, 201_3 is a magnetic sensor element 3,..., 201_M is a magnetic sensor element M, 203 is a demultiplexer, 204 is a power supply line, 205 is a magnetic sensing line, 206 Is a ground line, 207 is a selection line, 502 is a connection cable in which the power supply line 204, the magnetic sensing line 205, the ground line 206, and the selection line 207 are bundled. Here, M is a natural number of 2 or more. In addition, the magnetic sensor element 201_1, 201_2, 201_3,...
The displacement sensor 200 includes a magnetic sensor element 201 and a demultiplexer 203 for selectively supplying power to the magnetic sensor element 201.

2 and 3, the magnetic sensor element 201 outputs a sensing signal to the control unit 302 of the sensor node 300 via the magnetic sensing line 205 when sensing magnetism from a permanent magnet 501 described later.
The control unit 302 receives the sensing signal output from any one of the magnetic sensor elements 201 and identifies the magnetic sensor element 201 that has output the sensing signal, thereby grasping that the magnetic sensor element 201 senses magnetism. .
The demultiplexer 203 is supplied with power from the power supply line 204, selects a magnetic sensor element 201 to be used from one or more magnetic sensor elements 201, and supplies power to the selected magnetic sensor element 201.
The demultiplexer 203 receives a control signal for selecting one of the power supply and the magnetic sensor element 201 from the control unit 302 of the sensor node 300. The demultiplexer 203 selects one of the magnetic sensor elements 201 based on the input control signal, and supplies the selected magnetic sensor element 201 with the power supplied from the sensor node 300.

The magnetic sensor element 201 operates when power is supplied from the demultiplexer 203. When the magnetic sensor element 201 senses magnetism, it outputs a sensing signal to the control unit 302 via the magnetic sensing line 205. Thereafter, a control signal is output to the output multiplexer 203 so as to cut off the power supply to all the magnetic sensor elements 201, and the demultiplexer 203 cuts off the power supply to all the magnetic sensor elements 201. In the case of Example 3 or Example 4 described later, a sensing signal is output to the control unit 802.
The magnetic sensing line 205 is a circuit for notifying the control unit 302 of a sensing signal output when the magnetic sensor element 201 senses magnetism.
The power supply line 204 is a circuit for supplying power to the magnetic sensor element 201. The power supply line 204 supplies power only to the magnetic sensor element 201 to be used among the one or more magnetic sensor elements 201 via the demultiplexer 203.
The ground line 206 grounds the magnetic sensor element 201.
A control signal for controlling the demultiplexer 203 is transmitted from the control unit 302 to the selection line 207. The control unit 302 controls the demultiplexer 203 by the selection line 207 and supplies power only to the magnetic sensor element 201 to be used among the one or more magnetic sensor elements 201.

Next, with reference to FIG. 5, an embodiment in which the sensor node 300 is installed in the STB 100 of FIG. 1 will be described. FIG. 5 is a diagram showing a configuration of an embodiment of the automatic tension adjusting device according to the present invention. Reference numeral 500 denotes an STB, and reference numeral 501 denotes a permanent magnet.
In the embodiment of FIG. 5, a displacement sensor 200 is provided on the scale scale 102. In order to measure the amount of spring displacement using the displacement sensor 200, a permanent magnet 501 is provided on the fixed gauge 103.
In FIG. 5, among the magnetic sensor elements 201 in the displacement sensor 200, the magnetic force and the installation position of the permanent magnet 501 are detected so that the magnetism from one or several permanent magnets 501 existing in the vicinity of the permanent magnet 501 can be sensed. Adjust.
However, for convenience, the sensor node 300 is attached to the storage cylinder 101 in FIG. 5.
Next, the intermittent operation of the sensor node 300 according to the first embodiment will be described with reference to FIGS. 2, 3, 5, and 4. FIG. 4 is a flowchart showing an embodiment of the intermittent operation of the sensor node of the present invention. While the sensor node of the present invention is operating, a series of operations in steps S401 to S410 described below are executed by the control unit 302 of the sensor node 300 controlling the sensor node 300 and the displacement sensor 200.

In the measurement time confirmation step S401, the control unit 302 acquires time information from the clock unit 303 when the sensor node 300 is turned on, and determines whether it is time to measure the spring displacement. If it is determined that it is the time to measure (Yes), the process proceeds to step S402. If it is determined that it is not the time to measure (No), the process proceeds to step S407.
In the maximum value / minimum value reading step S402, the control unit 302 reads the measurement data (the maximum value and the minimum value of the spring displacement) recorded in the recording unit 304, and proceeds to the processing of the measurement step S403.
In the measurement step S403, the control unit 302 measures the displacement of the spring displacement amount using the displacement sensor 200, and proceeds to the processing of the maximum value / minimum value confirmation step S404. A series of measurement operations will be described later.

  In the maximum value / minimum value confirmation step S404, the control unit 302 compares the measurement data read from the recording unit 304 in the maximum value / minimum value reading step S402 with the displacement amount of the spring acquired in the measurement step S403. When the spring displacement P acquired in the measurement step S403 is larger than the maximum value Dmax of the measurement data read from the recording unit 304 (P> Dmax), or from the minimum value Dmin of the measurement data read from the recording unit 304, When the spring displacement P acquired in the measurement step S403 is small (P <Dmin), the process proceeds to the write step S405. In other cases (Dmin ≦ P ≦ Dmax) (the spring displacement P acquired in the measurement step S403 is equal to or larger than the minimum value Dmin of the measurement data read from the recording unit 304 and read from the recording unit 304) If the measured data is less than or equal to the maximum value Dmax), the process proceeds to the sleep processing step S406.

In the writing step S405, the control unit 302 writes the spring displacement P acquired in the measurement step S403 in the recording unit 304 in the recording unit 304, and proceeds to the processing in the sleep processing step S406.
In sleep processing step S406, the control unit 302 causes the sensor node 300 to transition to the sleep state in order to suppress the power consumption of the sensor node 300. The sleep state here refers to a state in which the recording unit 304, the communication unit 305, and the displacement sensor 200 of the sensor node 300 are turned off. This transition can suppress the power consumption of the sensor node 300 as much as possible.

  In the active process S408, the control unit 302 causes the sensor node 300 to transition to the sleep state until a predetermined time elapses from the time when the sleep process step S406 transitions to the sleep state. And after predetermined time passes, the sensor node 300 is changed to an active state, and it transfers to the process of transmission time confirmation step S408. Here, the active state means that each function of the sensor node 300 and the displacement sensor 200 can be used immediately. For example, power is supplied again to the recording unit 304, the communication unit 305, and the displacement sensor 200 of the sensor node 300.

In transmission time confirmation step S <b> 408, the control unit 302 acquires time information from the clock unit 303. Then, based on the acquired time, it is determined whether or not it is time to transmit measurement data to the gateway. If it is time to transmit the measurement data to the gateway, the process proceeds to the maximum value / minimum value reading step S409. If it is not the time to send the measurement data to the gateway, the process proceeds to the measurement time confirmation step S401.
In the maximum value / minimum value reading step S409, the control unit 302 reads the measurement data from the recording unit 304, and proceeds to the processing of the transmission processing step S410.
In the transmission processing step S410, the control unit 302 controls the communication unit 305 to transmit the measurement data read to the gateway, and proceeds to the processing of the measurement time confirmation step S401.
The above is an example of the intermittent operation of the sensor node 300 in the first embodiment.

When measuring the amount of displacement of the spring, the controller 302 turns on the power of the magnetic sensor element 201 at the left end of the displacement sensor 200. Next, it is determined whether the magnetic sensor element 201 that has been turned on senses magnetism from the permanent magnet 501. If magnetism is sensed, it is determined that there is a permanent magnet 501 near the magnetic sensor element 201. After the power source of the magnetic sensor element 201 is turned off, the measurement is finished.
Conversely, when the magnetic sensor element 201 does not sense magnetism, the power of the magnetic sensor element 201 is turned off, and then the power of the magnetic sensor element 201 adjacent to the right is turned on to perform the same processing. As described above, it is investigated whether the magnetism from the permanent magnet 501 is sensed in order from the leftmost magnetic sensor element 201.
In the second embodiment, it is assumed that the displacement sensor 200 includes M magnetic sensor elements 201, and a management number is uniquely assigned to the magnetic sensor element 201. Here, for the sake of convenience, the management number of the leftmost magnetic sensor element 201_1 is 1, the management number of the right-side magnetic sensor element 201_2 is 2, and the management number of the rightmost magnetic sensor element 201_M is M.

  Next, an example of detailed operation of the measurement step S403 in the embodiment of FIG. 4 will be described with reference to FIG. FIG. 6 is a flowchart for explaining an embodiment of the sensor node displacement measurement process of the present invention. This series of operations is executed by the control unit 302 of the sensor node 300 controlling the sensor node 300 and the displacement sensor 200.

When the measurement step S403 is started, in the management number initialization step S601, the control unit 302 sets N to 1 (N = 1), and proceeds to the processing of the management number determination step S602.
In the management number determination step S602, it is determined whether N is equal to or less than the total number M of the magnetic sensor elements 201. If it is determined that N is equal to or less than M (N ≦ M), the process proceeds to the power-on step S603. If it is determined that N is greater than M (N> M), the process proceeds to measurement failure output step S608.
In the measurement failure output step S608, the control unit 302 writes data indicating that the measurement has failed in the recording unit 304 because all the magnetic sensor elements 201 cannot sense the magnetism from the permanent magnet 501.
In the power-on step S603, the control unit 302 powers on the magnetic sensor element 201_N, and the process proceeds to the magnetic detection determination step S604. Initially, since N is 1, the determination is started from the leftmost magnetic sensor element 201_1. At this time, when the magnetic sensor element 201_N that is turned on senses the magnetism of the permanent magnet 501, it outputs a sensing signal to the controller 302 via the magnetic sensing line 205. If no magnetism is detected, no detection signal is output.

In the magnetic detection determination step S604, the control unit 302 determines whether or not the magnetic sensor element 201_N has sensed magnetism from the permanent magnet 501. When it is determined that the magnetic sensor element 201_N has not sensed the magnetism from the permanent magnet 501, the process proceeds to the power-off step S606. If it is determined that the magnetic sensor element 201_N has detected the magnetism from the permanent magnet 501, the process proceeds to the power-off step S605. When the control unit 302 receives a sensing signal from the magnetic sensor element 201 that is turned on, the control unit 302 measures the position of the magnetic sensor element 201 as the spring position.
In the power-off step S605, the control unit 302 cuts off the power source of the magnetic sensor element 201_N, ends the process of the measurement step S403, and proceeds to the process of the maximum value / minimum value confirmation step S404 in FIG.

In the power-off step S606, the control unit 302 cuts off the power source of the magnetic sensor element 201_N, and proceeds to the process of the management number addition step S607.
In the management number addition step S607, since the magnetic sensor element 201_N has not sensed the magnetism from the permanent magnet 501, the control unit 302 adds 1 to N (N = N + 1), and performs the processing in the management number determination step S602. Transition.

  In the above-described first embodiment, at the time of displacement measurement, not all the magnetic sensor elements 201 are turned on, but the leftmost magnetic sensor elements 201 are turned on one by one to perform magnetic measurement. While the amount of displacement of the spring is not measured, the power source of the displacement sensor 200 is cut off. Furthermore, even when the amount of displacement is being measured, only one magnetic sensor element 201 is powered on. As a result, the power saving of the sensor node 300 can be achieved. In addition, when the magnetic sensor element 201 senses magnetism from the permanent magnet, the measurement process can be completed immediately, so that power consumption can be further suppressed.

In this embodiment, for the sake of convenience, magnetic sensing is performed from the leftmost magnetic sensor element 201. However, magnetic sensing may be started from any magnetic sensor element 201 as long as power is turned on one by one.
In the above-described embodiment, the time interval for executing the measurement is, for example, every hour, and the time interval for transmission is several seconds.
Furthermore, the gateway is mounted on an operation train that uses an overhead line, and the operation train on which the gateway is mounted receives measurement data transmitted at intervals of several seconds during travel and writes it in a recording unit in the operation train. Each measurement data written in the recording section in the operating train is then aggregated and used as maintenance data.

In the first embodiment described above, for example, a series of operations for measuring the spring displacement by turning on the power of the magnetic sensor element 201 in order from the left end of the displacement sensor 200 and sensing the magnetism from the permanent magnet 501 has been described. . However, the amount of spring displacement in STB 101 is about several centimeters per hour. Therefore, for example, if the magnetic sensor element 201 (for example, the magnetic sensor element 201_K) senses magnetism from the permanent magnet 501 in the previous measurement, the magnetic sensor element 201_K or the magnetic sensor element 201_K in the current measurement will be used. There is a high possibility that the magnetic sensor element 201_ (K−1) or 201_ (K + 1) adjacent to the magnetic field senses magnetism (K is a natural number of 1 ≦ K ≦ M).
Therefore, in the second embodiment, the measurement process is completed in a shorter time by starting the measurement process from the magnetic sensor element 201 that is highly likely to sense the magnetism from the permanent magnet 501 based on the previous measurement result. A series of operations will be described with reference to FIG.

Also in the second embodiment, the STB 100 has the same configuration as that of FIGS. 1 and 5 described in the first embodiment. Further, the sensor node 300 having the configuration of FIG. 3 described in the first embodiment is used, and the displacement sensor 200 having the configuration of FIG. 2 described in the first embodiment is used. Similarly, the intermittent operation of the sensor node 300 is the same as the flowchart of FIG. 4 described in the first embodiment.
In the second embodiment, it is assumed that a management number is uniquely assigned to the magnetic sensor element 201. Here, for the sake of convenience, the management number of the leftmost magnetic sensor element 201_1 is 1, the management number of the right-side magnetic sensor element 201_2 is 2, and the management number of the rightmost magnetic sensor element 201_M is M.
Therefore, it is assumed that the displacement sensor 200 is configured with M magnetic sensor elements 201. N is the management number of the magnetic sensor element 201 that sensed magnetism in the previous measurement. Furthermore, L and R are internal variables (L and R are natural numbers).

  Hereinafter, an example of detailed operation of the measurement step S403 in the example of FIG. 4 will be described with reference to FIG. FIG. 7 is a flow chart for explaining an embodiment of the sensor node displacement measuring process of the present invention. This series of operations is executed by the control unit 302 of the sensor node 300 controlling the sensor node 300 and the displacement sensor 200.

When the measurement step S403 is started, in the internal variable initialization step S701, the control unit 302 sets the internal variable L to −1 (L = −1) and sets the internal variable R to 0 (R = 0). (N = 1), the process proceeds to the management number reading step S702.
In the management number reading step S702, the control unit 302 reads the management number N of the magnetic sensor element 201 that senses the magnetism of the permanent magnet 501 in the previous measurement recorded in the recording unit 304, and the management number of the measurement processing step 700 The process proceeds to determination step S703. Note that the measurement processing step 700 is processing from step S703 to step S716 below.

In the management number determination step S703 of the measurement processing step 700, as described above, the management number N is assigned as 1, 2, 3,..., M from the leftmost magnetic sensor element 201. The event that (L + 1) becomes 0 or less is a case where all the left magnetic sensor elements 201 cannot sense magnetism with the magnetic sensor element 201_N as a reference. Therefore, the control unit 302 determines whether N− (L + 1) is 1 or more. When it is determined that N− (L + 1) is 1 or more, the process proceeds to the internal variable L addition step S704. If it is determined that N− (L + 1) is less than 1, the process proceeds to the management number determination step S708.
In the internal variable L addition step S704, the control unit 302 adds 1 to the internal variable L (L = L + 1), and proceeds to the power-on step S705.
In the power-on step S705, the control unit 302 powers on the magnetic sensor element 201_ (N−L), and proceeds to the magnetic detection determination step S706. Since L = −1 in the first measurement, the management number is N, that is, the magnetic sensor element 201_N that has detected magnetism in the previous measurement is turned on. At this time, when the magnetic sensor element 201_ (N−L) to which the power is turned on senses the magnetism of the permanent magnet 501, it outputs a sensing signal to the control unit 302 via the magnetic sensing line 205. If no magnetism is detected, no detection signal is output.

In the magnetic detection determination step S706, the control unit 302 determines whether or not the magnetic sensor element 201_ (N−L) having the management number NL has sensed magnetism from the permanent magnet 501. When it is determined that the magnetic sensor element 201_ (N−L) has detected the magnetism from the permanent magnet 501, the process proceeds to the power-off step S715. When it is determined that the magnetism from the permanent magnet 501 is not sensed, the process proceeds to the power-off step S707.
In the power-off step S715, the control unit 302 cuts off the power source of the magnetic sensor element 201_ (N-L) with the management number NL, ends the process of the measurement step S403, and checks the maximum value / minimum value in FIG. The process proceeds to step S404.

In the power-off step S707, the control unit 302 cuts off the power source of the magnetic sensor element 201_ (N-L) whose management number is NL, and proceeds to the processing of the management number determination step S708.
In the management number determination step S708, it is determined whether or not the management number N + (R + 1) is equal to or smaller than the total number M of the magnetic sensor elements 201. If it is determined that N + (R + 1) ≦ M, the process proceeds to the internal variable R addition step S709. If it is determined that N + (R + 1)> M, the process proceeds to the management number determination step S713.
In the internal variable R addition step S709, the control unit 302 adds 1 to the internal variable R (R = R + 1), and proceeds to the power-on step S710.
In the power-on step S710, the control unit 302 powers on the magnetic sensor element 201_ (N + R) having the management number N + R, and proceeds to the magnetic detection determination step S711. At this time, when the magnetic sensor element 201_ (N + R) to which the power is turned on senses the magnetism of the permanent magnet 501, it outputs a sensing signal to the control unit 302 via the magnetic sensing line 205. If no magnetism is detected, no detection signal is output.

In the magnetic detection determination step S711, the control unit 302 determines whether or not the magnetic sensor element 201_ (N + R) having the management number N + R has sensed magnetism from the permanent magnet 501. When it is determined that the magnetic sensor element 201_ (N + R) has detected the magnetism from the permanent magnet 501, the process proceeds to the power-off step S716. When it is determined that the magnetism from the permanent magnet 501 is not sensed, the process proceeds to the power-off step S712.
In the power-off step S716, the control unit 302 cuts off the power source of the magnetic sensor element 201_ (N + R) having the management number NR, ends the process of the measurement step S403, and checks the maximum value / minimum value check step S404 in FIG. Move on to processing.

In the power-off step S712, the control unit 302 cuts off the power source of the magnetic sensor element 201_ (N + R) whose management number is N + R, and proceeds to the processing of the management number RL determination step S713.
In the management number RL determination step S713, the control unit 302 determines whether or not the magnetic sensing determination has been performed for all the magnetic sensor elements 201. That is, whether the management number N− (L + 1) is equal to the total number M of the magnetic sensor elements 201 or greater than 1, or the management number N + (R + 1) is equal to the total number M of the magnetic sensor elements 201 or It is determined whether or not it is smaller than M. When it is determined that N− (L + 1) ≧ 1 or N + (R + 1) ≦ M, the process proceeds to the management number L determination step S703. When N− (L + 1) <1 and N + (R + 1)> M, the process proceeds to the measurement failure output step S14.
In the measurement failure output step S714, the control unit 302 writes data indicating that the measurement has failed in the recording unit 304 because all the magnetic sensor elements 201 cannot sense the magnetism from the permanent magnet 501.

  In the second embodiment described above, a series of operations for performing magnetic sensing from the magnetic sensor element 201 having a high possibility of sensing magnetism has been described based on the previous measurement result in performing measurement. According to the above-described second embodiment, the displacement amount of the spring in the STB 100 is about several centimeters per hour, and the measurement process is completed at a higher speed than measuring each time, for example, sequentially from the leftmost magnetic sensor element 201. As a result, the power consumption of the measurement process can be suppressed.

As described above, the spring of the STB 100 has a function of making the tension of the overhead wire constant by expanding and contracting according to the tension of the overhead wire. By the way, since a copper wire is generally used for the overhead wire, the expansion / contraction state of the overhead wire greatly depends on the outside air temperature. Therefore, the amount of spring displacement of the STB 100 is also closely related to the outside air temperature.
Therefore, in the third embodiment, the magnetic sensor element 201 that is highly likely to be magnetically sensed in the current measurement is estimated from the difference between the outside temperature at the time of the previous measurement and the current measurement time, and the magnetic sensor element that has been magnetically sensed in the previous measurement. Then, measurement processing is performed from the magnetic sensor element 201 having high possibility. Example 3 will be described with reference to FIGS. 8 and 9.

Also in the third embodiment, the STB 100 has the same configuration as that of FIGS. 1 and 5 described in the first embodiment. Further, the sensor node 300 will be described with the configuration of FIG. 3 described in the first embodiment, and the displacement sensor 200 having the configuration of FIG. 2 described in the first embodiment is used. Similarly, the intermittent operation of the sensor node 300 is the same as the flowchart of FIG. 4 described in the first embodiment.
A third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of an embodiment of the sensor node of the present invention. Reference numeral 800 denotes a sensor node, reference numeral 801 denotes a temperature sensor, and reference numeral 802 denotes a control unit. The sensor node 800 in FIG. 8 adds a temperature sensor 801 that measures the outside air temperature to the sensor node 300 in FIG. 3, replaces the control unit 302 with the control unit 802, and replaces the recording unit 304 with the recording unit 804. Is. Other functions are the same as those in FIG.

In FIG. 8, the temperature sensor 801 measures the outside air temperature at a predetermined time interval and outputs it to the control unit 802 via the LAN 301. In FIG. 8, a temperature sensor 801 is mounted on the sensor node 800 for convenience. However, if the outside air temperature can be measured, for example, the temperature sensor 801 may be mounted on the displacement sensor 200.
The control unit 802 controls the clock unit 303, the recording unit 804, the communication unit 305, the displacement sensor 200, and the temperature sensor 801. A series of operations of the control unit 802 will be described later.
In addition to measurement data (maximum and minimum values of spring displacement), the recording unit 804 records the previous temperature data and the management number J of the magnetic sensor element 200 that sensed magnetism (J is 1). ≦ J ≦ M natural number).
Here, it is assumed that a management number is uniquely assigned to the magnetic sensor element 201. Here, for convenience, the management number of the leftmost magnetic sensor element 201_1 is 1, and the management number of the adjacent magnetic sensor element 201_2 is 2 for convenience. And M is the management number of the rightmost magnetic sensor element 201_M.
Therefore, it is assumed that the displacement sensor 200 is configured with M magnetic sensor elements 201. J is the management number of the magnetic sensor element 201 that sensed magnetism in the previous measurement. Further, L and R are internal variables as in the second embodiment.

The control unit 302 sets J as the management number of the magnetic sensor element that is determined to be most likely to sense magnetism from the difference in the outside air temperature between the previous measurement and the current measurement.
A series of operations of the sensor node 300 according to the third embodiment will be described with reference to FIG. FIG. 9 is a flowchart for explaining an embodiment of the sensor node displacement measuring process of the present invention. However, since the processes denoted by the same reference numerals as those in FIG. 7 described above execute the same processes, the description thereof is omitted as much as possible. This series of operations is executed by the control unit 802 of the sensor node 800 controlling the sensor node 800 and the displacement sensor 200.

When the measurement step S403 is started, in the internal variable initialization step S901, the control unit 802 sets the internal variable L to −1 (L = −1) and sets the internal variable R to 0 (R = 0). (N = 1), the process proceeds to the management number and temperature data reading step S902.
In the management number and temperature data reading step S902, the control unit 302 obtains the previously measured outside air temperature data Tb from the recording unit 804 and the management number Jb of the magnetic sensor element 201 that senses the magnetism of the permanent magnet 501 in the previous measurement. The process proceeds to the reading and temperature measurement step S903.
In the temperature measurement step S903, the control unit 302 measures the outside air temperature T using the temperature sensor 801, and proceeds to the process of the displacement amount estimation step S904.
In the displacement amount estimation step S904, the control unit 302 manages the magnetic sensor element having the highest possibility of sensing magnetism based on the temperature difference ΔT between the outside temperature Tb at the previous measurement and the outside temperature T at the current measurement. The number J is estimated, and the process proceeds to step S700.

In Example 3 described above, it is possible to perform magnetic sensing in the current measurement from the difference ΔT between the external temperature Tb at the previous measurement and the external temperature T at the current measurement, and the magnetic sensor element 201_Jb that has been magnetically sensed in the previous measurement. An example in which a highly probable magnetic sensor element 201 is estimated and measurement processing is performed from the highly probable magnetic sensor element 201 has been described.
In the STB 100, the amount of spring displacement greatly depends on the outside air temperature. For example, it is possible to complete the measurement process at a higher speed than when performing the magnetic sensing determination sequentially from the leftmost magnetic sensor element 201_1. The power consumption of the measurement process can be suppressed.

  As an application of the third embodiment, there is a method of creating a database of the amount of spring displacement with respect to the outside air temperature. Specifically, after measuring the outside air temperature using the temperature sensor 801 when measuring the displacement of the spring, the displacement amount of the spring with respect to the outside air temperature recorded in the database is referred to and measured from the magnetic sensor element 201 having a high possibility. The method of performing a process etc. are mentioned.

In addition, this invention is not limited to above-described Example 1-4, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. In addition, it is possible to add, delete, replace, etc., other parts of the configuration of each embodiment.
Each of the above-described configurations, functions, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be provided in a recording device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.
In addition, the power supply line 204, the magnetic sensing line 205, the ground line 206, and the selection line 207 indicate what is considered necessary for the description, and do not necessarily indicate all the circuits in the product. Actually, it may be considered that almost all the components are connected to each other.

  DESCRIPTION OF SYMBOLS 100: Spring-type automatic tension adjustment apparatus, 101: Storage cylinder, 102: Scale scale, 103: Fixed gauge, 104: Inner inner cylinder, 105: Outer inner cylinder, 150: Overhead wire, 160: Support | pillar, 161, 162: Fixing tool , 200: displacement sensors 200, 201_1, 201_2, 201_3,..., 201_N: magnetic sensor element, 203: demultiplexer, 204: power supply line, 205: magnetic sensing line, 206: ground line, 207: selection line, 300: Sensor node 300: LAN 302: Control unit 303: Clock unit 304: Recording unit 305: Communication unit 502: Connection cable 800: Sensor node 801: Temperature sensor 802: Control unit 804: Recording unit.

Claims (5)

A plurality of magnetic sensor elements for sensing magnetism from a magnet and outputting a magnetic sensing signal;
A displacement sensor comprising: power selection means for selecting a specific magnetic sensor element from the plurality of magnetic sensor elements and supplying power;
Each of the magnetic sensor elements is selected by the power source selection unit and operates when power is supplied. When the magnetic sensor element senses magnetism, it outputs a sensing signal indicating that the magnetism has been sensed .
The displacement sensor;
A clock section that provides time information;
A recording unit for recording the displacement amount of the automatic tension adjusting device as measurement data;
The time information is acquired, and the displacement sensor is controlled if the acquired time information is a measurement time.
Then, the amount of displacement of the automatic tension adjusting device is measured based on the sensing signal from the displacement sensor, and the measurement
Measurement data recorded in the recording unit as data and recorded in the recording unit at the transmission time
A controller for reading out
The control unit supplies power by selecting a specific magnetic sensor element by the power source selection unit.
And determining the position of the magnet based on the sensing signal from the selected magnetic sensor element.
And a management number uniquely assigned to the magnetic sensor element that outputs the sensing signal.
And recording means for recording
Magnetic sensor element that senses magnetism in the previous measurement recorded in the recording means at the time of measurement this time
Is first selected by the power source selection means, and power is supplied.
A sensor node characterized by determining a position. A plurality of magnetic sensor elements for sensing magnetism from a magnet and outputting a magnetic sensing signal;
A power supply for selecting a specific magnetic sensor element from the plurality of magnetic sensor elements and supplying power
A displacement sensor comprising: selection means;
Each of the magnetic sensor elements is selected by the power source selection means and receives power supply.
When it detects the magnetism, it outputs a sensing signal indicating that the magnetism has been sensed,
The displacement sensor;
A clock section that provides time information;
A recording unit that records the length of expansion and contraction of the spring of the automatic tension adjusting device as measurement data;
A communication unit that transmits the measurement data recorded in the recording unit to a gateway;
The time information is acquired, and the displacement sensor is controlled if the acquired time information is a measurement time.
The extension / contraction length of the spring of the automatic tension adjusting device based on the sensing signal from the displacement sensor
Is measured and recorded as measurement data in the recording unit.
A control unit that reads out the measured data and transmits the measurement data to the gateway from the communication unit;
With
The control unit supplies power by selecting a specific magnetic sensor element by the power source selection unit.
And determining the position of the magnet based on the sensing signal from the selected magnetic sensor element.
And a management number uniquely assigned to the magnetic sensor element that outputs the sensing signal.
And recording means for recording
further,
A temperature measuring means for measuring the outside air temperature;
The recording means records the first temperature acquired by the temperature measuring means at the previous measurement and the first management number uniquely assigned to the magnetic sensor element that sensed magnetism at the previous measurement, and the first temperature and Estimating means for estimating the second management number of the magnetic sensor element most likely to sense magnetism during the current measurement from the second temperature acquired by the temperature measurement means during the current measurement and the first management number Have
The control unit first selects a magnetic sensor element to which the second management number obtained by the estimation unit is assigned and an adjacent magnetic sensor element by the power source selection unit, supplies power, and determines the unit by the determination unit. A sensor node for determining a position of a magnet. A plurality of magnetic sensor elements for sensing magnetism from a magnet and outputting a magnetic sensing signal;
A power supply for selecting a specific magnetic sensor element from the plurality of magnetic sensor elements and supplying power
A displacement sensor comprising: selection means;
Each of the magnetic sensor elements is selected by the power source selection means and receives power supply.
When it detects the magnetism, it outputs a sensing signal indicating that the magnetism has been sensed,
The displacement sensor;
A clock section that provides time information;
A recording unit that records the length of expansion and contraction of the spring of the automatic tension adjusting device as measurement data;
A communication unit that transmits the measurement data recorded in the recording unit to a gateway;
The time information is acquired, and the displacement sensor is controlled if the acquired time information is a measurement time.
The extension / contraction length of the spring of the automatic tension adjusting device based on the sensing signal from the displacement sensor
Is measured and recorded as measurement data in the recording unit.
A control unit that reads out the measured data and transmits the measurement data to the gateway from the communication unit;
With
The control unit supplies power by selecting a specific magnetic sensor element by the power source selection unit.
And determining the position of the magnet based on the sensing signal from the selected magnetic sensor element.
And a management number uniquely assigned to the magnetic sensor element that outputs the sensing signal.
And recording means for recording
further,
A temperature measuring means for measuring the outside air temperature;
A database for recording temperature information acquired by the temperature measuring means at the time of past measurement, and a management number uniquely assigned to the magnetic sensor element that senses magnetism;
Determination means for determining a management number of a magnetic sensor element most likely to sense magnetism from temperature information recorded in the database by referring to the database;
Before the measurement, the current temperature is acquired by the temperature measuring unit, and the magnetic sensor element to which the acquired temperature and the management number acquired from the determining unit are assigned, and the adjacent magnetic sensor element are first displayed by the power source selecting unit. sensor node selects, power supplies, and judging a position of said magnet by said determining means. When power is supplied to a plurality of magnetic sensor elements that detect magnetism from a magnet constituting the displacement sensor according to claim 1 and output a magnetic sensing signal, and when a sensing signal is output from the supplied magnetic sensor element An automatic tension measuring method for measuring a displacement amount of the automatic tension adjusting device based on a position of the magnetic sensor element. 5. The automatic tension measuring method according to claim 4 , wherein time information is acquired, a displacement sensor is controlled at a predetermined first time based on the acquired time information, and a sensing signal from the displacement sensor is received. An automatic tension measuring method comprising: measuring a displacement amount of an automatic tension adjusting device based on a magnetic sensor element of the displacement sensor that has received the sensing signal, and recording the measured displacement data.

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